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Commit 2fbe7b25 authored by Don Zickus's avatar Don Zickus Committed by Andi Kleen
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[PATCH] i386/x86-64: Remove un/set_nmi_callback and reserve/release_lapic_nmi functions 



Removes the un/set_nmi_callback and reserve/release_lapic_nmi functions as
they are no longer needed.  The various subsystems are modified to register
with the die_notifier instead.

Also includes compile fixes by Andrew Morton.

Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 957dc87c

arch/i386/kernel/crash.c

+18 −2
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ 
#include <asm/nmi.h>

#include <asm/hw_irq.h>

#include <asm/apic.h>

#include <asm/kdebug.h>



#include <mach_ipi.h>
@@ -93,9 +95,18 @@ static void crash_save_self(struct pt_regs *regs) 
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)

static atomic_t waiting_for_crash_ipi;



static int crash_nmi_callback(struct pt_regs *regs, int cpu)

static int crash_nmi_callback(struct notifier_block *self,

			unsigned long val, void *data)

{

	struct pt_regs *regs;

	struct pt_regs fixed_regs;

	int cpu;



	if (val != DIE_NMI)

		return NOTIFY_OK;



	regs = ((struct die_args *)data)->regs;

	cpu = raw_smp_processor_id();



	/* Don't do anything if this handler is invoked on crashing cpu.

	 * Otherwise, system will completely hang. Crashing cpu can get
@@ -125,13 +136,18 @@ static void smp_send_nmi_allbutself(void) 
	send_IPI_allbutself(NMI_VECTOR);

}



static struct notifier_block crash_nmi_nb = {

	.notifier_call = crash_nmi_callback,

};



static void nmi_shootdown_cpus(void)

{

	unsigned long msecs;



	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);

	/* Would it be better to replace the trap vector here? */

	set_nmi_callback(crash_nmi_callback);

	if (register_die_notifier(&crash_nmi_nb))

		return;		/* return what? */

	/* Ensure the new callback function is set before sending

	 * out the NMI

	 */

arch/i386/kernel/nmi.c

+11 −74
Original line number Diff line number Diff line
@@ -42,20 +42,6 @@ static DEFINE_PER_CPU(unsigned long, evntsel_nmi_owner[3]); 
 */

#define NMI_MAX_COUNTER_BITS 66



/*

 * lapic_nmi_owner tracks the ownership of the lapic NMI hardware:

 * - it may be reserved by some other driver, or not

 * - when not reserved by some other driver, it may be used for

 *   the NMI watchdog, or not

 *

 * This is maintained separately from nmi_active because the NMI

 * watchdog may also be driven from the I/O APIC timer.

 */

static DEFINE_SPINLOCK(lapic_nmi_owner_lock);

static unsigned int lapic_nmi_owner;

#define LAPIC_NMI_WATCHDOG	(1<<0)

#define LAPIC_NMI_RESERVED	(1<<1)



/* nmi_active:

 * >0: the lapic NMI watchdog is active, but can be disabled

 * <0: the lapic NMI watchdog has not been set up, and cannot
@@ -325,33 +311,6 @@ static void enable_lapic_nmi_watchdog(void) 
	touch_nmi_watchdog();

}



int reserve_lapic_nmi(void)

{

	unsigned int old_owner;



	spin_lock(&lapic_nmi_owner_lock);

	old_owner = lapic_nmi_owner;

	lapic_nmi_owner |= LAPIC_NMI_RESERVED;

	spin_unlock(&lapic_nmi_owner_lock);

	if (old_owner & LAPIC_NMI_RESERVED)

		return -EBUSY;

	if (old_owner & LAPIC_NMI_WATCHDOG)

		disable_lapic_nmi_watchdog();

	return 0;

}



void release_lapic_nmi(void)

{

	unsigned int new_owner;



	spin_lock(&lapic_nmi_owner_lock);

	new_owner = lapic_nmi_owner & ~LAPIC_NMI_RESERVED;

	lapic_nmi_owner = new_owner;

	spin_unlock(&lapic_nmi_owner_lock);

	if (new_owner & LAPIC_NMI_WATCHDOG)

		enable_lapic_nmi_watchdog();

}



void disable_timer_nmi_watchdog(void)

{

	BUG_ON(nmi_watchdog != NMI_IO_APIC);
@@ -866,6 +825,15 @@ int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason) 
	return rc;

}



int do_nmi_callback(struct pt_regs * regs, int cpu)

{

#ifdef CONFIG_SYSCTL

	if (unknown_nmi_panic)

		return unknown_nmi_panic_callback(regs, cpu);

#endif

	return 0;

}



#ifdef CONFIG_SYSCTL



static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
@@ -873,37 +841,8 @@ static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) 
	unsigned char reason = get_nmi_reason();

	char buf[64];



	if (!(reason & 0xc0)) {

	sprintf(buf, "NMI received for unknown reason %02x\n", reason);

	die_nmi(regs, buf);

	}

	return 0;

}



/*

 * proc handler for /proc/sys/kernel/unknown_nmi_panic

 */

int proc_unknown_nmi_panic(ctl_table *table, int write, struct file *file,

			void __user *buffer, size_t *length, loff_t *ppos)

{

	int old_state;



	old_state = unknown_nmi_panic;

	proc_dointvec(table, write, file, buffer, length, ppos);

	if (!!old_state == !!unknown_nmi_panic)

		return 0;



	if (unknown_nmi_panic) {

		if (reserve_lapic_nmi() < 0) {

			unknown_nmi_panic = 0;

			return -EBUSY;

		} else {

			set_nmi_callback(unknown_nmi_panic_callback);

		}

	} else {

		release_lapic_nmi();

		unset_nmi_callback();

	}

	return 0;

}
@@ -917,7 +856,5 @@ EXPORT_SYMBOL(reserve_perfctr_nmi); 
EXPORT_SYMBOL(release_perfctr_nmi);

EXPORT_SYMBOL(reserve_evntsel_nmi);

EXPORT_SYMBOL(release_evntsel_nmi);

EXPORT_SYMBOL(reserve_lapic_nmi);

EXPORT_SYMBOL(release_lapic_nmi);

EXPORT_SYMBOL(disable_timer_nmi_watchdog);

EXPORT_SYMBOL(enable_timer_nmi_watchdog);

arch/i386/kernel/traps.c

+2 −21
Original line number Diff line number Diff line
@@ -706,13 +706,6 @@ void die_nmi (struct pt_regs *regs, const char *msg) 
	do_exit(SIGSEGV);

}



static int dummy_nmi_callback(struct pt_regs * regs, int cpu)

{

	return 0;

}



static nmi_callback_t nmi_callback = dummy_nmi_callback;



static void default_do_nmi(struct pt_regs * regs)

{

	unsigned char reason = 0;
@@ -732,9 +725,10 @@ static void default_do_nmi(struct pt_regs * regs) 
		 */

		if (nmi_watchdog_tick(regs, reason))

			return;

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

#endif

		if (!rcu_dereference(nmi_callback)(regs, smp_processor_id()))

			unknown_nmi_error(reason, regs);



		return;

	}

	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
@@ -765,19 +759,6 @@ fastcall void do_nmi(struct pt_regs * regs, long error_code) 
	nmi_exit();

}



void set_nmi_callback(nmi_callback_t callback)

{

	vmalloc_sync_all();

	rcu_assign_pointer(nmi_callback, callback);

}

EXPORT_SYMBOL_GPL(set_nmi_callback);



void unset_nmi_callback(void)

{

	nmi_callback = dummy_nmi_callback;

}

EXPORT_SYMBOL_GPL(unset_nmi_callback);



#ifdef CONFIG_KPROBES

fastcall void __kprobes do_int3(struct pt_regs *regs, long error_code)

{

arch/i386/oprofile/nmi_int.c

+30 −17
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <asm/nmi.h>

#include <asm/msr.h>

#include <asm/apic.h>

#include <asm/kdebug.h>

 

#include "op_counter.h"

#include "op_x86_model.h"
@@ -82,12 +83,23 @@ static void exit_driverfs(void) 
#define exit_driverfs() do { } while (0)

#endif /* CONFIG_PM */





static int nmi_callback(struct pt_regs * regs, int cpu)

int profile_exceptions_notify(struct notifier_block *self,

				unsigned long val, void *data)

{

	return model->check_ctrs(regs, &cpu_msrs[cpu]);

}

	struct die_args *args = (struct die_args *)data;

	int ret = NOTIFY_DONE;

	int cpu = smp_processor_id();



	switch(val) {

	case DIE_NMI:

		if (model->check_ctrs(args->regs, &cpu_msrs[cpu]))

			ret = NOTIFY_STOP;

		break;

	default:

		break;

	}

	return ret;

}



static void nmi_cpu_save_registers(struct op_msrs * msrs)

{
@@ -174,27 +186,29 @@ static void nmi_cpu_setup(void * dummy) 
	apic_write(APIC_LVTPC, APIC_DM_NMI);

}



static struct notifier_block profile_exceptions_nb = {

	.notifier_call = profile_exceptions_notify,

	.next = NULL,

	.priority = 0

};



static int nmi_setup(void)

{

	int err=0;



	if (!allocate_msrs())

		return -ENOMEM;



	/* We walk a thin line between law and rape here.

	 * We need to be careful to install our NMI handler

	 * without actually triggering any NMIs as this will

	 * break the core code horrifically.

	 */

	if (reserve_lapic_nmi() < 0) {

	if ((err = register_die_notifier(&profile_exceptions_nb))){

		free_msrs();

		return -EBUSY;

		return err;

	}



	/* We need to serialize save and setup for HT because the subset

	 * of msrs are distinct for save and setup operations

	 */

	on_each_cpu(nmi_save_registers, NULL, 0, 1);

	on_each_cpu(nmi_cpu_setup, NULL, 0, 1);

	set_nmi_callback(nmi_callback);

	nmi_enabled = 1;

	return 0;

}
@@ -250,8 +264,7 @@ static void nmi_shutdown(void) 
{

	nmi_enabled = 0;

	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);

	unset_nmi_callback();

	release_lapic_nmi();

	unregister_die_notifier(&profile_exceptions_nb);

	free_msrs();

}

arch/i386/oprofile/nmi_timer_int.c

+25 −8
Original line number Diff line number Diff line
@@ -17,32 +17,49 @@ 
#include <asm/nmi.h>

#include <asm/apic.h>

#include <asm/ptrace.h>

#include <asm/kdebug.h>

 

static int nmi_timer_callback(struct pt_regs * regs, int cpu)

int profile_timer_exceptions_notify(struct notifier_block *self,

				unsigned long val, void *data)

{

	oprofile_add_sample(regs, 0);

	return 1;

	struct die_args *args = (struct die_args *)data;

	int ret = NOTIFY_DONE;



	switch(val) {

	case DIE_NMI:

		oprofile_add_sample(args->regs, 0);

		ret = NOTIFY_STOP;

		break;

	default:

		break;

	}

	return ret;

}



static struct notifier_block profile_timer_exceptions_nb = {

	.notifier_call = profile_timer_exceptions_notify,

	.next = NULL,

	.priority = 0

};



static int timer_start(void)

{

	disable_timer_nmi_watchdog();

	set_nmi_callback(nmi_timer_callback);

	if (register_die_notifier(&profile_timer_exceptions_nb))

		return 1;

	return 0;

}





static void timer_stop(void)

{

	enable_timer_nmi_watchdog();

	unset_nmi_callback();

	unregister_die_notifier(&profile_timer_exceptions_nb);

	synchronize_sched();  /* Allow already-started NMIs to complete. */

}





int __init op_nmi_timer_init(struct oprofile_operations * ops)

{

	if (atomic_read(&nmi_active) <= 0)

	if ((nmi_watchdog != NMI_IO_APIC) || (atomic_read(&nmi_active) <= 0))

		return -ENODEV;



	ops->start = timer_start;