[PATCH 4/6] dma: bcm-sba-raid: Break sba_process_deferred_requests() into two parts
Anup Patel
anup.patel at broadcom.com
Tue Jul 25 22:36:42 PDT 2017
This patch breaks sba_process_deferred_requests() into two parts
sba_process_received_request() and _sba_process_pending_requests()
for readability.
In addition, we remove redundant SBA_REQUEST_STATE_RECEIVED state
and ensure that all requests in a chained request should be freed
only after all have been received.
Signed-off-by: Anup Patel <anup.patel at broadcom.com>
Reviewed-by: Scott Branden <scott.branden at broadcom.com>
---
drivers/dma/bcm-sba-raid.c | 130 ++++++++++++++++-----------------------------
1 file changed, 47 insertions(+), 83 deletions(-)
diff --git a/drivers/dma/bcm-sba-raid.c b/drivers/dma/bcm-sba-raid.c
index db5e3db..b92c756 100644
--- a/drivers/dma/bcm-sba-raid.c
+++ b/drivers/dma/bcm-sba-raid.c
@@ -97,9 +97,8 @@ enum sba_request_flags {
SBA_REQUEST_STATE_ALLOCED = 0x002,
SBA_REQUEST_STATE_PENDING = 0x004,
SBA_REQUEST_STATE_ACTIVE = 0x008,
- SBA_REQUEST_STATE_RECEIVED = 0x010,
- SBA_REQUEST_STATE_COMPLETED = 0x020,
- SBA_REQUEST_STATE_ABORTED = 0x040,
+ SBA_REQUEST_STATE_COMPLETED = 0x010,
+ SBA_REQUEST_STATE_ABORTED = 0x020,
SBA_REQUEST_STATE_MASK = 0x0ff,
SBA_REQUEST_FENCE = 0x100,
};
@@ -159,7 +158,6 @@ struct sba_device {
struct list_head reqs_alloc_list;
struct list_head reqs_pending_list;
struct list_head reqs_active_list;
- struct list_head reqs_received_list;
struct list_head reqs_completed_list;
struct list_head reqs_aborted_list;
struct list_head reqs_free_list;
@@ -306,17 +304,6 @@ static void _sba_complete_request(struct sba_device *sba,
sba->reqs_fence = false;
}
-/* Note: Must be called with sba->reqs_lock held */
-static void _sba_received_request(struct sba_device *sba,
- struct sba_request *req)
-{
- lockdep_assert_held(&sba->reqs_lock);
- req->flags = SBA_REQUEST_STATE_RECEIVED;
- list_move_tail(&req->node, &sba->reqs_received_list);
- if (list_empty(&sba->reqs_active_list))
- sba->reqs_fence = false;
-}
-
static void sba_free_chained_requests(struct sba_request *req)
{
unsigned long flags;
@@ -358,10 +345,6 @@ static void sba_cleanup_nonpending_requests(struct sba_device *sba)
list_for_each_entry_safe(req, req1, &sba->reqs_alloc_list, node)
_sba_free_request(sba, req);
- /* Freeup all received request */
- list_for_each_entry_safe(req, req1, &sba->reqs_received_list, node)
- _sba_free_request(sba, req);
-
/* Freeup all completed request */
list_for_each_entry_safe(req, req1, &sba->reqs_completed_list, node)
_sba_free_request(sba, req);
@@ -417,22 +400,20 @@ 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,
@@ -443,11 +424,7 @@ 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;
@@ -455,20 +432,18 @@ 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) {
@@ -483,41 +458,31 @@ 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);
-
- count--;
- }
-
- /* 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;
+ /* 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);
- spin_lock_irqsave(&sba->reqs_lock, flags);
+ /* 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);
- /* Mark request as received */
- _sba_received_request(sba, req);
+ /* 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);
+ }
- /* 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);
+ spin_unlock_irqrestore(&sba->reqs_lock, flags);
+ }
}
/* ====== DMAENGINE callbacks ===== */
@@ -542,10 +507,13 @@ 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)
@@ -1480,9 +1448,6 @@ 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 ===== */
@@ -1511,7 +1476,6 @@ static int sba_prealloc_channel_resources(struct sba_device *sba)
INIT_LIST_HEAD(&sba->reqs_alloc_list);
INIT_LIST_HEAD(&sba->reqs_pending_list);
INIT_LIST_HEAD(&sba->reqs_active_list);
- INIT_LIST_HEAD(&sba->reqs_received_list);
INIT_LIST_HEAD(&sba->reqs_completed_list);
INIT_LIST_HEAD(&sba->reqs_aborted_list);
INIT_LIST_HEAD(&sba->reqs_free_list);
--
2.7.4
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