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| author | Jan Beulich <JBeulich@suse.com> | 2012-07-06 16:07:48 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-07-10 10:38:14 +0200 |
| commit | 1ba9a294141b106b7247649a5c3372d8284eca80 (patch) | |
| tree | cc99056968f74fb5ceaaae380548da3a72cd4f96 /arch/x86/kernel/cpu/mtrr | |
| parent | x86/copy_user_generic: Optimize copy_user_generic with CPU erms feature (diff) | |
| download | linux-1ba9a294141b106b7247649a5c3372d8284eca80.tar.xz linux-1ba9a294141b106b7247649a5c3372d8284eca80.zip | |
x86/mm/mtrr: Fix alignment determination in range_to_mtrr()
With the variable operated on being of "unsigned long" type,
neither ffs() nor fls() are suitable to use on them, as those
truncate their arguments to 32 bits. Using __ffs() and __fls()
respectively at once eliminates the need to subtract 1 from their
results.
Additionally, with the alignment value subsequently used as a
shift count, it must be enforced to be less than BITS_PER_LONG
(and on 64-bit there's no need for it to be any smaller).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/4FF70D54020000780008E179@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/cleanup.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c index bdda2e6c673b..35ffda5d0727 100644 --- a/arch/x86/kernel/cpu/mtrr/cleanup.c +++ b/arch/x86/kernel/cpu/mtrr/cleanup.c @@ -258,11 +258,11 @@ range_to_mtrr(unsigned int reg, unsigned long range_startk, /* Compute the maximum size with which we can make a range: */ if (range_startk) - max_align = ffs(range_startk) - 1; + max_align = __ffs(range_startk); else - max_align = 32; + max_align = BITS_PER_LONG - 1; - align = fls(range_sizek) - 1; + align = __fls(range_sizek); if (align > max_align) align = max_align; |