In snapshot mode the buffer used by the sink devices need to be equal to the ring buffer size in order for the user space mechanic to work properly.
Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org --- drivers/hwtracing/coresight/coresight-etb10.c | 23 +++++++++++++++++++ .../hwtracing/coresight/coresight-tmc-etf.c | 20 ++++++++++++++++ .../hwtracing/coresight/coresight-tmc-etr.c | 8 +++++-- 3 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index 4ee4c80a4354..0764647b92bc 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -374,7 +374,30 @@ static void *etb_alloc_buffer(struct coresight_device *csdev, int nr_pages, bool overwrite) { int node, cpu = event->cpu; + u32 capacity; struct cs_buffers *buf; + struct etb_drvdata *drvdata; + + /* + * In snapsot mode the size of the perf ring buffer needs to be equal + * to the size of the device's internal memory if we want to reuse the + * generic AUX buffer management mechanic. + * + * For example (assuming 4096 byte page size): + * + * # cat /sys/bus/coresight/devices/20010000.etb/mgmt/rdp + * 0x2000 + * # perf record -e cs_etm/@20010000.etf/ -S -m,8 --per-thread $APP + * + */ + drvdata = dev_get_drvdata(csdev->dev.parent); + capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS; + + if (overwrite && + ((nr_pages << PAGE_SHIFT) != capacity)) { + dev_err(&csdev->dev, "Ring buffer not equal to device buffer"); + return NULL; + }
if (cpu == -1) cpu = smp_processor_id(); diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 2527b5d3b65e..7694833b13cb 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -380,6 +380,26 @@ static void *tmc_alloc_etf_buffer(struct coresight_device *csdev, { int node, cpu = event->cpu; struct cs_buffers *buf; + struct tmc_drvdata *drvdata; + + /* + * In snapsot mode the size of the perf ring buffer needs to be equal + * to the size of the device's internal memory if we want to reuse the + * generic AUX buffer management mechanic. + * + * For example (assuming 4096 byte page size): + * + * # cat /sys/bus/coresight/devices/20010000.etf/buffer_size + * 0x10000 + * # perf record -e cs_etm/@20010000.etf/ -S -m,16 --per-thread $APP + * + */ + drvdata = dev_get_drvdata(csdev->dev.parent); + if (overwrite && + ((nr_pages << PAGE_SHIFT) != drvdata->size)) { + dev_err(&csdev->dev, "Ring buffer not equal to device buffer"); + return NULL; + }
if (cpu == -1) cpu = smp_processor_id(); diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index df6e4b0b84e9..b9881d6d41ba 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1188,9 +1188,13 @@ alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
/* * Try to match the perf ring buffer size if it is larger - * than the size requested via sysfs. + * than the size requested via sysfs. In snapsot mode the size + * of the perf ring buffer needs to be equal to the allocated + * size if we want to reuse the generic AUX buffer management + * mechanic. */ - if ((nr_pages << PAGE_SHIFT) > drvdata->size) { + if (snapshot || + (nr_pages << PAGE_SHIFT) > drvdata->size) { etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT), 0, node, NULL); if (!IS_ERR(etr_buf))