tg3: remove unnecessary read of PCI_CAP_ID_EXP

The PCIE capability offset is saved during PCI bus walking.  Use the
value from pci_dev instead of checking in the driver and saving it off
the the driver specific structure.  It will remove an unnecessary search
in the PCI configuration space if this value is referenced instead of
reacquiring it.

v2 of the patch re-adds the PCI_EXPRESS flag and adds comments
describing why it is necessary.

[ pdev->pcie_cap --> pci_pcie_cap(pdev) -DaveM ]

Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 97cd02d..8211b9a 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -2679,11 +2679,11 @@
 		u16 lnkctl;
 
 		pci_read_config_word(tp->pdev,
-				     tp->pcie_cap + PCI_EXP_LNKCTL,
+				     pci_pcie_cap(tp->pdev) + PCI_EXP_LNKCTL,
 				     &lnkctl);
 		lnkctl |= PCI_EXP_LNKCTL_CLKREQ_EN;
 		pci_write_config_word(tp->pdev,
-				      tp->pcie_cap + PCI_EXP_LNKCTL,
+				      pci_pcie_cap(tp->pdev) + PCI_EXP_LNKCTL,
 				      lnkctl);
 	}
 
@@ -3485,7 +3485,7 @@
 		u16 oldlnkctl, newlnkctl;
 
 		pci_read_config_word(tp->pdev,
-				     tp->pcie_cap + PCI_EXP_LNKCTL,
+				     pci_pcie_cap(tp->pdev) + PCI_EXP_LNKCTL,
 				     &oldlnkctl);
 		if (tp->link_config.active_speed == SPEED_100 ||
 		    tp->link_config.active_speed == SPEED_10)
@@ -3494,7 +3494,7 @@
 			newlnkctl = oldlnkctl | PCI_EXP_LNKCTL_CLKREQ_EN;
 		if (newlnkctl != oldlnkctl)
 			pci_write_config_word(tp->pdev,
-					      tp->pcie_cap + PCI_EXP_LNKCTL,
+					      pci_pcie_cap(tp->pdev) + PCI_EXP_LNKCTL,
 					      newlnkctl);
 	}
 
@@ -7226,7 +7226,7 @@
 
 	udelay(120);
 
-	if (tg3_flag(tp, PCI_EXPRESS) && tp->pcie_cap) {
+	if (tg3_flag(tp, PCI_EXPRESS) && pci_pcie_cap(tp->pdev)) {
 		u16 val16;
 
 		if (tp->pci_chip_rev_id == CHIPREV_ID_5750_A0) {
@@ -7244,7 +7244,7 @@
 
 		/* Clear the "no snoop" and "relaxed ordering" bits. */
 		pci_read_config_word(tp->pdev,
-				     tp->pcie_cap + PCI_EXP_DEVCTL,
+				     pci_pcie_cap(tp->pdev) + PCI_EXP_DEVCTL,
 				     &val16);
 		val16 &= ~(PCI_EXP_DEVCTL_RELAX_EN |
 			   PCI_EXP_DEVCTL_NOSNOOP_EN);
@@ -7255,14 +7255,14 @@
 		if (!tg3_flag(tp, CPMU_PRESENT))
 			val16 &= ~PCI_EXP_DEVCTL_PAYLOAD;
 		pci_write_config_word(tp->pdev,
-				      tp->pcie_cap + PCI_EXP_DEVCTL,
+				      pci_pcie_cap(tp->pdev) + PCI_EXP_DEVCTL,
 				      val16);
 
 		pcie_set_readrq(tp->pdev, tp->pcie_readrq);
 
 		/* Clear error status */
 		pci_write_config_word(tp->pdev,
-				      tp->pcie_cap + PCI_EXP_DEVSTA,
+				      pci_pcie_cap(tp->pdev) + PCI_EXP_DEVSTA,
 				      PCI_EXP_DEVSTA_CED |
 				      PCI_EXP_DEVSTA_NFED |
 				      PCI_EXP_DEVSTA_FED |
@@ -13777,8 +13777,7 @@
 	pci_read_config_dword(tp->pdev, TG3PCI_PCISTATE,
 			      &pci_state_reg);
 
-	tp->pcie_cap = pci_find_capability(tp->pdev, PCI_CAP_ID_EXP);
-	if (tp->pcie_cap != 0) {
+	if (pci_is_pcie(tp->pdev)) {
 		u16 lnkctl;
 
 		tg3_flag_set(tp, PCI_EXPRESS);
@@ -13791,7 +13790,7 @@
 		pcie_set_readrq(tp->pdev, tp->pcie_readrq);
 
 		pci_read_config_word(tp->pdev,
-				     tp->pcie_cap + PCI_EXP_LNKCTL,
+				     pci_pcie_cap(tp->pdev) + PCI_EXP_LNKCTL,
 				     &lnkctl);
 		if (lnkctl & PCI_EXP_LNKCTL_CLKREQ_EN) {
 			if (GET_ASIC_REV(tp->pci_chip_rev_id) ==
@@ -13808,6 +13807,10 @@
 			tg3_flag_set(tp, L1PLLPD_EN);
 		}
 	} else if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5785) {
+		/* BCM5785 devices are effectively PCIe devices, and should
+		 * follow PCIe codepaths, but do not have a PCIe capabilities
+		 * section.
+		*/
 		tg3_flag_set(tp, PCI_EXPRESS);
 	} else if (!tg3_flag(tp, 5705_PLUS) ||
 		   tg3_flag(tp, 5780_CLASS)) {
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index bedc3b4..5f250ae 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2857,7 +2857,7 @@
 	TG3_FLAG_IS_5788,
 	TG3_FLAG_MAX_RXPEND_64,
 	TG3_FLAG_TSO_CAPABLE,
-	TG3_FLAG_PCI_EXPRESS,
+	TG3_FLAG_PCI_EXPRESS, /* BCM5785 + pci_is_pcie() */
 	TG3_FLAG_ASF_NEW_HANDSHAKE,
 	TG3_FLAG_HW_AUTONEG,
 	TG3_FLAG_IS_NIC,
@@ -3022,10 +3022,7 @@
 
 	int				pm_cap;
 	int				msi_cap;
-	union {
 	int				pcix_cap;
-	int				pcie_cap;
-	};
 	int				pcie_readrq;
 
 	struct mii_bus			*mdio_bus;