PCI: mvebu: Add support for Advanced Error Reporting registers on emulated bridge

AER registers start at mvebu offset 0x0100. Registers PCI_ERR_ROOT_COMMAND,
PCI_ERR_ROOT_STATUS and PCI_ERR_ROOT_ERR_SRC are not supported on pre-XP
hardware and returns zeros.

Note that AER interrupt is not supported yet as mvebu emulated bridge does
not implement interrupts support at all yet.

Also remove custom macro PCIE_HEADER_LOG_4_OFF as it is unused and
correctly this register should be referenced via standard macros with
offset, e.g. as: PCIE_CAP_PCIERR_OFF + PCI_ERR_HEADER_LOG + 4.

Link: https://lore.kernel.org/r/20220222155030.988-8-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Author: pali

drivers/pci/controller/pci-mvebu.c

@@ -34,7 +34,7 @@
 #define PCIE_BAR_HI_OFF(n)	(0x0014 + ((n) << 3))
 #define PCIE_SSDEV_ID_OFF	0x002c
 #define PCIE_CAP_PCIEXP		0x0060
-#define PCIE_HEADER_LOG_4_OFF	0x0128
+#define PCIE_CAP_PCIERR_OFF	0x0100
 #define PCIE_BAR_CTRL_OFF(n)	(0x1804 + (((n) - 1) * 4))
 #define PCIE_WIN04_CTRL_OFF(n)	(0x1820 + ((n) << 4))
 #define PCIE_WIN04_BASE_OFF(n)	(0x1824 + ((n) << 4))
@@ -603,6 +603,37 @@ mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
 	return PCI_BRIDGE_EMUL_HANDLED;
 }
 
+static pci_bridge_emul_read_status_t
+mvebu_pci_bridge_emul_ext_conf_read(struct pci_bridge_emul *bridge,
+				    int reg, u32 *value)
+{
+	struct mvebu_pcie_port *port = bridge->data;
+
+	switch (reg) {
+	case 0:
+	case PCI_ERR_UNCOR_STATUS:
+	case PCI_ERR_UNCOR_MASK:
+	case PCI_ERR_UNCOR_SEVER:
+	case PCI_ERR_COR_STATUS:
+	case PCI_ERR_COR_MASK:
+	case PCI_ERR_CAP:
+	case PCI_ERR_HEADER_LOG+0:
+	case PCI_ERR_HEADER_LOG+4:
+	case PCI_ERR_HEADER_LOG+8:
+	case PCI_ERR_HEADER_LOG+12:
+	case PCI_ERR_ROOT_COMMAND:
+	case PCI_ERR_ROOT_STATUS:
+	case PCI_ERR_ROOT_ERR_SRC:
+		*value = mvebu_readl(port, PCIE_CAP_PCIERR_OFF + reg);
+		break;
+
+	default:
+		return PCI_BRIDGE_EMUL_NOT_HANDLED;
+	}
+
+	return PCI_BRIDGE_EMUL_HANDLED;
+}
+
 static void
 mvebu_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
 				      int reg, u32 old, u32 new, u32 mask)
@@ -715,11 +746,45 @@ mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
 	}
 }
 
+static void
+mvebu_pci_bridge_emul_ext_conf_write(struct pci_bridge_emul *bridge,
+				     int reg, u32 old, u32 new, u32 mask)
+{
+	struct mvebu_pcie_port *port = bridge->data;
+
+	switch (reg) {
+	/* These are W1C registers, so clear other bits */
+	case PCI_ERR_UNCOR_STATUS:
+	case PCI_ERR_COR_STATUS:
+	case PCI_ERR_ROOT_STATUS:
+		new &= mask;
+		fallthrough;
+
+	case PCI_ERR_UNCOR_MASK:
+	case PCI_ERR_UNCOR_SEVER:
+	case PCI_ERR_COR_MASK:
+	case PCI_ERR_CAP:
+	case PCI_ERR_HEADER_LOG+0:
+	case PCI_ERR_HEADER_LOG+4:
+	case PCI_ERR_HEADER_LOG+8:
+	case PCI_ERR_HEADER_LOG+12:
+	case PCI_ERR_ROOT_COMMAND:
+	case PCI_ERR_ROOT_ERR_SRC:
+		mvebu_writel(port, new, PCIE_CAP_PCIERR_OFF + reg);
+		break;
+
+	default:
+		break;
+	}
+}
+
 static const struct pci_bridge_emul_ops mvebu_pci_bridge_emul_ops = {
 	.read_base = mvebu_pci_bridge_emul_base_conf_read,
 	.write_base = mvebu_pci_bridge_emul_base_conf_write,
 	.read_pcie = mvebu_pci_bridge_emul_pcie_conf_read,
 	.write_pcie = mvebu_pci_bridge_emul_pcie_conf_write,
+	.read_ext = mvebu_pci_bridge_emul_ext_conf_read,
+	.write_ext = mvebu_pci_bridge_emul_ext_conf_write,
 };
 
 /*