The following commit has been merged into the perf/core branch of tip:
Commit-ID: 6f7225099d5f3ec3019f380a0da2b456b7796cb0
Gitweb: https://git.kernel.org/tip/6f7225099d5f3ec3019f380a0da2b456b7796cb0
Author: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
AuthorDate: Thu, 23 Jul 2020 10:11:06 -07:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 18 Aug 2020 16:34:35 +02:00
perf/x86/intel: Introduce the fourth fixed counter
The fourth fixed counter, TOPDOWN.SLOTS, is introduced in Ice Lake to
measure the level 1 TopDown events.
Add MSR address and macros for the new fixed counter, which will be used
in a later patch.
Add comments to explain the event encoding rules for the fixed counters.
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200723171117.9918-4-kan.liang@xxxxxxxxxxxxxxx
---
arch/x86/include/asm/perf_event.h | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index fd3eba6..fe8110a 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -197,12 +197,24 @@ struct x86_pmu_capability {
*/
/*
- * All 3 fixed-mode PMCs are configured via this single MSR:
+ * All the fixed-mode PMCs are configured via this single MSR:
*/
#define MSR_ARCH_PERFMON_FIXED_CTR_CTRL 0x38d
/*
- * The counts are available in three separate MSRs:
+ * There is no event-code assigned to the fixed-mode PMCs.
+ *
+ * For a fixed-mode PMC, which has an equivalent event on a general-purpose
+ * PMC, the event-code of the equivalent event is used for the fixed-mode PMC,
+ * e.g., Instr_Retired.Any and CPU_CLK_Unhalted.Core.
+ *
+ * For a fixed-mode PMC, which doesn't have an equivalent event, a
+ * pseudo-encoding is used, e.g., CPU_CLK_Unhalted.Ref and TOPDOWN.SLOTS.
+ * The pseudo event-code for a fixed-mode PMC must be 0x00.
+ * The pseudo umask-code is 0xX. The X equals the index of the fixed
+ * counter + 1, e.g., the fixed counter 2 has the pseudo-encoding 0x0300.
+ *
+ * The counts are available in separate MSRs:
*/
/* Instr_Retired.Any: */
@@ -213,11 +225,16 @@ struct x86_pmu_capability {
#define MSR_ARCH_PERFMON_FIXED_CTR1 0x30a
#define INTEL_PMC_IDX_FIXED_CPU_CYCLES (INTEL_PMC_IDX_FIXED + 1)
-/* CPU_CLK_Unhalted.Ref: */
+/* CPU_CLK_Unhalted.Ref: event=0x00,umask=0x3 (pseudo-encoding) */
#define MSR_ARCH_PERFMON_FIXED_CTR2 0x30b
#define INTEL_PMC_IDX_FIXED_REF_CYCLES (INTEL_PMC_IDX_FIXED + 2)
#define INTEL_PMC_MSK_FIXED_REF_CYCLES (1ULL << INTEL_PMC_IDX_FIXED_REF_CYCLES)
+/* TOPDOWN.SLOTS: event=0x00,umask=0x4 (pseudo-encoding) */
+#define MSR_ARCH_PERFMON_FIXED_CTR3 0x30c
+#define INTEL_PMC_IDX_FIXED_SLOTS (INTEL_PMC_IDX_FIXED + 3)
+#define INTEL_PMC_MSK_FIXED_SLOTS (1ULL << INTEL_PMC_IDX_FIXED_SLOTS)
+
/*
* We model BTS tracing as another fixed-mode PMC.
*
|