1 files changed, 125 insertions, 5 deletions

diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 1b76d1574529..4d6fb047952e 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -26,6 +26,7 @@
 #include <asm/proto.h>
 #include <asm/kdebug.h>
 #include <asm/mce.h>
+#include <asm/intel_arch_perfmon.h>
 
 /* perfctr_nmi_owner tracks the ownership of the perfctr registers:
  * evtsel_nmi_owner tracks the ownership of the event selection
@@ -73,7 +74,10 @@ 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:
-                return (msr - MSR_P4_BPU_PERFCTR0);
+                if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
+                        return (msr - MSR_ARCH_PERFMON_PERFCTR0);
+                else
+                        return (msr - MSR_P4_BPU_PERFCTR0);
         }
         return 0;
 }
@@ -86,7 +90,10 @@ 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:
-                return (msr - MSR_P4_BSU_ESCR0);
+                if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
+                        return (msr - MSR_ARCH_PERFMON_EVENTSEL0);
+                else
+                        return (msr - MSR_P4_BSU_ESCR0);
         }
         return 0;
 }
@@ -160,7 +167,10 @@ static __cpuinit inline int nmi_known_cpu(void)
         case X86_VENDOR_AMD:
                 return boot_cpu_data.x86 == 15;
         case X86_VENDOR_INTEL:
-                return boot_cpu_data.x86 == 15;
+                if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
+                        return 1;
+                else
+                        return (boot_cpu_data.x86 == 15);
         }
         return 0;
 }
@@ -246,8 +256,22 @@ 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) {
+                        nmi_hz = ((u64)cpu_khz * 1000) / 0x7fffffffUL + 1;
+                }
+        }
 
         kfree(counts);
         return 0;
@@ -563,6 +587,87 @@ 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);
+        wrmsrl(perfctr_msr, -((u64)cpu_khz * 1000 / 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->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);
@@ -589,6 +694,11 @@ 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;
+                        }
                         if (!setup_p4_watchdog())
                                 return;
                         break;
@@ -620,6 +730,10 @@ 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;
+                        }
                         stop_p4_watchdog();
                         break;
                 default:
@@ -724,7 +838,13 @@ int __kprobes nmi_watchdog_tick(struct pt_regs * regs, unsigned reason)
                                 dummy &= ~P4_CCCR_OVF;
                                 wrmsrl(wd->cccr_msr, dummy);
                                 apic_write(APIC_LVTPC, APIC_DM_NMI);
-                        }
+                        } else if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0) {
+                                /*
+                                 * ArchPerfom/Core Duo needs to re-unmask
+                                 * the apic vector
+                                 */
+                                apic_write(APIC_LVTPC, APIC_DM_NMI);
+                        }
                         /* start the cycle over again */
                         wrmsrl(wd->perfctr_msr, -((u64)cpu_khz * 1000 / nmi_hz));
                         rc = 1;