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 f6821aa5ffbf..194a03113802 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 297730359b79..c7b60839ac99 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 92634907bf8d..7b083c438a14 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;