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-rw-r--r--arch/x86/mm/pat.c43
1 files changed, 30 insertions, 13 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 8b08fb955274..7b61036427df 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -333,11 +333,23 @@ 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)
@@ -347,9 +359,6 @@ 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)
@@ -437,11 +446,19 @@ 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) {