Merge branches 'x86/asm', 'x86/cleanups', 'x86/cpudetect', 'x86/debug', 'x86/doc...

[linux-2.6-omap-h63xx.git] / arch / x86 / mm / pat.c

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 430cb44dd3f4b03864972ad3e143ff9f80e5604b..9127e31c726866d462d0da61d03ceade383ced4e 100644 (file)
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -342,11 +342,23 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
                                              req_type & _PAGE_CACHE_MASK);
        }
 
-       is_range_ram = pagerange_is_ram(start, end);
-       if (is_range_ram == 1)
-               return reserve_ram_pages_type(start, end, req_type, new_type);
-       else if (is_range_ram < 0)
-               return -EINVAL;
+       if (new_type)
+               *new_type = actual_type;
+
+       /*
+        * For legacy reasons, some parts of the physical address range in the
+        * legacy 1MB region is treated as non-RAM (even when listed as RAM in
+        * the e820 tables).  So we will track the memory attributes of this
+        * legacy 1MB region using the linear memtype_list always.
+        */
+       if (end >= ISA_END_ADDRESS) {
+               is_range_ram = pagerange_is_ram(start, end);
+               if (is_range_ram == 1)
+                       return reserve_ram_pages_type(start, end, req_type,
+                                                     new_type);
+               else if (is_range_ram < 0)
+                       return -EINVAL;
+       }
 
        new  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
        if (!new)
@@ -356,9 +368,6 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
        new->end        = end;
        new->type       = actual_type;
 
-       if (new_type)
-               *new_type = actual_type;
-
        spin_lock(&memtype_lock);
 
        if (cached_entry && start >= cached_start)
@@ -446,11 +455,19 @@ int free_memtype(u64 start, u64 end)
        if (is_ISA_range(start, end - 1))
                return 0;
 
-       is_range_ram = pagerange_is_ram(start, end);
-       if (is_range_ram == 1)
-               return free_ram_pages_type(start, end);
-       else if (is_range_ram < 0)
-               return -EINVAL;
+       /*
+        * For legacy reasons, some parts of the physical address range in the
+        * legacy 1MB region is treated as non-RAM (even when listed as RAM in
+        * the e820 tables).  So we will track the memory attributes of this
+        * legacy 1MB region using the linear memtype_list always.
+        */
+       if (end >= ISA_END_ADDRESS) {
+               is_range_ram = pagerange_is_ram(start, end);
+               if (is_range_ram == 1)
+                       return free_ram_pages_type(start, end);
+               else if (is_range_ram < 0)
+                       return -EINVAL;
+       }
 
        spin_lock(&memtype_lock);
        list_for_each_entry(entry, &memtype_list, nd) {