x86: vSMP: Fix is_vsmp_box()

is_vsmp_box() currently does not work on vSMPowered systems,  as pci cfg
space is not read correctly -- This patch fixes it.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c
index a00961d42e75..eb25584c54c3 100644
--- a/arch/x86/kernel/vsmp_64.c
+++ b/arch/x86/kernel/vsmp_64.c
@@ -84,8 +84,10 @@ int is_vsmp_box(void)
                 return vsmp;
 
         /* Check if we are running on a ScaleMP vSMP box */
-        if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) ==
-             (PCI_VENDOR_ID_SCALEMP || (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16)))
+        if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) ==
+             PCI_VENDOR_ID_SCALEMP) &&
+            (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) ==
+            PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
                 vsmp = 1;
 
         return vsmp;