forked from luck/tmp_suning_uos_patched
405e494d91
Hello, This patch against 2.6.20-git14 makes the NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0 on processors supporting Intel architectural perfmon, such as Intel Core 2. Although all PMU events can work on both counters, the Precise Event-Based Sampling (PEBS) requires that the event be in PERFCTR0 to work correctly (see section 18.14.4.1 in the IA32 SDM Vol 3b). This versions has 3 chunks compared to previous where we had missed on check. Changelog: - make the x86-64 NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0 on processors supporting the Intel architectural perfmon (e.g. Core 2 Duo). This allows PEBS to work when the NMI watchdog is active. signed-off-by: stephane eranian <eranian@hpl.hp.com> Signed-off-by: Andi Kleen <ak@suse.de>
1079 lines
26 KiB
C
1079 lines
26 KiB
C
/*
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* linux/arch/x86_64/nmi.c
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*
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* NMI watchdog support on APIC systems
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*
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* Started by Ingo Molnar <mingo@redhat.com>
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*
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* Fixes:
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* Mikael Pettersson : AMD K7 support for local APIC NMI watchdog.
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* Mikael Pettersson : Power Management for local APIC NMI watchdog.
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* Pavel Machek and
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* Mikael Pettersson : PM converted to driver model. Disable/enable API.
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*/
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#include <linux/nmi.h>
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#include <linux/mm.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/sysdev.h>
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#include <linux/sysctl.h>
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#include <linux/kprobes.h>
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#include <linux/cpumask.h>
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#include <asm/smp.h>
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#include <asm/nmi.h>
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#include <asm/proto.h>
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#include <asm/kdebug.h>
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#include <asm/mce.h>
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#include <asm/intel_arch_perfmon.h>
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int unknown_nmi_panic;
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int nmi_watchdog_enabled;
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int panic_on_unrecovered_nmi;
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/* perfctr_nmi_owner tracks the ownership of the perfctr registers:
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* evtsel_nmi_owner tracks the ownership of the event selection
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* - different performance counters/ event selection may be reserved for
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* different subsystems this reservation system just tries to coordinate
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* things a little
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*/
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/* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's
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* offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now)
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*/
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#define NMI_MAX_COUNTER_BITS 66
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#define NMI_MAX_COUNTER_LONGS BITS_TO_LONGS(NMI_MAX_COUNTER_BITS)
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static DEFINE_PER_CPU(unsigned, perfctr_nmi_owner[NMI_MAX_COUNTER_LONGS]);
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static DEFINE_PER_CPU(unsigned, evntsel_nmi_owner[NMI_MAX_COUNTER_LONGS]);
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static cpumask_t backtrace_mask = CPU_MASK_NONE;
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/* nmi_active:
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* >0: the lapic NMI watchdog is active, but can be disabled
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* <0: the lapic NMI watchdog has not been set up, and cannot
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* be enabled
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* 0: the lapic NMI watchdog is disabled, but can be enabled
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*/
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atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */
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int panic_on_timeout;
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unsigned int nmi_watchdog = NMI_DEFAULT;
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static unsigned int nmi_hz = HZ;
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struct nmi_watchdog_ctlblk {
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int enabled;
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u64 check_bit;
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unsigned int cccr_msr;
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unsigned int perfctr_msr; /* the MSR to reset in NMI handler */
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unsigned int evntsel_msr; /* the MSR to select the events to handle */
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};
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static DEFINE_PER_CPU(struct nmi_watchdog_ctlblk, nmi_watchdog_ctlblk);
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/* local prototypes */
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static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu);
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/* converts an msr to an appropriate reservation bit */
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static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
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{
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/* returns the bit offset of the performance counter register */
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switch (boot_cpu_data.x86_vendor) {
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case X86_VENDOR_AMD:
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return (msr - MSR_K7_PERFCTR0);
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case X86_VENDOR_INTEL:
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if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
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return (msr - MSR_ARCH_PERFMON_PERFCTR0);
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else
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return (msr - MSR_P4_BPU_PERFCTR0);
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}
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return 0;
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}
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/* converts an msr to an appropriate reservation bit */
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static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr)
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{
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/* returns the bit offset of the event selection register */
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switch (boot_cpu_data.x86_vendor) {
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case X86_VENDOR_AMD:
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return (msr - MSR_K7_EVNTSEL0);
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case X86_VENDOR_INTEL:
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if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
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return (msr - MSR_ARCH_PERFMON_EVENTSEL0);
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else
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return (msr - MSR_P4_BSU_ESCR0);
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}
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return 0;
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}
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/* checks for a bit availability (hack for oprofile) */
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int avail_to_resrv_perfctr_nmi_bit(unsigned int counter)
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{
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int cpu;
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BUG_ON(counter > NMI_MAX_COUNTER_BITS);
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for_each_possible_cpu (cpu) {
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if (test_bit(counter, &per_cpu(perfctr_nmi_owner, cpu)))
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return 0;
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}
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return 1;
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}
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/* checks the an msr for availability */
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int avail_to_resrv_perfctr_nmi(unsigned int msr)
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{
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unsigned int counter;
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int cpu;
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counter = nmi_perfctr_msr_to_bit(msr);
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BUG_ON(counter > NMI_MAX_COUNTER_BITS);
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for_each_possible_cpu (cpu) {
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if (test_bit(counter, &per_cpu(perfctr_nmi_owner, cpu)))
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return 0;
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}
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return 1;
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}
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static int __reserve_perfctr_nmi(int cpu, unsigned int msr)
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{
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unsigned int counter;
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if (cpu < 0)
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cpu = smp_processor_id();
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counter = nmi_perfctr_msr_to_bit(msr);
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BUG_ON(counter > NMI_MAX_COUNTER_BITS);
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if (!test_and_set_bit(counter, &per_cpu(perfctr_nmi_owner, cpu)))
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return 1;
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return 0;
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}
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static void __release_perfctr_nmi(int cpu, unsigned int msr)
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{
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unsigned int counter;
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if (cpu < 0)
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cpu = smp_processor_id();
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counter = nmi_perfctr_msr_to_bit(msr);
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BUG_ON(counter > NMI_MAX_COUNTER_BITS);
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clear_bit(counter, &per_cpu(perfctr_nmi_owner, cpu));
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}
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int reserve_perfctr_nmi(unsigned int msr)
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{
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int cpu, i;
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for_each_possible_cpu (cpu) {
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if (!__reserve_perfctr_nmi(cpu, msr)) {
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for_each_possible_cpu (i) {
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if (i >= cpu)
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break;
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__release_perfctr_nmi(i, msr);
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}
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return 0;
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}
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}
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return 1;
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}
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void release_perfctr_nmi(unsigned int msr)
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{
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int cpu;
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for_each_possible_cpu (cpu)
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__release_perfctr_nmi(cpu, msr);
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}
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int __reserve_evntsel_nmi(int cpu, unsigned int msr)
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{
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unsigned int counter;
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if (cpu < 0)
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cpu = smp_processor_id();
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counter = nmi_evntsel_msr_to_bit(msr);
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BUG_ON(counter > NMI_MAX_COUNTER_BITS);
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if (!test_and_set_bit(counter, &per_cpu(evntsel_nmi_owner, cpu)[0]))
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return 1;
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return 0;
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}
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static void __release_evntsel_nmi(int cpu, unsigned int msr)
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{
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unsigned int counter;
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if (cpu < 0)
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cpu = smp_processor_id();
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counter = nmi_evntsel_msr_to_bit(msr);
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BUG_ON(counter > NMI_MAX_COUNTER_BITS);
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clear_bit(counter, &per_cpu(evntsel_nmi_owner, cpu)[0]);
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}
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int reserve_evntsel_nmi(unsigned int msr)
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{
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int cpu, i;
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for_each_possible_cpu (cpu) {
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if (!__reserve_evntsel_nmi(cpu, msr)) {
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for_each_possible_cpu (i) {
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if (i >= cpu)
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break;
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__release_evntsel_nmi(i, msr);
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}
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return 0;
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}
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}
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return 1;
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}
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void release_evntsel_nmi(unsigned int msr)
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{
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int cpu;
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for_each_possible_cpu (cpu) {
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__release_evntsel_nmi(cpu, msr);
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}
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}
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static __cpuinit inline int nmi_known_cpu(void)
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{
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switch (boot_cpu_data.x86_vendor) {
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case X86_VENDOR_AMD:
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return boot_cpu_data.x86 == 15 || boot_cpu_data.x86 == 16;
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case X86_VENDOR_INTEL:
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if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
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return 1;
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else
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return (boot_cpu_data.x86 == 15);
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}
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return 0;
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}
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/* Run after command line and cpu_init init, but before all other checks */
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void nmi_watchdog_default(void)
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{
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if (nmi_watchdog != NMI_DEFAULT)
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return;
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nmi_watchdog = NMI_NONE;
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}
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static int endflag __initdata = 0;
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#ifdef CONFIG_SMP
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/* The performance counters used by NMI_LOCAL_APIC don't trigger when
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* the CPU is idle. To make sure the NMI watchdog really ticks on all
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* CPUs during the test make them busy.
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*/
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static __init void nmi_cpu_busy(void *data)
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{
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local_irq_enable_in_hardirq();
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/* Intentionally don't use cpu_relax here. This is
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to make sure that the performance counter really ticks,
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even if there is a simulator or similar that catches the
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pause instruction. On a real HT machine this is fine because
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all other CPUs are busy with "useless" delay loops and don't
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care if they get somewhat less cycles. */
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while (endflag == 0)
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mb();
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}
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#endif
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static unsigned int adjust_for_32bit_ctr(unsigned int hz)
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{
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unsigned int retval = hz;
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/*
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* On Intel CPUs with ARCH_PERFMON only 32 bits in the counter
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* are writable, with higher bits sign extending from bit 31.
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* So, we can only program the counter with 31 bit values and
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* 32nd bit should be 1, for 33.. to be 1.
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* Find the appropriate nmi_hz
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*/
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if ((((u64)cpu_khz * 1000) / retval) > 0x7fffffffULL) {
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retval = ((u64)cpu_khz * 1000) / 0x7fffffffUL + 1;
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}
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return retval;
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}
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int __init check_nmi_watchdog (void)
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{
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int *counts;
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int cpu;
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if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DEFAULT))
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return 0;
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if (!atomic_read(&nmi_active))
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return 0;
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counts = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
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if (!counts)
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return -1;
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printk(KERN_INFO "testing NMI watchdog ... ");
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#ifdef CONFIG_SMP
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if (nmi_watchdog == NMI_LOCAL_APIC)
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smp_call_function(nmi_cpu_busy, (void *)&endflag, 0, 0);
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#endif
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for (cpu = 0; cpu < NR_CPUS; cpu++)
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counts[cpu] = cpu_pda(cpu)->__nmi_count;
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local_irq_enable();
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mdelay((20*1000)/nmi_hz); // wait 20 ticks
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for_each_online_cpu(cpu) {
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if (!per_cpu(nmi_watchdog_ctlblk, cpu).enabled)
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continue;
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if (cpu_pda(cpu)->__nmi_count - counts[cpu] <= 5) {
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printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n",
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cpu,
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counts[cpu],
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cpu_pda(cpu)->__nmi_count);
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per_cpu(nmi_watchdog_ctlblk, cpu).enabled = 0;
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atomic_dec(&nmi_active);
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}
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}
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if (!atomic_read(&nmi_active)) {
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kfree(counts);
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atomic_set(&nmi_active, -1);
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endflag = 1;
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return -1;
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}
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endflag = 1;
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printk("OK.\n");
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/* now that we know it works we can reduce NMI frequency to
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something more reasonable; makes a difference in some configs */
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if (nmi_watchdog == NMI_LOCAL_APIC) {
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struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
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nmi_hz = 1;
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if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1)
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nmi_hz = adjust_for_32bit_ctr(nmi_hz);
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}
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kfree(counts);
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return 0;
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}
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int __init setup_nmi_watchdog(char *str)
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{
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int nmi;
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if (!strncmp(str,"panic",5)) {
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panic_on_timeout = 1;
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str = strchr(str, ',');
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if (!str)
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return 1;
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++str;
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}
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get_option(&str, &nmi);
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if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
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return 0;
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nmi_watchdog = nmi;
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return 1;
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}
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__setup("nmi_watchdog=", setup_nmi_watchdog);
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static void disable_lapic_nmi_watchdog(void)
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{
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BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
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if (atomic_read(&nmi_active) <= 0)
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return;
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on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1);
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BUG_ON(atomic_read(&nmi_active) != 0);
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}
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static void enable_lapic_nmi_watchdog(void)
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{
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BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
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/* are we already enabled */
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if (atomic_read(&nmi_active) != 0)
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return;
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/* are we lapic aware */
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if (nmi_known_cpu() <= 0)
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return;
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on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1);
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touch_nmi_watchdog();
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}
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void disable_timer_nmi_watchdog(void)
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{
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BUG_ON(nmi_watchdog != NMI_IO_APIC);
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if (atomic_read(&nmi_active) <= 0)
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return;
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disable_irq(0);
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on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1);
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BUG_ON(atomic_read(&nmi_active) != 0);
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}
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void enable_timer_nmi_watchdog(void)
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{
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BUG_ON(nmi_watchdog != NMI_IO_APIC);
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if (atomic_read(&nmi_active) == 0) {
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touch_nmi_watchdog();
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on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1);
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enable_irq(0);
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}
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}
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static void __acpi_nmi_disable(void *__unused)
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{
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apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
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}
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/*
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* Disable timer based NMIs on all CPUs:
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*/
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void acpi_nmi_disable(void)
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{
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if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
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on_each_cpu(__acpi_nmi_disable, NULL, 0, 1);
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}
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static void __acpi_nmi_enable(void *__unused)
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{
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apic_write(APIC_LVT0, APIC_DM_NMI);
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}
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/*
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* Enable timer based NMIs on all CPUs:
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*/
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void acpi_nmi_enable(void)
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{
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if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
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on_each_cpu(__acpi_nmi_enable, NULL, 0, 1);
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}
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#ifdef CONFIG_PM
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static int nmi_pm_active; /* nmi_active before suspend */
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static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state)
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{
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/* only CPU0 goes here, other CPUs should be offline */
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nmi_pm_active = atomic_read(&nmi_active);
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stop_apic_nmi_watchdog(NULL);
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BUG_ON(atomic_read(&nmi_active) != 0);
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return 0;
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}
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static int lapic_nmi_resume(struct sys_device *dev)
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{
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/* only CPU0 goes here, other CPUs should be offline */
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if (nmi_pm_active > 0) {
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setup_apic_nmi_watchdog(NULL);
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touch_nmi_watchdog();
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}
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return 0;
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}
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static struct sysdev_class nmi_sysclass = {
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set_kset_name("lapic_nmi"),
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.resume = lapic_nmi_resume,
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.suspend = lapic_nmi_suspend,
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};
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static struct sys_device device_lapic_nmi = {
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.id = 0,
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.cls = &nmi_sysclass,
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};
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static int __init init_lapic_nmi_sysfs(void)
|
|
{
|
|
int error;
|
|
|
|
/* should really be a BUG_ON but b/c this is an
|
|
* init call, it just doesn't work. -dcz
|
|
*/
|
|
if (nmi_watchdog != NMI_LOCAL_APIC)
|
|
return 0;
|
|
|
|
if ( atomic_read(&nmi_active) < 0 )
|
|
return 0;
|
|
|
|
error = sysdev_class_register(&nmi_sysclass);
|
|
if (!error)
|
|
error = sysdev_register(&device_lapic_nmi);
|
|
return error;
|
|
}
|
|
/* must come after the local APIC's device_initcall() */
|
|
late_initcall(init_lapic_nmi_sysfs);
|
|
|
|
#endif /* CONFIG_PM */
|
|
|
|
/*
|
|
* Activate the NMI watchdog via the local APIC.
|
|
* Original code written by Keith Owens.
|
|
*/
|
|
|
|
/* 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;
|
|
|
|
/* Simulator may not support it */
|
|
if (checking_wrmsrl(evntsel_msr, 0UL))
|
|
goto fail2;
|
|
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);
|
|
wrmsrl(perfctr_msr, -((u64)cpu_khz * 1000 / 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
|
|
wd->check_bit = 1ULL<<63;
|
|
return 1;
|
|
fail2:
|
|
__release_evntsel_nmi(-1, evntsel_msr);
|
|
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);
|
|
}
|
|
|
|
/* 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);
|
|
wrmsrl(perfctr_msr, -((u64)cpu_khz * 1000 / 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;
|
|
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);
|
|
wrmsr(perfctr_msr, (u32)(-((u64)cpu_khz * 1000 / nmi_hz)), 0);
|
|
|
|
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);
|
|
}
|
|
|
|
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;
|
|
|
|
/* 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 (strstr(boot_cpu_data.x86_model_id, "Screwdriver"))
|
|
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;
|
|
}
|
|
if (!setup_p4_watchdog())
|
|
return;
|
|
break;
|
|
default:
|
|
return;
|
|
}
|
|
}
|
|
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)
|
|
return;
|
|
|
|
if (nmi_watchdog == NMI_LOCAL_APIC) {
|
|
switch (boot_cpu_data.x86_vendor) {
|
|
case X86_VENDOR_AMD:
|
|
if (strstr(boot_cpu_data.x86_model_id, "Screwdriver"))
|
|
return;
|
|
stop_k7_watchdog();
|
|
break;
|
|
case X86_VENDOR_INTEL:
|
|
if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
|
|
stop_intel_arch_watchdog();
|
|
break;
|
|
}
|
|
stop_p4_watchdog();
|
|
break;
|
|
default:
|
|
return;
|
|
}
|
|
}
|
|
wd->enabled = 0;
|
|
atomic_dec(&nmi_active);
|
|
}
|
|
|
|
/*
|
|
* the best way to detect whether a CPU has a 'hard lockup' problem
|
|
* is to check it's local APIC timer IRQ counts. If they are not
|
|
* changing then that CPU has some problem.
|
|
*
|
|
* as these watchdog NMI IRQs are generated on every CPU, we only
|
|
* have to check the current processor.
|
|
*/
|
|
|
|
static DEFINE_PER_CPU(unsigned, last_irq_sum);
|
|
static DEFINE_PER_CPU(local_t, alert_counter);
|
|
static DEFINE_PER_CPU(int, nmi_touch);
|
|
|
|
void touch_nmi_watchdog (void)
|
|
{
|
|
if (nmi_watchdog > 0) {
|
|
unsigned cpu;
|
|
|
|
/*
|
|
* Tell other CPUs to reset their alert counters. We cannot
|
|
* do it ourselves because the alert count increase is not
|
|
* atomic.
|
|
*/
|
|
for_each_present_cpu (cpu)
|
|
per_cpu(nmi_touch, cpu) = 1;
|
|
}
|
|
|
|
touch_softlockup_watchdog();
|
|
}
|
|
|
|
int __kprobes nmi_watchdog_tick(struct pt_regs * regs, unsigned reason)
|
|
{
|
|
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 */
|
|
if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
|
|
== NOTIFY_STOP) {
|
|
rc = 1;
|
|
touched = 1;
|
|
}
|
|
|
|
sum = read_pda(apic_timer_irqs);
|
|
if (__get_cpu_var(nmi_touch)) {
|
|
__get_cpu_var(nmi_touch) = 0;
|
|
touched = 1;
|
|
}
|
|
|
|
if (cpu_isset(cpu, backtrace_mask)) {
|
|
static DEFINE_SPINLOCK(lock); /* Serialise the printks */
|
|
|
|
spin_lock(&lock);
|
|
printk("NMI backtrace for cpu %d\n", cpu);
|
|
dump_stack();
|
|
spin_unlock(&lock);
|
|
cpu_clear(cpu, backtrace_mask);
|
|
}
|
|
|
|
#ifdef CONFIG_X86_MCE
|
|
/* Could check oops_in_progress here too, but it's safer
|
|
not too */
|
|
if (atomic_read(&mce_entry) > 0)
|
|
touched = 1;
|
|
#endif
|
|
/* if the apic timer isn't firing, this cpu isn't doing much */
|
|
if (!touched && __get_cpu_var(last_irq_sum) == sum) {
|
|
/*
|
|
* Ayiee, looks like this CPU is stuck ...
|
|
* wait a few IRQs (5 seconds) before doing the oops ...
|
|
*/
|
|
local_inc(&__get_cpu_var(alert_counter));
|
|
if (local_read(&__get_cpu_var(alert_counter)) == 5*nmi_hz)
|
|
die_nmi("NMI Watchdog detected LOCKUP on CPU %d\n", regs,
|
|
panic_on_timeout);
|
|
} else {
|
|
__get_cpu_var(last_irq_sum) = sum;
|
|
local_set(&__get_cpu_var(alert_counter), 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 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 */
|
|
wrmsrl(wd->perfctr_msr,
|
|
-((u64)cpu_khz * 1000 / nmi_hz));
|
|
} else if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1) {
|
|
/*
|
|
* ArchPerfom/Core Duo needs to re-unmask
|
|
* the apic vector
|
|
*/
|
|
apic_write(APIC_LVTPC, APIC_DM_NMI);
|
|
/* ARCH_PERFMON has 32 bit counter writes */
|
|
wrmsr(wd->perfctr_msr,
|
|
(u32)(-((u64)cpu_khz * 1000 / nmi_hz)), 0);
|
|
} else {
|
|
/* start the cycle over again */
|
|
wrmsrl(wd->perfctr_msr,
|
|
-((u64)cpu_khz * 1000 / nmi_hz));
|
|
}
|
|
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;
|
|
} else
|
|
printk(KERN_WARNING "Unknown enabled NMI hardware?!\n");
|
|
}
|
|
done:
|
|
return rc;
|
|
}
|
|
|
|
asmlinkage __kprobes void do_nmi(struct pt_regs * regs, long error_code)
|
|
{
|
|
nmi_enter();
|
|
add_pda(__nmi_count,1);
|
|
default_do_nmi(regs);
|
|
nmi_exit();
|
|
}
|
|
|
|
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)
|
|
{
|
|
unsigned char reason = get_nmi_reason();
|
|
char buf[64];
|
|
|
|
sprintf(buf, "NMI received for unknown reason %02x\n", reason);
|
|
die_nmi(buf, regs, 1); /* Always panic here */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* proc handler for /proc/sys/kernel/nmi
|
|
*/
|
|
int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
|
|
void __user *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
int old_state;
|
|
|
|
nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0;
|
|
old_state = nmi_watchdog_enabled;
|
|
proc_dointvec(table, write, file, buffer, length, ppos);
|
|
if (!!old_state == !!nmi_watchdog_enabled)
|
|
return 0;
|
|
|
|
if (atomic_read(&nmi_active) < 0) {
|
|
printk( KERN_WARNING "NMI watchdog is permanently disabled\n");
|
|
return -EIO;
|
|
}
|
|
|
|
/* if nmi_watchdog is not set yet, then set it */
|
|
nmi_watchdog_default();
|
|
|
|
if (nmi_watchdog == NMI_LOCAL_APIC) {
|
|
if (nmi_watchdog_enabled)
|
|
enable_lapic_nmi_watchdog();
|
|
else
|
|
disable_lapic_nmi_watchdog();
|
|
} else {
|
|
printk( KERN_WARNING
|
|
"NMI watchdog doesn't know what hardware to touch\n");
|
|
return -EIO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
void __trigger_all_cpu_backtrace(void)
|
|
{
|
|
int i;
|
|
|
|
backtrace_mask = cpu_online_map;
|
|
/* Wait for up to 10 seconds for all CPUs to do the backtrace */
|
|
for (i = 0; i < 10 * 1000; i++) {
|
|
if (cpus_empty(backtrace_mask))
|
|
break;
|
|
mdelay(1);
|
|
}
|
|
}
|
|
|
|
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);
|
|
EXPORT_SYMBOL(touch_nmi_watchdog);
|