[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, 20 insertions, 0 deletions

diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index 31f4670ef740..829beec9247e 100644
--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -825,6 +825,26 @@ void __init limit_regions(unsigned long long size)
         print_memory_map("limit_regions endfunc");
 }
 
+/*
+ * This function checks if any part of the range <start,end> is mapped
+ * with type.
+ */
+int
+e820_any_mapped(u64 start, u64 end, unsigned type)
+{
+        int i;
+        for (i = 0; i < e820.nr_map; i++) {
+                const struct e820entry *ei = &e820.map[i];
+                if (type && ei->type != type)
+                        continue;
+                if (ei->addr >= end || ei->addr + ei->size <= start)
+                        continue;
+                return 1;
+        }
+        return 0;
+}
+EXPORT_SYMBOL_GPL(e820_any_mapped);
+
  /*
   * This function checks if the entire range <start,end> is mapped with type.
   *