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

Ahmad Fatoum a.fatoum at pengutronix.de
Mon Jan 8 02:14:19 PST 2024


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 at 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




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