[PATCH 10/14] coresight: tmc: make sysFS and Perf mode mutually exclusive
Mathieu Poirier
mathieu.poirier at linaro.org
Tue Mar 22 13:23:18 PDT 2016
The sysFS and Perf access methods can't be allowed to interfere
with one another. As such introducing guards to access
functions that prevents moving forward if a TMC is already
being used.
Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 76 +++++++++++++++++++++---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 77 ++++++++++++++++++++++---
2 files changed, 139 insertions(+), 14 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index a88c76d7f473..c533b4494969 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -106,7 +106,7 @@ static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata)
CS_LOCK(drvdata->base);
}
-static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
+static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
{
u32 val;
bool allocated = false;
@@ -127,6 +127,12 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
}
val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+ /* No need to continue if already operated from Perf */
+ if (val == CS_MODE_PERF) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ kfree(buf);
+ return -EBUSY;
+ }
/*
* 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
@@ -162,7 +168,7 @@ out:
return 0;
}
-static void tmc_disable_etf_sink(struct coresight_device *csdev)
+static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
{
u32 val;
unsigned long flags;
@@ -171,16 +177,66 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+ /*
+ * In Perf mode there can be only one writer per sink. There
+ * is also no need to continue if the ETB/ETR is already operated
+ * from sysFS.
+ */
+ if (val != CS_MODE_DISABLED) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ tmc_etb_enable_hw(drvdata);
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ return 0;
+}
+
+static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
+{
+ switch (mode) {
+ case CS_MODE_SYSFS:
+ return tmc_enable_etf_sink_sysfs(csdev, mode);
+ case CS_MODE_PERF:
+ return tmc_enable_etf_sink_perf(csdev, mode);
+ }
+
+ /* We shouldn't be here */
+ return -EINVAL;
+}
+
+static void tmc_disable_etf_sink(struct coresight_device *csdev)
+{
+ u32 mode;
+ unsigned long flags;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (drvdata->reading) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
return;
}
- val = local_cmpxchg(&drvdata->mode, CS_MODE_SYSFS, CS_MODE_DISABLED);
- /* Nothing to do, the TMC was already disabled */
- if (val == CS_MODE_DISABLED)
+ mode = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
+ /* Nothing to do, the ETB/ETF was already disabled */
+ if (mode == CS_MODE_DISABLED)
goto out;
+ /* The engine has to be stopped in both sysFS and Perf mode */
tmc_etb_disable_hw(drvdata);
- tmc_etb_dump_hw(drvdata);
+
+ /*
+ * If we operated from sysFS, dump the trace data for retrieval
+ * via /dev/. From Perf trace data is handled via the Perf ring
+ * buffer.
+ */
+ if (mode == CS_MODE_SYSFS)
+ tmc_etb_dump_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -253,7 +309,13 @@ int tmc_read_prepare_etf(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
- /* The TMC isn't enabled, so there is no need to disable it */
+ /* Don't interfere if operated from Perf */
+ if (local_read(&drvdata->mode) == CS_MODE_PERF) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ /* The ETB/ETF isn't enabled, so there is no need to disable it */
if (local_read(&drvdata->mode) == CS_MODE_DISABLED) {
/*
* The ETB/ETF is disabled already. If drvdata::buf is NULL
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 540d0b96a958..50a2e0a83714 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -82,7 +82,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
CS_LOCK(drvdata->base);
}
-static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
+static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
{
u32 val;
bool allocated = false;
@@ -109,6 +109,13 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
}
val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+ /* No need to continue if already operated from Perf */
+ if (val == CS_MODE_PERF) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
+ return -EBUSY;
+ }
+
/*
* 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
@@ -143,7 +150,7 @@ out:
return 0;
}
-static void tmc_disable_etr_sink(struct coresight_device *csdev)
+static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
{
u32 val;
unsigned long flags;
@@ -152,16 +159,66 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+ /*
+ * In Perf mode there can be only one writer per sink. There
+ * is also no need to continue if the ETR is already operated
+ * from sysFS.
+ */
+ if (val != CS_MODE_DISABLED) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ tmc_etr_enable_hw(drvdata);
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ return 0;
+}
+
+static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
+{
+ switch (mode) {
+ case CS_MODE_SYSFS:
+ return tmc_enable_etr_sink_sysfs(csdev, mode);
+ case CS_MODE_PERF:
+ return tmc_enable_etr_sink_perf(csdev, mode);
+ }
+
+ /* We shouldn't be here */
+ return -EINVAL;
+}
+
+static void tmc_disable_etr_sink(struct coresight_device *csdev)
+{
+ u32 mode;
+ unsigned long flags;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (drvdata->reading) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
return;
}
- val = local_cmpxchg(&drvdata->mode, CS_MODE_SYSFS, CS_MODE_DISABLED);
- /* Nothing to do, the TMC was already disabled */
- if (val == CS_MODE_DISABLED)
+ mode = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
+ /* Nothing to do, the ETR was already disabled */
+ if (mode == CS_MODE_DISABLED)
goto out;
+ /* The engine has to be stopped in both sysFS and Perf mode */
tmc_etr_disable_hw(drvdata);
- tmc_etr_dump_hw(drvdata);
+
+ /*
+ * If we operated from sysFS, dump the trace data for retrieval
+ * via /dev/. From Perf trace data is handled via the Perf ring
+ * buffer.
+ */
+ if (mode == CS_MODE_SYSFS)
+ tmc_etr_dump_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -184,7 +241,13 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
- /* The TMC isn't enabled, so there is no need to disable it */
+ /* Don't interfere if operated from Perf */
+ if (local_read(&drvdata->mode) == CS_MODE_PERF) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ /* The ETR isn't enabled, so there is no need to disable it */
if (local_read(&drvdata->mode) == CS_MODE_DISABLED) {
/*
* The ETR is disabled already. If drvdata::buf is NULL
--
2.1.4
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