From 0916447c8728ed1ffa2bf9feee220f01d802b37e Mon Sep 17 00:00:00 2001 From: Mathieu Poirier Date: Thu, 25 Apr 2019 13:52:58 -0600 Subject: coresight: Properly address concurrency in sink::update() functions When operating in CPU-wide trace scenarios and working with an N:1 source/sink HW topology, update() functions need to be made atomic in order to avoid racing with start and stop operations. Signed-off-by: Mathieu Poirier Reviewed-by: Suzuki K Poulose Tested-by: Leo Yan Tested-by: Robert Walker Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-tmc-etf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/hwtracing/coresight/coresight-tmc-etf.c') diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 30f868676540..a38ad2b0d95a 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -413,7 +413,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, u32 *buf_ptr; u64 read_ptr, write_ptr; u32 status; - unsigned long offset, to_read; + unsigned long offset, to_read, flags; struct cs_buffers *buf = sink_config; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -424,6 +424,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF)) return 0; + spin_lock_irqsave(&drvdata->spinlock, flags); CS_UNLOCK(drvdata->base); tmc_flush_and_stop(drvdata); @@ -517,6 +518,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, to_read = buf->nr_pages << PAGE_SHIFT; } CS_LOCK(drvdata->base); + spin_unlock_irqrestore(&drvdata->spinlock, flags); return to_read; } -- cgit v1.2.3-59-g8ed1b