ixgbe: Fix race condition where RX buffer could become corrupted.

There was a race condition in the reset path where the RX buffer
could become corrupted during Fdir configuration.This is due to
a HW bug.The fix right now is to lock the buffer while we do the
fdir configuration.Since we were using similar workaround for another bug,
I moved the existing code to a function and reused it.HW team also recommended
that IXGBE_MAX_SECRX_POLL value be changed from 30 to 40.The erratum for this
bug will be published in the next release 82599 Spec Update

Signed-off-by: Atita Shirwaikar <atita.shirwaikar@intel.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_82599.c

@@ -1907,38 +1907,17 @@ out:
  **/
 static s32 ixgbe_enable_rx_dma_82599(struct ixgbe_hw *hw, u32 regval)
 {
-#define IXGBE_MAX_SECRX_POLL 30
-	int i;
-	int secrxreg;
-
 	/*
 	 * Workaround for 82599 silicon errata when enabling the Rx datapath.
 	 * If traffic is incoming before we enable the Rx unit, it could hang
 	 * the Rx DMA unit.  Therefore, make sure the security engine is
 	 * completely disabled prior to enabling the Rx unit.
 	 */
-	secrxreg = IXGBE_READ_REG(hw, IXGBE_SECRXCTRL);
+	hw->mac.ops.disable_rx_buff(hw);
-	secrxreg |= IXGBE_SECRXCTRL_RX_DIS;
-	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, secrxreg);
-	for (i = 0; i < IXGBE_MAX_SECRX_POLL; i++) {
-		secrxreg = IXGBE_READ_REG(hw, IXGBE_SECRXSTAT);
-		if (secrxreg & IXGBE_SECRXSTAT_SECRX_RDY)
-			break;
-		else
-			/* Use interrupt-safe sleep just in case */
-			udelay(10);
-	}
-
-	/* For informational purposes only */
-	if (i >= IXGBE_MAX_SECRX_POLL)
-		hw_dbg(hw, "Rx unit being enabled before security "
-		       "path fully disabled.  Continuing with init.\n");
 
 	IXGBE_WRITE_REG(hw, IXGBE_RXCTRL, regval);
-	secrxreg = IXGBE_READ_REG(hw, IXGBE_SECRXCTRL);
+
-	secrxreg &= ~IXGBE_SECRXCTRL_RX_DIS;
+	hw->mac.ops.enable_rx_buff(hw);
-	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, secrxreg);
-	IXGBE_WRITE_FLUSH(hw);
 
 	return 0;
 }
@@ -2103,6 +2082,8 @@ static struct ixgbe_mac_operations mac_ops_82599 = {
 	.get_media_type         = &ixgbe_get_media_type_82599,
 	.get_supported_physical_layer = &ixgbe_get_supported_physical_layer_82599,
 	.enable_rx_dma          = &ixgbe_enable_rx_dma_82599,
+	.disable_rx_buff	= &ixgbe_disable_rx_buff_generic,
+	.enable_rx_buff		= &ixgbe_enable_rx_buff_generic,
 	.get_mac_addr           = &ixgbe_get_mac_addr_generic,
 	.get_san_mac_addr       = &ixgbe_get_san_mac_addr_generic,
 	.get_device_caps        = &ixgbe_get_device_caps_generic,

drivers/net/ethernet/intel/ixgbe/ixgbe_common.c

@@ -2577,6 +2577,58 @@ void ixgbe_release_swfw_sync(struct ixgbe_hw *hw, u16 mask)
 	ixgbe_release_eeprom_semaphore(hw);
 }
 
+/**
+ *  ixgbe_disable_rx_buff_generic - Stops the receive data path
+ *  @hw: pointer to hardware structure
+ *
+ *  Stops the receive data path and waits for the HW to internally
+ *  empty the Rx security block.
+ **/
+s32 ixgbe_disable_rx_buff_generic(struct ixgbe_hw *hw)
+{
+#define IXGBE_MAX_SECRX_POLL 40
+	int i;
+	int secrxreg;
+
+	secrxreg = IXGBE_READ_REG(hw, IXGBE_SECRXCTRL);
+	secrxreg |= IXGBE_SECRXCTRL_RX_DIS;
+	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, secrxreg);
+	for (i = 0; i < IXGBE_MAX_SECRX_POLL; i++) {
+		secrxreg = IXGBE_READ_REG(hw, IXGBE_SECRXSTAT);
+		if (secrxreg & IXGBE_SECRXSTAT_SECRX_RDY)
+			break;
+		else
+			/* Use interrupt-safe sleep just in case */
+			udelay(10);
+	}
+
+	/* For informational purposes only */
+	if (i >= IXGBE_MAX_SECRX_POLL)
+		hw_dbg(hw, "Rx unit being enabled before security "
+		       "path fully disabled.  Continuing with init.\n");
+
+	return 0;
+
+}
+
+/**
+ *  ixgbe_enable_rx_buff - Enables the receive data path
+ *  @hw: pointer to hardware structure
+ *
+ *  Enables the receive data path
+ **/
+s32 ixgbe_enable_rx_buff_generic(struct ixgbe_hw *hw)
+{
+	int secrxreg;
+
+	secrxreg = IXGBE_READ_REG(hw, IXGBE_SECRXCTRL);
+	secrxreg &= ~IXGBE_SECRXCTRL_RX_DIS;
+	IXGBE_WRITE_REG(hw, IXGBE_SECRXCTRL, secrxreg);
+	IXGBE_WRITE_FLUSH(hw);
+
+	return 0;
+}
+
 /**
  *  ixgbe_enable_rx_dma_generic - Enable the Rx DMA unit
  *  @hw: pointer to hardware structure

drivers/net/ethernet/intel/ixgbe/ixgbe_common.h

@@ -74,6 +74,8 @@ s32 ixgbe_update_mc_addr_list_generic(struct ixgbe_hw *hw,
 				      struct net_device *netdev);
 s32 ixgbe_enable_mc_generic(struct ixgbe_hw *hw);
 s32 ixgbe_disable_mc_generic(struct ixgbe_hw *hw);
+s32 ixgbe_disable_rx_buff_generic(struct ixgbe_hw *hw);
+s32 ixgbe_enable_rx_buff_generic(struct ixgbe_hw *hw);
 s32 ixgbe_enable_rx_dma_generic(struct ixgbe_hw *hw, u32 regval);
 s32 ixgbe_fc_enable_generic(struct ixgbe_hw *hw, s32 packetbuf_num);
 s32 ixgbe_fc_autoneg(struct ixgbe_hw *hw);

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -3661,6 +3661,8 @@ static void ixgbe_fdir_filter_restore(struct ixgbe_adapter *adapter)
 
 static void ixgbe_configure(struct ixgbe_adapter *adapter)
 {
+	struct ixgbe_hw *hw = &adapter->hw;
+
 	ixgbe_configure_pb(adapter);
 #ifdef CONFIG_IXGBE_DCB
 	ixgbe_configure_dcb(adapter);
@@ -3674,6 +3676,16 @@ static void ixgbe_configure(struct ixgbe_adapter *adapter)
 		ixgbe_configure_fcoe(adapter);
 
 #endif /* IXGBE_FCOE */
+
+	switch (hw->mac.type) {
+	case ixgbe_mac_82599EB:
+	case ixgbe_mac_X540:
+		hw->mac.ops.disable_rx_buff(hw);
+		break;
+	default:
+		break;
+	}
+
 	if (adapter->flags & IXGBE_FLAG_FDIR_HASH_CAPABLE) {
 		ixgbe_init_fdir_signature_82599(&adapter->hw,
 						adapter->fdir_pballoc);
@@ -3683,6 +3695,15 @@ static void ixgbe_configure(struct ixgbe_adapter *adapter)
 		ixgbe_fdir_filter_restore(adapter);
 	}
 
+	switch (hw->mac.type) {
+	case ixgbe_mac_82599EB:
+	case ixgbe_mac_X540:
+		hw->mac.ops.enable_rx_buff(hw);
+		break;
+	default:
+		break;
+	}
+
 	ixgbe_configure_virtualization(adapter);
 
 	ixgbe_configure_tx(adapter);

drivers/net/ethernet/intel/ixgbe/ixgbe_type.h

@@ -2728,6 +2728,8 @@ struct ixgbe_mac_operations {
 	s32 (*read_analog_reg8)(struct ixgbe_hw*, u32, u8*);
 	s32 (*write_analog_reg8)(struct ixgbe_hw*, u32, u8);
 	s32 (*setup_sfp)(struct ixgbe_hw *);
+	s32 (*disable_rx_buff)(struct ixgbe_hw *);
+	s32 (*enable_rx_buff)(struct ixgbe_hw *);
 	s32 (*enable_rx_dma)(struct ixgbe_hw *, u32);
 	s32 (*acquire_swfw_sync)(struct ixgbe_hw *, u16);
 	void (*release_swfw_sync)(struct ixgbe_hw *, u16);

drivers/net/ethernet/intel/ixgbe/ixgbe_x540.c

@@ -847,6 +847,8 @@ static struct ixgbe_mac_operations mac_ops_X540 = {
 	.set_vlan_anti_spoofing = &ixgbe_set_vlan_anti_spoofing,
 	.acquire_swfw_sync      = &ixgbe_acquire_swfw_sync_X540,
 	.release_swfw_sync      = &ixgbe_release_swfw_sync_X540,
+	.disable_rx_buff	= &ixgbe_disable_rx_buff_generic,
+	.enable_rx_buff		= &ixgbe_enable_rx_buff_generic,
 };
 
 static struct ixgbe_eeprom_operations eeprom_ops_X540 = {