From patchwork Thu Sep 8 12:55:34 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 75785 Delivered-To: patch@linaro.org Received: by 10.140.106.11 with SMTP id d11csp829777qgf; Thu, 8 Sep 2016 05:58:10 -0700 (PDT) X-Received: by 10.98.138.201 with SMTP id o70mr5772958pfk.55.1473339488972; Thu, 08 Sep 2016 05:58:08 -0700 (PDT) Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id pa7si47003054pac.177.2016.09.08.05.58.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 08 Sep 2016 05:58:08 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bhysy-0003Dh-TM; Thu, 08 Sep 2016 12:56:56 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bhysM-0002kv-Lx for linux-arm-kernel@lists.infradead.org; Thu, 08 Sep 2016 12:56:21 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AAFBCCE3; Thu, 8 Sep 2016 05:56:00 -0700 (PDT) Received: from leverpostej.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 645663F2E5; Thu, 8 Sep 2016 05:55:59 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/6] arm64: sysreg: allow write_sysreg to use XZR Date: Thu, 8 Sep 2016 13:55:34 +0100 Message-Id: <1473339339-32334-2-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1473339339-32334-1-git-send-email-mark.rutland@arm.com> References: <1473339339-32334-1-git-send-email-mark.rutland@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160908_055618_879916_99D9955A X-CRM114-Status: UNSURE ( 8.57 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -8.3 (--------) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-8.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.101.70 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, suzuki.poulose@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, robin.murphy@arm.com, christoffer.dall@linaro.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org Currently write_sysreg has to allocate a temporary register to write zero to a system register, which is unfortunate given that the MSR instruction accepts XZR as an operand. Allow XZR to be used when appropriate by fiddling with the assembly constraints. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Marc Zyngier Cc: Robin Murphy Cc: Suzuki K Poulose Cc: Will Deacon --- arch/arm64/include/asm/sysreg.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index cc06794..39fed2e 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -273,10 +273,14 @@ static inline void config_sctlr_el1(u32 clear, u32 set) __val; \ }) +/* + * The "Z" constraint normally means a zero immediate, but when combined with + * the "%x0" template means XZR. + */ #define write_sysreg(v, r) do { \ u64 __val = (u64)v; \ - asm volatile("msr " __stringify(r) ", %0" \ - : : "r" (__val)); \ + asm volatile("msr " __stringify(r) ", %x0" \ + : : "rZ" (__val)); \ } while (0) #endif