From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 F0315C433E0 for ; Sun, 28 Jun 2020 08:30:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D623B20724 for ; Sun, 28 Jun 2020 08:30:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726227AbgF1Iaw (ORCPT ); Sun, 28 Jun 2020 04:30:52 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:59026 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726202AbgF1Iat (ORCPT ); Sun, 28 Jun 2020 04:30:49 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 25BDD937DB0F724DA0A4; Sun, 28 Jun 2020 16:30:45 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Sun, 28 Jun 2020 16:30:37 +0800 From: Chen Zhou To: , , , , , , , , , , , , , , CC: , , , , , , , Subject: [PATCH v9 5/5] kdump: update Documentation about crashkernel on arm64 Date: Sun, 28 Jun 2020 16:34:58 +0800 Message-ID: <20200628083458.40066-6-chenzhou10@huawei.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200628083458.40066-1-chenzhou10@huawei.com> References: <20200628083458.40066-1-chenzhou10@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now we support crashkernel=X,[low] on arm64, update the Documentation. We could use parameters "crashkernel=X crashkernel=Y,low" to reserve memory above 4G. Signed-off-by: Chen Zhou Tested-by: John Donnelly Tested-by: Prabhakar Kushwaha --- Documentation/admin-guide/kdump/kdump.rst | 13 +++++++++++-- Documentation/admin-guide/kernel-parameters.txt | 17 +++++++++++++++-- 2 files changed, 26 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst index 2da65fef2a1c..6ba294d425c9 100644 --- a/Documentation/admin-guide/kdump/kdump.rst +++ b/Documentation/admin-guide/kdump/kdump.rst @@ -299,7 +299,13 @@ Boot into System Kernel "crashkernel=64M@16M" tells the system kernel to reserve 64 MB of memory starting at physical address 0x01000000 (16MB) for the dump-capture kernel. - On x86 and x86_64, use "crashkernel=64M@16M". + On x86 use "crashkernel=64M@16M". + + On x86_64, use "crashkernel=Y[@X]" to select a region under 4G first, and + fall back to reserve region above 4G when '@offset' hasn't been specified. + We can also use "crashkernel=X,high" to select a region above 4G, which + also tries to allocate at least 256M below 4G automatically and + "crashkernel=Y,low" can be used to allocate specified size low memory. On ppc64, use "crashkernel=128M@32M". @@ -316,8 +322,11 @@ Boot into System Kernel kernel will automatically locate the crash kernel image within the first 512MB of RAM if X is not given. - On arm64, use "crashkernel=Y[@X]". Note that the start address of + On arm64, use "crashkernel=Y[@X]". Note that the start address of the kernel, X if explicitly specified, must be aligned to 2MiB (0x200000). + If crashkernel=Z,low is specified simultaneously, reserve spcified size + low memory for crash kdump kernel devices firstly and then reserve memory + above 4G. Load the Dump-capture Kernel ============================ diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb95fad81c79..335431a351c0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -722,6 +722,9 @@ [KNL, x86_64] select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. + [KNL, arm64] If crashkernel=X,low is specified, reserve + spcified size low memory for crash kdump kernel devices + firstly, and then reserve memory above 4G. See Documentation/admin-guide/kdump/kdump.rst for further details. crashkernel=range1:size1[,range2:size2,...][@offset] @@ -746,13 +749,23 @@ requires at least 64M+32K low memory, also enough extra low memory is needed to make sure DMA buffers for 32-bit devices won't run out. Kernel would try to allocate at - at least 256M below 4G automatically. + least 256M below 4G automatically. This one let user to specify own low range under 4G for second kernel instead. 0: to disable low allocation. It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. - + [KNL, arm64] range under 4G. + This one let user to specify own low range under 4G + for crash dump kernel instead. + Different with x86_64, kernel allocates specified size + physical memory region only when this parameter is specified + instead of trying to allocate at least 256M below 4G + automatically. + This parameter is used along with crashkernel=X when we + want to reserve crashkernel above 4G. If there are devices + need to use ZONE_DMA in crash dump kernel, it is also + a good choice. cryptomgr.notests [KNL] Disable crypto self-tests -- 2.20.1