From patchwork Wed Feb 26 18:05:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 11406903 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7F19C14B4 for ; Wed, 26 Feb 2020 18:05:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 36A342465D for ; Wed, 26 Feb 2020 18:05:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="e9rR6S2I" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36A342465D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OaW6KPRjjwm+tpjNkEfArRKnhaCT8UQd4wDqv823XWo=; b=e9rR6S2II63wXA UaAdy8TP2ZdBqa+Jgu7sNj4cJekqXZnYrlRPI8hQ25OHsFXm96m9Zr6iH+jau4eGGMJ3CCQ34RvnA a768XcM1GHsKGH+bhMMEl8hTQxpquEqlpJxvSElIaKxh+3cvofVy7v5M0G4/ocQaEaaDK667WvAci M9zz8WFDweo/JetEh6WmFhq6EQLq8hjqhTOInHKzW8/AjQc+15PzH6h7IXWuYqyIuc/QiXXMp32tz SiEj7CkoB9qt6PTM+8QHSAnA3RaiHgy6w3LZXOqKoLwdx/wlrZgNZtc122zHPilsBcmkQEYir1s5Y 0zVlTT4sKxRzpLt6lG9g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j714C-0007Qd-FK; Wed, 26 Feb 2020 18:05:52 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j713z-0007Es-Ks for linux-arm-kernel@lists.infradead.org; Wed, 26 Feb 2020 18:05:42 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C290031B; Wed, 26 Feb 2020 10:05:37 -0800 (PST) Received: from arrakis.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 596F53F881; Wed, 26 Feb 2020 10:05:36 -0800 (PST) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 01/19] arm64: alternative: Allow alternative_insn to always issue the first instruction Date: Wed, 26 Feb 2020 18:05:08 +0000 Message-Id: <20200226180526.3272848-2-catalin.marinas@arm.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200226180526.3272848-1-catalin.marinas@arm.com> References: <20200226180526.3272848-1-catalin.marinas@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200226_100539_735244_AEA9EA38 X-CRM114-Status: GOOD ( 10.29 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Richard Earnshaw , Szabolcs Nagy , Andrey Konovalov , Kevin Brodsky , Peter Collingbourne , linux-mm@kvack.org, Vincenzo Frascino , Will Deacon Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org There are situations where we do not want to disable the whole block based on a config option, only the alternative part while keeping the first instruction. Improve the alternative_insn assembler macro to take a 'first_insn' argument, default 0 to preserve the current behaviour. Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/alternative.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h index 324e7d5ab37e..44083424d7aa 100644 --- a/arch/arm64/include/asm/alternative.h +++ b/arch/arm64/include/asm/alternative.h @@ -111,7 +111,11 @@ static inline void apply_alternatives_module(void *start, size_t length) { } .byte \alt_len .endm -.macro alternative_insn insn1, insn2, cap, enable = 1 +/* + * Disable the whole block if enable == 0, unless first_insn == 1 in which + * case insn1 will always be issued but without an alternative insn2. + */ +.macro alternative_insn insn1, insn2, cap, enable = 1, first_insn = 0 .if \enable 661: \insn1 662: .pushsection .altinstructions, "a" @@ -122,6 +126,8 @@ static inline void apply_alternatives_module(void *start, size_t length) { } 664: .popsection .org . - (664b-663b) + (662b-661b) .org . - (662b-661b) + (664b-663b) + .elseif \first_insn + \insn1 .endif .endm