From 262d98b1193fec68c66f3d57772b72240fc4b9da Mon Sep 17 00:00:00 2001 From: Ricardo Martinez Date: Fri, 13 May 2022 10:33:59 -0700 Subject: [PATCH 1/2] net: wwan: t7xx: Avoid calls to skb_data_area_size() skb_data_area_size() helper was used to calculate the size of the DMA mapped buffer passed to the HW. Instead of doing this, use the size passed to allocate the skbs. Signed-off-by: Ricardo Martinez Reviewed-by: Andy Shevchenko Reviewed-by: Sergey Ryazanov Signed-off-by: Jakub Kicinski --- drivers/net/wwan/t7xx/t7xx_hif_cldma.c | 7 +++---- drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c | 6 ++---- 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c index 46066dcd2607..0c52801ed0de 100644 --- a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c +++ b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c @@ -97,8 +97,7 @@ static int t7xx_cldma_alloc_and_map_skb(struct cldma_ctrl *md_ctrl, struct cldma if (!req->skb) return -ENOMEM; - req->mapped_buff = dma_map_single(md_ctrl->dev, req->skb->data, - skb_data_area_size(req->skb), DMA_FROM_DEVICE); + req->mapped_buff = dma_map_single(md_ctrl->dev, req->skb->data, size, DMA_FROM_DEVICE); if (dma_mapping_error(md_ctrl->dev, req->mapped_buff)) { dev_kfree_skb_any(req->skb); req->skb = NULL; @@ -154,7 +153,7 @@ static int t7xx_cldma_gpd_rx_from_q(struct cldma_queue *queue, int budget, bool if (req->mapped_buff) { dma_unmap_single(md_ctrl->dev, req->mapped_buff, - skb_data_area_size(skb), DMA_FROM_DEVICE); + queue->tr_ring->pkt_size, DMA_FROM_DEVICE); req->mapped_buff = 0; } @@ -376,7 +375,7 @@ static void t7xx_cldma_ring_free(struct cldma_ctrl *md_ctrl, list_for_each_entry_safe(req_cur, req_next, &ring->gpd_ring, entry) { if (req_cur->mapped_buff && req_cur->skb) { dma_unmap_single(md_ctrl->dev, req_cur->mapped_buff, - skb_data_area_size(req_cur->skb), tx_rx); + ring->pkt_size, tx_rx); req_cur->mapped_buff = 0; } diff --git a/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c b/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c index 35a8a0d7c1ee..91a0eb19e0d8 100644 --- a/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c +++ b/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c @@ -151,14 +151,12 @@ static bool t7xx_alloc_and_map_skb_info(const struct dpmaif_ctrl *dpmaif_ctrl, { dma_addr_t data_bus_addr; struct sk_buff *skb; - size_t data_len; skb = __dev_alloc_skb(size, GFP_KERNEL); if (!skb) return false; - data_len = skb_data_area_size(skb); - data_bus_addr = dma_map_single(dpmaif_ctrl->dev, skb->data, data_len, DMA_FROM_DEVICE); + data_bus_addr = dma_map_single(dpmaif_ctrl->dev, skb->data, size, DMA_FROM_DEVICE); if (dma_mapping_error(dpmaif_ctrl->dev, data_bus_addr)) { dev_err_ratelimited(dpmaif_ctrl->dev, "DMA mapping error\n"); dev_kfree_skb_any(skb); @@ -167,7 +165,7 @@ static bool t7xx_alloc_and_map_skb_info(const struct dpmaif_ctrl *dpmaif_ctrl, cur_skb->skb = skb; cur_skb->data_bus_addr = data_bus_addr; - cur_skb->data_len = data_len; + cur_skb->data_len = size; return true; } From 89af2ce2d95c80f6da9388d9da2e35c84c2573b1 Mon Sep 17 00:00:00 2001 From: Ricardo Martinez Date: Fri, 13 May 2022 10:34:00 -0700 Subject: [PATCH 2/2] net: skb: Remove skb_data_area_size() skb_data_area_size() is not needed. As Jakub pointed out [1]: For Rx, drivers can use the size passed during skb allocation or use skb_tailroom(). For Tx, drivers should use skb_headlen(). [1] https://lore.kernel.org/netdev/CAHNKnsTmH-rGgWi3jtyC=ktM1DW2W1VJkYoTMJV2Z_Bt498bsg@mail.gmail.com/ Signed-off-by: Ricardo Martinez Reviewed-by: Andy Shevchenko Reviewed-by: Sergey Ryazanov Signed-off-by: Jakub Kicinski --- include/linux/skbuff.h | 5 ----- 1 file changed, 5 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 5a2b29df6cab..da96f0d3e753 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1765,11 +1765,6 @@ static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) } #endif -static inline unsigned int skb_data_area_size(struct sk_buff *skb) -{ - return skb_end_pointer(skb) - skb->data; -} - struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, struct ubuf_info *uarg);