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Commit 8f9377dd authored by Mathieu Poirier's avatar Mathieu Poirier Committed by Yabin Cui
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UPSTREAM: coresight: etb10: Refactor etb_drvdata::mode handling 



(Upstream commit d43b8ec599f90c1f07b1bdd29b0c4b6306726ef2).

This patch moves the etb_drvdata::mode from a locat_t to a simple u32,
as it is for the ETF and ETR drivers.  This streamlines the code and adds
commonality with the other drivers when dealing with similar operations.

Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 140266694
Change-Id: I0f38579a632919a0eef37b9825a6cdf23a39b7cd
Signed-off-by: default avatarYabin Cui <yabinc@google.com>
parent 834cb9c8

drivers/hwtracing/coresight/coresight-etb10.c

+34 −28
Original line number Diff line number Diff line
@@ -5,7 +5,6 @@ 
 * Description: CoreSight Embedded Trace Buffer driver

 */



#include <asm/local.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/types.h>
@@ -72,8 +71,8 @@ 
 * @miscdev:	specifics to handle "/dev/xyz.etb" entry.

 * @spinlock:	only one at a time pls.

 * @reading:	synchronise user space access to etb buffer.

 * @mode:	this ETB is being used.

 * @buf:	area of memory where ETB buffer content gets sent.

 * @mode:	this ETB is being used.

 * @buffer_depth: size of @buf.

 * @trigger_cntr: amount of words to store after a trigger.

 */
@@ -85,8 +84,8 @@ struct etb_drvdata { 
	struct miscdevice	miscdev;

	spinlock_t		spinlock;

	local_t			reading;

	local_t			mode;

	u8			*buf;

	u32			mode;

	u32			buffer_depth;

	u32			trigger_cntr;

};
@@ -138,44 +137,48 @@ static void etb_enable_hw(struct etb_drvdata *drvdata) 
static int etb_enable(struct coresight_device *csdev, u32 mode, void *data)

{

	int ret = 0;

	u32 val;

	unsigned long flags;

	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);



	/*

	 * We don't have an internal state to clean up if we fail to setup

	 * the perf buffer. So we can perform the step before we turn the

	 * ETB on and leave without cleaning up.

	 */

	if (mode == CS_MODE_PERF) {

		ret = etb_set_buffer(csdev, (struct perf_output_handle *)data);

		if (ret)

			goto out;

	}

	spin_lock_irqsave(&drvdata->spinlock, flags);



	val = local_cmpxchg(&drvdata->mode,

			    CS_MODE_DISABLED, mode);

	/*

	 * When accessing from Perf, a HW buffer can be handled

	 * by a single trace entity.  In sysFS mode many tracers

	 * can be logging to the same HW buffer.

	 */

	if (val == CS_MODE_PERF)

		return -EBUSY;

	if (drvdata->mode == CS_MODE_PERF) {

		ret = -EBUSY;

		goto out;

	}



	/* Don't let perf disturb sysFS sessions */

	if (val == CS_MODE_SYSFS && mode == CS_MODE_PERF)

		return -EBUSY;

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

		ret = -EBUSY;

		goto out;

	}



	/* Nothing to do, the tracer is already enabled. */

	if (val == CS_MODE_SYSFS)

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

		goto out;



	spin_lock_irqsave(&drvdata->spinlock, flags);

	/*

	 * We don't have an internal state to clean up if we fail to setup

	 * the perf buffer. So we can perform the step before we turn the

	 * ETB on and leave without cleaning up.

	 */

	if (mode == CS_MODE_PERF) {

		ret = etb_set_buffer(csdev, (struct perf_output_handle *)data);

		if (ret)

			goto out;

	}



	drvdata->mode = mode;

	etb_enable_hw(drvdata);

	spin_unlock_irqrestore(&drvdata->spinlock, flags);



out:

	spin_unlock_irqrestore(&drvdata->spinlock, flags);



	if (!ret)

		dev_dbg(drvdata->dev, "ETB enabled\n");

	return ret;
@@ -277,12 +280,15 @@ static void etb_disable(struct coresight_device *csdev) 
	unsigned long flags;



	spin_lock_irqsave(&drvdata->spinlock, flags);



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

	if (drvdata->mode != CS_MODE_DISABLED) {

		etb_disable_hw(drvdata);

		etb_dump_hw(drvdata);

		drvdata->mode = CS_MODE_DISABLED;

	}

	spin_unlock_irqrestore(&drvdata->spinlock, flags);



	local_set(&drvdata->mode, CS_MODE_DISABLED);



	dev_dbg(drvdata->dev, "ETB disabled\n");

}
@@ -488,7 +494,7 @@ static void etb_dump(struct etb_drvdata *drvdata) 
	unsigned long flags;



	spin_lock_irqsave(&drvdata->spinlock, flags);

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

	if (drvdata->mode == CS_MODE_SYSFS) {

		etb_disable_hw(drvdata);

		etb_dump_hw(drvdata);

		etb_enable_hw(drvdata);