From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 6/9] asm-generic/bitops/atomic.h: Rewrite using atomic_fetch_*
Date: Thu, 24 May 2018 13:47:39 +0100 [thread overview]
Message-ID: <20180524124734.GE8689@arm.com> (raw)
In-Reply-To: <20180524124410.GF12198@hirez.programming.kicks-ass.net>
On Thu, May 24, 2018 at 02:44:10PM +0200, Peter Zijlstra wrote:
> On Thu, May 24, 2018 at 11:59:43AM +0100, Will Deacon wrote:
> > +static inline void set_bit(unsigned int nr, volatile unsigned long *p)
> > {
> > + p += BIT_WORD(nr);
> > + atomic_long_fetch_or_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
> > }
> >
> > +static inline void clear_bit(unsigned int nr, volatile unsigned long *p)
> > {
> > + p += BIT_WORD(nr);
> > + atomic_long_fetch_andnot_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
> > }
> >
> > +static inline void change_bit(unsigned int nr, volatile unsigned long *p)
> > {
> > + p += BIT_WORD(nr);
> > + atomic_long_fetch_xor_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
> > }
>
> Why use the fetch variants here?
I noticed the same thing just now; I'll drop that and just use the
non-value-returning variants. It's shame that I can't do the same for
the lock.h unlock code, but we don't have non-returning release variants.
Will
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
linux-arm-kernel@lists.infradead.org,
yamada.masahiro@socionext.com
Subject: Re: [PATCH 6/9] asm-generic/bitops/atomic.h: Rewrite using atomic_fetch_*
Date: Thu, 24 May 2018 13:47:39 +0100 [thread overview]
Message-ID: <20180524124734.GE8689@arm.com> (raw)
In-Reply-To: <20180524124410.GF12198@hirez.programming.kicks-ass.net>
On Thu, May 24, 2018 at 02:44:10PM +0200, Peter Zijlstra wrote:
> On Thu, May 24, 2018 at 11:59:43AM +0100, Will Deacon wrote:
> > +static inline void set_bit(unsigned int nr, volatile unsigned long *p)
> > {
> > + p += BIT_WORD(nr);
> > + atomic_long_fetch_or_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
> > }
> >
> > +static inline void clear_bit(unsigned int nr, volatile unsigned long *p)
> > {
> > + p += BIT_WORD(nr);
> > + atomic_long_fetch_andnot_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
> > }
> >
> > +static inline void change_bit(unsigned int nr, volatile unsigned long *p)
> > {
> > + p += BIT_WORD(nr);
> > + atomic_long_fetch_xor_relaxed(BIT_MASK(nr), (atomic_long_t *)p);
> > }
>
> Why use the fetch variants here?
I noticed the same thing just now; I'll drop that and just use the
non-value-returning variants. It's shame that I can't do the same for
the lock.h unlock code, but we don't have non-returning release variants.
Will
next prev parent reply other threads:[~2018-05-24 12:47 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-24 10:59 [PATCH 0/9] Rewrite asm-generic/bitops/{atomic, lock}.h and use on arm64 Will Deacon
2018-05-24 10:59 ` [PATCH 0/9] Rewrite asm-generic/bitops/{atomic,lock}.h " Will Deacon
2018-05-24 10:59 ` [PATCH 1/9] h8300: Don't include linux/kernel.h in asm/atomic.h Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-07-22 13:58 ` Yoshinori Sato
2018-07-22 13:58 ` Yoshinori Sato
2018-05-24 10:59 ` [PATCH 2/9] m68k: Don't use asm-generic/bitops/lock.h Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-05-24 10:59 ` [PATCH 3/9] asm-generic: Move some macros from linux/bitops.h to a new bits.h file Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-05-24 10:59 ` [PATCH 4/9] openrisc: Don't pull in all of linux/bitops.h in asm/cmpxchg.h Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-05-24 10:59 ` [PATCH 5/9] sh: Don't pull in all of linux/bitops.h in asm/cmpxchg-xchg.h Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-05-24 10:59 ` [PATCH 6/9] asm-generic/bitops/atomic.h: Rewrite using atomic_fetch_* Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-05-24 12:44 ` Peter Zijlstra
2018-05-24 12:44 ` Peter Zijlstra
2018-05-24 12:47 ` Will Deacon [this message]
2018-05-24 12:47 ` Will Deacon
2018-05-24 13:09 ` Mark Rutland
2018-05-24 13:09 ` Mark Rutland
2018-05-24 22:06 ` Andrea Parri
2018-05-24 22:06 ` Andrea Parri
2018-05-24 22:32 ` Peter Zijlstra
2018-05-24 22:32 ` Peter Zijlstra
2018-05-24 10:59 ` [PATCH 7/9] asm-generic/bitops/lock.h: " Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-05-24 10:59 ` [PATCH 8/9] arm64: Replace our atomic/lock bitop implementations with asm-generic Will Deacon
2018-05-24 10:59 ` Will Deacon
2018-05-24 10:59 ` [PATCH 9/9] arm64: bitops: Include <asm-generic/bitops/ext2-atomic-setbit.h> Will Deacon
2018-05-24 10:59 ` Will Deacon
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