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| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2009-04-09 23:26:51 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-10 13:55:48 +0200 |
| commit | b6ff32d9aaeeeecf98f9a852d715569183585312 (patch) | |
| tree | cd7ae3c0d0e20d96874c95a36403f54720d05fa6 /arch/x86/mm/pat.c | |
| parent | x86, PAT: Changing memtype to WC ensuring no WB alias (diff) | |
| download | linux-b6ff32d9aaeeeecf98f9a852d715569183585312.tar.xz linux-b6ff32d9aaeeeecf98f9a852d715569183585312.zip | |
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: 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>
Diffstat (limited to 'arch/x86/mm/pat.c')
| -rw-r--r-- | arch/x86/mm/pat.c | 35 |
1 files changed, 13 insertions, 22 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 640339ee4fb2..8d3de9580508 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -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) |