[PATCH master 1/2] net: fsl-fman: fix alignment of RX buffer

[PATCH master 1/2] net: fsl-fman: fix alignment of RX buffer

[Ahmad Fatoum]

The receive buffer needs to be cacheline aligned for cache maintenance
to avoid invalidating unrelated malloc memory. This was so far not the
case due to malloc's minimum alignment of 8-byte (with TLSF), so switch
to dma_alloc instead.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/net/fsl-fman.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/fsl-fman.c b/drivers/net/fsl-fman.c
index ff32fa8fc753..baafe027c079 100644
--- a/drivers/net/fsl-fman.c
+++ b/drivers/net/fsl-fman.c
@@ -620,9 +620,7 @@ static int fm_eth_rx_port_parameter_init(struct fm_eth *fm_eth)
 			* RX_BD_RING_SIZE);
 
 	/* alloc Rx buffer from main memory */
-	rx_buf_pool = malloc(MAX_RXBUF_LEN * RX_BD_RING_SIZE);
-	if (!rx_buf_pool)
-		return -ENOMEM;
+	rx_buf_pool = dma_alloc(MAX_RXBUF_LEN * RX_BD_RING_SIZE);
 
 	memset(rx_buf_pool, 0, MAX_RXBUF_LEN * RX_BD_RING_SIZE);
 
-- 
2.39.2

[PATCH master 2/2] net: fsl-fman: fix CONFIG_DMA_API_DEBUG warnings

[Ahmad Fatoum]

The first time a buffer is provided to a device, it needs to be mapped
with dma_map_single, before dma_sync_single_for_* may be called.

>From a cache coherence point of view, dma_map_single and
dma_sync_single_for_device have the same effect, but the former
is necessary, so DMA API debugging can catch issues.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/net/fsl-fman.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/net/fsl-fman.c b/drivers/net/fsl-fman.c
index baafe027c079..12cb240a37c0 100644
--- a/drivers/net/fsl-fman.c
+++ b/drivers/net/fsl-fman.c
@@ -583,7 +583,6 @@ static int fm_eth_rx_port_parameter_init(struct fm_eth *fm_eth)
 	void *rx_bd_ring_base;
 	void *rx_buf_pool;
 	u32 bd_ring_base_lo, bd_ring_base_hi;
-	u32 buf_lo, buf_hi;
 	struct fm_port_bd *rxbd;
 	struct fm_port_qd *rxqd;
 	struct fm_bmi_rx_port *bmi_rx_port = fm_eth->rx_port;
@@ -631,19 +630,21 @@ static int fm_eth_rx_port_parameter_init(struct fm_eth *fm_eth)
 
 	/* init Rx BDs ring */
 	for (i = 0; i < RX_BD_RING_SIZE; i++) {
+		dma_addr_t dma;
+
 		rxbd = &fm_eth->rx_bd_ring[i];
 
 		muram_writew(&rxbd->status, RxBD_EMPTY);
 		muram_writew(&rxbd->len, 0);
-		buf_hi = upper_32_bits(virt_to_phys(rx_buf_pool +
-					i * MAX_RXBUF_LEN));
-		buf_lo = lower_32_bits(virt_to_phys(rx_buf_pool +
-					i * MAX_RXBUF_LEN));
-		dma_sync_single_for_device(fm_eth->dev,
-					   (unsigned long)rx_buf_pool + i * MAX_RXBUF_LEN,
-					   MAX_RXBUF_LEN, DMA_FROM_DEVICE);
-		muram_writew(&rxbd->buf_ptr_hi, (u16)buf_hi);
-		out_be32(&rxbd->buf_ptr_lo, buf_lo);
+
+		dma = dma_map_single(fm_eth->dev,
+				     rx_buf_pool + i * MAX_RXBUF_LEN,
+				     MAX_RXBUF_LEN, DMA_FROM_DEVICE);
+		if (dma_mapping_error(fm_eth->dev, dma))
+			return -EFAULT;
+
+		muram_writew(&rxbd->buf_ptr_hi, (u16)upper_32_bits(dma));
+		out_be32(&rxbd->buf_ptr_lo, lower_32_bits(dma));
 	}
 
 	/* set the Rx queue descriptor */
-- 
2.39.2

Re: [PATCH master 1/2] net: fsl-fman: fix alignment of RX buffer

[Sascha Hauer]

On Mon, Jan 08, 2024 at 11:14:18AM +0100, Ahmad Fatoum wrote:
> The receive buffer needs to be cacheline aligned for cache maintenance
> to avoid invalidating unrelated malloc memory. This was so far not the
> case due to malloc's minimum alignment of 8-byte (with TLSF), so switch
> to dma_alloc instead.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  drivers/net/fsl-fman.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)

Applied, thanks

Sascha

> 
> diff --git a/drivers/net/fsl-fman.c b/drivers/net/fsl-fman.c
> index ff32fa8fc753..baafe027c079 100644
> --- a/drivers/net/fsl-fman.c
> +++ b/drivers/net/fsl-fman.c
> @@ -620,9 +620,7 @@ static int fm_eth_rx_port_parameter_init(struct fm_eth *fm_eth)
>  			* RX_BD_RING_SIZE);
>  
>  	/* alloc Rx buffer from main memory */
> -	rx_buf_pool = malloc(MAX_RXBUF_LEN * RX_BD_RING_SIZE);
> -	if (!rx_buf_pool)
> -		return -ENOMEM;
> +	rx_buf_pool = dma_alloc(MAX_RXBUF_LEN * RX_BD_RING_SIZE);
>  
>  	memset(rx_buf_pool, 0, MAX_RXBUF_LEN * RX_BD_RING_SIZE);
>  
> -- 
> 2.39.2
> 
> 
> 

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