PCI: EPF: tvnet: disable the edma interrupt

1. Disable the corresponding PCIe EP controller
   EDMA interrupt.
2. Disable IP checksum to improve performance
   since the PCIe link is reliable.
3. DMA unmap matches the map size.
4. Adjust the SKB buffer link list handle.

Bug 4704944

Signed-off-by: Jason Mei <jianjunm@nvidia.com>
Change-Id: I05f76fa60e3533c2dd01e53ed17664d6898fcffd
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3158126
Reviewed-by: svcacv <svcacv@nvidia.com>
Reviewed-by: Nagarjuna Kristam <nkristam@nvidia.com>
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>

drivers/net/ethernet/nvidia/pcie/tegra_vnet.c

@@ -183,6 +183,11 @@ static void tvnet_host_alloc_empty_buffers(struct tvnet_priv *tvnet)
 			break;
 		}
 
+		/* The PCIe link is stable and dependable,
+		 * so it's not necessary to perform a software checksum.
+		 */
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
 		ep2h_empty_ptr = kmalloc(sizeof(*ep2h_empty_ptr), GFP_ATOMIC);
 		if (!ep2h_empty_ptr) {
 			dma_unmap_single(d, iova, len, DMA_FROM_DEVICE);
@@ -651,16 +656,18 @@ static int tvnet_host_process_ep2h_msg(struct tvnet_priv *tvnet)
 		list_for_each_entry(ep2h_empty_ptr, &tvnet->ep2h_empty_list,
 				    list) {
 			if (ep2h_empty_ptr->iova == pcie_address) {
+				list_del(&ep2h_empty_ptr->list);
 				found = 1;
 				break;
 			}
 		}
-		WARN_ON(!found);
-		list_del(&ep2h_empty_ptr->list);
 		spin_unlock_irqrestore(&tvnet->ep2h_empty_lock, flags);
 
 		/* Advance H2EP full buffer after search in local list */
 		tvnet_ivc_advance_rd(&tvnet->ep2h_full);
+		if (WARN_ON(!found))
+			continue;
+
 		/* If EP2H network queue is stopped due to lack of EP2H_FULL
 		 * queue, raising ctrl irq will help.
 		 */

drivers/pci/endpoint/functions/pci-epf-tegra-vnet.c

@@ -30,6 +30,8 @@
 #endif
 
 #define BAR0_SIZE SZ_4M
+#define APPL_INTR_EN_L1_8_0                     0x44
+#define APPL_INTR_EN_L1_8_EDMA_INT_EN           BIT(6)
 
 enum bar0_amap_type {
 	META_DATA,
@@ -146,6 +148,8 @@ struct pci_epf_tvnet {
 	/* IOVA alloc abstraction.*/
 	struct iova_domain *iovad;
 	struct iova *iova;
+	struct resource *appl_res;
+	void __iomem *appl_base;
 #endif
 };
 
@@ -304,6 +308,10 @@ static void tvnet_ep_alloc_empty_buffers(struct pci_epf_tvnet *tvnet)
 			break;
 		}
 
+		/* The PCIe link is stable and dependable,
+		 * so it's not necessary to perform a software checksum.
+		 */
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
 #else
 		iova = tvnet_ivoa_alloc(tvnet);
 		if (iova == DMA_ERROR_CODE) {
@@ -849,18 +857,19 @@ static int tvnet_ep_process_h2ep_msg(struct pci_epf_tvnet *tvnet)
 		list_for_each_entry(h2ep_empty_ptr, &tvnet->h2ep_empty_list,
 				    list) {
 			if (h2ep_empty_ptr->iova == pcie_address) {
+				list_del(&h2ep_empty_ptr->list);
 				found = 1;
 				break;
 			}
 		}
-		WARN_ON(!found);
-		list_del(&h2ep_empty_ptr->list);
 		spin_unlock_irqrestore(&tvnet->h2ep_empty_lock, flags);
 
 		/* Advance H2EP full buffer after search in local list */
 		tvnet_ivc_advance_rd(&tvnet->h2ep_full);
+		if (WARN_ON(!found))
+			continue;
 #if ENABLE_DMA
-		dma_unmap_single(cdev, pcie_address, ndev->mtu,
+		dma_unmap_single(cdev, pcie_address, ndev->mtu + ETH_HLEN,
 				 DMA_FROM_DEVICE);
 		skb = h2ep_empty_ptr->skb;
 		skb_put(skb, len);
@@ -1597,7 +1606,7 @@ static void tvnet_ep_pci_epf_linkup(struct pci_epf *epf)
 #endif
 {
 	struct pci_epf_tvnet *tvnet = epf_get_drvdata(epf);
-
+	u32 val;
 #if ENABLE_DMA
 	tvnet_ep_setup_dma(tvnet);
 #endif
@@ -1611,6 +1620,11 @@ static void tvnet_ep_pci_epf_linkup(struct pci_epf *epf)
 
 	tvnet->pcie_link_status = true;
 #if (LINUX_VERSION_CODE > KERNEL_VERSION(5, 14, 0))
+	val = readl(tvnet->appl_base + APPL_INTR_EN_L1_8_0);
+	if (val & APPL_INTR_EN_L1_8_EDMA_INT_EN)
+		writel(val & ~APPL_INTR_EN_L1_8_EDMA_INT_EN,
+			tvnet->appl_base + APPL_INTR_EN_L1_8_0);
+
 	return 0;
 #endif
 }
@@ -1714,6 +1728,18 @@ static int tvnet_ep_pci_epf_bind(struct pci_epf *epf)
 		goto fail;
 	}
 
+	tvnet->appl_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+							"appl");
+	if (!tvnet->appl_res) {
+		dev_err(fdev, "Failed to find \"appl\" region\n");
+		goto fail;
+	}
+
+	tvnet->appl_base = devm_ioremap(fdev, tvnet->appl_res->start,
+					PAGE_SIZE);
+	if (IS_ERR(tvnet->appl_base))
+		goto fail;
+
 #if (LINUX_VERSION_CODE > KERNEL_VERSION(5, 14, 0))
 	tvnet->iovad = (struct iova_domain *)&domain->iova_cookie->iovad;