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Commit afc7d20c authored by venkatesh.pallipadi@intel.com's avatar venkatesh.pallipadi@intel.com Committed by Ingo Molnar
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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: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a3670613

arch/x86/include/asm/pgtable.h

+19 −0
Original line number Original line Diff line number Diff line
@@ -341,6 +341,25 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) 




#define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)

#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__

#ifndef __ASSEMBLY__

/* Indicate that x86 has its own track and untrack pfn vma functions */

/* Indicate that x86 has its own track and untrack pfn vma functions */

#define __HAVE_PFNMAP_TRACKING

#define __HAVE_PFNMAP_TRACKING

arch/x86/pci/i386.c

+1 −11
Original line number Original line Diff line number Diff line
@@ -314,17 +314,7 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, 
		return retval;

		return retval;





	if (flags != new_flags) {

	if (flags != new_flags) {

		/*

		if (!is_new_memtype_allowed(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)) {

			free_memtype(addr, addr+len);

			free_memtype(addr, addr+len);

			return -EINVAL;

			return -EINVAL;

		}

		}