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| author | Mathieu Poirier <mathieu.poirier@linaro.org> | 2019-04-25 13:53:05 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-25 22:00:18 +0200 |
| commit | 57549999b9a0d0c72900d2413ef1e3168bd2e817 (patch) | |
| tree | e4ddd36976b85826122166c2837a7f20a9bb49c5 /drivers/hwtracing | |
| parent | ef848e463ac9052be620757579cfa0aa975e97ea (diff) | |
| download | linux-57549999b9a0d0c72900d2413ef1e3168bd2e817.tar.bz2 | |
coresight: tmc-etr: Introduce the notion of reference counting to ETR devices
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>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etr.c | 5 | ||||
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc.h | 3 |
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 1acad42184e6..de33c0391186 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> @@ -1222,7 +1223,11 @@ 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; |