Messages in this thread | | | Date | Sun, 5 Nov 2017 16:53:34 +0100 | From | Heiko Carstens <> | Subject | Re: [tip:x86/fpu] bitops: Add clear/set_bit32() to linux/bitops.h |
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On Tue, Oct 17, 2017 at 09:21:46AM -0700, tip-bot for Andi Kleen wrote: > Commit-ID: cbe96375025e14fc76f9ed42ee5225120d7210f8 > Gitweb: https://git.kernel.org/tip/cbe96375025e14fc76f9ed42ee5225120d7210f8 > Author: Andi Kleen <ak@linux.intel.com> > AuthorDate: Fri, 13 Oct 2017 14:56:41 -0700 > Committer: Ingo Molnar <mingo@kernel.org> > CommitDate: Tue, 17 Oct 2017 17:14:56 +0200 > > bitops: Add clear/set_bit32() to linux/bitops.h > > Add two simple wrappers around set_bit/clear_bit() that accept > the common case of an u32 array. This avoids writing > casts in all callers. > > Signed-off-by: Andi Kleen <ak@linux.intel.com> > Reviewed-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Peter Zijlstra <peterz@infradead.org> > Link: http://lkml.kernel.org/r/20171013215645.23166-2-andi@firstfloor.org > Signed-off-by: Ingo Molnar <mingo@kernel.org> > --- > include/linux/bitops.h | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+)
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> + * set_bit32 - Set a bit in memory for u32 array > + * @nr: Bit to clear > + * @addr: u32 * address of bitmap > + * > + * Same as set_bit, but avoids needing casts for u32 arrays. > + */ > + > +static __always_inline void set_bit32(long nr, volatile u32 *addr) > +{ > + set_bit(nr, (volatile unsigned long *)addr); > +}
This does not work at all on 64 bit big endian machines. If e.g. the array would contain only one 32 bit member set_bit() would write to whatever is behind the array.
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