Merge branch 'mlx4'

Amir Vadai says:

====================
net/mlx4_en: Fix pages never dma unmapped on rx

This patchset fixes a bug introduced by commit 51151a16 (mlx4: allow order-0
memory allocations in RX path). Where dma_unmap_page wasn't called.

Changes from V0:
- Added "Rename name of mlx4_en_rx_alloc members". Old names were confusing.
- Last frag in page calculation was wrong. Since all frags in page are of the
  same size, need to add this frag_stride to end of frag offset, and not the
  size of next frag in skb.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 26 insertions, 19 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index dec455c8f627..afe2efa69c86 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -70,14 +70,15 @@ static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
                 put_page(page);
                 return -ENOMEM;
         }
-        page_alloc->size = PAGE_SIZE << order;
+        page_alloc->page_size = PAGE_SIZE << order;
         page_alloc->page = page;
         page_alloc->dma = dma;
-        page_alloc->offset = frag_info->frag_align;
+        page_alloc->page_offset = frag_info->frag_align;
         /* Not doing get_page() for each frag is a big win
          * on asymetric workloads.
          */
-        atomic_set(&page->_count, page_alloc->size / frag_info->frag_stride);
+        atomic_set(&page->_count,
+                   page_alloc->page_size / frag_info->frag_stride);
         return 0;
 }
 
@@ -96,16 +97,19 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
         for (i = 0; i < priv->num_frags; i++) {
                 frag_info = &priv->frag_info[i];
                 page_alloc[i] = ring_alloc[i];
-                page_alloc[i].offset += frag_info->frag_stride;
-                if (page_alloc[i].offset + frag_info->frag_stride <= ring_alloc[i].size)
+                page_alloc[i].page_offset += frag_info->frag_stride;
+
+                if (page_alloc[i].page_offset + frag_info->frag_stride <=
+                    ring_alloc[i].page_size)
                         continue;
+
                 if (mlx4_alloc_pages(priv, &page_alloc[i], frag_info, gfp))
                         goto out;
         }
 
         for (i = 0; i < priv->num_frags; i++) {
                 frags[i] = ring_alloc[i];
-                dma = ring_alloc[i].dma + ring_alloc[i].offset;
+                dma = ring_alloc[i].dma + ring_alloc[i].page_offset;
                 ring_alloc[i] = page_alloc[i];
                 rx_desc->data[i].addr = cpu_to_be64(dma);
         }
@@ -117,7 +121,7 @@ out:
                 frag_info = &priv->frag_info[i];
                 if (page_alloc[i].page != ring_alloc[i].page) {
                         dma_unmap_page(priv->ddev, page_alloc[i].dma,
-                                page_alloc[i].size, PCI_DMA_FROMDEVICE);
+                                page_alloc[i].page_size, PCI_DMA_FROMDEVICE);
                         page = page_alloc[i].page;
                         atomic_set(&page->_count, 1);
                         put_page(page);
@@ -131,10 +135,12 @@ static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
                               int i)
 {
         const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
+        u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride;
+
 
-        if (frags[i].offset + frag_info->frag_stride > frags[i].size)
-                dma_unmap_page(priv->ddev, frags[i].dma, frags[i].size,
-                                         PCI_DMA_FROMDEVICE);
+        if (next_frag_end > frags[i].page_size)
+                dma_unmap_page(priv->ddev, frags[i].dma, frags[i].page_size,
+                               PCI_DMA_FROMDEVICE);
 
         if (frags[i].page)
                 put_page(frags[i].page);
@@ -161,7 +167,7 @@ out:
 
                 page_alloc = &ring->page_alloc[i];
                 dma_unmap_page(priv->ddev, page_alloc->dma,
-                               page_alloc->size, PCI_DMA_FROMDEVICE);
+                               page_alloc->page_size, PCI_DMA_FROMDEVICE);
                 page = page_alloc->page;
                 atomic_set(&page->_count, 1);
                 put_page(page);
@@ -184,10 +190,11 @@ static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
                        i, page_count(page_alloc->page));
 
                 dma_unmap_page(priv->ddev, page_alloc->dma,
-                                page_alloc->size, PCI_DMA_FROMDEVICE);
-                while (page_alloc->offset + frag_info->frag_stride < page_alloc->size) {
+                                page_alloc->page_size, PCI_DMA_FROMDEVICE);
+                while (page_alloc->page_offset + frag_info->frag_stride <
+                       page_alloc->page_size) {
                         put_page(page_alloc->page);
-                        page_alloc->offset += frag_info->frag_stride;
+                        page_alloc->page_offset += frag_info->frag_stride;
                 }
                 page_alloc->page = NULL;
         }
@@ -478,7 +485,7 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
                 /* Save page reference in skb */
                 __skb_frag_set_page(&skb_frags_rx[nr], frags[nr].page);
                 skb_frag_size_set(&skb_frags_rx[nr], frag_info->frag_size);
-                skb_frags_rx[nr].page_offset = frags[nr].offset;
+                skb_frags_rx[nr].page_offset = frags[nr].page_offset;
                 skb->truesize += frag_info->frag_stride;
                 frags[nr].page = NULL;
         }
@@ -517,7 +524,7 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
 
         /* Get pointer to first fragment so we could copy the headers into the
          * (linear part of the) skb */
-        va = page_address(frags[0].page) + frags[0].offset;
+        va = page_address(frags[0].page) + frags[0].page_offset;
 
         if (length <= SMALL_PACKET_SIZE) {
                 /* We are copying all relevant data to the skb - temporarily
@@ -645,7 +652,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
                         dma_sync_single_for_cpu(priv->ddev, dma, sizeof(*ethh),
                                                 DMA_FROM_DEVICE);
                         ethh = (struct ethhdr *)(page_address(frags[0].page) +
-                                                 frags[0].offset);
+                                                 frags[0].page_offset);
 
                         if (is_multicast_ether_addr(ethh->h_dest)) {
                                 struct mlx4_mac_entry *entry;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 5e0aa569306a..bf06e3610d27 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -237,8 +237,8 @@ struct mlx4_en_tx_desc {
 struct mlx4_en_rx_alloc {
         struct page     *page;
         dma_addr_t      dma;
-        u32             offset;
-        u32             size;
+        u32             page_offset;
+        u32             page_size;
 };
 
 struct mlx4_en_tx_ring {