x86: iommu: use symbolic constants, not hardcoded numbers

Move symbolic constants into gart.h, and use them instead of hardcoded
constant.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/asm-x86/gart.h b/include/asm-x86/gart.h
index 90958ed..248e577 100644
--- a/include/asm-x86/gart.h
+++ b/include/asm-x86/gart.h
@@ -5,6 +5,7 @@
 extern void no_iommu_init(void);
 extern int force_iommu, no_iommu;
 extern int iommu_detected;
+extern int agp_amd64_init(void);
 #ifdef CONFIG_GART_IOMMU
 extern void gart_iommu_init(void);
 extern void gart_iommu_shutdown(void);
@@ -31,4 +32,24 @@
 
 #endif
 
+/* PTE bits. */
+#define GPTE_VALID	1
+#define GPTE_COHERENT	2
+
+/* Aperture control register bits. */
+#define GARTEN		(1<<0)
+#define DISGARTCPU	(1<<4)
+#define DISGARTIO	(1<<5)
+
+/* GART cache control register bits. */
+#define INVGART		(1<<0)
+#define GARTPTEERR	(1<<1)
+
+/* K8 On-cpu GART registers */
+#define AMD64_GARTAPERTURECTL	0x90
+#define AMD64_GARTAPERTUREBASE	0x94
+#define AMD64_GARTTABLEBASE	0x98
+#define AMD64_GARTCACHECTL	0x9c
+#define AMD64_GARTEN		(1<<0)
+
 #endif