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: Fri, 04 Oct 2013 17:51:56 +0800 [thread overview]
Message-ID: <524E8FBC.2080200@asianux.com> (raw)
In-Reply-To: <20131003163200.GE7408@mudshark.cambridge.arm.com>
On 10/04/2013 12:32 AM, Will Deacon wrote:
> On Thu, Oct 03, 2013 at 11:05:31AM +0100, Chen Gang wrote:
>> If need send patch v2 for it, I should try (if so, need patch 1 also
>> send again?).
>
> Almost, comments below.
>
>>> So the related patch is below (still based on Patch 1):
>>>
>>> -----------------------------patch begin--------------------------------
>>>
>>> arm/include/asm/atomic.h: use 'int' instead of 'unsigned long' for 'oldval' in atomic_cmpxchg().
>>>
>>> For atomic_cmpxchg(), the type of 'oldval' need be 'int' to match the
>>> type of "*ptr" (used by 'ldrex' instruction) and 'old' (used by 'teq'
>>> instruction).
>>>
>>>
>>> Signed-off-by: Chen Gang <gang.chen@asianux•com>
>>> ---
>>> arch/arm/include/asm/atomic.h | 3 ++-
>>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
>>> index a715ac0..9ee7e01 100644
>>> --- a/arch/arm/include/asm/atomic.h
>>> +++ b/arch/arm/include/asm/atomic.h
>>> @@ -114,7 +114,8 @@ static inline int atomic_sub_return(int i, atomic_t *v)
>>>
>>> static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
>>> {
>>> - unsigned long oldval, res;
>>> + int oldval;
>>> + unsigned long res;
>>>
>>> smp_mb();
>
> I think you should also fix atomic_clear_mask to take (unsigned int mask,
> atomic_t *v). That would require a third patch fixing asm-generic, where
> atomic_clear_mask and atomic_set_mask have different types for the mask
> parameter.
>
> The problem with arm64 is that we're using *unsigned long* for 32-bit
> clear_mask, which is definitely wrong because it's 64-bit (another patch to
> fix this!).
>
At least, that is not a bug.
In fact, in my opinion, atomic_set/clear_mask() can be for both 32-bit
and 64-bit (no 'atomic64_set/clear_mask' in 'asm-generic').
> Finally, is atomic_clear_mask even used anywhere outside of
> drivers/s390/scsi/? If not, perhaps we can just drop this function from arm
> and arm64 after all.
>
Please see my original patch which may related for our discussion:
https://lkml.org/lkml/2013/6/9/4
In fact, that already included my opinion which may related with our
discussion, and has get acked-by for s390, but still suspending :-(
> Will
>
>
Thanks.
--
Chen Gang
next prev parent reply other threads:[~2013-10-04 9:51 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
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 [this message]
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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