[PATCH] 2.6.0-test3 - Watchdog patches (alim7101_wdt.c)

From: Wim Van Sebroeck
Date: Sun Aug 10 2003 - 07:57:51 EST


Hi Linus,

please do a

bk pull http://linux-watchdog.bkbits.net/linux-2.5-watchdog

This will update the following files:

drivers/char/watchdog/alim7101_wdt.c | 178 ++++++++++++++++++++++-------------
1 files changed, 115 insertions(+), 63 deletions(-)

through these ChangeSets:

<wim@xxxxxxxxx> (03/08/10 1.1151)
[WATCHDOG] alim7101_wdt.c patch

cleanup comments and trailing spaces
added extra printk's to report what problem occured
added MODULE_DESCRIPTION

<wim@xxxxxxxxx> (03/08/10 1.1152)
[WATCHDOG] alim7101_wdt.c patch2

changed watchdog_info to correctly reflect what the driver offers
added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS and WDIOC_SETOPTIONS ioctls

<wim@xxxxxxxxx> (03/08/10 1.1153)
[WATCHDOG] alim7101_wdt.c patch3

added WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctls
made timeout (the emulated heartbeat) a module_param
made the keepalive ping an internal subroutine


The ChangeSets can also be looked at on:
http://linux-watchdog.bkbits.net:8080/linux-2.5-watchdog

For completeness, I added the patches below.

Greetings,
Wim.

================================================================================
diff -Nru a/drivers/char/watchdog/alim7101_wdt.c b/drivers/char/watchdog/alim7101_wdt.c
--- a/drivers/char/watchdog/alim7101_wdt.c Sun Aug 10 14:43:48 2003
+++ b/drivers/char/watchdog/alim7101_wdt.c Sun Aug 10 14:43:48 2003
@@ -1,26 +1,11 @@
/*
- * ALi M7101 PMU Computer Watchdog Timer driver for Linux 2.4.x
+ * ALi M7101 PMU Computer Watchdog Timer driver
*
- * Based on w83877f_wdt.c by Scott Jennings <management@xxxxxxx>
+ * Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@xxxxxxx>
* and the Cobalt kernel WDT timer driver by Tim Hockin
* <thockin@xxxxxxxxxxxxx>
*
* (c)2002 Steve Hill <steve@xxxxxxxxxxxx>
- *
- * Theory of operation:
- * A Watchdog Timer (WDT) is a hardware circuit that can
- * reset the computer system in case of a software fault.
- * You probably knew that already.
- *
- * Usually a userspace daemon will notify the kernel WDT driver
- * via the /proc/watchdog special device file that userspace is
- * still alive, at regular intervals. When such a notification
- * occurs, the driver will usually tell the hardware watchdog
- * that everything is in order, and that the watchdog should wait
- * for yet another little while to reset the system.
- * If userspace fails (RAM error, kernel bug, whatever), the
- * notifications cease to occur, and the hardware watchdog will
- * reset the system (causing a reboot) after the timeout occurs.
*
* This WDT driver is different from most other Linux WDT
* drivers in that the driver will ping the watchdog by itself,
@@ -30,6 +15,7 @@
*/

#include <linux/module.h>
+#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/miscdevice.h>
@@ -38,7 +24,6 @@
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
-#include <linux/moduleparam.h>
#include <linux/pci.h>

#include <asm/io.h>
@@ -46,6 +31,7 @@
#include <asm/system.h>

#define OUR_NAME "alim7101_wdt"
+#define PFX OUR_NAME ": "

#define WDT_ENABLE 0x9C
#define WDT_DISABLE 0x8C
@@ -79,7 +65,7 @@
#else
static int nowayout = 0;
#endif
-
+
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

@@ -90,25 +76,25 @@
static void wdt_timer_ping(unsigned long data)
{
/* If we got a heartbeat pulse within the WDT_US_INTERVAL
- * we agree to ping the WDT
+ * we agree to ping the WDT
*/
char tmp;

- if(time_before(jiffies, next_heartbeat))
+ 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));
} else {
- printk(KERN_INFO OUR_NAME ": Heartbeat lost! Will not ping the watchdog\n");
+ printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
}
/* Re-set the timer interval */
timer.expires = jiffies + WDT_INTERVAL;
add_timer(&timer);
}

-/*
+/*
* Utility routines
*/

@@ -133,11 +119,11 @@
wdt_change(WDT_ENABLE);

/* Start the timer */
- timer.expires = jiffies + WDT_INTERVAL;
+ timer.expires = jiffies + WDT_INTERVAL;
add_timer(&timer);


- printk(KERN_INFO OUR_NAME ": Watchdog timer is now enabled.\n");
+ printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
}

static void wdt_turnoff(void)
@@ -145,7 +131,7 @@
/* Stop the timer */
del_timer_sync(&timer);
wdt_change(WDT_DISABLE);
- printk(KERN_INFO OUR_NAME ": Watchdog timer is now disabled...\n");
+ printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
}

/*
@@ -173,14 +159,13 @@
if (get_user(c, buf+ofs))
return -EFAULT;
if (c == 'V')
- wdt_expect_close = 1;
+ wdt_expect_close = 42;
}
}
/* someone wrote to us, we should restart timer */
next_heartbeat = jiffies + WDT_HEARTBEAT;
- return 1;
- };
- return 0;
+ }
+ return count;
}

static int fop_open(struct inode * inode, struct file * file)
@@ -195,12 +180,13 @@

static int fop_close(struct inode * inode, struct file * file)
{
- if(wdt_expect_close)
+ if(wdt_expect_close == 42)
wdt_turnoff();
- else
- printk(KERN_INFO OUR_NAME ": device file closed unexpectedly. Will not stop the WDT!\n");
-
+ else {
+ printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n");
+ }
clear_bit(0, &wdt_is_open);
+ wdt_expect_close = 0;
return 0;
}

@@ -210,9 +196,9 @@
{
.options = WDIOF_MAGICCLOSE,
.firmware_version = 1,
- .identity = "ALiM7101"
+ .identity = "ALiM7101",
};
-
+
switch(cmd)
{
case WDIOC_GETSUPPORT:
@@ -231,13 +217,13 @@
.write= fop_write,
.open= fop_open,
.release= fop_close,
- .ioctl= fop_ioctl
+ .ioctl= fop_ioctl,
};

static struct miscdevice wdt_miscdev = {
.minor=WATCHDOG_MINOR,
.name="watchdog",
- .fops=&wdt_fops
+ .fops=&wdt_fops,
};

/*
@@ -256,21 +242,21 @@
* reboot with no heartbeat
*/
wdt_change(WDT_ENABLE);
- printk(KERN_INFO OUR_NAME ": Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second.\n");
+ printk(KERN_INFO PFX "Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second.\n");
}
return NOTIFY_DONE;
}
-
+
/*
* The WDT needs to learn about soft shutdowns in order to
- * turn the timebomb registers off.
+ * turn the timebomb registers off.
*/
-
+
static struct notifier_block wdt_notifier=
{
.notifier_call = wdt_notify_sys,
.next = 0,
- .priority = 0
+ .priority = 0,
};

static void __exit alim7101_wdt_unload(void)
@@ -287,10 +273,10 @@
struct pci_dev *ali1543_south;
char tmp;

- printk(KERN_INFO OUR_NAME ": Steve Hill <steve@xxxxxxxxxxxx>.\n");
+ printk(KERN_INFO PFX "Steve Hill <steve@xxxxxxxxxxxx>.\n");
alim7101_pmu = pci_find_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,NULL);
if (!alim7101_pmu) {
- printk(KERN_INFO OUR_NAME ": ALi M7101 PMU not present - WDT not set\n");
+ printk(KERN_INFO PFX "ALi M7101 PMU not present - WDT not set\n");
return -EBUSY;
}

@@ -299,12 +285,12 @@

ali1543_south = pci_find_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL);
if (!ali1543_south) {
- printk(KERN_INFO OUR_NAME ": ALi 1543 South-Bridge not present - WDT not set\n");
+ printk(KERN_INFO PFX "ALi 1543 South-Bridge not present - WDT not set\n");
return -EBUSY;
}
pci_read_config_byte(ali1543_south, 0x5e, &tmp);
if ((tmp & 0x1e) != 0x12) {
- printk(KERN_INFO OUR_NAME ": ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
+ printk(KERN_INFO PFX "ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
return -EBUSY;
}

@@ -313,21 +299,32 @@
timer.data = 1;

rc = misc_register(&wdt_miscdev);
- if (rc)
- return rc;
+ if (rc) {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ wdt_miscdev.minor, rc);
+ goto err_out;
+ }

rc = register_reboot_notifier(&wdt_notifier);
if (rc) {
- misc_deregister(&wdt_miscdev);
- return rc;
+ printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+ rc);
+ goto err_out_miscdev;
}

- printk(KERN_INFO OUR_NAME ": WDT driver for ALi M7101 initialised.\n");
+ printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. (nowayout=%d)\n",
+ nowayout);
return 0;
+
+err_out_miscdev:
+ misc_deregister(&wdt_miscdev);
+err_out:
+ return rc;
}

module_init(alim7101_wdt_init);
module_exit(alim7101_wdt_unload);

MODULE_AUTHOR("Steve Hill");
+MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
MODULE_LICENSE("GPL");
diff -Nru a/drivers/char/watchdog/alim7101_wdt.c b/drivers/char/watchdog/alim7101_wdt.c
--- a/drivers/char/watchdog/alim7101_wdt.c Sun Aug 10 14:44:07 2003
+++ b/drivers/char/watchdog/alim7101_wdt.c Sun Aug 10 14:44:07 2003
@@ -57,7 +57,7 @@
static struct timer_list timer;
static unsigned long next_heartbeat;
static unsigned long wdt_is_open;
-static int wdt_expect_close;
+static char wdt_expect_close;
static struct pci_dev *alim7101_pmu;

#ifdef CONFIG_WATCHDOG_NOWAYOUT
@@ -144,7 +144,7 @@
if(ppos != &file->f_pos)
return -ESPIPE;

- /* See if we got the magic character */
+ /* See if we got the magic character 'V' and reload the timer */
if(count) {
if (!nowayout) {
size_t ofs;
@@ -183,6 +183,7 @@
if(wdt_expect_close == 42)
wdt_turnoff();
else {
+ /* wim: shouldn't there be a: del_timer(&timer); */
printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n");
}
clear_bit(0, &wdt_is_open);
@@ -194,7 +195,7 @@
{
static struct watchdog_info ident =
{
- .options = WDIOF_MAGICCLOSE,
+ .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "ALiM7101",
};
@@ -203,11 +204,33 @@
{
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))?-EFAULT:0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
next_heartbeat = jiffies + WDT_HEARTBEAT;
return 0;
+ case WDIOC_SETOPTIONS:
+ {
+ int new_options, retval = -EINVAL;
+
+ if(get_user(new_options, (int *)arg))
+ return -EFAULT;
+
+ if(new_options & WDIOS_DISABLECARD) {
+ wdt_turnoff();
+ retval = 0;
+ }
+
+ if(new_options & WDIOS_ENABLECARD) {
+ wdt_startup();
+ retval = 0;
+ }
+
+ return retval;
+ }
default:
- return -ENOTTY;
+ return -ENOIOCTLCMD;
}
}

diff -Nru a/drivers/char/watchdog/alim7101_wdt.c b/drivers/char/watchdog/alim7101_wdt.c
--- a/drivers/char/watchdog/alim7101_wdt.c Sun Aug 10 14:44:27 2003
+++ b/drivers/char/watchdog/alim7101_wdt.c Sun Aug 10 14:44:27 2003
@@ -51,7 +51,10 @@
* char to /dev/watchdog every 30 seconds.
*/

-#define WDT_HEARTBEAT (HZ * 30)
+#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
+static int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");

static void wdt_timer_ping(unsigned long);
static struct timer_list timer;
@@ -111,7 +114,7 @@

static void wdt_startup(void)
{
- next_heartbeat = jiffies + WDT_HEARTBEAT;
+ next_heartbeat = jiffies + (timeout * HZ);

/* We must enable before we kick off the timer in case the timer
occurs as we ping it */
@@ -134,6 +137,12 @@
printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
}

+static void wdt_keepalive(void)
+{
+ /* user land ping */
+ next_heartbeat = jiffies + (timeout * HZ);
+}
+
/*
* /dev/watchdog handling
*/
@@ -163,7 +172,7 @@
}
}
/* someone wrote to us, we should restart timer */
- next_heartbeat = jiffies + WDT_HEARTBEAT;
+ wdt_keepalive();
}
return count;
}
@@ -195,7 +204,7 @@
{
static struct watchdog_info ident =
{
- .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "ALiM7101",
};
@@ -208,7 +217,7 @@
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
- next_heartbeat = jiffies + WDT_HEARTBEAT;
+ wdt_keepalive();
return 0;
case WDIOC_SETOPTIONS:
{
@@ -229,6 +238,22 @@

return retval;
}
+ case WDIOC_SETTIMEOUT:
+ {
+ int new_timeout;
+
+ if(get_user(new_timeout, (int *)arg))
+ return -EFAULT;
+
+ if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */
+ return -EINVAL;
+
+ timeout = new_timeout;
+ wdt_keepalive();
+ /* Fall through */
+ }
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, (int *)arg);
default:
return -ENOIOCTLCMD;
}
@@ -317,6 +342,13 @@
return -EBUSY;
}

+ if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */
+ {
+ timeout = WATCHDOG_TIMEOUT;
+ printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n",
+ timeout);
+ }
+
init_timer(&timer);
timer.function = wdt_timer_ping;
timer.data = 1;
@@ -335,8 +367,8 @@
goto err_out_miscdev;
}

- printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. (nowayout=%d)\n",
- nowayout);
+ printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
+ timeout, nowayout);
return 0;

err_out_miscdev:
-
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