be2net: use PCI MMIO read instead of config read for errors

When an EEH error occurs, the device/slot is disconnected. This condition
is more reliably detected (i.e., returns all ones) with an MMIO read rather
than a config read -- especially on power platforms.

Hence, this patch fixes EEH error detection by replacing config reads with
MMIO reads for reading the error registers. The error registers in
Skyhawk-R/BE2/BE3 are accessible both via the config space and the
PCICFG (BAR0) memory space.

Reported-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Suresh Reddy <Suresh.Reddy@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 23 insertions, 11 deletions

diff --git a/drivers/net/ethernet/emulex/benet/be.h b/drivers/net/ethernet/emulex/benet/be.h
index 92eb0c82bb04..27b9fe99a9bd 100644
--- a/drivers/net/ethernet/emulex/benet/be.h
+++ b/drivers/net/ethernet/emulex/benet/be.h
@@ -424,6 +424,7 @@ struct be_adapter {
 
         u8 __iomem *csr;        /* CSR BAR used only for BE2/3 */
         u8 __iomem *db;         /* Door Bell */
+        u8 __iomem *pcicfg;     /* On SH,BEx only. Shadow of PCI config space */
 
         struct mutex mbox_lock; /* For serializing mbox cmds to BE card */
         struct be_dma_mem mbox_mem;
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index eb2bed92bf60..e6b790f0d9dc 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -2823,14 +2823,12 @@ void be_detect_error(struct be_adapter *adapter)
                         }
                 }
         } else {
-                pci_read_config_dword(adapter->pdev,
-                                      PCICFG_UE_STATUS_LOW, &ue_lo);
-                pci_read_config_dword(adapter->pdev,
-                                      PCICFG_UE_STATUS_HIGH, &ue_hi);
-                pci_read_config_dword(adapter->pdev,
-                                      PCICFG_UE_STATUS_LOW_MASK, &ue_lo_mask);
-                pci_read_config_dword(adapter->pdev,
-                                      PCICFG_UE_STATUS_HI_MASK, &ue_hi_mask);
+                ue_lo = ioread32(adapter->pcicfg + PCICFG_UE_STATUS_LOW);
+                ue_hi = ioread32(adapter->pcicfg + PCICFG_UE_STATUS_HIGH);
+                ue_lo_mask = ioread32(adapter->pcicfg +
+                                      PCICFG_UE_STATUS_LOW_MASK);
+                ue_hi_mask = ioread32(adapter->pcicfg +
+                                      PCICFG_UE_STATUS_HI_MASK);
 
                 ue_lo = (ue_lo & ~ue_lo_mask);
                 ue_hi = (ue_hi & ~ue_hi_mask);
@@ -4874,24 +4872,37 @@ static int be_roce_map_pci_bars(struct be_adapter *adapter)
 
 static int be_map_pci_bars(struct be_adapter *adapter)
 {
+        struct pci_dev *pdev = adapter->pdev;
         u8 __iomem *addr;
 
         if (BEx_chip(adapter) && be_physfn(adapter)) {
-                adapter->csr = pci_iomap(adapter->pdev, 2, 0);
+                adapter->csr = pci_iomap(pdev, 2, 0);
                 if (!adapter->csr)
                         return -ENOMEM;
         }
 
-        addr = pci_iomap(adapter->pdev, db_bar(adapter), 0);
+        addr = pci_iomap(pdev, db_bar(adapter), 0);
         if (!addr)
                 goto pci_map_err;
         adapter->db = addr;
 
+        if (skyhawk_chip(adapter) || BEx_chip(adapter)) {
+                if (be_physfn(adapter)) {
+                        /* PCICFG is the 2nd BAR in BE2 */
+                        addr = pci_iomap(pdev, BE2_chip(adapter) ? 1 : 0, 0);
+                        if (!addr)
+                                goto pci_map_err;
+                        adapter->pcicfg = addr;
+                } else {
+                        adapter->pcicfg = adapter->db + SRIOV_VF_PCICFG_OFFSET;
+                }
+        }
+
         be_roce_map_pci_bars(adapter);
         return 0;
 
 pci_map_err:
-        dev_err(&adapter->pdev->dev, "Error in mapping PCI BARs\n");
+        dev_err(&pdev->dev, "Error in mapping PCI BARs\n");
         be_unmap_pci_bars(adapter);
         return -ENOMEM;
 }