Re: [PATCH RFC cmpxchg 2/8] sparc: Emulate one-byte and two-byte cmpxchg

[Paul E. McKenney]

On Tue, Apr 02, 2024 at 05:11:38AM +0100, Al Viro wrote:
> On Tue, Apr 02, 2024 at 04:37:53AM +0100, Al Viro wrote:
> > On Tue, Apr 02, 2024 at 01:07:58AM +0100, Al Viro wrote:
> > 
> > > It does, IIRC.
> > > 
> > > > Would you like to do that patch?  If so, I would be happy to drop mine
> > > > in favor of yours.  If not, could I please have your Signed-off-by so
> > > > I can do the Co-developed-by dance?
> > > 
> > > Will do once I dig my way from under the pile of mail (sick for a week
> > > and subscribed to l-k, among other lists)...
> > 
> > FWIW, parisc is in the same situation - atomics-by-cached-spinlocks.
> > 've a candidate branch, will post if it survives build...
> 
> Seems to survive.  See
> git://git.kernel.org:/pub/scm/linux/kernel/git/viro/vfs.git misc.cmpxchg
> 
> Completely untested; builds on several configs, but that's it.
> Al Viro (8):
>       sparc32: make __cmpxchg_u32() return u32
>       sparc32: make the first argument of __cmpxchg_u64() volatile u64 *
>       sparc32: unify __cmpxchg_u{32,64}
>       sparc32: add __cmpxchg_u{8,16}() and teach __cmpxchg() to handle those sizes
>       parisc: __cmpxchg_u32(): lift conversion into the callers
>       parisc: unify implementations of __cmpxchg_u{8,32,64}
>       parisc: add missing export of __cmpxchg_u8()
>       parisc: add u16 support to cmpxchg()
> 
>  arch/parisc/include/asm/cmpxchg.h   | 16 ++++++------
>  arch/parisc/kernel/parisc_ksyms.c   |  2 ++
>  arch/parisc/lib/bitops.c            | 52 ++++++++++++-------------------------
>  arch/sparc/include/asm/cmpxchg_32.h | 11 +++++---
>  arch/sparc/lib/atomic32.c           | 45 ++++++++++++++------------------
>  5 files changed, 55 insertions(+), 71 deletions(-)
> 
> Individual patches in followups.

Very good, thank you!  I will take yours in place of mine on my next
rebase.

							Thanx, Paul