Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751570AbdGZFiC (ORCPT ); Wed, 26 Jul 2017 01:38:02 -0400 Received: from mail-wr0-f182.google.com ([209.85.128.182]:35701 "EHLO mail-wr0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751533AbdGZFh7 (ORCPT ); Wed, 26 Jul 2017 01:37:59 -0400 From: Anup Patel To: Rob Herring , Mark Rutland , Vinod Koul , Dan Williams Cc: Florian Fainelli , Scott Branden , Ray Jui , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, dmaengine@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, Anup Patel Subject: [PATCH 4/6] dma: bcm-sba-raid: Break sba_process_deferred_requests() into two parts Date: Wed, 26 Jul 2017 11:06:42 +0530 Message-Id: <1501047404-14456-5-git-send-email-anup.patel@broadcom.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1501047404-14456-1-git-send-email-anup.patel@broadcom.com> References: <1501047404-14456-1-git-send-email-anup.patel@broadcom.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7705 Lines: 241 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 Reviewed-by: Scott Branden --- 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 ( * 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