From patchwork Wed Mar 11 16:00:18 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 449195 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id A5A2F14012F for ; Thu, 12 Mar 2015 08:01:59 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 790351A125A for ; Thu, 12 Mar 2015 08:01:59 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mail-we0-f178.google.com (mail-we0-f178.google.com [74.125.82.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 5CCA11A0A16 for ; Thu, 12 Mar 2015 03:00:40 +1100 (AEDT) Received: by wesw62 with SMTP id w62so10259273wes.8 for ; Wed, 11 Mar 2015 09:00:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=/e3Myht6dP+kX8XczfyIYOiVTawiHcpRQNNailgnjOk=; b=ly8C4gbiOtE9PS6jt5xy14OLEIHx3JZbYZ46LlQIaI09z6Z2KacAcjL0b0Q35B4blV vQPmqpNBjbz+ylkQVwUCsjncjEDa4Covf3x0aX0ePIUpLPig7wh5R1Pyvu/Q93Z9Jo50 wMBMs1xSHvszP+/Nmohbb/qaLt/BB2jp4E1B8QBLcaysbqjHlsLXLAtYZXGWoGpnh4hI 4RT3iZ++8muApm2bWx1QZJ2F22HJcgg1x8M35RCaA7lYzhlncu6r+Xd5uRNr6GC2ZpmQ qowPuoJfrTRSm+8aT37ADK81dJl1iUrLyD0BUJPHgVZboLm5yrGTn0tdFGY9qVYgxY3G 2FOw== X-Gm-Message-State: ALoCoQl33ZWLuwA5251aNh1LxG70c2zgOHkFfDNiH/xUhK69Luqw/Co3tk3cVJOf50uKGP1J+qvG X-Received: by 10.180.77.110 with SMTP id r14mr58947266wiw.89.1426089636309; Wed, 11 Mar 2015 09:00:36 -0700 (PDT) Received: from ards-macbook-pro.local ([213.143.60.209]) by mx.google.com with ESMTPSA id l6sm5990041wjx.33.2015.03.11.09.00.33 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 11 Mar 2015 09:00:35 -0700 (PDT) From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org, robh@kernel.org, mark.rutland@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux@arm.linux.org.uk, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org Subject: [PATCH v2 3/5] arm64: Documentation: clarify Image placement in physical RAM Date: Wed, 11 Mar 2015 17:00:18 +0100 Message-Id: <1426089620-9459-4-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1426089620-9459-1-git-send-email-ard.biesheuvel@linaro.org> References: <1426089620-9459-1-git-send-email-ard.biesheuvel@linaro.org> X-Mailman-Approved-At: Thu, 12 Mar 2015 07:56:25 +1100 Cc: Ard Biesheuvel X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The early init code maps the kernel image using statically allocated page tables. This means that we can only allow Image to be placed such that we can map its entire static footprint using a single table entry at all but the lowest level. So update the documentation to reflect that the Image should not cross a 512 MB boundary, which ensures the above on both 4k and 64k pages kernels. Reviewed-by: Mark Rutland Signed-off-by: Ard Biesheuvel --- Documentation/arm64/booting.txt | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt index ab5a90adece3..5949bdbe7aac 100644 --- a/Documentation/arm64/booting.txt +++ b/Documentation/arm64/booting.txt @@ -115,8 +115,9 @@ The Image must be placed text_offset bytes from a 2MB aligned base address near the start of usable system RAM and called there. Memory below that base address is currently unusable by Linux, and therefore it is strongly recommended that this location is the start of system RAM. -At least image_size bytes from the start of the image must be free for -use by the kernel. +The physical memory region consisting of image_size bytes counting from +the start of the image must be free for use by the kernel, and must not +cross a 512 MB physical alignment boundary. Any memory described to the kernel (even that below the 2MB aligned base address) which is not marked as reserved from the kernel e.g. with a