diff --git a/src/northbridge/intel/sandybridge/acpi.c b/src/northbridge/intel/sandybridge/acpi.c
index 755d446..2c98674 100644
--- a/src/northbridge/intel/sandybridge/acpi.c
+++ b/src/northbridge/intel/sandybridge/acpi.c
@@ -11,48 +11,19 @@
 
 unsigned long acpi_fill_mcfg(unsigned long current)
 {
-	u32 pciexbar = 0;
-	u32 pciexbar_reg;
-	int max_buses;
+	u32 length, pciexbar;
 
-	struct device *const dev = pcidev_on_root(0, 0);
-
-	if (!dev)
+	if (!decode_pcie_bar(&pciexbar, &length))
 		return current;
 
-	pciexbar_reg = pci_read_config32(dev, PCIEXBAR);
-
-	/* MMCFG not supported or not enabled */
-	if (!(pciexbar_reg & (1 << 0)))
-		return current;
-
-	switch ((pciexbar_reg >> 1) & 3) {
-	case 0: /* 256MB */
-		pciexbar = pciexbar_reg & (0xffffffffULL << 28);
-		max_buses = 256;
-		break;
-	case 1: /* 128M */
-		pciexbar = pciexbar_reg & (0xffffffffULL << 27);
-		max_buses = 128;
-		break;
-	case 2: /* 64M */
-		pciexbar = pciexbar_reg & (0xffffffffULL << 26);
-		max_buses = 64;
-		break;
-	default: /* RSVD */
-		return current;
-	}
-
-	if (!pciexbar)
-		return current;
+	const int max_buses = length / MiB;
 
 	current += acpi_create_mcfg_mmconfig((acpi_mcfg_mmconfig_t *) current, pciexbar, 0, 0,
-			max_buses - 1);
+					     max_buses - 1);
 
 	return current;
 }
 
-
 static unsigned long acpi_create_igfx_rmrr(const unsigned long current)
 {
 	const u32 base_mask = ~(u32)(MiB - 1);
diff --git a/src/northbridge/intel/sandybridge/northbridge.c b/src/northbridge/intel/sandybridge/northbridge.c
index 8f1db97..e670c09 100644
--- a/src/northbridge/intel/sandybridge/northbridge.c
+++ b/src/northbridge/intel/sandybridge/northbridge.c
@@ -40,7 +40,7 @@
 static const int legacy_hole_base_k = 0xa0000 / 1024;
 static const int legacy_hole_size_k = 384;
 
-static int decode_pcie_bar(u32 *const base, u32 *const len)
+int decode_pcie_bar(u32 *const base, u32 *const len)
 {
 	*base = 0;
 	*len = 0;
diff --git a/src/northbridge/intel/sandybridge/sandybridge.h b/src/northbridge/intel/sandybridge/sandybridge.h
index 264d1e2..72724a3 100644
--- a/src/northbridge/intel/sandybridge/sandybridge.h
+++ b/src/northbridge/intel/sandybridge/sandybridge.h
@@ -177,6 +177,8 @@
 void report_memory_config(void);
 enum platform_type get_platform_type(void);
 
+int decode_pcie_bar(u32 *const base, u32 *const len);
+
 #include <device/device.h>
 
 struct acpi_rsdp;