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path: root/drivers/dma/bcm-sba-raid.c
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2020-02-13dmaengine: bcm-sba-raid: Replace zero-length array with flexible-array memberGustavo A. R. Silva1-1/+1
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Link: https://lore.kernel.org/r/20200213003703.GA4177@embeddedor.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-06-14dmaengine: bcm-sba-raid: no need to check return value of debugfs_create ↵Greg Kroah-Hartman1-10/+3
functions When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Also, because there is no need to save the file dentry, remove the variable that was saving it as it was never even being used once set. Cc: Vinod Koul <vkoul@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: dmaengine@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-04-29dmaengine: bcm-sba-raid: Use dev_get_drvdata()Kefeng Wang1-2/+1
Using dev_get_drvdata directly. Cc: Vinod Koul <vinod.koul@intel.com> Cc: dmaengine@vger.kernel.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Vinod Koul <vkoul@kernel.org>
2018-06-06treewide: Use struct_size() for devm_kmalloc() and friendsKees Cook1-3/+2
Replaces open-coded struct size calculations with struct_size() for devm_*, f2fs_*, and sock_* allocations. Automatically generated (and manually adjusted) from the following Coccinelle script: // Direct reference to struct field. @@ identifier alloc =~ "devm_kmalloc|devm_kzalloc|sock_kmalloc|f2fs_kmalloc|f2fs_kzalloc"; expression HANDLE; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(HANDLE, sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP) + alloc(HANDLE, struct_size(VAR, ELEMENT, COUNT), GFP) // mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL); @@ identifier alloc =~ "devm_kmalloc|devm_kzalloc|sock_kmalloc|f2fs_kmalloc|f2fs_kzalloc"; expression HANDLE; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(HANDLE, sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP) + alloc(HANDLE, struct_size(VAR, ELEMENT, COUNT), GFP) // Same pattern, but can't trivially locate the trailing element name, // or variable name. @@ identifier alloc =~ "devm_kmalloc|devm_kzalloc|sock_kmalloc|f2fs_kmalloc|f2fs_kzalloc"; expression HANDLE; expression GFP; expression SOMETHING, COUNT, ELEMENT; @@ - alloc(HANDLE, sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP) + alloc(HANDLE, CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP) Signed-off-by: Kees Cook <keescook@chromium.org>
2017-10-23dmaengine: bcm-sba-raid: Use common GPL comment headerAnup Patel1-3/+8
This patch makes the comment header of Broadcom SBA RAID driver similar to the GPL comment header used across Broadcom driver sources. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-10-23dmaengine: bcm-sba-raid: Use only single mailbox channelAnup Patel1-77/+27
Each mailbox channel used by Broadcom SBA RAID driver is a separate HW ring. Currently, Broadcom SBA RAID driver creates one DMA channel using one or more mailbox channels. When we are using more than one mailbox channels for a DMA channel, the sba_request are distributed evenly among multiple mailbox channels which results in sba_request being completed out-of-order. The above described out-of-order completion of sba_request breaks the dma_async_is_complete() API because it assumes DMA cookies are completed in orderly fashion. To ensure correct behaviour of dma_async_is_complete() API, this patch updates Broadcom SBA RAID driver to use only single mailbox channel. If additional mailbox channels are specified in DT then those will be ignored. 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>
2017-10-23dmaengine: bcm-sba-raid: serialize dma_cookie_complete() using reqs_lockAnup Patel1-0/+2
As-per documentation in driver/dma/dmaengine.h, the dma_cookie_complete() API should be called with lock held. This patch ensures that Broadcom SBA RAID driver calls the dma_cookie_complete() API with reqs_lock held. 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>
2017-08-28dmaengine: bcm-sba-raid: Remove redundant SBA_REQUEST_STATE_COMPLETEDAnup Patel1-46/+17
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>
2017-08-28dmaengine: bcm-sba-raid: Explicitly ACK mailbox message after sendingAnup Patel1-3/+7
We should explicitly ACK mailbox message because after sending message we can know the send status via error attribute of brcm_message. This will also help SBA-RAID to use "txdone_ack" method whenever mailbox controller supports it. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Add debugfs supportAnup Patel1-0/+78
This patch adds debugfs support to report stats via debugfs which in-turn will help debug hang or error situations. 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>
2017-08-28dmaengine: bcm-sba-raid: Remove redundant SBA_REQUEST_STATE_RECEIVEDAnup Patel1-24/+2
The SBA_REQUEST_STATE_RECEIVED state is now redundant because received sba_request are immediately freed or moved to completed list in sba_process_received_request(). This patch removes redundant SBA_REQUEST_STATE_RECEIVED state. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Re-factor sba_process_deferred_requests()Anup Patel1-62/+47
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>
2017-08-28dmaengine: bcm-sba-raid: Pre-ack async tx descriptorAnup Patel1-0/+1
We should pre-ack async tx descriptor at time of allocating sba_request (just like other RAID drivers). 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>
2017-08-28dmaengine: bcm-sba-raid: Peek mbox when we have no free requestsAnup Patel1-5/+20
When setting up RAID array on several NVMe disks we observed that sba_alloc_request() start failing (due to no free requests left) and RAID array setup becomes very slow. To improve performance, we do mbox channel peek when we have no free requests. This improves performance of RAID array setup because mbox requests that were completed but not processed by mbox completion worker will be processed immediately by mbox channel peek. 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>
2017-08-28dmaengine: bcm-sba-raid: Alloc resources before registering DMA deviceAnup Patel1-15/+15
We should allocate DMA channel resources before registering the DMA device in sba_probe() because we can get DMA request soon after registering the DMA device. If DMA channel resources are not allocated before first DMA request then SBA-RAID driver will crash. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Improve sba_issue_pending() run durationAnup Patel1-109/+125
The pending sba_request list can become very long in real-life usage (e.g. setting up RAID array) which can cause sba_issue_pending() to run for long duration. This patch adds common sba_process_deferred_requests() to process few completed and pending requests so that it finishes in short duration. We use this common sba_process_deferred_requests() in both sba_issue_pending() and sba_receive_message(). Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Increase number of free sba_requestAnup Patel1-12/+13
Currently, we have only 1024 free sba_request created by sba_prealloc_channel_resources(). This is too low and the prep_xxx() callbacks start failing more often at time of RAID array setup over NVMe disks. This patch sets number of free sba_request created by sba_prealloc_channel_resources() to be: <number_of_mailbox_channels> x 8192 Due to above, we will have sufficient number of free sba_request and prep_xxx() callbacks failing is very unlikely. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Allow arbitrary number free sba_requestAnup Patel1-16/+10
Currently, we cannot have any arbitrary number of free sba_request because sba_prealloc_channel_resources() allocates an array of sba_request using devm_kcalloc() and kcalloc() cannot provide memory beyond certain size. This patch removes "reqs" (sba_request array) from sba_device and makes "cmds" as variable array (instead of pointer) in sba_request. This helps sba_prealloc_channel_resources() to allocate sba_request and associated SBA command in one allocation which in-turn allows arbitrary number of free sba_request. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Remove reqs_free_count from sba_deviceAnup Patel1-7/+1
The reqs_free_count member of sba_device is not used anywhere hence no point in tracking number of free sba_request. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Remove redundant resp_dma from sba_requestAnup Patel1-17/+17
Both resp and resp_dma are redundant in sba_request because resp is unused and resp_dma carries same information present in tx.phys of sba_request. This patch removes both resp and resp_dma from sba_request. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Remove redundant next_count from sba_requestAnup Patel1-5/+1
The next_count in sba_request is redundant because same information is captured by next_pending_count. This patch removes next_count from sba_request. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Common flags for sba_request state and fenceAnup Patel1-28/+38
This patch merges sba_request state and fence into common sba_request flags. The sba_request flags not only saves memory but it can also be extended in-future without adding new members. We also make each sba_request state as separate bit in sba_request flags to help debugging situations where a sba_request is accidently in two states. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Reduce locking context in sba_alloc_request()Anup Patel1-11/+11
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> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-08-28dmaengine: bcm-sba-raid: Minor improvments in commentsAnup Patel1-3/+6
This patch does following improvments to comments: 1. Make section comments consistent across the driver by avoiding " SBA " in some of the comments 2. Add/update few more section comments Signed-off-by: Anup Patel <anup.patel@broadcom.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-07-19dmaengine: bcm-scm-raid: statify functionsVinod Koul1-3/+3
This driver builds with warnings which can be fixed by making these functions static. CC [M] drivers/dma/bcm-sba-raid.o drivers/dma/bcm-sba-raid.c:786:1: warning: no previous prototype for ‘sba_prep_dma_xor_req’ [-Wmissing-prototypes] sba_prep_dma_xor_req(struct sba_device *sba, ^ drivers/dma/bcm-sba-raid.c:995:1: warning: no previous prototype for ‘sba_prep_dma_pq_req’ [-Wmissing-prototypes] sba_prep_dma_pq_req(struct sba_device *sba, dma_addr_t off, ^ drivers/dma/bcm-sba-raid.c:1247:1: warning: no previous prototype for ‘sba_prep_dma_pq_single_req’ [-Wmissing-prototypes] sba_prep_dma_pq_single_req(struct sba_device *sba, dma_addr_t off, ^ Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-05-19dmaengine: bcm-scm-raid: remove redundant null check on reqColin Ian King1-1/+1
Req is never null on at the point of the null check, so remove this redundant check and just return &req->tx. Detected by CoverityScan, CID#1436147 ("Logically dead code") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-05-16dmaengine: Add Broadcom SBA RAID driverAnup Patel1-0/+1785
The Broadcom stream buffer accelerator (SBA) provides offloading capabilities for RAID operations. This SBA offload engine is accessible via Broadcom SoC specific ring manager. This patch adds Broadcom SBA RAID driver which provides one DMA device with RAID capabilities using one or more Broadcom SoC specific ring manager channels. The SBA RAID driver in its current shape implements memcpy, xor, and pq operations. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>