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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 B8544C3A5A3 for ; Tue, 27 Aug 2019 18:28:28 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 462DF2070B for ; Tue, 27 Aug 2019 18:28:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 462DF2070B 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 bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46Hy6x5ngczDqsp for ; Wed, 28 Aug 2019 04:28:25 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=permerror (mailfrom) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46Hy4m2gPyzDqWn for ; Wed, 28 Aug 2019 04:26:32 +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 x7RIQHbP000982; Tue, 27 Aug 2019 13:26:17 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x7RIQGDG000979; Tue, 27 Aug 2019 13:26:16 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Tue, 27 Aug 2019 13:26:16 -0500 From: Segher Boessenkool To: Christophe Leroy Subject: Re: [PATCH 2/2] powerpc: cleanup hw_irq.h Message-ID: <20190827182616.GB31406@gate.crashing.org> References: <0f7e164afb5d1b022441559fe5a999bb6d3c0a23.1566893505.git.christophe.leroy@c-s.fr> <81f39fa06ae582f4a783d26abd2b310204eba8f4.1566893505.git.christophe.leroy@c-s.fr> <1566909844.x4jee1jjda.astroid@bobo.none> <20190827172909.GA31406@gate.crashing.org> <1410046b-e1a3-b892-2add-6c1d353cb781@c-s.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1410046b-e1a3-b892-2add-6c1d353cb781@c-s.fr> 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: linux-kernel@vger.kernel.org, Nicholas Piggin , Paul Mackerras , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Aug 27, 2019 at 07:36:35PM +0200, Christophe Leroy wrote: > Le 27/08/2019 à 19:29, Segher Boessenkool a écrit : > >On Tue, Aug 27, 2019 at 10:48:24PM +1000, Nicholas Piggin wrote: > >>Christophe Leroy's on August 27, 2019 6:13 pm: > >>>+#define wrtee(val) asm volatile("wrtee %0" : : "r" (val) : "memory") > >>>+#define wrteei(val) asm volatile("wrteei %0" : : "i" (val) : > >>>"memory") > >> > >>Can you implement just one macro that uses __builtin_constant_p to > >>select between the imm and reg versions? I forgot if there's some > >>corner cases that prevent that working with inline asm i constraints. > > > >static inline void wrtee(long val) > >{ > > asm volatile("wrtee%I0 %0" : : "n"(val) : "memory"); > >} > > Great, didn't know that possibility. > > Can it be used with any insn, for instance with add/addi ? > Or with mr/li ? Any instruction, yes. %I simply outputs an "i" if operand n is a constant integer, and nothing otherwise. So asm("add%I2 %0,%1,%2" : "=r"(dst) : "r"(src1), "ri"(src1)); works well. I don't see how you would use it for li/mr... You can do asm("add%I1 %0,0,%1" : "=r"(dst) : "ri"(src)); I suppose, but that is not really an mr. > >(This output modifier goes back to the dark ages, some 2.4 or something). > > Hope Clang support it ... I don't know, sorry. But it is used all over the place, see sfp-machine.h for example, so maybe? Segher