intel-iommu: Use symbolic values instead of magic numbers in Lenovo w/a

Commit 9eecabcb9a924f1e11ba670365fd4babe423045c ("intel-iommu: Abort
IOMMU setup for igfx if BIOS gave no shadow GTT space") uses a bunch of
magic numbers. Provide #defines for those to make it look slightly saner.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index dee88c6..4dfce3d 100644 (file)
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -3761,14 +3761,24 @@ static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)
 
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf);
 
+#define GGC 0x52
+#define GGC_MEMORY_SIZE_MASK   (0xf << 8)
+#define GGC_MEMORY_SIZE_NONE   (0x0 << 8)
+#define GGC_MEMORY_SIZE_1M     (0x1 << 8)
+#define GGC_MEMORY_SIZE_2M     (0x3 << 8)
+#define GGC_MEMORY_VT_ENABLED  (0x8 << 8)
+#define GGC_MEMORY_SIZE_2M_VT  (0x9 << 8)
+#define GGC_MEMORY_SIZE_3M_VT  (0xa << 8)
+#define GGC_MEMORY_SIZE_4M_VT  (0xb << 8)
+
 static void __devinit quirk_calpella_no_shadow_gtt(struct pci_dev *dev)
 {
        unsigned short ggc;
 
-       if (pci_read_config_word(dev, 0x52, &ggc))
+       if (pci_read_config_word(dev, GGC, &ggc))
                return;
 
-       if (!(ggc & 0x800)) {
+       if (!(ggc & GGC_MEMORY_VT_ENABLED)) {
                printk(KERN_INFO "DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics\n");
                dmar_map_gfx = 0;
        }