aboutsummaryrefslogtreecommitdiff
path: root/arch/i386/kernel/nmi.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/i386/kernel/nmi.c')
-rw-r--r--arch/i386/kernel/nmi.c126
1 files changed, 121 insertions, 5 deletions
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index 6e5085d5d2f..7b9a053effa 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -26,6 +26,7 @@
#include <asm/smp.h>
#include <asm/nmi.h>
#include <asm/kdebug.h>
+#include <asm/intel_arch_perfmon.h>
#include "mach_traps.h"
@@ -77,6 +78,9 @@ static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
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);
@@ -95,6 +99,9 @@ static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr)
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);
@@ -174,7 +181,10 @@ static __cpuinit inline int nmi_known_cpu(void)
case X86_VENDOR_AMD:
return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6));
case X86_VENDOR_INTEL:
- return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6));
+ 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;
}
@@ -261,8 +271,24 @@ static int __init check_nmi_watchdog(void)
/* now that we know it works we can reduce NMI frequency to
something more reasonable; makes a difference in some configs */
- if (nmi_watchdog == NMI_LOCAL_APIC)
+ if (nmi_watchdog == NMI_LOCAL_APIC) {
+ struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
+
nmi_hz = 1;
+ /*
+ * On Intel CPUs with 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
+ */
+ if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0 &&
+ ((u64)cpu_khz * 1000) > 0x7fffffffULL) {
+ u64 count = (u64)cpu_khz * 1000;
+ do_div(count, 0x7fffffffUL);
+ nmi_hz = count + 1;
+ }
+ }
kfree(prev_nmi_count);
return 0;
@@ -637,6 +663,85 @@ static void stop_p4_watchdog(void)
release_perfctr_nmi(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_PERFCTR0;
+ evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL0;
+
+ if (!reserve_perfctr_nmi(perfctr_msr))
+ goto fail;
+
+ if (!reserve_evntsel_nmi(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);
+ write_watchdog_counter(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(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(wd->evntsel_msr);
+ release_perfctr_nmi(wd->perfctr_msr);
+}
+
void setup_apic_nmi_watchdog (void *unused)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
@@ -663,6 +768,11 @@ void setup_apic_nmi_watchdog (void *unused)
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)
@@ -708,6 +818,10 @@ void stop_apic_nmi_watchdog(void *unused)
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)
@@ -831,10 +945,12 @@ int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason)
wrmsrl(wd->cccr_msr, dummy);
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
- else if (wd->perfctr_msr == MSR_P6_PERFCTR0) {
- /* Only P6 based Pentium M need to re-unmask
+ else if (wd->perfctr_msr == MSR_P6_PERFCTR0 ||
+ wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0) {
+ /* P6 based Pentium M need to re-unmask
* the apic vector but it doesn't hurt
- * other P6 variant */
+ * other P6 variant.
+ * ArchPerfom/Core Duo also needs this */
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
/* start the cycle over again */