diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index a54b48f7cee2b272c7c670cf70aca148ea98f5d6..7a6d34ee5ab132593c2efce4000edd3bb3af3408 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -494,6 +494,13 @@
 #define HT_CAPTYPE_UNITID_CLUMP	0x90	/* Unit ID clumping */
 #define HT_CAPTYPE_EXTCONF	0x98	/* Extended Configuration Space Access */
 #define HT_CAPTYPE_MSI_MAPPING	0xA8	/* MSI Mapping Capability */
+#define  HT_MSI_FLAGS		0x02		/* Offset to flags */
+#define  HT_MSI_FLAGS_ENABLE	0x1		/* Mapping enable */
+#define  HT_MSI_FLAGS_FIXED	0x2		/* Fixed mapping only */
+#define  HT_MSI_FIXED_ADDR	0x00000000FEE00000ULL	/* Fixed addr */
+#define  HT_MSI_ADDR_LO		0x04		/* Offset to low addr bits */
+#define  HT_MSI_ADDR_LO_MASK	0xFFF00000	/* Low address bit mask */
+#define  HT_MSI_ADDR_HI		0x08		/* Offset to high addr bits */
 #define HT_CAPTYPE_DIRECT_ROUTE	0xB0	/* Direct routing configuration */
 #define HT_CAPTYPE_VCSET	0xB8	/* Virtual Channel configuration */
 #define HT_CAPTYPE_ERROR_RETRY	0xC0	/* Retry on error configuration */