diff options
Diffstat (limited to 'drivers/char/snsc.c')
| -rw-r--r-- | drivers/char/snsc.c | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/drivers/char/snsc.c b/drivers/char/snsc.c new file mode 100644 index 000000000..5918ea749 --- /dev/null +++ b/drivers/char/snsc.c @@ -0,0 +1,469 @@ +/* + * SN Platform system controller communication support + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2004, 2006 Silicon Graphics, Inc. All rights reserved. + */ + +/* + * System controller communication driver + * + * This driver allows a user process to communicate with the system + * controller (a.k.a. "IRouter") network in an SGI SN system. + */ + +#include <linux/interrupt.h> +#include <linux/sched/signal.h> +#include <linux/device.h> +#include <linux/poll.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <asm/sn/io.h> +#include <asm/sn/sn_sal.h> +#include <asm/sn/module.h> +#include <asm/sn/geo.h> +#include <asm/sn/nodepda.h> +#include "snsc.h" + +#define SYSCTL_BASENAME "snsc" + +#define SCDRV_BUFSZ 2048 +#define SCDRV_TIMEOUT 1000 + +static DEFINE_MUTEX(scdrv_mutex); +static irqreturn_t +scdrv_interrupt(int irq, void *subch_data) +{ + struct subch_data_s *sd = subch_data; + unsigned long flags; + int status; + + spin_lock_irqsave(&sd->sd_rlock, flags); + spin_lock(&sd->sd_wlock); + status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch); + + if (status > 0) { + if (status & SAL_IROUTER_INTR_RECV) { + wake_up(&sd->sd_rq); + } + if (status & SAL_IROUTER_INTR_XMIT) { + ia64_sn_irtr_intr_disable + (sd->sd_nasid, sd->sd_subch, + SAL_IROUTER_INTR_XMIT); + wake_up(&sd->sd_wq); + } + } + spin_unlock(&sd->sd_wlock); + spin_unlock_irqrestore(&sd->sd_rlock, flags); + return IRQ_HANDLED; +} + +/* + * scdrv_open + * + * Reserve a subchannel for system controller communication. + */ + +static int +scdrv_open(struct inode *inode, struct file *file) +{ + struct sysctl_data_s *scd; + struct subch_data_s *sd; + int rv; + + /* look up device info for this device file */ + scd = container_of(inode->i_cdev, struct sysctl_data_s, scd_cdev); + + /* allocate memory for subchannel data */ + sd = kzalloc(sizeof (struct subch_data_s), GFP_KERNEL); + if (sd == NULL) { + printk("%s: couldn't allocate subchannel data\n", + __func__); + return -ENOMEM; + } + + /* initialize subch_data_s fields */ + sd->sd_nasid = scd->scd_nasid; + sd->sd_subch = ia64_sn_irtr_open(scd->scd_nasid); + + if (sd->sd_subch < 0) { + kfree(sd); + printk("%s: couldn't allocate subchannel\n", __func__); + return -EBUSY; + } + + spin_lock_init(&sd->sd_rlock); + spin_lock_init(&sd->sd_wlock); + init_waitqueue_head(&sd->sd_rq); + init_waitqueue_head(&sd->sd_wq); + sema_init(&sd->sd_rbs, 1); + sema_init(&sd->sd_wbs, 1); + + file->private_data = sd; + + /* hook this subchannel up to the system controller interrupt */ + mutex_lock(&scdrv_mutex); + rv = request_irq(SGI_UART_VECTOR, scdrv_interrupt, + IRQF_SHARED, SYSCTL_BASENAME, sd); + if (rv) { + ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch); + kfree(sd); + printk("%s: irq request failed (%d)\n", __func__, rv); + mutex_unlock(&scdrv_mutex); + return -EBUSY; + } + mutex_unlock(&scdrv_mutex); + return 0; +} + +/* + * scdrv_release + * + * Release a previously-reserved subchannel. + */ + +static int +scdrv_release(struct inode *inode, struct file *file) +{ + struct subch_data_s *sd = (struct subch_data_s *) file->private_data; + int rv; + + /* free the interrupt */ + free_irq(SGI_UART_VECTOR, sd); + + /* ask SAL to close the subchannel */ + rv = ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch); + + kfree(sd); + return rv; +} + +/* + * scdrv_read + * + * Called to read bytes from the open IRouter pipe. + * + */ + +static inline int +read_status_check(struct subch_data_s *sd, int *len) +{ + return ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch, sd->sd_rb, len); +} + +static ssize_t +scdrv_read(struct file *file, char __user *buf, size_t count, loff_t *f_pos) +{ + int status; + int len; + unsigned long flags; + struct subch_data_s *sd = (struct subch_data_s *) file->private_data; + + /* try to get control of the read buffer */ + if (down_trylock(&sd->sd_rbs)) { + /* somebody else has it now; + * if we're non-blocking, then exit... + */ + if (file->f_flags & O_NONBLOCK) { + return -EAGAIN; + } + /* ...or if we want to block, then do so here */ + if (down_interruptible(&sd->sd_rbs)) { + /* something went wrong with wait */ + return -ERESTARTSYS; + } + } + + /* anything to read? */ + len = CHUNKSIZE; + spin_lock_irqsave(&sd->sd_rlock, flags); + status = read_status_check(sd, &len); + + /* if not, and we're blocking I/O, loop */ + while (status < 0) { + DECLARE_WAITQUEUE(wait, current); + + if (file->f_flags & O_NONBLOCK) { + spin_unlock_irqrestore(&sd->sd_rlock, flags); + up(&sd->sd_rbs); + return -EAGAIN; + } + + len = CHUNKSIZE; + set_current_state(TASK_INTERRUPTIBLE); + add_wait_queue(&sd->sd_rq, &wait); + spin_unlock_irqrestore(&sd->sd_rlock, flags); + + schedule_timeout(msecs_to_jiffies(SCDRV_TIMEOUT)); + + remove_wait_queue(&sd->sd_rq, &wait); + if (signal_pending(current)) { + /* wait was interrupted */ + up(&sd->sd_rbs); + return -ERESTARTSYS; + } + + spin_lock_irqsave(&sd->sd_rlock, flags); + status = read_status_check(sd, &len); + } + spin_unlock_irqrestore(&sd->sd_rlock, flags); + + if (len > 0) { + /* we read something in the last read_status_check(); copy + * it out to user space + */ + if (count < len) { + pr_debug("%s: only accepting %d of %d bytes\n", + __func__, (int) count, len); + } + len = min((int) count, len); + if (copy_to_user(buf, sd->sd_rb, len)) + len = -EFAULT; + } + + /* release the read buffer and wake anyone who might be + * waiting for it + */ + up(&sd->sd_rbs); + + /* return the number of characters read in */ + return len; +} + +/* + * scdrv_write + * + * Writes a chunk of an IRouter packet (or other system controller data) + * to the system controller. + * + */ +static inline int +write_status_check(struct subch_data_s *sd, int count) +{ + return ia64_sn_irtr_send(sd->sd_nasid, sd->sd_subch, sd->sd_wb, count); +} + +static ssize_t +scdrv_write(struct file *file, const char __user *buf, + size_t count, loff_t *f_pos) +{ + unsigned long flags; + int status; + struct subch_data_s *sd = (struct subch_data_s *) file->private_data; + + /* try to get control of the write buffer */ + if (down_trylock(&sd->sd_wbs)) { + /* somebody else has it now; + * if we're non-blocking, then exit... + */ + if (file->f_flags & O_NONBLOCK) { + return -EAGAIN; + } + /* ...or if we want to block, then do so here */ + if (down_interruptible(&sd->sd_wbs)) { + /* something went wrong with wait */ + return -ERESTARTSYS; + } + } + + count = min((int) count, CHUNKSIZE); + if (copy_from_user(sd->sd_wb, buf, count)) { + up(&sd->sd_wbs); + return -EFAULT; + } + + /* try to send the buffer */ + spin_lock_irqsave(&sd->sd_wlock, flags); + status = write_status_check(sd, count); + + /* if we failed, and we want to block, then loop */ + while (status <= 0) { + DECLARE_WAITQUEUE(wait, current); + + if (file->f_flags & O_NONBLOCK) { + spin_unlock_irqrestore(&sd->sd_wlock, flags); + up(&sd->sd_wbs); + return -EAGAIN; + } + + set_current_state(TASK_INTERRUPTIBLE); + add_wait_queue(&sd->sd_wq, &wait); + spin_unlock_irqrestore(&sd->sd_wlock, flags); + + schedule_timeout(msecs_to_jiffies(SCDRV_TIMEOUT)); + + remove_wait_queue(&sd->sd_wq, &wait); + if (signal_pending(current)) { + /* wait was interrupted */ + up(&sd->sd_wbs); + return -ERESTARTSYS; + } + + spin_lock_irqsave(&sd->sd_wlock, flags); + status = write_status_check(sd, count); + } + spin_unlock_irqrestore(&sd->sd_wlock, flags); + + /* release the write buffer and wake anyone who's waiting for it */ + up(&sd->sd_wbs); + + /* return the number of characters accepted (should be the complete + * "chunk" as requested) + */ + if ((status >= 0) && (status < count)) { + pr_debug("Didn't accept the full chunk; %d of %d\n", + status, (int) count); + } + return status; +} + +static __poll_t +scdrv_poll(struct file *file, struct poll_table_struct *wait) +{ + __poll_t mask = 0; + int status = 0; + struct subch_data_s *sd = (struct subch_data_s *) file->private_data; + unsigned long flags; + + poll_wait(file, &sd->sd_rq, wait); + poll_wait(file, &sd->sd_wq, wait); + + spin_lock_irqsave(&sd->sd_rlock, flags); + spin_lock(&sd->sd_wlock); + status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch); + spin_unlock(&sd->sd_wlock); + spin_unlock_irqrestore(&sd->sd_rlock, flags); + + if (status > 0) { + if (status & SAL_IROUTER_INTR_RECV) { + mask |= EPOLLIN | EPOLLRDNORM; + } + if (status & SAL_IROUTER_INTR_XMIT) { + mask |= EPOLLOUT | EPOLLWRNORM; + } + } + + return mask; +} + +static const struct file_operations scdrv_fops = { + .owner = THIS_MODULE, + .read = scdrv_read, + .write = scdrv_write, + .poll = scdrv_poll, + .open = scdrv_open, + .release = scdrv_release, + .llseek = noop_llseek, +}; + +static struct class *snsc_class; + +/* + * scdrv_init + * + * Called at boot time to initialize the system controller communication + * facility. + */ +int __init +scdrv_init(void) +{ + geoid_t geoid; + cnodeid_t cnode; + char devname[32]; + char *devnamep; + struct sysctl_data_s *scd; + void *salbuf; + dev_t first_dev, dev; + nasid_t event_nasid; + + if (!ia64_platform_is("sn2")) + return -ENODEV; + + event_nasid = ia64_sn_get_console_nasid(); + + snsc_class = class_create(THIS_MODULE, SYSCTL_BASENAME); + if (IS_ERR(snsc_class)) { + printk("%s: failed to allocate class\n", __func__); + return PTR_ERR(snsc_class); + } + + if (alloc_chrdev_region(&first_dev, 0, num_cnodes, + SYSCTL_BASENAME) < 0) { + printk("%s: failed to register SN system controller device\n", + __func__); + return -ENODEV; + } + + for (cnode = 0; cnode < num_cnodes; cnode++) { + geoid = cnodeid_get_geoid(cnode); + devnamep = devname; + format_module_id(devnamep, geo_module(geoid), + MODULE_FORMAT_BRIEF); + devnamep = devname + strlen(devname); + sprintf(devnamep, "^%d#%d", geo_slot(geoid), + geo_slab(geoid)); + + /* allocate sysctl device data */ + scd = kzalloc(sizeof (struct sysctl_data_s), + GFP_KERNEL); + if (!scd) { + printk("%s: failed to allocate device info" + "for %s/%s\n", __func__, + SYSCTL_BASENAME, devname); + continue; + } + + /* initialize sysctl device data fields */ + scd->scd_nasid = cnodeid_to_nasid(cnode); + if (!(salbuf = kmalloc(SCDRV_BUFSZ, GFP_KERNEL))) { + printk("%s: failed to allocate driver buffer" + "(%s%s)\n", __func__, + SYSCTL_BASENAME, devname); + kfree(scd); + continue; + } + + if (ia64_sn_irtr_init(scd->scd_nasid, salbuf, + SCDRV_BUFSZ) < 0) { + printk + ("%s: failed to initialize SAL for" + " system controller communication" + " (%s/%s): outdated PROM?\n", + __func__, SYSCTL_BASENAME, devname); + kfree(scd); + kfree(salbuf); + continue; + } + + dev = first_dev + cnode; + cdev_init(&scd->scd_cdev, &scdrv_fops); + if (cdev_add(&scd->scd_cdev, dev, 1)) { + printk("%s: failed to register system" + " controller device (%s%s)\n", + __func__, SYSCTL_BASENAME, devname); + kfree(scd); + kfree(salbuf); + continue; + } + + device_create(snsc_class, NULL, dev, NULL, + "%s", devname); + + ia64_sn_irtr_intr_enable(scd->scd_nasid, + 0 /*ignored */ , + SAL_IROUTER_INTR_RECV); + + /* on the console nasid, prepare to receive + * system controller environmental events + */ + if(scd->scd_nasid == event_nasid) { + scdrv_event_init(scd); + } + } + return 0; +} +device_initcall(scdrv_init); |