Commit 297ab90f authored by Suzuki K. Poulose's avatar Suzuki K. Poulose Committed by Greg Kroah-Hartman
Browse files

coresight: tmc: Cleanup operation mode handling 

The mode of operation of the TMC tracked in drvdata->mode is defined
as a local_t type. This is always checked and modified under the
drvdata->spinlock and hence we don't need local_t for it and the
unnecessary synchronisation instructions that comes with it. This
change makes the code a bit more cleaner.

Also fixes the order in which we update the drvdata->mode to
CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
which in turn depends on the mode to decide whether to dump the
trace to a buffer.

Applies on mathieu's coresight/next tree [1]

https://git.linaro.org/kernel/coresight.git

 next

Reported-by: default avatarVenkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d52c9750

drivers/hwtracing/coresight/coresight-tmc-etf.c

+14 −18
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata) 
	 * When operating in sysFS mode the content of the buffer needs to be

	 * read before the TMC is disabled.

	 */

	if (local_read(&drvdata->mode) == CS_MODE_SYSFS)

	if (drvdata->mode == CS_MODE_SYSFS)

		tmc_etb_dump_hw(drvdata);

	tmc_disable_hw(drvdata);
@@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(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);
@@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(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)

	if (drvdata->mode == CS_MODE_SYSFS)

		goto out;



	/*
@@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode) 
		drvdata->buf = buf;

	}



	drvdata->mode = CS_MODE_SYSFS;

	tmc_etb_enable_hw(drvdata);

out:

	spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -180,7 +179,6 @@ out: 
static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)

{

	int ret = 0;

	long val;

	unsigned long flags;

	struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode) 
		goto out;

	}



	val = local_xchg(&drvdata->mode, 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) {

	if (drvdata->mode != CS_MODE_DISABLED) {

		ret = -EINVAL;

		goto out;

	}



	drvdata->mode = mode;

	tmc_etb_enable_hw(drvdata);

out:

	spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode) 


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);
@@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev) 
		return;

	}



	val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);

	/* Disable the TMC only if it needs to */

	if (val != CS_MODE_DISABLED)

	if (drvdata->mode != CS_MODE_DISABLED) {

		tmc_etb_disable_hw(drvdata);

		drvdata->mode = CS_MODE_DISABLED;

	}



	spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev, 
	}



	tmc_etf_enable_hw(drvdata);

	local_set(&drvdata->mode, CS_MODE_SYSFS);

	drvdata->mode = CS_MODE_SYSFS;

	spin_unlock_irqrestore(&drvdata->spinlock, flags);



	dev_info(drvdata->dev, "TMC-ETF enabled\n");
@@ -280,7 +278,7 @@ static void tmc_disable_etf_link(struct coresight_device *csdev, 
	}



	tmc_etf_disable_hw(drvdata);

	local_set(&drvdata->mode, CS_MODE_DISABLED);

	drvdata->mode = CS_MODE_DISABLED;

	spin_unlock_irqrestore(&drvdata->spinlock, flags);



	dev_info(drvdata->dev, "TMC disabled\n");
@@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev, 
		return;



	/* This shouldn't happen */

	if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF))

	if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))

		return;



	CS_UNLOCK(drvdata->base);
@@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = { 


int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)

{

	long val;

	enum tmc_mode mode;

	int ret = 0;

	unsigned long flags;
@@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) 
		goto out;

	}



	val = local_read(&drvdata->mode);

	/* Don't interfere if operated from Perf */

	if (val == CS_MODE_PERF) {

	if (drvdata->mode == CS_MODE_PERF) {

		ret = -EINVAL;

		goto out;

	}
@@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) 
	}



	/* Disable the TMC if need be */

	if (val == CS_MODE_SYSFS)

	if (drvdata->mode == CS_MODE_SYSFS)

		tmc_etb_disable_hw(drvdata);



	drvdata->reading = true;
@@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) 
	}



	/* Re-enable the TMC if need be */

	if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {

	if (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

drivers/hwtracing/coresight/coresight-tmc-etr.c

+11 −15
Original line number Diff line number Diff line
@@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) 
	 * When operating in sysFS mode the content of the buffer needs to be

	 * read before the TMC is disabled.

	 */

	if (local_read(&drvdata->mode) == CS_MODE_SYSFS)

	if (drvdata->mode == CS_MODE_SYSFS)

		tmc_etr_dump_hw(drvdata);

	tmc_disable_hw(drvdata);
@@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(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;
@@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(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)

	if (drvdata->mode == CS_MODE_SYSFS)

		goto out;



	/*
@@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode) 


	memset(drvdata->vaddr, 0, drvdata->size);



	drvdata->mode = CS_MODE_SYSFS;

	tmc_etr_enable_hw(drvdata);

out:

	spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -174,7 +173,6 @@ out: 
static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)

{

	int ret = 0;

	long val;

	unsigned long flags;

	struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -188,17 +186,17 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode) 
		goto out;

	}



	val = local_xchg(&drvdata->mode, 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) {

	if (drvdata->mode != CS_MODE_DISABLED) {

		ret = -EINVAL;

		goto out;

	}



	drvdata->mode = CS_MODE_PERF;

	tmc_etr_enable_hw(drvdata);

out:

	spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode) 


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);
@@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev) 
		return;

	}



	val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);

	/* Disable the TMC only if it needs to */

	if (val != CS_MODE_DISABLED)

	if (drvdata->mode != CS_MODE_DISABLED) {

		tmc_etr_disable_hw(drvdata);

		drvdata->mode = CS_MODE_DISABLED;

	}



	spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = { 
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)

{

	int ret = 0;

	long val;

	unsigned long flags;



	/* config types are set a boot time and never change */
@@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) 
		goto out;

	}



	val = local_read(&drvdata->mode);

	/* Don't interfere if operated from Perf */

	if (val == CS_MODE_PERF) {

	if (drvdata->mode == CS_MODE_PERF) {

		ret = -EINVAL;

		goto out;

	}
@@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) 
	}



	/* Disable the TMC if need be */

	if (val == CS_MODE_SYSFS)

	if (drvdata->mode == CS_MODE_SYSFS)

		tmc_etr_disable_hw(drvdata);



	drvdata->reading = true;
@@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) 
	spin_lock_irqsave(&drvdata->spinlock, flags);



	/* RE-enable the TMC if need be */

	if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {

	if (drvdata->mode == CS_MODE_SYSFS) {

		/*

		 * The trace run will continue with the same allocated trace

		 * buffer. The trace buffer is cleared in tmc_etr_enable_hw(),

drivers/hwtracing/coresight/coresight-tmc.h

+1 −1
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ struct tmc_drvdata { 
	void __iomem		*vaddr;

	u32			size;

	u32			len;

	local_t			mode;

	u32			mode;

	enum tmc_config_type	config_type;

	enum tmc_mem_intf_width	memwidth;

	u32			trigger_cntr;

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