Commit d1376f3d authored by Alexander Usyskin's avatar Alexander Usyskin Committed by Greg Kroah-Hartman
Browse files

mei: add a spin lock to protect rd_completed queue 



In order to support vtags we need to access read completed
queue out of driver big lock.
Add a spin lock to protect rd_completed queue.

Signed-off-by: default avatarAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20200818115147.2567012-7-tomas.winkler@intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 74a9c967

drivers/misc/mei/bus.c

+3 −3
Original line number Diff line number Diff line
@@ -152,7 +152,7 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length, 
		if (timeout) {

			rets = wait_event_interruptible_timeout

					(cl->rx_wait,

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

					mei_cl_read_cb(cl, NULL) ||

					(!mei_cl_is_connected(cl)),

					msecs_to_jiffies(timeout));

			if (rets == 0)
@@ -165,7 +165,7 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length, 
		} else {

			if (wait_event_interruptible

					(cl->rx_wait,

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

					mei_cl_read_cb(cl, NULL) ||

					(!mei_cl_is_connected(cl)))) {

				if (signal_pending(current))

					return -EINTR;
@@ -198,7 +198,7 @@ copy: 
	rets = r_length;



free:

	mei_io_cb_free(cb);

	mei_cl_del_rd_completed(cl, cb);

out:

	mutex_unlock(&bus->device_lock);

drivers/misc/mei/client.c

+41 −6
Original line number Diff line number Diff line
@@ -507,15 +507,19 @@ struct mei_cl_cb *mei_cl_enqueue_ctrl_wr_cb(struct mei_cl *cl, size_t length, 
 *

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

{

	struct mei_cl_cb *cb;

	struct mei_cl_cb *ret_cb = NULL;



	spin_lock(&cl->rd_completed_lock);

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

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

			return cb;



	return NULL;

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

			ret_cb = cb;

			break;

		}

	spin_unlock(&cl->rd_completed_lock);

	return ret_cb;

}



/**
@@ -541,7 +545,9 @@ int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp) 
	mei_io_list_flush_cl(&cl->dev->ctrl_wr_list, cl);

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

	mei_io_list_free_fp(&cl->rd_pending, fp);

	spin_lock(&cl->rd_completed_lock);

	mei_io_list_free_fp(&cl->rd_completed, fp);

	spin_unlock(&cl->rd_completed_lock);



	return 0;

}
@@ -559,6 +565,7 @@ static void mei_cl_init(struct mei_cl *cl, struct mei_device *dev) 
	init_waitqueue_head(&cl->rx_wait);

	init_waitqueue_head(&cl->tx_wait);

	init_waitqueue_head(&cl->ev_wait);

	spin_lock_init(&cl->rd_completed_lock);

	INIT_LIST_HEAD(&cl->rd_completed);

	INIT_LIST_HEAD(&cl->rd_pending);

	INIT_LIST_HEAD(&cl->link);
@@ -1230,6 +1237,34 @@ static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl) 
	return 0;

}



/**

 * mei_cl_add_rd_completed - add read completed callback to list with lock

 *

 * @cl: host client

 * @cb: callback block

 *

 */

void mei_cl_add_rd_completed(struct mei_cl *cl, struct mei_cl_cb *cb)

{

	spin_lock(&cl->rd_completed_lock);

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

	spin_unlock(&cl->rd_completed_lock);

}



/**

 * mei_cl_del_rd_completed - free read completed callback with lock

 *

 * @cl: host client

 * @cb: callback block

 *

 */

void mei_cl_del_rd_completed(struct mei_cl *cl, struct mei_cl_cb *cb)

{

	spin_lock(&cl->rd_completed_lock);

	mei_io_cb_free(cb);

	spin_unlock(&cl->rd_completed_lock);

}



/**

 *  mei_cl_notify_fop2req - convert fop to proper request

 *
@@ -1897,7 +1932,7 @@ void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb) 
		break;



	case MEI_FOP_READ:

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

		mei_cl_add_rd_completed(cl, cb);

		if (!mei_cl_is_fixed_address(cl) &&

		    !WARN_ON(!cl->rx_flow_ctrl_creds))

			cl->rx_flow_ctrl_creds--;

drivers/misc/mei/client.h

+5 −2
Original line number Diff line number Diff line
@@ -133,8 +133,11 @@ int mei_cl_unlink(struct mei_cl *cl); 


struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev);



struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl,

				 const struct file *fp);

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



void mei_cl_add_rd_completed(struct mei_cl *cl, struct mei_cl_cb *cb);

void mei_cl_del_rd_completed(struct mei_cl *cl, struct mei_cl_cb *cb);



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

				  enum mei_cb_file_ops type,

				  const struct file *fp);

drivers/misc/mei/main.c

+3 −3
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ static ssize_t mei_read(struct file *file, char __user *ubuf, 


	mutex_unlock(&dev->device_lock);

	if (wait_event_interruptible(cl->rx_wait,

				     !list_empty(&cl->rd_completed) ||

				     mei_cl_read_cb(cl, file) ||

				     !mei_cl_is_connected(cl))) {

		if (signal_pending(current))

			return -EINTR;
@@ -229,7 +229,7 @@ copy_buffer: 
		goto out;



free:

	mei_io_cb_free(cb);

	mei_cl_del_rd_completed(cl, cb);

	*offset = 0;



out:
@@ -572,7 +572,7 @@ static __poll_t mei_poll(struct file *file, poll_table *wait) 
	if (req_events & (EPOLLIN | EPOLLRDNORM)) {

		poll_wait(file, &cl->rx_wait, wait);



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

		if (mei_cl_read_cb(cl, file))

			mask |= EPOLLIN | EPOLLRDNORM;

		else

			mei_cl_read_start(cl, mei_cl_mtu(cl), file);

drivers/misc/mei/mei_dev.h

+2 −0
Original line number Diff line number Diff line
@@ -217,6 +217,7 @@ struct mei_cl_cb { 
 * @tx_cb_queued: number of tx callbacks in queue

 * @writing_state: state of the tx

 * @rd_pending: pending read credits

 * @rd_completed_lock: protects rd_completed queue

 * @rd_completed: completed read

 *

 * @cldev: device on the mei client bus
@@ -242,6 +243,7 @@ struct mei_cl { 
	u8 tx_cb_queued;

	enum mei_file_transaction_states writing_state;

	struct list_head rd_pending;

	spinlock_t rd_completed_lock; /* protects rd_completed queue */

	struct list_head rd_completed;



	struct mei_cl_device *cldev;

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