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 E9239C433EF for ; Fri, 17 Jun 2022 02:40:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379552AbiFQCk4 (ORCPT ); Thu, 16 Jun 2022 22:40:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379530AbiFQCky (ORCPT ); Thu, 16 Jun 2022 22:40:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C8BCE64D1D for ; Thu, 16 Jun 2022 19:40:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655433652; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=O8SRq5MAXxm7CRGT0kP/ZVq+pjZMt/JpCdXhScXH7cM=; b=V3q5nWo1M5XEKWGD2En04w+DjUkEZoFv1lcqs2fNxrgjkfV6Xt9ml47zhf9/scWfAiwfu2 tyaTPqqm/Dyi5TEZ9eOEqqVJWCPOrjyJ7SjE/0oxWKJox2KoTLGeXhsxHu3GKnzTEgAJke Y1RbdA54nZ2m+SCj11QuM8Ts3ItNU8A= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-223-HNw1UsnqOpWWm1I1ODtVew-1; Thu, 16 Jun 2022 22:40:49 -0400 X-MC-Unique: HNw1UsnqOpWWm1I1ODtVew-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4D4BC382ECCB; Fri, 17 Jun 2022 02:40:48 +0000 (UTC) Received: from localhost (ovpn-12-144.pek2.redhat.com [10.72.12.144]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D13D7C08081; Fri, 17 Jun 2022 02:40:45 +0000 (UTC) Date: Fri, 17 Jun 2022 10:40:42 +0800 From: Baoquan He To: Zhen Lei Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Eric Biederman , Rob Herring , Frank Rowand , devicetree@vger.kernel.org, Dave Young , Vivek Goyal , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , John Donnelly , Dave Kleikamp Subject: Re: [PATCH 1/5] arm64: kdump: Provide default size when crashkernel=Y,low is not specified Message-ID: <20220617024042.GC234358@MiWiFi-R3L-srv> References: <20220613080932.663-1-thunder.leizhen@huawei.com> <20220613080932.663-2-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220613080932.663-2-thunder.leizhen@huawei.com> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/13/22 at 04:09pm, Zhen Lei wrote: > 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. This should correspond to the case that crashkernel=,high is explicitly specified, while crashkenrel=,low is omitted. It could be better to mention these. Otherwise, this looks good to me. > > Signed-off-by: Zhen Lei > --- > Documentation/admin-guide/kernel-parameters.txt | 8 +------- > arch/arm64/mm/init.c | 12 +++++++++++- > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 8090130b544b070..61b179232b68001 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,7 +843,7 @@ > 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. When crashkernel=X,high ~~~~ exceeds 80 characters, it should be OK. > 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 +857,6 @@ > 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 > 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3AA19C433EF for ; Fri, 17 Jun 2022 02:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8QZeV3dW3A3SrBSdDA7hKi6wV0VWmc92wIQAcnh6RjU=; b=rcuXuK+9DL/D2d oJ1g3cG4uz2JgsbI9ju+zwV8ziQlSllgt1RSkrWl0EAzx+9qNUrovQdDEhuZ0KxyNb3eV5hXULAhD FX84lUWWaYiZVxWKenSojS5N8f2ePOxF+RP6pntrSF0rccpVZY02RvM5z0NrV/lAFGlIiCTa2rSkr w260ARDq4ffQl2Ysf2OkGnfuYQ16vTAaOF8fbQ+/nSPr+H4eNc2zlJFfvKSif2dRy5OZV+XM6LahV 0VphEdjGquBvqVxOHrTXrGRxSHSQ3wVPLfnQWSSqFTDg5hOQuNP/72mZYXRMgoUzvrxBXcbSfJ7Sp Y1b2Y+Quy7jhh805SRMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o21uu-0059e9-9X; Fri, 17 Jun 2022 02:41:00 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o21uq-0059bW-Mf for kexec@lists.infradead.org; Fri, 17 Jun 2022 02:40:58 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655433652; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=O8SRq5MAXxm7CRGT0kP/ZVq+pjZMt/JpCdXhScXH7cM=; b=V3q5nWo1M5XEKWGD2En04w+DjUkEZoFv1lcqs2fNxrgjkfV6Xt9ml47zhf9/scWfAiwfu2 tyaTPqqm/Dyi5TEZ9eOEqqVJWCPOrjyJ7SjE/0oxWKJox2KoTLGeXhsxHu3GKnzTEgAJke Y1RbdA54nZ2m+SCj11QuM8Ts3ItNU8A= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-223-HNw1UsnqOpWWm1I1ODtVew-1; Thu, 16 Jun 2022 22:40:49 -0400 X-MC-Unique: HNw1UsnqOpWWm1I1ODtVew-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4D4BC382ECCB; Fri, 17 Jun 2022 02:40:48 +0000 (UTC) Received: from localhost (ovpn-12-144.pek2.redhat.com [10.72.12.144]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D13D7C08081; Fri, 17 Jun 2022 02:40:45 +0000 (UTC) Date: Fri, 17 Jun 2022 10:40:42 +0800 From: Baoquan He To: Zhen Lei Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Eric Biederman , Rob Herring , Frank Rowand , devicetree@vger.kernel.org, Dave Young , Vivek Goyal , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , John Donnelly , Dave Kleikamp Subject: Re: [PATCH 1/5] arm64: kdump: Provide default size when crashkernel=Y,low is not specified Message-ID: <20220617024042.GC234358@MiWiFi-R3L-srv> References: <20220613080932.663-1-thunder.leizhen@huawei.com> <20220613080932.663-2-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220613080932.663-2-thunder.leizhen@huawei.com> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220616_194056_851716_5E80584D X-CRM114-Status: GOOD ( 30.56 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On 06/13/22 at 04:09pm, Zhen Lei wrote: > 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. This should correspond to the case that crashkernel=,high is explicitly specified, while crashkenrel=,low is omitted. It could be better to mention these. Otherwise, this looks good to me. > > Signed-off-by: Zhen Lei > --- > Documentation/admin-guide/kernel-parameters.txt | 8 +------- > arch/arm64/mm/init.c | 12 +++++++++++- > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 8090130b544b070..61b179232b68001 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,7 +843,7 @@ > 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. When crashkernel=X,high ~~~~ exceeds 80 characters, it should be OK. > 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 +857,6 @@ > 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 > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A982EC433EF for ; Fri, 17 Jun 2022 02:42:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Vt727CoR5pwx5k4BfhWCh+qZP8f2vYA5F5/b1ZwGSck=; b=22S2+HBDb+8TEz rAdh1GnTO51jDAUwRF5hEdYb/b5bzjNCDx0D4k4kgj0vJGtbeNDVrAMOGsbxvM3Dtb6RMKrn+boM0 syKhGu9ztHK4eB0ugpLg+Lbw8U98hIWxqsGzdvIzzeySickmL2AkO9rjhmTBYX2eLNjFWohpRi0Nb b97TuhyfNfdZm5k37J8jUQmbnhMvJQN6BJPw/kFA6R7hCbXWehx5kYOat40WBLMNw2ImZl4RDmxQp utZyF6K2iMxtoBFWOsVJdYKXtig9x1lpiGernZ8tfpY+yxKkwGD2BQpeLK8pv79ylR/KPxU+AE5mO W6ieAB257Xt4g292M89w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o21uv-0059eL-Tm; Fri, 17 Jun 2022 02:41:02 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o21uq-0059bV-QT for linux-arm-kernel@lists.infradead.org; Fri, 17 Jun 2022 02:40:58 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1655433652; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=O8SRq5MAXxm7CRGT0kP/ZVq+pjZMt/JpCdXhScXH7cM=; b=V3q5nWo1M5XEKWGD2En04w+DjUkEZoFv1lcqs2fNxrgjkfV6Xt9ml47zhf9/scWfAiwfu2 tyaTPqqm/Dyi5TEZ9eOEqqVJWCPOrjyJ7SjE/0oxWKJox2KoTLGeXhsxHu3GKnzTEgAJke Y1RbdA54nZ2m+SCj11QuM8Ts3ItNU8A= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-223-HNw1UsnqOpWWm1I1ODtVew-1; Thu, 16 Jun 2022 22:40:49 -0400 X-MC-Unique: HNw1UsnqOpWWm1I1ODtVew-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4D4BC382ECCB; Fri, 17 Jun 2022 02:40:48 +0000 (UTC) Received: from localhost (ovpn-12-144.pek2.redhat.com [10.72.12.144]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D13D7C08081; Fri, 17 Jun 2022 02:40:45 +0000 (UTC) Date: Fri, 17 Jun 2022 10:40:42 +0800 From: Baoquan He To: Zhen Lei Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Eric Biederman , Rob Herring , Frank Rowand , devicetree@vger.kernel.org, Dave Young , Vivek Goyal , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , John Donnelly , Dave Kleikamp Subject: Re: [PATCH 1/5] arm64: kdump: Provide default size when crashkernel=Y,low is not specified Message-ID: <20220617024042.GC234358@MiWiFi-R3L-srv> References: <20220613080932.663-1-thunder.leizhen@huawei.com> <20220613080932.663-2-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220613080932.663-2-thunder.leizhen@huawei.com> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220616_194056_959003_B268D40E X-CRM114-Status: GOOD ( 31.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 06/13/22 at 04:09pm, Zhen Lei wrote: > 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. This should correspond to the case that crashkernel=,high is explicitly specified, while crashkenrel=,low is omitted. It could be better to mention these. Otherwise, this looks good to me. > > Signed-off-by: Zhen Lei > --- > Documentation/admin-guide/kernel-parameters.txt | 8 +------- > arch/arm64/mm/init.c | 12 +++++++++++- > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 8090130b544b070..61b179232b68001 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,7 +843,7 @@ > 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. When crashkernel=X,high ~~~~ exceeds 80 characters, it should be OK. > 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 +857,6 @@ > 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 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel