From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- drivers/tty/hvc/hvc_vio.c | 482 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 482 insertions(+) create mode 100644 drivers/tty/hvc/hvc_vio.c (limited to 'drivers/tty/hvc/hvc_vio.c') diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c new file mode 100644 index 000000000..80fd06fbd --- /dev/null +++ b/drivers/tty/hvc/hvc_vio.c @@ -0,0 +1,482 @@ +// 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 , IBM + * Copyright (C) 2001 Paul Mackerras , IBM + * Copyright (C) 2004 Benjamin Herrenschmidt , IBM Corp. + * Copyright (C) 2004 IBM Corporation + * + * Additional Author(s): + * Ryan S. Arnold + * + * TODO: + * + * - handle error in sending hvsi protocol packets + * - retry nego on subsequent sends ? + */ + +#undef DEBUG + +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#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); +} + +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); +} + +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 char *name; + const struct hv_ops *ops; + + /* find the boot console from /chosen/stdout */ + if (!of_stdout) + return; + name = of_get_property(of_stdout, "name", NULL); + if (!name) { + printk(KERN_WARNING "stdout node missing 'name' property!\n"); + return; + } + + /* Check if it's a virtual terminal */ + if (strncmp(name, "vty", 3) != 0) + 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 */ -- cgit v1.2.3