[PATCH] powerpc/perf: Update MMCR2 to support event exclude_idle
Madhavan Srinivasan
maddy at linux.ibm.com
Thu Apr 29 15:02:08 AEST 2021
struct perf_event_attr supports exclude counting of idle task.
This is sent to kernel via perf_event_attr.exclude_idle and
in perf tool, user can use ":I" event modifier to enable this
for specific event.
Monitor Mode Control Register 2 (MMCR2) SPR has control bits
for each PMCs to freeze counting based on the Control Register
CTRL[RUN] state. CTRL[RUN] is not set when idle task is
running. Patch adds a check for event attr.exclude_idle to
set MMCR2[FCnWAIT] bit.
Signed-off-by: Madhavan Srinivasan <maddy at linux.ibm.com>
---
arch/powerpc/perf/isa207-common.c | 3 +++
arch/powerpc/perf/isa207-common.h | 1 +
2 files changed, 4 insertions(+)
diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
index e4f577da33d8..5e05f90dd7df 100644
--- a/arch/powerpc/perf/isa207-common.c
+++ b/arch/powerpc/perf/isa207-common.c
@@ -587,6 +587,9 @@ int isa207_compute_mmcr(u64 event[], int n_ev,
mmcr2 |= MMCR2_FCS(pmc);
}
+ if (pevents[i]->attr.exclude_idle)
+ mmcr2 |= MMCR2_FCWAIT(pmc);
+
if (cpu_has_feature(CPU_FTR_ARCH_31)) {
if (pmc <= 4) {
val = (event[i] >> p10_EVENT_MMCR3_SHIFT) &
diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h
index 1af0e8c97ac7..a95a810fa832 100644
--- a/arch/powerpc/perf/isa207-common.h
+++ b/arch/powerpc/perf/isa207-common.h
@@ -248,6 +248,7 @@
/* Bits in MMCR2 for PowerISA v2.07 */
#define MMCR2_FCS(pmc) (1ull << (63 - (((pmc) - 1) * 9)))
#define MMCR2_FCP(pmc) (1ull << (62 - (((pmc) - 1) * 9)))
+#define MMCR2_FCWAIT(pmc) (1ull << (58 - (((pmc) - 1) * 9)))
#define MMCR2_FCH(pmc) (1ull << (57 - (((pmc) - 1) * 9)))
#define MAX_ALT 2
--
2.26.2
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