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.poir...@linaro.org>
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 28 ++++++++++++++++++-------
drivers/hwtracing/coresight/coresight-tmc-etr.c | 24 ++++++++++++++++-----
drivers/hwtracing/coresight/coresight-tmc.h | 4 ++--
3 files changed, 42 insertions(+), 14 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c
b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index bcfa40e8cd1c..d090a9745c73 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -110,6 +110,7 @@ static int tmc_enable_etf_sink(struct coresight_device
*csdev, u32 mode)
{
bool used = false;
char *buf = NULL;
+ long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -147,6 +148,15 @@ fast_path:
return -EBUSY;
}
+ 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 spin_unlock;
+
/*
* If drvdata::buf isn't NULL, memory was allocated for a previous
* trace run but wasn't read. If so simply zero-out the memory.
@@ -164,7 +174,7 @@ fast_path:
}
tmc_etb_enable_hw(drvdata);
- drvdata->enable = true;
+spin_unlock:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free memory outside the spinlock if need be */
@@ -177,6 +187,7 @@ fast_path:
static void tmc_disable_etf_sink(struct coresight_device *csdev)
{
+ long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -186,8 +197,11 @@ static void tmc_disable_etf_sink(struct coresight_device
*csdev)
return;
}
- tmc_etb_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_etb_disable_hw(drvdata);
+
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETB/ETF disabled\n");
@@ -206,7 +220,7 @@ static int tmc_enable_etf_link(struct coresight_device
*csdev,
}
tmc_etf_enable_hw(drvdata);
- drvdata->enable = true;
+ local_set(&drvdata->mode, CS_MODE_SYSFS);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETF enabled\n");
@@ -226,7 +240,7 @@ static void tmc_disable_etf_link(struct coresight_device
*csdev,
}
tmc_etf_disable_hw(drvdata);
- drvdata->enable = false;
+ local_set(&drvdata->mode, CS_MODE_DISABLED);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC disabled\n");
@@ -278,7 +292,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
}
/* Disable the TMC if need be */
- if (drvdata->enable)
+ if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
tmc_etb_disable_hw(drvdata);
drvdata->reading = true;
@@ -309,7 +323,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
}
/* 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
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c
b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 474c70c089f3..8bbbf3ab1387 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -85,6 +85,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
{
bool used = false;
+ long val;
unsigned long flags;
void __iomem *vaddr = NULL;
dma_addr_t paddr;
@@ -126,6 +127,15 @@ fast_path:
return -EBUSY;
}
+ 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 spin_unlock;
+
/*
* If drvdata::buf == NULL, use the memory allocated above.
* Otherwise a buffer still exists from a previous session, so
@@ -141,7 +151,7 @@ fast_path:
memset(drvdata->vaddr, 0, drvdata->size);
tmc_etr_enable_hw(drvdata);
- drvdata->enable = true;
+spin_unlock:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free memory outside the spinlock if need be */
@@ -154,6 +164,7 @@ fast_path:
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);
@@ -163,8 +174,11 @@ 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");
@@ -196,7 +210,7 @@ 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;
@@ -218,7 +232,7 @@ 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
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h
b/drivers/hwtracing/coresight/coresight-tmc.h
index df661903f83c..9b4c215d2b6b 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -99,7 +99,7 @@ enum tmc_mem_intf_width {
* @paddr: DMA start location in RAM.
* @vaddr: virtual representation of @paddr.
* @size: @buf size.
- * @enable: this TMC is being used.
+ * @mode: how this TMC is being used.
* @config_type: TMC variant, must be of type @tmc_config_type.
* @trigger_cntr: amount of words to store after a trigger.
*/
@@ -115,7 +115,7 @@ struct tmc_drvdata {
dma_addr_t paddr;
void __iomem *vaddr;
u32 size;
- bool enable;
+ local_t mode;
enum tmc_config_type config_type;
u32 trigger_cntr;
};
--
2.5.0
