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x86, PAT: Consolidate code in pat_x_mtrr_type() and reserve_memtype()

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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>
This commit is contained in:
Suresh Siddha 2009-04-09 14:26:51 -07:00 committed by Ingo Molnar
parent 3869c4aa18
commit b6ff32d9aa
2 changed files with 15 additions and 23 deletions
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3
arch/x86/mm/ioremap.c
View file

@ -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;

35
arch/x86/mm/pat.c
View file

@ -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);
}
/*
* 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 @@ 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)