From patchwork Tue Mar 2 09:01:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 12112573 X-Patchwork-Delegate: herbert@gondor.apana.org.au 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 2A8C0C433E0 for ; Wed, 3 Mar 2021 01:31:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA48C64E28 for ; Wed, 3 Mar 2021 01:31:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235255AbhCCB11 (ORCPT ); Tue, 2 Mar 2021 20:27:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:38806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378841AbhCBJCz (ORCPT ); Tue, 2 Mar 2021 04:02:55 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E2FFF64F17; Tue, 2 Mar 2021 09:02:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614675727; bh=2dT6mS2FFzladJNHwGXpprvyDFYQ/2V8jtWs5f4jiaU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hhM2Ee6sYkTSCapuxbPzIjkGhESYtS5C/hARH/qMLkj5Uc9MzgzsBEnFExA8gA7qL NBqmr2a/08IPUke5S954S5b0jfoBcUtVzplbVQa86O4fifwsRMjh544cfin8IcDjZw q89BiAGy8uxuuBNIqbh8YIIz4N7sv53u2JAwgHV6RkmMMpzw661Ext7Iu4wVYm+Nhz pbztFkPDBT9P6hViEui+nSljTW1BF6ryE6sy0Dha68B/pM2BO607SN1T0Dy+1jYZzK +t2XKCH6CxTjmSJVqt6W1SjcnpvF/uKNxIiK50SyoJSeF837UN91dWrwKrLwTXq4Jk 7JUIW8Wcu5tTw== From: Ard Biesheuvel To: linux-crypto@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Dave Martin , Mark Brown , Herbert Xu , Eric Biggers , Will Deacon , Catalin Marinas , Thomas Gleixner , Peter Zijlstra , Sebastian Andrzej Siewior , Ingo Molnar , Andy Lutomirski Subject: [PATCH v2 2/9] arm64: assembler: introduce wxN aliases for wN registers Date: Tue, 2 Mar 2021 10:01:11 +0100 Message-Id: <20210302090118.30666-3-ardb@kernel.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210302090118.30666-1-ardb@kernel.org> References: <20210302090118.30666-1-ardb@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org The AArch64 asm syntax has this slightly tedious property that the names used in mnemonics to refer to registers depend on whether the opcode in question targets the entire 64-bits (xN), or only the least significant 8, 16 or 32 bits (wN). When writing parameterized code such as macros, this can be annoying, as macro arguments don't lend themselves to indexed lookups, and so generating a reference to wN in a macro that receives xN as an argument is problematic. For instance, an upcoming patch that modifies the implementation of the cond_yield macro to be able to refer to 32-bit registers would need to modify invocations such as cond_yield 3f, x8 to cond_yield 3f, 8 so that the second argument can be token pasted after x or w to emit the correct register reference. Unfortunately, this interferes with the self documenting nature of the first example, where the second argument is obviously a register, whereas in the second example, one would need to go and look at the code to find out what '8' means. So let's fix this by defining wxN aliases for all xN registers, which resolve to the 32-bit alias of each respective 64-bit register. This allows the macro implementation to paste the xN reference after a w to obtain the correct register name. Signed-off-by: Ard Biesheuvel Acked-by: Will Deacon --- arch/arm64/include/asm/assembler.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index e0fc1d424f9b..7b076ccd1a54 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -23,6 +23,14 @@ #include #include + /* + * Provide a wxN alias for each wN register so what we can paste a xN + * reference after a 'w' to obtain the 32-bit version. + */ + .irp n,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30 + wx\n .req w\n + .endr + .macro save_and_disable_daif, flags mrs \flags, daif msr daifset, #0xf