net: add skb frag size accessors

To ease skb->truesize sanitization, its better to be able to localize
all references to skb frags size.

Define accessors : skb_frag_size() to fetch frag size, and
skb_frag_size_{set|add|sub}() to manipulate it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 17 insertions, 16 deletions

diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c
index f6821aa5ffb..194a0311380 100644
--- a/drivers/net/ethernet/marvell/mv643xx_eth.c
+++ b/drivers/net/ethernet/marvell/mv643xx_eth.c
@@ -713,8 +713,9 @@ static inline unsigned int has_tiny_unaligned_frags(struct sk_buff *skb)
 	int frag;
 
 	for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
-		skb_frag_t *fragp = &skb_shinfo(skb)->frags[frag];
-		if (fragp->size <= 8 && fragp->page_offset & 7)
+		const skb_frag_t *fragp = &skb_shinfo(skb)->frags[frag];
+
+		if (skb_frag_size(fragp) <= 8 && fragp->page_offset & 7)
 			return 1;
 	}
 
@@ -751,10 +752,10 @@ static void txq_submit_frag_skb(struct tx_queue *txq, struct sk_buff *skb)
 		}
 
 		desc->l4i_chk = 0;
-		desc->byte_cnt = this_frag->size;
+		desc->byte_cnt = skb_frag_size(this_frag);
 		desc->buf_ptr = skb_frag_dma_map(mp->dev->dev.parent,
 						 this_frag, 0,
-						 this_frag->size,
+						 skb_frag_size(this_frag),
 						 DMA_TO_DEVICE);
 	}
 }
diff --git a/drivers/net/ethernet/marvell/skge.c b/drivers/net/ethernet/marvell/skge.c
index 297730359b7..c7b60839ac9 100644
--- a/drivers/net/ethernet/marvell/skge.c
+++ b/drivers/net/ethernet/marvell/skge.c
@@ -2770,10 +2770,10 @@ static netdev_tx_t skge_xmit_frame(struct sk_buff *skb,
 
 		control |= BMU_STFWD;
 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+			const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
 			map = skb_frag_dma_map(&hw->pdev->dev, frag, 0,
-					       frag->size, DMA_TO_DEVICE);
+					       skb_frag_size(frag), DMA_TO_DEVICE);
 
 			e = e->next;
 			e->skb = skb;
@@ -2783,9 +2783,9 @@ static netdev_tx_t skge_xmit_frame(struct sk_buff *skb,
 			tf->dma_lo = map;
 			tf->dma_hi = (u64) map >> 32;
 			dma_unmap_addr_set(e, mapaddr, map);
-			dma_unmap_len_set(e, maplen, frag->size);
+			dma_unmap_len_set(e, maplen, skb_frag_size(frag));
 
-			tf->control = BMU_OWN | BMU_SW | control | frag->size;
+			tf->control = BMU_OWN | BMU_SW | control | skb_frag_size(frag);
 		}
 		tf->control |= BMU_EOF | BMU_IRQ_EOF;
 	}
diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c
index 92634907bf8..7b083c438a1 100644
--- a/drivers/net/ethernet/marvell/sky2.c
+++ b/drivers/net/ethernet/marvell/sky2.c
@@ -1225,10 +1225,10 @@ static int sky2_rx_map_skb(struct pci_dev *pdev, struct rx_ring_info *re,
 	dma_unmap_len_set(re, data_size, size);
 
 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
 		re->frag_addr[i] = skb_frag_dma_map(&pdev->dev, frag, 0,
-						    frag->size,
+						    skb_frag_size(frag),
 						    DMA_FROM_DEVICE);
 
 		if (dma_mapping_error(&pdev->dev, re->frag_addr[i]))
@@ -1239,7 +1239,7 @@ static int sky2_rx_map_skb(struct pci_dev *pdev, struct rx_ring_info *re,
 map_page_error:
 	while (--i >= 0) {
 		pci_unmap_page(pdev, re->frag_addr[i],
-			       skb_shinfo(skb)->frags[i].size,
+			       skb_frag_size(&skb_shinfo(skb)->frags[i]),
 			       PCI_DMA_FROMDEVICE);
 	}
 
@@ -1263,7 +1263,7 @@ static void sky2_rx_unmap_skb(struct pci_dev *pdev, struct rx_ring_info *re)
 
 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
 		pci_unmap_page(pdev, re->frag_addr[i],
-			       skb_shinfo(skb)->frags[i].size,
+			       skb_frag_size(&skb_shinfo(skb)->frags[i]),
 			       PCI_DMA_FROMDEVICE);
 }
 
@@ -1936,7 +1936,7 @@ static netdev_tx_t sky2_xmit_frame(struct sk_buff *skb,
 		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
 		mapping = skb_frag_dma_map(&hw->pdev->dev, frag, 0,
-					   frag->size, DMA_TO_DEVICE);
+					   skb_frag_size(frag), DMA_TO_DEVICE);
 
 		if (dma_mapping_error(&hw->pdev->dev, mapping))
 			goto mapping_unwind;
@@ -1952,11 +1952,11 @@ static netdev_tx_t sky2_xmit_frame(struct sk_buff *skb,
 		re = sky2->tx_ring + slot;
 		re->flags = TX_MAP_PAGE;
 		dma_unmap_addr_set(re, mapaddr, mapping);
-		dma_unmap_len_set(re, maplen, frag->size);
+		dma_unmap_len_set(re, maplen, skb_frag_size(frag));
 
 		le = get_tx_le(sky2, &slot);
 		le->addr = cpu_to_le32(lower_32_bits(mapping));
-		le->length = cpu_to_le16(frag->size);
+		le->length = cpu_to_le16(skb_frag_size(frag));
 		le->ctrl = ctrl;
 		le->opcode = OP_BUFFER | HW_OWNER;
 	}
@@ -2484,7 +2484,7 @@ static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
 		} else {
 			size = min(length, (unsigned) PAGE_SIZE);
 
-			frag->size = size;
+			skb_frag_size_set(frag, size);
 			skb->data_len += size;
 			skb->truesize += PAGE_SIZE;
 			skb->len += size;