x86, PAT: Consolidate code in pat_x_mtrr_type() and reserve_memtype()
Fix pat_x_mtrr_type() to use UC_MINUS when the mtrr type return UC. This
is to be consistent with ioremap() and ioremap_nocache() which uses
UC_MINUS.
Consolidate the code such that reserve_memtype() also uses
pat_x_mtrr_type() when the caller doesn't specify any special attribute
(non WB attribute).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.939936000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 640339e..8d3de95 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -182,10 +182,10 @@
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 @@
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 @@
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)