x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses

[sfrench/cifs-2.6.git] / arch / x86 / mm / pat.c

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 1555bd7d34493f972464e2df7e11a29f445ac600..3d0c83ef6aab98cde354b86f999eecfca3a38263 100644 (file)
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -512,6 +512,17 @@ static int free_ram_pages_type(u64 start, u64 end)
        return 0;
 }
 
+static u64 sanitize_phys(u64 address)
+{
+       /*
+        * When changing the memtype for pages containing poison allow
+        * for a "decoy" virtual address (bit 63 clear) passed to
+        * set_memory_X(). __pa() on a "decoy" address results in a
+        * physical address with bit 63 set.
+        */
+       return address & __PHYSICAL_MASK;
+}
+
 /*
  * req_type typically has one of the:
  * - _PAGE_CACHE_MODE_WB
@@ -533,6 +544,8 @@ int reserve_memtype(u64 start, u64 end, enum page_cache_mode req_type,
        int is_range_ram;
        int err = 0;
 
+       start = sanitize_phys(start);
+       end = sanitize_phys(end);
        BUG_ON(start >= end); /* end is exclusive */
 
        if (!pat_enabled()) {
@@ -609,6 +622,9 @@ int free_memtype(u64 start, u64 end)
        if (!pat_enabled())
                return 0;
 
+       start = sanitize_phys(start);
+       end = sanitize_phys(end);
+
        /* Low ISA region is always mapped WB. No need to track */
        if (x86_platform.is_untracked_pat_range(start, end))
                return 0;