nui: Fix dma_mapping_error() check

dma_map_XXX() functions return values DMA_MAPPING_ERROR as error values
which is often ~0.  The error value should be tested with
dma_mapping_error().

This patch creates a new function in niu_ops to test if the mapping
failed.  The test is fixed in niu_rbr_add_page(), added in
niu_start_xmit() and the successfully mapped pages are unmaped upon error.

Fixes: ec2deec1f352 ("niu: Fix to check for dma mapping errors.")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sun/niu.c b/drivers/net/ethernet/sun/niu.c
index ddca8fc7883eda13acbe4e853cd071da38b004b3..26119d02a94d2fd19afd4aa16b2195c13c3d9c11 100644 (file)
--- a/drivers/net/ethernet/sun/niu.c
+++ b/drivers/net/ethernet/sun/niu.c
@@ -3336,7 +3336,7 @@ static int niu_rbr_add_page(struct niu *np, struct rx_ring_info *rp,
 
        addr = np->ops->map_page(np->device, page, 0,
                                 PAGE_SIZE, DMA_FROM_DEVICE);
-       if (!addr) {
+       if (np->ops->mapping_error(np->device, addr)) {
                __free_page(page);
                return -ENOMEM;
        }
@@ -6676,6 +6676,8 @@ static netdev_tx_t niu_start_xmit(struct sk_buff *skb,
        len = skb_headlen(skb);
        mapping = np->ops->map_single(np->device, skb->data,
                                      len, DMA_TO_DEVICE);
+       if (np->ops->mapping_error(np->device, mapping))
+               goto out_drop;
 
        prod = rp->prod;
 
@@ -6717,6 +6719,8 @@ static netdev_tx_t niu_start_xmit(struct sk_buff *skb,
                mapping = np->ops->map_page(np->device, skb_frag_page(frag),
                                            skb_frag_off(frag), len,
                                            DMA_TO_DEVICE);
+               if (np->ops->mapping_error(np->device, mapping))
+                       goto out_unmap;
 
                rp->tx_buffs[prod].skb = NULL;
                rp->tx_buffs[prod].mapping = mapping;
@@ -6741,6 +6745,19 @@ static netdev_tx_t niu_start_xmit(struct sk_buff *skb,
 out:
        return NETDEV_TX_OK;
 
+out_unmap:
+       while (i--) {
+               const skb_frag_t *frag;
+
+               prod = PREVIOUS_TX(rp, prod);
+               frag = &skb_shinfo(skb)->frags[i];
+               np->ops->unmap_page(np->device, rp->tx_buffs[prod].mapping,
+                                   skb_frag_size(frag), DMA_TO_DEVICE);
+       }
+
+       np->ops->unmap_single(np->device, rp->tx_buffs[rp->prod].mapping,
+                             skb_headlen(skb), DMA_TO_DEVICE);
+
 out_drop:
        rp->tx_errors++;
        kfree_skb(skb);
@@ -9644,6 +9661,11 @@ static void niu_pci_unmap_single(struct device *dev, u64 dma_address,
        dma_unmap_single(dev, dma_address, size, direction);
 }
 
+static int niu_pci_mapping_error(struct device *dev, u64 addr)
+{
+       return dma_mapping_error(dev, addr);
+}
+
 static const struct niu_ops niu_pci_ops = {
        .alloc_coherent = niu_pci_alloc_coherent,
        .free_coherent  = niu_pci_free_coherent,
@@ -9651,6 +9673,7 @@ static const struct niu_ops niu_pci_ops = {
        .unmap_page     = niu_pci_unmap_page,
        .map_single     = niu_pci_map_single,
        .unmap_single   = niu_pci_unmap_single,
+       .mapping_error  = niu_pci_mapping_error,
 };
 
 static void niu_driver_version(void)
@@ -10019,6 +10042,11 @@ static void niu_phys_unmap_single(struct device *dev, u64 dma_address,
        /* Nothing to do.  */
 }
 
+static int niu_phys_mapping_error(struct device *dev, u64 dma_address)
+{
+       return false;
+}
+
 static const struct niu_ops niu_phys_ops = {
        .alloc_coherent = niu_phys_alloc_coherent,
        .free_coherent  = niu_phys_free_coherent,
@@ -10026,6 +10054,7 @@ static const struct niu_ops niu_phys_ops = {
        .unmap_page     = niu_phys_unmap_page,
        .map_single     = niu_phys_map_single,
        .unmap_single   = niu_phys_unmap_single,
+       .mapping_error  = niu_phys_mapping_error,
 };
 
 static int niu_of_probe(struct platform_device *op)

diff --git a/drivers/net/ethernet/sun/niu.h b/drivers/net/ethernet/sun/niu.h
index 04c215f91fc08e004c4781feb646d7cd4b1e8f83..0b169c08b0f2d1001a9f56bad4fae24debe9c330 100644 (file)
--- a/drivers/net/ethernet/sun/niu.h
+++ b/drivers/net/ethernet/sun/niu.h
@@ -2879,6 +2879,9 @@ struct tx_ring_info {
 #define NEXT_TX(tp, index) \
        (((index) + 1) < (tp)->pending ? ((index) + 1) : 0)
 
+#define PREVIOUS_TX(tp, index) \
+       (((index) - 1) >= 0 ? ((index) - 1) : (((tp)->pending) - 1))
+
 static inline u32 niu_tx_avail(struct tx_ring_info *tp)
 {
        return (tp->pending -
@@ -3140,6 +3143,7 @@ struct niu_ops {
                          enum dma_data_direction direction);
        void (*unmap_single)(struct device *dev, u64 dma_address,
                             size_t size, enum dma_data_direction direction);
+       int (*mapping_error)(struct device *dev, u64 dma_address);
 };
 
 struct niu_link_config {