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Commit b6ff32d9 authored by Suresh Siddha's avatar Suresh Siddha Committed by Ingo Molnar
Browse files

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: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.939936000@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 3869c4aa

arch/x86/mm/ioremap.c

+2 −1
Original line number Diff line number Diff line
@@ -375,7 +375,8 @@ static void __iomem *ioremap_default(resource_size_t phys_addr, 
	 * - UC_MINUS for non-WB-able memory with no other conflicting mappings

	 * - Inherit from confliting mappings otherwise

	 */

	err = reserve_memtype(phys_addr, phys_addr + size, -1, &flags);

	err = reserve_memtype(phys_addr, phys_addr + size,

				_PAGE_CACHE_WB, &flags);

	if (err < 0)

		return NULL;

arch/x86/mm/pat.c

+13 −22
Original line number Diff line number Diff line
@@ -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);

	}

	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)