Re: [PATCH 13/17] RISC-V: Add include subdirectory

From: Peter Zijlstra
Date: Wed Jun 07 2017 - 08:59:02 EST


On Wed, Jun 07, 2017 at 02:36:27PM +0200, Peter Zijlstra wrote:
> Which (pending the sub confusion) will generate the entire set of:
>
> atomic_add, atomic_add_return{_relaxed,_acquire,_release,} atomic_fetch_add{_relaxed,_acquire,_release,}
> atomic_sub, atomic_sub_return{_relaxed,_acquire,_release,} atomic_fetch_sub{_relaxed,_acquire,_release,}
>
> atomic_and, atomic_fetch_and{_relaxed,_acquire,_release,}
> atomic_or, atomic_fetch_or{_relaxed,_acquire,_release,}
> atomic_xor, atomic_fetch_xor{_relaxed,_acquire,_release,}
>

Another approach would be to override __atomic_op_{acquire,release} and
use things like:

"FENCE r,rw" -- (load) ACQUIRE
"FENCE rw,w" -- (store) RELEASE

And then you only need to provide _relaxed atomics.

Also, and I didn't check for that, you need to provide:

smp_load_acquire(), smp_store_release(), atomic_read_acquire(),
atomic_store_release().