@@ -22,6 +22,10 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
+
+/* Root pointer to the mapped MCFG table */
+static struct acpi_table_mcfg *mcfg_table;
 
 /* Structure to hold entries from the MCFG table */
 struct mcfg_entry {

@@ -35,6 +39,46 @@ struct mcfg_entry {
 /* List to save MCFG entries */
 static LIST_HEAD(pci_mcfg_list);
 
+static bool pci_mcfg_fixup_match(struct pci_cfg_fixup *f,
+				 struct acpi_table_header *h)
+{
+	int olen = min_t(u8, strlen(f->oem_id), ACPI_OEM_ID_SIZE);
+	int tlen = min_t(u8, strlen(f->oem_table_id), ACPI_OEM_TABLE_ID_SIZE);
+
+	return (!strncmp(f->oem_id, h->oem_id, olen) &&
+		!strncmp(f->oem_table_id, h->oem_table_id, tlen) &&
+		f->oem_revision == h->oem_revision);
+}
+
+struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root)
+{
+	int bus_num = root->secondary.start;
+	int domain = root->segment;
+	struct pci_cfg_fixup *f;
+
+	if (!mcfg_table)
+		return &pci_generic_ecam_ops;
+
+	/*
+	 * Match against platform specific quirks and return corresponding CAM
+	 * ops.
+	 *
+	 * First match against PCI topology <domain:bus> then use OEM ID, OEM
+	 * table ID, and OEM revision from MCFG table standard header.
+	 */
+	for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups; f++) {
+		if ((f->domain == domain || f->domain == PCI_MCFG_DOMAIN_ANY) &&
+		    (f->bus_num == bus_num || f->bus_num == PCI_MCFG_BUS_ANY) &&
+		    pci_mcfg_fixup_match(f, &mcfg_table->header)) {
+			pr_info("Handling %s %s r%d PCI MCFG quirks\n",
+				f->oem_id, f->oem_table_id, f->oem_revision);
+			return f->ops;
+		}
+	}
+	/* No quirks, use ECAM */
+	return &pci_generic_ecam_ops;
+}
+
 phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res)
 {
 	struct mcfg_entry *e;

@@ -54,7 +98,6 @@ phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res)
 
 static __init int pci_mcfg_parse(struct acpi_table_header *header)
 {
-	struct acpi_table_mcfg *mcfg;
 	struct acpi_mcfg_allocation *mptr;
 	struct mcfg_entry *e, *arr;
 	int i, n;

@@ -64,8 +107,8 @@ static __init int pci_mcfg_parse(struct acpi_table_header *header)
 
 	n = (header->length - sizeof(struct acpi_table_mcfg)) /
 					sizeof(struct acpi_mcfg_allocation);
-	mcfg = (struct acpi_table_mcfg *)header;
-	mptr = (struct acpi_mcfg_allocation *) &mcfg[1];
+	mcfg_table = (struct acpi_table_mcfg *)header;
+	mptr = (struct acpi_mcfg_allocation *) &mcfg_table[1];
 
 	arr = kcalloc(n, sizeof(*arr), GFP_KERNEL);
 	if (!arr)

@@ -300,6 +300,13 @@
 		VMLINUX_SYMBOL(__end_pci_fixups_suspend_late) = .;	\
 	}								\
 									\
+	/* ACPI MCFG quirks */						\
+	.acpi_fixup        : AT(ADDR(.acpi_fixup) - LOAD_OFFSET) {	\
+		VMLINUX_SYMBOL(__start_acpi_mcfg_fixups) = .;		\
+		*(.acpi_fixup_mcfg)					\
+		VMLINUX_SYMBOL(__end_acpi_mcfg_fixups) = .;		\
+	}								\
+									\
 	/* Built-in firmware blobs */					\
 	.builtin_fw        : AT(ADDR(.builtin_fw) - LOAD_OFFSET) {	\
 		VMLINUX_SYMBOL(__start_builtin_fw) = .;			\

@@ -25,6 +25,7 @@ static inline acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 extern phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle);
 
 extern phys_addr_t pci_mcfg_lookup(u16 domain, struct resource *bus_res);
+extern struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root);
 
 static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
 {

@@ -72,6 +73,29 @@ struct acpi_pci_root_ops {
 	int (*prepare_resources)(struct acpi_pci_root_info *info);
 };
 
+struct pci_cfg_fixup {
+	struct pci_ecam_ops *ops;
+	char *oem_id;
+	char *oem_table_id;
+	u32 oem_revision;
+	int domain;
+	int bus_num;
+};
+
+extern struct pci_cfg_fixup __start_acpi_mcfg_fixups[];
+extern struct pci_cfg_fixup __end_acpi_mcfg_fixups[];
+
+#define PCI_MCFG_DOMAIN_ANY	-1
+#define PCI_MCFG_BUS_ANY	-1
+
+/* Designate a routine to fix up buggy MCFG */
+#define DECLARE_ACPI_MCFG_FIXUP(ops, oem, table, rev, dom, bus)	\
+	static const struct pci_cfg_fixup			\
+	__UNIQUE_ID(mcfg_fixup_)				\
+	__used	__attribute__((__section__(".acpi_fixup_mcfg"),	\
+				aligned((sizeof(void *))))) =	\
+	{ ops, oem, table, rev, dom, bus }
+
 extern int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info);
 extern struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 					    struct acpi_pci_root_ops *ops,