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From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: alexander.shishkin@linux.intel.com, peterz@infradead.org,
	suzuki.poulose@arm.com, mike.leach@arm.com, leo.yan@linaro.org,
	coresight@lists.linaro.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 15/20] coresight: tmc-etr: Introduce the notion of reference counting to ETR devices
Date: Wed,  3 Apr 2019 21:35:36 -0600	[thread overview]
Message-ID: <20190404033541.14072-16-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20190404033541.14072-1-mathieu.poirier@linaro.org>

This patch adds reference counting to struct etr_buf so that, in CPU-wide
trace scenarios, shared buffers can be disposed of when no longer used.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 5 +++++
 drivers/hwtracing/coresight/coresight-tmc.h     | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index e1774d4bb5f3..1346474ac019 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -8,6 +8,7 @@
 #include <linux/coresight.h>
 #include <linux/dma-mapping.h>
 #include <linux/iommu.h>
+#include <linux/refcount.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/vmalloc.h>
@@ -1221,7 +1222,11 @@ get_perf_etr_buf_per_thread(struct tmc_drvdata *drvdata,
 	 * with memory allocation.
 	 */
 	etr_buf = alloc_etr_buf(drvdata, event, nr_pages, pages, snapshot);
+	if (IS_ERR(etr_buf))
+		goto out;
 
+	refcount_set(&etr_buf->refcount, 1);
+out:
 	return etr_buf;
 }
 
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 487c53701e9c..ee44906dffe8 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -9,6 +9,7 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/miscdevice.h>
+#include <linux/refcount.h>
 
 #define TMC_RSZ			0x004
 #define TMC_STS			0x00c
@@ -133,6 +134,7 @@ struct etr_buf_operations;
 
 /**
  * struct etr_buf - Details of the buffer used by ETR
+ * refcount	; Number of sources currently using this etr_buf.
  * @mode	: Mode of the ETR buffer, contiguous, Scatter Gather etc.
  * @full	: Trace data overflow
  * @size	: Size of the buffer.
@@ -143,6 +145,7 @@ struct etr_buf_operations;
  * @private	: Backend specific information for the buf
  */
 struct etr_buf {
+	refcount_t			refcount;
 	enum etr_mode			mode;
 	bool				full;
 	ssize_t				size;
-- 
2.17.1


  parent reply	other threads:[~2019-04-04  3:36 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-04  3:35 [PATCH v3 00/20] coresight: Add support for CPU-wide trace scenarios Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 01/20] coresight: pmu: Adding ITRACE property to cs_etm PMU Mathieu Poirier
2019-04-04  8:48   ` Suzuki K Poulose
2019-04-04  3:35 ` [PATCH v3 02/20] coresight: etm4x: Add kernel configuration for CONTEXTID Mathieu Poirier
2019-04-04  8:53   ` Suzuki K Poulose
2019-04-04  3:35 ` [PATCH v3 03/20] coresight: etm4x: Skip selector pair 0 Mathieu Poirier
2019-04-04  8:50   ` Suzuki K Poulose
2019-04-04  3:35 ` [PATCH v3 04/20] coresight: etm4x: Configure tracers to emit timestamps Mathieu Poirier
2019-04-04  4:47   ` Mike Leach
2019-04-04  3:35 ` [PATCH v3 05/20] coresight: Adding return code to sink::disable() operation Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 06/20] coresight: Move reference counting inside sink drivers Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 07/20] coresight: Properly address errors in sink::disable() functions Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 08/20] coresight: Properly address concurrency in sink::update() functions Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 09/20] coresight: perf: Clean up function etm_setup_aux() Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 10/20] coresight: perf: Refactor function free_event_data() Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 11/20] coresight: Communicate perf event to sink buffer allocation functions Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 12/20] coresight: tmc-etr: Refactor function tmc_etr_setup_perf_buf() Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 13/20] coresight: tmc-etr: Create per-thread buffer allocation function Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 14/20] coresight: tmc-etr: Introduce the notion of process ID to ETR devices Mathieu Poirier
2019-04-04  3:35 ` Mathieu Poirier [this message]
2019-04-04  3:35 ` [PATCH v3 16/20] coresight: tmc-etr: Introduce the notion of IDR " Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 17/20] coresight: tmc-etr: Allocate and free ETR memory buffers for CPU-wide scenarios Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 18/20] coresight: tmc-etr: Add support for CPU-wide trace scenarios Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 19/20] coresight: tmc-etf: " Mathieu Poirier
2019-04-04  3:35 ` [PATCH v3 20/20] coresight: etb10: " Mathieu Poirier

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