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Date: Tue, 1 May 2007 05:58:00 +0200 (CEST)
From: Andi Kleen <ak@...e.de>
To: patches@...-64.org, linux-kernel@...r.kernel.org
Subject: [PATCH] [3/30] 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@...e.de>
---
arch/i386/kernel/cpu/Makefile | 2
arch/i386/kernel/cpu/perfctr-watchdog.c | 658 +++++++++++++++++++++++++
arch/i386/kernel/nmi.c | 829 ++------------------------------
include/asm-i386/nmi.h | 8
4 files changed, 721 insertions(+), 776 deletions(-)
Index: linux/arch/i386/kernel/nmi.c
===================================================================
--- linux.orig/arch/i386/kernel/nmi.c
+++ linux/arch/i386/kernel/nmi.c
@@ -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); /
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 *da
}
#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(voi
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(voi
/* 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(cha
__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(v
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 */
-/*
- * Activate the NMI watchdog via the local APIC.
- * Original code written by Keith Owens.
- */
-
-static void write_watchdog_counter(unsigned int perfctr_msr, const char *descr)
-{
- 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)
-{
- 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);
-}
-
-/* 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)
-{
- 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)
+static void __acpi_nmi_enable(void *__unused)
{
- 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;
+ apic_write_around(APIC_LVT0, APIC_DM_NMI);
}
-static void stop_p4_watchdog(void)
+/*
+ * Enable timer based NMIs on all CPUs:
+ */
+void acpi_nmi_enable(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);
+ if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
+ on_each_cpu(__acpi_nmi_enable, NULL, 0, 1);
}
-#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)
+static void __acpi_nmi_disable(void *__unused)
{
- 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;
+ apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
}
-static void stop_intel_arch_watchdog(void)
+/*
+ * Disable timer based NMIs on all CPUs:
+ */
+void acpi_nmi_disable(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 p
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 p
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 *t
}
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);
Index: linux/arch/i386/kernel/cpu/Makefile
===================================================================
--- linux.orig/arch/i386/kernel/cpu/Makefile
+++ linux/arch/i386/kernel/cpu/Makefile
@@ -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
Index: linux/arch/i386/kernel/cpu/perfctr-watchdog.c
===================================================================
--- /dev/null
+++ linux/arch/i386/kernel/cpu/perfctr-watchdog.c
@@ -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;
+}
Index: linux/include/asm-i386/nmi.h
===================================================================
--- linux.orig/include/asm-i386/nmi.h
+++ linux/include/asm-i386/nmi.h
@@ -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 */
-
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