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Commit a9bed610 authored by Tomas Winkler's avatar Tomas Winkler Committed by Greg Kroah-Hartman
Browse files

mei: allow read concurrency 



Replace clunky read state machine with read stack
implemented as per client read list, this is important
mostly for mei drivers with unsolicited reads

Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 928fa666

drivers/misc/mei/bus.c

+19 −17
Original line number Diff line number Diff line
@@ -288,19 +288,20 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length) 


	mutex_lock(&dev->device_lock);



	if (!cl->read_cb) {

	cb = mei_cl_read_cb(cl, NULL);

	if (cb)

		goto copy;



	rets = mei_cl_read_start(cl, length, NULL);

		if (rets < 0)

	if (rets && rets != -EBUSY)

		goto out;

	}



	if (cl->reading_state != MEI_READ_COMPLETE &&

	    !waitqueue_active(&cl->rx_wait)) {

	if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {



		mutex_unlock(&dev->device_lock);



		if (wait_event_interruptible(cl->rx_wait,

				cl->reading_state == MEI_READ_COMPLETE  ||

				(!list_empty(&cl->rd_completed)) ||

				mei_cl_is_transitioning(cl))) {



			if (signal_pending(current))
@@ -309,15 +310,20 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length) 
		}



		mutex_lock(&dev->device_lock);

	}



		if (mei_cl_is_transitioning(cl)) {

			rets = -EBUSY;

			goto out;

		}

	}



	if (cl->reading_state != MEI_READ_COMPLETE) {

	cb = mei_cl_read_cb(cl, NULL);

	if (!cb) {

		rets = 0;

		goto out;

	}



	cb = cl->read_cb;

copy:

	if (cb->status) {

		rets = cb->status;

		goto free;
@@ -329,9 +335,6 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length) 


free:

	mei_io_cb_free(cb);

	cl->read_cb = NULL;

	cl->reading_state = MEI_IDLE;



out:

	mutex_unlock(&dev->device_lock);
@@ -443,7 +446,7 @@ int mei_cl_enable_device(struct mei_cl_device *device) 


	mutex_unlock(&dev->device_lock);



	if (device->event_cb && !cl->read_cb)

	if (device->event_cb)

		mei_cl_read_start(device->cl, 0, NULL);



	if (!device->ops || !device->ops->enable)
@@ -485,8 +488,7 @@ int mei_cl_disable_device(struct mei_cl_device *device) 
	}



	/* Flush queues and remove any pending read */

	mei_cl_flush_queues(cl);

	mei_io_cb_free(cl->read_cb);

	mei_cl_flush_queues(cl, NULL);



	device->event_cb = NULL;

drivers/misc/mei/client.c

+54 −30
Original line number Diff line number Diff line
@@ -457,14 +457,56 @@ struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length, 
	return cb;

}



/**

 * mei_cl_read_cb - find this cl's callback in the read list

 *     for a specific file

 *

 * @cl: host client

 * @fp: file pointer (matching cb file object), may be NULL

 *

 * Return: cb on success, NULL if cb is not found

 */

struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)

{

	struct mei_cl_cb *cb;



	list_for_each_entry(cb, &cl->rd_completed, list)

		if (!fp || fp == cb->file_object)

			return cb;



	return NULL;

}



/**

 * mei_cl_read_cb_flush - free client's read pending and completed cbs

 *   for a specific file

 *

 * @cl: host client

 * @fp: file pointer (matching cb file object), may be NULL

 */

void mei_cl_read_cb_flush(const struct mei_cl *cl, const struct file *fp)

{

	struct mei_cl_cb *cb, *next;



	list_for_each_entry_safe(cb, next, &cl->rd_completed, list)

		if (!fp || fp == cb->file_object)

			mei_io_cb_free(cb);





	list_for_each_entry_safe(cb, next, &cl->rd_pending, list)

		if (!fp || fp == cb->file_object)

			mei_io_cb_free(cb);

}



/**

 * mei_cl_flush_queues - flushes queue lists belonging to cl.

 *

 * @cl: host client

 * @fp: file pointer (matching cb file object), may be NULL

 *

 * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.

 */

int mei_cl_flush_queues(struct mei_cl *cl)

int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)

{

	struct mei_device *dev;
@@ -474,13 +516,15 @@ int mei_cl_flush_queues(struct mei_cl *cl) 
	dev = cl->dev;



	cl_dbg(dev, cl, "remove list entry belonging to cl\n");

	mei_io_list_flush(&cl->dev->read_list, cl);

	mei_io_list_free(&cl->dev->write_list, cl);

	mei_io_list_free(&cl->dev->write_waiting_list, cl);

	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);

	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);

	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);

	mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);



	mei_cl_read_cb_flush(cl, fp);



	return 0;

}
@@ -497,9 +541,10 @@ void mei_cl_init(struct mei_cl *cl, struct mei_device *dev) 
	init_waitqueue_head(&cl->wait);

	init_waitqueue_head(&cl->rx_wait);

	init_waitqueue_head(&cl->tx_wait);

	INIT_LIST_HEAD(&cl->rd_completed);

	INIT_LIST_HEAD(&cl->rd_pending);

	INIT_LIST_HEAD(&cl->link);

	INIT_LIST_HEAD(&cl->device_link);

	cl->reading_state = MEI_IDLE;

	cl->writing_state = MEI_IDLE;

	cl->dev = dev;

}
@@ -523,24 +568,6 @@ struct mei_cl *mei_cl_allocate(struct mei_device *dev) 
	return cl;

}



/**

 * mei_cl_find_read_cb - find this cl's callback in the read list

 *

 * @cl: host client

 *

 * Return: cb on success, NULL on error

 */

struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl)

{

	struct mei_device *dev = cl->dev;

	struct mei_cl_cb *cb;



	list_for_each_entry(cb, &dev->read_list.list, list)

		if (mei_cl_cmp_id(cl, cb->cl))

			return cb;

	return NULL;

}



/**

 * mei_cl_link - allocate host id in the host map

 *
@@ -1006,10 +1033,10 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length, struct file *fp) 
	if (!mei_cl_is_connected(cl))

		return -ENODEV;



	if (cl->read_cb) {

		cl_dbg(dev, cl, "read is pending.\n");

	/* HW currently supports only one pending read */

	if (!list_empty(&cl->rd_pending))

		return -EBUSY;

	}



	me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id);

	if (!me_cl) {

		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
@@ -1036,13 +1063,11 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length, struct file *fp) 
		if (rets < 0)

			goto out;



		list_add_tail(&cb->list, &dev->read_list.list);

		list_add_tail(&cb->list, &cl->rd_pending);

	} else {

		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);

	}



	cl->read_cb = cb;



out:

	cl_dbg(dev, cl, "rpm: autosuspend\n");

	pm_runtime_mark_last_busy(dev->dev);
@@ -1268,9 +1293,8 @@ void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb) 
		if (waitqueue_active(&cl->tx_wait))

			wake_up_interruptible(&cl->tx_wait);



	} else if (cb->fop_type == MEI_FOP_READ &&

			MEI_READING == cl->reading_state) {

		cl->reading_state = MEI_READ_COMPLETE;

	} else if (cb->fop_type == MEI_FOP_READ) {

		list_add_tail(&cb->list, &cl->rd_completed);

		if (waitqueue_active(&cl->rx_wait))

			wake_up_interruptible(&cl->rx_wait);

		else

drivers/misc/mei/client.h

+4 −3
Original line number Diff line number Diff line
@@ -77,11 +77,12 @@ int mei_cl_unlink(struct mei_cl *cl); 


struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev, int id);



int mei_cl_flush_queues(struct mei_cl *cl);

struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl);



struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl,

				 const struct file *fp);

void mei_cl_read_cb_flush(const struct mei_cl *cl, const struct file *fp);

struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,

				  enum mei_cb_file_ops type, struct file *fp);

int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp);



int mei_cl_flow_ctrl_creds(struct mei_cl *cl);

drivers/misc/mei/debugfs.c

+1 −1
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ static ssize_t mei_dbgfs_read_active(struct file *fp, char __user *ubuf, 
		pos += scnprintf(buf + pos, bufsz - pos,

			"%2d|%2d|%4d|%5d|%2d|%2d|\n",

			i, cl->me_client_id, cl->host_client_id, cl->state,

			cl->reading_state, cl->writing_state);

			!list_empty(&cl->rd_completed), cl->writing_state);

		i++;

	}

out:

drivers/misc/mei/init.c

+0 −1
Original line number Diff line number Diff line
@@ -395,7 +395,6 @@ void mei_device_init(struct mei_device *dev, 
	dev->dev_state = MEI_DEV_INITIALIZING;

	dev->reset_count = 0;



	mei_io_list_init(&dev->read_list);

	mei_io_list_init(&dev->write_list);

	mei_io_list_init(&dev->write_waiting_list);

	mei_io_list_init(&dev->ctrl_wr_list);