x86 PAT: consolidate old memtype new memtype check into a function
Impact: cleanup
Move the new memtype old memtype allowed check to header so that is can be
shared by other users. Subsequent patch uses this in pat.c in remap_pfn_range()
code path. No functionality change in this patch.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 83e69f4..06bbcbd 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -341,6 +341,25 @@
#define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)
+static inline int is_new_memtype_allowed(unsigned long flags,
+ unsigned long new_flags)
+{
+ /*
+ * Certain new memtypes are not allowed with certain
+ * requested memtype:
+ * - request is uncached, return cannot be write-back
+ * - request is write-combine, return cannot be write-back
+ */
+ if ((flags == _PAGE_CACHE_UC_MINUS &&
+ new_flags == _PAGE_CACHE_WB) ||
+ (flags == _PAGE_CACHE_WC &&
+ new_flags == _PAGE_CACHE_WB)) {
+ return 0;
+ }
+
+ return 1;
+}
+
#ifndef __ASSEMBLY__
/* Indicate that x86 has its own track and untrack pfn vma functions */
#define __HAVE_PFNMAP_TRACKING
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index f884740..5ead808 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -314,17 +314,7 @@
return retval;
if (flags != new_flags) {
- /*
- * Do not fallback to certain memory types with certain
- * requested type:
- * - request is uncached, return cannot be write-back
- * - request is uncached, return cannot be write-combine
- * - request is write-combine, return cannot be write-back
- */
- if ((flags == _PAGE_CACHE_UC_MINUS &&
- (new_flags == _PAGE_CACHE_WB)) ||
- (flags == _PAGE_CACHE_WC &&
- new_flags == _PAGE_CACHE_WB)) {
+ if (!is_new_memtype_allowed(flags, new_flags)) {
free_memtype(addr, addr+len);
return -EINVAL;
}