1 files changed, 121 insertions, 5 deletions

diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index 6e5085d5d2f6..7b9a053effa3 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 */