kernel-ark/drivers/char/snsc.c
akpm@osdl.org 8c4335a87c [PATCH] Altix snsc: duplicate kobject fix
from: Greg Howard <ghoward@sgi.com>

Fix Altix system controller (snsc) device names to include the slot number
of the blade whose associated system controller is the target of the device
interface.  Including the slot number avoids a problem we're currently
having where slots within the same enclosure are attempting to create
multiple kobjects with identical names.

Signed-off-by: Greg Howard <ghoward@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-22 09:19:53 -07:00

457 lines
11 KiB
C

/*
* 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.h>
#include <linux/device.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/slab.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 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 = kzalloc(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 */
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;
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&sd->sd_rq, &wait);
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;
}
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&sd->sd_wq, &wait);
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,
};
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 = ia64_sn_get_console_nasid();
if (alloc_chrdev_region(&first_dev, 0, num_cnodes,
SYSCTL_BASENAME) < 0) {
printk("%s: failed to register SN system controller device\n",
__FUNCTION__);
return -ENODEV;
}
snsc_class = class_create(THIS_MODULE, SYSCTL_BASENAME);
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", __FUNCTION__,
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", __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 + 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",
__FUNCTION__, SYSCTL_BASENAME, devname);
kfree(scd);
kfree(salbuf);
continue;
}
class_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;
}
module_init(scdrv_init);