From owner-svn-src-head@freebsd.org Wed Feb 1 14:17:34 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5BF2BCCB8C4; Wed, 1 Feb 2017 14:17:34 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id CF45819C2; Wed, 1 Feb 2017 14:17:33 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id v11EHLgs016000 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 1 Feb 2017 16:17:21 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua v11EHLgs016000 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id v11EHL2r015999; Wed, 1 Feb 2017 16:17:21 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 1 Feb 2017 16:17:21 +0200 From: Konstantin Belousov To: Alexander Kabaev Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r313040 - head/sys/mips/include Message-ID: <20170201141721.GB2092@kib.kiev.ua> References: <201702010500.v1150YLR075051@repo.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201702010500.v1150YLR075051@repo.freebsd.org> User-Agent: Mutt/1.7.2 (2016-11-26) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 Feb 2017 14:17:34 -0000 On Wed, Feb 01, 2017 at 05:00:34AM +0000, Alexander Kabaev wrote: > Author: kan > Date: Wed Feb 1 05:00:34 2017 > New Revision: 313040 > URL: https://svnweb.freebsd.org/changeset/base/313040 > > Log: > Add atomic_fcmpset_*() inlines for MIPS > > atomic_fcmpset_*() is analogous to atomic_cmpset(), but saves off the > read value from the target memory location into the 'old' pointer. > > Reviewed by: imp, brooks > Requested by: mjg > Differential Revision: https://reviews.freebsd.org/D9391 > > Modified: > head/sys/mips/include/atomic.h > > Modified: head/sys/mips/include/atomic.h > ============================================================================== > --- head/sys/mips/include/atomic.h Wed Feb 1 04:54:23 2017 (r313039) > +++ head/sys/mips/include/atomic.h Wed Feb 1 05:00:34 2017 (r313040) > @@ -362,7 +362,7 @@ atomic_load_64(__volatile uint64_t *p, u > * zero if the compare failed, nonzero otherwise. > */ > static __inline uint32_t > -atomic_cmpset_32(__volatile uint32_t* p, uint32_t cmpval, uint32_t newval) > +atomic_cmpset_32(__volatile uint32_t *p, uint32_t cmpval, uint32_t newval) > { > uint32_t ret; > > @@ -405,6 +405,46 @@ atomic_cmpset_rel_32(__volatile uint32_t > return (atomic_cmpset_32(p, cmpval, newval)); > } > > +static __inline uint32_t > +atomic_fcmpset_32(__volatile uint32_t *p, uint32_t *cmpval, uint32_t newval) > +{ > + uint32_t ret; > + > + __asm __volatile ( > + "1:\n\t" > + "ll %0, %1\n\t" /* load old value */ > + "bne %0, %4, 2f\n\t" /* compare */ > + "move %0, %3\n\t" /* value to store */ > + "sc %0, %1\n\t" /* attempt to store */ > + "beqz %0, 1b\n\t" /* if it failed, spin */ Please do not retry on sc failure, return the error to upper layer. See also r313007 and preceeding discussion after r312973. > + "j 3f\n\t" > + "2:\n\t" > + "sw %0, %2\n\t" /* save old value */ > + "li %0, 0\n\t" > + "3:\n" > + : "=&r" (ret), "+m" (*p), "=m" (*cmpval) > + : "r" (newval), "r" (*cmpval) > + : "memory"); > + return ret; > +} > +