Merge branch 'sfc-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/bwh/sfc-2.6

drivers/net/sfc/efx.c

@@ -1054,6 +1054,7 @@ static int efx_init_io(struct efx_nic *efx)
 {
 	struct pci_dev *pci_dev = efx->pci_dev;
 	dma_addr_t dma_mask = efx->type->max_dma_mask;
+	bool use_wc;
 	int rc;
 
 	netif_dbg(efx, probe, efx->net_dev, "initialising I/O\n");
@@ -1104,8 +1105,21 @@ static int efx_init_io(struct efx_nic *efx)
 		rc = -EIO;
 		goto fail3;
 	}
-	efx->membase = ioremap_wc(efx->membase_phys,
-				  efx->type->mem_map_size);
+
+	/* bug22643: If SR-IOV is enabled then tx push over a write combined
+	 * mapping is unsafe. We need to disable write combining in this case.
+	 * MSI is unsupported when SR-IOV is enabled, and the firmware will
+	 * have removed the MSI capability. So write combining is safe if
+	 * there is an MSI capability.
+	 */
+	use_wc = (!EFX_WORKAROUND_22643(efx) ||
+		  pci_find_capability(pci_dev, PCI_CAP_ID_MSI));
+	if (use_wc)
+		efx->membase = ioremap_wc(efx->membase_phys,
+					  efx->type->mem_map_size);
+	else
+		efx->membase = ioremap_nocache(efx->membase_phys,
+					       efx->type->mem_map_size);
 	if (!efx->membase) {
 		netif_err(efx, probe, efx->net_dev,
 			  "could not map memory BAR at %llx+%x\n",

drivers/net/sfc/workarounds.h

@@ -38,6 +38,8 @@
 #define EFX_WORKAROUND_15783 EFX_WORKAROUND_ALWAYS
 /* Legacy interrupt storm when interrupt fifo fills */
 #define EFX_WORKAROUND_17213 EFX_WORKAROUND_SIENA
+/* Write combining and sriov=enabled are incompatible */
+#define EFX_WORKAROUND_22643 EFX_WORKAROUND_SIENA
 
 /* Spurious parity errors in TSORT buffers */
 #define EFX_WORKAROUND_5129 EFX_WORKAROUND_FALCON_A