Re: [PATCH V2] octeon_ep: Remove unnecessary cast

[Joe Perches <joe@perches.com>]

On Tue, 2022-05-24 at 11:28 +0800, Haowen Bai wrote:
> ./drivers/net/ethernet/marvell/octeon_ep/octep_rx.c:161:18-40: WARNING:
> casting value returned by memory allocation function to (struct
> octep_rx_buffer *) is useless.
[]
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
[]
> @@ -158,8 +158,7 @@ static int octep_setup_oq(struct octep_device *oct, int q_no)
>  		goto desc_dma_alloc_err;
>  	}
>  
> -	oq->buff_info = (struct octep_rx_buffer *)
> -			vzalloc(oq->max_count * OCTEP_OQ_RECVBUF_SIZE);
> +	oq->buff_info = vcalloc(oq->max_count, OCTEP_OQ_RECVBUF_SIZE);

trivia:

Perhaps better to remove the used once #define OCTEP_OQ_RECVBUF_SIZE
and use the more obvious

	oq->buff_info = vcalloc(oq->max_count, sizeof(struct octep_rx_buffer));

though I believe the vcalloc may be better as kvcalloc as max_count isn't
particularly high and struct octep_rx_buffer is small.

Maybe:
---
 drivers/net/ethernet/marvell/octeon_ep/octep_rx.c | 8 ++++----
 drivers/net/ethernet/marvell/octeon_ep/octep_rx.h | 2 --
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
index d9ae0937d17a8..d6a0da61db449 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
@@ -158,8 +158,8 @@ static int octep_setup_oq(struct octep_device *oct, int q_no)
 		goto desc_dma_alloc_err;
 	}
 
-	oq->buff_info = (struct octep_rx_buffer *)
-			vzalloc(oq->max_count * OCTEP_OQ_RECVBUF_SIZE);
+	oq->buff_info = kvcalloc(oq->max_count, sizeof(struct octep_rx_buffer),
+				 GFP_KERNEL);
 	if (unlikely(!oq->buff_info)) {
 		dev_err(&oct->pdev->dev,
 			"Failed to allocate buffer info for OQ-%d\n", q_no);
@@ -176,7 +176,7 @@ static int octep_setup_oq(struct octep_device *oct, int q_no)
 	return 0;
 
 oq_fill_buff_err:
-	vfree(oq->buff_info);
+	kvfree(oq->buff_info);
 	oq->buff_info = NULL;
 buf_list_err:
 	dma_free_coherent(oq->dev, desc_ring_size,
@@ -230,7 +230,7 @@ static int octep_free_oq(struct octep_oq *oq)
 
 	octep_oq_free_ring_buffers(oq);
 
-	vfree(oq->buff_info);
+	kvfree(oq->buff_info);
 
 	if (oq->desc_ring)
 		dma_free_coherent(oq->dev,
diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h
index 782a24f27f3e0..34a32d95cd4b3 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h
@@ -67,8 +67,6 @@ struct octep_rx_buffer {
 	u64 len;
 };
 
-#define OCTEP_OQ_RECVBUF_SIZE    (sizeof(struct octep_rx_buffer))
-
 /* Output Queue statistics. Each output queue has four stats fields. */
 struct octep_oq_stats {
 	/* Number of packets received from the Device. */