diff --git a/sys/amd64/pci/pci_cfgreg.c b/sys/amd64/pci/pci_cfgreg.c
index 3e29a58..39abfd4 100644
--- a/sys/amd64/pci/pci_cfgreg.c
+++ b/sys/amd64/pci/pci_cfgreg.c
@@ -90,9 +90,17 @@ pci_cfgregopen(void)
 
 	/*
 	 * Grope around in the PCI config space to see if this is a
-	 * chipset that is capable of doing memory-mapped config cycles.
+	 * northbridge that is capable of doing memory-mapped config cycles.
 	 * This also implies that it can do PCIe extended config cycles.
 	 */
+	if (cpu_vendor_id == CPU_VENDOR_AMD &&
+	    CPUID_TO_FAMILY(cpu_id) >= 0x10) {
+		pciebar = rdmsr(0xc0010058);
+		if ((pciebar & 0x1) != 0)
+			pcie_cfgregopen(pciebar & 0xfffffff00000ull, 0,
+			    (1ul << ((pciebar >> 2) & 0xf)) - 1);
+		return (1);
+	}
 
 	/* Check for supported chipsets */
 	vid = pci_cfgregread(0, 0, 0, PCIR_VENDOR, 2);
@@ -317,13 +325,19 @@ pciereg_cfgread(int bus, unsigned slot, unsigned func, unsigned reg,
 
 	switch (bytes) {
 	case 4:
-		data = *(volatile uint32_t *)(va);
+//		data = *(volatile uint32_t *)(va);
+		__asm __volatile("mov %1, %%eax" : "=a" (data)
+		    : "m" (*(uint32_t *) va));
 		break;
 	case 2:
-		data = *(volatile uint16_t *)(va);
+//		data = *(volatile uint16_t *)(va);
+		__asm __volatile("movzwl %1, %%eax" : "=a" (data)
+		    : "m" (*(uint16_t *) va));
 		break;
 	case 1:
-		data = *(volatile uint8_t *)(va);
+//		data = *(volatile uint8_t *)(va);
+		__asm __volatile("movzbl %1, %%eax" : "=a" (data)
+		    : "m" (*(uint8_t *) va));
 		break;
 	}
 
@@ -344,13 +358,19 @@ pciereg_cfgwrite(int bus, unsigned slot, unsigned func, unsigned reg, int data,
 
 	switch (bytes) {
 	case 4:
-		*(volatile uint32_t *)(va) = data;
+//		*(volatile uint32_t *)(va) = data;
+		__asm __volatile("mov %%eax, %0" : "=m" (*(uint32_t *) va)
+		    : "a" (data));
 		break;
 	case 2:
-		*(volatile uint16_t *)(va) = data;
+//		*(volatile uint16_t *)(va) = data;
+		__asm __volatile("mov %%ax, %0" : "=m" (*(uint16_t *) va)
+		    : "a" (data));
 		break;
 	case 1:
-		*(volatile uint8_t *)(va) = data;
+//		*(volatile uint8_t *)(va) = data;
+		__asm __volatile("mov %%al, %0" : "=m" (*(uint8_t *) va)
+		    : "a" (data));
 		break;
 	}
 }