Consolidate the two-element allocation into a single allocation using a
flexible array member. This reduces memory fragmentation and simplifies
the error path by eliminating the need to check for allocation failure
between the two allocations.

Add __counted_by for runtime bounds checking.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v2: use macro for number of elements. reword commit message.
 drivers/accel/qaic/qaic.h     | 4 ++--
 drivers/accel/qaic/qaic_drv.c | 8 +++-----
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/accel/qaic/qaic.h b/drivers/accel/qaic/qaic.h
index fa7a8155658c..e237020f6aa9 100644
--- a/drivers/accel/qaic/qaic.h
+++ b/drivers/accel/qaic/qaic.h
@@ -152,8 +152,6 @@ struct qaic_device {
 	struct list_head	cntl_xfer_list;
 	/* Synchronizes MHI control device transactions and its xfer list */
 	struct mutex		cntl_mutex;
-	/* Array of DBC struct of this device */
-	struct dma_bridge_chan	*dbc;
 	/* Work queue for tasks related to MHI control device */
 	struct workqueue_struct	*cntl_wq;
 	/* Synchronizes all the users of device during cleanup */
@@ -206,6 +204,8 @@ struct qaic_device {
 	void			*ssr_mhi_buf;
 	/* DBC which is under SSR. Sentinel U32_MAX would mean that no SSR in progress */
 	u32			ssr_dbc;
+	/* Array of DBC struct of this device */
+	struct dma_bridge_chan	dbc[] __counted_by(num_dbc);
 };

 struct qaic_drm_device {
diff --git a/drivers/accel/qaic/qaic_drv.c b/drivers/accel/qaic/qaic_drv.c
index 63fb8c7b4abc..1dda8dfea5a4 100644
--- a/drivers/accel/qaic/qaic_drv.c
+++ b/drivers/accel/qaic/qaic_drv.c
@@ -43,6 +43,7 @@ MODULE_IMPORT_NS("DMA_BUF");
 #define QAIC_DESC			"Qualcomm Cloud AI Accelerators"
 #define CNTL_MAJOR			5
 #define CNTL_MINOR			0
+#define DBC_NUM				16

 struct qaic_device_config {
 	/* Indicates the AIC family the device belongs to */
@@ -405,15 +406,12 @@ static struct qaic_device *create_qdev(struct pci_dev *pdev,
 	struct drm_device *drm;
 	int i, ret;

-	qdev = devm_kzalloc(dev, sizeof(*qdev), GFP_KERNEL);
+	qdev = devm_kzalloc(dev, struct_size(qdev, dbc, DBC_NUM), GFP_KERNEL);
 	if (!qdev)
 		return NULL;

+	qdev->num_dbc = DBC_NUM;
 	qdev->dev_state = QAIC_OFFLINE;
-	qdev->num_dbc = 16;
-	qdev->dbc = devm_kcalloc(dev, qdev->num_dbc, sizeof(*qdev->dbc), GFP_KERNEL);
-	if (!qdev->dbc)
-		return NULL;

 	qddev = devm_drm_dev_alloc(&pdev->dev, &qaic_accel_driver, struct qaic_drm_device, drm);
 	if (IS_ERR(qddev))
--
2.53.0