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| author | Alex Elder <elder@riscstar.com> | 2026-08-12 11:38:31 -0500 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-08-17 11:21:49 -0700 |
| commit | c11c497af866ccd11c109de0833b2cd89cddd075 (patch) | |
| tree | 7780807fe69611b016f9ad7682372a2bb82789db | |
| parent | 0c1f9020d2ada55aed8a2e055903ad9cd5d49dab (diff) | |
| download | linux-next-c11c497af866ccd11c109de0833b2cd89cddd075.tar.gz linux-next-c11c497af866ccd11c109de0833b2cd89cddd075.zip | |
net: stmmac: convert DMA address to lower 32 before assignment
In jumbo_frm() (implemented in both "chain_mode.c" and "ring_mode.c"),
there are places where a DMA descriptor is converted to little-endian
byte order in assignment. The DMA descriptor could be a 64-bit value,
which makes the 32-bit byte swapping operation seem a little sketchy.
Explicitly extract the low-order 32 bits of the dma_addr_t value being
converted into a u32 so it's crystal clear that we're doing the right
thing.
Suggested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Alex Elder <elder@riscstar.com>
Link: https://patch.msgid.link/20260812163832.271742-3-elder@riscstar.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/chain_mode.c | 6 | ||||
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/ring_mode.c | 12 |
2 files changed, 9 insertions, 9 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c index ec25193d287b..66025e2509e9 100644 --- a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c +++ b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c @@ -37,7 +37,7 @@ static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb, des2 = dma_map_single(priv->device, skb->data, buf_len, DMA_TO_DEVICE); - desc->des2 = cpu_to_le32(des2); + desc->des2 = cpu_to_le32(lower_32_bits(des2)); if (dma_mapping_error(priv->device, des2)) return -1; tx_q->tx_skbuff_dma[entry].buf = des2; @@ -55,7 +55,7 @@ static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb, des2 = dma_map_single(priv->device, (skb->data + bmax * i), bmax, DMA_TO_DEVICE); - desc->des2 = cpu_to_le32(des2); + desc->des2 = cpu_to_le32(lower_32_bits(des2)); if (dma_mapping_error(priv->device, des2)) return -1; tx_q->tx_skbuff_dma[entry].buf = des2; @@ -68,7 +68,7 @@ static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb, des2 = dma_map_single(priv->device, (skb->data + bmax * i), len, DMA_TO_DEVICE); - desc->des2 = cpu_to_le32(des2); + desc->des2 = cpu_to_le32(lower_32_bits(des2)); if (dma_mapping_error(priv->device, des2)) return -1; tx_q->tx_skbuff_dma[entry].buf = des2; diff --git a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c index 664d8cfb58cd..f7949419eb9f 100644 --- a/drivers/net/ethernet/stmicro/stmmac/ring_mode.c +++ b/drivers/net/ethernet/stmicro/stmmac/ring_mode.c @@ -40,7 +40,7 @@ static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb, des2 = dma_map_single(priv->device, skb->data, bmax, DMA_TO_DEVICE); - desc->des2 = cpu_to_le32(des2); + desc->des2 = cpu_to_le32(lower_32_bits(des2)); if (dma_mapping_error(priv->device, des2)) return -1; @@ -48,7 +48,7 @@ static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb, tx_q->tx_skbuff_dma[entry].len = bmax; tx_q->tx_skbuff_dma[entry].is_jumbo = true; - desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); + desc->des3 = cpu_to_le32(lower_32_bits(des2) + BUF_SIZE_4KiB); stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum, STMMAC_RING_MODE, 0, false, skb->len); tx_q->tx_skbuff[entry] = NULL; @@ -61,27 +61,27 @@ static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb, des2 = dma_map_single(priv->device, skb->data + bmax, len, DMA_TO_DEVICE); - desc->des2 = cpu_to_le32(des2); + desc->des2 = cpu_to_le32(lower_32_bits(des2)); if (dma_mapping_error(priv->device, des2)) return -1; tx_q->tx_skbuff_dma[entry].buf = des2; tx_q->tx_skbuff_dma[entry].len = len; tx_q->tx_skbuff_dma[entry].is_jumbo = true; - desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); + desc->des3 = cpu_to_le32(lower_32_bits(des2) + BUF_SIZE_4KiB); stmmac_prepare_tx_desc(priv, desc, 0, len, csum, STMMAC_RING_MODE, 1, !skb_is_nonlinear(skb), skb->len); } else { des2 = dma_map_single(priv->device, skb->data, nopaged_len, DMA_TO_DEVICE); - desc->des2 = cpu_to_le32(des2); + desc->des2 = cpu_to_le32(lower_32_bits(des2)); if (dma_mapping_error(priv->device, des2)) return -1; tx_q->tx_skbuff_dma[entry].buf = des2; tx_q->tx_skbuff_dma[entry].len = nopaged_len; tx_q->tx_skbuff_dma[entry].is_jumbo = true; - desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); + desc->des3 = cpu_to_le32(lower_32_bits(des2) + BUF_SIZE_4KiB); stmmac_prepare_tx_desc(priv, desc, 1, nopaged_len, csum, STMMAC_RING_MODE, 0, !skb_is_nonlinear(skb), skb->len); |