In preparation to support CPU-wide trace scenarios, add the notion of process ID to ETR devices so that memory buffers can be shared between events.
Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org --- .../hwtracing/coresight/coresight-tmc-etr.c | 22 +++++++++++++++++-- drivers/hwtracing/coresight/coresight-tmc.h | 3 +++ 2 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 79fee9341446..7254fafdf1c2 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -26,6 +26,7 @@ struct etr_flat_buf { /* * etr_perf_buffer - Perf buffer used for ETR * @etr_buf - Actual buffer used by the ETR + * @pid - The PID this etr_perf_buffer belongs to. * @snaphost - Perf session mode * @head - handle->head at the beginning of the session. * @nr_pages - Number of pages in the ring buffer. @@ -33,6 +34,7 @@ struct etr_flat_buf { */ struct etr_perf_buffer { struct etr_buf *etr_buf; + pid_t pid; bool snapshot; unsigned long head; int nr_pages; @@ -1160,8 +1162,8 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) }
static struct etr_buf * -tmc_etr_get_etr_buf(struct tmc_drvdata *drvdata, int node, - int nr_pages, void **pages) +alloc_etr_buf(struct tmc_drvdata *drvdata, int node, + int nr_pages, void **pages) { struct etr_buf *etr_buf; unsigned long size; @@ -1195,6 +1197,20 @@ tmc_etr_get_etr_buf(struct tmc_drvdata *drvdata, int node, return etr_buf; }
+static struct etr_buf * +tmc_etr_get_etr_buf(struct tmc_drvdata *drvdata, int node, + int nr_pages, void **pages) +{ + struct etr_buf *etr_buf; + + etr_buf = alloc_etr_buf(drvdata, node, nr_pages, pages); + if (IS_ERR(etr_buf)) + return etr_buf; + + refcount_set(&etr_buf->refcount, 1); + return etr_buf; +} + /* * tmc_etr_setup_perf_buf: Allocate ETR buffer for use by perf. * The size of the hardware buffer is dependent on the size configured @@ -1231,6 +1247,7 @@ static void *tmc_alloc_etr_buffer(struct coresight_device *csdev, int nr_pages, bool snapshot) { int cpu = event->cpu; + pid_t pid = task_pid_nr(event->owner); struct etr_perf_buffer *etr_perf; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -1244,6 +1261,7 @@ static void *tmc_alloc_etr_buffer(struct coresight_device *csdev, return NULL; }
+ etr_perf->pid = pid; etr_perf->snapshot = snapshot; etr_perf->nr_pages = nr_pages; etr_perf->pages = pages; diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 487c53701e9c..7675138ff9fc 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;