1 files changed, 19 insertions, 15 deletions

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 73fb469908c6..3d2661ca6542 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -30,6 +30,22 @@
 #include <asm/amd_nb.h>
 #include <asm/x86_init.h>
 
+/*
+ * Using 512M as goal, in case kexec will load kernel_big
+ * that will do the on-position decompress, and could overlap with
+ * with the gart aperture that is used.
+ * Sequence:
+ * kernel_small
+ * ==> kexec (with kdump trigger path or gart still enabled)
+ * ==> kernel_small (gart area become e820_reserved)
+ * ==> kexec (with kdump trigger path or gart still enabled)
+ * ==> kerne_big (uncompressed size will be big than 64M or 128M)
+ * So don't use 512M below as gart iommu, leave the space for kernel
+ * code for safe.
+ */
+#define GART_MIN_ADDR   (512ULL << 20)
+#define GART_MAX_ADDR   (1ULL   << 32)
+
 int gart_iommu_aperture;
 int gart_iommu_aperture_disabled __initdata;
 int gart_iommu_aperture_allowed __initdata;
@@ -70,21 +86,9 @@ static u32 __init allocate_aperture(void)
          * memory. Unfortunately we cannot move it up because that would
          * make the IOMMU useless.
          */
-        /*
-         * using 512M as goal, in case kexec will load kernel_big
-         * that will do the on position decompress, and  could overlap with
-         * that position with gart that is used.
-         * sequende:
-         * kernel_small
-         * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
-         * ==> kernel_small(gart area become e820_reserved)
-         * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
-         * ==> kerne_big (uncompressed size will be big than 64M or 128M)
-         * so don't use 512M below as gart iommu, leave the space for kernel
-         * code for safe
-         */
-        addr = memblock_find_in_range(0, 1ULL<<32, aper_size, 512ULL<<20);
-        if (addr == MEMBLOCK_ERROR || addr + aper_size > 0xffffffff) {
+        addr = memblock_find_in_range(GART_MIN_ADDR, GART_MAX_ADDR,
+                                      aper_size, aper_size);
+        if (addr == MEMBLOCK_ERROR || addr + aper_size > GART_MAX_ADDR) {
                 printk(KERN_ERR
                         "Cannot allocate aperture memory hole (%lx,%uK)\n",
                                 addr, aper_size>>10);