diff options
| author | Mathieu Poirier <mathieu.poirier@linaro.org> | 2016-05-03 11:33:54 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-03 14:59:30 -0700 |
| commit | f2facc3366d77e78dbc8bf865f1e4a6227a7f0e5 (patch) | |
| tree | b5c0639e99149f1312344e8f0f18b7cebf55eff0 /drivers/hwtracing/coresight/coresight-tmc-etr.c | |
| parent | f74debbea0885ebb65fb3fa4e598323f40b03f5f (diff) | |
coresight: tmc: adding mode of operation for link/sinks
Moving tmc_drvdata::enable to a local_t mode. That way the
sink interface is aware of it's orgin and the foundation for
mutual exclusion between the sysFS and Perf interface can be
laid out.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-tmc-etr.c')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etr.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index d6999b457fb8..0c107811a232 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -86,6 +86,7 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode) { int ret = 0; bool used = false; + long val; unsigned long flags; void __iomem *vaddr = NULL; dma_addr_t paddr; @@ -122,6 +123,15 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode) goto out; } + val = local_xchg(&drvdata->mode, mode); + /* + * In sysFS mode we can have multiple writers per sink. Since this + * sink is already enabled no memory is needed and the HW need not be + * touched. + */ + if (val == CS_MODE_SYSFS) + goto out; + /* * If drvdata::buf == NULL, use the memory allocated above. * Otherwise a buffer still exists from a previous session, so @@ -137,7 +147,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode) memset(drvdata->vaddr, 0, drvdata->size); tmc_etr_enable_hw(drvdata); - drvdata->enable = true; out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -153,6 +162,7 @@ out: static void tmc_disable_etr_sink(struct coresight_device *csdev) { + long val; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -162,8 +172,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev) return; } - tmc_etr_disable_hw(drvdata); - drvdata->enable = false; + val = local_xchg(&drvdata->mode, CS_MODE_DISABLED); + /* Disable the TMC only if it needs to */ + if (val != CS_MODE_DISABLED) + tmc_etr_disable_hw(drvdata); + spin_unlock_irqrestore(&drvdata->spinlock, flags); dev_info(drvdata->dev, "TMC-ETR disabled\n"); @@ -200,7 +213,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) } /* Disable the TMC if need be */ - if (drvdata->enable) + if (local_read(&drvdata->mode) == CS_MODE_SYSFS) tmc_etr_disable_hw(drvdata); drvdata->reading = true; @@ -223,7 +236,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) spin_lock_irqsave(&drvdata->spinlock, flags); /* RE-enable the TMC if need be */ - if (drvdata->enable) { + if (local_read(&drvdata->mode) == CS_MODE_SYSFS) { /* * The trace run will continue with the same allocated trace * buffer. As such zero-out the buffer so that we don't end |