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Commit 60ae1e4c authored by Pratik Patel's avatar Pratik Patel Committed by Shashank Mittal
Browse files

coresight-etm4x: Controls pertaining to the selection of resources 



Adding sysfs entries to control the selection of the resources the
trace unit will use as triggers to perform a trace run.

Change-Id: I61ed89e7e87b4b8dad5fa3d9adb9c1d0451864d6
Signed-off-by: default avatarPratik Patel <pratikp@codeaurora.org>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 6afa8a1387aa4af73e8c3b81019d958ef8a2a4d0
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: default avatarShashank Mittal <mittals@codeaurora.org>
parent 9cf2c224

Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x

+12 −0
Original line number Diff line number Diff line
@@ -230,3 +230,15 @@ Date: April 2015 
KernelVersion:	4.01

Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>

Description: 	(RW) Controls the operation of the selected counter.



What:		/sys/bus/coresight/devices/<memory_map>.etm/res_idx

Date:		April 2015

KernelVersion:	4.01

Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>

Description: 	(RW) Select which resource selection unit to work with.



What:		/sys/bus/coresight/devices/<memory_map>.etm/res_ctrl

Date:		April 2015

KernelVersion:	4.01

Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>

Description: 	(RW) Controls the selection of the resources in the trace unit.

drivers/hwtracing/coresight/coresight-etm4x.c

+75 −0
Original line number Diff line number Diff line
@@ -1707,6 +1707,79 @@ static ssize_t cntr_ctrl_store(struct device *dev, 
}

static DEVICE_ATTR_RW(cntr_ctrl);



static ssize_t res_idx_show(struct device *dev,

			    struct device_attribute *attr,

			    char *buf)

{

	unsigned long val;

	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);



	val = drvdata->res_idx;

	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);

}



static ssize_t res_idx_store(struct device *dev,

			     struct device_attribute *attr,

			     const char *buf, size_t size)

{

	unsigned long val;

	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);



	if (kstrtoul(buf, 16, &val))

		return -EINVAL;

	/* Resource selector pair 0 is always implemented and reserved */

	if ((val == 0) || (val >= drvdata->nr_resource))

		return -EINVAL;



	/*

	 * Use spinlock to ensure index doesn't change while it gets

	 * dereferenced multiple times within a spinlock block elsewhere.

	 */

	spin_lock(&drvdata->spinlock);

	drvdata->res_idx = val;

	spin_unlock(&drvdata->spinlock);

	return size;

}

static DEVICE_ATTR_RW(res_idx);



static ssize_t res_ctrl_show(struct device *dev,

			     struct device_attribute *attr,

			     char *buf)

{

	u8 idx;

	unsigned long val;

	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);



	spin_lock(&drvdata->spinlock);

	idx = drvdata->res_idx;

	val = drvdata->res_ctrl[idx];

	spin_unlock(&drvdata->spinlock);

	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);

}



static ssize_t res_ctrl_store(struct device *dev,

			      struct device_attribute *attr,

			      const char *buf, size_t size)

{

	u8 idx;

	unsigned long val;

	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);



	if (kstrtoul(buf, 16, &val))

		return -EINVAL;



	spin_lock(&drvdata->spinlock);

	idx = drvdata->res_idx;

	/* For odd idx pair inversal bit is RES0 */

	if (idx % 2 != 0)

		/* PAIRINV, bit[21] */

		val &= ~BIT(21);

	drvdata->res_ctrl[idx] = val;

	spin_unlock(&drvdata->spinlock);

	return size;

}

static DEVICE_ATTR_RW(res_ctrl);



static ssize_t cpu_show(struct device *dev,

			struct device_attribute *attr, char *buf)

{
@@ -1757,6 +1830,8 @@ static struct attribute *coresight_etmv4_attrs[] = { 
	&dev_attr_cntrldvr.attr,

	&dev_attr_cntr_val.attr,

	&dev_attr_cntr_ctrl.attr,

	&dev_attr_res_idx.attr,

	&dev_attr_res_ctrl.attr,

	&dev_attr_cpu.attr,

	NULL,

};