6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Chan [ Upstream commit 107b25db61122d8f990987895c2912927b8b6e3f ] The bd_cnt field in the TX BD specifies the total number of BDs for the TX packet. The bd_cnt field has 5 bits and the maximum number supported is 32 with the value 0. CONFIG_MAX_SKB_FRAGS can be modified and the total number of SKB fragments can approach or exceed the maximum supported by the chip. Add a macro to properly mask the bd_cnt field so that the value 32 will be properly masked and set to 0 in the bd_cnd field. Without this patch, the out-of-range bd_cnt value will corrupt the TX BD and may cause TX timeout. The next patch will check for values exceeding 32. Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAGS") Reviewed-by: Kalesh AP Reviewed-by: Somnath Kotur Reviewed-by: Andy Gospodarek Signed-off-by: Michael Chan Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250321211639.3812992-2-michael.chan@broadcom.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++-- drivers/net/ethernet/broadcom/bnxt/bnxt.h | 2 ++ drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 3 +-- 3 files changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 239dc465348ba..e066f44e900b6 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -494,7 +494,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) TX_BD_FLAGS_LHINT_512_AND_SMALLER | TX_BD_FLAGS_COAL_NOW | TX_BD_FLAGS_PACKET_END | - (2 << TX_BD_FLAGS_BD_CNT_SHIFT)); + TX_BD_CNT(2)); if (skb->ip_summed == CHECKSUM_PARTIAL) tx_push1->tx_bd_hsize_lflags = @@ -560,7 +560,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) dma_unmap_addr_set(tx_buf, mapping, mapping); flags = (len << TX_BD_LEN_SHIFT) | TX_BD_TYPE_LONG_TX_BD | - ((last_frag + 2) << TX_BD_FLAGS_BD_CNT_SHIFT); + TX_BD_CNT(last_frag + 2); txbd->tx_bd_haddr = cpu_to_le64(mapping); txbd->tx_bd_opaque = SET_TX_OPAQUE(bp, prod, 2 + last_frag); diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index 67ec15eae5d57..4c1598d475059 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -74,6 +74,8 @@ struct tx_bd { #define TX_OPAQUE_PROD(bp, opq) ((TX_OPAQUE_IDX(opq) + TX_OPAQUE_BDS(opq)) &\ (bp)->tx_ring_mask) +#define TX_BD_CNT(n) (((n) << TX_BD_FLAGS_BD_CNT_SHIFT) & TX_BD_FLAGS_BD_CNT) + struct tx_bd_ext { __le32 tx_bd_hsize_lflags; #define TX_BD_FLAGS_TCP_UDP_CHKSUM (1 << 0) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c index 5e62172fb5f29..f3e322e7d61cc 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c @@ -48,8 +48,7 @@ struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp, tx_buf->page = virt_to_head_page(xdp->data); txbd = &txr->tx_desc_ring[TX_RING(bp, prod)][TX_IDX(prod)]; - flags = (len << TX_BD_LEN_SHIFT) | - ((num_frags + 1) << TX_BD_FLAGS_BD_CNT_SHIFT) | + flags = (len << TX_BD_LEN_SHIFT) | TX_BD_CNT(num_frags + 1) | bnxt_lhint_arr[len >> 9]; txbd->tx_bd_len_flags_type = cpu_to_le32(flags); txbd->tx_bd_opaque = SET_TX_OPAQUE(bp, prod, 1 + num_frags); -- 2.53.0