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authorAlexander Shishkin <alexander.shishkin@linux.intel.com>2019-05-03 11:44:50 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-03 18:17:40 +0200
commit6cac7866c27418cd784fbb8041c2dddd6d966bc7 (patch)
tree1d6470e54a77ac654b05728552953a8317413c6e /drivers/hwtracing
parent4840572d3d7e66d7b55d3fc3b0f52711fd172eb8 (diff)
downloadlinux-6cac7866c27418cd784fbb8041c2dddd6d966bc7.tar.gz
intel_th: msu: Add a sysfs attribute to trigger window switch
Now that we have the means to trigger a window switch for the MSU trace
store, add a sysfs file to allow triggering it from userspace.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/intel_th/msu.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index b0bb69942328..aed72b33675d 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -1572,10 +1572,38 @@ free_win:
 
 static DEVICE_ATTR_RW(nr_pages);
 
+static ssize_t
+win_switch_store(struct device *dev, struct device_attribute *attr,
+		 const char *buf, size_t size)
+{
+	struct msc *msc = dev_get_drvdata(dev);
+	unsigned long val;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	if (val != 1)
+		return -EINVAL;
+
+	mutex_lock(&msc->buf_mutex);
+	if (msc->mode != MSC_MODE_MULTI)
+		ret = -ENOTSUPP;
+	else
+		ret = intel_th_trace_switch(msc->thdev);
+	mutex_unlock(&msc->buf_mutex);
+
+	return ret ? ret : size;
+}
+
+static DEVICE_ATTR_WO(win_switch);
+
 static struct attribute *msc_output_attrs[] = {
 	&dev_attr_wrap.attr,
 	&dev_attr_mode.attr,
 	&dev_attr_nr_pages.attr,
+	&dev_attr_win_switch.attr,
 	NULL,
 };