Subject: Re: [PATCH 0/2] locking/qspinlock: Break qspinlock_types.h header loop

From: Vineet Gupta <[email-masked]>
Date: Thu, 6 Aug 2020 03:37:31 +0000

On 7/30/20 12:50 AM, Herbert Xu wrote:
> On Thu, Jul 30, 2020 at 10:47:16AM +0300, Andy Shevchenko wrote:
>> We may ask Synopsys folks to look at this as well.
>> Vineet, any ideas if we may unify ATOMIC64_INIT() across the architectures?
> I don't think there is any technical difficulty.  The custom
> atomic64_t simply adds an alignment requirement so the initialisor
> remains the same.

Exactly so.

FWIW the alignment requirement is because ARC ABI allows 64-bit data to be 32-bit
aligned provided hardware deals fine with 4 byte aligned for the non-atomic
double-load/store LDD/STD instructions. The 64-bit alignement however is required
for atomic double load/store LLOCKD/SCONDD instructions hence the definition of
ARC atomic64_t

-Vineet