--- /dev/null
+/*
+ * 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 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.h>
+#include <linux/device.h>
+#include <linux/poll.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/nodepda.h>
+#include "snsc.h"
+
+#define SYSCTL_BASENAME "snsc"
+
+#define SCDRV_BUFSZ 2048
+#define SCDRV_TIMEOUT 1000
+
+static irqreturn_t
+scdrv_interrupt(int irq, void *subch_data, struct pt_regs *regs)
+{
+ 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 = kmalloc(sizeof (struct subch_data_s), GFP_KERNEL);
+ if (sd == NULL) {
+ printk("%s: couldn't allocate subchannel data\n",
+ __FUNCTION__);
+ return -ENOMEM;
+ }
+
+ /* initialize subch_data_s fields */
+ memset(sd, 0, sizeof (struct subch_data_s));
+ 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", __FUNCTION__);
+ 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 */
+ rv = request_irq(SGI_UART_VECTOR, scdrv_interrupt,
+ SA_SHIRQ | SA_INTERRUPT,
+ SYSCTL_BASENAME, sd);
+ if (rv) {
+ ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch);
+ kfree(sd);
+ printk("%s: irq request failed (%d)\n", __FUNCTION__, rv);
+ return -EBUSY;
+ }
+
+ 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;
+ add_wait_queue(&sd->sd_rq, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+ spin_unlock_irqrestore(&sd->sd_rlock, flags);
+
+ schedule_timeout(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",
+ __FUNCTION__, (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(&sd->sd_wlock);
+ up(&sd->sd_wbs);
+ return -EAGAIN;
+ }
+
+ add_wait_queue(&sd->sd_wq, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+ spin_unlock_irqrestore(&sd->sd_wlock, flags);
+
+ schedule_timeout(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 unsigned int
+scdrv_poll(struct file *file, struct poll_table_struct *wait)
+{
+ unsigned int 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 |= POLLIN | POLLRDNORM;
+ }
+ if (status & SAL_IROUTER_INTR_XMIT) {
+ mask |= POLLOUT | POLLWRNORM;
+ }
+ }
+
+ return mask;
+}
+
+static struct file_operations scdrv_fops = {
+ .owner = THIS_MODULE,
+ .read = scdrv_read,
+ .write = scdrv_write,
+ .poll = scdrv_poll,
+ .open = scdrv_open,
+ .release = scdrv_release,
+};
+
+/*
+ * scdrv_init
+ *
+ * Called at boot time to initialize the system controller communication
+ * facility.
+ */
+int __init
+scdrv_init(void)
+{
+ geoid_t geoid;
+ cmoduleid_t cmod;
+ int i;
+ char devname[32];
+ char *devnamep;
+ module_t *m;
+ struct sysctl_data_s *scd;
+ void *salbuf;
+ struct class_simple *snsc_class;
+ dev_t first_dev, dev;
+
+ if (alloc_chrdev_region(&first_dev, 0, (MAX_SLABS*nummodules),
+ SYSCTL_BASENAME) < 0) {
+ printk("%s: failed to register SN system controller device\n",
+ __FUNCTION__);
+ return -ENODEV;
+ }
+ snsc_class = class_simple_create(THIS_MODULE, SYSCTL_BASENAME);
+
+ for (cmod = 0; cmod < nummodules; cmod++) {
+ m = sn_modules[cmod];
+ for (i = 0; i <= MAX_SLABS; i++) {
+
+ if (m->nodes[i] == -1) {
+ /* node is not alive in module */
+ continue;
+ }
+
+ geoid = m->geoid[i];
+ devnamep = devname;
+ format_module_id(devnamep, geo_module(geoid),
+ MODULE_FORMAT_BRIEF);
+ devnamep = devname + strlen(devname);
+ sprintf(devnamep, "#%d", geo_slab(geoid));
+
+ /* allocate sysctl device data */
+ scd = kmalloc(sizeof (struct sysctl_data_s),
+ GFP_KERNEL);
+ if (!scd) {
+ printk("%s: failed to allocate device info"
+ "for %s/%s\n", __FUNCTION__,
+ SYSCTL_BASENAME, devname);
+ continue;
+ }
+ memset(scd, 0, sizeof (struct sysctl_data_s));
+
+ /* initialize sysctl device data fields */
+ scd->scd_nasid = cnodeid_to_nasid(m->nodes[i]);
+ if (!(salbuf = kmalloc(SCDRV_BUFSZ, GFP_KERNEL))) {
+ printk("%s: failed to allocate driver buffer"
+ "(%s%s)\n", __FUNCTION__,
+ 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",
+ __FUNCTION__, SYSCTL_BASENAME, devname);
+ kfree(scd);
+ kfree(salbuf);
+ continue;
+ }
+
+ dev = first_dev + m->nodes[i];
+ 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",
+ __FUNCTION__, SYSCTL_BASENAME, devname);
+ kfree(scd);
+ kfree(salbuf);
+ continue;
+ }
+
+ class_simple_device_add(snsc_class, dev, NULL,
+ "%s", devname);
+
+ ia64_sn_irtr_intr_enable(scd->scd_nasid,
+ 0 /*ignored */ ,
+ SAL_IROUTER_INTR_RECV);
+ }
+ }
+ return 0;
+}
+
+module_init(scdrv_init);
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