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Subject[PATCH] 2.6.0-test3 - Watchdog patches (sc520_wdt.c)
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/sc520_wdt.c | 248 +++++++++++++++++++++++---------------
1 files changed, 153 insertions(+), 95 deletions(-)

through these ChangeSets:

<wim@iguana.be> (03/08/10 1.1145.1.1)
[WATCHDOG] sc520_wdt.c patch

cleanup comments and trailing spaces
add KERN_* tags to printks
added extra printk's to report what problem occured

<wim@iguana.be> (03/08/10 1.1145.1.2)
[WATCHDOG] sc520_wdt.c patch2

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

<wim@iguana.be> (03/08/10 1.1145.1.3)
[WATCHDOG] sc520_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/sc520_wdt.c b/drivers/char/watchdog/sc520_wdt.c
--- a/drivers/char/watchdog/sc520_wdt.c Sun Aug 10 12:09:36 2003
+++ b/drivers/char/watchdog/sc520_wdt.c Sun Aug 10 12:09:36 2003
@@ -1,21 +1,21 @@
/*
- * AMD Elan SC520 processor Watchdog Timer driver for Linux 2.4.x
+ * AMD Elan SC520 processor Watchdog Timer driver
*
* Based on acquirewdt.c by Alan Cox,
- * and sbc60xxwdt.c by Jakob Oestergaard <jakob@ostenfeld.dk>
- *
+ * and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net>
+ *
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
- *
- * The authors do NOT admit liability nor provide warranty for
- * any of this software. This material is provided "AS-IS" in
+ *
+ * The authors do NOT admit liability nor provide warranty for
+ * any of this software. This material is provided "AS-IS" in
* the hope that it may be useful for others.
*
* (c) Copyright 2001 Scott Jennings <linuxdrivers@oro.net>
* 9/27 - 2001 [Initial release]
- *
+ *
* Additional fixes Alan Cox
* - Fixed formatting
* - Removed debug printks
@@ -24,20 +24,15 @@
* - Used ioremap/writew/readw
* - Added NOWAYOUT support
*
- * 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.
+ * 4/12 - 2002 Changes by Rob Radez <rob@osinvestor.com>
+ * - Change comments
+ * - Eliminate fop_llseek
+ * - Change CONFIG_WATCHDOG_NOWAYOUT semantics
+ * - Add KERN_* tags to printks
+ * 09/8 - 2003 Changes by Wim Van Sebroeck <wim@iguana.be>
+ * - cleanup of trailing spaces
+ * - added extra printk's for startup problems
+ * - use module_param
*
* This WDT driver is different from most other Linux WDT
* drivers in that the driver will ping the watchdog by itself,
@@ -95,6 +90,7 @@
#define WDT_WRST_ENB 0x4000 /* [14] Watchdog Timer Reset Enable */

#define OUR_NAME "sc520_wdt"
+#define PFX OUR_NAME ": "

#define WRT_DOG(data) *wdtmrctl=data

@@ -123,9 +119,9 @@
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
*/
- if(time_before(jiffies, next_heartbeat))
+ if(time_before(jiffies, next_heartbeat))
{
/* Ping the WDT */
spin_lock(&wdt_spinlock);
@@ -137,11 +133,11 @@
timer.expires = jiffies + WDT_INTERVAL;
add_timer(&timer);
} else {
- printk(OUR_NAME ": Heartbeat lost! Will not ping the watchdog\n");
+ printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
}
}

-/*
+/*
* Utility routines
*/

@@ -168,11 +164,11 @@
next_heartbeat = jiffies + WDT_HEARTBEAT;

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

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

static void wdt_turnoff(void)
@@ -181,7 +177,7 @@
/* Stop the timer */
del_timer(&timer);
wdt_config(0);
- printk(OUR_NAME ": Watchdog timer is now disabled...\n");
+ printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
}
}

@@ -197,7 +193,7 @@
return -ESPIPE;

/* See if we got the magic character */
- if(count)
+ if(count)
{
size_t ofs;

@@ -223,7 +219,7 @@

static int fop_open(struct inode * inode, struct file * file)
{
- switch(minor(inode->i_rdev))
+ switch(minor(inode->i_rdev))
{
case WATCHDOG_MINOR:
/* Just in case we're already talking to someone... */
@@ -242,13 +238,13 @@

static int fop_close(struct inode * inode, struct file * file)
{
- if(minor(inode->i_rdev) == WATCHDOG_MINOR)
+ if(minor(inode->i_rdev) == WATCHDOG_MINOR)
{
if(wdt_expect_close)
wdt_turnoff();
else {
del_timer(&timer);
- printk(OUR_NAME ": device file closed unexpectedly. Will not stop the WDT!\n");
+ printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n");
}
}
clear_bit(0, &wdt_is_open);
@@ -262,9 +258,9 @@
{
.options = WDIOF_MAGICCLOSE,
.firmware_version = 1,
- .identity = "SC520"
+ .identity = "SC520",
};
-
+
switch(cmd)
{
default:
@@ -283,13 +279,13 @@
.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,
};

/*
@@ -299,21 +295,21 @@
static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
- if(code==SYS_DOWN || code==SYS_HALT)
+ 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.
+ * turn the timebomb registers off.
*/
-
+
static struct notifier_block wdt_notifier=
{
.notifier_call = wdt_notify_sys,
.next = NULL,
- .priority = 0
+ .priority = 0,
};

static void __exit sc520_wdt_unload(void)
@@ -339,21 +335,29 @@

rc = misc_register(&wdt_miscdev);
if (rc)
+ {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ wdt_miscdev.minor, rc);
goto err_out_region2;
+ }

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

/* get the Base Address Register */
cbar = inl_p(0xfffc);
- printk(OUR_NAME ": CBAR: 0x%08lx\n", cbar);
+ printk(KERN_INFO PFX "CBAR: 0x%08lx\n", cbar);
/* check if MMCR aliasing bit is set */
if (cbar & 0x80000000) {
- printk(OUR_NAME ": MMCR Aliasing enabled.\n");
+ printk(KERN_INFO PFX "MMCR Aliasing enabled.\n");
wdtmrctl = (__u16 *)(cbar & 0x3fffffff);
} else {
- printk(OUR_NAME "!!! WARNING !!!\n"
+ printk(KERN_INFO PFX "!!! WARNING !!!\n"
"\t MMCR Aliasing found NOT enabled!\n"
"\t Using default value of: %p\n"
"\t This has not been tested!\n"
@@ -366,7 +370,7 @@

wdtmrctl = (__u16 *)((char *)wdtmrctl + OFFS_WDTMRCTL);
wdtmrctl = ioremap((unsigned long)wdtmrctl, 2);
- printk(KERN_INFO OUR_NAME ": WDT driver for SC520 initialised.\n");
+ printk(KERN_INFO PFX "WDT driver for SC520 initialised.\n");

return 0;

diff -Nru a/drivers/char/watchdog/sc520_wdt.c b/drivers/char/watchdog/sc520_wdt.c
--- a/drivers/char/watchdog/sc520_wdt.c Sun Aug 10 12:09:56 2003
+++ b/drivers/char/watchdog/sc520_wdt.c Sun Aug 10 12:09:56 2003
@@ -29,6 +29,9 @@
* - Eliminate fop_llseek
* - Change CONFIG_WATCHDOG_NOWAYOUT semantics
* - Add KERN_* tags to printks
+ * - fix possible wdt_is_open race
+ * - Report proper capabilities in watchdog_info
+ * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETOPTIONS} ioctls
* 09/8 - 2003 Changes by Wim Van Sebroeck <wim@iguana.be>
* - cleanup of trailing spaces
* - added extra printk's for startup problems
@@ -100,7 +103,8 @@
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 spinlock_t wdt_spinlock;

#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
@@ -111,7 +115,6 @@
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

-static spinlock_t wdt_spinlock;
/*
* Whack the dog
*/
@@ -192,62 +195,56 @@
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)
{
- 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 = 1;
+ 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;
+ }
}

/* Well, anyhow someone wrote to us, we should return that favour */
next_heartbeat = jiffies + WDT_HEARTBEAT;
- return 1;
}
- return 0;
+ return count;
}

static int fop_open(struct inode * inode, struct file * file)
{
- switch(minor(inode->i_rdev))
- {
- case WATCHDOG_MINOR:
- /* 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();
- if (nowayout)
- __module_get(THIS_MODULE);
+ /* Just in case we're already talking to someone... */
+ if(test_and_set_bit(0, &wdt_is_open))
+ return -EBUSY;
+ if (nowayout)
+ __module_get(THIS_MODULE);

- return 0;
- default:
- return -ENODEV;
- }
+ /* Good, fire up the show */
+ wdt_startup();
+ return 0;
}

static int fop_close(struct inode * inode, struct file * file)
{
- if(minor(inode->i_rdev) == WATCHDOG_MINOR)
- {
- if(wdt_expect_close)
- wdt_turnoff();
- else {
- del_timer(&timer);
- printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n");
- }
+ if(wdt_expect_close == 42)
+ wdt_turnoff();
+ else {
+ del_timer(&timer);
+ 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;
}

@@ -256,7 +253,7 @@
{
static struct watchdog_info ident=
{
- .options = WDIOF_MAGICCLOSE,
+ .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "SC520",
};
@@ -267,9 +264,31 @@
return -ENOIOCTLCMD;
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;
+ }
}
}

@@ -370,7 +389,8 @@

wdtmrctl = (__u16 *)((char *)wdtmrctl + OFFS_WDTMRCTL);
wdtmrctl = ioremap((unsigned long)wdtmrctl, 2);
- printk(KERN_INFO PFX "WDT driver for SC520 initialised.\n");
+ printk(KERN_INFO PFX "WDT driver for SC520 initialised. (nowayout=%d)\n",
+ nowayout);

return 0;

diff -Nru a/drivers/char/watchdog/sc520_wdt.c b/drivers/char/watchdog/sc520_wdt.c
--- a/drivers/char/watchdog/sc520_wdt.c Sun Aug 10 12:10:19 2003
+++ b/drivers/char/watchdog/sc520_wdt.c Sun Aug 10 12:10:19 2003
@@ -31,11 +31,14 @@
* - Add KERN_* tags to printks
* - fix possible wdt_is_open race
* - Report proper capabilities in watchdog_info
- * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETOPTIONS} ioctls
+ * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETTIMEOUT,
+ * GETTIMEOUT, SETOPTIONS} ioctls
* 09/8 - 2003 Changes by Wim Van Sebroeck <wim@iguana.be>
* - cleanup of trailing spaces
* - added extra printk's for startup problems
* - use module_param
+ * - made timeout (the emulated heartbeat) a module_param
+ * - made the keepalive ping an internal subroutine
*
* This WDT driver is different from most other Linux WDT
* drivers in that the driver will ping the watchdog by itself,
@@ -75,7 +78,10 @@
* 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) ")");

/*
* AMD Elan SC520 timeout value is 492us times a power of 2 (0-7)
@@ -164,7 +170,7 @@

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

/* Start the timer */
timer.expires = jiffies + WDT_INTERVAL;
@@ -184,6 +190,11 @@
}
}

+static void wdt_keepalive(void)
+{
+ /* user land ping */
+ next_heartbeat = jiffies + (timeout * HZ);
+}

/*
* /dev/watchdog handling
@@ -217,7 +228,7 @@
}

/* Well, anyhow someone wrote to us, we should return that favour */
- next_heartbeat = jiffies + WDT_HEARTBEAT;
+ wdt_keepalive();
}
return count;
}
@@ -253,7 +264,7 @@
{
static struct watchdog_info ident=
{
- .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "SC520",
};
@@ -268,7 +279,7 @@
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
- next_heartbeat = jiffies + WDT_HEARTBEAT;
+ wdt_keepalive();
return 0;
case WDIOC_SETOPTIONS:
{
@@ -289,6 +300,22 @@

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);
}
}

@@ -348,6 +375,13 @@

spin_lock_init(&wdt_spinlock);

+ 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 = 0;
@@ -389,8 +423,8 @@

wdtmrctl = (__u16 *)((char *)wdtmrctl + OFFS_WDTMRCTL);
wdtmrctl = ioremap((unsigned long)wdtmrctl, 2);
- printk(KERN_INFO PFX "WDT driver for SC520 initialised. (nowayout=%d)\n",
- nowayout);
+ printk(KERN_INFO PFX "WDT driver for SC520 initialised. timeout=%d sec (nowayout=%d)\n",
+ timeout,nowayout);

return 0;

-
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