linux-kernel - [PATCH V5 5/9] perf: Passing struct perf_event to function setup

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Message-Id: <1470932464-726-6-git-send-email-mathieu.poirier@linaro.org>
Date:	Thu, 11 Aug 2016 10:21:00 -0600
From:	Mathieu Poirier <mathieu.poirier@...aro.org>
To:	peterz@...radead.org
Cc:	acme@...nel.org, jolsa@...nel.org, mingo@...hat.com,
	vince@...ter.net, mtk.manpages@...il.com,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	Mathieu Poirier <mathieu.poirier@...aro.org>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Subject: [PATCH V5 5/9] perf: Passing struct perf_event to function setup_aux()

Some information, like driver specific configuration, is found
in the hw_perf_event structure.  As such pass a 'struct perf_event'
to function setup_aux() rather than just the CPU number so that
individual drivers can make the right configuration when setting
up a session.

For example the sink definition for a given CoreSight session can be
embedded in the perf cmd line:

perf record -e cs_etm/@...k=20070000.etr/ ...

The string "sink=20070000.etr" is conveyed to the kernel by way of
of an ioctl() call.  From there is is handed over to the PMU driver
for parsing and processing.  If the format is valid the substring
"20070000.etr" is kept in the hw_perf_event::drv_configs for future
reference.

When pmu::setup_aux() is called information about both the
perf_event::cpu and the hw_perf_event::drv_configs is needed to setup
a path from source to sink.

Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
Cc: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
---
 arch/x86/events/intel/bts.c                      | 4 +++-
 arch/x86/events/intel/pt.c                       | 5 +++--
 drivers/hwtracing/coresight/coresight-etm-perf.c | 4 ++--
 include/linux/perf_event.h                       | 2 +-
 kernel/events/ring_buffer.c                      | 2 +-
 5 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index 0a6e393a2e62..98155c2dfcce 100644
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -68,8 +68,10 @@ static size_t buf_size(struct page *page)
 }
 
 static void *
-bts_buffer_setup_aux(int cpu, void **pages, int nr_pages, bool overwrite)
+bts_buffer_setup_aux(struct perf_event *event, void **pages,
+		     int nr_pages, bool overwrite)
 {
+	int cpu = event->cpu;
 	struct bts_buffer *buf;
 	struct page *page;
 	int node = (cpu == -1) ? cpu : cpu_to_node(cpu);
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 04bb5fb5a8d7..5178c5de0b19 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -1003,10 +1003,11 @@ static int pt_buffer_init_topa(struct pt_buffer *buf, unsigned long nr_pages,
  * Return:	Our private PT buffer structure.
  */
 static void *
-pt_buffer_setup_aux(int cpu, void **pages, int nr_pages, bool snapshot)
+pt_buffer_setup_aux(struct perf_event *event, void **pages,
+		    int nr_pages, bool snapshot)
 {
 	struct pt_buffer *buf;
-	int node, ret;
+	int node, ret, cpu = event->cpu;
 
 	if (!nr_pages)
 		return NULL;
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 755125f7917f..f4174f36c5a0 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -155,7 +155,7 @@ static void etm_free_aux(void *data)
 	schedule_work(&event_data->work);
 }
 
-static void *etm_setup_aux(int event_cpu, void **pages,
+static void *etm_setup_aux(struct perf_event *event, void **pages,
 			   int nr_pages, bool overwrite)
 {
 	int cpu;
@@ -163,7 +163,7 @@ static void *etm_setup_aux(int event_cpu, void **pages,
 	struct coresight_device *sink;
 	struct etm_event_data *event_data = NULL;
 
-	event_data = alloc_event_data(event_cpu);
+	event_data = alloc_event_data(event->cpu);
 	if (!event_data)
 		return NULL;
 
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 1ea2028d9848..16f797561907 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -421,7 +421,7 @@ struct pmu {
 	/*
 	 * Set up pmu-private data structures for an AUX area
 	 */
-	void *(*setup_aux)		(int cpu, void **pages,
+	void *(*setup_aux)		(struct perf_event *event, void **pages,
 					 int nr_pages, bool overwrite);
 					/* optional */
 
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index ae9b90dc9a5a..56aba90af437 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -616,7 +616,7 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
 			goto out;
 	}
 
-	rb->aux_priv = event->pmu->setup_aux(event->cpu, rb->aux_pages, nr_pages,
+	rb->aux_priv = event->pmu->setup_aux(event, rb->aux_pages, nr_pages,
 					     overwrite);
 	if (!rb->aux_priv)
 		goto out;
-- 
2.7.4