diff options
Diffstat (limited to 'drivers/tty/hvc')
| -rw-r--r-- | drivers/tty/hvc/Kconfig | 134 | ||||
| -rw-r--r-- | drivers/tty/hvc/Makefile | 13 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_console.c | 1069 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_console.h | 113 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_dcc.c | 301 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_irq.c | 55 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_iucv.c | 1427 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_opal.c | 419 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_riscv_sbi.c | 59 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_rtas.c | 110 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_udbg.c | 82 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_vio.c | 473 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_xen.c | 771 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvcs.c | 1571 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvsi.c | 1225 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvsi_lib.c | 424 |
16 files changed, 8246 insertions, 0 deletions
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig new file mode 100644 index 000000000..4f9264d00 --- /dev/null +++ b/drivers/tty/hvc/Kconfig @@ -0,0 +1,134 @@ +# SPDX-License-Identifier: GPL-2.0 + +config HVC_DRIVER + bool + help + Generic "hypervisor virtual console" infrastructure for various + hypervisors (pSeries, iSeries, Xen). + It will automatically be selected if one of the back-end console drivers + is selected. + +config HVC_IRQ + bool + +config HVC_CONSOLE + bool "pSeries Hypervisor Virtual Console support" + depends on PPC_PSERIES + select HVC_DRIVER + select HVC_IRQ + help + pSeries machines when partitioned support a hypervisor virtual + console. This driver allows each pSeries partition to have a console + which is accessed via the HMC. + +config HVC_OLD_HVSI + bool "Old driver for pSeries serial port (/dev/hvsi*)" + depends on HVC_CONSOLE + +config HVC_OPAL + bool "OPAL Console support" + depends on PPC_POWERNV + select HVC_DRIVER + select HVC_IRQ + default y + help + PowerNV machines running under OPAL need that driver to get a console + +config HVC_RTAS + bool "IBM RTAS Console support" + depends on PPC_RTAS + select HVC_DRIVER + help + IBM Console device driver which makes use of RTAS + +config HVC_IUCV + bool "z/VM IUCV Hypervisor console support (VM only)" + depends on S390 && NET + select HVC_DRIVER + select IUCV + default y + help + This driver provides a Hypervisor console (HVC) back-end to access + a Linux (console) terminal via a z/VM IUCV communication path. + +config HVC_XEN + bool "Xen Hypervisor Console support" + depends on XEN + select HVC_DRIVER + select HVC_IRQ + default y + help + Xen virtual console device driver + +config HVC_XEN_FRONTEND + bool "Xen Hypervisor Multiple Consoles support" + depends on HVC_XEN + select XEN_XENBUS_FRONTEND + default y + help + Xen driver for secondary virtual consoles + +config HVC_UDBG + bool "udbg based fake hypervisor console" + depends on PPC + select HVC_DRIVER + help + This is meant to be used during HW bring up or debugging when + no other console mechanism exist but udbg, to get you a quick + console for userspace. Do NOT enable in production kernels. + +config HVC_DCC + bool "ARM JTAG DCC console" + depends on ARM || ARM64 + select HVC_DRIVER + select SERIAL_CORE_CONSOLE + help + This console uses the JTAG DCC on ARM to create a console under the HVC + driver. This console is used through a JTAG only on ARM. If you don't have + a JTAG then you probably don't want this option. + +config HVC_DCC_SERIALIZE_SMP + bool "Use DCC only on CPU core 0" + depends on SMP && HVC_DCC + help + This is a DEBUG option to serialize all console input and output to CPU 0. + Some external debuggers, do not handle reads/writes from/to DCC on more + than one CPU core. Each core has its own DCC device registers, so when a + CPU core reads or writes from/to DCC, it only accesses its own DCC device. + Since kernel code can run on any CPU core, every time the kernel wants to + write to the console, it might write to a different DCC. + + In SMP mode, external debuggers create multiple windows, and each window + shows the DCC output only from that core's DCC. The result is that + console output is either lost or scattered across windows. + + Enable this option only if you are sure that you do not need features like + CPU hotplug to work. For example, during early chipset bringups without + debug serial console support. If unsure, say N. + +config HVC_RISCV_SBI + bool "RISC-V SBI console support" + depends on RISCV_SBI_V01 + select HVC_DRIVER + help + This enables support for console output via RISC-V SBI calls, which + is normally used only during boot to output printk. + + If you don't know what do to here, say Y. + +config HVCS + tristate "IBM Hypervisor Virtual Console Server support" + depends on PPC_PSERIES && HVC_CONSOLE + help + Partitionable IBM Power5 ppc64 machines allow hosting of + firmware virtual consoles from one Linux partition by + another Linux partition. This driver allows console data + from Linux partitions to be accessed through TTY device + interfaces in the device tree of a Linux partition running + this driver. + + To compile this driver as a module, choose M here: the + module will be called hvcs. Additionally, this module + will depend on arch specific APIs exported from hvcserver.ko + which will also be compiled when this driver is built as a + module. diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile new file mode 100644 index 000000000..98880e357 --- /dev/null +++ b/drivers/tty/hvc/Makefile @@ -0,0 +1,13 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o hvsi_lib.o +obj-$(CONFIG_HVC_OPAL) += hvc_opal.o hvsi_lib.o +obj-$(CONFIG_HVC_OLD_HVSI) += hvsi.o +obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o +obj-$(CONFIG_HVC_DCC) += hvc_dcc.o +obj-$(CONFIG_HVC_DRIVER) += hvc_console.o +obj-$(CONFIG_HVC_IRQ) += hvc_irq.o +obj-$(CONFIG_HVC_XEN) += hvc_xen.o +obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o +obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o +obj-$(CONFIG_HVC_RISCV_SBI) += hvc_riscv_sbi.o +obj-$(CONFIG_HVCS) += hvcs.o diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c new file mode 100644 index 000000000..4802cfaa1 --- /dev/null +++ b/drivers/tty/hvc/hvc_console.c @@ -0,0 +1,1069 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM + * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM + * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. + * Copyright (C) 2004 IBM Corporation + * + * Additional Author(s): + * Ryan S. Arnold <rsa@us.ibm.com> + */ + +#include <linux/console.h> +#include <linux/cpumask.h> +#include <linux/init.h> +#include <linux/kbd_kern.h> +#include <linux/kernel.h> +#include <linux/kthread.h> +#include <linux/list.h> +#include <linux/major.h> +#include <linux/atomic.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/delay.h> +#include <linux/freezer.h> +#include <linux/slab.h> +#include <linux/serial_core.h> + +#include <linux/uaccess.h> + +#include "hvc_console.h" + +#define HVC_MAJOR 229 +#define HVC_MINOR 0 + +/* + * Wait this long per iteration while trying to push buffered data to the + * hypervisor before allowing the tty to complete a close operation. + */ +#define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ + +/* + * These sizes are most efficient for vio, because they are the + * native transfer size. We could make them selectable in the + * future to better deal with backends that want other buffer sizes. + */ +#define N_OUTBUF 16 +#define N_INBUF 16 + +#define __ALIGNED__ __attribute__((__aligned__(L1_CACHE_BYTES))) + +static struct tty_driver *hvc_driver; +static struct task_struct *hvc_task; + +/* Picks up late kicks after list walk but before schedule() */ +static int hvc_kicked; + +/* hvc_init is triggered from hvc_alloc, i.e. only when actually used */ +static atomic_t hvc_needs_init __read_mostly = ATOMIC_INIT(-1); + +static int hvc_init(void); + +#ifdef CONFIG_MAGIC_SYSRQ +static int sysrq_pressed; +#endif + +/* dynamic list of hvc_struct instances */ +static LIST_HEAD(hvc_structs); + +/* + * Protect the list of hvc_struct instances from inserts and removals during + * list traversal. + */ +static DEFINE_MUTEX(hvc_structs_mutex); + +/* + * This value is used to assign a tty->index value to a hvc_struct based + * upon order of exposure via hvc_probe(), when we can not match it to + * a console candidate registered with hvc_instantiate(). + */ +static int last_hvc = -1; + +/* + * Do not call this function with either the hvc_structs_mutex or the hvc_struct + * lock held. If successful, this function increments the kref reference + * count against the target hvc_struct so it should be released when finished. + */ +static struct hvc_struct *hvc_get_by_index(int index) +{ + struct hvc_struct *hp; + unsigned long flags; + + mutex_lock(&hvc_structs_mutex); + + list_for_each_entry(hp, &hvc_structs, next) { + spin_lock_irqsave(&hp->lock, flags); + if (hp->index == index) { + tty_port_get(&hp->port); + spin_unlock_irqrestore(&hp->lock, flags); + mutex_unlock(&hvc_structs_mutex); + return hp; + } + spin_unlock_irqrestore(&hp->lock, flags); + } + hp = NULL; + mutex_unlock(&hvc_structs_mutex); + + return hp; +} + +static int __hvc_flush(const struct hv_ops *ops, uint32_t vtermno, bool wait) +{ + if (wait) + might_sleep(); + + if (ops->flush) + return ops->flush(vtermno, wait); + return 0; +} + +static int hvc_console_flush(const struct hv_ops *ops, uint32_t vtermno) +{ + return __hvc_flush(ops, vtermno, false); +} + +/* + * Wait for the console to flush before writing more to it. This sleeps. + */ +static int hvc_flush(struct hvc_struct *hp) +{ + return __hvc_flush(hp->ops, hp->vtermno, true); +} + +/* + * Initial console vtermnos for console API usage prior to full console + * initialization. Any vty adapter outside this range will not have usable + * console interfaces but can still be used as a tty device. This has to be + * static because kmalloc will not work during early console init. + */ +static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; +static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = + {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; + +/* + * Console APIs, NOT TTY. These APIs are available immediately when + * hvc_console_setup() finds adapters. + */ + +static void hvc_console_print(struct console *co, const char *b, + unsigned count) +{ + char c[N_OUTBUF] __ALIGNED__; + unsigned i = 0, n = 0; + int r, donecr = 0, index = co->index; + + /* Console access attempt outside of acceptable console range. */ + if (index >= MAX_NR_HVC_CONSOLES) + return; + + /* This console adapter was removed so it is not usable. */ + if (vtermnos[index] == -1) + return; + + while (count > 0 || i > 0) { + if (count > 0 && i < sizeof(c)) { + if (b[n] == '\n' && !donecr) { + c[i++] = '\r'; + donecr = 1; + } else { + c[i++] = b[n++]; + donecr = 0; + --count; + } + } else { + r = cons_ops[index]->put_chars(vtermnos[index], c, i); + if (r <= 0) { + /* throw away characters on error + * but spin in case of -EAGAIN */ + if (r != -EAGAIN) { + i = 0; + } else { + hvc_console_flush(cons_ops[index], + vtermnos[index]); + } + } else if (r > 0) { + i -= r; + if (i > 0) + memmove(c, c+r, i); + } + } + } + hvc_console_flush(cons_ops[index], vtermnos[index]); +} + +static struct tty_driver *hvc_console_device(struct console *c, int *index) +{ + if (vtermnos[c->index] == -1) + return NULL; + + *index = c->index; + return hvc_driver; +} + +static int hvc_console_setup(struct console *co, char *options) +{ + if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) + return -ENODEV; + + if (vtermnos[co->index] == -1) + return -ENODEV; + + return 0; +} + +static struct console hvc_console = { + .name = "hvc", + .write = hvc_console_print, + .device = hvc_console_device, + .setup = hvc_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +/* + * Early console initialization. Precedes driver initialization. + * + * (1) we are first, and the user specified another driver + * -- index will remain -1 + * (2) we are first and the user specified no driver + * -- index will be set to 0, then we will fail setup. + * (3) we are first and the user specified our driver + * -- index will be set to user specified driver, and we will fail + * (4) we are after driver, and this initcall will register us + * -- if the user didn't specify a driver then the console will match + * + * Note that for cases 2 and 3, we will match later when the io driver + * calls hvc_instantiate() and call register again. + */ +static int __init hvc_console_init(void) +{ + register_console(&hvc_console); + return 0; +} +console_initcall(hvc_console_init); + +/* callback when the kboject ref count reaches zero. */ +static void hvc_port_destruct(struct tty_port *port) +{ + struct hvc_struct *hp = container_of(port, struct hvc_struct, port); + unsigned long flags; + + mutex_lock(&hvc_structs_mutex); + + spin_lock_irqsave(&hp->lock, flags); + list_del(&(hp->next)); + spin_unlock_irqrestore(&hp->lock, flags); + + mutex_unlock(&hvc_structs_mutex); + + kfree(hp); +} + +static void hvc_check_console(int index) +{ + /* Already enabled, bail out */ + if (hvc_console.flags & CON_ENABLED) + return; + + /* If this index is what the user requested, then register + * now (setup won't fail at this point). It's ok to just + * call register again if previously .setup failed. + */ + if (index == hvc_console.index) + register_console(&hvc_console); +} + +/* + * hvc_instantiate() is an early console discovery method which locates + * consoles * prior to the vio subsystem discovering them. Hotplugged + * vty adapters do NOT get an hvc_instantiate() callback since they + * appear after early console init. + */ +int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops) +{ + struct hvc_struct *hp; + + if (index < 0 || index >= MAX_NR_HVC_CONSOLES) + return -1; + + if (vtermnos[index] != -1) + return -1; + + /* make sure no tty has been registered in this index */ + hp = hvc_get_by_index(index); + if (hp) { + tty_port_put(&hp->port); + return -1; + } + + vtermnos[index] = vtermno; + cons_ops[index] = ops; + + /* check if we need to re-register the kernel console */ + hvc_check_console(index); + + return 0; +} +EXPORT_SYMBOL_GPL(hvc_instantiate); + +/* Wake the sleeping khvcd */ +void hvc_kick(void) +{ + hvc_kicked = 1; + wake_up_process(hvc_task); +} +EXPORT_SYMBOL_GPL(hvc_kick); + +static void hvc_unthrottle(struct tty_struct *tty) +{ + hvc_kick(); +} + +static int hvc_install(struct tty_driver *driver, struct tty_struct *tty) +{ + struct hvc_struct *hp; + int rc; + + /* Auto increments kref reference if found. */ + hp = hvc_get_by_index(tty->index); + if (!hp) + return -ENODEV; + + tty->driver_data = hp; + + rc = tty_port_install(&hp->port, driver, tty); + if (rc) + tty_port_put(&hp->port); + return rc; +} + +/* + * The TTY interface won't be used until after the vio layer has exposed the vty + * adapter to the kernel. + */ +static int hvc_open(struct tty_struct *tty, struct file * filp) +{ + struct hvc_struct *hp = tty->driver_data; + unsigned long flags; + int rc = 0; + + spin_lock_irqsave(&hp->port.lock, flags); + /* Check and then increment for fast path open. */ + if (hp->port.count++ > 0) { + spin_unlock_irqrestore(&hp->port.lock, flags); + hvc_kick(); + return 0; + } /* else count == 0 */ + spin_unlock_irqrestore(&hp->port.lock, flags); + + tty_port_tty_set(&hp->port, tty); + + if (hp->ops->notifier_add) + rc = hp->ops->notifier_add(hp, hp->data); + + /* + * If the notifier fails we return an error. The tty layer + * will call hvc_close() after a failed open but we don't want to clean + * up there so we'll clean up here and clear out the previously set + * tty fields and return the kref reference. + */ + if (rc) { + printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); + } else { + /* We are ready... raise DTR/RTS */ + if (C_BAUD(tty)) + if (hp->ops->dtr_rts) + hp->ops->dtr_rts(hp, 1); + tty_port_set_initialized(&hp->port, true); + } + + /* Force wakeup of the polling thread */ + hvc_kick(); + + return rc; +} + +static void hvc_close(struct tty_struct *tty, struct file * filp) +{ + struct hvc_struct *hp = tty->driver_data; + unsigned long flags; + + if (tty_hung_up_p(filp)) + return; + + spin_lock_irqsave(&hp->port.lock, flags); + + if (--hp->port.count == 0) { + spin_unlock_irqrestore(&hp->port.lock, flags); + /* We are done with the tty pointer now. */ + tty_port_tty_set(&hp->port, NULL); + + if (!tty_port_initialized(&hp->port)) + return; + + if (C_HUPCL(tty)) + if (hp->ops->dtr_rts) + hp->ops->dtr_rts(hp, 0); + + if (hp->ops->notifier_del) + hp->ops->notifier_del(hp, hp->data); + + /* cancel pending tty resize work */ + cancel_work_sync(&hp->tty_resize); + + /* + * Chain calls chars_in_buffer() and returns immediately if + * there is no buffered data otherwise sleeps on a wait queue + * waking periodically to check chars_in_buffer(). + */ + tty_wait_until_sent(tty, HVC_CLOSE_WAIT); + tty_port_set_initialized(&hp->port, false); + } else { + if (hp->port.count < 0) + printk(KERN_ERR "hvc_close %X: oops, count is %d\n", + hp->vtermno, hp->port.count); + spin_unlock_irqrestore(&hp->port.lock, flags); + } +} + +static void hvc_cleanup(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + + tty_port_put(&hp->port); +} + +static void hvc_hangup(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + unsigned long flags; + + if (!hp) + return; + + /* cancel pending tty resize work */ + cancel_work_sync(&hp->tty_resize); + + spin_lock_irqsave(&hp->port.lock, flags); + + /* + * The N_TTY line discipline has problems such that in a close vs + * open->hangup case this can be called after the final close so prevent + * that from happening for now. + */ + if (hp->port.count <= 0) { + spin_unlock_irqrestore(&hp->port.lock, flags); + return; + } + + hp->port.count = 0; + spin_unlock_irqrestore(&hp->port.lock, flags); + tty_port_tty_set(&hp->port, NULL); + + hp->n_outbuf = 0; + + if (hp->ops->notifier_hangup) + hp->ops->notifier_hangup(hp, hp->data); +} + +/* + * Push buffered characters whether they were just recently buffered or waiting + * on a blocked hypervisor. Call this function with hp->lock held. + */ +static int hvc_push(struct hvc_struct *hp) +{ + int n; + + n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); + if (n <= 0) { + if (n == 0 || n == -EAGAIN) { + hp->do_wakeup = 1; + return 0; + } + /* throw away output on error; this happens when + there is no session connected to the vterm. */ + hp->n_outbuf = 0; + } else + hp->n_outbuf -= n; + if (hp->n_outbuf > 0) + memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); + else + hp->do_wakeup = 1; + + return n; +} + +static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) +{ + struct hvc_struct *hp = tty->driver_data; + unsigned long flags; + int rsize, written = 0; + + /* This write was probably executed during a tty close. */ + if (!hp) + return -EPIPE; + + /* FIXME what's this (unprotected) check for? */ + if (hp->port.count <= 0) + return -EIO; + + while (count > 0) { + int ret = 0; + + spin_lock_irqsave(&hp->lock, flags); + + rsize = hp->outbuf_size - hp->n_outbuf; + + if (rsize) { + if (rsize > count) + rsize = count; + memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); + count -= rsize; + buf += rsize; + hp->n_outbuf += rsize; + written += rsize; + } + + if (hp->n_outbuf > 0) + ret = hvc_push(hp); + + spin_unlock_irqrestore(&hp->lock, flags); + + if (!ret) + break; + + if (count) { + if (hp->n_outbuf > 0) + hvc_flush(hp); + cond_resched(); + } + } + + /* + * Racy, but harmless, kick thread if there is still pending data. + */ + if (hp->n_outbuf) + hvc_kick(); + + return written; +} + +/** + * hvc_set_winsz() - Resize the hvc tty terminal window. + * @work: work structure. + * + * The routine shall not be called within an atomic context because it + * might sleep. + * + * Locking: hp->lock + */ +static void hvc_set_winsz(struct work_struct *work) +{ + struct hvc_struct *hp; + unsigned long hvc_flags; + struct tty_struct *tty; + struct winsize ws; + + hp = container_of(work, struct hvc_struct, tty_resize); + + tty = tty_port_tty_get(&hp->port); + if (!tty) + return; + + spin_lock_irqsave(&hp->lock, hvc_flags); + ws = hp->ws; + spin_unlock_irqrestore(&hp->lock, hvc_flags); + + tty_do_resize(tty, &ws); + tty_kref_put(tty); +} + +/* + * This is actually a contract between the driver and the tty layer outlining + * how much write room the driver can guarantee will be sent OR BUFFERED. This + * driver MUST honor the return value. + */ +static unsigned int hvc_write_room(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + + if (!hp) + return 0; + + return hp->outbuf_size - hp->n_outbuf; +} + +static unsigned int hvc_chars_in_buffer(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + + if (!hp) + return 0; + return hp->n_outbuf; +} + +/* + * timeout will vary between the MIN and MAX values defined here. By default + * and during console activity we will use a default MIN_TIMEOUT of 10. When + * the console is idle, we increase the timeout value on each pass through + * msleep until we reach the max. This may be noticeable as a brief (average + * one second) delay on the console before the console responds to input when + * there has been no input for some time. + */ +#define MIN_TIMEOUT (10) +#define MAX_TIMEOUT (2000) +static u32 timeout = MIN_TIMEOUT; + +/* + * Maximum number of bytes to get from the console driver if hvc_poll is + * called from driver (and can't sleep). Any more than this and we break + * and start polling with khvcd. This value was derived from an OpenBMC + * console with the OPAL driver that results in about 0.25ms interrupts off + * latency. + */ +#define HVC_ATOMIC_READ_MAX 128 + +#define HVC_POLL_READ 0x00000001 +#define HVC_POLL_WRITE 0x00000002 + +static int __hvc_poll(struct hvc_struct *hp, bool may_sleep) +{ + struct tty_struct *tty; + int i, n, count, poll_mask = 0; + char buf[N_INBUF] __ALIGNED__; + unsigned long flags; + int read_total = 0; + int written_total = 0; + + spin_lock_irqsave(&hp->lock, flags); + + /* Push pending writes */ + if (hp->n_outbuf > 0) + written_total = hvc_push(hp); + + /* Reschedule us if still some write pending */ + if (hp->n_outbuf > 0) { + poll_mask |= HVC_POLL_WRITE; + /* If hvc_push() was not able to write, sleep a few msecs */ + timeout = (written_total) ? 0 : MIN_TIMEOUT; + } + + if (may_sleep) { + spin_unlock_irqrestore(&hp->lock, flags); + cond_resched(); + spin_lock_irqsave(&hp->lock, flags); + } + + /* No tty attached, just skip */ + tty = tty_port_tty_get(&hp->port); + if (tty == NULL) + goto bail; + + /* Now check if we can get data (are we throttled ?) */ + if (tty_throttled(tty)) + goto out; + + /* If we aren't notifier driven and aren't throttled, we always + * request a reschedule + */ + if (!hp->irq_requested) + poll_mask |= HVC_POLL_READ; + + read_again: + /* Read data if any */ + count = tty_buffer_request_room(&hp->port, N_INBUF); + + /* If flip is full, just reschedule a later read */ + if (count == 0) { + poll_mask |= HVC_POLL_READ; + goto out; + } + + n = hp->ops->get_chars(hp->vtermno, buf, count); + if (n <= 0) { + /* Hangup the tty when disconnected from host */ + if (n == -EPIPE) { + spin_unlock_irqrestore(&hp->lock, flags); + tty_hangup(tty); + spin_lock_irqsave(&hp->lock, flags); + } else if ( n == -EAGAIN ) { + /* + * Some back-ends can only ensure a certain min + * num of bytes read, which may be > 'count'. + * Let the tty clear the flip buff to make room. + */ + poll_mask |= HVC_POLL_READ; + } + goto out; + } + + for (i = 0; i < n; ++i) { +#ifdef CONFIG_MAGIC_SYSRQ + if (hp->index == hvc_console.index) { + /* Handle the SysRq Hack */ + /* XXX should support a sequence */ + if (buf[i] == '\x0f') { /* ^O */ + /* if ^O is pressed again, reset + * sysrq_pressed and flip ^O char */ + sysrq_pressed = !sysrq_pressed; + if (sysrq_pressed) + continue; + } else if (sysrq_pressed) { + handle_sysrq(buf[i]); + sysrq_pressed = 0; + continue; + } + } +#endif /* CONFIG_MAGIC_SYSRQ */ + tty_insert_flip_char(&hp->port, buf[i], 0); + } + read_total += n; + + if (may_sleep) { + /* Keep going until the flip is full */ + spin_unlock_irqrestore(&hp->lock, flags); + cond_resched(); + spin_lock_irqsave(&hp->lock, flags); + goto read_again; + } else if (read_total < HVC_ATOMIC_READ_MAX) { + /* Break and defer if it's a large read in atomic */ + goto read_again; + } + + /* + * Latency break, schedule another poll immediately. + */ + poll_mask |= HVC_POLL_READ; + + out: + /* Wakeup write queue if necessary */ + if (hp->do_wakeup) { + hp->do_wakeup = 0; + tty_wakeup(tty); + } + bail: + spin_unlock_irqrestore(&hp->lock, flags); + + if (read_total) { + /* Activity is occurring, so reset the polling backoff value to + a minimum for performance. */ + timeout = MIN_TIMEOUT; + + tty_flip_buffer_push(&hp->port); + } + tty_kref_put(tty); + + return poll_mask; +} + +int hvc_poll(struct hvc_struct *hp) +{ + return __hvc_poll(hp, false); +} +EXPORT_SYMBOL_GPL(hvc_poll); + +/** + * __hvc_resize() - Update terminal window size information. + * @hp: HVC console pointer + * @ws: Terminal window size structure + * + * Stores the specified window size information in the hvc structure of @hp. + * The function schedule the tty resize update. + * + * Locking: Locking free; the function MUST be called holding hp->lock + */ +void __hvc_resize(struct hvc_struct *hp, struct winsize ws) +{ + hp->ws = ws; + schedule_work(&hp->tty_resize); +} +EXPORT_SYMBOL_GPL(__hvc_resize); + +/* + * This kthread is either polling or interrupt driven. This is determined by + * calling hvc_poll() who determines whether a console adapter support + * interrupts. + */ +static int khvcd(void *unused) +{ + int poll_mask; + struct hvc_struct *hp; + + set_freezable(); + do { + poll_mask = 0; + hvc_kicked = 0; + try_to_freeze(); + wmb(); + if (!cpus_are_in_xmon()) { + mutex_lock(&hvc_structs_mutex); + list_for_each_entry(hp, &hvc_structs, next) { + poll_mask |= __hvc_poll(hp, true); + cond_resched(); + } + mutex_unlock(&hvc_structs_mutex); + } else + poll_mask |= HVC_POLL_READ; + if (hvc_kicked) + continue; + set_current_state(TASK_INTERRUPTIBLE); + if (!hvc_kicked) { + if (poll_mask == 0) + schedule(); + else { + unsigned long j_timeout; + + if (timeout < MAX_TIMEOUT) + timeout += (timeout >> 6) + 1; + + /* + * We don't use msleep_interruptible otherwise + * "kick" will fail to wake us up + */ + j_timeout = msecs_to_jiffies(timeout) + 1; + schedule_timeout_interruptible(j_timeout); + } + } + __set_current_state(TASK_RUNNING); + } while (!kthread_should_stop()); + + return 0; +} + +static int hvc_tiocmget(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + + if (!hp || !hp->ops->tiocmget) + return -EINVAL; + return hp->ops->tiocmget(hp); +} + +static int hvc_tiocmset(struct tty_struct *tty, + unsigned int set, unsigned int clear) +{ + struct hvc_struct *hp = tty->driver_data; + + if (!hp || !hp->ops->tiocmset) + return -EINVAL; + return hp->ops->tiocmset(hp, set, clear); +} + +#ifdef CONFIG_CONSOLE_POLL +static int hvc_poll_init(struct tty_driver *driver, int line, char *options) +{ + return 0; +} + +static int hvc_poll_get_char(struct tty_driver *driver, int line) +{ + struct tty_struct *tty = driver->ttys[0]; + struct hvc_struct *hp = tty->driver_data; + int n; + char ch; + + n = hp->ops->get_chars(hp->vtermno, &ch, 1); + + if (n <= 0) + return NO_POLL_CHAR; + + return ch; +} + +static void hvc_poll_put_char(struct tty_driver *driver, int line, char ch) +{ + struct tty_struct *tty = driver->ttys[0]; + struct hvc_struct *hp = tty->driver_data; + int n; + + do { + n = hp->ops->put_chars(hp->vtermno, &ch, 1); + } while (n <= 0); +} +#endif + +static const struct tty_operations hvc_ops = { + .install = hvc_install, + .open = hvc_open, + .close = hvc_close, + .cleanup = hvc_cleanup, + .write = hvc_write, + .hangup = hvc_hangup, + .unthrottle = hvc_unthrottle, + .write_room = hvc_write_room, + .chars_in_buffer = hvc_chars_in_buffer, + .tiocmget = hvc_tiocmget, + .tiocmset = hvc_tiocmset, +#ifdef CONFIG_CONSOLE_POLL + .poll_init = hvc_poll_init, + .poll_get_char = hvc_poll_get_char, + .poll_put_char = hvc_poll_put_char, +#endif +}; + +static const struct tty_port_operations hvc_port_ops = { + .destruct = hvc_port_destruct, +}; + +struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, + const struct hv_ops *ops, + int outbuf_size) +{ + struct hvc_struct *hp; + int i; + + /* We wait until a driver actually comes along */ + if (atomic_inc_not_zero(&hvc_needs_init)) { + int err = hvc_init(); + if (err) + return ERR_PTR(err); + } + + hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, + GFP_KERNEL); + if (!hp) + return ERR_PTR(-ENOMEM); + + hp->vtermno = vtermno; + hp->data = data; + hp->ops = ops; + hp->outbuf_size = outbuf_size; + hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; + + tty_port_init(&hp->port); + hp->port.ops = &hvc_port_ops; + + INIT_WORK(&hp->tty_resize, hvc_set_winsz); + spin_lock_init(&hp->lock); + mutex_lock(&hvc_structs_mutex); + + /* + * find index to use: + * see if this vterm id matches one registered for console. + */ + for (i=0; i < MAX_NR_HVC_CONSOLES; i++) + if (vtermnos[i] == hp->vtermno && + cons_ops[i] == hp->ops) + break; + + if (i >= MAX_NR_HVC_CONSOLES) { + + /* find 'empty' slot for console */ + for (i = 0; i < MAX_NR_HVC_CONSOLES && vtermnos[i] != -1; i++) { + } + + /* no matching slot, just use a counter */ + if (i == MAX_NR_HVC_CONSOLES) + i = ++last_hvc + MAX_NR_HVC_CONSOLES; + } + + hp->index = i; + if (i < MAX_NR_HVC_CONSOLES) { + cons_ops[i] = ops; + vtermnos[i] = vtermno; + } + + list_add_tail(&(hp->next), &hvc_structs); + mutex_unlock(&hvc_structs_mutex); + + /* check if we need to re-register the kernel console */ + hvc_check_console(i); + + return hp; +} +EXPORT_SYMBOL_GPL(hvc_alloc); + +int hvc_remove(struct hvc_struct *hp) +{ + unsigned long flags; + struct tty_struct *tty; + + tty = tty_port_tty_get(&hp->port); + + console_lock(); + spin_lock_irqsave(&hp->lock, flags); + if (hp->index < MAX_NR_HVC_CONSOLES) { + vtermnos[hp->index] = -1; + cons_ops[hp->index] = NULL; + } + + /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ + + spin_unlock_irqrestore(&hp->lock, flags); + console_unlock(); + + /* + * We 'put' the instance that was grabbed when the kref instance + * was initialized using kref_init(). Let the last holder of this + * kref cause it to be removed, which will probably be the tty_vhangup + * below. + */ + tty_port_put(&hp->port); + + /* + * This function call will auto chain call hvc_hangup. + */ + if (tty) { + tty_vhangup(tty); + tty_kref_put(tty); + } + return 0; +} +EXPORT_SYMBOL_GPL(hvc_remove); + +/* Driver initialization: called as soon as someone uses hvc_alloc(). */ +static int hvc_init(void) +{ + struct tty_driver *drv; + int err; + + /* We need more than hvc_count adapters due to hotplug additions. */ + drv = tty_alloc_driver(HVC_ALLOC_TTY_ADAPTERS, TTY_DRIVER_REAL_RAW | + TTY_DRIVER_RESET_TERMIOS); + if (IS_ERR(drv)) { + err = PTR_ERR(drv); + goto out; + } + + drv->driver_name = "hvc"; + drv->name = "hvc"; + drv->major = HVC_MAJOR; + drv->minor_start = HVC_MINOR; + drv->type = TTY_DRIVER_TYPE_SYSTEM; + drv->init_termios = tty_std_termios; + tty_set_operations(drv, &hvc_ops); + + /* Always start the kthread because there can be hotplug vty adapters + * added later. */ + hvc_task = kthread_run(khvcd, NULL, "khvcd"); + if (IS_ERR(hvc_task)) { + printk(KERN_ERR "Couldn't create kthread for console.\n"); + err = PTR_ERR(hvc_task); + goto put_tty; + } + + err = tty_register_driver(drv); + if (err) { + printk(KERN_ERR "Couldn't register hvc console driver\n"); + goto stop_thread; + } + + /* + * Make sure tty is fully registered before allowing it to be + * found by hvc_console_device. + */ + smp_mb(); + hvc_driver = drv; + return 0; + +stop_thread: + kthread_stop(hvc_task); + hvc_task = NULL; +put_tty: + tty_driver_kref_put(drv); +out: + return err; +} diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h new file mode 100644 index 000000000..18d005814 --- /dev/null +++ b/drivers/tty/hvc/hvc_console.h @@ -0,0 +1,113 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * hvc_console.h + * Copyright (C) 2005 IBM Corporation + * + * Author(s): + * Ryan S. Arnold <rsa@us.ibm.com> + * + * hvc_console header information: + * moved here from arch/powerpc/include/asm/hvconsole.h + * and drivers/char/hvc_console.c + */ + +#ifndef HVC_CONSOLE_H +#define HVC_CONSOLE_H +#include <linux/kref.h> +#include <linux/tty.h> +#include <linux/spinlock.h> + +/* + * This is the max number of console adapters that can/will be found as + * console devices on first stage console init. Any number beyond this range + * can't be used as a console device but is still a valid tty device. + */ +#define MAX_NR_HVC_CONSOLES 16 + +/* + * The Linux TTY code does not support dynamic addition of tty derived devices + * so we need to know how many tty devices we might need when space is allocated + * for the tty device. Since this driver supports hotplug of vty adapters we + * need to make sure we have enough allocated. + */ +#define HVC_ALLOC_TTY_ADAPTERS 8 + +struct hvc_struct { + struct tty_port port; + spinlock_t lock; + int index; + int do_wakeup; + char *outbuf; + int outbuf_size; + int n_outbuf; + uint32_t vtermno; + const struct hv_ops *ops; + int irq_requested; + int data; + struct winsize ws; + struct work_struct tty_resize; + struct list_head next; + unsigned long flags; +}; + +/* implemented by a low level driver */ +struct hv_ops { + int (*get_chars)(uint32_t vtermno, char *buf, int count); + int (*put_chars)(uint32_t vtermno, const char *buf, int count); + int (*flush)(uint32_t vtermno, bool wait); + + /* Callbacks for notification. Called in open, close and hangup */ + int (*notifier_add)(struct hvc_struct *hp, int irq); + void (*notifier_del)(struct hvc_struct *hp, int irq); + void (*notifier_hangup)(struct hvc_struct *hp, int irq); + + /* tiocmget/set implementation */ + int (*tiocmget)(struct hvc_struct *hp); + int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear); + + /* Callbacks to handle tty ports */ + void (*dtr_rts)(struct hvc_struct *hp, int raise); +}; + +/* Register a vterm and a slot index for use as a console (console_init) */ +extern int hvc_instantiate(uint32_t vtermno, int index, + const struct hv_ops *ops); + +/* register a vterm for hvc tty operation (module_init or hotplug add) */ +extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data, + const struct hv_ops *ops, int outbuf_size); +/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */ +extern int hvc_remove(struct hvc_struct *hp); + +/* data available */ +int hvc_poll(struct hvc_struct *hp); +void hvc_kick(void); + +/* Resize hvc tty terminal window */ +extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws); + +static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws) +{ + unsigned long flags; + + spin_lock_irqsave(&hp->lock, flags); + __hvc_resize(hp, ws); + spin_unlock_irqrestore(&hp->lock, flags); +} + +/* default notifier for irq based notification */ +extern int notifier_add_irq(struct hvc_struct *hp, int data); +extern void notifier_del_irq(struct hvc_struct *hp, int data); +extern void notifier_hangup_irq(struct hvc_struct *hp, int data); + + +#if defined(CONFIG_XMON) && defined(CONFIG_SMP) +#include <asm/xmon.h> +#else +static inline int cpus_are_in_xmon(void) +{ + return 0; +} +#endif + +#endif // HVC_CONSOLE_H diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c new file mode 100644 index 000000000..1751108cf --- /dev/null +++ b/drivers/tty/hvc/hvc_dcc.c @@ -0,0 +1,301 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2010, 2014, 2022 The Linux Foundation. All rights reserved. */ + +#include <linux/console.h> +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/init.h> +#include <linux/kfifo.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/smp.h> +#include <linux/spinlock.h> + +#include <asm/dcc.h> +#include <asm/processor.h> + +#include "hvc_console.h" + +/* DCC Status Bits */ +#define DCC_STATUS_RX (1 << 30) +#define DCC_STATUS_TX (1 << 29) + +#define DCC_INBUF_SIZE 128 +#define DCC_OUTBUF_SIZE 1024 + +/* Lock to serialize access to DCC fifo */ +static DEFINE_SPINLOCK(dcc_lock); + +static DEFINE_KFIFO(inbuf, unsigned char, DCC_INBUF_SIZE); +static DEFINE_KFIFO(outbuf, unsigned char, DCC_OUTBUF_SIZE); + +static void dcc_uart_console_putchar(struct uart_port *port, unsigned char ch) +{ + while (__dcc_getstatus() & DCC_STATUS_TX) + cpu_relax(); + + __dcc_putchar(ch); +} + +static void dcc_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, dcc_uart_console_putchar); +} + +static int __init dcc_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + device->con->write = dcc_early_write; + + return 0; +} + +EARLYCON_DECLARE(dcc, dcc_early_console_setup); + +static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count) +{ + int i; + + for (i = 0; i < count; i++) { + while (__dcc_getstatus() & DCC_STATUS_TX) + cpu_relax(); + + __dcc_putchar(buf[i]); + } + + return count; +} + +static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count) +{ + int i; + + for (i = 0; i < count; ++i) + if (__dcc_getstatus() & DCC_STATUS_RX) + buf[i] = __dcc_getchar(); + else + break; + + return i; +} + +/* + * Check if the DCC is enabled. If CONFIG_HVC_DCC_SERIALIZE_SMP is enabled, + * then we assume then this function will be called first on core0. That way, + * dcc_core0_available will be true only if it's available on core0. + */ +static bool hvc_dcc_check(void) +{ + unsigned long time = jiffies + (HZ / 10); + static bool dcc_core0_available; + + /* + * If we're not on core 0, but we previously confirmed that DCC is + * active, then just return true. + */ + int cpu = get_cpu(); + + if (IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP) && cpu && dcc_core0_available) { + put_cpu(); + return true; + } + + put_cpu(); + + /* Write a test character to check if it is handled */ + __dcc_putchar('\n'); + + while (time_is_after_jiffies(time)) { + if (!(__dcc_getstatus() & DCC_STATUS_TX)) { + dcc_core0_available = true; + return true; + } + } + + return false; +} + +/* + * Workqueue function that writes the output FIFO to the DCC on core 0. + */ +static void dcc_put_work(struct work_struct *work) +{ + unsigned char ch; + unsigned long irqflags; + + spin_lock_irqsave(&dcc_lock, irqflags); + + /* While there's data in the output FIFO, write it to the DCC */ + while (kfifo_get(&outbuf, &ch)) + hvc_dcc_put_chars(0, &ch, 1); + + /* While we're at it, check for any input characters */ + while (!kfifo_is_full(&inbuf)) { + if (!hvc_dcc_get_chars(0, &ch, 1)) + break; + kfifo_put(&inbuf, ch); + } + + spin_unlock_irqrestore(&dcc_lock, irqflags); +} + +static DECLARE_WORK(dcc_pwork, dcc_put_work); + +/* + * Workqueue function that reads characters from DCC and puts them into the + * input FIFO. + */ +static void dcc_get_work(struct work_struct *work) +{ + unsigned char ch; + unsigned long irqflags; + + /* + * Read characters from DCC and put them into the input FIFO, as + * long as there is room and we have characters to read. + */ + spin_lock_irqsave(&dcc_lock, irqflags); + + while (!kfifo_is_full(&inbuf)) { + if (!hvc_dcc_get_chars(0, &ch, 1)) + break; + kfifo_put(&inbuf, ch); + } + spin_unlock_irqrestore(&dcc_lock, irqflags); +} + +static DECLARE_WORK(dcc_gwork, dcc_get_work); + +/* + * Write characters directly to the DCC if we're on core 0 and the FIFO + * is empty, or write them to the FIFO if we're not. + */ +static int hvc_dcc0_put_chars(u32 vt, const char *buf, int count) +{ + int len; + unsigned long irqflags; + + if (!IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP)) + return hvc_dcc_put_chars(vt, buf, count); + + spin_lock_irqsave(&dcc_lock, irqflags); + if (smp_processor_id() || (!kfifo_is_empty(&outbuf))) { + len = kfifo_in(&outbuf, buf, count); + spin_unlock_irqrestore(&dcc_lock, irqflags); + + /* + * We just push data to the output FIFO, so schedule the + * workqueue that will actually write that data to DCC. + * CPU hotplug is disabled in dcc_init so CPU0 cannot be + * offlined after the cpu online check. + */ + if (cpu_online(0)) + schedule_work_on(0, &dcc_pwork); + + return len; + } + + /* + * If we're already on core 0, and the FIFO is empty, then just + * write the data to DCC. + */ + len = hvc_dcc_put_chars(vt, buf, count); + spin_unlock_irqrestore(&dcc_lock, irqflags); + + return len; +} + +/* + * Read characters directly from the DCC if we're on core 0 and the FIFO + * is empty, or read them from the FIFO if we're not. + */ +static int hvc_dcc0_get_chars(u32 vt, char *buf, int count) +{ + int len; + unsigned long irqflags; + + if (!IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP)) + return hvc_dcc_get_chars(vt, buf, count); + + spin_lock_irqsave(&dcc_lock, irqflags); + + if (smp_processor_id() || (!kfifo_is_empty(&inbuf))) { + len = kfifo_out(&inbuf, buf, count); + spin_unlock_irqrestore(&dcc_lock, irqflags); + + /* + * If the FIFO was empty, there may be characters in the DCC + * that we haven't read yet. Schedule a workqueue to fill + * the input FIFO, so that the next time this function is + * called, we'll have data. CPU hotplug is disabled in dcc_init + * so CPU0 cannot be offlined after the cpu online check. + */ + if (!len && cpu_online(0)) + schedule_work_on(0, &dcc_gwork); + + return len; + } + + /* + * If we're already on core 0, and the FIFO is empty, then just + * read the data from DCC. + */ + len = hvc_dcc_get_chars(vt, buf, count); + spin_unlock_irqrestore(&dcc_lock, irqflags); + + return len; +} + +static const struct hv_ops hvc_dcc_get_put_ops = { + .get_chars = hvc_dcc0_get_chars, + .put_chars = hvc_dcc0_put_chars, +}; + +static int __init hvc_dcc_console_init(void) +{ + int ret; + + if (!hvc_dcc_check()) + return -ENODEV; + + /* Returns -1 if error */ + ret = hvc_instantiate(0, 0, &hvc_dcc_get_put_ops); + + return ret < 0 ? -ENODEV : 0; +} +console_initcall(hvc_dcc_console_init); + +static int __init hvc_dcc_init(void) +{ + struct hvc_struct *p; + + if (!hvc_dcc_check()) + return -ENODEV; + + if (IS_ENABLED(CONFIG_HVC_DCC_SERIALIZE_SMP)) { + pr_warn("\n"); + pr_warn("********************************************************************\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("** **\n"); + pr_warn("** HVC_DCC_SERIALIZE_SMP SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n"); + pr_warn("** **\n"); + pr_warn("** This means that this is a DEBUG kernel and unsafe for **\n"); + pr_warn("** production use and has important feature like CPU hotplug **\n"); + pr_warn("** disabled. **\n"); + pr_warn("** **\n"); + pr_warn("** If you see this message and you are not debugging the **\n"); + pr_warn("** kernel, report this immediately to your vendor! **\n"); + pr_warn("** **\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("********************************************************************\n"); + + cpu_hotplug_disable(); + } + + p = hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128); + + return PTR_ERR_OR_ZERO(p); +} +device_initcall(hvc_dcc_init); diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c new file mode 100644 index 000000000..4b255dfef --- /dev/null +++ b/drivers/tty/hvc/hvc_irq.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2001,2008 + * + * This file contains the IRQ specific code for hvc_console + * + */ + +#include <linux/interrupt.h> + +#include "hvc_console.h" + +static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance) +{ + /* if hvc_poll request a repoll, then kick the hvcd thread */ + if (hvc_poll(dev_instance)) + hvc_kick(); + + /* + * We're safe to always return IRQ_HANDLED as the hvcd thread will + * iterate through each hvc_struct. + */ + return IRQ_HANDLED; +} + +/* + * For IRQ based systems these callbacks can be used + */ +int notifier_add_irq(struct hvc_struct *hp, int irq) +{ + int rc; + + if (!irq) { + hp->irq_requested = 0; + return 0; + } + rc = request_irq(irq, hvc_handle_interrupt, hp->flags, + "hvc_console", hp); + if (!rc) + hp->irq_requested = 1; + return rc; +} + +void notifier_del_irq(struct hvc_struct *hp, int irq) +{ + if (!hp->irq_requested) + return; + free_irq(irq, hp); + hp->irq_requested = 0; +} + +void notifier_hangup_irq(struct hvc_struct *hp, int irq) +{ + notifier_del_irq(hp, irq); +} diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c new file mode 100644 index 000000000..7d49a872d --- /dev/null +++ b/drivers/tty/hvc/hvc_iucv.c @@ -0,0 +1,1427 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * z/VM IUCV hypervisor console (HVC) device driver + * + * This HVC device driver provides terminal access using + * z/VM IUCV communication paths. + * + * Copyright IBM Corp. 2008, 2013 + * + * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> + */ +#define KMSG_COMPONENT "hvc_iucv" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/types.h> +#include <linux/slab.h> +#include <asm/ebcdic.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/mempool.h> +#include <linux/moduleparam.h> +#include <linux/tty.h> +#include <linux/wait.h> +#include <net/iucv/iucv.h> + +#include "hvc_console.h" + + +/* General device driver settings */ +#define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS +#define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4) + +/* IUCV TTY message */ +#define MSG_VERSION 0x02 /* Message version */ +#define MSG_TYPE_ERROR 0x01 /* Error message */ +#define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ +#define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ +#define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ +#define MSG_TYPE_DATA 0x10 /* Terminal data */ + +struct iucv_tty_msg { + u8 version; /* Message version */ + u8 type; /* Message type */ +#define MSG_MAX_DATALEN ((u16)(~0)) + u16 datalen; /* Payload length */ + u8 data[]; /* Payload buffer */ +} __attribute__((packed)); +#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) + +enum iucv_state_t { + IUCV_DISCONN = 0, + IUCV_CONNECTED = 1, + IUCV_SEVERED = 2, +}; + +enum tty_state_t { + TTY_CLOSED = 0, + TTY_OPENED = 1, +}; + +struct hvc_iucv_private { + struct hvc_struct *hvc; /* HVC struct reference */ + u8 srv_name[8]; /* IUCV service name (ebcdic) */ + unsigned char is_console; /* Linux console usage flag */ + enum iucv_state_t iucv_state; /* IUCV connection status */ + enum tty_state_t tty_state; /* TTY status */ + struct iucv_path *path; /* IUCV path pointer */ + spinlock_t lock; /* hvc_iucv_private lock */ +#define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */ + void *sndbuf; /* send buffer */ + size_t sndbuf_len; /* length of send buffer */ +#define QUEUE_SNDBUF_DELAY (HZ / 25) + struct delayed_work sndbuf_work; /* work: send iucv msg(s) */ + wait_queue_head_t sndbuf_waitq; /* wait for send completion */ + struct list_head tty_outqueue; /* outgoing IUCV messages */ + struct list_head tty_inqueue; /* incoming IUCV messages */ + struct device *dev; /* device structure */ + u8 info_path[16]; /* IUCV path info (dev attr) */ +}; + +struct iucv_tty_buffer { + struct list_head list; /* list pointer */ + struct iucv_message msg; /* store an IUCV message */ + size_t offset; /* data buffer offset */ + struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ +}; + +/* IUCV callback handler */ +static int hvc_iucv_path_pending(struct iucv_path *, u8 *, u8 *); +static void hvc_iucv_path_severed(struct iucv_path *, u8 *); +static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); +static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); + + +/* Kernel module parameter: use one terminal device as default */ +static unsigned long hvc_iucv_devices = 1; + +/* Array of allocated hvc iucv tty lines... */ +static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; +#define IUCV_HVC_CON_IDX (0) +/* List of z/VM user ID filter entries (struct iucv_vmid_filter) */ +#define MAX_VMID_FILTER (500) +#define FILTER_WILDCARD_CHAR '*' +static size_t hvc_iucv_filter_size; +static void *hvc_iucv_filter; +static const char *hvc_iucv_filter_string; +static DEFINE_RWLOCK(hvc_iucv_filter_lock); + +/* Kmem cache and mempool for iucv_tty_buffer elements */ +static struct kmem_cache *hvc_iucv_buffer_cache; +static mempool_t *hvc_iucv_mempool; + +/* IUCV handler callback functions */ +static struct iucv_handler hvc_iucv_handler = { + .path_pending = hvc_iucv_path_pending, + .path_severed = hvc_iucv_path_severed, + .message_complete = hvc_iucv_msg_complete, + .message_pending = hvc_iucv_msg_pending, +}; + + +/** + * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. + * @num: The HVC virtual terminal number (vtermno) + * + * This function returns the struct hvc_iucv_private instance that corresponds + * to the HVC virtual terminal number specified as parameter @num. + */ +static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) +{ + if (num > hvc_iucv_devices) + return NULL; + return hvc_iucv_table[num]; +} + +/** + * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. + * @size: Size of the internal buffer used to store data. + * @flags: Memory allocation flags passed to mempool. + * + * This function allocates a new struct iucv_tty_buffer element and, optionally, + * allocates an internal data buffer with the specified size @size. + * The internal data buffer is always allocated with GFP_DMA which is + * required for receiving and sending data with IUCV. + * Note: The total message size arises from the internal buffer size and the + * members of the iucv_tty_msg structure. + * The function returns NULL if memory allocation has failed. + */ +static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) +{ + struct iucv_tty_buffer *bufp; + + bufp = mempool_alloc(hvc_iucv_mempool, flags); + if (!bufp) + return NULL; + memset(bufp, 0, sizeof(*bufp)); + + if (size > 0) { + bufp->msg.length = MSG_SIZE(size); + bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA); + if (!bufp->mbuf) { + mempool_free(bufp, hvc_iucv_mempool); + return NULL; + } + bufp->mbuf->version = MSG_VERSION; + bufp->mbuf->type = MSG_TYPE_DATA; + bufp->mbuf->datalen = (u16) size; + } + return bufp; +} + +/** + * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. + * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. + */ +static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) +{ + kfree(bufp->mbuf); + mempool_free(bufp, hvc_iucv_mempool); +} + +/** + * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. + * @list: List containing struct iucv_tty_buffer elements. + */ +static void destroy_tty_buffer_list(struct list_head *list) +{ + struct iucv_tty_buffer *ent, *next; + + list_for_each_entry_safe(ent, next, list, list) { + list_del(&ent->list); + destroy_tty_buffer(ent); + } +} + +/** + * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. + * @priv: Pointer to struct hvc_iucv_private + * @buf: HVC buffer for writing received terminal data. + * @count: HVC buffer size. + * @has_more_data: Pointer to an int variable. + * + * The function picks up pending messages from the input queue and receives + * the message data that is then written to the specified buffer @buf. + * If the buffer size @count is less than the data message size, the + * message is kept on the input queue and @has_more_data is set to 1. + * If all message data has been written, the message is removed from + * the input queue. + * + * The function returns the number of bytes written to the terminal, zero if + * there are no pending data messages available or if there is no established + * IUCV path. + * If the IUCV path has been severed, then -EPIPE is returned to cause a + * hang up (that is issued by the HVC layer). + */ +static int hvc_iucv_write(struct hvc_iucv_private *priv, + char *buf, int count, int *has_more_data) +{ + struct iucv_tty_buffer *rb; + int written; + int rc; + + /* immediately return if there is no IUCV connection */ + if (priv->iucv_state == IUCV_DISCONN) + return 0; + + /* if the IUCV path has been severed, return -EPIPE to inform the + * HVC layer to hang up the tty device. */ + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + /* check if there are pending messages */ + if (list_empty(&priv->tty_inqueue)) + return 0; + + /* receive an iucv message and flip data to the tty (ldisc) */ + rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); + + written = 0; + if (!rb->mbuf) { /* message not yet received ... */ + /* allocate mem to store msg data; if no memory is available + * then leave the buffer on the list and re-try later */ + rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA); + if (!rb->mbuf) + return -ENOMEM; + + rc = __iucv_message_receive(priv->path, &rb->msg, 0, + rb->mbuf, rb->msg.length, NULL); + switch (rc) { + case 0: /* Successful */ + break; + case 2: /* No message found */ + case 9: /* Message purged */ + break; + default: + written = -EIO; + } + /* remove buffer if an error has occurred or received data + * is not correct */ + if (rc || (rb->mbuf->version != MSG_VERSION) || + (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) + goto out_remove_buffer; + } + + switch (rb->mbuf->type) { + case MSG_TYPE_DATA: + written = min_t(int, rb->mbuf->datalen - rb->offset, count); + memcpy(buf, rb->mbuf->data + rb->offset, written); + if (written < (rb->mbuf->datalen - rb->offset)) { + rb->offset += written; + *has_more_data = 1; + goto out_written; + } + break; + + case MSG_TYPE_WINSIZE: + if (rb->mbuf->datalen != sizeof(struct winsize)) + break; + /* The caller must ensure that the hvc is locked, which + * is the case when called from hvc_iucv_get_chars() */ + __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data)); + break; + + case MSG_TYPE_ERROR: /* ignored ... */ + case MSG_TYPE_TERMENV: /* ignored ... */ + case MSG_TYPE_TERMIOS: /* ignored ... */ + break; + } + +out_remove_buffer: + list_del(&rb->list); + destroy_tty_buffer(rb); + *has_more_data = !list_empty(&priv->tty_inqueue); + +out_written: + return written; +} + +/** + * hvc_iucv_get_chars() - HVC get_chars operation. + * @vtermno: HVC virtual terminal number. + * @buf: Pointer to a buffer to store data + * @count: Size of buffer available for writing + * + * The HVC thread calls this method to read characters from the back-end. + * If an IUCV communication path has been established, pending IUCV messages + * are received and data is copied into buffer @buf up to @count bytes. + * + * Locking: The routine gets called under an irqsave() spinlock; and + * the routine locks the struct hvc_iucv_private->lock to call + * helper functions. + */ +static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) +{ + struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); + int written; + int has_more_data; + + if (count <= 0) + return 0; + + if (!priv) + return -ENODEV; + + spin_lock(&priv->lock); + has_more_data = 0; + written = hvc_iucv_write(priv, buf, count, &has_more_data); + spin_unlock(&priv->lock); + + /* if there are still messages on the queue... schedule another run */ + if (has_more_data) + hvc_kick(); + + return written; +} + +/** + * hvc_iucv_queue() - Buffer terminal data for sending. + * @priv: Pointer to struct hvc_iucv_private instance. + * @buf: Buffer containing data to send. + * @count: Size of buffer and amount of data to send. + * + * The function queues data for sending. To actually send the buffered data, + * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). + * The function returns the number of data bytes that has been buffered. + * + * If the device is not connected, data is ignored and the function returns + * @count. + * If the buffer is full, the function returns 0. + * If an existing IUCV communicaton path has been severed, -EPIPE is returned + * (that can be passed to HVC layer to cause a tty hangup). + */ +static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, + int count) +{ + size_t len; + + if (priv->iucv_state == IUCV_DISCONN) + return count; /* ignore data */ + + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); + if (!len) + return 0; + + memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); + priv->sndbuf_len += len; + + if (priv->iucv_state == IUCV_CONNECTED) + schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY); + + return len; +} + +/** + * hvc_iucv_send() - Send an IUCV message containing terminal data. + * @priv: Pointer to struct hvc_iucv_private instance. + * + * If an IUCV communication path has been established, the buffered output data + * is sent via an IUCV message and the number of bytes sent is returned. + * Returns 0 if there is no established IUCV communication path or + * -EPIPE if an existing IUCV communicaton path has been severed. + */ +static int hvc_iucv_send(struct hvc_iucv_private *priv) +{ + struct iucv_tty_buffer *sb; + int rc, len; + + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + if (priv->iucv_state == IUCV_DISCONN) + return -EIO; + + if (!priv->sndbuf_len) + return 0; + + /* allocate internal buffer to store msg data and also compute total + * message length */ + sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); + if (!sb) + return -ENOMEM; + + memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); + sb->mbuf->datalen = (u16) priv->sndbuf_len; + sb->msg.length = MSG_SIZE(sb->mbuf->datalen); + + list_add_tail(&sb->list, &priv->tty_outqueue); + + rc = __iucv_message_send(priv->path, &sb->msg, 0, 0, + (void *) sb->mbuf, sb->msg.length); + if (rc) { + /* drop the message here; however we might want to handle + * 0x03 (msg limit reached) by trying again... */ + list_del(&sb->list); + destroy_tty_buffer(sb); + } + len = priv->sndbuf_len; + priv->sndbuf_len = 0; + + return len; +} + +/** + * hvc_iucv_sndbuf_work() - Send buffered data over IUCV + * @work: Work structure. + * + * This work queue function sends buffered output data over IUCV and, + * if not all buffered data could be sent, reschedules itself. + */ +static void hvc_iucv_sndbuf_work(struct work_struct *work) +{ + struct hvc_iucv_private *priv; + + priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); + + spin_lock_bh(&priv->lock); + hvc_iucv_send(priv); + spin_unlock_bh(&priv->lock); +} + +/** + * hvc_iucv_put_chars() - HVC put_chars operation. + * @vtermno: HVC virtual terminal number. + * @buf: Pointer to an buffer to read data from + * @count: Size of buffer available for reading + * + * The HVC thread calls this method to write characters to the back-end. + * The function calls hvc_iucv_queue() to queue terminal data for sending. + * + * Locking: The method gets called under an irqsave() spinlock; and + * locks struct hvc_iucv_private->lock. + */ +static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) +{ + struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); + int queued; + + if (count <= 0) + return 0; + + if (!priv) + return -ENODEV; + + spin_lock(&priv->lock); + queued = hvc_iucv_queue(priv, buf, count); + spin_unlock(&priv->lock); + + return queued; +} + +/** + * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. + * @hp: Pointer to the HVC device (struct hvc_struct) + * @id: Additional data (originally passed to hvc_alloc): the index of an struct + * hvc_iucv_private instance. + * + * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private + * instance that is derived from @id. Always returns 0. + * + * Locking: struct hvc_iucv_private->lock, spin_lock_bh + */ +static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + + priv = hvc_iucv_get_private(id); + if (!priv) + return 0; + + spin_lock_bh(&priv->lock); + priv->tty_state = TTY_OPENED; + spin_unlock_bh(&priv->lock); + + return 0; +} + +/** + * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. + * @priv: Pointer to the struct hvc_iucv_private instance. + */ +static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) +{ + destroy_tty_buffer_list(&priv->tty_outqueue); + destroy_tty_buffer_list(&priv->tty_inqueue); + + priv->tty_state = TTY_CLOSED; + priv->iucv_state = IUCV_DISCONN; + + priv->sndbuf_len = 0; +} + +/** + * tty_outqueue_empty() - Test if the tty outq is empty + * @priv: Pointer to struct hvc_iucv_private instance. + */ +static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) +{ + int rc; + + spin_lock_bh(&priv->lock); + rc = list_empty(&priv->tty_outqueue); + spin_unlock_bh(&priv->lock); + + return rc; +} + +/** + * flush_sndbuf_sync() - Flush send buffer and wait for completion + * @priv: Pointer to struct hvc_iucv_private instance. + * + * The routine cancels a pending sndbuf work, calls hvc_iucv_send() + * to flush any buffered terminal output data and waits for completion. + */ +static void flush_sndbuf_sync(struct hvc_iucv_private *priv) +{ + int sync_wait; + + cancel_delayed_work_sync(&priv->sndbuf_work); + + spin_lock_bh(&priv->lock); + hvc_iucv_send(priv); /* force sending buffered data */ + sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */ + spin_unlock_bh(&priv->lock); + + if (sync_wait) + wait_event_timeout(priv->sndbuf_waitq, + tty_outqueue_empty(priv), HZ/10); +} + +/** + * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up + * @priv: Pointer to hvc_iucv_private structure + * + * This routine severs an existing IUCV communication path and hangs + * up the underlying HVC terminal device. + * The hang-up occurs only if an IUCV communication path is established; + * otherwise there is no need to hang up the terminal device. + * + * The IUCV HVC hang-up is separated into two steps: + * 1. After the IUCV path has been severed, the iucv_state is set to + * IUCV_SEVERED. + * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the + * IUCV_SEVERED state causes the tty hang-up in the HVC layer. + * + * If the tty has not yet been opened, clean up the hvc_iucv_private + * structure to allow re-connects. + * If the tty has been opened, let get_chars() return -EPIPE to signal + * the HVC layer to hang up the tty and, if so, wake up the HVC thread + * to call get_chars()... + * + * Special notes on hanging up a HVC terminal instantiated as console: + * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops) + * 2. do_tty_hangup() calls tty->ops->close() for console_filp + * => no hangup notifier is called by HVC (default) + * 2. hvc_close() returns because of tty_hung_up_p(filp) + * => no delete notifier is called! + * Finally, the back-end is not being notified, thus, the tty session is + * kept active (TTY_OPEN) to be ready for re-connects. + * + * Locking: spin_lock(&priv->lock) w/o disabling bh + */ +static void hvc_iucv_hangup(struct hvc_iucv_private *priv) +{ + struct iucv_path *path; + + path = NULL; + spin_lock(&priv->lock); + if (priv->iucv_state == IUCV_CONNECTED) { + path = priv->path; + priv->path = NULL; + priv->iucv_state = IUCV_SEVERED; + if (priv->tty_state == TTY_CLOSED) + hvc_iucv_cleanup(priv); + else + /* console is special (see above) */ + if (priv->is_console) { + hvc_iucv_cleanup(priv); + priv->tty_state = TTY_OPENED; + } else + hvc_kick(); + } + spin_unlock(&priv->lock); + + /* finally sever path (outside of priv->lock due to lock ordering) */ + if (path) { + iucv_path_sever(path, NULL); + iucv_path_free(path); + } +} + +/** + * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. + * @hp: Pointer to the HVC device (struct hvc_struct) + * @id: Additional data (originally passed to hvc_alloc): + * the index of an struct hvc_iucv_private instance. + * + * This routine notifies the HVC back-end that a tty hangup (carrier loss, + * virtual or otherwise) has occurred. + * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) + * to keep an existing IUCV communication path established. + * (Background: vhangup() is called from user space (by getty or login) to + * disable writing to the tty by other applications). + * If the tty has been opened and an established IUCV path has been severed + * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + + priv = hvc_iucv_get_private(id); + if (!priv) + return; + + flush_sndbuf_sync(priv); + + spin_lock_bh(&priv->lock); + /* NOTE: If the hangup was scheduled by ourself (from the iucv + * path_servered callback [IUCV_SEVERED]), we have to clean up + * our structure and to set state to TTY_CLOSED. + * If the tty was hung up otherwise (e.g. vhangup()), then we + * ignore this hangup and keep an established IUCV path open... + * (...the reason is that we are not able to connect back to the + * client if we disconnect on hang up) */ + priv->tty_state = TTY_CLOSED; + + if (priv->iucv_state == IUCV_SEVERED) + hvc_iucv_cleanup(priv); + spin_unlock_bh(&priv->lock); +} + +/** + * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS + * @hp: Pointer the HVC device (struct hvc_struct) + * @raise: Non-zero to raise or zero to lower DTR/RTS lines + * + * This routine notifies the HVC back-end to raise or lower DTR/RTS + * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to + * drop the IUCV connection (similar to hang up the modem). + */ +static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise) +{ + struct hvc_iucv_private *priv; + struct iucv_path *path; + + /* Raising the DTR/RTS is ignored as IUCV connections can be + * established at any times. + */ + if (raise) + return; + + priv = hvc_iucv_get_private(hp->vtermno); + if (!priv) + return; + + /* Lowering the DTR/RTS lines disconnects an established IUCV + * connection. + */ + flush_sndbuf_sync(priv); + + spin_lock_bh(&priv->lock); + path = priv->path; /* save reference to IUCV path */ + priv->path = NULL; + priv->iucv_state = IUCV_DISCONN; + spin_unlock_bh(&priv->lock); + + /* Sever IUCV path outside of priv->lock due to lock ordering of: + * priv->lock <--> iucv_table_lock */ + if (path) { + iucv_path_sever(path, NULL); + iucv_path_free(path); + } +} + +/** + * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. + * @hp: Pointer to the HVC device (struct hvc_struct) + * @id: Additional data (originally passed to hvc_alloc): + * the index of an struct hvc_iucv_private instance. + * + * This routine notifies the HVC back-end that the last tty device fd has been + * closed. The function cleans up tty resources. The clean-up of the IUCV + * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios + * control setting. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + + priv = hvc_iucv_get_private(id); + if (!priv) + return; + + flush_sndbuf_sync(priv); + + spin_lock_bh(&priv->lock); + destroy_tty_buffer_list(&priv->tty_outqueue); + destroy_tty_buffer_list(&priv->tty_inqueue); + priv->tty_state = TTY_CLOSED; + priv->sndbuf_len = 0; + spin_unlock_bh(&priv->lock); +} + +/** + * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID + * @ipvmid: Originating z/VM user ID (right padded with blanks) + * + * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to + * connect, otherwise non-zero. + */ +static int hvc_iucv_filter_connreq(u8 ipvmid[8]) +{ + const char *wildcard, *filter_entry; + size_t i, len; + + /* Note: default policy is ACCEPT if no filter is set */ + if (!hvc_iucv_filter_size) + return 0; + + for (i = 0; i < hvc_iucv_filter_size; i++) { + filter_entry = hvc_iucv_filter + (8 * i); + + /* If a filter entry contains the filter wildcard character, + * reduce the length to match the leading portion of the user + * ID only (wildcard match). Characters following the wildcard + * are ignored. + */ + wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR); + len = (wildcard) ? wildcard - filter_entry : 8; + if (0 == memcmp(ipvmid, filter_entry, len)) + return 0; + } + return 1; +} + +/** + * hvc_iucv_path_pending() - IUCV handler to process a connection request. + * @path: Pending path (struct iucv_path) + * @ipvmid: z/VM system identifier of originator + * @ipuser: User specified data for this path + * (AF_IUCV: port/service name and originator port) + * + * The function uses the @ipuser data to determine if the pending path belongs + * to a terminal managed by this device driver. + * If the path belongs to this driver, ensure that the terminal is not accessed + * multiple times (only one connection to a terminal is allowed). + * If the terminal is not yet connected, the pending path is accepted and is + * associated to the appropriate struct hvc_iucv_private instance. + * + * Returns 0 if @path belongs to a terminal managed by the this device driver; + * otherwise returns -ENODEV in order to dispatch this path to other handlers. + * + * Locking: struct hvc_iucv_private->lock + */ +static int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid, + u8 *ipuser) +{ + struct hvc_iucv_private *priv, *tmp; + u8 wildcard[9] = "lnxhvc "; + int i, rc, find_unused; + u8 nuser_data[16]; + u8 vm_user_id[9]; + + ASCEBC(wildcard, sizeof(wildcard)); + find_unused = !memcmp(wildcard, ipuser, 8); + + /* First, check if the pending path request is managed by this + * IUCV handler: + * - find a disconnected device if ipuser contains the wildcard + * - find the device that matches the terminal ID in ipuser + */ + priv = NULL; + for (i = 0; i < hvc_iucv_devices; i++) { + tmp = hvc_iucv_table[i]; + if (!tmp) + continue; + + if (find_unused) { + spin_lock(&tmp->lock); + if (tmp->iucv_state == IUCV_DISCONN) + priv = tmp; + spin_unlock(&tmp->lock); + + } else if (!memcmp(tmp->srv_name, ipuser, 8)) + priv = tmp; + if (priv) + break; + } + if (!priv) + return -ENODEV; + + /* Enforce that ipvmid is allowed to connect to us */ + read_lock(&hvc_iucv_filter_lock); + rc = hvc_iucv_filter_connreq(ipvmid); + read_unlock(&hvc_iucv_filter_lock); + if (rc) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + memcpy(vm_user_id, ipvmid, 8); + vm_user_id[8] = 0; + pr_info("A connection request from z/VM user ID %s " + "was refused\n", vm_user_id); + return 0; + } + + spin_lock(&priv->lock); + + /* If the terminal is already connected or being severed, then sever + * this path to enforce that there is only ONE established communication + * path per terminal. */ + if (priv->iucv_state != IUCV_DISCONN) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + goto out_path_handled; + } + + /* accept path */ + memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ + memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ + path->msglim = 0xffff; /* IUCV MSGLIMIT */ + path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ + rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); + if (rc) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + goto out_path_handled; + } + priv->path = path; + priv->iucv_state = IUCV_CONNECTED; + + /* store path information */ + memcpy(priv->info_path, ipvmid, 8); + memcpy(priv->info_path + 8, ipuser + 8, 8); + + /* flush buffered output data... */ + schedule_delayed_work(&priv->sndbuf_work, 5); + +out_path_handled: + spin_unlock(&priv->lock); + return 0; +} + +/** + * hvc_iucv_path_severed() - IUCV handler to process a path sever. + * @path: Pending path (struct iucv_path) + * @ipuser: User specified data for this path + * (AF_IUCV: port/service name and originator port) + * + * This function calls the hvc_iucv_hangup() function for the + * respective IUCV HVC terminal. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser) +{ + struct hvc_iucv_private *priv = path->private; + + hvc_iucv_hangup(priv); +} + +/** + * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. + * @path: Pending path (struct iucv_path) + * @msg: Pointer to the IUCV message + * + * The function puts an incoming message on the input queue for later + * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). + * If the tty has not yet been opened, the message is rejected. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_msg_pending(struct iucv_path *path, + struct iucv_message *msg) +{ + struct hvc_iucv_private *priv = path->private; + struct iucv_tty_buffer *rb; + + /* reject messages that exceed max size of iucv_tty_msg->datalen */ + if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { + iucv_message_reject(path, msg); + return; + } + + spin_lock(&priv->lock); + + /* reject messages if tty has not yet been opened */ + if (priv->tty_state == TTY_CLOSED) { + iucv_message_reject(path, msg); + goto unlock_return; + } + + /* allocate tty buffer to save iucv msg only */ + rb = alloc_tty_buffer(0, GFP_ATOMIC); + if (!rb) { + iucv_message_reject(path, msg); + goto unlock_return; /* -ENOMEM */ + } + rb->msg = *msg; + + list_add_tail(&rb->list, &priv->tty_inqueue); + + hvc_kick(); /* wake up hvc thread */ + +unlock_return: + spin_unlock(&priv->lock); +} + +/** + * hvc_iucv_msg_complete() - IUCV handler to process message completion + * @path: Pending path (struct iucv_path) + * @msg: Pointer to the IUCV message + * + * The function is called upon completion of message delivery to remove the + * message from the outqueue. Additional delivery information can be found + * msg->audit: rejected messages (0x040000 (IPADRJCT)), and + * purged messages (0x010000 (IPADPGNR)). + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_msg_complete(struct iucv_path *path, + struct iucv_message *msg) +{ + struct hvc_iucv_private *priv = path->private; + struct iucv_tty_buffer *ent, *next; + LIST_HEAD(list_remove); + + spin_lock(&priv->lock); + list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) + if (ent->msg.id == msg->id) { + list_move(&ent->list, &list_remove); + break; + } + wake_up(&priv->sndbuf_waitq); + spin_unlock(&priv->lock); + destroy_tty_buffer_list(&list_remove); +} + +static ssize_t hvc_iucv_dev_termid_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct hvc_iucv_private *priv = dev_get_drvdata(dev); + size_t len; + + len = sizeof(priv->srv_name); + memcpy(buf, priv->srv_name, len); + EBCASC(buf, len); + buf[len++] = '\n'; + return len; +} + +static ssize_t hvc_iucv_dev_state_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct hvc_iucv_private *priv = dev_get_drvdata(dev); + return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state); +} + +static ssize_t hvc_iucv_dev_peer_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct hvc_iucv_private *priv = dev_get_drvdata(dev); + char vmid[9], ipuser[9]; + + memset(vmid, 0, sizeof(vmid)); + memset(ipuser, 0, sizeof(ipuser)); + + spin_lock_bh(&priv->lock); + if (priv->iucv_state == IUCV_CONNECTED) { + memcpy(vmid, priv->info_path, 8); + memcpy(ipuser, priv->info_path + 8, 8); + } + spin_unlock_bh(&priv->lock); + EBCASC(ipuser, 8); + + return sprintf(buf, "%s:%s\n", vmid, ipuser); +} + + +/* HVC operations */ +static const struct hv_ops hvc_iucv_ops = { + .get_chars = hvc_iucv_get_chars, + .put_chars = hvc_iucv_put_chars, + .notifier_add = hvc_iucv_notifier_add, + .notifier_del = hvc_iucv_notifier_del, + .notifier_hangup = hvc_iucv_notifier_hangup, + .dtr_rts = hvc_iucv_dtr_rts, +}; + +/* IUCV HVC device attributes */ +static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL); +static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL); +static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL); +static struct attribute *hvc_iucv_dev_attrs[] = { + &dev_attr_termid.attr, + &dev_attr_state.attr, + &dev_attr_peer.attr, + NULL, +}; +static struct attribute_group hvc_iucv_dev_attr_group = { + .attrs = hvc_iucv_dev_attrs, +}; +static const struct attribute_group *hvc_iucv_dev_attr_groups[] = { + &hvc_iucv_dev_attr_group, + NULL, +}; + + +/** + * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance + * @id: hvc_iucv_table index + * @is_console: Flag if the instance is used as Linux console + * + * This function allocates a new hvc_iucv_private structure and stores + * the instance in hvc_iucv_table at index @id. + * Returns 0 on success; otherwise non-zero. + */ +static int __init hvc_iucv_alloc(int id, unsigned int is_console) +{ + struct hvc_iucv_private *priv; + char name[9]; + int rc; + + priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + spin_lock_init(&priv->lock); + INIT_LIST_HEAD(&priv->tty_outqueue); + INIT_LIST_HEAD(&priv->tty_inqueue); + INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); + init_waitqueue_head(&priv->sndbuf_waitq); + + priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); + if (!priv->sndbuf) { + kfree(priv); + return -ENOMEM; + } + + /* set console flag */ + priv->is_console = is_console; + + /* allocate hvc device */ + priv->hvc = hvc_alloc(id, /* PAGE_SIZE */ + id, &hvc_iucv_ops, 256); + if (IS_ERR(priv->hvc)) { + rc = PTR_ERR(priv->hvc); + goto out_error_hvc; + } + + /* notify HVC thread instead of using polling */ + priv->hvc->irq_requested = 1; + + /* setup iucv related information */ + snprintf(name, 9, "lnxhvc%-2d", id); + memcpy(priv->srv_name, name, 8); + ASCEBC(priv->srv_name, 8); + + /* create and setup device */ + priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL); + if (!priv->dev) { + rc = -ENOMEM; + goto out_error_dev; + } + dev_set_name(priv->dev, "hvc_iucv%d", id); + dev_set_drvdata(priv->dev, priv); + priv->dev->bus = &iucv_bus; + priv->dev->parent = iucv_root; + priv->dev->groups = hvc_iucv_dev_attr_groups; + priv->dev->release = (void (*)(struct device *)) kfree; + rc = device_register(priv->dev); + if (rc) { + put_device(priv->dev); + goto out_error_dev; + } + + hvc_iucv_table[id] = priv; + return 0; + +out_error_dev: + hvc_remove(priv->hvc); +out_error_hvc: + free_page((unsigned long) priv->sndbuf); + kfree(priv); + + return rc; +} + +/** + * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances + */ +static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) +{ + hvc_remove(priv->hvc); + device_unregister(priv->dev); + free_page((unsigned long) priv->sndbuf); + kfree(priv); +} + +/** + * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID + * @filter: String containing a comma-separated list of z/VM user IDs + * @dest: Location where to store the parsed z/VM user ID + */ +static const char *hvc_iucv_parse_filter(const char *filter, char *dest) +{ + const char *nextdelim, *residual; + size_t len; + + nextdelim = strchr(filter, ','); + if (nextdelim) { + len = nextdelim - filter; + residual = nextdelim + 1; + } else { + len = strlen(filter); + residual = filter + len; + } + + if (len == 0) + return ERR_PTR(-EINVAL); + + /* check for '\n' (if called from sysfs) */ + if (filter[len - 1] == '\n') + len--; + + /* prohibit filter entries containing the wildcard character only */ + if (len == 1 && *filter == FILTER_WILDCARD_CHAR) + return ERR_PTR(-EINVAL); + + if (len > 8) + return ERR_PTR(-EINVAL); + + /* pad with blanks and save upper case version of user ID */ + memset(dest, ' ', 8); + while (len--) + dest[len] = toupper(filter[len]); + return residual; +} + +/** + * hvc_iucv_setup_filter() - Set up z/VM user ID filter + * @filter: String consisting of a comma-separated list of z/VM user IDs + * + * The function parses the @filter string and creates an array containing + * the list of z/VM user ID filter entries. + * Return code 0 means success, -EINVAL if the filter is syntactically + * incorrect, -ENOMEM if there was not enough memory to allocate the + * filter list array, or -ENOSPC if too many z/VM user IDs have been specified. + */ +static int hvc_iucv_setup_filter(const char *val) +{ + const char *residual; + int err; + size_t size, count; + void *array, *old_filter; + + count = strlen(val); + if (count == 0 || (count == 1 && val[0] == '\n')) { + size = 0; + array = NULL; + goto out_replace_filter; /* clear filter */ + } + + /* count user IDs in order to allocate sufficient memory */ + size = 1; + residual = val; + while ((residual = strchr(residual, ',')) != NULL) { + residual++; + size++; + } + + /* check if the specified list exceeds the filter limit */ + if (size > MAX_VMID_FILTER) + return -ENOSPC; + + array = kcalloc(size, 8, GFP_KERNEL); + if (!array) + return -ENOMEM; + + count = size; + residual = val; + while (*residual && count) { + residual = hvc_iucv_parse_filter(residual, + array + ((size - count) * 8)); + if (IS_ERR(residual)) { + err = PTR_ERR(residual); + kfree(array); + goto out_err; + } + count--; + } + +out_replace_filter: + write_lock_bh(&hvc_iucv_filter_lock); + old_filter = hvc_iucv_filter; + hvc_iucv_filter_size = size; + hvc_iucv_filter = array; + write_unlock_bh(&hvc_iucv_filter_lock); + kfree(old_filter); + + err = 0; +out_err: + return err; +} + +/** + * param_set_vmidfilter() - Set z/VM user ID filter parameter + * @val: String consisting of a comma-separated list of z/VM user IDs + * @kp: Kernel parameter pointing to hvc_iucv_filter array + * + * The function sets up the z/VM user ID filter specified as comma-separated + * list of user IDs in @val. + * Note: If it is called early in the boot process, @val is stored and + * parsed later in hvc_iucv_init(). + */ +static int param_set_vmidfilter(const char *val, const struct kernel_param *kp) +{ + int rc; + + if (!MACHINE_IS_VM || !hvc_iucv_devices) + return -ENODEV; + + if (!val) + return -EINVAL; + + rc = 0; + if (slab_is_available()) + rc = hvc_iucv_setup_filter(val); + else + hvc_iucv_filter_string = val; /* defer... */ + return rc; +} + +/** + * param_get_vmidfilter() - Get z/VM user ID filter + * @buffer: Buffer to store z/VM user ID filter, + * (buffer size assumption PAGE_SIZE) + * @kp: Kernel parameter pointing to the hvc_iucv_filter array + * + * The function stores the filter as a comma-separated list of z/VM user IDs + * in @buffer. Typically, sysfs routines call this function for attr show. + */ +static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp) +{ + int rc; + size_t index, len; + void *start, *end; + + if (!MACHINE_IS_VM || !hvc_iucv_devices) + return -ENODEV; + + rc = 0; + read_lock_bh(&hvc_iucv_filter_lock); + for (index = 0; index < hvc_iucv_filter_size; index++) { + start = hvc_iucv_filter + (8 * index); + end = memchr(start, ' ', 8); + len = (end) ? end - start : 8; + memcpy(buffer + rc, start, len); + rc += len; + buffer[rc++] = ','; + } + read_unlock_bh(&hvc_iucv_filter_lock); + if (rc) + buffer[--rc] = '\0'; /* replace last comma and update rc */ + return rc; +} + +#define param_check_vmidfilter(name, p) __param_check(name, p, void) + +static const struct kernel_param_ops param_ops_vmidfilter = { + .set = param_set_vmidfilter, + .get = param_get_vmidfilter, +}; + +/** + * hvc_iucv_init() - z/VM IUCV HVC device driver initialization + */ +static int __init hvc_iucv_init(void) +{ + int rc; + unsigned int i; + + if (!hvc_iucv_devices) + return -ENODEV; + + if (!MACHINE_IS_VM) { + pr_notice("The z/VM IUCV HVC device driver cannot " + "be used without z/VM\n"); + rc = -ENODEV; + goto out_error; + } + + if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) { + pr_err("%lu is not a valid value for the hvc_iucv= " + "kernel parameter\n", hvc_iucv_devices); + rc = -EINVAL; + goto out_error; + } + + /* parse hvc_iucv_allow string and create z/VM user ID filter list */ + if (hvc_iucv_filter_string) { + rc = hvc_iucv_setup_filter(hvc_iucv_filter_string); + switch (rc) { + case 0: + break; + case -ENOMEM: + pr_err("Allocating memory failed with " + "reason code=%d\n", 3); + goto out_error; + case -EINVAL: + pr_err("hvc_iucv_allow= does not specify a valid " + "z/VM user ID list\n"); + goto out_error; + case -ENOSPC: + pr_err("hvc_iucv_allow= specifies too many " + "z/VM user IDs\n"); + goto out_error; + default: + goto out_error; + } + } + + hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, + sizeof(struct iucv_tty_buffer), + 0, 0, NULL); + if (!hvc_iucv_buffer_cache) { + pr_err("Allocating memory failed with reason code=%d\n", 1); + rc = -ENOMEM; + goto out_error; + } + + hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, + hvc_iucv_buffer_cache); + if (!hvc_iucv_mempool) { + pr_err("Allocating memory failed with reason code=%d\n", 2); + kmem_cache_destroy(hvc_iucv_buffer_cache); + rc = -ENOMEM; + goto out_error; + } + + /* register the first terminal device as console + * (must be done before allocating hvc terminal devices) */ + rc = hvc_instantiate(0, IUCV_HVC_CON_IDX, &hvc_iucv_ops); + if (rc) { + pr_err("Registering HVC terminal device as " + "Linux console failed\n"); + goto out_error_memory; + } + + /* allocate hvc_iucv_private structs */ + for (i = 0; i < hvc_iucv_devices; i++) { + rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); + if (rc) { + pr_err("Creating a new HVC terminal device " + "failed with error code=%d\n", rc); + goto out_error_hvc; + } + } + + /* register IUCV callback handler */ + rc = iucv_register(&hvc_iucv_handler, 0); + if (rc) { + pr_err("Registering IUCV handlers failed with error code=%d\n", + rc); + goto out_error_hvc; + } + + return 0; + +out_error_hvc: + for (i = 0; i < hvc_iucv_devices; i++) + if (hvc_iucv_table[i]) + hvc_iucv_destroy(hvc_iucv_table[i]); +out_error_memory: + mempool_destroy(hvc_iucv_mempool); + kmem_cache_destroy(hvc_iucv_buffer_cache); +out_error: + kfree(hvc_iucv_filter); + hvc_iucv_devices = 0; /* ensure that we do not provide any device */ + return rc; +} + +/** + * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter + * @val: Parameter value (numeric) + */ +static int __init hvc_iucv_config(char *val) +{ + if (kstrtoul(val, 10, &hvc_iucv_devices)) + pr_warn("hvc_iucv= invalid parameter value '%s'\n", val); + return 1; +} + + +device_initcall(hvc_iucv_init); +__setup("hvc_iucv=", hvc_iucv_config); +core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c new file mode 100644 index 000000000..794c7b18a --- /dev/null +++ b/drivers/tty/hvc/hvc_opal.c @@ -0,0 +1,419 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * opal driver interface to hvc_console.c + * + * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. + */ + +#undef DEBUG + +#include <linux/types.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/console.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/export.h> +#include <linux/interrupt.h> + +#include <asm/hvconsole.h> +#include <asm/firmware.h> +#include <asm/hvsi.h> +#include <asm/udbg.h> +#include <asm/opal.h> + +#include "hvc_console.h" + +static const char hvc_opal_name[] = "hvc_opal"; + +static const struct of_device_id hvc_opal_match[] = { + { .name = "serial", .compatible = "ibm,opal-console-raw" }, + { .name = "serial", .compatible = "ibm,opal-console-hvsi" }, + { }, +}; + +typedef enum hv_protocol { + HV_PROTOCOL_RAW, + HV_PROTOCOL_HVSI +} hv_protocol_t; + +struct hvc_opal_priv { + hv_protocol_t proto; /* Raw data or HVSI packets */ + struct hvsi_priv hvsi; /* HVSI specific data */ +}; +static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES]; + +/* For early boot console */ +static struct hvc_opal_priv hvc_opal_boot_priv; +static u32 hvc_opal_boot_termno; + +static const struct hv_ops hvc_opal_raw_ops = { + .get_chars = opal_get_chars, + .put_chars = opal_put_chars, + .flush = opal_flush_chars, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count) +{ + struct hvc_opal_priv *pv = hvc_opal_privs[vtermno]; + + if (WARN_ON(!pv)) + return -ENODEV; + + return hvsilib_get_chars(&pv->hvsi, buf, count); +} + +static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count) +{ + struct hvc_opal_priv *pv = hvc_opal_privs[vtermno]; + + if (WARN_ON(!pv)) + return -ENODEV; + + return hvsilib_put_chars(&pv->hvsi, buf, count); +} + +static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data) +{ + struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno]; + int rc; + + pr_devel("HVSI@%x: do open !\n", hp->vtermno); + + rc = notifier_add_irq(hp, data); + if (rc) + return rc; + + return hvsilib_open(&pv->hvsi, hp); +} + +static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data) +{ + struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno]; + + pr_devel("HVSI@%x: do close !\n", hp->vtermno); + + hvsilib_close(&pv->hvsi, hp); + + notifier_del_irq(hp, data); +} + +static void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data) +{ + struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno]; + + pr_devel("HVSI@%x: do hangup !\n", hp->vtermno); + + hvsilib_close(&pv->hvsi, hp); + + notifier_hangup_irq(hp, data); +} + +static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp) +{ + struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno]; + + if (!pv) + return -EINVAL; + return pv->hvsi.mctrl; +} + +static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set, + unsigned int clear) +{ + struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno]; + + pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n", + hp->vtermno, set, clear); + + if (set & TIOCM_DTR) + hvsilib_write_mctrl(&pv->hvsi, 1); + else if (clear & TIOCM_DTR) + hvsilib_write_mctrl(&pv->hvsi, 0); + + return 0; +} + +static const struct hv_ops hvc_opal_hvsi_ops = { + .get_chars = hvc_opal_hvsi_get_chars, + .put_chars = hvc_opal_hvsi_put_chars, + .flush = opal_flush_chars, + .notifier_add = hvc_opal_hvsi_open, + .notifier_del = hvc_opal_hvsi_close, + .notifier_hangup = hvc_opal_hvsi_hangup, + .tiocmget = hvc_opal_hvsi_tiocmget, + .tiocmset = hvc_opal_hvsi_tiocmset, +}; + +static int hvc_opal_probe(struct platform_device *dev) +{ + const struct hv_ops *ops; + struct hvc_struct *hp; + struct hvc_opal_priv *pv; + hv_protocol_t proto; + unsigned int termno, irq, boot = 0; + const __be32 *reg; + + if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) { + proto = HV_PROTOCOL_RAW; + ops = &hvc_opal_raw_ops; + } else if (of_device_is_compatible(dev->dev.of_node, + "ibm,opal-console-hvsi")) { + proto = HV_PROTOCOL_HVSI; + ops = &hvc_opal_hvsi_ops; + } else { + pr_err("hvc_opal: Unknown protocol for %pOF\n", + dev->dev.of_node); + return -ENXIO; + } + + reg = of_get_property(dev->dev.of_node, "reg", NULL); + termno = reg ? be32_to_cpup(reg) : 0; + + /* Is it our boot one ? */ + if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) { + pv = hvc_opal_privs[termno]; + boot = 1; + } else if (hvc_opal_privs[termno] == NULL) { + pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL); + if (!pv) + return -ENOMEM; + pv->proto = proto; + hvc_opal_privs[termno] = pv; + if (proto == HV_PROTOCOL_HVSI) { + /* + * We want put_chars to be atomic to avoid mangling of + * hvsi packets. + */ + hvsilib_init(&pv->hvsi, + opal_get_chars, opal_put_chars_atomic, + termno, 0); + } + + /* Instanciate now to establish a mapping index==vtermno */ + hvc_instantiate(termno, termno, ops); + } else { + pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n", + dev->dev.of_node, termno); + return -ENXIO; + } + + pr_info("hvc%d: %s protocol on %pOF%s\n", termno, + proto == HV_PROTOCOL_RAW ? "raw" : "hvsi", + dev->dev.of_node, + boot ? " (boot console)" : ""); + + irq = irq_of_parse_and_map(dev->dev.of_node, 0); + if (!irq) { + pr_info("hvc%d: No interrupts property, using OPAL event\n", + termno); + irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT)); + } + + if (!irq) { + pr_err("hvc_opal: Unable to map interrupt for device %pOF\n", + dev->dev.of_node); + return irq; + } + + hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS); + if (IS_ERR(hp)) + return PTR_ERR(hp); + + /* hvc consoles on powernv may need to share a single irq */ + hp->flags = IRQF_SHARED; + dev_set_drvdata(&dev->dev, hp); + + return 0; +} + +static int hvc_opal_remove(struct platform_device *dev) +{ + struct hvc_struct *hp = dev_get_drvdata(&dev->dev); + int rc, termno; + + termno = hp->vtermno; + rc = hvc_remove(hp); + if (rc == 0) { + if (hvc_opal_privs[termno] != &hvc_opal_boot_priv) + kfree(hvc_opal_privs[termno]); + hvc_opal_privs[termno] = NULL; + } + return rc; +} + +static struct platform_driver hvc_opal_driver = { + .probe = hvc_opal_probe, + .remove = hvc_opal_remove, + .driver = { + .name = hvc_opal_name, + .of_match_table = hvc_opal_match, + } +}; + +static int __init hvc_opal_init(void) +{ + if (!firmware_has_feature(FW_FEATURE_OPAL)) + return -ENODEV; + + /* Register as a vio device to receive callbacks */ + return platform_driver_register(&hvc_opal_driver); +} +device_initcall(hvc_opal_init); + +static void udbg_opal_putc(char c) +{ + unsigned int termno = hvc_opal_boot_termno; + int count = -1; + + if (c == '\n') + udbg_opal_putc('\r'); + + do { + switch(hvc_opal_boot_priv.proto) { + case HV_PROTOCOL_RAW: + count = opal_put_chars(termno, &c, 1); + break; + case HV_PROTOCOL_HVSI: + count = hvc_opal_hvsi_put_chars(termno, &c, 1); + break; + } + + /* This is needed for the cosole to flush + * when there aren't any interrupts. + */ + opal_flush_console(termno); + } while(count == 0 || count == -EAGAIN); +} + +static int udbg_opal_getc_poll(void) +{ + unsigned int termno = hvc_opal_boot_termno; + int rc = 0; + char c; + + switch(hvc_opal_boot_priv.proto) { + case HV_PROTOCOL_RAW: + rc = opal_get_chars(termno, &c, 1); + break; + case HV_PROTOCOL_HVSI: + rc = hvc_opal_hvsi_get_chars(termno, &c, 1); + break; + } + if (!rc) + return -1; + return c; +} + +static int udbg_opal_getc(void) +{ + int ch; + for (;;) { + ch = udbg_opal_getc_poll(); + if (ch != -1) + return ch; + } +} + +static void udbg_init_opal_common(void) +{ + udbg_putc = udbg_opal_putc; + udbg_getc = udbg_opal_getc; + udbg_getc_poll = udbg_opal_getc_poll; +} + +void __init hvc_opal_init_early(void) +{ + struct device_node *stdout_node = of_node_get(of_stdout); + const __be32 *termno; + const struct hv_ops *ops; + u32 index; + + /* If the console wasn't in /chosen, try /ibm,opal */ + if (!stdout_node) { + struct device_node *opal, *np; + + /* Current OPAL takeover doesn't provide the stdout + * path, so we hard wire it + */ + opal = of_find_node_by_path("/ibm,opal/consoles"); + if (opal) { + pr_devel("hvc_opal: Found consoles in new location\n"); + } else { + opal = of_find_node_by_path("/ibm,opal"); + if (opal) + pr_devel("hvc_opal: " + "Found consoles in old location\n"); + } + if (!opal) + return; + for_each_child_of_node(opal, np) { + if (of_node_name_eq(np, "serial")) { + stdout_node = np; + break; + } + } + of_node_put(opal); + } + if (!stdout_node) + return; + termno = of_get_property(stdout_node, "reg", NULL); + index = termno ? be32_to_cpup(termno) : 0; + if (index >= MAX_NR_HVC_CONSOLES) + return; + hvc_opal_privs[index] = &hvc_opal_boot_priv; + + /* Check the protocol */ + if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) { + hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW; + ops = &hvc_opal_raw_ops; + pr_devel("hvc_opal: Found RAW console\n"); + } + else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) { + hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI; + ops = &hvc_opal_hvsi_ops; + hvsilib_init(&hvc_opal_boot_priv.hvsi, + opal_get_chars, opal_put_chars_atomic, + index, 1); + /* HVSI, perform the handshake now */ + hvsilib_establish(&hvc_opal_boot_priv.hvsi); + pr_devel("hvc_opal: Found HVSI console\n"); + } else + goto out; + hvc_opal_boot_termno = index; + udbg_init_opal_common(); + add_preferred_console("hvc", index, NULL); + hvc_instantiate(index, index, ops); +out: + of_node_put(stdout_node); +} + +#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW +void __init udbg_init_debug_opal_raw(void) +{ + u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO; + hvc_opal_privs[index] = &hvc_opal_boot_priv; + hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW; + hvc_opal_boot_termno = index; + udbg_init_opal_common(); +} +#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */ + +#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI +void __init udbg_init_debug_opal_hvsi(void) +{ + u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO; + hvc_opal_privs[index] = &hvc_opal_boot_priv; + hvc_opal_boot_termno = index; + udbg_init_opal_common(); + hvsilib_init(&hvc_opal_boot_priv.hvsi, + opal_get_chars, opal_put_chars_atomic, + index, 1); + hvsilib_establish(&hvc_opal_boot_priv.hvsi); +} +#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */ diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c new file mode 100644 index 000000000..31f53fa77 --- /dev/null +++ b/drivers/tty/hvc/hvc_riscv_sbi.c @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2008 David Gibson, IBM Corporation + * Copyright (C) 2012 Regents of the University of California + * Copyright (C) 2017 SiFive + */ + +#include <linux/console.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#include <asm/sbi.h> + +#include "hvc_console.h" + +static int hvc_sbi_tty_put(uint32_t vtermno, const char *buf, int count) +{ + int i; + + for (i = 0; i < count; i++) + sbi_console_putchar(buf[i]); + + return i; +} + +static int hvc_sbi_tty_get(uint32_t vtermno, char *buf, int count) +{ + int i, c; + + for (i = 0; i < count; i++) { + c = sbi_console_getchar(); + if (c < 0) + break; + buf[i] = c; + } + + return i; +} + +static const struct hv_ops hvc_sbi_ops = { + .get_chars = hvc_sbi_tty_get, + .put_chars = hvc_sbi_tty_put, +}; + +static int __init hvc_sbi_init(void) +{ + return PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_ops, 16)); +} +device_initcall(hvc_sbi_init); + +static int __init hvc_sbi_console_init(void) +{ + hvc_instantiate(0, 0, &hvc_sbi_ops); + + return 0; +} +console_initcall(hvc_sbi_console_init); diff --git a/drivers/tty/hvc/hvc_rtas.c b/drivers/tty/hvc/hvc_rtas.c new file mode 100644 index 000000000..e8b8c6454 --- /dev/null +++ b/drivers/tty/hvc/hvc_rtas.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * IBM RTAS driver interface to hvc_console.c + * + * (C) Copyright IBM Corporation 2001-2005 + * (C) Copyright Red Hat, Inc. 2005 + * + * Author(s): Maximino Augilar <IBM STI Design Center> + * : Ryan S. Arnold <rsa@us.ibm.com> + * : Utz Bacher <utz.bacher@de.ibm.com> + * : David Woodhouse <dwmw2@infradead.org> + * + * inspired by drivers/char/hvc_console.c + * written by Anton Blanchard and Paul Mackerras + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#include <asm/irq.h> +#include <asm/rtas.h> +#include "hvc_console.h" + +#define hvc_rtas_cookie 0x67781e15 +struct hvc_struct *hvc_rtas_dev; + +static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE; +static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE; + +static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf, + int count) +{ + int i; + + for (i = 0; i < count; i++) { + if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i])) + break; + } + + return i; +} + +static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count) +{ + int i, c; + + for (i = 0; i < count; i++) { + if (rtas_call(rtascons_get_char_token, 0, 2, &c)) + break; + + buf[i] = c; + } + + return i; +} + +static const struct hv_ops hvc_rtas_get_put_ops = { + .get_chars = hvc_rtas_read_console, + .put_chars = hvc_rtas_write_console, +}; + +static int __init hvc_rtas_init(void) +{ + struct hvc_struct *hp; + + if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) + rtascons_put_char_token = rtas_token("put-term-char"); + if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) + rtascons_get_char_token = rtas_token("get-term-char"); + if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + BUG_ON(hvc_rtas_dev); + + /* Allocate an hvc_struct for the console device we instantiated + * earlier. Save off hp so that we can return it on exit */ + hp = hvc_alloc(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops, 16); + if (IS_ERR(hp)) + return PTR_ERR(hp); + + hvc_rtas_dev = hp; + + return 0; +} +device_initcall(hvc_rtas_init); + +/* This will happen prior to module init. There is no tty at this time? */ +static int __init hvc_rtas_console_init(void) +{ + rtascons_put_char_token = rtas_token("put-term-char"); + if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + rtascons_get_char_token = rtas_token("get-term-char"); + if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops); + add_preferred_console("hvc", 0, NULL); + + return 0; +} +console_initcall(hvc_rtas_console_init); diff --git a/drivers/tty/hvc/hvc_udbg.c b/drivers/tty/hvc/hvc_udbg.c new file mode 100644 index 000000000..ff0dcc564 --- /dev/null +++ b/drivers/tty/hvc/hvc_udbg.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * udbg interface to hvc_console.c + * + * (C) Copyright David Gibson, IBM Corporation 2008. + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/irq.h> + +#include <asm/udbg.h> + +#include "hvc_console.h" + +static struct hvc_struct *hvc_udbg_dev; + +static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count) +{ + int i; + + for (i = 0; i < count && udbg_putc; i++) + udbg_putc(buf[i]); + + return i; +} + +static int hvc_udbg_get(uint32_t vtermno, char *buf, int count) +{ + int i, c; + + if (!udbg_getc_poll) + return 0; + + for (i = 0; i < count; i++) { + if ((c = udbg_getc_poll()) == -1) + break; + buf[i] = c; + } + + return i; +} + +static const struct hv_ops hvc_udbg_ops = { + .get_chars = hvc_udbg_get, + .put_chars = hvc_udbg_put, +}; + +static int __init hvc_udbg_init(void) +{ + struct hvc_struct *hp; + + if (!udbg_putc) + return -ENODEV; + + BUG_ON(hvc_udbg_dev); + + hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16); + if (IS_ERR(hp)) + return PTR_ERR(hp); + + hvc_udbg_dev = hp; + + return 0; +} +device_initcall(hvc_udbg_init); + +static int __init hvc_udbg_console_init(void) +{ + if (!udbg_putc) + return -ENODEV; + + hvc_instantiate(0, 0, &hvc_udbg_ops); + add_preferred_console("hvc", 0, NULL); + + return 0; +} +console_initcall(hvc_udbg_console_init); diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c new file mode 100644 index 000000000..736b230f5 --- /dev/null +++ b/drivers/tty/hvc/hvc_vio.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * vio driver interface to hvc_console.c + * + * This code was moved here to allow the remaining code to be reused as a + * generic polling mode with semi-reliable transport driver core to the + * console and tty subsystems. + * + * + * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM + * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM + * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. + * Copyright (C) 2004 IBM Corporation + * + * Additional Author(s): + * Ryan S. Arnold <rsa@us.ibm.com> + * + * TODO: + * + * - handle error in sending hvsi protocol packets + * - retry nego on subsequent sends ? + */ + +#undef DEBUG + +#include <linux/types.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/console.h> +#include <linux/of.h> + +#include <asm/hvconsole.h> +#include <asm/vio.h> +#include <asm/hvsi.h> +#include <asm/udbg.h> +#include <asm/machdep.h> + +#include "hvc_console.h" + +static const char hvc_driver_name[] = "hvc_console"; + +static const struct vio_device_id hvc_driver_table[] = { + {"serial", "hvterm1"}, +#ifndef HVC_OLD_HVSI + {"serial", "hvterm-protocol"}, +#endif + { "", "" } +}; + +typedef enum hv_protocol { + HV_PROTOCOL_RAW, + HV_PROTOCOL_HVSI +} hv_protocol_t; + +struct hvterm_priv { + u32 termno; /* HV term number */ + hv_protocol_t proto; /* Raw data or HVSI packets */ + struct hvsi_priv hvsi; /* HVSI specific data */ + spinlock_t buf_lock; + char buf[SIZE_VIO_GET_CHARS]; + int left; + int offset; +}; +static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES]; +/* For early boot console */ +static struct hvterm_priv hvterm_priv0; + +static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count) +{ + struct hvterm_priv *pv = hvterm_privs[vtermno]; + unsigned long i; + unsigned long flags; + int got; + + if (WARN_ON(!pv)) + return 0; + + spin_lock_irqsave(&pv->buf_lock, flags); + + if (pv->left == 0) { + pv->offset = 0; + pv->left = hvc_get_chars(pv->termno, pv->buf, count); + + /* + * Work around a HV bug where it gives us a null + * after every \r. -- paulus + */ + for (i = 1; i < pv->left; ++i) { + if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') { + --pv->left; + if (i < pv->left) { + memmove(&pv->buf[i], &pv->buf[i+1], + pv->left - i); + } + } + } + } + + got = min(count, pv->left); + memcpy(buf, &pv->buf[pv->offset], got); + pv->offset += got; + pv->left -= got; + + spin_unlock_irqrestore(&pv->buf_lock, flags); + + return got; +} + +/** + * hvterm_raw_put_chars: send characters to firmware for given vterm adapter + * @vtermno: The virtual terminal number. + * @buf: The characters to send. Because of the underlying hypercall in + * hvc_put_chars(), this buffer must be at least 16 bytes long, even if + * you are sending fewer chars. + * @count: number of chars to send. + */ +static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count) +{ + struct hvterm_priv *pv = hvterm_privs[vtermno]; + + if (WARN_ON(!pv)) + return 0; + + return hvc_put_chars(pv->termno, buf, count); +} + +static const struct hv_ops hvterm_raw_ops = { + .get_chars = hvterm_raw_get_chars, + .put_chars = hvterm_raw_put_chars, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count) +{ + struct hvterm_priv *pv = hvterm_privs[vtermno]; + + if (WARN_ON(!pv)) + return 0; + + return hvsilib_get_chars(&pv->hvsi, buf, count); +} + +static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count) +{ + struct hvterm_priv *pv = hvterm_privs[vtermno]; + + if (WARN_ON(!pv)) + return 0; + + return hvsilib_put_chars(&pv->hvsi, buf, count); +} + +static int hvterm_hvsi_open(struct hvc_struct *hp, int data) +{ + struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; + int rc; + + pr_devel("HVSI@%x: open !\n", pv->termno); + + rc = notifier_add_irq(hp, data); + if (rc) + return rc; + + return hvsilib_open(&pv->hvsi, hp); +} + +static void hvterm_hvsi_close(struct hvc_struct *hp, int data) +{ + struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; + + pr_devel("HVSI@%x: do close !\n", pv->termno); + + hvsilib_close(&pv->hvsi, hp); + + notifier_del_irq(hp, data); +} + +static void hvterm_hvsi_hangup(struct hvc_struct *hp, int data) +{ + struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; + + pr_devel("HVSI@%x: do hangup !\n", pv->termno); + + hvsilib_close(&pv->hvsi, hp); + + notifier_hangup_irq(hp, data); +} + +static int hvterm_hvsi_tiocmget(struct hvc_struct *hp) +{ + struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; + + if (!pv) + return -EINVAL; + return pv->hvsi.mctrl; +} + +static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set, + unsigned int clear) +{ + struct hvterm_priv *pv = hvterm_privs[hp->vtermno]; + + pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n", + pv->termno, set, clear); + + if (set & TIOCM_DTR) + hvsilib_write_mctrl(&pv->hvsi, 1); + else if (clear & TIOCM_DTR) + hvsilib_write_mctrl(&pv->hvsi, 0); + + return 0; +} + +static const struct hv_ops hvterm_hvsi_ops = { + .get_chars = hvterm_hvsi_get_chars, + .put_chars = hvterm_hvsi_put_chars, + .notifier_add = hvterm_hvsi_open, + .notifier_del = hvterm_hvsi_close, + .notifier_hangup = hvterm_hvsi_hangup, + .tiocmget = hvterm_hvsi_tiocmget, + .tiocmset = hvterm_hvsi_tiocmset, +}; + +static void udbg_hvc_putc(char c) +{ + int count = -1; + unsigned char bounce_buffer[16]; + + if (!hvterm_privs[0]) + return; + + if (c == '\n') + udbg_hvc_putc('\r'); + + do { + switch(hvterm_privs[0]->proto) { + case HV_PROTOCOL_RAW: + /* + * hvterm_raw_put_chars requires at least a 16-byte + * buffer, so go via the bounce buffer + */ + bounce_buffer[0] = c; + count = hvterm_raw_put_chars(0, bounce_buffer, 1); + break; + case HV_PROTOCOL_HVSI: + count = hvterm_hvsi_put_chars(0, &c, 1); + break; + } + } while (count == 0 || count == -EAGAIN); +} + +static int udbg_hvc_getc_poll(void) +{ + int rc = 0; + char c; + + if (!hvterm_privs[0]) + return -1; + + switch(hvterm_privs[0]->proto) { + case HV_PROTOCOL_RAW: + rc = hvterm_raw_get_chars(0, &c, 1); + break; + case HV_PROTOCOL_HVSI: + rc = hvterm_hvsi_get_chars(0, &c, 1); + break; + } + if (!rc) + return -1; + return c; +} + +static int udbg_hvc_getc(void) +{ + int ch; + + if (!hvterm_privs[0]) + return -1; + + for (;;) { + ch = udbg_hvc_getc_poll(); + if (ch == -1) { + /* This shouldn't be needed...but... */ + volatile unsigned long delay; + for (delay=0; delay < 2000000; delay++) + ; + } else { + return ch; + } + } +} + +static int hvc_vio_probe(struct vio_dev *vdev, + const struct vio_device_id *id) +{ + const struct hv_ops *ops; + struct hvc_struct *hp; + struct hvterm_priv *pv; + hv_protocol_t proto; + int i, termno = -1; + + /* probed with invalid parameters. */ + if (!vdev || !id) + return -EPERM; + + if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) { + proto = HV_PROTOCOL_RAW; + ops = &hvterm_raw_ops; + } else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) { + proto = HV_PROTOCOL_HVSI; + ops = &hvterm_hvsi_ops; + } else { + pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node); + return -ENXIO; + } + + pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n", + vdev->dev.of_node, + proto == HV_PROTOCOL_RAW ? "raw" : "hvsi"); + + /* Is it our boot one ? */ + if (hvterm_privs[0] == &hvterm_priv0 && + vdev->unit_address == hvterm_priv0.termno) { + pv = hvterm_privs[0]; + termno = 0; + pr_devel("->boot console, using termno 0\n"); + } + /* nope, allocate a new one */ + else { + for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++) + if (!hvterm_privs[i]) + termno = i; + pr_devel("->non-boot console, using termno %d\n", termno); + if (termno < 0) + return -ENODEV; + pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL); + if (!pv) + return -ENOMEM; + pv->termno = vdev->unit_address; + pv->proto = proto; + spin_lock_init(&pv->buf_lock); + hvterm_privs[termno] = pv; + hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars, + pv->termno, 0); + } + + hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS); + if (IS_ERR(hp)) + return PTR_ERR(hp); + dev_set_drvdata(&vdev->dev, hp); + + /* register udbg if it's not there already for console 0 */ + if (hp->index == 0 && !udbg_putc) { + udbg_putc = udbg_hvc_putc; + udbg_getc = udbg_hvc_getc; + udbg_getc_poll = udbg_hvc_getc_poll; + } + + return 0; +} + +static struct vio_driver hvc_vio_driver = { + .id_table = hvc_driver_table, + .probe = hvc_vio_probe, + .name = hvc_driver_name, + .driver = { + .suppress_bind_attrs = true, + }, +}; + +static int __init hvc_vio_init(void) +{ + int rc; + + /* Register as a vio device to receive callbacks */ + rc = vio_register_driver(&hvc_vio_driver); + + return rc; +} +device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */ + +void __init hvc_vio_init_early(void) +{ + const __be32 *termno; + const struct hv_ops *ops; + + /* find the boot console from /chosen/stdout */ + /* Check if it's a virtual terminal */ + if (!of_node_name_prefix(of_stdout, "vty")) + return; + termno = of_get_property(of_stdout, "reg", NULL); + if (termno == NULL) + return; + hvterm_priv0.termno = of_read_number(termno, 1); + spin_lock_init(&hvterm_priv0.buf_lock); + hvterm_privs[0] = &hvterm_priv0; + + /* Check the protocol */ + if (of_device_is_compatible(of_stdout, "hvterm1")) { + hvterm_priv0.proto = HV_PROTOCOL_RAW; + ops = &hvterm_raw_ops; + } + else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) { + hvterm_priv0.proto = HV_PROTOCOL_HVSI; + ops = &hvterm_hvsi_ops; + hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, + hvterm_priv0.termno, 1); + /* HVSI, perform the handshake now */ + hvsilib_establish(&hvterm_priv0.hvsi); + } else + return; + udbg_putc = udbg_hvc_putc; + udbg_getc = udbg_hvc_getc; + udbg_getc_poll = udbg_hvc_getc_poll; +#ifdef HVC_OLD_HVSI + /* When using the old HVSI driver don't register the HVC + * backend for HVSI, only do udbg + */ + if (hvterm_priv0.proto == HV_PROTOCOL_HVSI) + return; +#endif + /* Check whether the user has requested a different console. */ + if (!strstr(boot_command_line, "console=")) + add_preferred_console("hvc", 0, NULL); + hvc_instantiate(0, 0, ops); +} + +/* call this from early_init() for a working debug console on + * vterm capable LPAR machines + */ +#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR +void __init udbg_init_debug_lpar(void) +{ + /* + * If we're running as a hypervisor then we definitely can't call the + * hypervisor to print debug output (we *are* the hypervisor), so don't + * register if we detect that MSR_HV=1. + */ + if (mfmsr() & MSR_HV) + return; + + hvterm_privs[0] = &hvterm_priv0; + hvterm_priv0.termno = 0; + hvterm_priv0.proto = HV_PROTOCOL_RAW; + spin_lock_init(&hvterm_priv0.buf_lock); + udbg_putc = udbg_hvc_putc; + udbg_getc = udbg_hvc_getc; + udbg_getc_poll = udbg_hvc_getc_poll; +} +#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */ + +#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI +void __init udbg_init_debug_lpar_hvsi(void) +{ + /* See comment above in udbg_init_debug_lpar() */ + if (mfmsr() & MSR_HV) + return; + + hvterm_privs[0] = &hvterm_priv0; + hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO; + hvterm_priv0.proto = HV_PROTOCOL_HVSI; + spin_lock_init(&hvterm_priv0.buf_lock); + udbg_putc = udbg_hvc_putc; + udbg_getc = udbg_hvc_getc; + udbg_getc_poll = udbg_hvc_getc_poll; + hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars, + hvterm_priv0.termno, 1); + hvsilib_establish(&hvterm_priv0.hvsi); +} +#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */ diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c new file mode 100644 index 000000000..281bc83ac --- /dev/null +++ b/drivers/tty/hvc/hvc_xen.c @@ -0,0 +1,771 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * xen console driver interface to hvc_console.c + * + * (c) 2007 Gerd Hoffmann <kraxel@suse.de> + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/irq.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/serial_core.h> + +#include <asm/io.h> +#include <asm/xen/hypervisor.h> + +#include <xen/xen.h> +#include <xen/interface/xen.h> +#include <xen/hvm.h> +#include <xen/grant_table.h> +#include <xen/page.h> +#include <xen/events.h> +#include <xen/interface/io/console.h> +#include <xen/interface/sched.h> +#include <xen/hvc-console.h> +#include <xen/xenbus.h> + +#include "hvc_console.h" + +#define HVC_COOKIE 0x58656e /* "Xen" in hex */ + +struct xencons_info { + struct list_head list; + struct xenbus_device *xbdev; + struct xencons_interface *intf; + unsigned int evtchn; + XENCONS_RING_IDX out_cons; + unsigned int out_cons_same; + struct hvc_struct *hvc; + int irq; + int vtermno; + grant_ref_t gntref; + spinlock_t ring_lock; +}; + +static LIST_HEAD(xenconsoles); +static DEFINE_SPINLOCK(xencons_lock); + +/* ------------------------------------------------------------------ */ + +static struct xencons_info *vtermno_to_xencons(int vtermno) +{ + struct xencons_info *entry, *ret = NULL; + unsigned long flags; + + spin_lock_irqsave(&xencons_lock, flags); + if (list_empty(&xenconsoles)) { + spin_unlock_irqrestore(&xencons_lock, flags); + return NULL; + } + + list_for_each_entry(entry, &xenconsoles, list) { + if (entry->vtermno == vtermno) { + ret = entry; + break; + } + } + spin_unlock_irqrestore(&xencons_lock, flags); + + return ret; +} + +static inline int xenbus_devid_to_vtermno(int devid) +{ + return devid + HVC_COOKIE; +} + +static inline void notify_daemon(struct xencons_info *cons) +{ + /* Use evtchn: this is called early, before irq is set up. */ + notify_remote_via_evtchn(cons->evtchn); +} + +static int __write_console(struct xencons_info *xencons, + const char *data, int len) +{ + XENCONS_RING_IDX cons, prod; + struct xencons_interface *intf = xencons->intf; + int sent = 0; + unsigned long flags; + + spin_lock_irqsave(&xencons->ring_lock, flags); + cons = intf->out_cons; + prod = intf->out_prod; + mb(); /* update queue values before going on */ + + if ((prod - cons) > sizeof(intf->out)) { + spin_unlock_irqrestore(&xencons->ring_lock, flags); + pr_err_once("xencons: Illegal ring page indices"); + return -EINVAL; + } + + while ((sent < len) && ((prod - cons) < sizeof(intf->out))) + intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++]; + + wmb(); /* write ring before updating pointer */ + intf->out_prod = prod; + spin_unlock_irqrestore(&xencons->ring_lock, flags); + + if (sent) + notify_daemon(xencons); + return sent; +} + +static int domU_write_console(uint32_t vtermno, const char *data, int len) +{ + int ret = len; + struct xencons_info *cons = vtermno_to_xencons(vtermno); + if (cons == NULL) + return -EINVAL; + + /* + * Make sure the whole buffer is emitted, polling if + * necessary. We don't ever want to rely on the hvc daemon + * because the most interesting console output is when the + * kernel is crippled. + */ + while (len) { + int sent = __write_console(cons, data, len); + + if (sent < 0) + return sent; + + data += sent; + len -= sent; + + if (unlikely(len)) + HYPERVISOR_sched_op(SCHEDOP_yield, NULL); + } + + return ret; +} + +static int domU_read_console(uint32_t vtermno, char *buf, int len) +{ + struct xencons_interface *intf; + XENCONS_RING_IDX cons, prod; + int recv = 0; + struct xencons_info *xencons = vtermno_to_xencons(vtermno); + unsigned int eoiflag = 0; + unsigned long flags; + + if (xencons == NULL) + return -EINVAL; + intf = xencons->intf; + + spin_lock_irqsave(&xencons->ring_lock, flags); + cons = intf->in_cons; + prod = intf->in_prod; + mb(); /* get pointers before reading ring */ + + if ((prod - cons) > sizeof(intf->in)) { + spin_unlock_irqrestore(&xencons->ring_lock, flags); + pr_err_once("xencons: Illegal ring page indices"); + return -EINVAL; + } + + while (cons != prod && recv < len) + buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)]; + + mb(); /* read ring before consuming */ + intf->in_cons = cons; + + /* + * When to mark interrupt having been spurious: + * - there was no new data to be read, and + * - the backend did not consume some output bytes, and + * - the previous round with no read data didn't see consumed bytes + * (we might have a race with an interrupt being in flight while + * updating xencons->out_cons, so account for that by allowing one + * round without any visible reason) + */ + if (intf->out_cons != xencons->out_cons) { + xencons->out_cons = intf->out_cons; + xencons->out_cons_same = 0; + } + if (!recv && xencons->out_cons_same++ > 1) { + eoiflag = XEN_EOI_FLAG_SPURIOUS; + } + spin_unlock_irqrestore(&xencons->ring_lock, flags); + + if (recv) { + notify_daemon(xencons); + } + + xen_irq_lateeoi(xencons->irq, eoiflag); + + return recv; +} + +static const struct hv_ops domU_hvc_ops = { + .get_chars = domU_read_console, + .put_chars = domU_write_console, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int dom0_read_console(uint32_t vtermno, char *buf, int len) +{ + return HYPERVISOR_console_io(CONSOLEIO_read, len, buf); +} + +/* + * Either for a dom0 to write to the system console, or a domU with a + * debug version of Xen + */ +static int dom0_write_console(uint32_t vtermno, const char *str, int len) +{ + int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str); + if (rc < 0) + return rc; + + return len; +} + +static const struct hv_ops dom0_hvc_ops = { + .get_chars = dom0_read_console, + .put_chars = dom0_write_console, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int xen_hvm_console_init(void) +{ + int r; + uint64_t v = 0; + unsigned long gfn, flags; + struct xencons_info *info; + + if (!xen_hvm_domain()) + return -ENODEV; + + info = vtermno_to_xencons(HVC_COOKIE); + if (!info) { + info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL); + if (!info) + return -ENOMEM; + spin_lock_init(&info->ring_lock); + } else if (info->intf != NULL) { + /* already configured */ + return 0; + } + /* + * If the toolstack (or the hypervisor) hasn't set these values, the + * default value is 0. Even though gfn = 0 and evtchn = 0 are + * theoretically correct values, in practice they never are and they + * mean that a legacy toolstack hasn't initialized the pv console correctly. + */ + r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v); + if (r < 0 || v == 0) + goto err; + info->evtchn = v; + v = 0; + r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v); + if (r < 0 || v == 0) + goto err; + gfn = v; + info->intf = memremap(gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE, MEMREMAP_WB); + if (info->intf == NULL) + goto err; + info->vtermno = HVC_COOKIE; + + spin_lock_irqsave(&xencons_lock, flags); + list_add_tail(&info->list, &xenconsoles); + spin_unlock_irqrestore(&xencons_lock, flags); + + return 0; +err: + kfree(info); + return -ENODEV; +} + +static int xencons_info_pv_init(struct xencons_info *info, int vtermno) +{ + spin_lock_init(&info->ring_lock); + info->evtchn = xen_start_info->console.domU.evtchn; + /* GFN == MFN for PV guest */ + info->intf = gfn_to_virt(xen_start_info->console.domU.mfn); + info->vtermno = vtermno; + + list_add_tail(&info->list, &xenconsoles); + + return 0; +} + +static int xen_pv_console_init(void) +{ + struct xencons_info *info; + unsigned long flags; + + if (!xen_pv_domain()) + return -ENODEV; + + if (!xen_start_info->console.domU.evtchn) + return -ENODEV; + + info = vtermno_to_xencons(HVC_COOKIE); + if (!info) { + info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL); + if (!info) + return -ENOMEM; + } else if (info->intf != NULL) { + /* already configured */ + return 0; + } + spin_lock_irqsave(&xencons_lock, flags); + xencons_info_pv_init(info, HVC_COOKIE); + spin_unlock_irqrestore(&xencons_lock, flags); + + return 0; +} + +static int xen_initial_domain_console_init(void) +{ + struct xencons_info *info; + unsigned long flags; + + if (!xen_initial_domain()) + return -ENODEV; + + info = vtermno_to_xencons(HVC_COOKIE); + if (!info) { + info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL); + if (!info) + return -ENOMEM; + spin_lock_init(&info->ring_lock); + } + + info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false); + info->vtermno = HVC_COOKIE; + + spin_lock_irqsave(&xencons_lock, flags); + list_add_tail(&info->list, &xenconsoles); + spin_unlock_irqrestore(&xencons_lock, flags); + + return 0; +} + +static void xen_console_update_evtchn(struct xencons_info *info) +{ + if (xen_hvm_domain()) { + uint64_t v = 0; + int err; + + err = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v); + if (!err && v) + info->evtchn = v; + } else + info->evtchn = xen_start_info->console.domU.evtchn; +} + +void xen_console_resume(void) +{ + struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE); + if (info != NULL && info->irq) { + if (!xen_initial_domain()) + xen_console_update_evtchn(info); + rebind_evtchn_irq(info->evtchn, info->irq); + } +} + +#ifdef CONFIG_HVC_XEN_FRONTEND +static void xencons_disconnect_backend(struct xencons_info *info) +{ + if (info->hvc != NULL) + hvc_remove(info->hvc); + info->hvc = NULL; + if (info->irq > 0) { + evtchn_put(info->evtchn); + info->irq = 0; + info->evtchn = 0; + } + /* evtchn_put() will also close it so this is only an error path */ + if (info->evtchn > 0) + xenbus_free_evtchn(info->xbdev, info->evtchn); + info->evtchn = 0; + if (info->gntref > 0) + gnttab_free_grant_references(info->gntref); + info->gntref = 0; +} + +static void xencons_free(struct xencons_info *info) +{ + free_page((unsigned long)info->intf); + info->intf = NULL; + info->vtermno = 0; + kfree(info); +} + +static int xen_console_remove(struct xencons_info *info) +{ + unsigned long flags; + + xencons_disconnect_backend(info); + spin_lock_irqsave(&xencons_lock, flags); + list_del(&info->list); + spin_unlock_irqrestore(&xencons_lock, flags); + if (info->xbdev != NULL) + xencons_free(info); + else { + if (xen_hvm_domain()) + iounmap(info->intf); + kfree(info); + } + return 0; +} + +static int xencons_remove(struct xenbus_device *dev) +{ + return xen_console_remove(dev_get_drvdata(&dev->dev)); +} + +static int xencons_connect_backend(struct xenbus_device *dev, + struct xencons_info *info) +{ + int ret, evtchn, devid, ref, irq; + struct xenbus_transaction xbt; + grant_ref_t gref_head; + + ret = xenbus_alloc_evtchn(dev, &evtchn); + if (ret) + return ret; + info->evtchn = evtchn; + irq = bind_evtchn_to_irq_lateeoi(evtchn); + if (irq < 0) + return irq; + info->irq = irq; + devid = dev->nodename[strlen(dev->nodename) - 1] - '0'; + info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid), + irq, &domU_hvc_ops, 256); + if (IS_ERR(info->hvc)) + return PTR_ERR(info->hvc); + ret = gnttab_alloc_grant_references(1, &gref_head); + if (ret < 0) + return ret; + info->gntref = gref_head; + ref = gnttab_claim_grant_reference(&gref_head); + if (ref < 0) + return ref; + gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id, + virt_to_gfn(info->intf), 0); + + again: + ret = xenbus_transaction_start(&xbt); + if (ret) { + xenbus_dev_fatal(dev, ret, "starting transaction"); + return ret; + } + ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref); + if (ret) + goto error_xenbus; + ret = xenbus_printf(xbt, dev->nodename, "port", "%u", + evtchn); + if (ret) + goto error_xenbus; + ret = xenbus_transaction_end(xbt, 0); + if (ret) { + if (ret == -EAGAIN) + goto again; + xenbus_dev_fatal(dev, ret, "completing transaction"); + return ret; + } + + xenbus_switch_state(dev, XenbusStateInitialised); + return 0; + + error_xenbus: + xenbus_transaction_end(xbt, 1); + xenbus_dev_fatal(dev, ret, "writing xenstore"); + return ret; +} + +static int xencons_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + int ret, devid; + struct xencons_info *info; + unsigned long flags; + + devid = dev->nodename[strlen(dev->nodename) - 1] - '0'; + if (devid == 0) + return -ENODEV; + + info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL); + if (!info) + return -ENOMEM; + spin_lock_init(&info->ring_lock); + dev_set_drvdata(&dev->dev, info); + info->xbdev = dev; + info->vtermno = xenbus_devid_to_vtermno(devid); + info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!info->intf) + goto error_nomem; + + ret = xencons_connect_backend(dev, info); + if (ret < 0) + goto error; + spin_lock_irqsave(&xencons_lock, flags); + list_add_tail(&info->list, &xenconsoles); + spin_unlock_irqrestore(&xencons_lock, flags); + + return 0; + + error_nomem: + ret = -ENOMEM; + xenbus_dev_fatal(dev, ret, "allocating device memory"); + error: + xencons_disconnect_backend(info); + xencons_free(info); + return ret; +} + +static int xencons_resume(struct xenbus_device *dev) +{ + struct xencons_info *info = dev_get_drvdata(&dev->dev); + + xencons_disconnect_backend(info); + memset(info->intf, 0, XEN_PAGE_SIZE); + return xencons_connect_backend(dev, info); +} + +static void xencons_backend_changed(struct xenbus_device *dev, + enum xenbus_state backend_state) +{ + switch (backend_state) { + case XenbusStateReconfiguring: + case XenbusStateReconfigured: + case XenbusStateInitialising: + case XenbusStateInitialised: + case XenbusStateUnknown: + break; + + case XenbusStateInitWait: + break; + + case XenbusStateConnected: + xenbus_switch_state(dev, XenbusStateConnected); + break; + + case XenbusStateClosed: + if (dev->state == XenbusStateClosed) + break; + fallthrough; /* Missed the backend's CLOSING state */ + case XenbusStateClosing: { + struct xencons_info *info = dev_get_drvdata(&dev->dev);; + + /* + * Don't tear down the evtchn and grant ref before the other + * end has disconnected, but do stop userspace from trying + * to use the device before we allow the backend to close. + */ + if (info->hvc) { + hvc_remove(info->hvc); + info->hvc = NULL; + } + + xenbus_frontend_closed(dev); + break; + } + } +} + +static const struct xenbus_device_id xencons_ids[] = { + { "console" }, + { "" } +}; + +static struct xenbus_driver xencons_driver = { + .name = "xenconsole", + .ids = xencons_ids, + .probe = xencons_probe, + .remove = xencons_remove, + .resume = xencons_resume, + .otherend_changed = xencons_backend_changed, + .not_essential = true, +}; +#endif /* CONFIG_HVC_XEN_FRONTEND */ + +static int __init xen_hvc_init(void) +{ + int r; + struct xencons_info *info; + const struct hv_ops *ops; + + if (!xen_domain()) + return -ENODEV; + + if (xen_initial_domain()) { + ops = &dom0_hvc_ops; + r = xen_initial_domain_console_init(); + if (r < 0) + goto register_fe; + info = vtermno_to_xencons(HVC_COOKIE); + } else { + ops = &domU_hvc_ops; + if (xen_hvm_domain()) + r = xen_hvm_console_init(); + else + r = xen_pv_console_init(); + if (r < 0) + goto register_fe; + + info = vtermno_to_xencons(HVC_COOKIE); + info->irq = bind_evtchn_to_irq_lateeoi(info->evtchn); + } + if (info->irq < 0) + info->irq = 0; /* NO_IRQ */ + else + irq_set_noprobe(info->irq); + + info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256); + if (IS_ERR(info->hvc)) { + unsigned long flags; + + r = PTR_ERR(info->hvc); + spin_lock_irqsave(&xencons_lock, flags); + list_del(&info->list); + spin_unlock_irqrestore(&xencons_lock, flags); + if (info->irq) + evtchn_put(info->evtchn); + kfree(info); + return r; + } + + r = 0; + register_fe: +#ifdef CONFIG_HVC_XEN_FRONTEND + r = xenbus_register_frontend(&xencons_driver); +#endif + return r; +} +device_initcall(xen_hvc_init); + +static int xen_cons_init(void) +{ + const struct hv_ops *ops; + + if (!xen_domain()) + return 0; + + if (xen_initial_domain()) + ops = &dom0_hvc_ops; + else { + int r; + ops = &domU_hvc_ops; + + if (xen_hvm_domain()) + r = xen_hvm_console_init(); + else + r = xen_pv_console_init(); + if (r < 0) + return r; + } + + hvc_instantiate(HVC_COOKIE, 0, ops); + return 0; +} +console_initcall(xen_cons_init); + +#ifdef CONFIG_X86 +static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) +{ + if (xen_cpuid_base()) + outsb(0xe9, str, len); +} +#else +static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) { } +#endif + +#ifdef CONFIG_EARLY_PRINTK +static int __init xenboot_console_setup(struct console *console, char *string) +{ + static struct xencons_info xenboot; + + if (xen_initial_domain() || !xen_pv_domain()) + return 0; + + return xencons_info_pv_init(&xenboot, 0); +} + +static void xenboot_write_console(struct console *console, const char *string, + unsigned len) +{ + unsigned int linelen, off = 0; + const char *pos; + + if (dom0_write_console(0, string, len) >= 0) + return; + + if (!xen_pv_domain()) { + xen_hvm_early_write(0, string, len); + return; + } + + if (domU_write_console(0, "(early) ", 8) < 0) + return; + while (off < len && NULL != (pos = strchr(string+off, '\n'))) { + linelen = pos-string+off; + if (off + linelen > len) + break; + domU_write_console(0, string+off, linelen); + domU_write_console(0, "\r\n", 2); + off += linelen + 1; + } + if (off < len) + domU_write_console(0, string+off, len-off); +} + +struct console xenboot_console = { + .name = "xenboot", + .write = xenboot_write_console, + .setup = xenboot_console_setup, + .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME, + .index = -1, +}; +#endif /* CONFIG_EARLY_PRINTK */ + +void xen_raw_console_write(const char *str) +{ + ssize_t len = strlen(str); + int rc = 0; + + if (xen_domain()) { + rc = dom0_write_console(0, str, len); + if (rc != -ENOSYS || !xen_hvm_domain()) + return; + } + xen_hvm_early_write(0, str, len); +} + +void xen_raw_printk(const char *fmt, ...) +{ + static char buf[512]; + va_list ap; + + va_start(ap, fmt); + vsnprintf(buf, sizeof(buf), fmt, ap); + va_end(ap); + + xen_raw_console_write(buf); +} + +static void xenboot_earlycon_write(struct console *console, + const char *string, + unsigned len) +{ + dom0_write_console(0, string, len); +} + +static int __init xenboot_earlycon_setup(struct earlycon_device *device, + const char *opt) +{ + device->con->write = xenboot_earlycon_write; + return 0; +} +EARLYCON_DECLARE(xenboot, xenboot_earlycon_setup); diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c new file mode 100644 index 000000000..4ba249636 --- /dev/null +++ b/drivers/tty/hvc/hvcs.c @@ -0,0 +1,1571 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * IBM eServer Hypervisor Virtual Console Server Device Driver + * Copyright (C) 2003, 2004 IBM Corp. + * Ryan S. Arnold (rsa@us.ibm.com) + * + * Author(s) : Ryan S. Arnold <rsa@us.ibm.com> + * + * This is the device driver for the IBM Hypervisor Virtual Console Server, + * "hvcs". The IBM hvcs provides a tty driver interface to allow Linux + * user space applications access to the system consoles of logically + * partitioned operating systems, e.g. Linux, running on the same partitioned + * Power5 ppc64 system. Physical hardware consoles per partition are not + * practical on this hardware so system consoles are accessed by this driver + * using inter-partition firmware interfaces to virtual terminal devices. + * + * A vty is known to the HMC as a "virtual serial server adapter". It is a + * virtual terminal device that is created by firmware upon partition creation + * to act as a partitioned OS's console device. + * + * Firmware dynamically (via hotplug) exposes vty-servers to a running ppc64 + * Linux system upon their creation by the HMC or their exposure during boot. + * The non-user interactive backend of this driver is implemented as a vio + * device driver so that it can receive notification of vty-server lifetimes + * after it registers with the vio bus to handle vty-server probe and remove + * callbacks. + * + * Many vty-servers can be configured to connect to one vty, but a vty can + * only be actively connected to by a single vty-server, in any manner, at one + * time. If the HMC is currently hosting the console for a target Linux + * partition; attempts to open the tty device to the partition's console using + * the hvcs on any partition will return -EBUSY with every open attempt until + * the HMC frees the connection between its vty-server and the desired + * partition's vty device. Conversely, a vty-server may only be connected to + * a single vty at one time even though it may have several configured vty + * partner possibilities. + * + * Firmware does not provide notification of vty partner changes to this + * driver. This means that an HMC Super Admin may add or remove partner vtys + * from a vty-server's partner list but the changes will not be signaled to + * the vty-server. Firmware only notifies the driver when a vty-server is + * added or removed from the system. To compensate for this deficiency, this + * driver implements a sysfs update attribute which provides a method for + * rescanning partner information upon a user's request. + * + * Each vty-server, prior to being exposed to this driver is reference counted + * using the 2.6 Linux kernel kref construct. + * + * For direction on installation and usage of this driver please reference + * Documentation/powerpc/hvcs.rst. + */ + +#include <linux/device.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/kref.h> +#include <linux/kthread.h> +#include <linux/list.h> +#include <linux/major.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/stat.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <asm/hvconsole.h> +#include <asm/hvcserver.h> +#include <linux/uaccess.h> +#include <linux/termios_internal.h> +#include <asm/vio.h> + +/* + * 1.3.0 -> 1.3.1 In hvcs_open memset(..,0x00,..) instead of memset(..,0x3F,00). + * Removed braces around single statements following conditionals. Removed '= + * 0' after static int declarations since these default to zero. Removed + * list_for_each_safe() and replaced with list_for_each_entry() in + * hvcs_get_by_index(). The 'safe' version is un-needed now that the driver is + * using spinlocks. Changed spin_lock_irqsave() to spin_lock() when locking + * hvcs_structs_lock and hvcs_pi_lock since these are not touched in an int + * handler. Initialized hvcs_structs_lock and hvcs_pi_lock to + * SPIN_LOCK_UNLOCKED at declaration time rather than in hvcs_module_init(). + * Added spin_lock around list_del() in destroy_hvcs_struct() to protect the + * list traversals from a deletion. Removed '= NULL' from pointer declaration + * statements since they are initialized NULL by default. Removed wmb() + * instances from hvcs_try_write(). They probably aren't needed with locking in + * place. Added check and cleanup for hvcs_pi_buff = kmalloc() in + * hvcs_module_init(). Exposed hvcs_struct.index via a sysfs attribute so that + * the coupling between /dev/hvcs* and a vty-server can be automatically + * determined. Moved kobject_put() in hvcs_open outside of the + * spin_unlock_irqrestore(). + * + * 1.3.1 -> 1.3.2 Changed method for determining hvcs_struct->index and had it + * align with how the tty layer always assigns the lowest index available. This + * change resulted in a list of ints that denotes which indexes are available. + * Device additions and removals use the new hvcs_get_index() and + * hvcs_return_index() helper functions. The list is created with + * hvsc_alloc_index_list() and it is destroyed with hvcs_free_index_list(). + * Without these fixes hotplug vty-server adapter support goes crazy with this + * driver if the user removes a vty-server adapter. Moved free_irq() outside of + * the hvcs_final_close() function in order to get it out of the spinlock. + * Rearranged hvcs_close(). Cleaned up some printks and did some housekeeping + * on the changelog. Removed local CLC_LENGTH and used HVCS_CLC_LENGTH from + * arch/powerepc/include/asm/hvcserver.h + * + * 1.3.2 -> 1.3.3 Replaced yield() in hvcs_close() with tty_wait_until_sent() to + * prevent possible lockup with realtime scheduling as similarly pointed out by + * akpm in hvc_console. Changed resulted in the removal of hvcs_final_close() + * to reorder cleanup operations and prevent discarding of pending data during + * an hvcs_close(). Removed spinlock protection of hvcs_struct data members in + * hvcs_write_room() and hvcs_chars_in_buffer() because they aren't needed. + */ + +#define HVCS_DRIVER_VERSION "1.3.3" + +MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>"); +MODULE_DESCRIPTION("IBM hvcs (Hypervisor Virtual Console Server) Driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(HVCS_DRIVER_VERSION); + +/* + * Wait this long per iteration while trying to push buffered data to the + * hypervisor before allowing the tty to complete a close operation. + */ +#define HVCS_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ + +/* + * Since the Linux TTY code does not currently (2-04-2004) support dynamic + * addition of tty derived devices and we shouldn't allocate thousands of + * tty_device pointers when the number of vty-server & vty partner connections + * will most often be much lower than this, we'll arbitrarily allocate + * HVCS_DEFAULT_SERVER_ADAPTERS tty_structs and cdev's by default when we + * register the tty_driver. This can be overridden using an insmod parameter. + */ +#define HVCS_DEFAULT_SERVER_ADAPTERS 64 + +/* + * The user can't insmod with more than HVCS_MAX_SERVER_ADAPTERS hvcs device + * nodes as a sanity check. Theoretically there can be over 1 Billion + * vty-server & vty partner connections. + */ +#define HVCS_MAX_SERVER_ADAPTERS 1024 + +/* + * We let Linux assign us a major number and we start the minors at zero. There + * is no intuitive mapping between minor number and the target vty-server + * adapter except that each new vty-server adapter is always assigned to the + * smallest minor number available. + */ +#define HVCS_MINOR_START 0 + +/* + * The hcall interface involves putting 8 chars into each of two registers. + * We load up those 2 registers (in arch/powerpc/platforms/pseries/hvconsole.c) + * by casting char[16] to long[2]. It would work without __ALIGNED__, but a + * little (tiny) bit slower because an unaligned load is slower than aligned + * load. + */ +#define __ALIGNED__ __attribute__((__aligned__(8))) + +/* + * How much data can firmware send with each hvc_put_chars()? Maybe this + * should be moved into an architecture specific area. + */ +#define HVCS_BUFF_LEN 16 + +/* + * This is the maximum amount of data we'll let the user send us (hvcs_write) at + * once in a chunk as a sanity check. + */ +#define HVCS_MAX_FROM_USER 4096 + +/* + * Be careful when adding flags to this line discipline. Don't add anything + * that will cause echoing or we'll go into recursive loop echoing chars back + * and forth with the console drivers. + */ +static const struct ktermios hvcs_tty_termios = { + .c_iflag = IGNBRK | IGNPAR, + .c_oflag = OPOST, + .c_cflag = B38400 | CS8 | CREAD | HUPCL, + .c_cc = INIT_C_CC, + .c_ispeed = 38400, + .c_ospeed = 38400 +}; + +/* + * This value is used to take the place of a command line parameter when the + * module is inserted. It starts as -1 and stays as such if the user doesn't + * specify a module insmod parameter. If they DO specify one then it is set to + * the value of the integer passed in. + */ +static int hvcs_parm_num_devs = -1; +module_param(hvcs_parm_num_devs, int, 0); + +static const char hvcs_driver_name[] = "hvcs"; +static const char hvcs_device_node[] = "hvcs"; + +/* Status of partner info rescan triggered via sysfs. */ +static int hvcs_rescan_status; + +static struct tty_driver *hvcs_tty_driver; + +/* + * In order to be somewhat sane this driver always associates the hvcs_struct + * index element with the numerically equal tty->index. This means that a + * hotplugged vty-server adapter will always map to the lowest index valued + * device node. If vty-servers were hotplug removed from the system and then + * new ones added the new vty-server may have the largest slot number of all + * the vty-server adapters in the partition but it may have the lowest dev node + * index of all the adapters due to the hole left by the hotplug removed + * adapter. There are a set of functions provided to get the lowest index for + * a new device as well as return the index to the list. This list is allocated + * with a number of elements equal to the number of device nodes requested when + * the module was inserted. + */ +static int *hvcs_index_list; + +/* + * How large is the list? This is kept for traversal since the list is + * dynamically created. + */ +static int hvcs_index_count; + +/* + * Used by the khvcsd to pick up I/O operations when the kernel_thread is + * already awake but potentially shifted to TASK_INTERRUPTIBLE state. + */ +static int hvcs_kicked; + +/* + * Use by the kthread construct for task operations like waking the sleeping + * thread and stopping the kthread. + */ +static struct task_struct *hvcs_task; + +/* + * We allocate this for the use of all of the hvcs_structs when they fetch + * partner info. + */ +static unsigned long *hvcs_pi_buff; + +/* Only allow one hvcs_struct to use the hvcs_pi_buff at a time. */ +static DEFINE_SPINLOCK(hvcs_pi_lock); + +/* One vty-server per hvcs_struct */ +struct hvcs_struct { + struct tty_port port; + spinlock_t lock; + + /* + * This index identifies this hvcs device as the complement to a + * specific tty index. + */ + unsigned int index; + + /* + * Used to tell the driver kernel_thread what operations need to take + * place upon this hvcs_struct instance. + */ + int todo_mask; + + /* + * This buffer is required so that when hvcs_write_room() reports that + * it can send HVCS_BUFF_LEN characters that it will buffer the full + * HVCS_BUFF_LEN characters if need be. This is essential for opost + * writes since they do not do high level buffering and expect to be + * able to send what the driver commits to sending buffering + * [e.g. tab to space conversions in n_tty.c opost()]. + */ + char buffer[HVCS_BUFF_LEN]; + int chars_in_buffer; + + /* + * Any variable below is valid before a tty is connected and + * stays valid after the tty is disconnected. These shouldn't be + * whacked until the kobject refcount reaches zero though some entries + * may be changed via sysfs initiatives. + */ + int connected; /* is the vty-server currently connected to a vty? */ + uint32_t p_unit_address; /* partner unit address */ + uint32_t p_partition_ID; /* partner partition ID */ + char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */ + struct list_head next; /* list management */ + struct vio_dev *vdev; +}; + +static LIST_HEAD(hvcs_structs); +static DEFINE_SPINLOCK(hvcs_structs_lock); +static DEFINE_MUTEX(hvcs_init_mutex); + +static int hvcs_get_pi(struct hvcs_struct *hvcsd); +static int hvcs_rescan_devices_list(void); + +static void hvcs_partner_free(struct hvcs_struct *hvcsd); + +static int hvcs_initialize(void); + +#define HVCS_SCHED_READ 0x00000001 +#define HVCS_QUICK_READ 0x00000002 +#define HVCS_TRY_WRITE 0x00000004 +#define HVCS_READ_MASK (HVCS_SCHED_READ | HVCS_QUICK_READ) + +static inline struct hvcs_struct *from_vio_dev(struct vio_dev *viod) +{ + return dev_get_drvdata(&viod->dev); +} +/* The sysfs interface for the driver and devices */ + +static ssize_t hvcs_partner_vtys_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%X\n", hvcsd->p_unit_address); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} +static DEVICE_ATTR(partner_vtys, S_IRUGO, hvcs_partner_vtys_show, NULL); + +static ssize_t hvcs_partner_clcs_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} +static DEVICE_ATTR(partner_clcs, S_IRUGO, hvcs_partner_clcs_show, NULL); + +static ssize_t hvcs_current_vty_store(struct device *dev, struct device_attribute *attr, const char * buf, + size_t count) +{ + /* + * Don't need this feature at the present time because firmware doesn't + * yet support multiple partners. + */ + printk(KERN_INFO "HVCS: Denied current_vty change: -EPERM.\n"); + return -EPERM; +} + +static ssize_t hvcs_current_vty_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} + +static DEVICE_ATTR(current_vty, + S_IRUGO | S_IWUSR, hvcs_current_vty_show, hvcs_current_vty_store); + +static ssize_t hvcs_vterm_state_store(struct device *dev, struct device_attribute *attr, const char *buf, + size_t count) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + + /* writing a '0' to this sysfs entry will result in the disconnect. */ + if (simple_strtol(buf, NULL, 0) != 0) + return -EINVAL; + + spin_lock_irqsave(&hvcsd->lock, flags); + + if (hvcsd->port.count > 0) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + printk(KERN_INFO "HVCS: vterm state unchanged. " + "The hvcs device node is still in use.\n"); + return -EPERM; + } + + if (hvcsd->connected == 0) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + printk(KERN_INFO "HVCS: vterm state unchanged. The" + " vty-server is not connected to a vty.\n"); + return -EPERM; + } + + hvcs_partner_free(hvcsd); + printk(KERN_INFO "HVCS: Closed vty-server@%X and" + " partner vty@%X:%d connection.\n", + hvcsd->vdev->unit_address, + hvcsd->p_unit_address, + (uint32_t)hvcsd->p_partition_ID); + + spin_unlock_irqrestore(&hvcsd->lock, flags); + return count; +} + +static ssize_t hvcs_vterm_state_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%d\n", hvcsd->connected); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} +static DEVICE_ATTR(vterm_state, S_IRUGO | S_IWUSR, + hvcs_vterm_state_show, hvcs_vterm_state_store); + +static ssize_t hvcs_index_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%d\n", hvcsd->index); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} + +static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL); + +static struct attribute *hvcs_attrs[] = { + &dev_attr_partner_vtys.attr, + &dev_attr_partner_clcs.attr, + &dev_attr_current_vty.attr, + &dev_attr_vterm_state.attr, + &dev_attr_index.attr, + NULL, +}; + +static struct attribute_group hvcs_attr_group = { + .attrs = hvcs_attrs, +}; + +static ssize_t rescan_show(struct device_driver *ddp, char *buf) +{ + /* A 1 means it is updating, a 0 means it is done updating */ + return snprintf(buf, PAGE_SIZE, "%d\n", hvcs_rescan_status); +} + +static ssize_t rescan_store(struct device_driver *ddp, const char * buf, + size_t count) +{ + if ((simple_strtol(buf, NULL, 0) != 1) + && (hvcs_rescan_status != 0)) + return -EINVAL; + + hvcs_rescan_status = 1; + printk(KERN_INFO "HVCS: rescanning partner info for all" + " vty-servers.\n"); + hvcs_rescan_devices_list(); + hvcs_rescan_status = 0; + return count; +} + +static DRIVER_ATTR_RW(rescan); + +static void hvcs_kick(void) +{ + hvcs_kicked = 1; + wmb(); + wake_up_process(hvcs_task); +} + +static void hvcs_unthrottle(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned long flags; + + spin_lock_irqsave(&hvcsd->lock, flags); + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock_irqrestore(&hvcsd->lock, flags); + hvcs_kick(); +} + +static void hvcs_throttle(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned long flags; + + spin_lock_irqsave(&hvcsd->lock, flags); + vio_disable_interrupts(hvcsd->vdev); + spin_unlock_irqrestore(&hvcsd->lock, flags); +} + +/* + * If the device is being removed we don't have to worry about this interrupt + * handler taking any further interrupts because they are disabled which means + * the hvcs_struct will always be valid in this handler. + */ +static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance) +{ + struct hvcs_struct *hvcsd = dev_instance; + + spin_lock(&hvcsd->lock); + vio_disable_interrupts(hvcsd->vdev); + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock(&hvcsd->lock); + hvcs_kick(); + + return IRQ_HANDLED; +} + +/* This function must be called with the hvcsd->lock held */ +static void hvcs_try_write(struct hvcs_struct *hvcsd) +{ + uint32_t unit_address = hvcsd->vdev->unit_address; + struct tty_struct *tty = hvcsd->port.tty; + int sent; + + if (hvcsd->todo_mask & HVCS_TRY_WRITE) { + /* won't send partial writes */ + sent = hvc_put_chars(unit_address, + &hvcsd->buffer[0], + hvcsd->chars_in_buffer ); + if (sent > 0) { + hvcsd->chars_in_buffer = 0; + /* wmb(); */ + hvcsd->todo_mask &= ~(HVCS_TRY_WRITE); + /* wmb(); */ + + /* + * We are still obligated to deliver the data to the + * hypervisor even if the tty has been closed because + * we committed to delivering it. But don't try to wake + * a non-existent tty. + */ + if (tty) { + tty_wakeup(tty); + } + } + } +} + +static int hvcs_io(struct hvcs_struct *hvcsd) +{ + uint32_t unit_address; + struct tty_struct *tty; + char buf[HVCS_BUFF_LEN] __ALIGNED__; + unsigned long flags; + int got = 0; + + spin_lock_irqsave(&hvcsd->lock, flags); + + unit_address = hvcsd->vdev->unit_address; + tty = hvcsd->port.tty; + + hvcs_try_write(hvcsd); + + if (!tty || tty_throttled(tty)) { + hvcsd->todo_mask &= ~(HVCS_READ_MASK); + goto bail; + } else if (!(hvcsd->todo_mask & (HVCS_READ_MASK))) + goto bail; + + /* remove the read masks */ + hvcsd->todo_mask &= ~(HVCS_READ_MASK); + + if (tty_buffer_request_room(&hvcsd->port, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) { + got = hvc_get_chars(unit_address, + &buf[0], + HVCS_BUFF_LEN); + tty_insert_flip_string(&hvcsd->port, buf, got); + } + + /* Give the TTY time to process the data we just sent. */ + if (got) + hvcsd->todo_mask |= HVCS_QUICK_READ; + + spin_unlock_irqrestore(&hvcsd->lock, flags); + /* This is synch -- FIXME :js: it is not! */ + if (got) + tty_flip_buffer_push(&hvcsd->port); + else { + /* Do this _after_ the flip_buffer_push */ + spin_lock_irqsave(&hvcsd->lock, flags); + vio_enable_interrupts(hvcsd->vdev); + spin_unlock_irqrestore(&hvcsd->lock, flags); + } + + return hvcsd->todo_mask; + + bail: + spin_unlock_irqrestore(&hvcsd->lock, flags); + return hvcsd->todo_mask; +} + +static int khvcsd(void *unused) +{ + struct hvcs_struct *hvcsd; + int hvcs_todo_mask; + + __set_current_state(TASK_RUNNING); + + do { + hvcs_todo_mask = 0; + hvcs_kicked = 0; + wmb(); + + spin_lock(&hvcs_structs_lock); + list_for_each_entry(hvcsd, &hvcs_structs, next) { + hvcs_todo_mask |= hvcs_io(hvcsd); + } + spin_unlock(&hvcs_structs_lock); + + /* + * If any of the hvcs adapters want to try a write or quick read + * don't schedule(), yield a smidgen then execute the hvcs_io + * thread again for those that want the write. + */ + if (hvcs_todo_mask & (HVCS_TRY_WRITE | HVCS_QUICK_READ)) { + yield(); + continue; + } + + set_current_state(TASK_INTERRUPTIBLE); + if (!hvcs_kicked) + schedule(); + __set_current_state(TASK_RUNNING); + } while (!kthread_should_stop()); + + return 0; +} + +static const struct vio_device_id hvcs_driver_table[] = { + {"serial-server", "hvterm2"}, + { "", "" } +}; +MODULE_DEVICE_TABLE(vio, hvcs_driver_table); + +static void hvcs_return_index(int index) +{ + /* Paranoia check */ + if (!hvcs_index_list) + return; + if (index < 0 || index >= hvcs_index_count) + return; + if (hvcs_index_list[index] == -1) + return; + else + hvcs_index_list[index] = -1; +} + +static void hvcs_destruct_port(struct tty_port *p) +{ + struct hvcs_struct *hvcsd = container_of(p, struct hvcs_struct, port); + struct vio_dev *vdev; + unsigned long flags; + + spin_lock(&hvcs_structs_lock); + spin_lock_irqsave(&hvcsd->lock, flags); + + /* the list_del poisons the pointers */ + list_del(&(hvcsd->next)); + + if (hvcsd->connected == 1) { + hvcs_partner_free(hvcsd); + printk(KERN_INFO "HVCS: Closed vty-server@%X and" + " partner vty@%X:%d connection.\n", + hvcsd->vdev->unit_address, + hvcsd->p_unit_address, + (uint32_t)hvcsd->p_partition_ID); + } + printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n", + hvcsd->vdev->unit_address); + + vdev = hvcsd->vdev; + hvcsd->vdev = NULL; + + hvcsd->p_unit_address = 0; + hvcsd->p_partition_ID = 0; + hvcs_return_index(hvcsd->index); + memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1); + + spin_unlock_irqrestore(&hvcsd->lock, flags); + spin_unlock(&hvcs_structs_lock); + + sysfs_remove_group(&vdev->dev.kobj, &hvcs_attr_group); + + kfree(hvcsd); +} + +static const struct tty_port_operations hvcs_port_ops = { + .destruct = hvcs_destruct_port, +}; + +static int hvcs_get_index(void) +{ + int i; + /* Paranoia check */ + if (!hvcs_index_list) { + printk(KERN_ERR "HVCS: hvcs_index_list NOT valid!.\n"); + return -EFAULT; + } + /* Find the numerically lowest first free index. */ + for(i = 0; i < hvcs_index_count; i++) { + if (hvcs_index_list[i] == -1) { + hvcs_index_list[i] = 0; + return i; + } + } + return -1; +} + +static int hvcs_probe( + struct vio_dev *dev, + const struct vio_device_id *id) +{ + struct hvcs_struct *hvcsd; + int index, rc; + int retval; + + if (!dev || !id) { + printk(KERN_ERR "HVCS: probed with invalid parameter.\n"); + return -EPERM; + } + + /* Make sure we are properly initialized */ + rc = hvcs_initialize(); + if (rc) { + pr_err("HVCS: Failed to initialize core driver.\n"); + return rc; + } + + /* early to avoid cleanup on failure */ + index = hvcs_get_index(); + if (index < 0) { + return -EFAULT; + } + + hvcsd = kzalloc(sizeof(*hvcsd), GFP_KERNEL); + if (!hvcsd) + return -ENODEV; + + tty_port_init(&hvcsd->port); + hvcsd->port.ops = &hvcs_port_ops; + spin_lock_init(&hvcsd->lock); + + hvcsd->vdev = dev; + dev_set_drvdata(&dev->dev, hvcsd); + + hvcsd->index = index; + + /* hvcsd->index = ++hvcs_struct_count; */ + hvcsd->chars_in_buffer = 0; + hvcsd->todo_mask = 0; + hvcsd->connected = 0; + + /* + * This will populate the hvcs_struct's partner info fields for the + * first time. + */ + if (hvcs_get_pi(hvcsd)) { + printk(KERN_ERR "HVCS: Failed to fetch partner" + " info for vty-server@%X on device probe.\n", + hvcsd->vdev->unit_address); + } + + /* + * If a user app opens a tty that corresponds to this vty-server before + * the hvcs_struct has been added to the devices list then the user app + * will get -ENODEV. + */ + spin_lock(&hvcs_structs_lock); + list_add_tail(&(hvcsd->next), &hvcs_structs); + spin_unlock(&hvcs_structs_lock); + + retval = sysfs_create_group(&dev->dev.kobj, &hvcs_attr_group); + if (retval) { + printk(KERN_ERR "HVCS: Can't create sysfs attrs for vty-server@%X\n", + hvcsd->vdev->unit_address); + return retval; + } + + printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address); + + /* + * DON'T enable interrupts here because there is no user to receive the + * data. + */ + return 0; +} + +static void hvcs_remove(struct vio_dev *dev) +{ + struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev); + unsigned long flags; + struct tty_struct *tty; + + /* By this time the vty-server won't be getting any more interrupts */ + + spin_lock_irqsave(&hvcsd->lock, flags); + + tty = hvcsd->port.tty; + + spin_unlock_irqrestore(&hvcsd->lock, flags); + + /* + * Let the last holder of this object cause it to be removed, which + * would probably be tty_hangup below. + */ + tty_port_put(&hvcsd->port); + + /* + * The hangup is a scheduled function which will auto chain call + * hvcs_hangup. The tty should always be valid at this time unless a + * simultaneous tty close already cleaned up the hvcs_struct. + */ + if (tty) + tty_hangup(tty); + + printk(KERN_INFO "HVCS: vty-server@%X removed from the" + " vio bus.\n", dev->unit_address); +}; + +static struct vio_driver hvcs_vio_driver = { + .id_table = hvcs_driver_table, + .probe = hvcs_probe, + .remove = hvcs_remove, + .name = hvcs_driver_name, +}; + +/* Only called from hvcs_get_pi please */ +static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd) +{ + hvcsd->p_unit_address = pi->unit_address; + hvcsd->p_partition_ID = pi->partition_ID; + + /* copy the null-term char too */ + strscpy(hvcsd->p_location_code, pi->location_code, + sizeof(hvcsd->p_location_code)); +} + +/* + * Traverse the list and add the partner info that is found to the hvcs_struct + * struct entry. NOTE: At this time I know that partner info will return a + * single entry but in the future there may be multiple partner info entries per + * vty-server and you'll want to zero out that list and reset it. If for some + * reason you have an old version of this driver but there IS more than one + * partner info then hvcsd->p_* will hold the last partner info data from the + * firmware query. A good way to update this code would be to replace the three + * partner info fields in hvcs_struct with a list of hvcs_partner_info + * instances. + * + * This function must be called with the hvcsd->lock held. + */ +static int hvcs_get_pi(struct hvcs_struct *hvcsd) +{ + struct hvcs_partner_info *pi; + uint32_t unit_address = hvcsd->vdev->unit_address; + struct list_head head; + int retval; + + spin_lock(&hvcs_pi_lock); + if (!hvcs_pi_buff) { + spin_unlock(&hvcs_pi_lock); + return -EFAULT; + } + retval = hvcs_get_partner_info(unit_address, &head, hvcs_pi_buff); + spin_unlock(&hvcs_pi_lock); + if (retval) { + printk(KERN_ERR "HVCS: Failed to fetch partner" + " info for vty-server@%x.\n", unit_address); + return retval; + } + + /* nixes the values if the partner vty went away */ + hvcsd->p_unit_address = 0; + hvcsd->p_partition_ID = 0; + + list_for_each_entry(pi, &head, node) + hvcs_set_pi(pi, hvcsd); + + hvcs_free_partner_info(&head); + return 0; +} + +/* + * This function is executed by the driver "rescan" sysfs entry. It shouldn't + * be executed elsewhere, in order to prevent deadlock issues. + */ +static int hvcs_rescan_devices_list(void) +{ + struct hvcs_struct *hvcsd; + unsigned long flags; + + spin_lock(&hvcs_structs_lock); + + list_for_each_entry(hvcsd, &hvcs_structs, next) { + spin_lock_irqsave(&hvcsd->lock, flags); + hvcs_get_pi(hvcsd); + spin_unlock_irqrestore(&hvcsd->lock, flags); + } + + spin_unlock(&hvcs_structs_lock); + + return 0; +} + +/* + * Farm this off into its own function because it could be more complex once + * multiple partners support is added. This function should be called with + * the hvcsd->lock held. + */ +static int hvcs_has_pi(struct hvcs_struct *hvcsd) +{ + if ((!hvcsd->p_unit_address) || (!hvcsd->p_partition_ID)) + return 0; + return 1; +} + +/* + * NOTE: It is possible that the super admin removed a partner vty and then + * added a different vty as the new partner. + * + * This function must be called with the hvcsd->lock held. + */ +static int hvcs_partner_connect(struct hvcs_struct *hvcsd) +{ + int retval; + unsigned int unit_address = hvcsd->vdev->unit_address; + + /* + * If there wasn't any pi when the device was added it doesn't meant + * there isn't any now. This driver isn't notified when a new partner + * vty is added to a vty-server so we discover changes on our own. + * Please see comments in hvcs_register_connection() for justification + * of this bizarre code. + */ + retval = hvcs_register_connection(unit_address, + hvcsd->p_partition_ID, + hvcsd->p_unit_address); + if (!retval) { + hvcsd->connected = 1; + return 0; + } else if (retval != -EINVAL) + return retval; + + /* + * As per the spec re-get the pi and try again if -EINVAL after the + * first connection attempt. + */ + if (hvcs_get_pi(hvcsd)) + return -ENOMEM; + + if (!hvcs_has_pi(hvcsd)) + return -ENODEV; + + retval = hvcs_register_connection(unit_address, + hvcsd->p_partition_ID, + hvcsd->p_unit_address); + if (retval != -EINVAL) { + hvcsd->connected = 1; + return retval; + } + + /* + * EBUSY is the most likely scenario though the vty could have been + * removed or there really could be an hcall error due to the parameter + * data but thanks to ambiguous firmware return codes we can't really + * tell. + */ + printk(KERN_INFO "HVCS: vty-server or partner" + " vty is busy. Try again later.\n"); + return -EBUSY; +} + +/* This function must be called with the hvcsd->lock held */ +static void hvcs_partner_free(struct hvcs_struct *hvcsd) +{ + int retval; + do { + retval = hvcs_free_connection(hvcsd->vdev->unit_address); + } while (retval == -EBUSY); + hvcsd->connected = 0; +} + +/* This helper function must be called WITHOUT the hvcsd->lock held */ +static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address, + unsigned int irq, struct vio_dev *vdev) +{ + unsigned long flags; + int rc; + + /* + * It is possible that the vty-server was removed between the time that + * the conn was registered and now. + */ + rc = request_irq(irq, &hvcs_handle_interrupt, 0, "ibmhvcs", hvcsd); + if (!rc) { + /* + * It is possible the vty-server was removed after the irq was + * requested but before we have time to enable interrupts. + */ + if (vio_enable_interrupts(vdev) == H_SUCCESS) + return 0; + else { + printk(KERN_ERR "HVCS: int enable failed for" + " vty-server@%X.\n", unit_address); + free_irq(irq, hvcsd); + } + } else + printk(KERN_ERR "HVCS: irq req failed for" + " vty-server@%X.\n", unit_address); + + spin_lock_irqsave(&hvcsd->lock, flags); + hvcs_partner_free(hvcsd); + spin_unlock_irqrestore(&hvcsd->lock, flags); + + return rc; + +} + +/* + * This always increments the kref ref count if the call is successful. + * Please remember to dec when you are done with the instance. + * + * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when + * calling this function or you will get deadlock. + */ +static struct hvcs_struct *hvcs_get_by_index(int index) +{ + struct hvcs_struct *hvcsd; + unsigned long flags; + + spin_lock(&hvcs_structs_lock); + list_for_each_entry(hvcsd, &hvcs_structs, next) { + spin_lock_irqsave(&hvcsd->lock, flags); + if (hvcsd->index == index) { + tty_port_get(&hvcsd->port); + spin_unlock_irqrestore(&hvcsd->lock, flags); + spin_unlock(&hvcs_structs_lock); + return hvcsd; + } + spin_unlock_irqrestore(&hvcsd->lock, flags); + } + spin_unlock(&hvcs_structs_lock); + + return NULL; +} + +static int hvcs_install(struct tty_driver *driver, struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd; + struct vio_dev *vdev; + unsigned long unit_address, flags; + unsigned int irq; + int retval; + + /* + * Is there a vty-server that shares the same index? + * This function increments the kref index. + */ + hvcsd = hvcs_get_by_index(tty->index); + if (!hvcsd) { + printk(KERN_WARNING "HVCS: open failed, no device associated" + " with tty->index %d.\n", tty->index); + return -ENODEV; + } + + spin_lock_irqsave(&hvcsd->lock, flags); + + if (hvcsd->connected == 0) { + retval = hvcs_partner_connect(hvcsd); + if (retval) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + printk(KERN_WARNING "HVCS: partner connect failed.\n"); + goto err_put; + } + } + + hvcsd->port.count = 0; + hvcsd->port.tty = tty; + tty->driver_data = hvcsd; + + memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); + + /* + * Save these in the spinlock for the enable operations that need them + * outside of the spinlock. + */ + irq = hvcsd->vdev->irq; + vdev = hvcsd->vdev; + unit_address = hvcsd->vdev->unit_address; + + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock_irqrestore(&hvcsd->lock, flags); + + /* + * This must be done outside of the spinlock because it requests irqs + * and will grab the spinlock and free the connection if it fails. + */ + retval = hvcs_enable_device(hvcsd, unit_address, irq, vdev); + if (retval) { + printk(KERN_WARNING "HVCS: enable device failed.\n"); + goto err_put; + } + + retval = tty_port_install(&hvcsd->port, driver, tty); + if (retval) + goto err_irq; + + return 0; +err_irq: + spin_lock_irqsave(&hvcsd->lock, flags); + vio_disable_interrupts(hvcsd->vdev); + spin_unlock_irqrestore(&hvcsd->lock, flags); + free_irq(irq, hvcsd); +err_put: + tty_port_put(&hvcsd->port); + + return retval; +} + +/* + * This is invoked via the tty_open interface when a user app connects to the + * /dev node. + */ +static int hvcs_open(struct tty_struct *tty, struct file *filp) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned long flags; + + spin_lock_irqsave(&hvcsd->lock, flags); + hvcsd->port.count++; + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock_irqrestore(&hvcsd->lock, flags); + + hvcs_kick(); + + printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n", + hvcsd->vdev->unit_address ); + + return 0; +} + +static void hvcs_close(struct tty_struct *tty, struct file *filp) +{ + struct hvcs_struct *hvcsd; + unsigned long flags; + int irq; + + /* + * Is someone trying to close the file associated with this device after + * we have hung up? If so tty->driver_data wouldn't be valid. + */ + if (tty_hung_up_p(filp)) + return; + + /* + * No driver_data means that this close was probably issued after a + * failed hvcs_open by the tty layer's release_dev() api and we can just + * exit cleanly. + */ + if (!tty->driver_data) + return; + + hvcsd = tty->driver_data; + + spin_lock_irqsave(&hvcsd->lock, flags); + if (--hvcsd->port.count == 0) { + + vio_disable_interrupts(hvcsd->vdev); + + /* + * NULL this early so that the kernel_thread doesn't try to + * execute any operations on the TTY even though it is obligated + * to deliver any pending I/O to the hypervisor. + */ + hvcsd->port.tty = NULL; + + irq = hvcsd->vdev->irq; + spin_unlock_irqrestore(&hvcsd->lock, flags); + + tty_wait_until_sent(tty, HVCS_CLOSE_WAIT); + + free_irq(irq, hvcsd); + return; + } else if (hvcsd->port.count < 0) { + printk(KERN_ERR "HVCS: vty-server@%X open_count: %d is mismanaged.\n", + hvcsd->vdev->unit_address, hvcsd->port.count); + } + + spin_unlock_irqrestore(&hvcsd->lock, flags); +} + +static void hvcs_cleanup(struct tty_struct * tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + + /* + * This line is important because it tells hvcs_open that this + * device needs to be re-configured the next time hvcs_open is + * called. + */ + tty->driver_data = NULL; + + tty_port_put(&hvcsd->port); +} + +static void hvcs_hangup(struct tty_struct * tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned long flags; + int temp_open_count; + int irq; + + spin_lock_irqsave(&hvcsd->lock, flags); + /* Preserve this so that we know how many kref refs to put */ + temp_open_count = hvcsd->port.count; + + /* + * Don't kref put inside the spinlock because the destruction + * callback may use the spinlock and it may get called before the + * spinlock has been released. + */ + vio_disable_interrupts(hvcsd->vdev); + + hvcsd->todo_mask = 0; + + /* I don't think the tty needs the hvcs_struct pointer after a hangup */ + tty->driver_data = NULL; + hvcsd->port.tty = NULL; + + hvcsd->port.count = 0; + + /* This will drop any buffered data on the floor which is OK in a hangup + * scenario. */ + memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); + hvcsd->chars_in_buffer = 0; + + irq = hvcsd->vdev->irq; + + spin_unlock_irqrestore(&hvcsd->lock, flags); + + free_irq(irq, hvcsd); + + /* + * We need to kref_put() for every open_count we have since the + * tty_hangup() function doesn't invoke a close per open connection on a + * non-console device. + */ + while(temp_open_count) { + --temp_open_count; + /* + * The final put will trigger destruction of the hvcs_struct. + * NOTE: If this hangup was signaled from user space then the + * final put will never happen. + */ + tty_port_put(&hvcsd->port); + } +} + +/* + * NOTE: This is almost always from_user since user level apps interact with the + * /dev nodes. I'm trusting that if hvcs_write gets called and interrupted by + * hvcs_remove (which removes the target device and executes tty_hangup()) that + * tty_hangup will allow hvcs_write time to complete execution before it + * terminates our device. + */ +static int hvcs_write(struct tty_struct *tty, + const unsigned char *buf, int count) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned int unit_address; + const unsigned char *charbuf; + unsigned long flags; + int total_sent = 0; + int tosend = 0; + int result = 0; + + /* + * If they don't check the return code off of their open they may + * attempt this even if there is no connected device. + */ + if (!hvcsd) + return -ENODEV; + + /* Reasonable size to prevent user level flooding */ + if (count > HVCS_MAX_FROM_USER) { + printk(KERN_WARNING "HVCS write: count being truncated to" + " HVCS_MAX_FROM_USER.\n"); + count = HVCS_MAX_FROM_USER; + } + + charbuf = buf; + + spin_lock_irqsave(&hvcsd->lock, flags); + + /* + * Somehow an open succeeded but the device was removed or the + * connection terminated between the vty-server and partner vty during + * the middle of a write operation? This is a crummy place to do this + * but we want to keep it all in the spinlock. + */ + if (hvcsd->port.count <= 0) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + return -ENODEV; + } + + unit_address = hvcsd->vdev->unit_address; + + while (count > 0) { + tosend = min(count, (HVCS_BUFF_LEN - hvcsd->chars_in_buffer)); + /* + * No more space, this probably means that the last call to + * hvcs_write() didn't succeed and the buffer was filled up. + */ + if (!tosend) + break; + + memcpy(&hvcsd->buffer[hvcsd->chars_in_buffer], + &charbuf[total_sent], + tosend); + + hvcsd->chars_in_buffer += tosend; + + result = 0; + + /* + * If this is true then we don't want to try writing to the + * hypervisor because that is the kernel_threads job now. We'll + * just add to the buffer. + */ + if (!(hvcsd->todo_mask & HVCS_TRY_WRITE)) + /* won't send partial writes */ + result = hvc_put_chars(unit_address, + &hvcsd->buffer[0], + hvcsd->chars_in_buffer); + + /* + * Since we know we have enough room in hvcsd->buffer for + * tosend we record that it was sent regardless of whether the + * hypervisor actually took it because we have it buffered. + */ + total_sent+=tosend; + count-=tosend; + if (result == 0) { + hvcsd->todo_mask |= HVCS_TRY_WRITE; + hvcs_kick(); + break; + } + + hvcsd->chars_in_buffer = 0; + /* + * Test after the chars_in_buffer reset otherwise this could + * deadlock our writes if hvc_put_chars fails. + */ + if (result < 0) + break; + } + + spin_unlock_irqrestore(&hvcsd->lock, flags); + + if (result == -1) + return -EIO; + else + return total_sent; +} + +/* + * This is really asking how much can we guarantee that we can send or that we + * absolutely WILL BUFFER if we can't send it. This driver MUST honor the + * return value, hence the reason for hvcs_struct buffering. + */ +static unsigned int hvcs_write_room(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + + if (!hvcsd || hvcsd->port.count <= 0) + return 0; + + return HVCS_BUFF_LEN - hvcsd->chars_in_buffer; +} + +static unsigned int hvcs_chars_in_buffer(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + + return hvcsd->chars_in_buffer; +} + +static const struct tty_operations hvcs_ops = { + .install = hvcs_install, + .open = hvcs_open, + .close = hvcs_close, + .cleanup = hvcs_cleanup, + .hangup = hvcs_hangup, + .write = hvcs_write, + .write_room = hvcs_write_room, + .chars_in_buffer = hvcs_chars_in_buffer, + .unthrottle = hvcs_unthrottle, + .throttle = hvcs_throttle, +}; + +static int hvcs_alloc_index_list(int n) +{ + int i; + + hvcs_index_list = kmalloc_array(n, sizeof(hvcs_index_count), + GFP_KERNEL); + if (!hvcs_index_list) + return -ENOMEM; + hvcs_index_count = n; + for (i = 0; i < hvcs_index_count; i++) + hvcs_index_list[i] = -1; + return 0; +} + +static void hvcs_free_index_list(void) +{ + /* Paranoia check to be thorough. */ + kfree(hvcs_index_list); + hvcs_index_list = NULL; + hvcs_index_count = 0; +} + +static int hvcs_initialize(void) +{ + int rc, num_ttys_to_alloc; + + mutex_lock(&hvcs_init_mutex); + if (hvcs_task) { + mutex_unlock(&hvcs_init_mutex); + return 0; + } + + /* Has the user specified an overload with an insmod param? */ + if (hvcs_parm_num_devs <= 0 || + (hvcs_parm_num_devs > HVCS_MAX_SERVER_ADAPTERS)) { + num_ttys_to_alloc = HVCS_DEFAULT_SERVER_ADAPTERS; + } else + num_ttys_to_alloc = hvcs_parm_num_devs; + + hvcs_tty_driver = tty_alloc_driver(num_ttys_to_alloc, + TTY_DRIVER_REAL_RAW); + if (IS_ERR(hvcs_tty_driver)) { + mutex_unlock(&hvcs_init_mutex); + return PTR_ERR(hvcs_tty_driver); + } + + if (hvcs_alloc_index_list(num_ttys_to_alloc)) { + rc = -ENOMEM; + goto index_fail; + } + + hvcs_tty_driver->driver_name = hvcs_driver_name; + hvcs_tty_driver->name = hvcs_device_node; + + /* + * We'll let the system assign us a major number, indicated by leaving + * it blank. + */ + + hvcs_tty_driver->minor_start = HVCS_MINOR_START; + hvcs_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; + + /* + * We role our own so that we DONT ECHO. We can't echo because the + * device we are connecting to already echoes by default and this would + * throw us into a horrible recursive echo-echo-echo loop. + */ + hvcs_tty_driver->init_termios = hvcs_tty_termios; + + tty_set_operations(hvcs_tty_driver, &hvcs_ops); + + /* + * The following call will result in sysfs entries that denote the + * dynamically assigned major and minor numbers for our devices. + */ + if (tty_register_driver(hvcs_tty_driver)) { + printk(KERN_ERR "HVCS: registration as a tty driver failed.\n"); + rc = -EIO; + goto register_fail; + } + + hvcs_pi_buff = (unsigned long *) __get_free_page(GFP_KERNEL); + if (!hvcs_pi_buff) { + rc = -ENOMEM; + goto buff_alloc_fail; + } + + hvcs_task = kthread_run(khvcsd, NULL, "khvcsd"); + if (IS_ERR(hvcs_task)) { + printk(KERN_ERR "HVCS: khvcsd creation failed.\n"); + rc = -EIO; + goto kthread_fail; + } + mutex_unlock(&hvcs_init_mutex); + return 0; + +kthread_fail: + free_page((unsigned long)hvcs_pi_buff); +buff_alloc_fail: + tty_unregister_driver(hvcs_tty_driver); +register_fail: + hvcs_free_index_list(); +index_fail: + tty_driver_kref_put(hvcs_tty_driver); + hvcs_tty_driver = NULL; + mutex_unlock(&hvcs_init_mutex); + return rc; +} + +static int __init hvcs_module_init(void) +{ + int rc = vio_register_driver(&hvcs_vio_driver); + if (rc) { + printk(KERN_ERR "HVCS: can't register vio driver\n"); + return rc; + } + + pr_info("HVCS: Driver registered.\n"); + + /* This needs to be done AFTER the vio_register_driver() call or else + * the kobjects won't be initialized properly. + */ + rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan); + if (rc) + pr_warn("HVCS: Failed to create rescan file (err %d)\n", rc); + + return 0; +} + +static void __exit hvcs_module_exit(void) +{ + /* + * This driver receives hvcs_remove callbacks for each device upon + * module removal. + */ + vio_unregister_driver(&hvcs_vio_driver); + if (!hvcs_task) + return; + + /* + * This synchronous operation will wake the khvcsd kthread if it is + * asleep and will return when khvcsd has terminated. + */ + kthread_stop(hvcs_task); + + spin_lock(&hvcs_pi_lock); + free_page((unsigned long)hvcs_pi_buff); + hvcs_pi_buff = NULL; + spin_unlock(&hvcs_pi_lock); + + driver_remove_file(&hvcs_vio_driver.driver, &driver_attr_rescan); + + tty_unregister_driver(hvcs_tty_driver); + + hvcs_free_index_list(); + + tty_driver_kref_put(hvcs_tty_driver); + + printk(KERN_INFO "HVCS: driver module removed.\n"); +} + +module_init(hvcs_module_init); +module_exit(hvcs_module_exit); diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c new file mode 100644 index 000000000..a200d01ec --- /dev/null +++ b/drivers/tty/hvc/hvsi.c @@ -0,0 +1,1225 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM + */ + +/* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS + * and the service processor on IBM pSeries servers. On these servers, there + * are no serial ports under the OS's control, and sometimes there is no other + * console available either. However, the service processor has two standard + * serial ports, so this over-complicated protocol allows the OS to control + * those ports by proxy. + * + * Besides data, the procotol supports the reading/writing of the serial + * port's DTR line, and the reading of the CD line. This is to allow the OS to + * control a modem attached to the service processor's serial port. Note that + * the OS cannot change the speed of the port through this protocol. + */ + +#undef DEBUG + +#include <linux/console.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/major.h> +#include <linux/kernel.h> +#include <linux/of_irq.h> +#include <linux/spinlock.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <asm/hvcall.h> +#include <asm/hvconsole.h> +#include <linux/uaccess.h> +#include <asm/vio.h> +#include <asm/param.h> +#include <asm/hvsi.h> + +#define HVSI_MAJOR 229 +#define HVSI_MINOR 128 +#define MAX_NR_HVSI_CONSOLES 4 + +#define HVSI_TIMEOUT (5*HZ) +#define HVSI_VERSION 1 +#define HVSI_MAX_PACKET 256 +#define HVSI_MAX_READ 16 +#define HVSI_MAX_OUTGOING_DATA 12 +#define N_OUTBUF 12 + +/* + * we pass data via two 8-byte registers, so we would like our char arrays + * properly aligned for those loads. + */ +#define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) + +struct hvsi_struct { + struct tty_port port; + struct delayed_work writer; + struct work_struct handshaker; + wait_queue_head_t emptyq; /* woken when outbuf is emptied */ + wait_queue_head_t stateq; /* woken when HVSI state changes */ + spinlock_t lock; + int index; + uint8_t throttle_buf[128]; + uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */ + /* inbuf is for packet reassembly. leave a little room for leftovers. */ + uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ]; + uint8_t *inbuf_end; + int n_throttle; + int n_outbuf; + uint32_t vtermno; + uint32_t virq; + atomic_t seqno; /* HVSI packet sequence number */ + uint16_t mctrl; + uint8_t state; /* HVSI protocol state */ + uint8_t flags; +#ifdef CONFIG_MAGIC_SYSRQ + uint8_t sysrq; +#endif /* CONFIG_MAGIC_SYSRQ */ +}; +static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES]; + +static struct tty_driver *hvsi_driver; +static int hvsi_count; +static int (*hvsi_wait)(struct hvsi_struct *hp, int state); + +enum HVSI_PROTOCOL_STATE { + HVSI_CLOSED, + HVSI_WAIT_FOR_VER_RESPONSE, + HVSI_WAIT_FOR_VER_QUERY, + HVSI_OPEN, + HVSI_WAIT_FOR_MCTRL_RESPONSE, + HVSI_FSP_DIED, +}; +#define HVSI_CONSOLE 0x1 + +static inline int is_console(struct hvsi_struct *hp) +{ + return hp->flags & HVSI_CONSOLE; +} + +static inline int is_open(struct hvsi_struct *hp) +{ + /* if we're waiting for an mctrl then we're already open */ + return (hp->state == HVSI_OPEN) + || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE); +} + +static inline void print_state(struct hvsi_struct *hp) +{ +#ifdef DEBUG + static const char *state_names[] = { + "HVSI_CLOSED", + "HVSI_WAIT_FOR_VER_RESPONSE", + "HVSI_WAIT_FOR_VER_QUERY", + "HVSI_OPEN", + "HVSI_WAIT_FOR_MCTRL_RESPONSE", + "HVSI_FSP_DIED", + }; + const char *name = (hp->state < ARRAY_SIZE(state_names)) + ? state_names[hp->state] : "UNKNOWN"; + + pr_debug("hvsi%i: state = %s\n", hp->index, name); +#endif /* DEBUG */ +} + +static inline void __set_state(struct hvsi_struct *hp, int state) +{ + hp->state = state; + print_state(hp); + wake_up_all(&hp->stateq); +} + +static inline void set_state(struct hvsi_struct *hp, int state) +{ + unsigned long flags; + + spin_lock_irqsave(&hp->lock, flags); + __set_state(hp, state); + spin_unlock_irqrestore(&hp->lock, flags); +} + +static inline int len_packet(const uint8_t *packet) +{ + return (int)((struct hvsi_header *)packet)->len; +} + +static inline int is_header(const uint8_t *packet) +{ + struct hvsi_header *header = (struct hvsi_header *)packet; + return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER; +} + +static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet) +{ + if (hp->inbuf_end < packet + sizeof(struct hvsi_header)) + return 0; /* don't even have the packet header */ + + if (hp->inbuf_end < (packet + len_packet(packet))) + return 0; /* don't have the rest of the packet */ + + return 1; +} + +/* shift remaining bytes in packetbuf down */ +static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to) +{ + int remaining = (int)(hp->inbuf_end - read_to); + + pr_debug("%s: %i chars remain\n", __func__, remaining); + + if (read_to != hp->inbuf) + memmove(hp->inbuf, read_to, remaining); + + hp->inbuf_end = hp->inbuf + remaining; +} + +#ifdef DEBUG +#define dbg_dump_packet(packet) dump_packet(packet) +#define dbg_dump_hex(data, len) dump_hex(data, len) +#else +#define dbg_dump_packet(packet) do { } while (0) +#define dbg_dump_hex(data, len) do { } while (0) +#endif + +static void dump_hex(const uint8_t *data, int len) +{ + int i; + + printk(" "); + for (i=0; i < len; i++) + printk("%.2x", data[i]); + + printk("\n "); + for (i=0; i < len; i++) { + if (isprint(data[i])) + printk("%c", data[i]); + else + printk("."); + } + printk("\n"); +} + +static void dump_packet(uint8_t *packet) +{ + struct hvsi_header *header = (struct hvsi_header *)packet; + + printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len, + header->seqno); + + dump_hex(packet, header->len); +} + +static int hvsi_read(struct hvsi_struct *hp, char *buf, int count) +{ + unsigned long got; + + got = hvc_get_chars(hp->vtermno, buf, count); + + return got; +} + +static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet, + struct tty_struct *tty, struct hvsi_struct **to_handshake) +{ + struct hvsi_control *header = (struct hvsi_control *)packet; + + switch (be16_to_cpu(header->verb)) { + case VSV_MODEM_CTL_UPDATE: + if ((be32_to_cpu(header->word) & HVSI_TSCD) == 0) { + /* CD went away; no more connection */ + pr_debug("hvsi%i: CD dropped\n", hp->index); + hp->mctrl &= TIOCM_CD; + if (tty && !C_CLOCAL(tty)) + tty_hangup(tty); + } + break; + case VSV_CLOSE_PROTOCOL: + pr_debug("hvsi%i: service processor came back\n", hp->index); + if (hp->state != HVSI_CLOSED) { + *to_handshake = hp; + } + break; + default: + printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ", + hp->index); + dump_packet(packet); + break; + } +} + +static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet) +{ + struct hvsi_query_response *resp = (struct hvsi_query_response *)packet; + uint32_t mctrl_word; + + switch (hp->state) { + case HVSI_WAIT_FOR_VER_RESPONSE: + __set_state(hp, HVSI_WAIT_FOR_VER_QUERY); + break; + case HVSI_WAIT_FOR_MCTRL_RESPONSE: + hp->mctrl = 0; + mctrl_word = be32_to_cpu(resp->u.mctrl_word); + if (mctrl_word & HVSI_TSDTR) + hp->mctrl |= TIOCM_DTR; + if (mctrl_word & HVSI_TSCD) + hp->mctrl |= TIOCM_CD; + __set_state(hp, HVSI_OPEN); + break; + default: + printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index); + dump_packet(packet); + break; + } +} + +/* respond to service processor's version query */ +static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno) +{ + struct hvsi_query_response packet __ALIGNED__; + int wrote; + + packet.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER; + packet.hdr.len = sizeof(struct hvsi_query_response); + packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); + packet.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER); + packet.u.version = HVSI_VERSION; + packet.query_seqno = cpu_to_be16(query_seqno+1); + + pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); + dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); + + wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); + if (wrote != packet.hdr.len) { + printk(KERN_ERR "hvsi%i: couldn't send query response!\n", + hp->index); + return -EIO; + } + + return 0; +} + +static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet) +{ + struct hvsi_query *query = (struct hvsi_query *)packet; + + switch (hp->state) { + case HVSI_WAIT_FOR_VER_QUERY: + hvsi_version_respond(hp, be16_to_cpu(query->hdr.seqno)); + __set_state(hp, HVSI_OPEN); + break; + default: + printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index); + dump_packet(packet); + break; + } +} + +static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len) +{ + int i; + + for (i=0; i < len; i++) { + char c = buf[i]; +#ifdef CONFIG_MAGIC_SYSRQ + if (c == '\0') { + hp->sysrq = 1; + continue; + } else if (hp->sysrq) { + handle_sysrq(c); + hp->sysrq = 0; + continue; + } +#endif /* CONFIG_MAGIC_SYSRQ */ + tty_insert_flip_char(&hp->port, c, 0); + } +} + +/* + * We could get 252 bytes of data at once here. But the tty layer only + * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow + * it. Accordingly we won't send more than 128 bytes at a time to the flip + * buffer, which will give the tty buffer a chance to throttle us. Should the + * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be + * revisited. + */ +#define TTY_THRESHOLD_THROTTLE 128 +static bool hvsi_recv_data(struct hvsi_struct *hp, const uint8_t *packet) +{ + const struct hvsi_header *header = (const struct hvsi_header *)packet; + const uint8_t *data = packet + sizeof(struct hvsi_header); + int datalen = header->len - sizeof(struct hvsi_header); + int overflow = datalen - TTY_THRESHOLD_THROTTLE; + + pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data); + + if (datalen == 0) + return false; + + if (overflow > 0) { + pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__); + datalen = TTY_THRESHOLD_THROTTLE; + } + + hvsi_insert_chars(hp, data, datalen); + + if (overflow > 0) { + /* + * we still have more data to deliver, so we need to save off the + * overflow and send it later + */ + pr_debug("%s: deferring overflow\n", __func__); + memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow); + hp->n_throttle = overflow; + } + + return true; +} + +/* + * Returns true/false indicating data successfully read from hypervisor. + * Used both to get packets for tty connections and to advance the state + * machine during console handshaking (in which case tty = NULL and we ignore + * incoming data). + */ +static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct *tty, + struct hvsi_struct **handshake) +{ + uint8_t *packet = hp->inbuf; + int chunklen; + bool flip = false; + + *handshake = NULL; + + chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ); + if (chunklen == 0) { + pr_debug("%s: 0-length read\n", __func__); + return 0; + } + + pr_debug("%s: got %i bytes\n", __func__, chunklen); + dbg_dump_hex(hp->inbuf_end, chunklen); + + hp->inbuf_end += chunklen; + + /* handle all completed packets */ + while ((packet < hp->inbuf_end) && got_packet(hp, packet)) { + struct hvsi_header *header = (struct hvsi_header *)packet; + + if (!is_header(packet)) { + printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index); + /* skip bytes until we find a header or run out of data */ + while ((packet < hp->inbuf_end) && (!is_header(packet))) + packet++; + continue; + } + + pr_debug("%s: handling %i-byte packet\n", __func__, + len_packet(packet)); + dbg_dump_packet(packet); + + switch (header->type) { + case VS_DATA_PACKET_HEADER: + if (!is_open(hp)) + break; + flip = hvsi_recv_data(hp, packet); + break; + case VS_CONTROL_PACKET_HEADER: + hvsi_recv_control(hp, packet, tty, handshake); + break; + case VS_QUERY_RESPONSE_PACKET_HEADER: + hvsi_recv_response(hp, packet); + break; + case VS_QUERY_PACKET_HEADER: + hvsi_recv_query(hp, packet); + break; + default: + printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n", + hp->index, header->type); + dump_packet(packet); + break; + } + + packet += len_packet(packet); + + if (*handshake) { + pr_debug("%s: handshake\n", __func__); + break; + } + } + + compact_inbuf(hp, packet); + + if (flip) + tty_flip_buffer_push(&hp->port); + + return 1; +} + +static void hvsi_send_overflow(struct hvsi_struct *hp) +{ + pr_debug("%s: delivering %i bytes overflow\n", __func__, + hp->n_throttle); + + hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle); + hp->n_throttle = 0; +} + +/* + * must get all pending data because we only get an irq on empty->non-empty + * transition + */ +static irqreturn_t hvsi_interrupt(int irq, void *arg) +{ + struct hvsi_struct *hp = (struct hvsi_struct *)arg; + struct hvsi_struct *handshake; + struct tty_struct *tty; + unsigned long flags; + int again = 1; + + pr_debug("%s\n", __func__); + + tty = tty_port_tty_get(&hp->port); + + while (again) { + spin_lock_irqsave(&hp->lock, flags); + again = hvsi_load_chunk(hp, tty, &handshake); + spin_unlock_irqrestore(&hp->lock, flags); + + if (handshake) { + pr_debug("hvsi%i: attempting re-handshake\n", handshake->index); + schedule_work(&handshake->handshaker); + } + } + + spin_lock_irqsave(&hp->lock, flags); + if (tty && hp->n_throttle && !tty_throttled(tty)) { + /* we weren't hung up and we weren't throttled, so we can + * deliver the rest now */ + hvsi_send_overflow(hp); + tty_flip_buffer_push(&hp->port); + } + spin_unlock_irqrestore(&hp->lock, flags); + + tty_kref_put(tty); + + return IRQ_HANDLED; +} + +/* for boot console, before the irq handler is running */ +static int __init poll_for_state(struct hvsi_struct *hp, int state) +{ + unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; + + for (;;) { + hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */ + + if (hp->state == state) + return 0; + + mdelay(5); + if (time_after(jiffies, end_jiffies)) + return -EIO; + } +} + +/* wait for irq handler to change our state */ +static int wait_for_state(struct hvsi_struct *hp, int state) +{ + int ret = 0; + + if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT)) + ret = -EIO; + + return ret; +} + +static int hvsi_query(struct hvsi_struct *hp, uint16_t verb) +{ + struct hvsi_query packet __ALIGNED__; + int wrote; + + packet.hdr.type = VS_QUERY_PACKET_HEADER; + packet.hdr.len = sizeof(struct hvsi_query); + packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); + packet.verb = cpu_to_be16(verb); + + pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); + dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); + + wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); + if (wrote != packet.hdr.len) { + printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index, + wrote); + return -EIO; + } + + return 0; +} + +static int hvsi_get_mctrl(struct hvsi_struct *hp) +{ + int ret; + + set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE); + hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS); + + ret = hvsi_wait(hp, HVSI_OPEN); + if (ret < 0) { + printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index); + set_state(hp, HVSI_OPEN); + return ret; + } + + pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl); + + return 0; +} + +/* note that we can only set DTR */ +static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl) +{ + struct hvsi_control packet __ALIGNED__; + int wrote; + + packet.hdr.type = VS_CONTROL_PACKET_HEADER; + packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); + packet.hdr.len = sizeof(struct hvsi_control); + packet.verb = cpu_to_be16(VSV_SET_MODEM_CTL); + packet.mask = cpu_to_be32(HVSI_TSDTR); + + if (mctrl & TIOCM_DTR) + packet.word = cpu_to_be32(HVSI_TSDTR); + + pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); + dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); + + wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); + if (wrote != packet.hdr.len) { + printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index); + return -EIO; + } + + return 0; +} + +static void hvsi_drain_input(struct hvsi_struct *hp) +{ + uint8_t buf[HVSI_MAX_READ] __ALIGNED__; + unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; + + while (time_before(end_jiffies, jiffies)) + if (0 == hvsi_read(hp, buf, HVSI_MAX_READ)) + break; +} + +static int hvsi_handshake(struct hvsi_struct *hp) +{ + int ret; + + /* + * We could have a CLOSE or other data waiting for us before we even try + * to open; try to throw it all away so we don't get confused. (CLOSE + * is the first message sent up the pipe when the FSP comes online. We + * need to distinguish between "it came up a while ago and we're the first + * user" and "it was just reset before it saw our handshake packet".) + */ + hvsi_drain_input(hp); + + set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE); + ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER); + if (ret < 0) { + printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index); + return ret; + } + + ret = hvsi_wait(hp, HVSI_OPEN); + if (ret < 0) + return ret; + + return 0; +} + +static void hvsi_handshaker(struct work_struct *work) +{ + struct hvsi_struct *hp = + container_of(work, struct hvsi_struct, handshaker); + + if (hvsi_handshake(hp) >= 0) + return; + + printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index); + if (is_console(hp)) { + /* + * ttys will re-attempt the handshake via hvsi_open, but + * the console will not. + */ + printk(KERN_ERR "hvsi%i: lost console!\n", hp->index); + } +} + +static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count) +{ + struct hvsi_data packet __ALIGNED__; + int ret; + + BUG_ON(count > HVSI_MAX_OUTGOING_DATA); + + packet.hdr.type = VS_DATA_PACKET_HEADER; + packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); + packet.hdr.len = count + sizeof(struct hvsi_header); + memcpy(&packet.data, buf, count); + + ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); + if (ret == packet.hdr.len) { + /* return the number of chars written, not the packet length */ + return count; + } + return ret; /* return any errors */ +} + +static void hvsi_close_protocol(struct hvsi_struct *hp) +{ + struct hvsi_control packet __ALIGNED__; + + packet.hdr.type = VS_CONTROL_PACKET_HEADER; + packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); + packet.hdr.len = 6; + packet.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL); + + pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); + dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); + + hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); +} + +static int hvsi_open(struct tty_struct *tty, struct file *filp) +{ + struct hvsi_struct *hp; + unsigned long flags; + int ret; + + pr_debug("%s\n", __func__); + + hp = &hvsi_ports[tty->index]; + + tty->driver_data = hp; + + mb(); + if (hp->state == HVSI_FSP_DIED) + return -EIO; + + tty_port_tty_set(&hp->port, tty); + spin_lock_irqsave(&hp->lock, flags); + hp->port.count++; + atomic_set(&hp->seqno, 0); + h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); + spin_unlock_irqrestore(&hp->lock, flags); + + if (is_console(hp)) + return 0; /* this has already been handshaked as the console */ + + ret = hvsi_handshake(hp); + if (ret < 0) { + printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name); + return ret; + } + + ret = hvsi_get_mctrl(hp); + if (ret < 0) { + printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name); + return ret; + } + + ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); + if (ret < 0) { + printk(KERN_ERR "%s: couldn't set DTR\n", tty->name); + return ret; + } + + return 0; +} + +/* wait for hvsi_write_worker to empty hp->outbuf */ +static void hvsi_flush_output(struct hvsi_struct *hp) +{ + wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT); + + /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */ + cancel_delayed_work_sync(&hp->writer); + flush_work(&hp->handshaker); + + /* + * it's also possible that our timeout expired and hvsi_write_worker + * didn't manage to push outbuf. poof. + */ + hp->n_outbuf = 0; +} + +static void hvsi_close(struct tty_struct *tty, struct file *filp) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + + pr_debug("%s\n", __func__); + + if (tty_hung_up_p(filp)) + return; + + spin_lock_irqsave(&hp->lock, flags); + + if (--hp->port.count == 0) { + tty_port_tty_set(&hp->port, NULL); + hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */ + + /* only close down connection if it is not the console */ + if (!is_console(hp)) { + h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */ + __set_state(hp, HVSI_CLOSED); + /* + * any data delivered to the tty layer after this will be + * discarded (except for XON/XOFF) + */ + tty->closing = 1; + + spin_unlock_irqrestore(&hp->lock, flags); + + /* let any existing irq handlers finish. no more will start. */ + synchronize_irq(hp->virq); + + /* hvsi_write_worker will re-schedule until outbuf is empty. */ + hvsi_flush_output(hp); + + /* tell FSP to stop sending data */ + hvsi_close_protocol(hp); + + /* + * drain anything FSP is still in the middle of sending, and let + * hvsi_handshake drain the rest on the next open. + */ + hvsi_drain_input(hp); + + spin_lock_irqsave(&hp->lock, flags); + } + } else if (hp->port.count < 0) + printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n", + hp - hvsi_ports, hp->port.count); + + spin_unlock_irqrestore(&hp->lock, flags); +} + +static void hvsi_hangup(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + + pr_debug("%s\n", __func__); + + tty_port_tty_set(&hp->port, NULL); + + spin_lock_irqsave(&hp->lock, flags); + hp->port.count = 0; + hp->n_outbuf = 0; + spin_unlock_irqrestore(&hp->lock, flags); +} + +/* called with hp->lock held */ +static void hvsi_push(struct hvsi_struct *hp) +{ + int n; + + if (hp->n_outbuf <= 0) + return; + + n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf); + if (n > 0) { + /* success */ + pr_debug("%s: wrote %i chars\n", __func__, n); + hp->n_outbuf = 0; + } else if (n == -EIO) { + __set_state(hp, HVSI_FSP_DIED); + printk(KERN_ERR "hvsi%i: service processor died\n", hp->index); + } +} + +/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */ +static void hvsi_write_worker(struct work_struct *work) +{ + struct hvsi_struct *hp = + container_of(work, struct hvsi_struct, writer.work); + unsigned long flags; +#ifdef DEBUG + static long start_j = 0; + + if (start_j == 0) + start_j = jiffies; +#endif /* DEBUG */ + + spin_lock_irqsave(&hp->lock, flags); + + pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); + + if (!is_open(hp)) { + /* + * We could have a non-open connection if the service processor died + * while we were busily scheduling ourselves. In that case, it could + * be minutes before the service processor comes back, so only try + * again once a second. + */ + schedule_delayed_work(&hp->writer, HZ); + goto out; + } + + hvsi_push(hp); + if (hp->n_outbuf > 0) + schedule_delayed_work(&hp->writer, 10); + else { +#ifdef DEBUG + pr_debug("%s: outbuf emptied after %li jiffies\n", __func__, + jiffies - start_j); + start_j = 0; +#endif /* DEBUG */ + wake_up_all(&hp->emptyq); + tty_port_tty_wakeup(&hp->port); + } + +out: + spin_unlock_irqrestore(&hp->lock, flags); +} + +static unsigned int hvsi_write_room(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + + return N_OUTBUF - hp->n_outbuf; +} + +static unsigned int hvsi_chars_in_buffer(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + + return hp->n_outbuf; +} + +static int hvsi_write(struct tty_struct *tty, + const unsigned char *buf, int count) +{ + struct hvsi_struct *hp = tty->driver_data; + const char *source = buf; + unsigned long flags; + int total = 0; + int origcount = count; + + spin_lock_irqsave(&hp->lock, flags); + + pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); + + if (!is_open(hp)) { + /* we're either closing or not yet open; don't accept data */ + pr_debug("%s: not open\n", __func__); + goto out; + } + + /* + * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf + * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls + * will see there is no room in outbuf and return. + */ + while ((count > 0) && (hvsi_write_room(tty) > 0)) { + int chunksize = min_t(int, count, hvsi_write_room(tty)); + + BUG_ON(hp->n_outbuf < 0); + memcpy(hp->outbuf + hp->n_outbuf, source, chunksize); + hp->n_outbuf += chunksize; + + total += chunksize; + source += chunksize; + count -= chunksize; + hvsi_push(hp); + } + + if (hp->n_outbuf > 0) { + /* + * we weren't able to write it all to the hypervisor. + * schedule another push attempt. + */ + schedule_delayed_work(&hp->writer, 10); + } + +out: + spin_unlock_irqrestore(&hp->lock, flags); + + if (total != origcount) + pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount, + total); + + return total; +} + +/* + * I have never seen throttle or unthrottle called, so this little throttle + * buffering scheme may or may not work. + */ +static void hvsi_throttle(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + + pr_debug("%s\n", __func__); + + h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); +} + +static void hvsi_unthrottle(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + + pr_debug("%s\n", __func__); + + spin_lock_irqsave(&hp->lock, flags); + if (hp->n_throttle) { + hvsi_send_overflow(hp); + tty_flip_buffer_push(&hp->port); + } + spin_unlock_irqrestore(&hp->lock, flags); + + + h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); +} + +static int hvsi_tiocmget(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + + hvsi_get_mctrl(hp); + return hp->mctrl; +} + +static int hvsi_tiocmset(struct tty_struct *tty, + unsigned int set, unsigned int clear) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + uint16_t new_mctrl; + + /* we can only alter DTR */ + clear &= TIOCM_DTR; + set &= TIOCM_DTR; + + spin_lock_irqsave(&hp->lock, flags); + + new_mctrl = (hp->mctrl & ~clear) | set; + + if (hp->mctrl != new_mctrl) { + hvsi_set_mctrl(hp, new_mctrl); + hp->mctrl = new_mctrl; + } + spin_unlock_irqrestore(&hp->lock, flags); + + return 0; +} + + +static const struct tty_operations hvsi_ops = { + .open = hvsi_open, + .close = hvsi_close, + .write = hvsi_write, + .hangup = hvsi_hangup, + .write_room = hvsi_write_room, + .chars_in_buffer = hvsi_chars_in_buffer, + .throttle = hvsi_throttle, + .unthrottle = hvsi_unthrottle, + .tiocmget = hvsi_tiocmget, + .tiocmset = hvsi_tiocmset, +}; + +static int __init hvsi_init(void) +{ + struct tty_driver *driver; + int i, ret; + + driver = tty_alloc_driver(hvsi_count, TTY_DRIVER_REAL_RAW); + if (IS_ERR(driver)) + return PTR_ERR(driver); + + driver->driver_name = "hvsi"; + driver->name = "hvsi"; + driver->major = HVSI_MAJOR; + driver->minor_start = HVSI_MINOR; + driver->type = TTY_DRIVER_TYPE_SYSTEM; + driver->init_termios = tty_std_termios; + driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL; + driver->init_termios.c_ispeed = 9600; + driver->init_termios.c_ospeed = 9600; + tty_set_operations(driver, &hvsi_ops); + + for (i=0; i < hvsi_count; i++) { + struct hvsi_struct *hp = &hvsi_ports[i]; + int ret = 1; + + tty_port_link_device(&hp->port, driver, i); + + ret = request_irq(hp->virq, hvsi_interrupt, 0, "hvsi", hp); + if (ret) + printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n", + hp->virq, ret); + } + hvsi_wait = wait_for_state; /* irqs active now */ + + ret = tty_register_driver(driver); + if (ret) { + pr_err("Couldn't register hvsi console driver\n"); + goto err_free_irq; + } + + hvsi_driver = driver; + + printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); + + return 0; +err_free_irq: + hvsi_wait = poll_for_state; + for (i = 0; i < hvsi_count; i++) { + struct hvsi_struct *hp = &hvsi_ports[i]; + + free_irq(hp->virq, hp); + } + tty_driver_kref_put(driver); + + return ret; +} +device_initcall(hvsi_init); + +/***** console (not tty) code: *****/ + +static void hvsi_console_print(struct console *console, const char *buf, + unsigned int count) +{ + struct hvsi_struct *hp = &hvsi_ports[console->index]; + char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__; + unsigned int i = 0, n = 0; + int ret, donecr = 0; + + mb(); + if (!is_open(hp)) + return; + + /* + * ugh, we have to translate LF -> CRLF ourselves, in place. + * copied from hvc_console.c: + */ + while (count > 0 || i > 0) { + if (count > 0 && i < sizeof(c)) { + if (buf[n] == '\n' && !donecr) { + c[i++] = '\r'; + donecr = 1; + } else { + c[i++] = buf[n++]; + donecr = 0; + --count; + } + } else { + ret = hvsi_put_chars(hp, c, i); + if (ret < 0) + i = 0; + i -= ret; + } + } +} + +static struct tty_driver *hvsi_console_device(struct console *console, + int *index) +{ + *index = console->index; + return hvsi_driver; +} + +static int __init hvsi_console_setup(struct console *console, char *options) +{ + struct hvsi_struct *hp; + int ret; + + if (console->index < 0 || console->index >= hvsi_count) + return -EINVAL; + hp = &hvsi_ports[console->index]; + + /* give the FSP a chance to change the baud rate when we re-open */ + hvsi_close_protocol(hp); + + ret = hvsi_handshake(hp); + if (ret < 0) + return ret; + + ret = hvsi_get_mctrl(hp); + if (ret < 0) + return ret; + + ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); + if (ret < 0) + return ret; + + hp->flags |= HVSI_CONSOLE; + + return 0; +} + +static struct console hvsi_console = { + .name = "hvsi", + .write = hvsi_console_print, + .device = hvsi_console_device, + .setup = hvsi_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +static int __init hvsi_console_init(void) +{ + struct device_node *vty; + + hvsi_wait = poll_for_state; /* no irqs yet; must poll */ + + /* search device tree for vty nodes */ + for_each_compatible_node(vty, "serial", "hvterm-protocol") { + struct hvsi_struct *hp; + const __be32 *vtermno, *irq; + + vtermno = of_get_property(vty, "reg", NULL); + irq = of_get_property(vty, "interrupts", NULL); + if (!vtermno || !irq) + continue; + + if (hvsi_count >= MAX_NR_HVSI_CONSOLES) { + of_node_put(vty); + break; + } + + hp = &hvsi_ports[hvsi_count]; + INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker); + INIT_WORK(&hp->handshaker, hvsi_handshaker); + init_waitqueue_head(&hp->emptyq); + init_waitqueue_head(&hp->stateq); + spin_lock_init(&hp->lock); + tty_port_init(&hp->port); + hp->index = hvsi_count; + hp->inbuf_end = hp->inbuf; + hp->state = HVSI_CLOSED; + hp->vtermno = be32_to_cpup(vtermno); + hp->virq = irq_create_mapping(NULL, be32_to_cpup(irq)); + if (hp->virq == 0) { + printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n", + __func__, be32_to_cpup(irq)); + tty_port_destroy(&hp->port); + continue; + } + + hvsi_count++; + } + + if (hvsi_count) + register_console(&hvsi_console); + return 0; +} +console_initcall(hvsi_console_init); diff --git a/drivers/tty/hvc/hvsi_lib.c b/drivers/tty/hvc/hvsi_lib.c new file mode 100644 index 000000000..09289c815 --- /dev/null +++ b/drivers/tty/hvc/hvsi_lib.c @@ -0,0 +1,424 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/types.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/console.h> +#include <asm/hvsi.h> + +#include "hvc_console.h" + +static int hvsi_send_packet(struct hvsi_priv *pv, struct hvsi_header *packet) +{ + packet->seqno = cpu_to_be16(atomic_inc_return(&pv->seqno)); + + /* Assumes that always succeeds, works in practice */ + return pv->put_chars(pv->termno, (char *)packet, packet->len); +} + +static void hvsi_start_handshake(struct hvsi_priv *pv) +{ + struct hvsi_query q; + + /* Reset state */ + pv->established = 0; + atomic_set(&pv->seqno, 0); + + pr_devel("HVSI@%x: Handshaking started\n", pv->termno); + + /* Send version query */ + q.hdr.type = VS_QUERY_PACKET_HEADER; + q.hdr.len = sizeof(struct hvsi_query); + q.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER); + hvsi_send_packet(pv, &q.hdr); +} + +static int hvsi_send_close(struct hvsi_priv *pv) +{ + struct hvsi_control ctrl; + + pv->established = 0; + + ctrl.hdr.type = VS_CONTROL_PACKET_HEADER; + ctrl.hdr.len = sizeof(struct hvsi_control); + ctrl.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL); + return hvsi_send_packet(pv, &ctrl.hdr); +} + +static void hvsi_cd_change(struct hvsi_priv *pv, int cd) +{ + if (cd) + pv->mctrl |= TIOCM_CD; + else { + pv->mctrl &= ~TIOCM_CD; + + /* We copy the existing hvsi driver semantics + * here which are to trigger a hangup when + * we get a carrier loss. + * Closing our connection to the server will + * do just that. + */ + if (!pv->is_console && pv->opened) { + pr_devel("HVSI@%x Carrier lost, hanging up !\n", + pv->termno); + hvsi_send_close(pv); + } + } +} + +static void hvsi_got_control(struct hvsi_priv *pv) +{ + struct hvsi_control *pkt = (struct hvsi_control *)pv->inbuf; + + switch (be16_to_cpu(pkt->verb)) { + case VSV_CLOSE_PROTOCOL: + /* We restart the handshaking */ + hvsi_start_handshake(pv); + break; + case VSV_MODEM_CTL_UPDATE: + /* Transition of carrier detect */ + hvsi_cd_change(pv, be32_to_cpu(pkt->word) & HVSI_TSCD); + break; + } +} + +static void hvsi_got_query(struct hvsi_priv *pv) +{ + struct hvsi_query *pkt = (struct hvsi_query *)pv->inbuf; + struct hvsi_query_response r; + + /* We only handle version queries */ + if (be16_to_cpu(pkt->verb) != VSV_SEND_VERSION_NUMBER) + return; + + pr_devel("HVSI@%x: Got version query, sending response...\n", + pv->termno); + + /* Send version response */ + r.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER; + r.hdr.len = sizeof(struct hvsi_query_response); + r.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER); + r.u.version = HVSI_VERSION; + r.query_seqno = pkt->hdr.seqno; + hvsi_send_packet(pv, &r.hdr); + + /* Assume protocol is open now */ + pv->established = 1; +} + +static void hvsi_got_response(struct hvsi_priv *pv) +{ + struct hvsi_query_response *r = + (struct hvsi_query_response *)pv->inbuf; + + switch(r->verb) { + case VSV_SEND_MODEM_CTL_STATUS: + hvsi_cd_change(pv, be32_to_cpu(r->u.mctrl_word) & HVSI_TSCD); + pv->mctrl_update = 1; + break; + } +} + +static int hvsi_check_packet(struct hvsi_priv *pv) +{ + u8 len, type; + + /* Check header validity. If it's invalid, we ditch + * the whole buffer and hope we eventually resync + */ + if (pv->inbuf[0] < 0xfc) { + pv->inbuf_len = pv->inbuf_pktlen = 0; + return 0; + } + type = pv->inbuf[0]; + len = pv->inbuf[1]; + + /* Packet incomplete ? */ + if (pv->inbuf_len < len) + return 0; + + pr_devel("HVSI@%x: Got packet type %x len %d bytes:\n", + pv->termno, type, len); + + /* We have a packet, yay ! Handle it */ + switch(type) { + case VS_DATA_PACKET_HEADER: + pv->inbuf_pktlen = len - 4; + pv->inbuf_cur = 4; + return 1; + case VS_CONTROL_PACKET_HEADER: + hvsi_got_control(pv); + break; + case VS_QUERY_PACKET_HEADER: + hvsi_got_query(pv); + break; + case VS_QUERY_RESPONSE_PACKET_HEADER: + hvsi_got_response(pv); + break; + } + + /* Swallow packet and retry */ + pv->inbuf_len -= len; + memmove(pv->inbuf, &pv->inbuf[len], pv->inbuf_len); + return 1; +} + +static int hvsi_get_packet(struct hvsi_priv *pv) +{ + /* If we have room in the buffer, ask HV for more */ + if (pv->inbuf_len < HVSI_INBUF_SIZE) + pv->inbuf_len += pv->get_chars(pv->termno, + &pv->inbuf[pv->inbuf_len], + HVSI_INBUF_SIZE - pv->inbuf_len); + /* + * If we have at least 4 bytes in the buffer, check for + * a full packet and retry + */ + if (pv->inbuf_len >= 4) + return hvsi_check_packet(pv); + return 0; +} + +int hvsilib_get_chars(struct hvsi_priv *pv, char *buf, int count) +{ + unsigned int tries, read = 0; + + if (WARN_ON(!pv)) + return -ENXIO; + + /* If we aren't open, don't do anything in order to avoid races + * with connection establishment. The hvc core will call this + * before we have returned from notifier_add(), and we need to + * avoid multiple users playing with the receive buffer + */ + if (!pv->opened) + return 0; + + /* We try twice, once with what data we have and once more + * after we try to fetch some more from the hypervisor + */ + for (tries = 1; count && tries < 2; tries++) { + /* Consume existing data packet */ + if (pv->inbuf_pktlen) { + unsigned int l = min(count, (int)pv->inbuf_pktlen); + memcpy(&buf[read], &pv->inbuf[pv->inbuf_cur], l); + pv->inbuf_cur += l; + pv->inbuf_pktlen -= l; + count -= l; + read += l; + } + if (count == 0) + break; + + /* Data packet fully consumed, move down remaning data */ + if (pv->inbuf_cur) { + pv->inbuf_len -= pv->inbuf_cur; + memmove(pv->inbuf, &pv->inbuf[pv->inbuf_cur], + pv->inbuf_len); + pv->inbuf_cur = 0; + } + + /* Try to get another packet */ + if (hvsi_get_packet(pv)) + tries--; + } + if (!pv->established) { + pr_devel("HVSI@%x: returning -EPIPE\n", pv->termno); + return -EPIPE; + } + return read; +} + +int hvsilib_put_chars(struct hvsi_priv *pv, const char *buf, int count) +{ + struct hvsi_data dp; + int rc, adjcount = min(count, HVSI_MAX_OUTGOING_DATA); + + if (WARN_ON(!pv)) + return -ENODEV; + + dp.hdr.type = VS_DATA_PACKET_HEADER; + dp.hdr.len = adjcount + sizeof(struct hvsi_header); + memcpy(dp.data, buf, adjcount); + rc = hvsi_send_packet(pv, &dp.hdr); + if (rc <= 0) + return rc; + return adjcount; +} + +static void maybe_msleep(unsigned long ms) +{ + /* During early boot, IRQs are disabled, use mdelay */ + if (irqs_disabled()) + mdelay(ms); + else + msleep(ms); +} + +int hvsilib_read_mctrl(struct hvsi_priv *pv) +{ + struct hvsi_query q; + int rc, timeout; + + pr_devel("HVSI@%x: Querying modem control status...\n", + pv->termno); + + pv->mctrl_update = 0; + q.hdr.type = VS_QUERY_PACKET_HEADER; + q.hdr.len = sizeof(struct hvsi_query); + q.verb = cpu_to_be16(VSV_SEND_MODEM_CTL_STATUS); + rc = hvsi_send_packet(pv, &q.hdr); + if (rc <= 0) { + pr_devel("HVSI@%x: Error %d...\n", pv->termno, rc); + return rc; + } + + /* Try for up to 200ms */ + for (timeout = 0; timeout < 20; timeout++) { + if (!pv->established) + return -ENXIO; + if (pv->mctrl_update) + return 0; + if (!hvsi_get_packet(pv)) + maybe_msleep(10); + } + return -EIO; +} + +int hvsilib_write_mctrl(struct hvsi_priv *pv, int dtr) +{ + struct hvsi_control ctrl; + unsigned short mctrl; + + mctrl = pv->mctrl; + if (dtr) + mctrl |= TIOCM_DTR; + else + mctrl &= ~TIOCM_DTR; + if (mctrl == pv->mctrl) + return 0; + pv->mctrl = mctrl; + + pr_devel("HVSI@%x: %s DTR...\n", pv->termno, + dtr ? "Setting" : "Clearing"); + + ctrl.hdr.type = VS_CONTROL_PACKET_HEADER, + ctrl.hdr.len = sizeof(struct hvsi_control); + ctrl.verb = cpu_to_be16(VSV_SET_MODEM_CTL); + ctrl.mask = cpu_to_be32(HVSI_TSDTR); + ctrl.word = cpu_to_be32(dtr ? HVSI_TSDTR : 0); + return hvsi_send_packet(pv, &ctrl.hdr); +} + +void hvsilib_establish(struct hvsi_priv *pv) +{ + int timeout; + + pr_devel("HVSI@%x: Establishing...\n", pv->termno); + + /* Try for up to 200ms, there can be a packet to + * start the process waiting for us... + */ + for (timeout = 0; timeout < 20; timeout++) { + if (pv->established) + goto established; + if (!hvsi_get_packet(pv)) + maybe_msleep(10); + } + + /* Failed, send a close connection packet just + * in case + */ + pr_devel("HVSI@%x: ... sending close\n", pv->termno); + + hvsi_send_close(pv); + + /* Then restart handshake */ + + pr_devel("HVSI@%x: ... restarting handshake\n", pv->termno); + + hvsi_start_handshake(pv); + + pr_devel("HVSI@%x: ... waiting handshake\n", pv->termno); + + /* Try for up to 400ms */ + for (timeout = 0; timeout < 40; timeout++) { + if (pv->established) + goto established; + if (!hvsi_get_packet(pv)) + maybe_msleep(10); + } + + if (!pv->established) { + pr_devel("HVSI@%x: Timeout handshaking, giving up !\n", + pv->termno); + return; + } + established: + /* Query modem control lines */ + + pr_devel("HVSI@%x: ... established, reading mctrl\n", pv->termno); + + hvsilib_read_mctrl(pv); + + /* Set our own DTR */ + + pr_devel("HVSI@%x: ... setting mctrl\n", pv->termno); + + hvsilib_write_mctrl(pv, 1); + + /* Set the opened flag so reads are allowed */ + wmb(); + pv->opened = 1; +} + +int hvsilib_open(struct hvsi_priv *pv, struct hvc_struct *hp) +{ + pr_devel("HVSI@%x: open !\n", pv->termno); + + /* Keep track of the tty data structure */ + pv->tty = tty_port_tty_get(&hp->port); + + hvsilib_establish(pv); + + return 0; +} + +void hvsilib_close(struct hvsi_priv *pv, struct hvc_struct *hp) +{ + unsigned long flags; + + pr_devel("HVSI@%x: close !\n", pv->termno); + + if (!pv->is_console) { + pr_devel("HVSI@%x: Not a console, tearing down\n", + pv->termno); + + /* Clear opened, synchronize with khvcd */ + spin_lock_irqsave(&hp->lock, flags); + pv->opened = 0; + spin_unlock_irqrestore(&hp->lock, flags); + + /* Clear our own DTR */ + if (!pv->tty || (pv->tty->termios.c_cflag & HUPCL)) + hvsilib_write_mctrl(pv, 0); + + /* Tear down the connection */ + hvsi_send_close(pv); + } + + tty_kref_put(pv->tty); + pv->tty = NULL; +} + +void hvsilib_init(struct hvsi_priv *pv, + int (*get_chars)(uint32_t termno, char *buf, int count), + int (*put_chars)(uint32_t termno, const char *buf, + int count), + int termno, int is_console) +{ + memset(pv, 0, sizeof(*pv)); + pv->get_chars = get_chars; + pv->put_chars = put_chars; + pv->termno = termno; + pv->is_console = is_console; +} |