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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] ARM: include: asm: use 'int' instead of 'unsigned long' for normal register variables within atomic.h
Date: Tue, 1 Oct 2013 10:01:19 +0100	[thread overview]
Message-ID: <20131001090119.GA17629@mudshark.cambridge.arm.com> (raw)
In-Reply-To: <524A2DE7.8040208@asianux.com>

On Tue, Oct 01, 2013 at 03:05:27AM +0100, Chen Gang wrote:
> On 10/01/2013 12:11 AM, Will Deacon wrote:
> > On Sun, Sep 29, 2013 at 04:52:28AM +0100, Chen Gang wrote:
> >> "arc/arm" will be never on 64-bit, it is mainly on 32-bit (may also can
> >> be on 16-bit).
> >>
> >> So better to use 'int' instead of 'unsigned long' for normal register
> >> variable (on 16-bit, 'int' is allowed to be 16-bit, so historically,
> >> often use 'int' for normal register variables).
> > 
> > This commit message doesn't make a blind bit of sense! arch/arm/ is a 32-bit
> > architecture in the sense that int will always be 32-bit there. This patch
> > is just a cosmetic change, bringing our atomic_t manipulation code inline
> > with the atomic_t type definition.
> > 
> 
> OK, thanks. That means: "arm means arm 32-bit, arm64 means arm 64-bit.
> The current Linux kernel main line does not support arm 16-bit".
> 
> Since "bringing our atomic_t ... with the atomic_t type definition", can
> we use 'atomic_t" instead of 'unsigned long'?
> 
> And can we use 'atomic64_t" instead of 'unsigned long' in atomic64_*()?

That's probably a bit dodgy, since they are typedefs to compound types
which, if ever extended, would fall to bits if we tried to pack them into a
single register.

Will

  reply	other threads:[~2013-10-01  9:01 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-21 11:06 [PATCH] ARM: include: asm: atomic.h: use type cast 's64' for the return value of atomic64_add_return() Chen Gang
2013-09-24  9:30 ` Will Deacon
2013-09-24 10:27   ` Russell King - ARM Linux
2013-09-24 10:37     ` Chen Gang
2013-09-24 10:30   ` Chen Gang
2013-09-25  2:25   ` [PATCH v2] ARM: include: asm: use 'long long' instead of 'u64' within atomic.h Chen Gang
2013-09-25 16:07     ` Will Deacon
2013-09-26  2:00       ` Chen Gang
2013-09-26 10:04         ` Will Deacon
2013-09-26 11:03           ` Chen Gang
2013-09-27 11:06             ` Will Deacon
2013-09-27 11:36               ` Chen Gang
2013-09-29  3:43               ` [PATCH 0/2] ARM: include: asm: change functions' and variables' types in atomic.h Chen Gang
2013-09-29  3:43                 ` [PATCH 1/2] ARM: include: asm: use 'long long' instead of 'u64' within atomic.h Chen Gang
2013-09-29  3:52                   ` [PATCH 2/2] ARM: include: asm: use 'int' instead of 'unsigned long' for normal register variables " Chen Gang
2013-09-30 16:11                     ` Will Deacon
2013-10-01  2:05                       ` Chen Gang
2013-10-01  9:01                         ` Will Deacon [this message]
2013-10-01 12:03                           ` Chen Gang
2013-10-02 10:41                             ` Will Deacon
2013-10-02 15:19                               ` Chen Gang
2013-10-03 10:05                                 ` Chen Gang
2013-10-03 16:32                                   ` Will Deacon
2013-10-04  9:51                                     ` Chen Gang
2013-10-04 15:37                                       ` Will Deacon
2013-10-04 15:42                                         ` Will Deacon
2013-10-04 23:55                                           ` Chen Gang
2013-10-05  0:11                                             ` Chen Gang
2013-10-08  4:10                                               ` Chen Gang
2013-10-08 10:34                                                 ` Will Deacon
2013-10-08 10:56                                                   ` [PATCH v2 0/2] ARM: include: asm: change functions' and variables' types in atomic.h Chen Gang
2013-10-08 10:57                                                     ` [PATCH v2 1/2] ARM: include: asm: use 'long long' instead of 'u64' within atomic.h Chen Gang
2013-10-08 10:59                                                       ` [PATCH v2 2/2] ARM: include: asm: use 'int' instead of 'unsigned long' for 'oldval' in atomic_cmpxchg() Chen Gang
2013-10-09 10:48                                                         ` Will Deacon
2013-10-10  0:56                                                           ` Chen Gang
2013-10-09 10:46                                                       ` [PATCH v2 1/2] ARM: include: asm: use 'long long' instead of 'u64' within atomic.h Will Deacon
2013-10-08 11:00                                                   ` [PATCH 2/2] ARM: include: asm: use 'int' instead of 'unsigned long' for normal register variables " Chen Gang
2013-10-08 10:33                                             ` Will Deacon
2013-10-08 11:29                                               ` Chen Gang
2013-10-08 17:49                                                 ` Will Deacon
2013-10-09  0:18                                                   ` Chen Gang
2013-10-09  1:22                                                     ` Chen Gang
2013-09-30 16:07                   ` [PATCH 1/2] ARM: include: asm: use 'long long' instead of 'u64' " Will Deacon
2013-10-01  2:09                     ` Chen Gang

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