tg3: Add partial fragment unmapping code

The following patches are going to break skb fragments into smaller
sizes.  This patch attempts to make the change easier to digest by only
addressing the skb teardown portion.

The patch modifies the driver to skip over any BDs that have a flag set
that indicates the BD isn't the beginning of an skb fragment.  Such BDs
were a result of segmentation and do not need a pci_unmap_page() call.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e01ee14d499e5d09c0a9db0cac2545a018849e3d)

Signed-off-by: Joe Jin <joe.jin@oracle.com>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 4db20cb0b02fb3c0b976d1abbca3998a9d1b077c..58e7d59a0b78970f261dcfdfd5670fc36d9678a6 100644 (file)
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -4839,6 +4839,12 @@ static void tg3_tx(struct tg3_napi *tnapi)
 
                ri->skb = NULL;
 
+               while (ri->fragmented) {
+                       ri->fragmented = false;
+                       sw_idx = NEXT_TX(sw_idx);
+                       ri = &tnapi->tx_buffers[sw_idx];
+               }
+
                sw_idx = NEXT_TX(sw_idx);
 
                for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
@@ -4850,6 +4856,13 @@ static void tg3_tx(struct tg3_napi *tnapi)
                                       dma_unmap_addr(ri, mapping),
                                       skb_shinfo(skb)->frags[i].size,
                                       PCI_DMA_TODEVICE);
+
+                       while (ri->fragmented) {
+                               ri->fragmented = false;
+                               sw_idx = NEXT_TX(sw_idx);
+                               ri = &tnapi->tx_buffers[sw_idx];
+                       }
+
                        sw_idx = NEXT_TX(sw_idx);
                }
 
@@ -5932,6 +5945,13 @@ static void tg3_tx_skb_unmap(struct tg3_napi *tnapi, u32 entry, int last)
                         dma_unmap_addr(txb, mapping),
                         skb_headlen(skb),
                         PCI_DMA_TODEVICE);
+
+       while (txb->fragmented) {
+               txb->fragmented = false;
+               entry = NEXT_TX(entry);
+               txb = &tnapi->tx_buffers[entry];
+       }
+
        for (i = 0; i < last; i++) {
                skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
@@ -5941,6 +5961,12 @@ static void tg3_tx_skb_unmap(struct tg3_napi *tnapi, u32 entry, int last)
                pci_unmap_page(tnapi->tp->pdev,
                               dma_unmap_addr(txb, mapping),
                               frag->size, PCI_DMA_TODEVICE);
+
+               while (txb->fragmented) {
+                       txb->fragmented = false;
+                       entry = NEXT_TX(entry);
+                       txb = &tnapi->tx_buffers[entry];
+               }
        }
 }
 

diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 27826a536de85b643ab35fe2ade6252d8e7bb541..1cba0905a386cc706a9c3fe2cf04a909160aa833 100644 (file)
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2655,6 +2655,7 @@ struct ring_info {
 struct tg3_tx_ring_info {
        struct sk_buff                  *skb;
        DEFINE_DMA_UNMAP_ADDR(mapping);
+       bool                            fragmented;
 };
 
 struct tg3_link_config {