linux-kernel - [PATCH 1/2] perf/x86/intel: Support adaptive PEBS for fixed counters

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Date:   Tue,  9 Apr 2019 18:09:59 -0700
From:   kan.liang@...ux.intel.com
To:     peterz@...radead.org, mingo@...hat.com,
        linux-kernel@...r.kernel.org
Cc:     tglx@...utronix.de, acme@...nel.org, jolsa@...nel.org,
        eranian@...gle.com, alexander.shishkin@...ux.intel.com,
        ak@...ux.intel.com, Kan Liang <kan.liang@...ux.intel.com>
Subject: [PATCH 1/2] perf/x86/intel: Support adaptive PEBS for fixed counters

From: Kan Liang <kan.liang@...ux.intel.com>

Fixed counters can also generate adaptive PEBS record, if the
corresponding bit in IA32_FIXED_CTR_CTRL is set.
Otherwise, only basic record is generated.

Unconditionally set the bit when PEBS is enabled on fixed counters.
Let MSR_PEBS_CFG decide which format of PEBS record should be generated.
There is no harmful to leave the bit set.

Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
---
 arch/x86/events/intel/core.c      | 5 +++++
 arch/x86/include/asm/perf_event.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 56df0f6..f34d92b 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2174,6 +2174,11 @@ static void intel_pmu_enable_fixed(struct perf_event *event)
 	bits <<= (idx * 4);
 	mask = 0xfULL << (idx * 4);
 
+	if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip) {
+		bits |= ICL_FIXED_0_ADAPTIVE << (idx * 4);
+		mask |= ICL_FIXED_0_ADAPTIVE << (idx * 4);
+	}
+
 	rdmsrl(hwc->config_base, ctrl_val);
 	ctrl_val &= ~mask;
 	ctrl_val |= bits;
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index dcb8bac..ce0dc88 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -33,6 +33,7 @@
 #define HSW_IN_TX					(1ULL << 32)
 #define HSW_IN_TX_CHECKPOINTED				(1ULL << 33)
 #define ICL_EVENTSEL_ADAPTIVE				(1ULL << 34)
+#define ICL_FIXED_0_ADAPTIVE				(1ULL << 32)
 
 #define AMD64_EVENTSEL_INT_CORE_ENABLE			(1ULL << 36)
 #define AMD64_EVENTSEL_GUESTONLY			(1ULL << 40)
-- 
2.7.4