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-rw-r--r--arch/x86/mm/pat.c35
1 files changed, 13 insertions, 22 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 640339ee4fb2..8d3de9580508 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -182,10 +182,10 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)
u8 mtrr_type;
mtrr_type = mtrr_type_lookup(start, end);
- if (mtrr_type == MTRR_TYPE_UNCACHABLE)
- return _PAGE_CACHE_UC;
- if (mtrr_type == MTRR_TYPE_WRCOMB)
- return _PAGE_CACHE_WC;
+ if (mtrr_type != MTRR_TYPE_WRBACK)
+ return _PAGE_CACHE_UC_MINUS;
+
+ return _PAGE_CACHE_WB;
}
return req_type;
@@ -352,23 +352,13 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
return 0;
}
- if (req_type == -1) {
- /*
- * Call mtrr_lookup to get the type hint. This is an
- * optimization for /dev/mem mmap'ers into WB memory (BIOS
- * tools and ACPI tools). Use WB request for WB memory and use
- * UC_MINUS otherwise.
- */
- u8 mtrr_type = mtrr_type_lookup(start, end);
-
- if (mtrr_type == MTRR_TYPE_WRBACK)
- actual_type = _PAGE_CACHE_WB;
- else
- actual_type = _PAGE_CACHE_UC_MINUS;
- } else {
- actual_type = pat_x_mtrr_type(start, end,
- req_type & _PAGE_CACHE_MASK);
- }
+ /*
+ * Call mtrr_lookup to get the type hint. This is an
+ * optimization for /dev/mem mmap'ers into WB memory (BIOS
+ * tools and ACPI tools). Use WB request for WB memory and use
+ * UC_MINUS otherwise.
+ */
+ actual_type = pat_x_mtrr_type(start, end, req_type & _PAGE_CACHE_MASK);
if (new_type)
*new_type = actual_type;
@@ -587,7 +577,8 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
if (flags != -1) {
retval = reserve_memtype(offset, offset + size, flags, NULL);
} else {
- retval = reserve_memtype(offset, offset + size, -1, &flags);
+ retval = reserve_memtype(offset, offset + size,
+ _PAGE_CACHE_WB, &flags);
}
if (retval < 0)
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