Commit d6ffd239 authored by Anup Patel's avatar Anup Patel Committed by Vinod Koul
Browse files

dmaengine: bcm-sba-raid: Re-factor sba_process_deferred_requests() 



Currently, sba_process_deferred_requests() handles both pending
and completed sba_request which is unnecessary overhead for
sba_issue_pending() because completed sba_request handling is
not required in sba_issue_pending().

This patch breaks sba_process_deferred_requests() into two parts
sba_process_received_request() and _sba_process_pending_requests().

The sba_issue_pending() will only process pending sba_request
by calling _sba_process_pending_requests(). This will improve
sba_issue_pending().

The sba_receive_message() will only process received sba_request
by calling sba_process_received_request() for each received
sba_request. The sba_process_received_request() will also call
_sba_process_pending_requests() after handling received sba_request
because we might have pending sba_request not submitted by previous
call to sba_issue_pending().

Signed-off-by: default avatarAnup Patel <anup.patel@broadcom.com>
Reviewed-by: default avatarScott Branden <scott.branden@broadcom.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent fd8eb539

drivers/dma/bcm-sba-raid.c

+47 −62
Original line number Diff line number Diff line
@@ -419,22 +419,20 @@ static int sba_send_mbox_request(struct sba_device *sba, 
	return 0;

}



static void sba_process_deferred_requests(struct sba_device *sba)

/* Note: Must be called with sba->reqs_lock held */

static void _sba_process_pending_requests(struct sba_device *sba)

{

	int ret;

	u32 count;

	unsigned long flags;

	struct sba_request *req;

	struct dma_async_tx_descriptor *tx;



	spin_lock_irqsave(&sba->reqs_lock, flags);



	/* Count pending requests */

	count = 0;

	list_for_each_entry(req, &sba->reqs_pending_list, node)

		count++;



	/* Process pending requests */

	/*

	 * Process few pending requests

	 *

	 * For now, we process (<number_of_mailbox_channels> * 8)

	 * number of requests at a time.

	 */

	count = sba->mchans_count * 8;

	while (!list_empty(&sba->reqs_pending_list) && count) {

		/* Get the first pending request */

		req = list_first_entry(&sba->reqs_pending_list,
@@ -445,11 +443,7 @@ static void sba_process_deferred_requests(struct sba_device *sba) 
			break;



		/* Send request to mailbox channel */

		spin_unlock_irqrestore(&sba->reqs_lock, flags);

		ret = sba_send_mbox_request(sba, req);

		spin_lock_irqsave(&sba->reqs_lock, flags);



		/* If something went wrong then keep request pending */

		if (ret < 0) {

			_sba_pending_request(sba, req);

			break;
@@ -457,20 +451,18 @@ static void sba_process_deferred_requests(struct sba_device *sba) 


		count--;

	}

}



	/* Count completed requests */

	count = 0;

	list_for_each_entry(req, &sba->reqs_completed_list, node)

		count++;



	/* Process completed requests */

	while (!list_empty(&sba->reqs_completed_list) && count) {

		req = list_first_entry(&sba->reqs_completed_list,

					struct sba_request, node);

		list_del_init(&req->node);

		tx = &req->tx;

static void sba_process_received_request(struct sba_device *sba,

					 struct sba_request *req)

{

	unsigned long flags;

	struct dma_async_tx_descriptor *tx;

	struct sba_request *nreq, *first = req->first;



		spin_unlock_irqrestore(&sba->reqs_lock, flags);

	/* Process only after all chained requests are received */

	if (!atomic_dec_return(&first->next_pending_count)) {

		tx = &first->tx;



		WARN_ON(tx->cookie < 0);

		if (tx->cookie > 0) {
@@ -485,42 +477,35 @@ static void sba_process_deferred_requests(struct sba_device *sba) 


		spin_lock_irqsave(&sba->reqs_lock, flags);



		/* If waiting for 'ack' then move to completed list */

		if (!async_tx_test_ack(&req->tx))

			_sba_complete_request(sba, req);

		else

			_sba_free_request(sba, req);

		/* Free all requests chained to first request */

		list_for_each_entry(nreq, &first->next, next)

			_sba_free_request(sba, nreq);

		INIT_LIST_HEAD(&first->next);



		count--;

	}

		/* Mark request as received */

		_sba_received_request(sba, first);



	/* Re-check pending and completed work */

	count = 0;

	if (!list_empty(&sba->reqs_pending_list) ||

	    !list_empty(&sba->reqs_completed_list))

		count = 1;

		/* The client is allowed to attach dependent operations

		 * until 'ack' is set

		 */

		if (!async_tx_test_ack(tx))

			_sba_complete_request(sba, first);

		else

			_sba_free_request(sba, first);



	spin_unlock_irqrestore(&sba->reqs_lock, flags);

		/* Cleanup completed requests */

		list_for_each_entry_safe(req, nreq,

					 &sba->reqs_completed_list, node) {

			if (async_tx_test_ack(&req->tx))

				_sba_free_request(sba, req);

		}



static void sba_process_received_request(struct sba_device *sba,

					 struct sba_request *req)

{

	unsigned long flags;



	spin_lock_irqsave(&sba->reqs_lock, flags);



	/* Mark request as received */

	_sba_received_request(sba, req);



	/* Update request */

	if (!atomic_dec_return(&req->first->next_pending_count))

		_sba_complete_request(sba, req->first);

	if (req->first != req)

		_sba_free_request(sba, req);

		/* Process pending requests */

		_sba_process_pending_requests(sba);



		spin_unlock_irqrestore(&sba->reqs_lock, flags);

	}

}



/* ====== DMAENGINE callbacks ===== */
@@ -544,10 +529,13 @@ static int sba_device_terminate_all(struct dma_chan *dchan) 


static void sba_issue_pending(struct dma_chan *dchan)

{

	unsigned long flags;

	struct sba_device *sba = to_sba_device(dchan);



	/* Process deferred requests */

	sba_process_deferred_requests(sba);

	/* Process pending requests */

	spin_lock_irqsave(&sba->reqs_lock, flags);

	_sba_process_pending_requests(sba);

	spin_unlock_irqrestore(&sba->reqs_lock, flags);

}



static dma_cookie_t sba_tx_submit(struct dma_async_tx_descriptor *tx)
@@ -1482,9 +1470,6 @@ static void sba_receive_message(struct mbox_client *cl, void *msg) 


	/* Process received request */

	sba_process_received_request(sba, req);



	/* Process deferred requests */

	sba_process_deferred_requests(sba);

}



/* ====== Platform driver routines ===== */

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