diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 553ca6657955..4db261e13e69 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1299,6 +1299,38 @@ void pci_pm_init(struct pci_dev *dev)
 	}
 }
 
+/**
+ * pci_enable_ari - enable ARI forwarding if hardware support it
+ * @dev: the PCI device
+ */
+void pci_enable_ari(struct pci_dev *dev)
+{
+	int pos;
+	u32 cap;
+	u16 ctrl;
+
+	if (!dev->is_pcie)
+		return;
+
+	if (dev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
+	    dev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
+		return;
+
+	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
+	if (!pos)
+		return;
+
+	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
+	if (!(cap & PCI_EXP_DEVCAP2_ARI))
+		return;
+
+	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
+	ctrl |= PCI_EXP_DEVCTL2_ARI;
+	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
+
+	dev->ari_enabled = 1;
+}
+
 int
 pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
 {
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 601abdc8dd9f..39684c1415c5 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -151,4 +151,16 @@ struct pci_slot_attribute {
 };
 #define to_pci_slot_attr(s) container_of(s, struct pci_slot_attribute, attr)
 
+extern void pci_enable_ari(struct pci_dev *dev);
+/**
+ * pci_ari_enabled - query ARI forwarding status
+ * @dev: the PCI device
+ *
+ * Returns 1 if ARI forwarding is enabled, or 0 if not enabled;
+ */
+static inline int pci_ari_enabled(struct pci_dev *dev)
+{
+	return dev->ari_enabled;
+}
+
 #endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8c158b9abd41..3141e8deeac4 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1025,6 +1025,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
 
 	/* Vital Product Data */
 	pci_vpd_pci22_init(dev);
+
+	/* Alternative Routing-ID Forwarding */
+	pci_enable_ari(dev);
 }
 
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 008005674b60..7e9a1f0715e6 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -214,6 +214,7 @@ struct pci_dev {
 	unsigned int	broken_parity_status:1;	/* Device generates false positive parity */
 	unsigned int 	msi_enabled:1;
 	unsigned int	msix_enabled:1;
+	unsigned int	ari_enabled:1;	/* ARI forwarding */
 	unsigned int	is_managed:1;
 	unsigned int	is_pcie:1;
 	pci_dev_flags_t dev_flags;
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index 450684f7eaac..eb6686b88f9a 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -419,6 +419,10 @@
 #define  PCI_EXP_RTCTL_CRSSVE	0x10	/* CRS Software Visibility Enable */
 #define PCI_EXP_RTCAP		30	/* Root Capabilities */
 #define PCI_EXP_RTSTA		32	/* Root Status */
+#define PCI_EXP_DEVCAP2		36	/* Device Capabilities 2 */
+#define  PCI_EXP_DEVCAP2_ARI	0x20	/* Alternative Routing-ID */
+#define PCI_EXP_DEVCTL2		40	/* Device Control 2 */
+#define  PCI_EXP_DEVCTL2_ARI	0x20	/* Alternative Routing-ID */
 
 /* Extended Capabilities (PCI-X 2.0 and Express) */
 #define PCI_EXT_CAP_ID(header)		(header & 0x0000ffff)
@@ -429,6 +433,7 @@
 #define PCI_EXT_CAP_ID_VC	2
 #define PCI_EXT_CAP_ID_DSN	3
 #define PCI_EXT_CAP_ID_PWR	4
+#define PCI_EXT_CAP_ID_ARI	14
 
 /* Advanced Error Reporting */
 #define PCI_ERR_UNCOR_STATUS	4	/* Uncorrectable Error Status */
@@ -536,5 +541,14 @@
 #define HT_CAPTYPE_GEN3		0xD0	/* Generation 3 hypertransport configuration */
 #define HT_CAPTYPE_PM		0xE0	/* Hypertransport powermanagement configuration */
 
+/* Alternative Routing-ID Interpretation */
+#define PCI_ARI_CAP		0x04	/* ARI Capability Register */
+#define  PCI_ARI_CAP_MFVC	0x0001	/* MFVC Function Groups Capability */
+#define  PCI_ARI_CAP_ACS	0x0002	/* ACS Function Groups Capability */
+#define  PCI_ARI_CAP_NFN(x)	(((x) >> 8) & 0xff) /* Next Function Number */
+#define PCI_ARI_CTRL		0x06	/* ARI Control Register */
+#define  PCI_ARI_CTRL_MFVC	0x0001	/* MFVC Function Groups Enable */
+#define  PCI_ARI_CTRL_ACS	0x0002	/* ACS Function Groups Enable */
+#define  PCI_ARI_CTRL_FG(x)	(((x) >> 4) & 7) /* Function Group */
 
 #endif /* LINUX_PCI_REGS_H */