From patchwork Mon Jun 10 19:32:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 166374 Delivered-To: patch@linaro.org Received: by 2002:a92:4782:0:0:0:0:0 with SMTP id e2csp1410358ilk; Mon, 10 Jun 2019 12:33:54 -0700 (PDT) X-Google-Smtp-Source: APXvYqy/feL1C/V/UYSbQCy2BZSjp4q1ILoZz/daVGocmEEpiXekAY1yBIHuqPUaB3zUvTd3AETZ X-Received: by 2002:a24:b543:: with SMTP id j3mr14760238iti.23.1560195234465; Mon, 10 Jun 2019 12:33:54 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1560195234; cv=none; d=google.com; s=arc-20160816; b=kURq+ohseiDqWR/Y8WjWXQjIhoKWIU5eCaWHabc1frKZMg7YdhhvCzI7jbwxYVTHAa KfYKQIQsSUyGJzxjgxJPeekR+9TDq4r5cCxLxtlFO8fr9DDhSgp8DBzrBX4RuhGrJOWp VShmI+Ud8D27MxP3k2qeoq2YSWmAhM0GGFphP5sF5CAWknd+Vs+hyI6VuWZlG0BMutjw 2yQ0gfEpYIskddkl2BVSD/VVFaK99f20gXiqqEIoDyVzCpWhlrad0HLtAs49zMG6JjP/ JMg6gTF+o/NS6RUyy69PILAAUDYaZHqtq/Qe612DbIpnBMy12nbMfixoy08BHuyqtc37 6wYQ== 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=7ECuch8Odd3W4FaWwUogDq7dtZ0Ec/IG1hrBaMOZg/Y=; b=vakFYL5LPfW6CiEif3ZToGOkkLpvXIJvBvv6Wu8IImiWSzfz7I05EGNzJiwA8kw08f 6G21MeIPYcXazipfpkkJS7oGk/VCQeGQsqo/i2FZgX4qDr5q5oMHbtMphjPLuWHqZHa7 WOqMXx57EXzrcauHUhViJzFhRPkDcENzBtC2w7dW0rdVVHnkj4xnUfzWPNN+LHSfrBhN MFOWKVp4fOjV1B/28XGBQACGTP6WkSNLZbOZnu5Q94QzrvbaRy5Uyln5T/1HIWLo96UX DARekGyatT7gyYU2Un87cKju+GR7uPp4zS7AfzGui9egygNB2/fvLtanAPeroYDfwk3U dZog== 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 k2si7471999jac.121.2019.06.10.12.33.54 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 10 Jun 2019 12:33:54 -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 1haQ23-0007oP-50; Mon, 10 Jun 2019 19:32:39 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1haQ21-0007mR-FR for xen-devel@lists.xenproject.org; Mon, 10 Jun 2019 19:32:37 +0000 X-Inumbo-ID: 8096a8d5-8bb6-11e9-8980-bc764e045a96 Received: from foss.arm.com (unknown [217.140.110.172]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTP id 8096a8d5-8bb6-11e9-8980-bc764e045a96; Mon, 10 Jun 2019 19:32:36 +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 D316AC0A; Mon, 10 Jun 2019 12:32:36 -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 EB3913F73C; Mon, 10 Jun 2019 12:32:35 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Mon, 10 Jun 2019 20:32:13 +0100 Message-Id: <20190610193215.23704-16-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 15/17] xen/arm64: head: Rework and document setup_fixmap() 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" At the moment, the fixmap table is only hooked when earlyprintk is used. This is fine today because in C land, the fixmap is not used by anyone until the the boot CPU is switching to the runtime page-tables. In the future, the boot CPU will not switch between page-tables to avoid TLB conflict. This means the fixmap table will need to be hooked before any use. For simplicity, setup_fixmap() will now do that job. Lastly, document the behavior and the main registers usage within the function. Signed-off-by: Julien Grall Acked-by: Stefano Stabellini --- xen/arch/arm/arm64/head.S | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S index 96e85f8834..4f7fa6769f 100644 --- a/xen/arch/arm/arm64/head.S +++ b/xen/arch/arm/arm64/head.S @@ -700,8 +700,17 @@ id_map_removed: ret ENDPROC(remove_id_map) +/* + * Map the UART in the fixmap (when earlyprintk is used) and hook the + * fixmap table in the page tables. + * + * The fixmap cannot be mapped in create_page_tables because it may + * clash with the ID map. + * + * Clobbers x0 - x1 + */ setup_fixmap: -#if defined(CONFIG_EARLY_PRINTK) /* Fixmap is only used by early printk */ +#ifdef CONFIG_EARLY_PRINTK /* Add UART to the fixmap table */ ldr x1, =xen_fixmap /* x1 := vaddr (xen_fixmap) */ lsr x2, x23, #THIRD_SHIFT @@ -709,6 +718,7 @@ setup_fixmap: mov x3, #PT_DEV_L3 orr x2, x2, x3 /* x2 := 4K dev map including UART */ str x2, [x1, #(FIXMAP_CONSOLE*8)] /* Map it in the first fixmap's slot */ +#endif /* Map fixmap into boot_second */ ldr x4, =boot_second /* x4 := vaddr (boot_second) */ @@ -721,7 +731,6 @@ setup_fixmap: /* Ensure any page table updates made above have occurred */ dsb nshst -#endif ret ENDPROC(setup_fixmap)