Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752497AbdGBD4b (ORCPT ); Sat, 1 Jul 2017 23:56:31 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:35604 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697AbdGBD43 (ORCPT ); Sat, 1 Jul 2017 23:56:29 -0400 Date: Sun, 2 Jul 2017 11:58:07 +0800 From: Boqun Feng To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, parri.andrea@gmail.com, dave@stgolabs.net, manfred@colorfullife.com, arnd@arndb.de, peterz@infradead.org, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, will.deacon@arm.com, oleg@redhat.com, mingo@redhat.com, netfilter-devel@vger.kernel.org, tj@kernel.org, stern@rowland.harvard.edu, akpm@linux-foundation.org, torvalds@linux-foundation.org, Paul Mackerras Subject: Re: [PATCH RFC 21/26] powerpc: Remove spin_unlock_wait() arch-specific definitions Message-ID: <20170702035807.tnzmkynyevfobt5a@tardis> References: <20170629235918.GA6445@linux.vnet.ibm.com> <1498780894-8253-21-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="7nfvfvnv5t6syok4" Content-Disposition: inline In-Reply-To: <1498780894-8253-21-git-send-email-paulmck@linux.vnet.ibm.com> User-Agent: NeoMutt/20170225 (1.8.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2868 Lines: 99 --7nfvfvnv5t6syok4 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 29, 2017 at 05:01:29PM -0700, Paul E. McKenney wrote: > There is no agreed-upon definition of spin_unlock_wait()'s semantics, > and it appears that all callers could do just as well with a lock/unlock > pair. This commit therefore removes the underlying arch-specific > arch_spin_unlock_wait(). >=20 > Signed-off-by: Paul E. McKenney > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Michael Ellerman > Cc: > Cc: Will Deacon > Cc: Peter Zijlstra > Cc: Alan Stern > Cc: Andrea Parri > Cc: Linus Torvalds Acked-by: Boqun Feng Regards, Boqun > --- > arch/powerpc/include/asm/spinlock.h | 33 -------------------------------= -- > 1 file changed, 33 deletions(-) >=20 > diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/a= sm/spinlock.h > index 8c1b913de6d7..d256e448ea49 100644 > --- a/arch/powerpc/include/asm/spinlock.h > +++ b/arch/powerpc/include/asm/spinlock.h > @@ -170,39 +170,6 @@ static inline void arch_spin_unlock(arch_spinlock_t = *lock) > lock->slock =3D 0; > } > =20 > -static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) > -{ > - arch_spinlock_t lock_val; > - > - smp_mb(); > - > - /* > - * Atomically load and store back the lock value (unchanged). This > - * ensures that our observation of the lock value is ordered with > - * respect to other lock operations. > - */ > - __asm__ __volatile__( > -"1: " PPC_LWARX(%0, 0, %2, 0) "\n" > -" stwcx. %0, 0, %2\n" > -" bne- 1b\n" > - : "=3D&r" (lock_val), "+m" (*lock) > - : "r" (lock) > - : "cr0", "xer"); > - > - if (arch_spin_value_unlocked(lock_val)) > - goto out; > - > - while (lock->slock) { > - HMT_low(); > - if (SHARED_PROCESSOR) > - __spin_yield(lock); > - } > - HMT_medium(); > - > -out: > - smp_mb(); > -} > - > /* > * Read-write spinlocks, allowing multiple readers > * but only one writer. > --=20 > 2.5.2 >=20 --7nfvfvnv5t6syok4 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEj5IosQTPz8XU1wRHSXnow7UH+rgFAllYbx4ACgkQSXnow7UH +rjJoAf9ER3wqVQgGOVwgLauCT8gfxl5xT9ZzXPdSZ8ZpBbbiS3hMKitAc/pBO8c HC/NF4DhvxyX7oogUcYIQgRGrvF1NbPpl5QwDsCmlaWSj7V/nU3R9TzOtjB0ToDq L8s0/R6PLQHixtjpgT06/X5xF2xPHoTdD8WzfBm03chtxAKhLvuWRhS/yU46Q9aE r0TMMq2oFtTiwH9SzL6avxd1h7hHqjAQUTLiJkncmGJpXS5bLUyxAQNw7zpWz252 yYrdC6JDqVLTrjPoeUwZIUy1WqOzvIK9/Y/7RAOYTSSYi5FWqbRIcHPmI90EzQ0r fyAoYkKvRleSV1Lzv14RP7DLZse/tA== =u8hv -----END PGP SIGNATURE----- --7nfvfvnv5t6syok4--