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Commit dd0c7c49 authored by Andreas Herrmann's avatar Andreas Herrmann Committed by Ingo Molnar
Browse files

x86: shrink pat_x_mtrr_type to its essentials 



Signed-off-by: default avatarAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh B Siddha <suresh.b.siddha@intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 6cf514fc

arch/x86/mm/pat.c

+11 −19
Original line number Diff line number Diff line
@@ -161,29 +161,21 @@ static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */ 
 */

static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)

{

	u8 mtrr_type;



	/*

	 * We return the PAT request directly for types where PAT takes

	 * precedence with respect to MTRR and for UC_MINUS.

	 * Consistency checks with other PAT requests is done later

	 * while going through memtype list.

	 */

	if (req_type == _PAGE_CACHE_WC ||

	    req_type == _PAGE_CACHE_UC_MINUS ||

	    req_type == _PAGE_CACHE_UC)

		return req_type;



	/*

	 * Look for MTRR hint to get the effective type in case where PAT

	 * request is for WB.

	 */

	if (req_type == _PAGE_CACHE_WB) {

		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;

	return _PAGE_CACHE_WB;

	}



	return req_type;

}



/*