tg3: 5701 DMA corruption fix

Herbert Xu's commit fb93134dfc2a6e6fbedc7c270a31da03fce88db9, entitled
"[TCP]: Fix size calculation in sk_stream_alloc_pskb", has triggered a
bug in the 5701 where the 5701 DMA engine will corrupt outgoing
packets.  This problem only happens when the starting address of the
packet matches a certain range of offsets and only when the 5701 is
placed downstream of a particular Intel bridge.

This patch detects the problematic bridge and if present, readjusts the
starting address of the packet data to a dword aligned boundary.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 96043c5746d00a44977a402ccb60238a0a842fcc..bc4c62b8e81a4d7be3441bdc578daf3689646ab2 100644 (file)
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -64,8 +64,8 @@
 
 #define DRV_MODULE_NAME                "tg3"
 #define PFX DRV_MODULE_NAME    ": "
-#define DRV_MODULE_VERSION     "3.90"
-#define DRV_MODULE_RELDATE     "April 12, 2008"
+#define DRV_MODULE_VERSION     "3.91"
+#define DRV_MODULE_RELDATE     "April 18, 2008"
 
 #define TG3_DEF_MAC_MODE       0
 #define TG3_DEF_RX_MODE                0
@@ -4135,11 +4135,21 @@ static int tigon3_dma_hwbug_workaround(struct tg3 *tp, struct sk_buff *skb,
                                       u32 last_plus_one, u32 *start,
                                       u32 base_flags, u32 mss)
 {
-       struct sk_buff *new_skb = skb_copy(skb, GFP_ATOMIC);
+       struct sk_buff *new_skb;
        dma_addr_t new_addr = 0;
        u32 entry = *start;
        int i, ret = 0;
 
+       if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701)
+               new_skb = skb_copy(skb, GFP_ATOMIC);
+       else {
+               int more_headroom = 4 - ((unsigned long)skb->data & 3);
+
+               new_skb = skb_copy_expand(skb,
+                                         skb_headroom(skb) + more_headroom,
+                                         skb_tailroom(skb), GFP_ATOMIC);
+       }
+
        if (!new_skb) {
                ret = -1;
        } else {
@@ -4462,7 +4472,9 @@ static int tg3_start_xmit_dma_bug(struct sk_buff *skb, struct net_device *dev)
 
        would_hit_hwbug = 0;
 
-       if (tg3_4g_overflow_test(mapping, len))
+       if (tp->tg3_flags3 & TG3_FLG3_5701_DMA_BUG)
+               would_hit_hwbug = 1;
+       else if (tg3_4g_overflow_test(mapping, len))
                would_hit_hwbug = 1;
 
        tg3_set_txd(tp, entry, mapping, len, base_flags,
@@ -11339,6 +11351,38 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
                }
        }
 
+       if ((GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5701)) {
+               static struct tg3_dev_id {
+                       u32     vendor;
+                       u32     device;
+               } bridge_chipsets[] = {
+                       { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_PXH_0 },
+                       { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_PXH_1 },
+                       { },
+               };
+               struct tg3_dev_id *pci_id = &bridge_chipsets[0];
+               struct pci_dev *bridge = NULL;
+
+               while (pci_id->vendor != 0) {
+                       bridge = pci_get_device(pci_id->vendor,
+                                               pci_id->device,
+                                               bridge);
+                       if (!bridge) {
+                               pci_id++;
+                               continue;
+                       }
+                       if (bridge->subordinate &&
+                           (bridge->subordinate->number <=
+                            tp->pdev->bus->number) &&
+                           (bridge->subordinate->subordinate >=
+                            tp->pdev->bus->number)) {
+                               tp->tg3_flags3 |= TG3_FLG3_5701_DMA_BUG;
+                               pci_dev_put(bridge);
+                               break;
+                       }
+               }
+       }
+
        /* The EPB bridge inside 5714, 5715, and 5780 cannot support
         * DMA addresses > 40-bit. This bridge may have other additional
         * 57xx devices behind it in some 4-port NIC designs for example.

diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index c1075a73d66c08dba2c6132113939a2a23e52f21..c688c3ac5035ed0db7feccb896a15df45a316832 100644 (file)
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2476,6 +2476,7 @@ struct tg3 {
 #define TG3_FLG3_NO_NVRAM_ADDR_TRANS   0x00000001
 #define TG3_FLG3_ENABLE_APE            0x00000002
 #define TG3_FLG3_5761_5784_AX_FIXES    0x00000004
+#define TG3_FLG3_5701_DMA_BUG          0x00000008
 
        struct timer_list               timer;
        u16                             timer_counter;