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Message-Id: <1461708634-6327-12-git-send-email-mathieu.poirier@linaro.org>
Date: Tue, 26 Apr 2016 16:10:27 -0600
From: Mathieu Poirier <mathieu.poirier@...aro.org>
To: linux-arm-kernel@...ts.infradead.org, Suzuki.Poulose@....com
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH V4 11/18] 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@...aro.org>
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 27 ++++++++++++++++++-------
drivers/hwtracing/coresight/coresight-tmc-etr.c | 23 ++++++++++++++++-----
drivers/hwtracing/coresight/coresight-tmc.h | 4 ++--
3 files changed, 40 insertions(+), 14 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 60edf4d1968f..bc0efc1e5b49 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -111,6 +111,7 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
int ret = 0;
bool used = false;
char *buf = NULL;
+ long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -140,6 +141,15 @@ static int tmc_enable_etf_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 isn't NULL, memory was allocated for a previous
* trace run but wasn't read. If so simply zero-out the memory.
@@ -157,7 +167,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
}
tmc_etb_enable_hw(drvdata);
- drvdata->enable = true;
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -173,6 +182,7 @@ out:
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);
@@ -182,8 +192,11 @@ 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");
@@ -202,7 +215,7 @@ 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");
@@ -222,7 +235,7 @@ 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");
@@ -279,7 +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;
@@ -310,7 +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 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
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 592eb149fe3a..94bc034d3b98 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -98,7 +98,7 @@ 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.
*/
@@ -113,7 +113,7 @@ 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
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