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-rw-r--r--arch/x86_64/kernel/nmi.c46
1 files changed, 32 insertions, 14 deletions
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 9cb42ecb7f8..e59cda13416 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -214,6 +214,23 @@ static __init void nmi_cpu_busy(void *data)
}
#endif
+static unsigned int adjust_for_32bit_ctr(unsigned int hz)
+{
+ unsigned int retval = hz;
+
+ /*
+ * 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 ((((u64)cpu_khz * 1000) / retval) > 0x7fffffffULL) {
+ retval = ((u64)cpu_khz * 1000) / 0x7fffffffUL + 1;
+ }
+ return retval;
+}
+
int __init check_nmi_watchdog (void)
{
int *counts;
@@ -268,17 +285,8 @@ int __init check_nmi_watchdog (void)
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;
- }
+ if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0)
+ nmi_hz = adjust_for_32bit_ctr(nmi_hz);
}
kfree(counts);
@@ -634,7 +642,9 @@ static int setup_intel_arch_watchdog(void)
/* setup the timer */
wrmsr(evntsel_msr, evntsel, 0);
- wrmsrl(perfctr_msr, -((u64)cpu_khz * 1000 / nmi_hz));
+
+ 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;
@@ -855,15 +865,23 @@ 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);
+ /* start the cycle over again */
+ wrmsrl(wd->perfctr_msr,
+ -((u64)cpu_khz * 1000 / nmi_hz));
} 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);
+ /* 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));
}
- /* 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.