On Power8 we can freeze PMC5 and 6 if we're not using them. Normally they
run all the time.
Signed-off-by: Michael Ellerman <mich...@ellerman.id.au>
---
arch/powerpc/include/asm/reg.h | 1 +
arch/powerpc/perf/power8-pmu.c | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 4a9e408..362142b 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -626,6 +626,7 @@
#define MMCR0_TRIGGER 0x00002000UL /* TRIGGER enable */
#define MMCR0_PMAO 0x00000080UL /* performance monitor alert has occurred,
set to 0 after handling exception */
#define MMCR0_SHRFC 0x00000040UL /* SHRre freeze conditions between threads
*/
+#define MMCR0_FC56 0x00000010UL /* freeze counters 5 and 6 */
#define MMCR0_FCTI 0x00000008UL /* freeze counters in tags inactive mode */
#define MMCR0_FCTA 0x00000004UL /* freeze counters in tags active mode */
#define MMCR0_FCWAIT 0x00000002UL /* freeze counter in WAIT state */
diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c
index f7d1c4f..e791c68 100644
--- a/arch/powerpc/perf/power8-pmu.c
+++ b/arch/powerpc/perf/power8-pmu.c
@@ -378,6 +378,10 @@ static int power8_compute_mmcr(u64 event[], int n_ev,
if (pmc_inuse & 0x7c)
mmcr[0] |= MMCR0_PMCjCE;
+ /* If we're not using PMC 5 or 6, freeze them */
+ if (!(pmc_inuse & 0x60))
+ mmcr[0] |= MMCR0_FC56;
+
mmcr[1] = mmcr1;
mmcr[2] = mmcra;
--
1.7.10.4
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