From: Anup Patel <anup.patel@broadcom.com>
To: Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Vinod Koul <vinod.koul@intel.com>,
Dan Williams <dan.j.williams@intel.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
Scott Branden <sbranden@broadcom.com>,
Ray Jui <rjui@broadcom.com>,
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 <anup.patel@broadcom.com>
Subject: [PATCH v2 02/16] dmaengine: bcm-sba-raid: Reduce locking context in sba_alloc_request()
Date: Tue, 1 Aug 2017 16:07:46 +0530 [thread overview]
Message-ID: <1501583880-32072-3-git-send-email-anup.patel@broadcom.com> (raw)
In-Reply-To: <1501583880-32072-1-git-send-email-anup.patel@broadcom.com>
We don't require to hold "sba->reqs_lock" for long-time
in sba_alloc_request() because lock protection is not
required when initializing members of "struct sba_request".
Signed-off-by: Anup Patel <anup.patel@broadcom.com>
---
drivers/dma/bcm-sba-raid.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/dma/bcm-sba-raid.c b/drivers/dma/bcm-sba-raid.c
index 76999b7..f81d5ac 100644
--- a/drivers/dma/bcm-sba-raid.c
+++ b/drivers/dma/bcm-sba-raid.c
@@ -207,24 +207,24 @@ static struct sba_request *sba_alloc_request(struct sba_device *sba)
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);
- req->state = SBA_REQUEST_STATE_ALLOCED;
- req->fence = false;
- req->first = req;
- INIT_LIST_HEAD(&req->next);
- req->next_count = 1;
- atomic_set(&req->next_pending_count, 1);
-
sba->reqs_free_count--;
-
- dma_async_tx_descriptor_init(&req->tx, &sba->dma_chan);
}
-
spin_unlock_irqrestore(&sba->reqs_lock, flags);
+ if (!req)
+ return NULL;
+
+ req->state = SBA_REQUEST_STATE_ALLOCED;
+ req->fence = false;
+ req->first = req;
+ INIT_LIST_HEAD(&req->next);
+ req->next_count = 1;
+ atomic_set(&req->next_pending_count, 1);
+
+ dma_async_tx_descriptor_init(&req->tx, &sba->dma_chan);
return req;
}
--
2.7.4
next prev parent reply other threads:[~2017-08-01 10:38 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-01 10:37 [PATCH v2 00/16] Broadcom SBA-RAID driver improvements Anup Patel
2017-08-01 10:37 ` [PATCH v2 01/16] dmaengine: bcm-sba-raid: Minor improvments in comments Anup Patel
2017-08-17 3:44 ` Vinod Koul
2017-08-18 4:54 ` Anup Patel
2017-08-01 10:37 ` Anup Patel [this message]
2017-08-01 10:37 ` [PATCH v2 03/16] dmaengine: bcm-sba-raid: Common flags for sba_request state and fence Anup Patel
2017-08-17 3:45 ` Vinod Koul
2017-08-18 4:56 ` Anup Patel
2017-08-18 5:25 ` Vinod Koul
2017-08-18 6:05 ` Anup Patel
2017-08-01 10:37 ` [PATCH v2 04/16] dmaengine: bcm-sba-raid: Remove redundant next_count from sba_request Anup Patel
2017-08-01 10:37 ` [PATCH v2 05/16] dmaengine: bcm-sba-raid: Remove redundant resp_dma " Anup Patel
2017-08-01 10:37 ` [PATCH v2 06/16] dmaengine: bcm-sba-raid: Remove reqs_free_count from sba_device Anup Patel
2017-08-01 10:37 ` [PATCH v2 07/16] dmaengine: bcm-sba-raid: Allow arbitrary number free sba_request Anup Patel
2017-08-01 10:37 ` [PATCH v2 08/16] dmaengine: bcm-sba-raid: Increase number of " Anup Patel
2017-08-01 10:37 ` [PATCH v2 09/16] dmaengine: bcm-sba-raid: Improve sba_issue_pending() run duration Anup Patel
2017-08-17 6:36 ` Vinod Koul
2017-08-18 6:12 ` Anup Patel
2017-08-01 10:37 ` [PATCH v2 10/16] dmaengine: bcm-sba-raid: Alloc resources before registering DMA device Anup Patel
2017-08-17 6:38 ` Vinod Koul
2017-08-18 5:01 ` Anup Patel
2017-08-01 10:37 ` [PATCH v2 11/16] dmaengine: bcm-sba-raid: Peek mbox when we have no free requests Anup Patel
2017-08-17 6:40 ` Vinod Koul
2017-08-18 11:36 ` Anup Patel
2017-08-01 10:37 ` [PATCH v2 12/16] dmaengine: bcm-sba-raid: Pre-ack async tx descriptor Anup Patel
2017-08-01 10:37 ` [PATCH v2 13/16] dmaengine: bcm-sba-raid: Re-factor sba_process_deferred_requests() Anup Patel
2017-08-01 10:37 ` [PATCH v2 14/16] dmaengine: bcm-sba-raid: Remove redundant SBA_REQUEST_STATE_RECEIVED Anup Patel
2017-08-01 10:37 ` [PATCH v2 15/16] dmaengine: bcm-sba-raid: Add debugfs support Anup Patel
2017-08-17 8:01 ` Vinod Koul
2017-08-18 5:03 ` Anup Patel
2017-08-18 5:26 ` Vinod Koul
2017-08-18 5:25 ` Anup Patel
2017-09-07 19:37 ` Greg KH
2017-09-08 4:09 ` Vinod Koul
2017-08-01 10:38 ` [PATCH v2 16/16] dmaengine: bcm-sba-raid: Explicitly ACK mailbox message after sending Anup Patel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1501583880-32072-3-git-send-email-anup.patel@broadcom.com \
--to=anup.patel@broadcom.com \
--cc=bcm-kernel-feedback-list@broadcom.com \
--cc=dan.j.williams@intel.com \
--cc=devicetree@vger.kernel.org \
--cc=dmaengine@vger.kernel.org \
--cc=f.fainelli@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=rjui@broadcom.com \
--cc=robh+dt@kernel.org \
--cc=sbranden@broadcom.com \
--cc=vinod.koul@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).