igb: add completion timeout workaround for 82575/82576

The 82575 and 82576 hardware can both experience data corruption issues if
a pci-e completion arrives after the timeout value.  In order to avoid this
we need to increase the timeout value while pci-e master is disabled.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/igb/e1000_82575.c

@@ -61,6 +61,7 @@ static void igb_release_swfw_sync_82575(struct e1000_hw *, u16);
 static bool igb_sgmii_active_82575(struct e1000_hw *);
 static s32  igb_reset_init_script_82575(struct e1000_hw *);
 static s32  igb_read_mac_addr_82575(struct e1000_hw *);
+static s32  igb_set_pcie_completion_timeout(struct e1000_hw *hw);
 
 static s32 igb_get_invariants_82575(struct e1000_hw *hw)
 {
@@ -909,6 +910,12 @@ static s32 igb_reset_hw_82575(struct e1000_hw *hw)
 	if (ret_val)
 		hw_dbg("PCI-E Master disable polling has failed.\n");
 
+	/* set the completion timeout for interface */
+	ret_val = igb_set_pcie_completion_timeout(hw);
+	if (ret_val) {
+		hw_dbg("PCI-E Set completion timeout has failed.\n");
+	}
+
 	hw_dbg("Masking off all interrupts\n");
 	wr32(E1000_IMC, 0xffffffff);
 
@@ -1407,6 +1414,57 @@ void igb_rx_fifo_flush_82575(struct e1000_hw *hw)
 	rd32(E1000_MPC);
 }
 
+/**
+ *  igb_set_pcie_completion_timeout - set pci-e completion timeout
+ *  @hw: pointer to the HW structure
+ *
+ *  The defaults for 82575 and 82576 should be in the range of 50us to 50ms,
+ *  however the hardware default for these parts is 500us to 1ms which is less
+ *  than the 10ms recommended by the pci-e spec.  To address this we need to
+ *  increase the value to either 10ms to 200ms for capability version 1 config,
+ *  or 16ms to 55ms for version 2.
+ **/
+static s32 igb_set_pcie_completion_timeout(struct e1000_hw *hw)
+{
+	u32 gcr = rd32(E1000_GCR);
+	s32 ret_val = 0;
+	u16 pcie_devctl2;
+
+	/* only take action if timeout value is defaulted to 0 */
+	if (gcr & E1000_GCR_CMPL_TMOUT_MASK)
+		goto out;
+
+	/*
+	 * if capababilities version is type 1 we can write the
+	 * timeout of 10ms to 200ms through the GCR register
+	 */
+	if (!(gcr & E1000_GCR_CAP_VER2)) {
+		gcr |= E1000_GCR_CMPL_TMOUT_10ms;
+		goto out;
+	}
+
+	/*
+	 * for version 2 capabilities we need to write the config space
+	 * directly in order to set the completion timeout value for
+	 * 16ms to 55ms
+	 */
+	ret_val = igb_read_pcie_cap_reg(hw, PCIE_DEVICE_CONTROL2,
+	                                &pcie_devctl2);
+	if (ret_val)
+		goto out;
+
+	pcie_devctl2 |= PCIE_DEVICE_CONTROL2_16ms;
+
+	ret_val = igb_write_pcie_cap_reg(hw, PCIE_DEVICE_CONTROL2,
+	                                 &pcie_devctl2);
+out:
+	/* disable completion timeout resend */
+	gcr &= ~E1000_GCR_CMPL_TMOUT_RESEND;
+
+	wr32(E1000_GCR, gcr);
+	return ret_val;
+}
+
 /**
  *  igb_vmdq_set_loopback_pf - enable or disable vmdq loopback
  *  @hw: pointer to the hardware struct

drivers/net/igb/e1000_defines.h

@@ -435,6 +435,12 @@
 /* Flow Control */
 #define E1000_FCRTL_XONE 0x80000000     /* Enable XON frame transmission */
 
+/* PCI Express Control */
+#define E1000_GCR_CMPL_TMOUT_MASK       0x0000F000
+#define E1000_GCR_CMPL_TMOUT_10ms       0x00001000
+#define E1000_GCR_CMPL_TMOUT_RESEND     0x00010000
+#define E1000_GCR_CAP_VER2              0x00040000
+
 /* PHY Control Register */
 #define MII_CR_FULL_DUPLEX      0x0100  /* FDX =1, half duplex =0 */
 #define MII_CR_RESTART_AUTO_NEG 0x0200  /* Restart auto negotiation */
@@ -569,9 +575,11 @@
 
 /* PCI/PCI-X/PCI-EX Config space */
 #define PCIE_LINK_STATUS             0x12
+#define PCIE_DEVICE_CONTROL2         0x28
 
 #define PCIE_LINK_WIDTH_MASK         0x3F0
 #define PCIE_LINK_WIDTH_SHIFT        4
+#define PCIE_DEVICE_CONTROL2_16ms    0x0005
 
 #define PHY_REVISION_MASK      0xFFFFFFF0
 #define MAX_PHY_REG_ADDRESS    0x1F  /* 5 bit address bus (0-0x1F) */

drivers/net/igb/e1000_hw.h

@@ -494,5 +494,7 @@ extern char *igb_get_hw_dev_name(struct e1000_hw *hw);
 #else
 #define hw_dbg(format, arg...)
 #endif
-
 #endif
+/* These functions must be implemented by drivers */
+s32  igb_read_pcie_cap_reg(struct e1000_hw *hw, u32 reg, u16 *value);
+s32  igb_write_pcie_cap_reg(struct e1000_hw *hw, u32 reg, u16 *value);

drivers/net/igb/e1000_mac.c

@@ -37,20 +37,6 @@
 static s32 igb_set_default_fc(struct e1000_hw *hw);
 static s32 igb_set_fc_watermarks(struct e1000_hw *hw);
 
-static s32 igb_read_pcie_cap_reg(struct e1000_hw *hw, u32 reg, u16 *value)
-{
-	struct igb_adapter *adapter = hw->back;
-	u16 cap_offset;
-
-	cap_offset = pci_find_capability(adapter->pdev, PCI_CAP_ID_EXP);
-	if (!cap_offset)
-		return -E1000_ERR_CONFIG;
-
-	pci_read_config_word(adapter->pdev, cap_offset + reg, value);
-
-	return 0;
-}
-
 /**
  *  igb_get_bus_info_pcie - Get PCIe bus information
  *  @hw: pointer to the HW structure

drivers/net/igb/e1000_regs.h

@@ -305,6 +305,7 @@ enum {
 #define E1000_CCMCTL      0x05B48 /* CCM Control Register */
 #define E1000_GIOCTL      0x05B44 /* GIO Analog Control Register */
 #define E1000_SCCTL       0x05B4C /* PCIc PLL Configuration Register */
+#define E1000_GCR         0x05B00 /* PCI-Ex Control */
 #define E1000_FACTPS    0x05B30 /* Function Active and Power State to MNG */
 #define E1000_SWSM      0x05B50 /* SW Semaphore */
 #define E1000_FWSM      0x05B54 /* FW Semaphore */

drivers/net/igb/igb_main.c

@@ -5029,6 +5029,34 @@ static int igb_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
 	}
 }
 
+s32 igb_read_pcie_cap_reg(struct e1000_hw *hw, u32 reg, u16 *value)
+{
+	struct igb_adapter *adapter = hw->back;
+	u16 cap_offset;
+
+	cap_offset = pci_find_capability(adapter->pdev, PCI_CAP_ID_EXP);
+	if (!cap_offset)
+		return -E1000_ERR_CONFIG;
+
+	pci_read_config_word(adapter->pdev, cap_offset + reg, value);
+
+	return 0;
+}
+
+s32 igb_write_pcie_cap_reg(struct e1000_hw *hw, u32 reg, u16 *value)
+{
+	struct igb_adapter *adapter = hw->back;
+	u16 cap_offset;
+
+	cap_offset = pci_find_capability(adapter->pdev, PCI_CAP_ID_EXP);
+	if (!cap_offset)
+		return -E1000_ERR_CONFIG;
+
+	pci_write_config_word(adapter->pdev, cap_offset + reg, *value);
+
+	return 0;
+}
+
 static void igb_vlan_rx_register(struct net_device *netdev,
 				 struct vlan_group *grp)
 {