Merge branch 'stable/generic' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

[pandora-kernel.git] / arch / x86 / kernel / cpu / perf_event.c

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index ba85814..0492101 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -330,9 +330,6 @@ static bool reserve_pmc_hardware(void)
 {
        int i;
 
-       if (nmi_watchdog == NMI_LOCAL_APIC)
-               disable_lapic_nmi_watchdog();
-
        for (i = 0; i < x86_pmu.num_counters; i++) {
                if (!reserve_perfctr_nmi(x86_pmu.perfctr + i))
                        goto perfctr_fail;
@@ -355,9 +352,6 @@ perfctr_fail:
        for (i--; i >= 0; i--)
                release_perfctr_nmi(x86_pmu.perfctr + i);
 
-       if (nmi_watchdog == NMI_LOCAL_APIC)
-               enable_lapic_nmi_watchdog();
-
        return false;
 }
 
@@ -369,9 +363,6 @@ static void release_pmc_hardware(void)
                release_perfctr_nmi(x86_pmu.perfctr + i);
                release_evntsel_nmi(x86_pmu.eventsel + i);
        }
-
-       if (nmi_watchdog == NMI_LOCAL_APIC)
-               enable_lapic_nmi_watchdog();
 }
 
 #else
@@ -384,15 +375,53 @@ static void release_pmc_hardware(void) {}
 static bool check_hw_exists(void)
 {
        u64 val, val_new = 0;
-       int ret = 0;
+       int i, reg, ret = 0;
+
+       /*
+        * Check to see if the BIOS enabled any of the counters, if so
+        * complain and bail.
+        */
+       for (i = 0; i < x86_pmu.num_counters; i++) {
+               reg = x86_pmu.eventsel + i;
+               ret = rdmsrl_safe(reg, &val);
+               if (ret)
+                       goto msr_fail;
+               if (val & ARCH_PERFMON_EVENTSEL_ENABLE)
+                       goto bios_fail;
+       }
 
+       if (x86_pmu.num_counters_fixed) {
+               reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
+               ret = rdmsrl_safe(reg, &val);
+               if (ret)
+                       goto msr_fail;
+               for (i = 0; i < x86_pmu.num_counters_fixed; i++) {
+                       if (val & (0x03 << i*4))
+                               goto bios_fail;
+               }
+       }
+
+       /*
+        * Now write a value and read it back to see if it matches,
+        * this is needed to detect certain hardware emulators (qemu/kvm)
+        * that don't trap on the MSR access and always return 0s.
+        */
        val = 0xabcdUL;
-       ret |= checking_wrmsrl(x86_pmu.perfctr, val);
+       ret = checking_wrmsrl(x86_pmu.perfctr, val);
        ret |= rdmsrl_safe(x86_pmu.perfctr, &val_new);
        if (ret || val != val_new)
-               return false;
+               goto msr_fail;
 
        return true;
+
+bios_fail:
+       printk(KERN_CONT "Broken BIOS detected, using software events only.\n");
+       printk(KERN_ERR FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", reg, val);
+       return false;
+
+msr_fail:
+       printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n");
+       return false;
 }
 
 static void reserve_ds_buffers(void);
@@ -451,7 +480,7 @@ static int x86_setup_perfctr(struct perf_event *event)
        struct hw_perf_event *hwc = &event->hw;
        u64 config;
 
-       if (!hwc->sample_period) {
+       if (!is_sampling_event(event)) {
                hwc->sample_period = x86_pmu.max_period;
                hwc->last_period = hwc->sample_period;
                local64_set(&hwc->period_left, hwc->sample_period);
@@ -1361,7 +1390,7 @@ static void __init pmu_check_apic(void)
        pr_info("no hardware sampling interrupt available.\n");
 }
 
-void __init init_hw_perf_events(void)
+int __init init_hw_perf_events(void)
 {
        struct event_constraint *c;
        int err;
@@ -1376,20 +1405,18 @@ void __init init_hw_perf_events(void)
                err = amd_pmu_init();
                break;
        default:
-               return;
+               return 0;
        }
        if (err != 0) {
                pr_cont("no PMU driver, software events only.\n");
-               return;
+               return 0;
        }
 
        pmu_check_apic();
 
        /* sanity check that the hardware exists or is emulated */
-       if (!check_hw_exists()) {
-               pr_cont("Broken PMU hardware detected, software events only.\n");
-               return;
-       }
+       if (!check_hw_exists())
+               return 0;
 
        pr_cont("%s PMU driver.\n", x86_pmu.name);
 
@@ -1437,9 +1464,12 @@ void __init init_hw_perf_events(void)
        pr_info("... fixed-purpose events:   %d\n",     x86_pmu.num_counters_fixed);
        pr_info("... event mask:             %016Lx\n", x86_pmu.intel_ctrl);
 
-       perf_pmu_register(&pmu);
+       perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
        perf_cpu_notifier(x86_pmu_notifier);
+
+       return 0;
 }
+early_initcall(init_hw_perf_events);
 
 static inline void x86_pmu_read(struct perf_event *event)
 {
@@ -1681,7 +1711,7 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
 
        perf_callchain_store(entry, regs->ip);
 
-       dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry);
+       dump_trace(NULL, regs, NULL, &backtrace_ops, entry);
 }
 
 #ifdef CONFIG_COMPAT