From patchwork Mon Jun 10 19:32:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 166370 Delivered-To: patch@linaro.org Received: by 2002:a92:4782:0:0:0:0:0 with SMTP id e2csp1410391ilk; Mon, 10 Jun 2019 12:33:57 -0700 (PDT) X-Google-Smtp-Source: APXvYqxOR4+C9zFgk3w3IXyY6OGHPOv4KhrZIKG0qtSi8E0ide67jy6rI9h1EN5RGTCwTT4WJqw1 X-Received: by 2002:a02:5801:: with SMTP id f1mr47241005jab.40.1560195237163; Mon, 10 Jun 2019 12:33:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1560195237; cv=none; d=google.com; s=arc-20160816; b=IOWQcOtqmnbFNo4xgoMu8LDYjP7uqUTn3iTLe0upoNXaaytvRlV4VQxNJKBsL7oBqK bRKcG9rjDohL9kMSbMs/j4z9uW9RbV+mCtvPVXa+ZItgwJeu01a9fof/rcS98yUwhQlg LmoyVEMNQD/Sy9+VMJNFPaHLaurnhdmRxozvExsBoJL7hfp3aDVCE7tMVz+wSjJ/kfnY IlrRF2QSrq97V5nxQUyHeyHh5RhSHr2ag/etIpjMeV5zPKzrSNj8t17xMa6+alF4hOsn VIIRVHxhyZYhFoCYeGg9gqrl9kSvZiTh0R4G4i5JFKcq6YH7HdwbOSmvk+5mSFJkj0YV 1f0g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:mime-version:cc :list-subscribe:list-help:list-post:list-unsubscribe:list-id :precedence:subject:references:in-reply-to:message-id:date:to:from; bh=5MxHbm99ugLBZbK08cA+blZ8kYFB1QQxE/bTY2ge4TY=; b=waZOGYB4yEHDgEyqjKFXivSMvucZTGdmV0OPwhptT9xJVOx6sx9Xo2SemS8lPKw4d/ R3M0dexPx8Zj1o0EICYDhw5LZc0obcbTo9ORt/CleIdedX9xD3WPELk1zgCXv2Ra/ri8 npQFeJ4AjvZwKYgGblWPXUn+kF+JXjRh7gyOhF6YziM4SCpnfjhXnGeK+grIT+qYBHxp cwdkBltLFAXUsNTAtTf2Y2/z6xI8RtCDJckOhaZd4K/Kh9cZ5q2J1jkgkoFwzRHOa8vx 7ISefYpl5BGqkOWZ+I0z8rJgF/haAv6ROotWZWOR/Lzdz652P9w/wyyHoAlst2c3J4Wo /C4Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org. [192.237.175.120]) by mx.google.com with ESMTPS id l187si170792itg.139.2019.06.10.12.33.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 10 Jun 2019 12:33:57 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1haQ1w-0007h4-Hc; Mon, 10 Jun 2019 19:32:32 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1haQ1u-0007ez-SM for xen-devel@lists.xenproject.org; Mon, 10 Jun 2019 19:32:30 +0000 X-Inumbo-ID: 7ca62288-8bb6-11e9-8980-bc764e045a96 Received: from foss.arm.com (unknown [217.140.110.172]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTP id 7ca62288-8bb6-11e9-8980-bc764e045a96; Mon, 10 Jun 2019 19:32:30 +0000 (UTC) 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 2A096C0A; Mon, 10 Jun 2019 12:32:30 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 420733F73C; Mon, 10 Jun 2019 12:32:29 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Mon, 10 Jun 2019 20:32:07 +0100 Message-Id: <20190610193215.23704-10-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190610193215.23704-1-julien.grall@arm.com> References: <20190610193215.23704-1-julien.grall@arm.com> Subject: [Xen-devel] [PATCH 09/17] xen/arm64: head: Improve coding style and document cpu_init() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: andre.przywara@arm.com, Julien Grall , Stefano Stabellini , andrii_anisov@epam.com, Oleksandr_Tyshchenko@epam.com MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Adjust the coding style used in the comments within cpu_init(). Take the opportunity to alter the early print to match the function name. Lastly, document the behavior and the main registers usage within the function. Signed-off-by: Julien Grall --- xen/arch/arm/arm64/head.S | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S index 6aa3148192..ee0024173e 100644 --- a/xen/arch/arm/arm64/head.S +++ b/xen/arch/arm/arm64/head.S @@ -396,19 +396,26 @@ skip_bss: ret ENDPROC(zero_bss) +/* + * Initialize the processor for turning the MMU on. + * + * Clobbers x0 - x4 + */ cpu_init: - PRINT("- Setting up control registers -\r\n") + PRINT("- Initialize CPU -\r\n") /* Set up memory attribute type tables */ ldr x0, =MAIRVAL msr mair_el2, x0 - /* Set up TCR_EL2: + /* + * Set up TCR_EL2: * PS -- Based on ID_AA64MMFR0_EL1.PARange * Top byte is used * PT walks use Inner-Shareable accesses, * PT walks are write-back, write-allocate in both cache levels, - * 48-bit virtual address space goes through this table. */ + * 48-bit virtual address space goes through this table. + */ ldr x0, =(TCR_RES1|TCR_SH0_IS|TCR_ORGN0_WBWA|TCR_IRGN0_WBWA|TCR_T0SZ(64-48)) /* ID_AA64MMFR0_EL1[3:0] (PARange) corresponds to TCR_EL2[18:16] (PS) */ mrs x1, ID_AA64MMFR0_EL1 @@ -427,9 +434,11 @@ cpu_init: ldr x0, =(HSCTLR_BASE) msr SCTLR_EL2, x0 - /* Ensure that any exceptions encountered at EL2 + /* + * Ensure that any exceptions encountered at EL2 * are handled using the EL2 stack pointer, rather - * than SP_EL0. */ + * than SP_EL0. + */ msr spsel, #1 ret ENDPROC(cpu_init)