[PATCH] x86: fix amd64-agp aperture validation

Under CONFIG_DISCONTIGMEM, assuming that a !pfn_valid() implies all
subsequent pfn-s are also invalid is wrong. Thus replace this by
explicitly checking against the E820 map.

AK: make e820 on x86-64 not initdata

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c
index 485720486d60..c9f0f250d78f 100644
--- a/drivers/char/agp/amd64-agp.c
+++ b/drivers/char/agp/amd64-agp.c
@@ -14,6 +14,7 @@
 #include <linux/agp_backend.h>
 #include <linux/mmzone.h>
 #include <asm/page.h>           /* PAGE_SIZE */
+#include <asm/e820.h>
 #include <asm/k8.h>
 #include "agp.h"
 
@@ -259,7 +260,6 @@ static const struct agp_bridge_driver amd_8151_driver = {
 /* Some basic sanity checks for the aperture. */
 static int __devinit aperture_valid(u64 aper, u32 size)
 {
-        u32 pfn, c;
         if (aper == 0) {
                 printk(KERN_ERR PFX "No aperture\n");
                 return 0;
@@ -272,14 +272,9 @@ static int __devinit aperture_valid(u64 aper, u32 size)
                 printk(KERN_ERR PFX "Aperture out of bounds\n");
                 return 0;
         }
-        pfn = aper >> PAGE_SHIFT;
-        for (c = 0; c < size/PAGE_SIZE; c++) {
-                if (!pfn_valid(pfn + c))
-                        break;
-                if (!PageReserved(pfn_to_page(pfn + c))) {
-                        printk(KERN_ERR PFX "Aperture pointing to RAM\n");
-                        return 0;
-                }
+        if (e820_any_mapped(aper, aper + size, E820_RAM)) {
+                printk(KERN_ERR PFX "Aperture pointing to RAM\n");
+                return 0;
         }
 
         /* Request the Aperture. This catches cases when someone else