From patchwork Tue Mar 28 06:52:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 744094 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vshMz2BjPz9s79 for ; Tue, 28 Mar 2017 17:49:51 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b="DRQ8VF48"; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754137AbdC1Gtu (ORCPT ); Tue, 28 Mar 2017 02:49:50 -0400 Received: from mail-pg0-f53.google.com ([74.125.83.53]:35091 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753934AbdC1Gtt (ORCPT ); Tue, 28 Mar 2017 02:49:49 -0400 Received: by mail-pg0-f53.google.com with SMTP id 81so49067195pgh.2 for ; Mon, 27 Mar 2017 23:49:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=qoGTX5qJmqJbCg9RP9uc/PJG8OTVrm/xdcL56EzL+VQ=; b=DRQ8VF48jq/DN7rqEoAs+RvMNgAfHEihHkmRqvCmvHdO1ijvbXC76x0z3A7WD1tEcs j1podqv5cHkTVQEU/rMWz05PgVyIVLTuaOK5QQOuQ337soBnmBoAbKggdJaQs3qXmFn9 vhif4McnEb6qgoxHxg44Xx6slLcwKAKmF4jEw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=qoGTX5qJmqJbCg9RP9uc/PJG8OTVrm/xdcL56EzL+VQ=; b=sNdPomq7DMsZLzl6x7sNd7DieU/mSEdiXdy+CQRnuAmVCYFs+R7/c/IPYSoe3czKed UDs4PfnoThmT28fAtGzBIGO/gFdlRRzqv4NVHPhegHNcwvKjH4wKpKE07GhIJMaNclXt udTD+4BWSyvZiJ17rda3jw5QK71kMeju4+zQqGeTWP/TPd0sr1igTKPcZeTR3Bhg8wwG wzR3tWj7aOn7tbhbD7ieqKwurq7RNnkRUcdVRkLLT6dT8MTKwhUDJFYV35uK9Ry3OU2s oj0SLdNHAgMEuJdPCLJ3sqEazwpV30ZcDI/zCVr3gryEZieNF2qUarRlt/YQwh48rSg7 uVWw== X-Gm-Message-State: AFeK/H3eLmqVeo+JDFLUpU90UAr53o9XuA4s9Lg7/tsrBjUwL08A4ZAhZKUcsjJF2ZQHNLoW X-Received: by 10.84.131.79 with SMTP id 73mr33488499pld.45.1490683788192; Mon, 27 Mar 2017 23:49:48 -0700 (PDT) Received: from linaro.org ([121.95.100.191]) by smtp.googlemail.com with ESMTPSA id 20sm4906128pgg.52.2017.03.27.23.49.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Mar 2017 23:49:47 -0700 (PDT) From: AKASHI Takahiro To: catalin.marinas@arm.com, will.deacon@arm.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: james.morse@arm.com, geoff@infradead.org, bauerman@linux.vnet.ibm.com, dyoung@redhat.com, ard.biesheuvel@linaro.org, panand@redhat.com, sgoel@codeaurora.org, dwmw2@infradead.org, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, AKASHI Takahiro Subject: [PATCH v34 13/14] Documentation: dt: chosen properties for arm64 kdump Date: Tue, 28 Mar 2017 15:52:42 +0900 Message-Id: <20170328065242.16108-1-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.11.1 In-Reply-To: <20170328064831.15894-1-takahiro.akashi@linaro.org> References: <20170328064831.15894-1-takahiro.akashi@linaro.org> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: James Morse Add documentation for DT properties: linux,usable-memory-range linux,elfcorehdr used by arm64 kdump. Those are, respectively, a usable memory range allocated to crash dump kernel and the elfcorehdr's location within it. Signed-off-by: James Morse [takahiro.akashi@linaro.org: update the text due to recent changes ] Signed-off-by: AKASHI Takahiro Acked-by: Mark Rutland Cc: devicetree@vger.kernel.org Cc: Rob Herring --- Documentation/devicetree/bindings/chosen.txt | 45 ++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index 6ae9d82d4c37..b5e39af4ddc0 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -52,3 +52,48 @@ This property is set (currently only on PowerPC, and only needed on book3e) by some versions of kexec-tools to tell the new kernel that it is being booted by kexec, as the booting environment may differ (e.g. a different secondary CPU release mechanism) + +linux,usable-memory-range +------------------------- + +This property (arm64 only) holds a base address and size, describing a +limited region in which memory may be considered available for use by +the kernel. Memory outside of this range is not available for use. + +This property describes a limitation: memory within this range is only +valid when also described through another mechanism that the kernel +would otherwise use to determine available memory (e.g. memory nodes +or the EFI memory map). Valid memory may be sparse within the range. +e.g. + +/ { + chosen { + linux,usable-memory-range = <0x9 0xf0000000 0x0 0x10000000>; + }; +}; + +The main usage is for crash dump kernel to identify its own usable +memory and exclude, at its boot time, any other memory areas that are +part of the panicked kernel's memory. + +While this property does not represent a real hardware, the address +and the size are expressed in #address-cells and #size-cells, +respectively, of the root node. + +linux,elfcorehdr +---------------- + +This property (currently used only on arm64) holds the memory range, +the address and the size, of the elf core header which mainly describes +the panicked kernel's memory layout as PT_LOAD segments of elf format. +e.g. + +/ { + chosen { + linux,elfcorehdr = <0x9 0xfffff000 0x0 0x800>; + }; +}; + +While this property does not represent a real hardware, the address +and the size are expressed in #address-cells and #size-cells, +respectively, of the root node.