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Date: Fri, 06 Jul 2012 15:07:48 +0100 From: "Jan Beulich" <JBeulich@...e.com> To: <mingo@...e.hu>, <tglx@...utronix.de>, <hpa@...or.com> Cc: <linux-kernel@...r.kernel.org> Subject: [PATCH] x86: 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 t 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@...e.com> --- arch/x86/kernel/cpu/mtrr/cleanup.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- 3.5-rc5/arch/x86/kernel/cpu/mtrr/cleanup.c +++ 3.5-rc5-x86-mtrr-cleanup-types/arch/x86/kernel/cpu/mtrr/cleanup.c @@ -258,11 +258,11 @@ range_to_mtrr(unsigned int reg, unsigned /* 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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