x86/pci/mrst: force all pci config toward 0:0:0, 0:2:0 and 0:3:0 totype 1

[Bin Gao]

x86/pci/mrst: force all pci config access toward 0:0:0, 0:2:0 and 0:3:0 to type 1

For real pci devices 0:0:0, 0:2:0 and 0:3:0, there is either no pci shim, or
no guarantee of data correctness of offset 256-4k. So for whatever reason,
Linux kernel should not do MMCFG pci config access to those devices. Instead,
always use type 1 for those devices.

Signed-off-by: Bin Gao <bin.gao@xxxxxxxxxxxxxxx>
---
 arch/x86/pci/mrst.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/pci/mrst.c b/arch/x86/pci/mrst.c
index 6eb18c4..0e0fabf 100644
--- a/arch/x86/pci/mrst.c
+++ b/arch/x86/pci/mrst.c
@@ -141,6 +141,11 @@ static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn,
  */
 static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg)
 {
+	if (bus == 0 && (devfn == PCI_DEVFN(2, 0)
+				|| devfn == PCI_DEVFN(0, 0)
+				|| devfn == PCI_DEVFN(3, 0)))
+		return 1;
+
 	/* This is a workaround for A0 LNC bug where PCI status register does
 	 * not have new CAP bit set. can not be written by SW either.
 	 *
@@ -150,10 +155,7 @@ static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg)
 	 */
 	if (reg >= 0x100 || reg == PCI_STATUS || reg == PCI_HEADER_TYPE)
 		return 0;
-	if (bus == 0 && (devfn == PCI_DEVFN(2, 0)
-				|| devfn == PCI_DEVFN(0, 0)
-				|| devfn == PCI_DEVFN(3, 0)))
-		return 1;
+
 	return 0; /* langwell on others */
 }
 
-- 
1.7.4.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/