powerpc/perf: Update MMCR2 to support event exclude_idle

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@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210429050208.266619-1-maddy@linux.ibm.com

diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
index 42abbcfc73da1f5631ece275374d4c1d0eff6b65..56301b2bc8ae87e8e3c94987f6bd224adfbf4d4f 100644 (file)
--- a/arch/powerpc/perf/isa207-common.c
+++ b/arch/powerpc/perf/isa207-common.c
@@ -686,6 +686,9 @@ 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 ff122603989bdc131606672e524cb3d3064c0e57..f594fa6580d1486cce48f8c8f8eeb56aa423b808 100644 (file)
--- a/arch/powerpc/perf/isa207-common.h
+++ b/arch/powerpc/perf/isa207-common.h
@@ -249,6 +249,7 @@
 /* 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