[PATCH] x86: skip it if Fam 10h only handle bus 0

[Yinghai Lu <Yinghai.Lu@Sun.COM>]

need to apply after
	x86_64: check MSR to get MMCONFIG for AMD Family 10h Opteron v3

some BIOS only let AMD fam 10h handle bus0, and nvidia mcp55/ck804
to handle other buses. at that case MCFG will cover all over them.

this patch will skip it so to use MCFG later.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>

Index: linux-2.6/arch/x86/pci/mmconfig-shared.c
===================================================================
--- linux-2.6.orig/arch/x86/pci/mmconfig-shared.c
+++ linux-2.6/arch/x86/pci/mmconfig-shared.c
@@ -123,6 +123,14 @@ static const char __init *pci_mmcfg_amd_
 
 	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;