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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61DC2CCA473 for ; Thu, 9 Jun 2022 13:54:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243290AbiFINy4 (ORCPT ); Thu, 9 Jun 2022 09:54:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243525AbiFINyz (ORCPT ); Thu, 9 Jun 2022 09:54:55 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 96844563A1; Thu, 9 Jun 2022 06:54:53 -0700 (PDT) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LJltJ296wzjXKF; Thu, 9 Jun 2022 21:53:28 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 9 Jun 2022 21:54:50 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 9 Jun 2022 21:54:49 +0800 From: Zhen Lei To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , , "H . Peter Anvin" , Eric Biederman , Rob Herring , Frank Rowand , , Dave Young , Baoquan He , Vivek Goyal , , , Catalin Marinas , Will Deacon , , Jonathan Corbet , CC: Zhen Lei , Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , "John Donnelly" , Dave Kleikamp Subject: [PATCH] arm64: kdump: Provide default size when crashkernel=Y,low is not specified Date: Thu, 9 Jun 2022 21:50:29 +0800 Message-ID: <20220609135029.607-1-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org To be consistent with the implementation of x86 and improve cross-platform user experience. Try to allocate at least 256 MiB low memory automatically when crashkernel=Y,low is not specified. Signed-off-by: Zhen Lei --- Documentation/admin-guide/kernel-parameters.txt | 10 +++------- arch/arm64/mm/init.c | 12 +++++++++++- 2 files changed, 14 insertions(+), 8 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 8090130b544b070..9560f5af248e0d6 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -843,7 +843,9 @@ available. It will be ignored if crashkernel=X is specified. crashkernel=size[KMG],low - [KNL, X86-64] range under 4G. When crashkernel=X,high + [KNL, X86-64, ARM64] range under 4G(For some platforms, + not all low 4G memory can be directly accessed by devices, + use the DMA zones instead). When crashkernel=X,high is passed, kernel could allocate physical memory region above 4G, that cause second kernel crash on system that require some amount of low memory, e.g. swiotlb @@ -857,12 +859,6 @@ It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. - [KNL, ARM64] range in low memory. - This one lets the user specify a low range in the - DMA zone for the crash dump kernel. - It will be ignored when crashkernel=X,high is not used - or memory reserved is located in the DMA zones. - cryptomgr.notests [KNL] Disable crypto self-tests diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 339ee84e5a61a0b..5390f361208ccf7 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -96,6 +96,14 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1; #define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit #define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1) +/* + * This is an empirical value in x86_64 and taken here directly. Please + * refer to the code comment in reserve_crashkernel_low() of x86_64 for more + * details. + */ +#define DEFAULT_CRASH_KERNEL_LOW_SIZE \ + max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20) + static int __init reserve_crashkernel_low(unsigned long long low_size) { unsigned long long low_base; @@ -147,7 +155,9 @@ static void __init reserve_crashkernel(void) * is not allowed. */ ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); - if (ret && (ret != -ENOENT)) + if (ret == -ENOENT) + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; + else if (ret) return; crash_max = CRASH_ADDR_HIGH_MAX; -- 2.25.1