Commit faa8b6c3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Revert "ipmi: add new IPMI nmi watchdog handling" 



This reverts commit f64da958.

Andi Kleen is unhappy with the changes, and they really do not seem
worth it.  IPMI could use DIE_NMI_IPI instead of the new callback, even
though that ends up having its own set of problems too, mainly because
the IPMI code cannot really know the NMI was from IPMI or not.

Manually fix up conflicts in arch/x86_64/kernel/traps.c and
drivers/char/ipmi/ipmi_watchdog.c.

Cc: Andi Kleen <ak@suse.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Corey Minyard <minyard@acm.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3ec2ab55

arch/i386/kernel/traps.c

+0 −5
Original line number Diff line number Diff line
@@ -733,11 +733,6 @@ static __kprobes void default_do_nmi(struct pt_regs * regs) 
		 */

		if (nmi_watchdog_tick(regs, reason))

			return;

#endif

		if (notify_die(DIE_NMI_POST, "nmi_post", regs, reason, 2, 0)

							== NOTIFY_STOP)

			return;

#ifdef CONFIG_X86_LOCAL_APIC

		if (!do_nmi_callback(regs, smp_processor_id()))

#endif

			unknown_nmi_error(reason, regs);

arch/x86_64/kernel/traps.c

+0 −3
Original line number Diff line number Diff line
@@ -776,9 +776,6 @@ asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs) 
		 */

		if (nmi_watchdog_tick(regs,reason))

			return;

		if (notify_die(DIE_NMI_POST, "nmi_post", regs, reason, 2, 0)

								== NOTIFY_STOP)

			return;

		if (!do_nmi_callback(regs,cpu))

			unknown_nmi_error(reason, regs);

drivers/char/ipmi/ipmi_watchdog.c

+42 −92
Original line number Diff line number Diff line
@@ -50,18 +50,10 @@ 
#include <linux/poll.h>

#include <linux/string.h>

#include <linux/ctype.h>

#include <linux/delay.h>

#include <asm/atomic.h>



#ifdef CONFIG_X86

/* This is ugly, but I've determined that x86 is the only architecture

   that can reasonably support the IPMI NMI watchdog timeout at this

   time.  If another architecture adds this capability somehow, it

   will have to be a somewhat different mechanism and I have no idea

   how it will work.  So in the unlikely event that another

   architecture supports this, we can figure out a good generic

   mechanism for it at that time. */

#define HAVE_DIE_NMI_POST

#ifdef CONFIG_X86_LOCAL_APIC

#include <asm/apic.h>

#endif



#define	PFX "IPMI Watchdog: "
@@ -327,11 +319,6 @@ static unsigned char ipmi_version_minor; 
/* If a pretimeout occurs, this is used to allow only one panic to happen. */

static atomic_t preop_panic_excl = ATOMIC_INIT(-1);



#ifdef HAVE_DIE_NMI_POST

static int testing_nmi;

static int nmi_handler_registered;

#endif



static int ipmi_heartbeat(void);

static void panic_halt_ipmi_heartbeat(void);
@@ -373,10 +360,6 @@ static int i_ipmi_set_timeout(struct ipmi_smi_msg *smi_msg, 
	int                               hbnow = 0;





	/* These can be cleared as we are setting the timeout. */

	ipmi_start_timer_on_heartbeat = 0;

	pretimeout_since_last_heartbeat = 0;



	data[0] = 0;

	WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);
@@ -451,12 +434,13 @@ static int ipmi_set_timeout(int do_heartbeat) 


	wait_for_completion(&set_timeout_wait);



	mutex_unlock(&set_timeout_lock);



	if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB)

	    || ((send_heartbeat_now)

		&& (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY)))

	{

		rv = ipmi_heartbeat();

	}

	mutex_unlock(&set_timeout_lock);



out:

	return rv;
@@ -536,10 +520,12 @@ static int ipmi_heartbeat(void) 
	int                               rv;

	struct ipmi_system_interface_addr addr;



	if (ipmi_ignore_heartbeat)

	if (ipmi_ignore_heartbeat) {

		return 0;

	}



	if (ipmi_start_timer_on_heartbeat) {

		ipmi_start_timer_on_heartbeat = 0;

		ipmi_watchdog_state = action_val;

		return ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);

	} else if (pretimeout_since_last_heartbeat) {
@@ -547,6 +533,7 @@ static int ipmi_heartbeat(void) 
		   We don't want to set the action, though, we want to

		   leave that alone (thus it can't be combined with the

		   above operation. */

		pretimeout_since_last_heartbeat = 0;

		return ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY);

	}
@@ -934,45 +921,6 @@ static void ipmi_register_watchdog(int ipmi_intf) 
		printk(KERN_CRIT PFX "Unable to register misc device\n");

	}



#ifdef HAVE_DIE_NMI_POST

	if (nmi_handler_registered) {

		int old_pretimeout = pretimeout;

		int old_timeout = timeout;

		int old_preop_val = preop_val;



		/* Set the pretimeout to go off in a second and give

		   ourselves plenty of time to stop the timer. */

		ipmi_watchdog_state = WDOG_TIMEOUT_RESET;

		preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */

		pretimeout = 99;

		timeout = 100;



		testing_nmi = 1;



		rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);

		if (rv) {

			printk(KERN_WARNING PFX "Error starting timer to"

			       " test NMI: 0x%x.  The NMI pretimeout will"

			       " likely not work\n", rv);

			rv = 0;

			goto out_restore;

		}



		msleep(1500);



		if (testing_nmi != 2) {

			printk(KERN_WARNING PFX "IPMI NMI didn't seem to"

			       " occur.  The NMI pretimeout will"

			       " likely not work\n");

		}

	out_restore:

		testing_nmi = 0;

		preop_val = old_preop_val;

		pretimeout = old_pretimeout;

		timeout = old_timeout;

	}

#endif



 out:

	up_write(&register_sem);
@@ -982,10 +930,6 @@ static void ipmi_register_watchdog(int ipmi_intf) 
		ipmi_watchdog_state = action_val;

		ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB);

		printk(KERN_INFO PFX "Starting now!\n");

	} else {

		/* Stop the timer now. */

		ipmi_watchdog_state = WDOG_TIMEOUT_NONE;

		ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB);

	}

}
@@ -1022,28 +966,17 @@ static void ipmi_unregister_watchdog(int ipmi_intf) 
	up_write(&register_sem);

}



#ifdef HAVE_DIE_NMI_POST

#ifdef HAVE_NMI_HANDLER

static int

ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)

ipmi_nmi(void *dev_id, int cpu, int handled)

{

	if (val != DIE_NMI_POST)

		return NOTIFY_OK;



	if (testing_nmi) {

		testing_nmi = 2;

		return NOTIFY_STOP;

	}



        /* If we are not expecting a timeout, ignore it. */

	if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE)

		return NOTIFY_OK;



	if (preaction_val != WDOG_PRETIMEOUT_NMI)

		return NOTIFY_OK;

		return NOTIFY_DONE;



	/* If no one else handled the NMI, we assume it was the IPMI

           watchdog. */

	if (preop_val == WDOG_PREOP_PANIC) {

	if ((!handled) && (preop_val == WDOG_PREOP_PANIC)) {

		/* On some machines, the heartbeat will give

		   an error and not work unless we re-enable

		   the timer.   So do so. */
@@ -1052,12 +985,18 @@ ipmi_nmi(struct notifier_block *self, unsigned long val, void *data) 
			panic(PFX "pre-timeout");

	}



	return NOTIFY_STOP;

	return NOTIFY_DONE;

}



static struct notifier_block ipmi_nmi_handler = {

	.notifier_call = ipmi_nmi

static struct nmi_handler ipmi_nmi_handler =

{

	.link     = LIST_HEAD_INIT(ipmi_nmi_handler.link),

	.dev_name = "ipmi_watchdog",

	.dev_id   = NULL,

	.handler  = ipmi_nmi,

	.priority = 0, /* Call us last. */

};

int nmi_handler_registered;

#endif



static int wdog_reboot_handler(struct notifier_block *this,
@@ -1174,7 +1113,7 @@ static int preaction_op(const char *inval, char *outval) 
		preaction_val = WDOG_PRETIMEOUT_NONE;

	else if (strcmp(inval, "pre_smi") == 0)

		preaction_val = WDOG_PRETIMEOUT_SMI;

#ifdef HAVE_DIE_NMI_POST

#ifdef HAVE_NMI_HANDLER

	else if (strcmp(inval, "pre_nmi") == 0)

		preaction_val = WDOG_PRETIMEOUT_NMI;

#endif
@@ -1208,7 +1147,7 @@ static int preop_op(const char *inval, char *outval) 


static void check_parms(void)

{

#ifdef HAVE_DIE_NMI_POST

#ifdef HAVE_NMI_HANDLER

	int do_nmi = 0;

	int rv;
@@ -1221,9 +1160,20 @@ static void check_parms(void) 
			preop_op("preop_none", NULL);

			do_nmi = 0;

		}

#ifdef CONFIG_X86_LOCAL_APIC

		if (nmi_watchdog == NMI_IO_APIC) {

			printk(KERN_WARNING PFX "nmi_watchdog is set to IO APIC"

			       " mode (value is %d), that is incompatible"

			       " with using NMI in the IPMI watchdog."

			       " Disabling IPMI nmi pretimeout.\n",

			       nmi_watchdog);

			preaction_val = WDOG_PRETIMEOUT_NONE;

			do_nmi = 0;

		}

#endif

	}

	if (do_nmi && !nmi_handler_registered) {

		rv = register_die_notifier(&ipmi_nmi_handler);

		rv = request_nmi(&ipmi_nmi_handler);

		if (rv) {

			printk(KERN_WARNING PFX

			       "Can't register nmi handler\n");
@@ -1231,7 +1181,7 @@ static void check_parms(void) 
		} else

			nmi_handler_registered = 1;

	} else if (!do_nmi && nmi_handler_registered) {

		unregister_die_notifier(&ipmi_nmi_handler);

		release_nmi(&ipmi_nmi_handler);

		nmi_handler_registered = 0;

	}

#endif
@@ -1267,9 +1217,9 @@ static int __init ipmi_wdog_init(void) 


	rv = ipmi_smi_watcher_register(&smi_watcher);

	if (rv) {

#ifdef HAVE_DIE_NMI_POST

		if (nmi_handler_registered)

			unregister_die_notifier(&ipmi_nmi_handler);

#ifdef HAVE_NMI_HANDLER

		if (preaction_val == WDOG_PRETIMEOUT_NMI)

			release_nmi(&ipmi_nmi_handler);

#endif

		atomic_notifier_chain_unregister(&panic_notifier_list,

						 &wdog_panic_notifier);
@@ -1288,9 +1238,9 @@ static void __exit ipmi_wdog_exit(void) 
	ipmi_smi_watcher_unregister(&smi_watcher);

	ipmi_unregister_watchdog(watchdog_ifnum);



#ifdef HAVE_DIE_NMI_POST

#ifdef HAVE_NMI_HANDLER

	if (nmi_handler_registered)

		unregister_die_notifier(&ipmi_nmi_handler);

		release_nmi(&ipmi_nmi_handler);

#endif



	atomic_notifier_chain_unregister(&panic_notifier_list,

include/asm-i386/kdebug.h

+0 −1
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ enum die_val { 
	DIE_GPF,

	DIE_CALL,

	DIE_NMI_IPI,

	DIE_NMI_POST,

	DIE_PAGE_FAULT,

};

include/asm-x86_64/kdebug.h

+0 −1
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ enum die_val { 
	DIE_GPF,

	DIE_CALL,

	DIE_NMI_IPI,

	DIE_NMI_POST,

	DIE_PAGE_FAULT,

};

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