From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3C8BC433B4 for ; Mon, 12 Apr 2021 22:11:01 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 60046600D4 for ; Mon, 12 Apr 2021 22:11:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 60046600D4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FK2xb75KCz3bxy for ; Tue, 13 Apr 2021 08:10:59 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=permerror (SPF Permanent Error: Unknown mechanism found: ip:192.40.192.88/32) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 4FK2xD2SRbz2yy3 for ; Tue, 13 Apr 2021 08:10:39 +1000 (AEST) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 13CM8MKP012708; Mon, 12 Apr 2021 17:08:22 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 13CM8MWJ012707; Mon, 12 Apr 2021 17:08:22 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 12 Apr 2021 17:08:22 -0500 From: Segher Boessenkool To: Christophe Leroy Subject: Re: [PATCH v1 2/2] powerpc/atomics: Use immediate operand when possible Message-ID: <20210412220821.GN26583@gate.crashing.org> References: <09da6fec57792d6559d1ea64e00be9870b02dab4.1617896018.git.christophe.leroy@csgroup.eu> <9f50b5fadeb090553e5c2fae025052d04d52f3c7.1617896018.git.christophe.leroy@csgroup.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9f50b5fadeb090553e5c2fae025052d04d52f3c7.1617896018.git.christophe.leroy@csgroup.eu> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi! On Thu, Apr 08, 2021 at 03:33:45PM +0000, Christophe Leroy wrote: > +#define ATOMIC_OP(op, asm_op, dot, sign) \ > static __inline__ void atomic_##op(int a, atomic_t *v) \ > { \ > int t; \ > \ > __asm__ __volatile__( \ > "1: lwarx %0,0,%3 # atomic_" #op "\n" \ > - #asm_op " %0,%2,%0\n" \ > + #asm_op "%I2" dot " %0,%0,%2\n" \ > " stwcx. %0,0,%3 \n" \ > " bne- 1b\n" \ > - : "=&r" (t), "+m" (v->counter) \ > - : "r" (a), "r" (&v->counter) \ > + : "=&b" (t), "+m" (v->counter) \ > + : "r"#sign (a), "r" (&v->counter) \ > : "cc"); \ > } \ You need "b" (instead of "r") only for "addi". You can use "addic" instead, which clobbers XER[CA], but *all* inline asm does, so that is not a downside here (it is also not slower on any CPU that matters). > @@ -238,14 +238,14 @@ static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u) > "1: lwarx %0,0,%1 # atomic_fetch_add_unless\n\ > cmpw 0,%0,%3 \n\ > beq 2f \n\ > - add %0,%2,%0 \n" > + add%I2 %0,%0,%2 \n" > " stwcx. %0,0,%1 \n\ > bne- 1b \n" > PPC_ATOMIC_EXIT_BARRIER > -" subf %0,%2,%0 \n\ > +" sub%I2 %0,%0,%2 \n\ > 2:" > - : "=&r" (t) > - : "r" (&v->counter), "r" (a), "r" (u) > + : "=&b" (t) > + : "r" (&v->counter), "rI" (a), "r" (u) > : "cc", "memory"); Same here. Nice patches! Acked-by: Segher Boessenkool Segher From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45802C433B4 for ; Mon, 12 Apr 2021 22:14:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 191586128E for ; Mon, 12 Apr 2021 22:14:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343645AbhDLWOW (ORCPT ); Mon, 12 Apr 2021 18:14:22 -0400 Received: from gate.crashing.org ([63.228.1.57]:60708 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243890AbhDLWOG (ORCPT ); Mon, 12 Apr 2021 18:14:06 -0400 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 13CM8MKP012708; Mon, 12 Apr 2021 17:08:22 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 13CM8MWJ012707; Mon, 12 Apr 2021 17:08:22 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 12 Apr 2021 17:08:22 -0500 From: Segher Boessenkool To: Christophe Leroy Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 2/2] powerpc/atomics: Use immediate operand when possible Message-ID: <20210412220821.GN26583@gate.crashing.org> References: <09da6fec57792d6559d1ea64e00be9870b02dab4.1617896018.git.christophe.leroy@csgroup.eu> <9f50b5fadeb090553e5c2fae025052d04d52f3c7.1617896018.git.christophe.leroy@csgroup.eu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9f50b5fadeb090553e5c2fae025052d04d52f3c7.1617896018.git.christophe.leroy@csgroup.eu> User-Agent: Mutt/1.4.2.3i Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! On Thu, Apr 08, 2021 at 03:33:45PM +0000, Christophe Leroy wrote: > +#define ATOMIC_OP(op, asm_op, dot, sign) \ > static __inline__ void atomic_##op(int a, atomic_t *v) \ > { \ > int t; \ > \ > __asm__ __volatile__( \ > "1: lwarx %0,0,%3 # atomic_" #op "\n" \ > - #asm_op " %0,%2,%0\n" \ > + #asm_op "%I2" dot " %0,%0,%2\n" \ > " stwcx. %0,0,%3 \n" \ > " bne- 1b\n" \ > - : "=&r" (t), "+m" (v->counter) \ > - : "r" (a), "r" (&v->counter) \ > + : "=&b" (t), "+m" (v->counter) \ > + : "r"#sign (a), "r" (&v->counter) \ > : "cc"); \ > } \ You need "b" (instead of "r") only for "addi". You can use "addic" instead, which clobbers XER[CA], but *all* inline asm does, so that is not a downside here (it is also not slower on any CPU that matters). > @@ -238,14 +238,14 @@ static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u) > "1: lwarx %0,0,%1 # atomic_fetch_add_unless\n\ > cmpw 0,%0,%3 \n\ > beq 2f \n\ > - add %0,%2,%0 \n" > + add%I2 %0,%0,%2 \n" > " stwcx. %0,0,%1 \n\ > bne- 1b \n" > PPC_ATOMIC_EXIT_BARRIER > -" subf %0,%2,%0 \n\ > +" sub%I2 %0,%0,%2 \n\ > 2:" > - : "=&r" (t) > - : "r" (&v->counter), "r" (a), "r" (u) > + : "=&b" (t) > + : "r" (&v->counter), "rI" (a), "r" (u) > : "cc", "memory"); Same here. Nice patches! Acked-by: Segher Boessenkool Segher