[PATCH] firmware: stratix10-svc: kmalloc_array + kzalloc to flex

[Rosen Penev]

Use a flexible array member to combine allocations. Simplifies memory
management.

Add __counted_by for extra runtime analysis. Also move counting variable
assignment up as required by __counted_by.

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
 drivers/firmware/stratix10-svc.c | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
index e9e35d67ef96..e28adbc25eb4 100644
--- a/drivers/firmware/stratix10-svc.c
+++ b/drivers/firmware/stratix10-svc.c
@@ -243,7 +243,6 @@ struct stratix10_async_ctrl {
 /**
  * struct stratix10_svc_controller - service controller
  * @dev: device
- * @chans: array of service channels
  * @num_chans: number of channels in 'chans' array
  * @num_active_client: number of active service client
  * @node: list management
@@ -253,13 +252,13 @@ struct stratix10_async_ctrl {
  * @svc: manages the list of client svc drivers
  * @sdm_lock: only allows a single command single response to SDM
  * @actrl: async control structure
+ * @chans: array of service channels
  *
  * This struct is used to create communication channels for service clients, to
  * handle secure monitor or hypervisor call.
  */
 struct stratix10_svc_controller {
 	struct device *dev;
-	struct stratix10_svc_chan *chans;
 	int num_chans;
 	int num_active_client;
 	struct list_head node;
@@ -269,6 +268,7 @@ struct stratix10_svc_controller {
 	struct stratix10_svc *svc;
 	struct mutex sdm_lock;
 	struct stratix10_async_ctrl actrl;
+	struct stratix10_svc_chan chans[] __counted_by(num_chans);
 };
 
 /**
@@ -1901,7 +1901,6 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct stratix10_svc_controller *controller;
-	struct stratix10_svc_chan *chans;
 	struct gen_pool *genpool;
 	struct stratix10_svc_sh_memory *sh_memory;
 	struct stratix10_svc *svc = NULL;
@@ -1929,23 +1928,16 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 		return PTR_ERR(genpool);
 
 	/* allocate service controller and supporting channel */
-	controller = devm_kzalloc(dev, sizeof(*controller), GFP_KERNEL);
+	controller = devm_kzalloc(dev, struct_size(controller, chans, SVC_NUM_CHANNEL),
+				GFP_KERNEL);
 	if (!controller) {
 		ret = -ENOMEM;
 		goto err_destroy_pool;
 	}
 
-	chans = devm_kmalloc_array(dev, SVC_NUM_CHANNEL,
-				   sizeof(*chans), GFP_KERNEL | __GFP_ZERO);
-	if (!chans) {
-		ret = -ENOMEM;
-		goto err_destroy_pool;
-	}
-
-	controller->dev = dev;
 	controller->num_chans = SVC_NUM_CHANNEL;
+	controller->dev = dev;
 	controller->num_active_client = 0;
-	controller->chans = chans;
 	controller->genpool = genpool;
 	controller->invoke_fn = invoke_fn;
 	INIT_LIST_HEAD(&controller->node);
@@ -1962,16 +1954,16 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 	mutex_init(&controller->sdm_lock);
 
 	for (i = 0; i < SVC_NUM_CHANNEL; i++) {
-		chans[i].scl = NULL;
-		chans[i].ctrl = controller;
-		chans[i].name = (char *)chan_names[i];
-		spin_lock_init(&chans[i].lock);
-		ret = kfifo_alloc(&chans[i].svc_fifo, fifo_size, GFP_KERNEL);
+		controller->chans[i].scl = NULL;
+		controller->chans[i].ctrl = controller;
+		controller->chans[i].name = (char *)chan_names[i];
+		spin_lock_init(&controller->chans[i].lock);
+		ret = kfifo_alloc(&controller->chans[i].svc_fifo, fifo_size, GFP_KERNEL);
 		if (ret) {
 			dev_err(dev, "failed to allocate FIFO %d\n", i);
 			goto err_free_fifos;
 		}
-		spin_lock_init(&chans[i].svc_fifo_lock);
+		spin_lock_init(&controller->chans[i].svc_fifo_lock);
 	}
 
 	list_add_tail(&controller->node, &svc_ctrl);
@@ -2015,7 +2007,7 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 		list_del(&controller->node);
 	/* free only the FIFOs that were successfully allocated */
 	while (i--)
-		kfifo_free(&chans[i].svc_fifo);
+		kfifo_free(&controller->chans[i].svc_fifo);
 	stratix10_svc_async_exit(controller);
 err_destroy_pool:
 	gen_pool_destroy(genpool);
-- 
2.53.0