ixgbe: Check register reads for adapter removal

Check all register reads for adapter removal by checking the status
register after any register read that returns 0xFFFFFFFF. Since the
status register will never return 0xFFFFFFFF unless the adapter is
removed, such a value from a status register read confirms the
removal.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 34 insertions, 4 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 01df3763224d..9831a244d5ba 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -283,6 +283,35 @@ static void ixgbe_service_event_schedule(struct ixgbe_adapter *adapter)
 		schedule_work(&adapter->service_task);
 }
 
+static void ixgbe_remove_adapter(struct ixgbe_hw *hw)
+{
+	struct ixgbe_adapter *adapter = hw->back;
+
+	if (!hw->hw_addr)
+		return;
+	hw->hw_addr = NULL;
+	e_dev_err("Adapter removed\n");
+}
+
+void ixgbe_check_remove(struct ixgbe_hw *hw, u32 reg)
+{
+	u32 value;
+
+	/* The following check not only optimizes a bit by not
+	 * performing a read on the status register when the
+	 * register just read was a status register read that
+	 * returned IXGBE_FAILED_READ_REG. It also blocks any
+	 * potential recursion.
+	 */
+	if (reg == IXGBE_STATUS) {
+		ixgbe_remove_adapter(hw);
+		return;
+	}
+	value = ixgbe_read_reg(hw, IXGBE_STATUS);
+	if (value == IXGBE_FAILED_READ_REG)
+		ixgbe_remove_adapter(hw);
+}
+
 static void ixgbe_service_event_complete(struct ixgbe_adapter *adapter)
 {
 	BUG_ON(!test_bit(__IXGBE_SERVICE_SCHED, &adapter->state));
@@ -2970,7 +2999,7 @@ void ixgbe_configure_tx_ring(struct ixgbe_adapter *adapter,
 			ring->count * sizeof(union ixgbe_adv_tx_desc));
 	IXGBE_WRITE_REG(hw, IXGBE_TDH(reg_idx), 0);
 	IXGBE_WRITE_REG(hw, IXGBE_TDT(reg_idx), 0);
-	ring->tail = hw->hw_addr + IXGBE_TDT(reg_idx);
+	ring->tail = adapter->io_addr + IXGBE_TDT(reg_idx);
 
 	/*
 	 * set WTHRESH to encourage burst writeback, it should not be set
@@ -3373,7 +3402,7 @@ void ixgbe_configure_rx_ring(struct ixgbe_adapter *adapter,
 			ring->count * sizeof(union ixgbe_adv_rx_desc));
 	IXGBE_WRITE_REG(hw, IXGBE_RDH(reg_idx), 0);
 	IXGBE_WRITE_REG(hw, IXGBE_RDT(reg_idx), 0);
-	ring->tail = hw->hw_addr + IXGBE_RDT(reg_idx);
+	ring->tail = adapter->io_addr + IXGBE_RDT(reg_idx);
 
 	ixgbe_configure_srrctl(adapter, ring);
 	ixgbe_configure_rscctl(adapter, ring);
@@ -7880,6 +7909,7 @@ static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	hw->hw_addr = ioremap(pci_resource_start(pdev, 0),
 			      pci_resource_len(pdev, 0));
+	adapter->io_addr = hw->hw_addr;
 	if (!hw->hw_addr) {
 		err = -EIO;
 		goto err_ioremap;
@@ -8188,7 +8218,7 @@ err_register:
 err_sw_init:
 	ixgbe_disable_sriov(adapter);
 	adapter->flags2 &= ~IXGBE_FLAG2_SEARCH_FOR_SFP;
-	iounmap(hw->hw_addr);
+	iounmap(adapter->io_addr);
 err_ioremap:
 	free_netdev(netdev);
 err_alloc_etherdev:
@@ -8255,7 +8285,7 @@ static void ixgbe_remove(struct pci_dev *pdev)
 	kfree(adapter->ixgbe_ieee_ets);
 
 #endif
-	iounmap(adapter->hw.hw_addr);
+	iounmap(adapter->io_addr);
 	pci_release_selected_regions(pdev, pci_select_bars(pdev,
 				     IORESOURCE_MEM));