From: gang.chen@asianux•com (Chen Gang)
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, 01 Oct 2013 10:05:27 +0800 [thread overview]
Message-ID: <524A2DE7.8040208@asianux.com> (raw)
In-Reply-To: <20130930161149.GI26036@mudshark.cambridge.arm.com>
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_*()?
>> @@ -297,7 +297,7 @@ static inline void atomic64_set(atomic64_t *v, long
>> long i)
>> static inline void atomic64_add(long long i, atomic64_t *v)
>> {
>> long long result;
>> - unsigned long tmp;
>> + int tmp;
>
> Please leave the atomic64_* functions alone here; the reasoning I explained
> above doesn't apply to them. Whilst int may work, it seems gratuitous to
> make this change for no reason.
>
For 32-bit, it seems we can not use 'atomic64_t' instead of 'unsigned
long' in atomic64_*(). ;-)
For 32-bit, the original 'unsigned long' in atomic64_add() is correct,
or is also a bug?
> Will
>
>
In fact, if arm only for 32-bit, I really don't know why we need 'int'
instead of some 'unsigned long' (neither can let patch comment correct,
nor know which 'unsigned long' need be instead of). :-(
It seems we need be careful to not let this patch make new bug for arm.
Thanks.
--
Chen Gang
next prev parent reply other threads:[~2013-10-01 2:05 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 [this message]
2013-10-01 9:01 ` Will Deacon
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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