x86_64: check MSR to get MMCONFIG for AMD Family 10h

so even booting kernel with acpi=off or even MCFG is not there, we still can
use MMCONFIG.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Greg KH <greg@kroah.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/pci/mmconfig-shared.c

@@ -100,33 +100,96 @@ static const char __init *pci_mmcfg_intel_945(void)
 	return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
 }
 
+static const char __init *pci_mmcfg_amd_fam10h(void)
+{
+	u32 low, high, address;
+	u64 base, msr;
+	int i;
+	unsigned segnbits = 0, busnbits;
+
+	address = MSR_FAM10H_MMIO_CONF_BASE;
+	if (rdmsr_safe(address, &low, &high))
+		return NULL;
+
+	msr = high;
+	msr <<= 32;
+	msr |= low;
+
+	/* mmconfig is not enable */
+	if (!(msr & FAM10H_MMIO_CONF_ENABLE))
+		return NULL;
+
+	base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
+
+	busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
+			 FAM10H_MMIO_CONF_BUSRANGE_MASK;
+
+	/*
+	 * only handle bus 0 ?
+	 * need to skip it
+	 */
+	if (!busnbits)
+		return NULL;
+
+	if (busnbits > 8) {
+		segnbits = busnbits - 8;
+		busnbits = 8;
+	}
+
+	pci_mmcfg_config_num = (1 << segnbits);
+	pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]) *
+				   pci_mmcfg_config_num, GFP_KERNEL);
+	if (!pci_mmcfg_config)
+		return NULL;
+
+	for (i = 0; i < (1 << segnbits); i++) {
+		pci_mmcfg_config[i].address = base + (1<<28) * i;
+		pci_mmcfg_config[i].pci_segment = i;
+		pci_mmcfg_config[i].start_bus_number = 0;
+		pci_mmcfg_config[i].end_bus_number = (1 << busnbits) - 1;
+	}
+
+	return "AMD Family 10h NB";
+}
+
 struct pci_mmcfg_hostbridge_probe {
+	u32 bus;
+	u32 devfn;
 	u32 vendor;
 	u32 device;
 	const char *(*probe)(void);
 };
 
 static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
-	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
-	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
+	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
+	  PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
+	{ 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
+	  PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
+	{ 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
+	  0x1200, pci_mmcfg_amd_fam10h },
+	{ 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
+	  0x1200, pci_mmcfg_amd_fam10h },
 };
 
 static int __init pci_mmcfg_check_hostbridge(void)
 {
 	u32 l;
+	u32 bus, devfn;
 	u16 vendor, device;
 	int i;
 	const char *name;
 
-	pci_direct_conf1.read(0, 0, PCI_DEVFN(0,0), 0, 4, &l);
-	vendor = l & 0xffff;
-	device = (l >> 16) & 0xffff;
-
 	pci_mmcfg_config_num = 0;
 	pci_mmcfg_config = NULL;
 	name = NULL;
 
 	for (i = 0; !name && i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
+		bus =  pci_mmcfg_probes[i].bus;
+		devfn = pci_mmcfg_probes[i].devfn;
+		pci_direct_conf1.read(0, bus, devfn, 0, 4, &l);
+		vendor = l & 0xffff;
+		device = (l >> 16) & 0xffff;
+
 		if (pci_mmcfg_probes[i].vendor == vendor &&
 		    pci_mmcfg_probes[i].device == device)
 			name = pci_mmcfg_probes[i].probe();