diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 758cbfe55daa..4b3efaa82ab7 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/efi.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/bitmap.h>
@@ -442,17 +443,42 @@ static bool is_acpi_reserved(u64 start, u64 end, enum e820_type not_used)
 	return mcfg_res.flags;
 }
 
+static bool is_efi_mmio(u64 start, u64 end, enum e820_type not_used)
+{
+#ifdef CONFIG_EFI
+	efi_memory_desc_t *md;
+	u64 size, mmio_start, mmio_end;
+
+	for_each_efi_memory_desc(md) {
+		if (md->type == EFI_MEMORY_MAPPED_IO) {
+			size = md->num_pages << EFI_PAGE_SHIFT;
+			mmio_start = md->phys_addr;
+			mmio_end = mmio_start + size;
+
+			/*
+			 * N.B. Caller supplies (start, start + size),
+			 * so to match, mmio_end is the first address
+			 * *past* the EFI_MEMORY_MAPPED_IO area.
+			 */
+			if (mmio_start <= start && end <= mmio_end)
+				return true;
+		}
+	}
+#endif
+
+	return false;
+}
+
 typedef bool (*check_reserved_t)(u64 start, u64 end, enum e820_type type);
 
 static bool __ref is_mmconf_reserved(check_reserved_t is_reserved,
 				     struct pci_mmcfg_region *cfg,
-				     struct device *dev, int with_e820)
+				     struct device *dev, const char *method)
 {
 	u64 addr = cfg->res.start;
 	u64 size = resource_size(&cfg->res);
 	u64 old_size = size;
 	int num_buses;
-	char *method = with_e820 ? "E820" : "ACPI motherboard resources";
 
 	while (!is_reserved(addr, addr + size, E820_TYPE_RESERVED)) {
 		size >>= 1;
@@ -464,10 +490,10 @@ static bool __ref is_mmconf_reserved(check_reserved_t is_reserved,
 		return false;
 
 	if (dev)
-		dev_info(dev, "MMCONFIG at %pR reserved in %s\n",
+		dev_info(dev, "MMCONFIG at %pR reserved as %s\n",
 			 &cfg->res, method);
 	else
-		pr_info(PREFIX "MMCONFIG at %pR reserved in %s\n",
+		pr_info(PREFIX "MMCONFIG at %pR reserved as %s\n",
 		       &cfg->res, method);
 
 	if (old_size != size) {
@@ -500,7 +526,8 @@ static bool __ref
 pci_mmcfg_check_reserved(struct device *dev, struct pci_mmcfg_region *cfg, int early)
 {
 	if (!early && !acpi_disabled) {
-		if (is_mmconf_reserved(is_acpi_reserved, cfg, dev, 0))
+		if (is_mmconf_reserved(is_acpi_reserved, cfg, dev,
+				       "ACPI motherboard resource"))
 			return true;
 
 		if (dev)
@@ -513,6 +540,10 @@ pci_mmcfg_check_reserved(struct device *dev, struct pci_mmcfg_region *cfg, int e
 			       "MMCONFIG at %pR not reserved in "
 			       "ACPI motherboard resources\n",
 			       &cfg->res);
+
+		if (is_mmconf_reserved(is_efi_mmio, cfg, dev,
+				       "EfiMemoryMappedIO"))
+			return true;
 	}
 
 	/*
@@ -527,7 +558,8 @@ pci_mmcfg_check_reserved(struct device *dev, struct pci_mmcfg_region *cfg, int e
 	/* Don't try to do this check unless configuration
 	   type 1 is available. how about type 2 ?*/
 	if (raw_pci_ops)
-		return is_mmconf_reserved(e820__mapped_all, cfg, dev, 1);
+		return is_mmconf_reserved(e820__mapped_all, cfg, dev,
+					  "E820 entry");
 
 	return false;
 }
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index a0d2713f0e88..99ec91e2a5cf 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -225,7 +225,7 @@ config PCIE_ARTPEC6_EP
 config PCIE_BT1
 	tristate "Baikal-T1 PCIe controller"
 	depends on MIPS_BAIKAL_T1 || COMPILE_TEST
-	depends on PCI_MSI_IRQ_DOMAIN
+	depends on PCI_MSI
 	select PCIE_DW_HOST
 	help
 	  Enables support for the PCIe controller in the Baikal-T1 SoC to work