bnx2: Handle DMA mapping errors.

Before, the driver would not care about the return codes from pci_map_*
functions.  This could be potentially dangerous if a mapping failed.
Now, we will check all pci_map_* calls.  On the transmit side, we switch
to use the new function skb_dma_map().  On the receive side, we add
pci_dma_mapping_error().

Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 67 insertions, 55 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index f147204e1e47..a95ca4fa249f 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -2476,6 +2476,11 @@ bnx2_alloc_rx_page(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr, u16 index)
                 return -ENOMEM;
         mapping = pci_map_page(bp->pdev, page, 0, PAGE_SIZE,
                                PCI_DMA_FROMDEVICE);
+        if (pci_dma_mapping_error(bp->pdev, mapping)) {
+                __free_page(page);
+                return -EIO;
+        }
+
         rx_pg->page = page;
         pci_unmap_addr_set(rx_pg, mapping, mapping);
         rxbd->rx_bd_haddr_hi = (u64) mapping >> 32;
@@ -2518,6 +2523,10 @@ bnx2_alloc_rx_skb(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr, u16 index)
 
         mapping = pci_map_single(bp->pdev, skb->data, bp->rx_buf_use_size,
                 PCI_DMA_FROMDEVICE);
+        if (pci_dma_mapping_error(bp->pdev, mapping)) {
+                dev_kfree_skb(skb);
+                return -EIO;
+        }
 
         rx_buf->skb = skb;
         pci_unmap_addr_set(rx_buf, mapping, mapping);
@@ -2592,7 +2601,7 @@ bnx2_tx_int(struct bnx2 *bp, struct bnx2_napi *bnapi, int budget)
         sw_cons = txr->tx_cons;
 
         while (sw_cons != hw_cons) {
-                struct sw_bd *tx_buf;
+                struct sw_tx_bd *tx_buf;
                 struct sk_buff *skb;
                 int i, last;
 
@@ -2617,21 +2626,13 @@ bnx2_tx_int(struct bnx2 *bp, struct bnx2_napi *bnapi, int budget)
                         }
                 }
 
-                pci_unmap_single(bp->pdev, pci_unmap_addr(tx_buf, mapping),
-                        skb_headlen(skb), PCI_DMA_TODEVICE);
+                skb_dma_unmap(&bp->pdev->dev, skb, DMA_TO_DEVICE);
 
                 tx_buf->skb = NULL;
                 last = skb_shinfo(skb)->nr_frags;
 
                 for (i = 0; i < last; i++) {
                         sw_cons = NEXT_TX_BD(sw_cons);
-
-                        pci_unmap_page(bp->pdev,
-                                pci_unmap_addr(
-                                        &txr->tx_buf_ring[TX_RING_IDX(sw_cons)],
-                                        mapping),
-                                skb_shinfo(skb)->frags[i].size,
-                                PCI_DMA_TODEVICE);
                 }
 
                 sw_cons = NEXT_TX_BD(sw_cons);
@@ -2672,11 +2673,31 @@ bnx2_reuse_rx_skb_pages(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr,
 {
         struct sw_pg *cons_rx_pg, *prod_rx_pg;
         struct rx_bd *cons_bd, *prod_bd;
-        dma_addr_t mapping;
         int i;
-        u16 hw_prod = rxr->rx_pg_prod, prod;
+        u16 hw_prod, prod;
         u16 cons = rxr->rx_pg_cons;
 
+        cons_rx_pg = &rxr->rx_pg_ring[cons];
+
+        /* The caller was unable to allocate a new page to replace the
+         * last one in the frags array, so we need to recycle that page
+         * and then free the skb.
+         */
+        if (skb) {
+                struct page *page;
+                struct skb_shared_info *shinfo;
+
+                shinfo = skb_shinfo(skb);
+                shinfo->nr_frags--;
+                page = shinfo->frags[shinfo->nr_frags].page;
+                shinfo->frags[shinfo->nr_frags].page = NULL;
+
+                cons_rx_pg->page = page;
+                dev_kfree_skb(skb);
+        }
+
+        hw_prod = rxr->rx_pg_prod;
+
         for (i = 0; i < count; i++) {
                 prod = RX_PG_RING_IDX(hw_prod);
 
@@ -2685,20 +2706,6 @@ bnx2_reuse_rx_skb_pages(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr,
                 cons_bd = &rxr->rx_pg_desc_ring[RX_RING(cons)][RX_IDX(cons)];
                 prod_bd = &rxr->rx_pg_desc_ring[RX_RING(prod)][RX_IDX(prod)];
 
-                if (i == 0 && skb) {
-                        struct page *page;
-                        struct skb_shared_info *shinfo;
-
-                        shinfo = skb_shinfo(skb);
-                        shinfo->nr_frags--;
-                        page = shinfo->frags[shinfo->nr_frags].page;
-                        shinfo->frags[shinfo->nr_frags].page = NULL;
-                        mapping = pci_map_page(bp->pdev, page, 0, PAGE_SIZE,
-                                               PCI_DMA_FROMDEVICE);
-                        cons_rx_pg->page = page;
-                        pci_unmap_addr_set(cons_rx_pg, mapping, mapping);
-                        dev_kfree_skb(skb);
-                }
                 if (prod != cons) {
                         prod_rx_pg->page = cons_rx_pg->page;
                         cons_rx_pg->page = NULL;
@@ -2784,6 +2791,8 @@ bnx2_rx_skb(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr, struct sk_buff *skb,
                 skb_put(skb, hdr_len);
 
                 for (i = 0; i < pages; i++) {
+                        dma_addr_t mapping_old;
+
                         frag_len = min(frag_size, (unsigned int) PAGE_SIZE);
                         if (unlikely(frag_len <= 4)) {
                                 unsigned int tail = 4 - frag_len;
@@ -2806,9 +2815,10 @@ bnx2_rx_skb(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr, struct sk_buff *skb,
                         }
                         rx_pg = &rxr->rx_pg_ring[pg_cons];
 
-                        pci_unmap_page(bp->pdev, pci_unmap_addr(rx_pg, mapping),
-                                       PAGE_SIZE, PCI_DMA_FROMDEVICE);
-
+                        /* Don't unmap yet.  If we're unable to allocate a new
+                         * page, we need to recycle the page and the DMA addr.
+                         */
+                        mapping_old = pci_unmap_addr(rx_pg, mapping);
                         if (i == pages - 1)
                                 frag_len -= 4;
 
@@ -2825,6 +2835,9 @@ bnx2_rx_skb(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr, struct sk_buff *skb,
                                 return err;
                         }
 
+                        pci_unmap_page(bp->pdev, mapping_old,
+                                       PAGE_SIZE, PCI_DMA_FROMDEVICE);
+
                         frag_size -= frag_len;
                         skb->data_len += frag_len;
                         skb->truesize += frag_len;
@@ -4971,31 +4984,20 @@ bnx2_free_tx_skbs(struct bnx2 *bp)
                         continue;
 
                 for (j = 0; j < TX_DESC_CNT; ) {
-                        struct sw_bd *tx_buf = &txr->tx_buf_ring[j];
+                        struct sw_tx_bd *tx_buf = &txr->tx_buf_ring[j];
                         struct sk_buff *skb = tx_buf->skb;
-                        int k, last;
 
                         if (skb == NULL) {
                                 j++;
                                 continue;
                         }
 
-                        pci_unmap_single(bp->pdev,
-                                         pci_unmap_addr(tx_buf, mapping),
-                        skb_headlen(skb), PCI_DMA_TODEVICE);
+                        skb_dma_unmap(&bp->pdev->dev, skb, DMA_TO_DEVICE);
 
                         tx_buf->skb = NULL;
 
-                        last = skb_shinfo(skb)->nr_frags;
-                        for (k = 0; k < last; k++) {
-                                tx_buf = &txr->tx_buf_ring[j + k + 1];
-                                pci_unmap_page(bp->pdev,
-                                        pci_unmap_addr(tx_buf, mapping),
-                                        skb_shinfo(skb)->frags[j].size,
-                                        PCI_DMA_TODEVICE);
-                        }
+                        j += skb_shinfo(skb)->nr_frags + 1;
                         dev_kfree_skb(skb);
-                        j += k + 1;
                 }
         }
 }
@@ -5373,8 +5375,11 @@ bnx2_run_loopback(struct bnx2 *bp, int loopback_mode)
         for (i = 14; i < pkt_size; i++)
                 packet[i] = (unsigned char) (i & 0xff);
 
-        map = pci_map_single(bp->pdev, skb->data, pkt_size,
-                PCI_DMA_TODEVICE);
+        if (skb_dma_map(&bp->pdev->dev, skb, DMA_TO_DEVICE)) {
+                dev_kfree_skb(skb);
+                return -EIO;
+        }
+        map = skb_shinfo(skb)->dma_maps[0];
 
         REG_WR(bp, BNX2_HC_COMMAND,
                bp->hc_cmd | BNX2_HC_COMMAND_COAL_NOW_WO_INT);
@@ -5409,7 +5414,7 @@ bnx2_run_loopback(struct bnx2 *bp, int loopback_mode)
 
         udelay(5);
 
-        pci_unmap_single(bp->pdev, map, pkt_size, PCI_DMA_TODEVICE);
+        skb_dma_unmap(&bp->pdev->dev, skb, DMA_TO_DEVICE);
         dev_kfree_skb(skb);
 
         if (bnx2_get_hw_tx_cons(tx_napi) != txr->tx_prod)
@@ -5970,13 +5975,14 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device *dev)
         struct bnx2 *bp = netdev_priv(dev);
         dma_addr_t mapping;
         struct tx_bd *txbd;
-        struct sw_bd *tx_buf;
+        struct sw_tx_bd *tx_buf;
         u32 len, vlan_tag_flags, last_frag, mss;
         u16 prod, ring_prod;
         int i;
         struct bnx2_napi *bnapi;
         struct bnx2_tx_ring_info *txr;
         struct netdev_queue *txq;
+        struct skb_shared_info *sp;
 
         /*  Determine which tx ring we will be placed on */
         i = skb_get_queue_mapping(skb);
@@ -6041,11 +6047,16 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device *dev)
         } else
                 mss = 0;
 
-        mapping = pci_map_single(bp->pdev, skb->data, len, PCI_DMA_TODEVICE);
+        if (skb_dma_map(&bp->pdev->dev, skb, DMA_TO_DEVICE)) {
+                dev_kfree_skb(skb);
+                return NETDEV_TX_OK;
+        }
+
+        sp = skb_shinfo(skb);
+        mapping = sp->dma_maps[0];
 
         tx_buf = &txr->tx_buf_ring[ring_prod];
         tx_buf->skb = skb;
-        pci_unmap_addr_set(tx_buf, mapping, mapping);
 
         txbd = &txr->tx_desc_ring[ring_prod];
 
@@ -6064,10 +6075,7 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 txbd = &txr->tx_desc_ring[ring_prod];
 
                 len = frag->size;
-                mapping = pci_map_page(bp->pdev, frag->page, frag->page_offset,
-                        len, PCI_DMA_TODEVICE);
-                pci_unmap_addr_set(&txr->tx_buf_ring[ring_prod],
-                                mapping, mapping);
+                mapping = sp->dma_maps[i + 1];
 
                 txbd->tx_bd_haddr_hi = (u64) mapping >> 32;
                 txbd->tx_bd_haddr_lo = (u64) mapping & 0xffffffff;
diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index edc7774f2f21..617d95340160 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -6526,10 +6526,14 @@ struct sw_pg {
         DECLARE_PCI_UNMAP_ADDR(mapping)
 };
 
+struct sw_tx_bd {
+        struct sk_buff          *skb;
+};
+
 #define SW_RXBD_RING_SIZE (sizeof(struct sw_bd) * RX_DESC_CNT)
 #define SW_RXPG_RING_SIZE (sizeof(struct sw_pg) * RX_DESC_CNT)
 #define RXBD_RING_SIZE (sizeof(struct rx_bd) * RX_DESC_CNT)
-#define SW_TXBD_RING_SIZE (sizeof(struct sw_bd) * TX_DESC_CNT)
+#define SW_TXBD_RING_SIZE (sizeof(struct sw_tx_bd) * TX_DESC_CNT)
 #define TXBD_RING_SIZE (sizeof(struct tx_bd) * TX_DESC_CNT)
 
 /* Buffered flash (Atmel: AT45DB011B) specific information */
@@ -6609,7 +6613,7 @@ struct bnx2_tx_ring_info {
         u32                     tx_bseq_addr;
 
         struct tx_bd            *tx_desc_ring;
-        struct sw_bd            *tx_buf_ring;
+        struct sw_tx_bd         *tx_buf_ring;
 
         u16                     tx_cons;
         u16                     hw_tx_cons;