[PATCH] i386: Clean up NMI watchdog code

- Introduce a wd_ops structure
- Convert the various nmi watchdogs over to it
- This allows to split the perfctr reservation from the watchdog
setup cleanly.
- Do perfctr reservation globally as it should have always been
- Remove dead code referenced only by unused EXPORT_SYMBOLs

Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Andi Kleen 2007-05-02 19:27:20 +02:00 committed by Andi Kleen
parent e3f1caeef9
commit 09198e6850
4 changed files with 722 additions and 777 deletions

View file

@ -17,3 +17,5 @@ obj-$(CONFIG_X86_MCE) += mcheck/
obj-$(CONFIG_MTRR) += mtrr/
obj-$(CONFIG_CPU_FREQ) += cpufreq/
obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o

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@ -0,0 +1,658 @@
/* local apic based NMI watchdog for various CPUs.
This file also handles reservation of performance counters for coordination
with other users (like oprofile).
Note that these events normally don't tick when the CPU idles. This means
the frequency varies with CPU load.
Original code for K7/P6 written by Keith Owens */
#include <linux/percpu.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/smp.h>
#include <linux/nmi.h>
#include <asm/apic.h>
#include <asm/intel_arch_perfmon.h>
struct nmi_watchdog_ctlblk {
unsigned int cccr_msr;
unsigned int perfctr_msr; /* the MSR to reset in NMI handler */
unsigned int evntsel_msr; /* the MSR to select the events to handle */
};
/* Interface defining a CPU specific perfctr watchdog */
struct wd_ops {
int (*reserve)(void);
void (*unreserve)(void);
int (*setup)(unsigned nmi_hz);
void (*rearm)(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz);
void (*stop)(void *);
unsigned perfctr;
unsigned evntsel;
u64 checkbit;
};
static struct wd_ops *wd_ops;
/* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's
* offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now)
*/
#define NMI_MAX_COUNTER_BITS 66
/* perfctr_nmi_owner tracks the ownership of the perfctr registers:
* evtsel_nmi_owner tracks the ownership of the event selection
* - different performance counters/ event selection may be reserved for
* different subsystems this reservation system just tries to coordinate
* things a little
*/
static DECLARE_BITMAP(perfctr_nmi_owner, NMI_MAX_COUNTER_BITS);
static DECLARE_BITMAP(evntsel_nmi_owner, NMI_MAX_COUNTER_BITS);
static DEFINE_PER_CPU(struct nmi_watchdog_ctlblk, nmi_watchdog_ctlblk);
/* converts an msr to an appropriate reservation bit */
static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
{
return wd_ops ? msr - wd_ops->perfctr : 0;
}
/* converts an msr to an appropriate reservation bit */
/* returns the bit offset of the event selection register */
static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr)
{
return wd_ops ? msr - wd_ops->evntsel : 0;
}
/* checks for a bit availability (hack for oprofile) */
int avail_to_resrv_perfctr_nmi_bit(unsigned int counter)
{
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
return (!test_bit(counter, perfctr_nmi_owner));
}
/* checks the an msr for availability */
int avail_to_resrv_perfctr_nmi(unsigned int msr)
{
unsigned int counter;
counter = nmi_perfctr_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
return (!test_bit(counter, perfctr_nmi_owner));
}
int reserve_perfctr_nmi(unsigned int msr)
{
unsigned int counter;
counter = nmi_perfctr_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
if (!test_and_set_bit(counter, perfctr_nmi_owner))
return 1;
return 0;
}
void release_perfctr_nmi(unsigned int msr)
{
unsigned int counter;
counter = nmi_perfctr_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
clear_bit(counter, perfctr_nmi_owner);
}
int reserve_evntsel_nmi(unsigned int msr)
{
unsigned int counter;
counter = nmi_evntsel_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
if (!test_and_set_bit(counter, evntsel_nmi_owner))
return 1;
return 0;
}
void release_evntsel_nmi(unsigned int msr)
{
unsigned int counter;
counter = nmi_evntsel_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
clear_bit(counter, evntsel_nmi_owner);
}
EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi);
EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi_bit);
EXPORT_SYMBOL(reserve_perfctr_nmi);
EXPORT_SYMBOL(release_perfctr_nmi);
EXPORT_SYMBOL(reserve_evntsel_nmi);
EXPORT_SYMBOL(release_evntsel_nmi);
void disable_lapic_nmi_watchdog(void)
{
BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
if (atomic_read(&nmi_active) <= 0)
return;
on_each_cpu(wd_ops->stop, NULL, 0, 1);
wd_ops->unreserve();
BUG_ON(atomic_read(&nmi_active) != 0);
}
void enable_lapic_nmi_watchdog(void)
{
BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
/* are we already enabled */
if (atomic_read(&nmi_active) != 0)
return;
/* are we lapic aware */
if (!wd_ops)
return;
if (!wd_ops->reserve()) {
printk(KERN_ERR "NMI watchdog: cannot reserve perfctrs\n");
return;
}
on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1);
touch_nmi_watchdog();
}
/*
* Activate the NMI watchdog via the local APIC.
*/
static unsigned int adjust_for_32bit_ctr(unsigned int hz)
{
u64 counter_val;
unsigned int retval = hz;
/*
* On Intel CPUs with P6/ARCH_PERFMON only 32 bits in the counter
* are writable, with higher bits sign extending from bit 31.
* So, we can only program the counter with 31 bit values and
* 32nd bit should be 1, for 33.. to be 1.
* Find the appropriate nmi_hz
*/
counter_val = (u64)cpu_khz * 1000;
do_div(counter_val, retval);
if (counter_val > 0x7fffffffULL) {
u64 count = (u64)cpu_khz * 1000;
do_div(count, 0x7fffffffUL);
retval = count + 1;
}
return retval;
}
static void
write_watchdog_counter(unsigned int perfctr_msr, const char *descr, unsigned nmi_hz)
{
u64 count = (u64)cpu_khz * 1000;
do_div(count, nmi_hz);
if(descr)
Dprintk("setting %s to -0x%08Lx\n", descr, count);
wrmsrl(perfctr_msr, 0 - count);
}
static void write_watchdog_counter32(unsigned int perfctr_msr,
const char *descr, unsigned nmi_hz)
{
u64 count = (u64)cpu_khz * 1000;
do_div(count, nmi_hz);
if(descr)
Dprintk("setting %s to -0x%08Lx\n", descr, count);
wrmsr(perfctr_msr, (u32)(-count), 0);
}
/* AMD K7/K8/Family10h/Family11h support. AMD keeps this interface
nicely stable so there is not much variety */
#define K7_EVNTSEL_ENABLE (1 << 22)
#define K7_EVNTSEL_INT (1 << 20)
#define K7_EVNTSEL_OS (1 << 17)
#define K7_EVNTSEL_USR (1 << 16)
#define K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING 0x76
#define K7_NMI_EVENT K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING
static int setup_k7_watchdog(unsigned nmi_hz)
{
unsigned int perfctr_msr, evntsel_msr;
unsigned int evntsel;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
perfctr_msr = MSR_K7_PERFCTR0;
evntsel_msr = MSR_K7_EVNTSEL0;
wrmsrl(perfctr_msr, 0UL);
evntsel = K7_EVNTSEL_INT
| K7_EVNTSEL_OS
| K7_EVNTSEL_USR
| K7_NMI_EVENT;
/* setup the timer */
wrmsr(evntsel_msr, evntsel, 0);
write_watchdog_counter(perfctr_msr, "K7_PERFCTR0",nmi_hz);
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= K7_EVNTSEL_ENABLE;
wrmsr(evntsel_msr, evntsel, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
return 1;
}
static void single_msr_stop_watchdog(void *arg)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
wrmsr(wd->evntsel_msr, 0, 0);
}
static int single_msr_reserve(void)
{
if (!reserve_perfctr_nmi(wd_ops->perfctr))
return 0;
if (!reserve_evntsel_nmi(wd_ops->evntsel)) {
release_perfctr_nmi(wd_ops->perfctr);
return 0;
}
return 1;
}
static void single_msr_unreserve(void)
{
release_evntsel_nmi(wd_ops->perfctr);
release_perfctr_nmi(wd_ops->evntsel);
}
static void single_msr_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
{
/* start the cycle over again */
write_watchdog_counter(wd->perfctr_msr, NULL, nmi_hz);
}
static struct wd_ops k7_wd_ops = {
.reserve = single_msr_reserve,
.unreserve = single_msr_unreserve,
.setup = setup_k7_watchdog,
.rearm = single_msr_rearm,
.stop = single_msr_stop_watchdog,
.perfctr = MSR_K7_PERFCTR0,
.evntsel = MSR_K7_EVNTSEL0,
.checkbit = 1ULL<<63,
};
/* Intel Model 6 (PPro+,P2,P3,P-M,Core1) */
#define P6_EVNTSEL0_ENABLE (1 << 22)
#define P6_EVNTSEL_INT (1 << 20)
#define P6_EVNTSEL_OS (1 << 17)
#define P6_EVNTSEL_USR (1 << 16)
#define P6_EVENT_CPU_CLOCKS_NOT_HALTED 0x79
#define P6_NMI_EVENT P6_EVENT_CPU_CLOCKS_NOT_HALTED
static int setup_p6_watchdog(unsigned nmi_hz)
{
unsigned int perfctr_msr, evntsel_msr;
unsigned int evntsel;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
perfctr_msr = MSR_P6_PERFCTR0;
evntsel_msr = MSR_P6_EVNTSEL0;
wrmsrl(perfctr_msr, 0UL);
evntsel = P6_EVNTSEL_INT
| P6_EVNTSEL_OS
| P6_EVNTSEL_USR
| P6_NMI_EVENT;
/* setup the timer */
wrmsr(evntsel_msr, evntsel, 0);
nmi_hz = adjust_for_32bit_ctr(nmi_hz);
write_watchdog_counter32(perfctr_msr, "P6_PERFCTR0",nmi_hz);
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= P6_EVNTSEL0_ENABLE;
wrmsr(evntsel_msr, evntsel, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
return 1;
}
static void p6_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
{
/* P6 based Pentium M need to re-unmask
* the apic vector but it doesn't hurt
* other P6 variant.
* ArchPerfom/Core Duo also needs this */
apic_write(APIC_LVTPC, APIC_DM_NMI);
/* P6/ARCH_PERFMON has 32 bit counter write */
write_watchdog_counter32(wd->perfctr_msr, NULL,nmi_hz);
}
static struct wd_ops p6_wd_ops = {
.reserve = single_msr_reserve,
.unreserve = single_msr_unreserve,
.setup = setup_p6_watchdog,
.rearm = p6_rearm,
.stop = single_msr_stop_watchdog,
.perfctr = MSR_P6_PERFCTR0,
.evntsel = MSR_P6_EVNTSEL0,
.checkbit = 1ULL<<39,
};
/* Intel P4 performance counters. By far the most complicated of all. */
#define MSR_P4_MISC_ENABLE_PERF_AVAIL (1<<7)
#define P4_ESCR_EVENT_SELECT(N) ((N)<<25)
#define P4_ESCR_OS (1<<3)
#define P4_ESCR_USR (1<<2)
#define P4_CCCR_OVF_PMI0 (1<<26)
#define P4_CCCR_OVF_PMI1 (1<<27)
#define P4_CCCR_THRESHOLD(N) ((N)<<20)
#define P4_CCCR_COMPLEMENT (1<<19)
#define P4_CCCR_COMPARE (1<<18)
#define P4_CCCR_REQUIRED (3<<16)
#define P4_CCCR_ESCR_SELECT(N) ((N)<<13)
#define P4_CCCR_ENABLE (1<<12)
#define P4_CCCR_OVF (1<<31)
/* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter
CRU_ESCR0 (with any non-null event selector) through a complemented
max threshold. [IA32-Vol3, Section 14.9.9] */
static int setup_p4_watchdog(unsigned nmi_hz)
{
unsigned int perfctr_msr, evntsel_msr, cccr_msr;
unsigned int evntsel, cccr_val;
unsigned int misc_enable, dummy;
unsigned int ht_num;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
rdmsr(MSR_IA32_MISC_ENABLE, misc_enable, dummy);
if (!(misc_enable & MSR_P4_MISC_ENABLE_PERF_AVAIL))
return 0;
#ifdef CONFIG_SMP
/* detect which hyperthread we are on */
if (smp_num_siblings == 2) {
unsigned int ebx, apicid;
ebx = cpuid_ebx(1);
apicid = (ebx >> 24) & 0xff;
ht_num = apicid & 1;
} else
#endif
ht_num = 0;
/* performance counters are shared resources
* assign each hyperthread its own set
* (re-use the ESCR0 register, seems safe
* and keeps the cccr_val the same)
*/
if (!ht_num) {
/* logical cpu 0 */
perfctr_msr = MSR_P4_IQ_PERFCTR0;
evntsel_msr = MSR_P4_CRU_ESCR0;
cccr_msr = MSR_P4_IQ_CCCR0;
cccr_val = P4_CCCR_OVF_PMI0 | P4_CCCR_ESCR_SELECT(4);
} else {
/* logical cpu 1 */
perfctr_msr = MSR_P4_IQ_PERFCTR1;
evntsel_msr = MSR_P4_CRU_ESCR0;
cccr_msr = MSR_P4_IQ_CCCR1;
cccr_val = P4_CCCR_OVF_PMI1 | P4_CCCR_ESCR_SELECT(4);
}
evntsel = P4_ESCR_EVENT_SELECT(0x3F)
| P4_ESCR_OS
| P4_ESCR_USR;
cccr_val |= P4_CCCR_THRESHOLD(15)
| P4_CCCR_COMPLEMENT
| P4_CCCR_COMPARE
| P4_CCCR_REQUIRED;
wrmsr(evntsel_msr, evntsel, 0);
wrmsr(cccr_msr, cccr_val, 0);
write_watchdog_counter(perfctr_msr, "P4_IQ_COUNTER0", nmi_hz);
apic_write(APIC_LVTPC, APIC_DM_NMI);
cccr_val |= P4_CCCR_ENABLE;
wrmsr(cccr_msr, cccr_val, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = cccr_msr;
return 1;
}
static void stop_p4_watchdog(void *arg)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
wrmsr(wd->cccr_msr, 0, 0);
wrmsr(wd->evntsel_msr, 0, 0);
}
static int p4_reserve(void)
{
if (!reserve_perfctr_nmi(MSR_P4_IQ_PERFCTR0))
return 0;
#ifdef CONFIG_SMP
if (smp_num_siblings > 1 && !reserve_perfctr_nmi(MSR_P4_IQ_PERFCTR1))
goto fail1;
#endif
if (!reserve_evntsel_nmi(MSR_P4_CRU_ESCR0))
goto fail2;
/* RED-PEN why is ESCR1 not reserved here? */
return 1;
fail2:
#ifdef CONFIG_SMP
if (smp_num_siblings > 1)
release_perfctr_nmi(MSR_P4_IQ_PERFCTR1);
fail1:
#endif
release_perfctr_nmi(MSR_P4_IQ_PERFCTR0);
return 0;
}
static void p4_unreserve(void)
{
#ifdef CONFIG_SMP
if (smp_num_siblings > 1)
release_evntsel_nmi(MSR_P4_IQ_PERFCTR1);
#endif
release_evntsel_nmi(MSR_P4_IQ_PERFCTR0);
release_perfctr_nmi(MSR_P4_CRU_ESCR0);
}
static void p4_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
{
unsigned dummy;
/*
* P4 quirks:
* - An overflown perfctr will assert its interrupt
* until the OVF flag in its CCCR is cleared.
* - LVTPC is masked on interrupt and must be
* unmasked by the LVTPC handler.
*/
rdmsrl(wd->cccr_msr, dummy);
dummy &= ~P4_CCCR_OVF;
wrmsrl(wd->cccr_msr, dummy);
apic_write(APIC_LVTPC, APIC_DM_NMI);
/* start the cycle over again */
write_watchdog_counter(wd->perfctr_msr, NULL, nmi_hz);
}
static struct wd_ops p4_wd_ops = {
.reserve = p4_reserve,
.unreserve = p4_unreserve,
.setup = setup_p4_watchdog,
.rearm = p4_rearm,
.stop = stop_p4_watchdog,
/* RED-PEN this is wrong for the other sibling */
.perfctr = MSR_P4_BPU_PERFCTR0,
.evntsel = MSR_P4_BSU_ESCR0,
.checkbit = 1ULL<<39,
};
/* Watchdog using the Intel architected PerfMon. Used for Core2 and hopefully
all future Intel CPUs. */
#define ARCH_PERFMON_NMI_EVENT_SEL ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL
#define ARCH_PERFMON_NMI_EVENT_UMASK ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK
static int setup_intel_arch_watchdog(unsigned nmi_hz)
{
unsigned int ebx;
union cpuid10_eax eax;
unsigned int unused;
unsigned int perfctr_msr, evntsel_msr;
unsigned int evntsel;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
/*
* Check whether the Architectural PerfMon supports
* Unhalted Core Cycles Event or not.
* NOTE: Corresponding bit = 0 in ebx indicates event present.
*/
cpuid(10, &(eax.full), &ebx, &unused, &unused);
if ((eax.split.mask_length < (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX+1)) ||
(ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT))
return 0;
perfctr_msr = MSR_ARCH_PERFMON_PERFCTR1;
evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL1;
wrmsrl(perfctr_msr, 0UL);
evntsel = ARCH_PERFMON_EVENTSEL_INT
| ARCH_PERFMON_EVENTSEL_OS
| ARCH_PERFMON_EVENTSEL_USR
| ARCH_PERFMON_NMI_EVENT_SEL
| ARCH_PERFMON_NMI_EVENT_UMASK;
/* setup the timer */
wrmsr(evntsel_msr, evntsel, 0);
nmi_hz = adjust_for_32bit_ctr(nmi_hz);
write_watchdog_counter32(perfctr_msr, "INTEL_ARCH_PERFCTR0", nmi_hz);
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= ARCH_PERFMON_EVENTSEL0_ENABLE;
wrmsr(evntsel_msr, evntsel, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
wd_ops->checkbit = 1ULL << (eax.split.bit_width - 1);
return 1;
}
static struct wd_ops intel_arch_wd_ops = {
.reserve = single_msr_reserve,
.unreserve = single_msr_unreserve,
.setup = setup_intel_arch_watchdog,
.rearm = p6_rearm,
.stop = single_msr_stop_watchdog,
.perfctr = MSR_ARCH_PERFMON_PERFCTR0,
.evntsel = MSR_ARCH_PERFMON_EVENTSEL0,
};
static void probe_nmi_watchdog(void)
{
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15 &&
boot_cpu_data.x86 != 16)
return;
wd_ops = &k7_wd_ops;
break;
case X86_VENDOR_INTEL:
if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
wd_ops = &intel_arch_wd_ops;
break;
}
switch (boot_cpu_data.x86) {
case 6:
if (boot_cpu_data.x86_model > 0xd)
return;
wd_ops = &p6_wd_ops;
break;
case 15:
if (boot_cpu_data.x86_model > 0x4)
return;
wd_ops = &p4_wd_ops;
break;
default:
return;
}
break;
}
}
/* Interface to nmi.c */
int lapic_watchdog_init(unsigned nmi_hz)
{
if (!wd_ops) {
probe_nmi_watchdog();
if (!wd_ops)
return -1;
}
if (!(wd_ops->setup(nmi_hz))) {
printk(KERN_ERR "Cannot setup NMI watchdog on CPU %d\n",
raw_smp_processor_id());
return -1;
}
return 0;
}
void lapic_watchdog_stop(void)
{
if (wd_ops)
wd_ops->stop(NULL);
}
unsigned lapic_adjust_nmi_hz(unsigned hz)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
if (wd->perfctr_msr == MSR_P6_PERFCTR0 ||
wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1)
hz = adjust_for_32bit_ctr(hz);
return hz;
}
int lapic_wd_event(unsigned nmi_hz)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
u64 ctr;
rdmsrl(wd->perfctr_msr, ctr);
if (ctr & wd_ops->checkbit) { /* perfctr still running? */
return 0;
}
wd_ops->rearm(wd, nmi_hz);
return 1;
}
int lapic_watchdog_ok(void)
{
return wd_ops != NULL;
}

View file

@ -20,7 +20,6 @@
#include <linux/sysdev.h>
#include <linux/sysctl.h>
#include <linux/percpu.h>
#include <linux/dmi.h>
#include <linux/kprobes.h>
#include <linux/cpumask.h>
#include <linux/kernel_stat.h>
@ -28,30 +27,14 @@
#include <asm/smp.h>
#include <asm/nmi.h>
#include <asm/kdebug.h>
#include <asm/intel_arch_perfmon.h>
#include "mach_traps.h"
int unknown_nmi_panic;
int nmi_watchdog_enabled;
/* perfctr_nmi_owner tracks the ownership of the perfctr registers:
* evtsel_nmi_owner tracks the ownership of the event selection
* - different performance counters/ event selection may be reserved for
* different subsystems this reservation system just tries to coordinate
* things a little
*/
/* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's
* offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now)
*/
#define NMI_MAX_COUNTER_BITS 66
#define NMI_MAX_COUNTER_LONGS BITS_TO_LONGS(NMI_MAX_COUNTER_BITS)
static DEFINE_PER_CPU(unsigned long, perfctr_nmi_owner[NMI_MAX_COUNTER_LONGS]);
static DEFINE_PER_CPU(unsigned long, evntsel_nmi_owner[NMI_MAX_COUNTER_LONGS]);
static cpumask_t backtrace_mask = CPU_MASK_NONE;
/* 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
@ -63,203 +46,11 @@ atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */
unsigned int nmi_watchdog = NMI_DEFAULT;
static unsigned int nmi_hz = HZ;
struct nmi_watchdog_ctlblk {
int enabled;
u64 check_bit;
unsigned int cccr_msr;
unsigned int perfctr_msr; /* the MSR to reset in NMI handler */
unsigned int evntsel_msr; /* the MSR to select the events to handle */
};
static DEFINE_PER_CPU(struct nmi_watchdog_ctlblk, nmi_watchdog_ctlblk);
static DEFINE_PER_CPU(short, wd_enabled);
/* local prototypes */
static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu);
/* converts an msr to an appropriate reservation bit */
static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
{
/* returns the bit offset of the performance counter register */
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
return (msr - MSR_K7_PERFCTR0);
case X86_VENDOR_INTEL:
if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
return (msr - MSR_ARCH_PERFMON_PERFCTR0);
switch (boot_cpu_data.x86) {
case 6:
return (msr - MSR_P6_PERFCTR0);
case 15:
return (msr - MSR_P4_BPU_PERFCTR0);
}
}
return 0;
}
/* converts an msr to an appropriate reservation bit */
static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr)
{
/* returns the bit offset of the event selection register */
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
return (msr - MSR_K7_EVNTSEL0);
case X86_VENDOR_INTEL:
if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
return (msr - MSR_ARCH_PERFMON_EVENTSEL0);
switch (boot_cpu_data.x86) {
case 6:
return (msr - MSR_P6_EVNTSEL0);
case 15:
return (msr - MSR_P4_BSU_ESCR0);
}
}
return 0;
}
/* checks for a bit availability (hack for oprofile) */
int avail_to_resrv_perfctr_nmi_bit(unsigned int counter)
{
int cpu;
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
for_each_possible_cpu (cpu) {
if (test_bit(counter, &per_cpu(perfctr_nmi_owner, cpu)[0]))
return 0;
}
return 1;
}
/* checks the an msr for availability */
int avail_to_resrv_perfctr_nmi(unsigned int msr)
{
unsigned int counter;
int cpu;
counter = nmi_perfctr_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
for_each_possible_cpu (cpu) {
if (test_bit(counter, &per_cpu(perfctr_nmi_owner, cpu)[0]))
return 0;
}
return 1;
}
static int __reserve_perfctr_nmi(int cpu, unsigned int msr)
{
unsigned int counter;
if (cpu < 0)
cpu = smp_processor_id();
counter = nmi_perfctr_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
if (!test_and_set_bit(counter, &per_cpu(perfctr_nmi_owner, cpu)[0]))
return 1;
return 0;
}
static void __release_perfctr_nmi(int cpu, unsigned int msr)
{
unsigned int counter;
if (cpu < 0)
cpu = smp_processor_id();
counter = nmi_perfctr_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
clear_bit(counter, &per_cpu(perfctr_nmi_owner, cpu)[0]);
}
int reserve_perfctr_nmi(unsigned int msr)
{
int cpu, i;
for_each_possible_cpu (cpu) {
if (!__reserve_perfctr_nmi(cpu, msr)) {
for_each_possible_cpu (i) {
if (i >= cpu)
break;
__release_perfctr_nmi(i, msr);
}
return 0;
}
}
return 1;
}
void release_perfctr_nmi(unsigned int msr)
{
int cpu;
for_each_possible_cpu (cpu) {
__release_perfctr_nmi(cpu, msr);
}
}
int __reserve_evntsel_nmi(int cpu, unsigned int msr)
{
unsigned int counter;
if (cpu < 0)
cpu = smp_processor_id();
counter = nmi_evntsel_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
if (!test_and_set_bit(counter, &per_cpu(evntsel_nmi_owner, cpu)[0]))
return 1;
return 0;
}
static void __release_evntsel_nmi(int cpu, unsigned int msr)
{
unsigned int counter;
if (cpu < 0)
cpu = smp_processor_id();
counter = nmi_evntsel_msr_to_bit(msr);
BUG_ON(counter > NMI_MAX_COUNTER_BITS);
clear_bit(counter, &per_cpu(evntsel_nmi_owner, cpu)[0]);
}
int reserve_evntsel_nmi(unsigned int msr)
{
int cpu, i;
for_each_possible_cpu (cpu) {
if (!__reserve_evntsel_nmi(cpu, msr)) {
for_each_possible_cpu (i) {
if (i >= cpu)
break;
__release_evntsel_nmi(i, msr);
}
return 0;
}
}
return 1;
}
void release_evntsel_nmi(unsigned int msr)
{
int cpu;
for_each_possible_cpu (cpu) {
__release_evntsel_nmi(cpu, msr);
}
}
static __cpuinit inline int nmi_known_cpu(void)
{
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6)
|| (boot_cpu_data.x86 == 16));
case X86_VENDOR_INTEL:
if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
return 1;
else
return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6));
}
return 0;
}
static int endflag __initdata = 0;
#ifdef CONFIG_SMP
@ -281,28 +72,6 @@ static __init void nmi_cpu_busy(void *data)
}
#endif
static unsigned int adjust_for_32bit_ctr(unsigned int hz)
{
u64 counter_val;
unsigned int retval = hz;
/*
* On Intel CPUs with P6/ARCH_PERFMON only 32 bits in the counter
* are writable, with higher bits sign extending from bit 31.
* So, we can only program the counter with 31 bit values and
* 32nd bit should be 1, for 33.. to be 1.
* Find the appropriate nmi_hz
*/
counter_val = (u64)cpu_khz * 1000;
do_div(counter_val, retval);
if (counter_val > 0x7fffffffULL) {
u64 count = (u64)cpu_khz * 1000;
do_div(count, 0x7fffffffUL);
retval = count + 1;
}
return retval;
}
static int __init check_nmi_watchdog(void)
{
unsigned int *prev_nmi_count;
@ -335,14 +104,14 @@ static int __init check_nmi_watchdog(void)
if (!cpu_isset(cpu, cpu_callin_map))
continue;
#endif
if (!per_cpu(nmi_watchdog_ctlblk, cpu).enabled)
if (!per_cpu(wd_enabled, cpu))
continue;
if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {
printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n",
cpu,
prev_nmi_count[cpu],
nmi_count(cpu));
per_cpu(nmi_watchdog_ctlblk, cpu).enabled = 0;
per_cpu(wd_enabled, cpu) = 0;
atomic_dec(&nmi_active);
}
}
@ -356,16 +125,8 @@ static int __init check_nmi_watchdog(void)
/* now that we know it works we can reduce NMI frequency to
something more reasonable; makes a difference in some configs */
if (nmi_watchdog == NMI_LOCAL_APIC) {
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
nmi_hz = 1;
if (wd->perfctr_msr == MSR_P6_PERFCTR0 ||
wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1) {
nmi_hz = adjust_for_32bit_ctr(nmi_hz);
}
}
if (nmi_watchdog == NMI_LOCAL_APIC)
nmi_hz = lapic_adjust_nmi_hz(1);
kfree(prev_nmi_count);
return 0;
@ -388,85 +149,8 @@ static int __init setup_nmi_watchdog(char *str)
__setup("nmi_watchdog=", setup_nmi_watchdog);
static void disable_lapic_nmi_watchdog(void)
{
BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
if (atomic_read(&nmi_active) <= 0)
return;
on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1);
BUG_ON(atomic_read(&nmi_active) != 0);
}
static void enable_lapic_nmi_watchdog(void)
{
BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
/* are we already enabled */
if (atomic_read(&nmi_active) != 0)
return;
/* are we lapic aware */
if (nmi_known_cpu() <= 0)
return;
on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1);
touch_nmi_watchdog();
}
void disable_timer_nmi_watchdog(void)
{
BUG_ON(nmi_watchdog != NMI_IO_APIC);
if (atomic_read(&nmi_active) <= 0)
return;
disable_irq(0);
on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1);
BUG_ON(atomic_read(&nmi_active) != 0);
}
void enable_timer_nmi_watchdog(void)
{
BUG_ON(nmi_watchdog != NMI_IO_APIC);
if (atomic_read(&nmi_active) == 0) {
touch_nmi_watchdog();
on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1);
enable_irq(0);
}
}
static void __acpi_nmi_disable(void *__unused)
{
apic_write_around(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
}
/*
* Disable timer based NMIs on all CPUs:
*/
void acpi_nmi_disable(void)
{
if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
on_each_cpu(__acpi_nmi_disable, NULL, 0, 1);
}
static void __acpi_nmi_enable(void *__unused)
{
apic_write_around(APIC_LVT0, APIC_DM_NMI);
}
/*
* Enable timer based NMIs on all CPUs:
*/
void acpi_nmi_enable(void)
{
if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
on_each_cpu(__acpi_nmi_enable, NULL, 0, 1);
}
/* Suspend/resume support */
#ifdef CONFIG_PM
@ -513,7 +197,7 @@ static int __init init_lapic_nmi_sysfs(void)
if (nmi_watchdog != NMI_LOCAL_APIC)
return 0;
if ( atomic_read(&nmi_active) < 0 )
if (atomic_read(&nmi_active) < 0)
return 0;
error = sysdev_class_register(&nmi_sysclass);
@ -526,433 +210,69 @@ late_initcall(init_lapic_nmi_sysfs);
#endif /* CONFIG_PM */
static void __acpi_nmi_enable(void *__unused)
{
apic_write_around(APIC_LVT0, APIC_DM_NMI);
}
/*
* Activate the NMI watchdog via the local APIC.
* Original code written by Keith Owens.
* Enable timer based NMIs on all CPUs:
*/
static void write_watchdog_counter(unsigned int perfctr_msr, const char *descr)
void acpi_nmi_enable(void)
{
u64 count = (u64)cpu_khz * 1000;
do_div(count, nmi_hz);
if(descr)
Dprintk("setting %s to -0x%08Lx\n", descr, count);
wrmsrl(perfctr_msr, 0 - count);
if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
on_each_cpu(__acpi_nmi_enable, NULL, 0, 1);
}
static void write_watchdog_counter32(unsigned int perfctr_msr,
const char *descr)
static void __acpi_nmi_disable(void *__unused)
{
u64 count = (u64)cpu_khz * 1000;
do_div(count, nmi_hz);
if(descr)
Dprintk("setting %s to -0x%08Lx\n", descr, count);
wrmsr(perfctr_msr, (u32)(-count), 0);
apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
}
/* Note that these events don't tick when the CPU idles. This means
the frequency varies with CPU load. */
#define K7_EVNTSEL_ENABLE (1 << 22)
#define K7_EVNTSEL_INT (1 << 20)
#define K7_EVNTSEL_OS (1 << 17)
#define K7_EVNTSEL_USR (1 << 16)
#define K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING 0x76
#define K7_NMI_EVENT K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING
static int setup_k7_watchdog(void)
/*
* Disable timer based NMIs on all CPUs:
*/
void acpi_nmi_disable(void)
{
unsigned int perfctr_msr, evntsel_msr;
unsigned int evntsel;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
perfctr_msr = MSR_K7_PERFCTR0;
evntsel_msr = MSR_K7_EVNTSEL0;
if (!__reserve_perfctr_nmi(-1, perfctr_msr))
goto fail;
if (!__reserve_evntsel_nmi(-1, evntsel_msr))
goto fail1;
wrmsrl(perfctr_msr, 0UL);
evntsel = K7_EVNTSEL_INT
| K7_EVNTSEL_OS
| K7_EVNTSEL_USR
| K7_NMI_EVENT;
/* setup the timer */
wrmsr(evntsel_msr, evntsel, 0);
write_watchdog_counter(perfctr_msr, "K7_PERFCTR0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= K7_EVNTSEL_ENABLE;
wrmsr(evntsel_msr, evntsel, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
wd->check_bit = 1ULL<<63;
return 1;
fail1:
__release_perfctr_nmi(-1, perfctr_msr);
fail:
return 0;
}
static void stop_k7_watchdog(void)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
wrmsr(wd->evntsel_msr, 0, 0);
__release_evntsel_nmi(-1, wd->evntsel_msr);
__release_perfctr_nmi(-1, wd->perfctr_msr);
}
#define P6_EVNTSEL0_ENABLE (1 << 22)
#define P6_EVNTSEL_INT (1 << 20)
#define P6_EVNTSEL_OS (1 << 17)
#define P6_EVNTSEL_USR (1 << 16)
#define P6_EVENT_CPU_CLOCKS_NOT_HALTED 0x79
#define P6_NMI_EVENT P6_EVENT_CPU_CLOCKS_NOT_HALTED
static int setup_p6_watchdog(void)
{
unsigned int perfctr_msr, evntsel_msr;
unsigned int evntsel;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
perfctr_msr = MSR_P6_PERFCTR0;
evntsel_msr = MSR_P6_EVNTSEL0;
if (!__reserve_perfctr_nmi(-1, perfctr_msr))
goto fail;
if (!__reserve_evntsel_nmi(-1, evntsel_msr))
goto fail1;
wrmsrl(perfctr_msr, 0UL);
evntsel = P6_EVNTSEL_INT
| P6_EVNTSEL_OS
| P6_EVNTSEL_USR
| P6_NMI_EVENT;
/* setup the timer */
wrmsr(evntsel_msr, evntsel, 0);
nmi_hz = adjust_for_32bit_ctr(nmi_hz);
write_watchdog_counter32(perfctr_msr, "P6_PERFCTR0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= P6_EVNTSEL0_ENABLE;
wrmsr(evntsel_msr, evntsel, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
wd->check_bit = 1ULL<<39;
return 1;
fail1:
__release_perfctr_nmi(-1, perfctr_msr);
fail:
return 0;
}
static void stop_p6_watchdog(void)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
wrmsr(wd->evntsel_msr, 0, 0);
__release_evntsel_nmi(-1, wd->evntsel_msr);
__release_perfctr_nmi(-1, wd->perfctr_msr);
}
/* Note that these events don't tick when the CPU idles. This means
the frequency varies with CPU load. */
#define MSR_P4_MISC_ENABLE_PERF_AVAIL (1<<7)
#define P4_ESCR_EVENT_SELECT(N) ((N)<<25)
#define P4_ESCR_OS (1<<3)
#define P4_ESCR_USR (1<<2)
#define P4_CCCR_OVF_PMI0 (1<<26)
#define P4_CCCR_OVF_PMI1 (1<<27)
#define P4_CCCR_THRESHOLD(N) ((N)<<20)
#define P4_CCCR_COMPLEMENT (1<<19)
#define P4_CCCR_COMPARE (1<<18)
#define P4_CCCR_REQUIRED (3<<16)
#define P4_CCCR_ESCR_SELECT(N) ((N)<<13)
#define P4_CCCR_ENABLE (1<<12)
#define P4_CCCR_OVF (1<<31)
/* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter
CRU_ESCR0 (with any non-null event selector) through a complemented
max threshold. [IA32-Vol3, Section 14.9.9] */
static int setup_p4_watchdog(void)
{
unsigned int perfctr_msr, evntsel_msr, cccr_msr;
unsigned int evntsel, cccr_val;
unsigned int misc_enable, dummy;
unsigned int ht_num;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
rdmsr(MSR_IA32_MISC_ENABLE, misc_enable, dummy);
if (!(misc_enable & MSR_P4_MISC_ENABLE_PERF_AVAIL))
return 0;
#ifdef CONFIG_SMP
/* detect which hyperthread we are on */
if (smp_num_siblings == 2) {
unsigned int ebx, apicid;
ebx = cpuid_ebx(1);
apicid = (ebx >> 24) & 0xff;
ht_num = apicid & 1;
} else
#endif
ht_num = 0;
/* performance counters are shared resources
* assign each hyperthread its own set
* (re-use the ESCR0 register, seems safe
* and keeps the cccr_val the same)
*/
if (!ht_num) {
/* logical cpu 0 */
perfctr_msr = MSR_P4_IQ_PERFCTR0;
evntsel_msr = MSR_P4_CRU_ESCR0;
cccr_msr = MSR_P4_IQ_CCCR0;
cccr_val = P4_CCCR_OVF_PMI0 | P4_CCCR_ESCR_SELECT(4);
} else {
/* logical cpu 1 */
perfctr_msr = MSR_P4_IQ_PERFCTR1;
evntsel_msr = MSR_P4_CRU_ESCR0;
cccr_msr = MSR_P4_IQ_CCCR1;
cccr_val = P4_CCCR_OVF_PMI1 | P4_CCCR_ESCR_SELECT(4);
}
if (!__reserve_perfctr_nmi(-1, perfctr_msr))
goto fail;
if (!__reserve_evntsel_nmi(-1, evntsel_msr))
goto fail1;
evntsel = P4_ESCR_EVENT_SELECT(0x3F)
| P4_ESCR_OS
| P4_ESCR_USR;
cccr_val |= P4_CCCR_THRESHOLD(15)
| P4_CCCR_COMPLEMENT
| P4_CCCR_COMPARE
| P4_CCCR_REQUIRED;
wrmsr(evntsel_msr, evntsel, 0);
wrmsr(cccr_msr, cccr_val, 0);
write_watchdog_counter(perfctr_msr, "P4_IQ_COUNTER0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
cccr_val |= P4_CCCR_ENABLE;
wrmsr(cccr_msr, cccr_val, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = cccr_msr;
wd->check_bit = 1ULL<<39;
return 1;
fail1:
__release_perfctr_nmi(-1, perfctr_msr);
fail:
return 0;
}
static void stop_p4_watchdog(void)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
wrmsr(wd->cccr_msr, 0, 0);
wrmsr(wd->evntsel_msr, 0, 0);
__release_evntsel_nmi(-1, wd->evntsel_msr);
__release_perfctr_nmi(-1, wd->perfctr_msr);
}
#define ARCH_PERFMON_NMI_EVENT_SEL ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL
#define ARCH_PERFMON_NMI_EVENT_UMASK ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK
static int setup_intel_arch_watchdog(void)
{
unsigned int ebx;
union cpuid10_eax eax;
unsigned int unused;
unsigned int perfctr_msr, evntsel_msr;
unsigned int evntsel;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
/*
* Check whether the Architectural PerfMon supports
* Unhalted Core Cycles Event or not.
* NOTE: Corresponding bit = 0 in ebx indicates event present.
*/
cpuid(10, &(eax.full), &ebx, &unused, &unused);
if ((eax.split.mask_length < (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX+1)) ||
(ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT))
goto fail;
perfctr_msr = MSR_ARCH_PERFMON_PERFCTR1;
evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL1;
if (!__reserve_perfctr_nmi(-1, perfctr_msr))
goto fail;
if (!__reserve_evntsel_nmi(-1, evntsel_msr))
goto fail1;
wrmsrl(perfctr_msr, 0UL);
evntsel = ARCH_PERFMON_EVENTSEL_INT
| ARCH_PERFMON_EVENTSEL_OS
| ARCH_PERFMON_EVENTSEL_USR
| ARCH_PERFMON_NMI_EVENT_SEL
| ARCH_PERFMON_NMI_EVENT_UMASK;
/* setup the timer */
wrmsr(evntsel_msr, evntsel, 0);
nmi_hz = adjust_for_32bit_ctr(nmi_hz);
write_watchdog_counter32(perfctr_msr, "INTEL_ARCH_PERFCTR0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= ARCH_PERFMON_EVENTSEL0_ENABLE;
wrmsr(evntsel_msr, evntsel, 0);
wd->perfctr_msr = perfctr_msr;
wd->evntsel_msr = evntsel_msr;
wd->cccr_msr = 0; //unused
wd->check_bit = 1ULL << (eax.split.bit_width - 1);
return 1;
fail1:
__release_perfctr_nmi(-1, perfctr_msr);
fail:
return 0;
}
static void stop_intel_arch_watchdog(void)
{
unsigned int ebx;
union cpuid10_eax eax;
unsigned int unused;
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
/*
* Check whether the Architectural PerfMon supports
* Unhalted Core Cycles Event or not.
* NOTE: Corresponding bit = 0 in ebx indicates event present.
*/
cpuid(10, &(eax.full), &ebx, &unused, &unused);
if ((eax.split.mask_length < (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX+1)) ||
(ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT))
return;
wrmsr(wd->evntsel_msr, 0, 0);
__release_evntsel_nmi(-1, wd->evntsel_msr);
__release_perfctr_nmi(-1, wd->perfctr_msr);
if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
on_each_cpu(__acpi_nmi_disable, NULL, 0, 1);
}
void setup_apic_nmi_watchdog (void *unused)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
/* only support LOCAL and IO APICs for now */
if ((nmi_watchdog != NMI_LOCAL_APIC) &&
(nmi_watchdog != NMI_IO_APIC))
return;
if (wd->enabled == 1)
return;
if (__get_cpu_var(wd_enabled))
return;
/* cheap hack to support suspend/resume */
/* if cpu0 is not active neither should the other cpus */
if ((smp_processor_id() != 0) && (atomic_read(&nmi_active) <= 0))
return;
if (nmi_watchdog == NMI_LOCAL_APIC) {
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15 &&
boot_cpu_data.x86 != 16)
return;
if (!setup_k7_watchdog())
return;
break;
case X86_VENDOR_INTEL:
if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
if (!setup_intel_arch_watchdog())
return;
break;
}
switch (boot_cpu_data.x86) {
case 6:
if (boot_cpu_data.x86_model > 0xd)
return;
if (!setup_p6_watchdog())
return;
break;
case 15:
if (boot_cpu_data.x86_model > 0x4)
return;
if (!setup_p4_watchdog())
return;
break;
default:
return;
}
break;
default:
switch (nmi_watchdog) {
case NMI_LOCAL_APIC:
__get_cpu_var(wd_enabled) = 1; /* enable it before to avoid race with handler */
if (lapic_watchdog_init(nmi_hz) < 0) {
__get_cpu_var(wd_enabled) = 0;
return;
}
/* FALL THROUGH */
case NMI_IO_APIC:
__get_cpu_var(wd_enabled) = 1;
atomic_inc(&nmi_active);
}
wd->enabled = 1;
atomic_inc(&nmi_active);
}
void stop_apic_nmi_watchdog(void *unused)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
/* only support LOCAL and IO APICs for now */
if ((nmi_watchdog != NMI_LOCAL_APIC) &&
(nmi_watchdog != NMI_IO_APIC))
return;
if (wd->enabled == 0)
if (__get_cpu_var(wd_enabled) == 0)
return;
if (nmi_watchdog == NMI_LOCAL_APIC) {
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
stop_k7_watchdog();
break;
case X86_VENDOR_INTEL:
if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
stop_intel_arch_watchdog();
break;
}
switch (boot_cpu_data.x86) {
case 6:
if (boot_cpu_data.x86_model > 0xd)
break;
stop_p6_watchdog();
break;
case 15:
if (boot_cpu_data.x86_model > 0x4)
break;
stop_p4_watchdog();
break;
}
break;
default:
return;
}
}
wd->enabled = 0;
if (nmi_watchdog == NMI_LOCAL_APIC)
lapic_watchdog_stop();
__get_cpu_var(wd_enabled) = 0;
atomic_dec(&nmi_active);
}
@ -1008,8 +328,6 @@ __kprobes int nmi_watchdog_tick(struct pt_regs * regs, unsigned reason)
unsigned int sum;
int touched = 0;
int cpu = smp_processor_id();
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
u64 dummy;
int rc=0;
/* check for other users first */
@ -1052,53 +370,20 @@ __kprobes int nmi_watchdog_tick(struct pt_regs * regs, unsigned reason)
alert_counter[cpu] = 0;
}
/* see if the nmi watchdog went off */
if (wd->enabled) {
if (nmi_watchdog == NMI_LOCAL_APIC) {
rdmsrl(wd->perfctr_msr, dummy);
if (dummy & wd->check_bit){
/* this wasn't a watchdog timer interrupt */
goto done;
}
/* only Intel P4 uses the cccr msr */
if (wd->cccr_msr != 0) {
/*
* P4 quirks:
* - An overflown perfctr will assert its interrupt
* until the OVF flag in its CCCR is cleared.
* - LVTPC is masked on interrupt and must be
* unmasked by the LVTPC handler.
*/
rdmsrl(wd->cccr_msr, dummy);
dummy &= ~P4_CCCR_OVF;
wrmsrl(wd->cccr_msr, dummy);
apic_write(APIC_LVTPC, APIC_DM_NMI);
/* start the cycle over again */
write_watchdog_counter(wd->perfctr_msr, NULL);
}
else if (wd->perfctr_msr == MSR_P6_PERFCTR0 ||
wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1) {
/* P6 based Pentium M need to re-unmask
* the apic vector but it doesn't hurt
* other P6 variant.
* ArchPerfom/Core Duo also needs this */
apic_write(APIC_LVTPC, APIC_DM_NMI);
/* P6/ARCH_PERFMON has 32 bit counter write */
write_watchdog_counter32(wd->perfctr_msr, NULL);
} else {
/* start the cycle over again */
write_watchdog_counter(wd->perfctr_msr, NULL);
}
rc = 1;
} else if (nmi_watchdog == NMI_IO_APIC) {
/* don't know how to accurately check for this.
* just assume it was a watchdog timer interrupt
* This matches the old behaviour.
*/
rc = 1;
}
if (!__get_cpu_var(wd_enabled))
return rc;
switch (nmi_watchdog) {
case NMI_LOCAL_APIC:
rc |= lapic_wd_event(nmi_hz);
break;
case NMI_IO_APIC:
/* don't know how to accurately check for this.
* just assume it was a watchdog timer interrupt
* This matches the old behaviour.
*/
rc = 1;
break;
}
done:
return rc;
}
@ -1143,7 +428,7 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
}
if (nmi_watchdog == NMI_DEFAULT) {
if (nmi_known_cpu() > 0)
if (lapic_watchdog_ok())
nmi_watchdog = NMI_LOCAL_APIC;
else
nmi_watchdog = NMI_IO_APIC;
@ -1179,11 +464,3 @@ void __trigger_all_cpu_backtrace(void)
EXPORT_SYMBOL(nmi_active);
EXPORT_SYMBOL(nmi_watchdog);
EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi);
EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi_bit);
EXPORT_SYMBOL(reserve_perfctr_nmi);
EXPORT_SYMBOL(release_perfctr_nmi);
EXPORT_SYMBOL(reserve_evntsel_nmi);
EXPORT_SYMBOL(release_evntsel_nmi);
EXPORT_SYMBOL(disable_timer_nmi_watchdog);
EXPORT_SYMBOL(enable_timer_nmi_watchdog);

View file

@ -50,4 +50,12 @@ void __trigger_all_cpu_backtrace(void);
#endif
void lapic_watchdog_stop(void);
int lapic_watchdog_init(unsigned nmi_hz);
int lapic_wd_event(unsigned nmi_hz);
unsigned lapic_adjust_nmi_hz(unsigned hz);
int lapic_watchdog_ok(void);
void disable_lapic_nmi_watchdog(void);
void enable_lapic_nmi_watchdog(void);
#endif /* ASM_NMI_H */