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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: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Anup Patel 2017-08-22 15:27:02 +05:30 committed by Vinod Koul
parent fd8eb5395f
commit d6ffd2395a
1 changed files with 49 additions and 64 deletions
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113
drivers/dma/bcm-sba-raid.c
View File

@ -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++;
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;
/* 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;
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) {
@ -485,41 +477,34 @@ 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);
/* 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);
/* Mark request as received */
_sba_received_request(sba, first);
/* 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, req);
_sba_free_request(sba, first);
count--;
/* 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);
}
/* Process pending requests */
_sba_process_pending_requests(sba);
spin_unlock_irqrestore(&sba->reqs_lock, flags);
}
/* Re-check pending and completed work */
count = 0;
if (!list_empty(&sba->reqs_pending_list) ||
!list_empty(&sba->reqs_completed_list))
count = 1;
spin_unlock_irqrestore(&sba->reqs_lock, flags);
}
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);
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 ===== */