dmaengine: bcm-sba-raid: Remove redundant SBA_REQUEST_STATE_COMPLETED

The SBA_REQUEST_STATE_COMPLETED state was added to keep track
of sba_request which got completed but cannot be freed because
underlying Async Tx descriptor was not ACKed by DMA client.

Instead of above, we can free the sba_request with non-ACKed
Async Tx descriptor and sba_alloc_request() will ensure that
it always allocates sba_request with ACKed Async Tx descriptor.
This alternate approach makes SBA_REQUEST_STATE_COMPLETED state
redundant hence this patch removes it.

Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 17 insertions, 46 deletions

diff --git a/drivers/dma/bcm-sba-raid.c b/drivers/dma/bcm-sba-raid.c
index c3643d30e31b..6c2c44724637 100644
--- a/drivers/dma/bcm-sba-raid.c
+++ b/drivers/dma/bcm-sba-raid.c
@@ -99,8 +99,7 @@ enum sba_request_flags {
         SBA_REQUEST_STATE_ALLOCED       = 0x002,
         SBA_REQUEST_STATE_PENDING       = 0x004,
         SBA_REQUEST_STATE_ACTIVE        = 0x008,
-        SBA_REQUEST_STATE_COMPLETED     = 0x010,
-        SBA_REQUEST_STATE_ABORTED       = 0x020,
+        SBA_REQUEST_STATE_ABORTED       = 0x010,
         SBA_REQUEST_STATE_MASK          = 0x0ff,
         SBA_REQUEST_FENCE               = 0x100,
 };
@@ -160,7 +159,6 @@ 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_completed_list;
         struct list_head reqs_aborted_list;
         struct list_head reqs_free_list;
         /* DebugFS directory entries */
@@ -212,17 +210,21 @@ static void sba_peek_mchans(struct sba_device *sba)
 
 static struct sba_request *sba_alloc_request(struct sba_device *sba)
 {
+        bool found = false;
         unsigned long flags;
         struct sba_request *req = NULL;
 
         spin_lock_irqsave(&sba->reqs_lock, flags);
-        req = list_first_entry_or_null(&sba->reqs_free_list,
-                                       struct sba_request, node);
-        if (req)
-                list_move_tail(&req->node, &sba->reqs_alloc_list);
+        list_for_each_entry(req, &sba->reqs_free_list, node) {
+                if (async_tx_test_ack(&req->tx)) {
+                        list_move_tail(&req->node, &sba->reqs_alloc_list);
+                        found = true;
+                        break;
+                }
+        }
         spin_unlock_irqrestore(&sba->reqs_lock, flags);
 
-        if (!req) {
+        if (!found) {
                 /*
                  * We have no more free requests so, we peek
                  * mailbox channels hoping few active requests
@@ -297,18 +299,6 @@ static void _sba_free_request(struct sba_device *sba,
                 sba->reqs_fence = false;
 }
 
-/* Note: Must be called with sba->reqs_lock held */
-static void _sba_complete_request(struct sba_device *sba,
-                                  struct sba_request *req)
-{
-        lockdep_assert_held(&sba->reqs_lock);
-        req->flags &= ~SBA_REQUEST_STATE_MASK;
-        req->flags |= SBA_REQUEST_STATE_COMPLETED;
-        list_move_tail(&req->node, &sba->reqs_completed_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;
@@ -350,10 +340,6 @@ 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 completed request */
-        list_for_each_entry_safe(req, req1, &sba->reqs_completed_list, node)
-                _sba_free_request(sba, req);
-
         /* Set all active requests as aborted */
         list_for_each_entry_safe(req, req1, &sba->reqs_active_list, node)
                 _sba_abort_request(sba, req);
@@ -472,20 +458,8 @@ static void sba_process_received_request(struct sba_device *sba,
                         _sba_free_request(sba, nreq);
                 INIT_LIST_HEAD(&first->next);
 
-                /* 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);
-
-                /* 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);
-                }
+                /* Free the first request */
+                _sba_free_request(sba, first);
 
                 /* Process pending requests */
                 _sba_process_pending_requests(sba);
@@ -499,13 +473,14 @@ static void sba_write_stats_in_seqfile(struct sba_device *sba,
 {
         unsigned long flags;
         struct sba_request *req;
-        u32 free_count = 0, alloced_count = 0, pending_count = 0;
-        u32 active_count = 0, aborted_count = 0, completed_count = 0;
+        u32 free_count = 0, alloced_count = 0;
+        u32 pending_count = 0, active_count = 0, aborted_count = 0;
 
         spin_lock_irqsave(&sba->reqs_lock, flags);
 
         list_for_each_entry(req, &sba->reqs_free_list, node)
-                free_count++;
+                if (async_tx_test_ack(&req->tx))
+                        free_count++;
 
         list_for_each_entry(req, &sba->reqs_alloc_list, node)
                 alloced_count++;
@@ -519,9 +494,6 @@ static void sba_write_stats_in_seqfile(struct sba_device *sba,
         list_for_each_entry(req, &sba->reqs_aborted_list, node)
                 aborted_count++;
 
-        list_for_each_entry(req, &sba->reqs_completed_list, node)
-                completed_count++;
-
         spin_unlock_irqrestore(&sba->reqs_lock, flags);
 
         seq_printf(file, "maximum requests   = %d\n", sba->max_req);
@@ -530,7 +502,6 @@ static void sba_write_stats_in_seqfile(struct sba_device *sba,
         seq_printf(file, "pending requests   = %d\n", pending_count);
         seq_printf(file, "active requests    = %d\n", active_count);
         seq_printf(file, "aborted requests   = %d\n", aborted_count);
-        seq_printf(file, "completed requests = %d\n", completed_count);
 }
 
 /* ====== DMAENGINE callbacks ===== */
@@ -1537,7 +1508,6 @@ 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_completed_list);
         INIT_LIST_HEAD(&sba->reqs_aborted_list);
         INIT_LIST_HEAD(&sba->reqs_free_list);
 
@@ -1565,6 +1535,7 @@ static int sba_prealloc_channel_resources(struct sba_device *sba)
                 }
                 memset(&req->msg, 0, sizeof(req->msg));
                 dma_async_tx_descriptor_init(&req->tx, &sba->dma_chan);
+                async_tx_ack(&req->tx);
                 req->tx.tx_submit = sba_tx_submit;
                 req->tx.phys = sba->resp_dma_base + i * sba->hw_resp_size;
                 list_add_tail(&req->node, &sba->reqs_free_list);