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linux/drivers/char/watchdog/ibmasr.c
Arjan van de Ven 62322d2554 [PATCH] make more file_operation structs static 
Mark the static struct file_operations in drivers/char as const.  Making
them const prevents accidental bugs, and moves them to the .rodata section
so that they no longer do any false sharing; in addition with the proper
debug option they are then protected against corruption..

[akpm@osdl.org: build fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:26:59 -07:00

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9.0 KiB
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/*
* IBM Automatic Server Restart driver.
*
* Copyright (c) 2005 Andrey Panin <pazke@donpac.ru>
*
* Based on driver written by Pete Reynolds.
* Copyright (c) IBM Corporation, 1998-2004.
*
* This software may be used and distributed according to the terms
* of the GNU Public License, incorporated herein by reference.
*/
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/timer.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/dmi.h>
#include <asm/io.h>
#include <asm/uaccess.h>
enum {
ASMTYPE_UNKNOWN,
ASMTYPE_TOPAZ,
ASMTYPE_JASPER,
ASMTYPE_PEARL,
ASMTYPE_JUNIPER,
ASMTYPE_SPRUCE,
};
#define PFX "ibmasr: "
#define TOPAZ_ASR_REG_OFFSET 4
#define TOPAZ_ASR_TOGGLE 0x40
#define TOPAZ_ASR_DISABLE 0x80
/* PEARL ASR S/W REGISTER SUPERIO PORT ADDRESSES */
#define PEARL_BASE 0xe04
#define PEARL_WRITE 0xe06
#define PEARL_READ 0xe07
#define PEARL_ASR_DISABLE_MASK 0x80 /* bit 7: disable = 1, enable = 0 */
#define PEARL_ASR_TOGGLE_MASK 0x40 /* bit 6: 0, then 1, then 0 */
/* JASPER OFFSET FROM SIO BASE ADDR TO ASR S/W REGISTERS. */
#define JASPER_ASR_REG_OFFSET 0x38
#define JASPER_ASR_DISABLE_MASK 0x01 /* bit 0: disable = 1, enable = 0 */
#define JASPER_ASR_TOGGLE_MASK 0x02 /* bit 1: 0, then 1, then 0 */
#define JUNIPER_BASE_ADDRESS 0x54b /* Base address of Juniper ASR */
#define JUNIPER_ASR_DISABLE_MASK 0x01 /* bit 0: disable = 1 enable = 0 */
#define JUNIPER_ASR_TOGGLE_MASK 0x02 /* bit 1: 0, then 1, then 0 */
#define SPRUCE_BASE_ADDRESS 0x118e /* Base address of Spruce ASR */
#define SPRUCE_ASR_DISABLE_MASK 0x01 /* bit 1: disable = 1 enable = 0 */
#define SPRUCE_ASR_TOGGLE_MASK 0x02 /* bit 0: 0, then 1, then 0 */
static int nowayout = WATCHDOG_NOWAYOUT;
static unsigned long asr_is_open;
static char asr_expect_close;
static unsigned int asr_type, asr_base, asr_length;
static unsigned int asr_read_addr, asr_write_addr;
static unsigned char asr_toggle_mask, asr_disable_mask;
static void asr_toggle(void)
{
unsigned char reg = inb(asr_read_addr);
outb(reg & ~asr_toggle_mask, asr_write_addr);
reg = inb(asr_read_addr);
outb(reg | asr_toggle_mask, asr_write_addr);
reg = inb(asr_read_addr);
outb(reg & ~asr_toggle_mask, asr_write_addr);
reg = inb(asr_read_addr);
}
static void asr_enable(void)
{
unsigned char reg;
if (asr_type == ASMTYPE_TOPAZ) {
/* asr_write_addr == asr_read_addr */
reg = inb(asr_read_addr);
outb(reg & ~(TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE),
asr_read_addr);
} else {
/*
* First make sure the hardware timer is reset by toggling
* ASR hardware timer line.
*/
asr_toggle();
reg = inb(asr_read_addr);
outb(reg & ~asr_disable_mask, asr_write_addr);
}
reg = inb(asr_read_addr);
}
static void asr_disable(void)
{
unsigned char reg = inb(asr_read_addr);
if (asr_type == ASMTYPE_TOPAZ)
/* asr_write_addr == asr_read_addr */
outb(reg | TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE,
asr_read_addr);
else {
outb(reg | asr_toggle_mask, asr_write_addr);
reg = inb(asr_read_addr);
outb(reg | asr_disable_mask, asr_write_addr);
}
reg = inb(asr_read_addr);
}
static int __init asr_get_base_address(void)
{
unsigned char low, high;
const char *type = "";
asr_length = 1;
switch (asr_type) {
case ASMTYPE_TOPAZ:
/* SELECT SuperIO CHIP FOR QUERYING (WRITE 0x07 TO BOTH 0x2E and 0x2F) */
outb(0x07, 0x2e);
outb(0x07, 0x2f);
/* SELECT AND READ THE HIGH-NIBBLE OF THE GPIO BASE ADDRESS */
outb(0x60, 0x2e);
high = inb(0x2f);
/* SELECT AND READ THE LOW-NIBBLE OF THE GPIO BASE ADDRESS */
outb(0x61, 0x2e);
low = inb(0x2f);
asr_base = (high << 16) | low;
asr_read_addr = asr_write_addr =
asr_base + TOPAZ_ASR_REG_OFFSET;
asr_length = 5;
break;
case ASMTYPE_JASPER:
type = "Jaspers ";
/* FIXME: need to use pci_config_lock here, but it's not exported */
/* spin_lock_irqsave(&pci_config_lock, flags);*/
/* Select the SuperIO chip in the PCI I/O port register */
outl(0x8000f858, 0xcf8);
/*
* Read the base address for the SuperIO chip.
* Only the lower 16 bits are valid, but the address is word
* aligned so the last bit must be masked off.
*/
asr_base = inl(0xcfc) & 0xfffe;
/* spin_unlock_irqrestore(&pci_config_lock, flags);*/
asr_read_addr = asr_write_addr =
asr_base + JASPER_ASR_REG_OFFSET;
asr_toggle_mask = JASPER_ASR_TOGGLE_MASK;
asr_disable_mask = JASPER_ASR_DISABLE_MASK;
asr_length = JASPER_ASR_REG_OFFSET + 1;
break;
case ASMTYPE_PEARL:
type = "Pearls ";
asr_base = PEARL_BASE;
asr_read_addr = PEARL_READ;
asr_write_addr = PEARL_WRITE;
asr_toggle_mask = PEARL_ASR_TOGGLE_MASK;
asr_disable_mask = PEARL_ASR_DISABLE_MASK;
asr_length = 4;
break;
case ASMTYPE_JUNIPER:
type = "Junipers ";
asr_base = JUNIPER_BASE_ADDRESS;
asr_read_addr = asr_write_addr = asr_base;
asr_toggle_mask = JUNIPER_ASR_TOGGLE_MASK;
asr_disable_mask = JUNIPER_ASR_DISABLE_MASK;
break;
case ASMTYPE_SPRUCE:
type = "Spruce's ";
asr_base = SPRUCE_BASE_ADDRESS;
asr_read_addr = asr_write_addr = asr_base;
asr_toggle_mask = SPRUCE_ASR_TOGGLE_MASK;
asr_disable_mask = SPRUCE_ASR_DISABLE_MASK;
break;
}
if (!request_region(asr_base, asr_length, "ibmasr")) {
printk(KERN_ERR PFX "address %#x already in use\n",
asr_base);
return -EBUSY;
}
printk(KERN_INFO PFX "found %sASR @ addr %#x\n", type, asr_base);
return 0;
}
static ssize_t asr_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
asr_expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
asr_expect_close = 42;
}
}
asr_toggle();
}
return count;
}
static int asr_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.identity = "IBM ASR"
};
void __user *argp = (void __user *)arg;
int __user *p = argp;
int heartbeat;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &ident, sizeof(ident)) ?
-EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
asr_toggle();
return 0;
/*
* The hardware has a fixed timeout value, so no WDIOC_SETTIMEOUT
* and WDIOC_GETTIMEOUT always returns 256.
*/
case WDIOC_GETTIMEOUT:
heartbeat = 256;
return put_user(heartbeat, p);
case WDIOC_SETOPTIONS: {
int new_options, retval = -EINVAL;
if (get_user(new_options, p))
return -EFAULT;
if (new_options & WDIOS_DISABLECARD) {
asr_disable();
retval = 0;
}
if (new_options & WDIOS_ENABLECARD) {
asr_enable();
asr_toggle();
retval = 0;
}
return retval;
}
}
return -ENOIOCTLCMD;
}
static int asr_open(struct inode *inode, struct file *file)
{
if(test_and_set_bit(0, &asr_is_open))
return -EBUSY;
asr_toggle();
asr_enable();
return nonseekable_open(inode, file);
}
static int asr_release(struct inode *inode, struct file *file)
{
if (asr_expect_close == 42)
asr_disable();
else {
printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
asr_toggle();
}
clear_bit(0, &asr_is_open);
asr_expect_close = 0;
return 0;
}
static const struct file_operations asr_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = asr_write,
.ioctl = asr_ioctl,
.open = asr_open,
.release = asr_release,
};
static struct miscdevice asr_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &asr_fops,
};
struct ibmasr_id {
const char *desc;
int type;
};
static struct ibmasr_id __initdata ibmasr_id_table[] = {
{ "IBM Automatic Server Restart - eserver xSeries 220", ASMTYPE_TOPAZ },
{ "IBM Automatic Server Restart - Machine Type 8673", ASMTYPE_PEARL },
{ "IBM Automatic Server Restart - Machine Type 8480", ASMTYPE_JASPER },
{ "IBM Automatic Server Restart - Machine Type 8482", ASMTYPE_JUNIPER },
{ "IBM Automatic Server Restart - Machine Type 8648", ASMTYPE_SPRUCE },
{ NULL }
};
static int __init ibmasr_init(void)
{
struct ibmasr_id *id;
int rc;
for (id = ibmasr_id_table; id->desc; id++) {
if (dmi_find_device(DMI_DEV_TYPE_OTHER, id->desc, NULL)) {
asr_type = id->type;
break;
}
}
if (!asr_type)
return -ENODEV;
rc = misc_register(&asr_miscdev);
if (rc < 0) {
printk(KERN_ERR PFX "failed to register misc device\n");
return rc;
}
rc = asr_get_base_address();
if (rc) {
misc_deregister(&asr_miscdev);
return rc;
}
return 0;
}
static void __exit ibmasr_exit(void)
{
if (!nowayout)
asr_disable();
misc_deregister(&asr_miscdev);
release_region(asr_base, asr_length);
}
module_init(ibmasr_init);
module_exit(ibmasr_exit);
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
MODULE_DESCRIPTION("IBM Automatic Server Restart driver");
MODULE_AUTHOR("Andrey Panin");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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