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From:   kan.liang@linux.intel.com
To:     peterz@infradead.org, mingo@redhat.com,
        linux-kernel@vger.kernel.org
Cc:     acme@kernel.org, tglx@linutronix.de, jolsa@redhat.com,
        eranian@google.com, ak@linux.intel.com,
        Kan Liang <kan.liang@linux.intel.com>
Subject: [PATCH V4 2/5] perf/x86: Introduce read function for x86_pmu
Date:   Mon, 12 Feb 2018 14:20:32 -0800
Message-Id: <1518474035-21006-3-git-send-email-kan.liang@linux.intel.com>
In-Reply-To: <1518474035-21006-1-git-send-email-kan.liang@linux.intel.com>
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From: Kan Liang <kan.liang@linux.intel.com>

Auto-reload needs to be specially handled in event count read.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
 arch/x86/events/core.c       | 2 ++
 arch/x86/events/perf_event.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 5a3ccd1..00a6251 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1881,6 +1881,8 @@ early_initcall(init_hw_perf_events);
 
 static inline void x86_pmu_read(struct perf_event *event)
 {
+	if (x86_pmu.read)
+		return x86_pmu.read(event);
 	x86_perf_event_update(event);
 }
 
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 8e4ea143..805400b 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -519,6 +519,7 @@ struct x86_pmu {
 	void		(*disable)(struct perf_event *);
 	void		(*add)(struct perf_event *);
 	void		(*del)(struct perf_event *);
+	void		(*read)(struct perf_event *event);
 	int		(*hw_config)(struct perf_event *event);
 	int		(*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign);
 	unsigned	eventsel;
-- 
2.7.4