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-rw-r--r--arch/x86/kernel/cpu/perfctr-watchdog.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perfctr-watchdog.c b/arch/x86/kernel/cpu/perfctr-watchdog.c
index 05cc22dbd4f..62c01006397 100644
--- a/arch/x86/kernel/cpu/perfctr-watchdog.c
+++ b/arch/x86/kernel/cpu/perfctr-watchdog.c
@@ -432,6 +432,27 @@ static const struct wd_ops p6_wd_ops = {
#define P4_CCCR_ENABLE (1 << 12)
#define P4_CCCR_OVF (1 << 31)
+#define P4_CONTROLS 18
+static unsigned int p4_controls[18] = {
+ MSR_P4_BPU_CCCR0,
+ MSR_P4_BPU_CCCR1,
+ MSR_P4_BPU_CCCR2,
+ MSR_P4_BPU_CCCR3,
+ MSR_P4_MS_CCCR0,
+ MSR_P4_MS_CCCR1,
+ MSR_P4_MS_CCCR2,
+ MSR_P4_MS_CCCR3,
+ MSR_P4_FLAME_CCCR0,
+ MSR_P4_FLAME_CCCR1,
+ MSR_P4_FLAME_CCCR2,
+ MSR_P4_FLAME_CCCR3,
+ MSR_P4_IQ_CCCR0,
+ MSR_P4_IQ_CCCR1,
+ MSR_P4_IQ_CCCR2,
+ MSR_P4_IQ_CCCR3,
+ MSR_P4_IQ_CCCR4,
+ MSR_P4_IQ_CCCR5,
+};
/*
* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter
* CRU_ESCR0 (with any non-null event selector) through a complemented
@@ -473,6 +494,26 @@ static int setup_p4_watchdog(unsigned nmi_hz)
evntsel_msr = MSR_P4_CRU_ESCR0;
cccr_msr = MSR_P4_IQ_CCCR0;
cccr_val = P4_CCCR_OVF_PMI0 | P4_CCCR_ESCR_SELECT(4);
+
+ /*
+ * If we're on the kdump kernel or other situation, we may
+ * still have other performance counter registers set to
+ * interrupt and they'll keep interrupting forever because
+ * of the P4_CCCR_OVF quirk. So we need to ACK all the
+ * pending interrupts and disable all the registers here,
+ * before reenabling the NMI delivery. Refer to p4_rearm()
+ * about the P4_CCCR_OVF quirk.
+ */
+ if (reset_devices) {
+ unsigned int low, high;
+ int i;
+
+ for (i = 0; i < P4_CONTROLS; i++) {
+ rdmsr(p4_controls[i], low, high);
+ low &= ~(P4_CCCR_ENABLE | P4_CCCR_OVF);
+ wrmsr(p4_controls[i], low, high);
+ }
+ }
} else {
/* logical cpu 1 */
perfctr_msr = MSR_P4_IQ_PERFCTR1;