Received-SPF: pass (google.com: domain of linux-kernel+bounces-127365-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Date: Mon, 1 Apr 2024 21:18:42 -0700
From: "Paul E. McKenney" <paulmck@kernel.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com,
	"David S. Miller" <davem@davemloft.net>,
	Andreas Larsson <andreas@gaisler.com>,
	Palmer Dabbelt <palmer@rivosinc.com>, Arnd Bergmann <arnd@arndb.de>,
	Marco Elver <elver@google.com>
Subject: Re: [PATCH RFC cmpxchg 2/8] sparc: Emulate one-byte and two-byte
 cmpxchg
Message-ID: <c6581992-03c6-44e4-8d98-0a73a5ea948b@paulmck-laptop>
Reply-To: paulmck@kernel.org
References: <31c82dcc-e203-48a9-aadd-f2fcd57d94c1@paulmck-laptop>
 <20240401213950.3910531-2-paulmck@kernel.org>
 <20240401223803.GZ538574@ZenIV>
 <114dc62e-e0fb-41c8-bf9c-a9fda8b19eb6@paulmck-laptop>
 <20240402000758.GC538574@ZenIV>
 <20240402033753.GE538574@ZenIV>
 <20240402041138.GF538574@ZenIV>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240402041138.GF538574@ZenIV>

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