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linux-next/drivers/watchdog/alim7101_wdt.c
Kees Cook 24ed960abf treewide: Switch DEFINE_TIMER callbacks to struct timer_list *
This changes all DEFINE_TIMER() callbacks to use a struct timer_list
pointer instead of unsigned long. Since the data argument has already been
removed, none of these callbacks are using their argument currently, so
this renames the argument to "unused".

Done using the following semantic patch:

@match_define_timer@
declarer name DEFINE_TIMER;
identifier _timer, _callback;
@@

 DEFINE_TIMER(_timer, _callback);

@change_callback depends on match_define_timer@
identifier match_define_timer._callback;
type _origtype;
identifier _origarg;
@@

 void
-_callback(_origtype _origarg)
+_callback(struct timer_list *unused)
 { ... }

Signed-off-by: Kees Cook <keescook@chromium.org>
2017-11-21 15:57:05 -08:00

450 lines
11 KiB
C

/*
* ALi M7101 PMU Computer Watchdog Timer driver
*
* Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net>
* and the Cobalt kernel WDT timer driver by Tim Hockin
* <thockin@cobaltnet.com>
*
* (c)2002 Steve Hill <steve@navaho.co.uk>
*
* This WDT driver is different from most other Linux WDT
* drivers in that the driver will ping the watchdog by itself,
* because this particular WDT has a very short timeout (1.6
* seconds) and it would be insane to count on any userspace
* daemon always getting scheduled within that time frame.
*
* Additions:
* Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs
* found on very old cobalt hardware.
* -- Mike Waychison <michael.waychison@sun.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#define WDT_ENABLE 0x9C
#define WDT_DISABLE 0x8C
#define ALI_7101_WDT 0x92
#define ALI_7101_GPIO 0x7D
#define ALI_7101_GPIO_O 0x7E
#define ALI_WDT_ARM 0x01
/*
* We're going to use a 1 second timeout.
* If we reset the watchdog every ~250ms we should be safe. */
#define WDT_INTERVAL (HZ/4+1)
/*
* We must not require too good response from the userspace daemon.
* Here we require the userspace daemon to send us a heartbeat
* char to /dev/watchdog every 30 seconds.
*/
#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
static int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. (1<=timeout<=3600, default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
static int use_gpio; /* Use the pic (for a1d revision alim7101) */
module_param(use_gpio, int, 0);
MODULE_PARM_DESC(use_gpio,
"Use the gpio watchdog (required by old cobalt boards).");
static void wdt_timer_ping(struct timer_list *);
static DEFINE_TIMER(timer, wdt_timer_ping);
static unsigned long next_heartbeat;
static unsigned long wdt_is_open;
static char wdt_expect_close;
static struct pci_dev *alim7101_pmu;
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/*
* Whack the dog
*/
static void wdt_timer_ping(struct timer_list *unused)
{
/* If we got a heartbeat pulse within the WDT_US_INTERVAL
* we agree to ping the WDT
*/
char tmp;
if (time_before(jiffies, next_heartbeat)) {
/* Ping the WDT (this is actually a disarm/arm sequence) */
pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
pci_write_config_byte(alim7101_pmu,
ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
pci_write_config_byte(alim7101_pmu,
ALI_7101_WDT, (tmp | ALI_WDT_ARM));
if (use_gpio) {
pci_read_config_byte(alim7101_pmu,
ALI_7101_GPIO_O, &tmp);
pci_write_config_byte(alim7101_pmu,
ALI_7101_GPIO_O, tmp | 0x20);
pci_write_config_byte(alim7101_pmu,
ALI_7101_GPIO_O, tmp & ~0x20);
}
} else {
pr_warn("Heartbeat lost! Will not ping the watchdog\n");
}
/* Re-set the timer interval */
mod_timer(&timer, jiffies + WDT_INTERVAL);
}
/*
* Utility routines
*/
static void wdt_change(int writeval)
{
char tmp;
pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
if (writeval == WDT_ENABLE) {
pci_write_config_byte(alim7101_pmu,
ALI_7101_WDT, (tmp | ALI_WDT_ARM));
if (use_gpio) {
pci_read_config_byte(alim7101_pmu,
ALI_7101_GPIO_O, &tmp);
pci_write_config_byte(alim7101_pmu,
ALI_7101_GPIO_O, tmp & ~0x20);
}
} else {
pci_write_config_byte(alim7101_pmu,
ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
if (use_gpio) {
pci_read_config_byte(alim7101_pmu,
ALI_7101_GPIO_O, &tmp);
pci_write_config_byte(alim7101_pmu,
ALI_7101_GPIO_O, tmp | 0x20);
}
}
}
static void wdt_startup(void)
{
next_heartbeat = jiffies + (timeout * HZ);
/* We must enable before we kick off the timer in case the timer
occurs as we ping it */
wdt_change(WDT_ENABLE);
/* Start the timer */
mod_timer(&timer, jiffies + WDT_INTERVAL);
pr_info("Watchdog timer is now enabled\n");
}
static void wdt_turnoff(void)
{
/* Stop the timer */
del_timer_sync(&timer);
wdt_change(WDT_DISABLE);
pr_info("Watchdog timer is now disabled...\n");
}
static void wdt_keepalive(void)
{
/* user land ping */
next_heartbeat = jiffies + (timeout * HZ);
}
/*
* /dev/watchdog handling
*/
static ssize_t fop_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
/* See if we got the magic character 'V' and reload the timer */
if (count) {
if (!nowayout) {
size_t ofs;
/* note: just in case someone wrote the magic character
* five months ago... */
wdt_expect_close = 0;
/* now scan */
for (ofs = 0; ofs != count; ofs++) {
char c;
if (get_user(c, buf + ofs))
return -EFAULT;
if (c == 'V')
wdt_expect_close = 42;
}
}
/* someone wrote to us, we should restart timer */
wdt_keepalive();
}
return count;
}
static int fop_open(struct inode *inode, struct file *file)
{
/* Just in case we're already talking to someone... */
if (test_and_set_bit(0, &wdt_is_open))
return -EBUSY;
/* Good, fire up the show */
wdt_startup();
return nonseekable_open(inode, file);
}
static int fop_close(struct inode *inode, struct file *file)
{
if (wdt_expect_close == 42)
wdt_turnoff();
else {
/* wim: shouldn't there be a: del_timer(&timer); */
pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
}
clear_bit(0, &wdt_is_open);
wdt_expect_close = 0;
return 0;
}
static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
| WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "ALiM7101",
};
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_SETOPTIONS:
{
int new_options, retval = -EINVAL;
if (get_user(new_options, p))
return -EFAULT;
if (new_options & WDIOS_DISABLECARD) {
wdt_turnoff();
retval = 0;
}
if (new_options & WDIOS_ENABLECARD) {
wdt_startup();
retval = 0;
}
return retval;
}
case WDIOC_KEEPALIVE:
wdt_keepalive();
return 0;
case WDIOC_SETTIMEOUT:
{
int new_timeout;
if (get_user(new_timeout, p))
return -EFAULT;
/* arbitrary upper limit */
if (new_timeout < 1 || new_timeout > 3600)
return -EINVAL;
timeout = new_timeout;
wdt_keepalive();
/* Fall through */
}
case WDIOC_GETTIMEOUT:
return put_user(timeout, p);
default:
return -ENOTTY;
}
}
static const struct file_operations wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = fop_write,
.open = fop_open,
.release = fop_close,
.unlocked_ioctl = fop_ioctl,
};
static struct miscdevice wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdt_fops,
};
static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
void *cmd)
{
/*
* Cobalt devices have no way of rebooting themselves other
* than getting the watchdog to pull reset, so we restart the
* watchdog on reboot with no heartbeat.
*/
wdt_change(WDT_ENABLE);
/* loop until the watchdog fires */
while (true)
;
return NOTIFY_DONE;
}
static struct notifier_block wdt_restart_handler = {
.notifier_call = wdt_restart_handle,
.priority = 128,
};
/*
* Notifier for system down
*/
static int wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
wdt_turnoff();
return NOTIFY_DONE;
}
/*
* The WDT needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block wdt_notifier = {
.notifier_call = wdt_notify_sys,
};
static void __exit alim7101_wdt_unload(void)
{
wdt_turnoff();
/* Deregister */
misc_deregister(&wdt_miscdev);
unregister_reboot_notifier(&wdt_notifier);
unregister_restart_handler(&wdt_restart_handler);
pci_dev_put(alim7101_pmu);
}
static int __init alim7101_wdt_init(void)
{
int rc = -EBUSY;
struct pci_dev *ali1543_south;
char tmp;
pr_info("Steve Hill <steve@navaho.co.uk>\n");
alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
NULL);
if (!alim7101_pmu) {
pr_info("ALi M7101 PMU not present - WDT not set\n");
return -EBUSY;
}
/* Set the WDT in the PMU to 1 second */
pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
NULL);
if (!ali1543_south) {
pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
goto err_out;
}
pci_read_config_byte(ali1543_south, 0x5e, &tmp);
pci_dev_put(ali1543_south);
if ((tmp & 0x1e) == 0x00) {
if (!use_gpio) {
pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
goto err_out;
}
nowayout = 1;
} else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
goto err_out;
}
if (timeout < 1 || timeout > 3600) {
/* arbitrary upper limit */
timeout = WATCHDOG_TIMEOUT;
pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
timeout);
}
rc = register_reboot_notifier(&wdt_notifier);
if (rc) {
pr_err("cannot register reboot notifier (err=%d)\n", rc);
goto err_out;
}
rc = register_restart_handler(&wdt_restart_handler);
if (rc) {
pr_err("cannot register restart handler (err=%d)\n", rc);
goto err_out_reboot;
}
rc = misc_register(&wdt_miscdev);
if (rc) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
wdt_miscdev.minor, rc);
goto err_out_restart;
}
if (nowayout)
__module_get(THIS_MODULE);
pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
timeout, nowayout);
return 0;
err_out_restart:
unregister_restart_handler(&wdt_restart_handler);
err_out_reboot:
unregister_reboot_notifier(&wdt_notifier);
err_out:
pci_dev_put(alim7101_pmu);
return rc;
}
module_init(alim7101_wdt_init);
module_exit(alim7101_wdt_unload);
static const struct pci_device_id alim7101_pci_tbl[] __used = {
{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
{ }
};
MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
MODULE_AUTHOR("Steve Hill");
MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
MODULE_LICENSE("GPL");