Commit 5a731aeb authored by Cristian Marussi's avatar Cristian Marussi Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Refactor message response path 

Refactor code path waiting for message responses into a dedicated helper
function.

No functional change.

Link: https://lore.kernel.org/r/20211129191156.29322-4-cristian.marussi@arm.com


Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent 582730b9

drivers/firmware/arm_scmi/driver.c

+56 −32
Original line number Diff line number Diff line
@@ -738,6 +738,61 @@ static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, 
	       ktime_after(ktime_get(), stop);

}



/**

 * scmi_wait_for_message_response  - An helper to group all the possible ways of

 * waiting for a synchronous message response.

 *

 * @cinfo: SCMI channel info

 * @xfer: Reference to the transfer being waited for.

 *

 * Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on

 * configuration flags like xfer->hdr.poll_completion.

 *

 * Return: 0 on Success, error otherwise.

 */

static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,

					  struct scmi_xfer *xfer)

{

	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);

	struct device *dev = info->dev;

	int ret = 0, timeout_ms = info->desc->max_rx_timeout_ms;



	if (xfer->hdr.poll_completion) {

		ktime_t stop = ktime_add_ms(ktime_get(), timeout_ms);



		spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));

		if (ktime_before(ktime_get(), stop)) {

			unsigned long flags;



			/*

			 * Do not fetch_response if an out-of-order delayed

			 * response is being processed.

			 */

			spin_lock_irqsave(&xfer->lock, flags);

			if (xfer->state == SCMI_XFER_SENT_OK) {

				info->desc->ops->fetch_response(cinfo, xfer);

				xfer->state = SCMI_XFER_RESP_OK;

			}

			spin_unlock_irqrestore(&xfer->lock, flags);

		} else {

			dev_err(dev,

				"timed out in resp(caller: %pS) - polling\n",

				(void *)_RET_IP_);

			ret = -ETIMEDOUT;

		}

	} else {

		/* And we wait for the response. */

		if (!wait_for_completion_timeout(&xfer->done,

						 msecs_to_jiffies(timeout_ms))) {

			dev_err(dev, "timed out in resp(caller: %pS)\n",

				(void *)_RET_IP_);

			ret = -ETIMEDOUT;

		}

	}



	return ret;

}



/**

 * do_xfer() - Do one transfer

 *
@@ -752,7 +807,6 @@ static int do_xfer(const struct scmi_protocol_handle *ph, 
		   struct scmi_xfer *xfer)

{

	int ret;

	int timeout;

	const struct scmi_protocol_instance *pi = ph_to_pi(ph);

	struct scmi_info *info = handle_to_scmi_info(pi->handle);

	struct device *dev = info->dev;
@@ -796,37 +850,7 @@ static int do_xfer(const struct scmi_protocol_handle *ph, 
		return ret;

	}



	if (xfer->hdr.poll_completion) {

		ktime_t stop = ktime_add_ms(ktime_get(),

					    info->desc->max_rx_timeout_ms);



		spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));

		if (ktime_before(ktime_get(), stop)) {

			unsigned long flags;



			/*

			 * Do not fetch_response if an out-of-order delayed

			 * response is being processed.

			 */

			spin_lock_irqsave(&xfer->lock, flags);

			if (xfer->state == SCMI_XFER_SENT_OK) {

				info->desc->ops->fetch_response(cinfo, xfer);

				xfer->state = SCMI_XFER_RESP_OK;

			}

			spin_unlock_irqrestore(&xfer->lock, flags);

		} else {

			ret = -ETIMEDOUT;

		}

	} else {

		/* And we wait for the response. */

		timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);

		if (!wait_for_completion_timeout(&xfer->done, timeout)) {

			dev_err(dev, "timed out in resp(caller: %pS)\n",

				(void *)_RET_IP_);

			ret = -ETIMEDOUT;

		}

	}



	ret = scmi_wait_for_message_response(cinfo, xfer);

	if (!ret && xfer->hdr.status)

		ret = scmi_to_linux_errno(xfer->hdr.status);