@@ -1412,11 +1412,8 @@ unsigned long perf_instruction_pointer(struct pt_regs *regs)
return regs->nip;
}
-static bool pmc_overflow(unsigned long val)
+static bool pmc_overflow_power7(unsigned long val)
{
- if ((int)val < 0)
- return true;
-
/*
* Events on POWER7 can roll back if a speculative event doesn't
* eventually complete. Unfortunately in some rare cases they will
@@ -1428,7 +1425,15 @@ static bool pmc_overflow(unsigned long val)
* PMCs because a user might set a period of less than 256 and we
* don't want to mistakenly reset them.
*/
- if (pvr_version_is(PVR_POWER7) && ((0x80000000 - val) <= 256))
+ if ((0x80000000 - val) <= 256)
+ return true;
+
+ return false;
+}
+
+static bool pmc_overflow(unsigned long val)
+{
+ if ((int)val < 0)
return true;
return false;
@@ -1439,11 +1444,11 @@ static bool pmc_overflow(unsigned long val)
*/
static void perf_event_interrupt(struct pt_regs *regs)
{
- int i;
+ int i, j;
struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
struct perf_event *event;
- unsigned long val;
- int found = 0;
+ unsigned long val[8];
+ int found, active;
int nmi;
if (cpuhw->n_limited)
@@ -1458,33 +1463,53 @@ static void perf_event_interrupt(struct pt_regs *regs)
else
irq_enter();
- for (i = 0; i < cpuhw->n_events; ++i) {
- event = cpuhw->event[i];
- if (!event->hw.idx || is_limited_pmc(event->hw.idx))
+ /* Read all the PMCs since we'll need them a bunch of times */
+ for (i = 0; i < ppmu->n_counter; ++i)
+ val[i] = read_pmc(i + 1);
+
+ /* Try to find what caused the IRQ */
+ found = 0;
+ for (i = 0; i < ppmu->n_counter; ++i) {
+ if (!pmc_overflow(val[i]))
continue;
- val = read_pmc(event->hw.idx);
- if ((int)val < 0) {
- /* event has overflowed */
- found = 1;
- record_and_restart(event, val, regs);
+ if (is_limited_pmc(i + 1))
+ continue; /* these won't generate IRQs */
+ /*
+ * We've found one that's overflowed. For active
+ * counters we need to log this. For inactive
+ * counters, we need to reset it anyway
+ */
+ found = 1;
+ active = 0;
+ for (j = 0; j < cpuhw->n_events; ++j) {
+ event = cpuhw->event[j];
+ if (event->hw.idx == (i + 1)) {
+ active = 1;
+ record_and_restart(event, val[i], regs);
+ break;
+ }
}
+ if (!active)
+ /* reset non active counters that have overflowed */
+ write_pmc(i + 1, 0);
}
-
- /*
- * In case we didn't find and reset the event that caused
- * the interrupt, scan all events and reset any that are
- * negative, to avoid getting continual interrupts.
- * Any that we processed in the previous loop will not be negative.
- */
- if (!found) {
- for (i = 0; i < ppmu->n_counter; ++i) {
- if (is_limited_pmc(i + 1))
+ if (!found && pvr_version_is(PVR_POWER7)) {
+ /* check active counters for special buggy p7 overflow */
+ for (i = 0; i < cpuhw->n_events; ++i) {
+ event = cpuhw->event[i];
+ if (!event->hw.idx || is_limited_pmc(event->hw.idx))
continue;
- val = read_pmc(i + 1);
- if (pmc_overflow(val))
- write_pmc(i + 1, 0);
+ if (pmc_overflow_power7(val[event->hw.idx - 1])) {
+ /* event has overflowed in a buggy way*/
+ found = 1;
+ record_and_restart(event,
+ val[event->hw.idx - 1],
+ regs);
+ }
}
}
+ if ((!found) && printk_ratelimit())
+ printk(KERN_WARNING "Can't find PMC that caused IRQ\n");
/*
* Reset MMCR0 to its normal value. This will set PMXE and