intel_th: msu: Make stopping the trace optional (8622dfef) · Commits · 戴 / test

Documentation/ABI/testing/sysfs-bus-intel_th-devices-msc

+8 −0

Original line number	Diff line number	Diff line
		@@ -40,3 +40,11 @@ Description: (RW) Trigger window switch for the MSC's buffer, in
		triggering a window switch for the buffer. Returns an error in any
		other operating mode or attempts to write something other than "1".

		What: /sys/bus/intel_th/devices/<intel_th_id>-msc<msc-id>/stop_on_full
		Date: March 2020
		KernelVersion: 5.7
		Contact: Alexander Shishkin <alexander.shishkin@linux.intel.com>
		Description: (RW) Configure whether trace stops when the last available window
		becomes full (1/y/Y) or wraps around and continues until the next
		window becomes available again (0/n/N).

drivers/hwtracing/intel_th/msu.c

+37 −1

Original line number	Diff line number	Diff line
		@@ -138,6 +138,7 @@ struct msc {
		struct list_head win_list;
		struct sg_table single_sgt;
		struct msc_window *cur_win;
		struct msc_window *switch_on_unlock;
		unsigned long nr_pages;
		unsigned long single_sz;
		unsigned int single_wrap : 1;
		@@ -154,6 +155,8 @@ struct msc {

		struct list_head iter_list;

		bool stop_on_full;

		/* config */
		unsigned int enabled : 1,
		wrap : 1,
		@@ -1718,6 +1721,10 @@ void intel_th_msc_window_unlock(struct device dev, struct sg_table sgt)
		return;

		msc_win_set_lockout(win, WIN_LOCKED, WIN_READY);
		if (msc->switch_on_unlock == win) {
		msc->switch_on_unlock = NULL;
		msc_win_switch(msc);
		}
		}
		EXPORT_SYMBOL_GPL(intel_th_msc_window_unlock);

		@@ -1758,7 +1765,11 @@ static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev)

		/* next window: if READY, proceed, if LOCKED, stop the trace */
		if (msc_win_set_lockout(next_win, WIN_READY, WIN_INUSE)) {
		if (msc->stop_on_full)
		schedule_work(&msc->work);
		else
		msc->switch_on_unlock = next_win;

		return IRQ_HANDLED;
		}

		@@ -2051,11 +2062,36 @@ win_switch_store(struct device dev, struct device_attribute attr,

		static DEVICE_ATTR_WO(win_switch);

		static ssize_t stop_on_full_show(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct msc *msc = dev_get_drvdata(dev);

		return sprintf(buf, "%d\n", msc->stop_on_full);
		}

		static ssize_t stop_on_full_store(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t size)
		{
		struct msc *msc = dev_get_drvdata(dev);
		int ret;

		ret = kstrtobool(buf, &msc->stop_on_full);
		if (ret)
		return ret;

		return size;
		}

		static DEVICE_ATTR_RW(stop_on_full);

		static struct attribute *msc_output_attrs[] = {
		&dev_attr_wrap.attr,
		&dev_attr_mode.attr,
		&dev_attr_nr_pages.attr,
		&dev_attr_win_switch.attr,
		&dev_attr_stop_on_full.attr,
		NULL,
		};

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