dmaengine: bcm-sba-raid: Allow arbitrary number free sba_request

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>

diff --git a/drivers/dma/bcm-sba-raid.c b/drivers/dma/bcm-sba-raid.c
index fdc9891..9ab2d95 100644 (file)
--- a/drivers/dma/bcm-sba-raid.c
+++ b/drivers/dma/bcm-sba-raid.c
@@ -113,9 +113,10 @@ struct sba_request {
        struct list_head next;
        atomic_t next_pending_count;
        /* BRCM message data */
-       struct brcm_sba_command *cmds;
        struct brcm_message msg;
        struct dma_async_tx_descriptor tx;
+       /* SBA commands */
+       struct brcm_sba_command cmds[0];
 };
 
 enum sba_version {
@@ -153,7 +154,6 @@ struct sba_device {
        void *cmds_base;
        dma_addr_t cmds_dma_base;
        spinlock_t reqs_lock;
-       struct sba_request *reqs;
        bool reqs_fence;
        struct list_head reqs_alloc_list;
        struct list_head reqs_pending_list;
@@ -1484,26 +1484,20 @@ static int sba_prealloc_channel_resources(struct sba_device *sba)
        INIT_LIST_HEAD(&sba->reqs_aborted_list);
        INIT_LIST_HEAD(&sba->reqs_free_list);
 
-       sba->reqs = devm_kcalloc(sba->dev, sba->max_req,
-                                sizeof(*req), GFP_KERNEL);
-       if (!sba->reqs) {
-               ret = -ENOMEM;
-               goto fail_free_cmds_pool;
-       }
-
        for (i = 0; i < sba->max_req; i++) {
-               req = &sba->reqs[i];
+               req = devm_kzalloc(sba->dev,
+                               sizeof(*req) +
+                               sba->max_cmd_per_req * sizeof(req->cmds[0]),
+                               GFP_KERNEL);
+               if (!req) {
+                       ret = -ENOMEM;
+                       goto fail_free_cmds_pool;
+               }
                INIT_LIST_HEAD(&req->node);
                req->sba = sba;
                req->flags = SBA_REQUEST_STATE_FREE;
                INIT_LIST_HEAD(&req->next);
                atomic_set(&req->next_pending_count, 0);
-               req->cmds = devm_kcalloc(sba->dev, sba->max_cmd_per_req,
-                                        sizeof(*req->cmds), GFP_KERNEL);
-               if (!req->cmds) {
-                       ret = -ENOMEM;
-                       goto fail_free_cmds_pool;
-               }
                for (j = 0; j < sba->max_cmd_per_req; j++) {
                        req->cmds[j].cmd = 0;
                        req->cmds[j].cmd_dma = sba->cmds_base +