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;