From nobody Mon Apr 13 21:41:05 2026 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 25358C433FE for ; Wed, 16 Nov 2022 12:17:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233517AbiKPMRr (ORCPT ); Wed, 16 Nov 2022 07:17:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233201AbiKPMQa (ORCPT ); Wed, 16 Nov 2022 07:16:30 -0500 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD898192A0; Wed, 16 Nov 2022 04:10:59 -0800 (PST) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4NC21m3JKWz15Mh0; Wed, 16 Nov 2022 20:10:36 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 16 Nov 2022 20:10:58 +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 15.1.2375.31; Wed, 16 Nov 2022 20:10:57 +0800 From: Zhen Lei To: Dave Young , Baoquan He , Vivek Goyal , , , Catalin Marinas , Will Deacon , , Jonathan Corbet , CC: Zhen Lei , "Eric W . Biederman" , Randy Dunlap , Feng Zhou , Kefeng Wang , "Chen Zhou" , John Donnelly , Dave Kleikamp Subject: [PATCH v4 2/2] arm64: kdump: Support crashkernel=X fall back to reserve region above DMA zones Date: Wed, 16 Nov 2022 20:10:44 +0800 Message-ID: <20221116121044.1690-3-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.37.3.windows.1 In-Reply-To: <20221116121044.1690-1-thunder.leizhen@huawei.com> References: <20221116121044.1690-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" For crashkernel=3DX without '@offset', select a region within DMA zones first, and fall back to reserve region above DMA zones. This allows users to use the same configuration on multiple platforms. Signed-off-by: Zhen Lei Acked-by: Baoquan He Reviewed-by: Catalin Marinas --- Documentation/admin-guide/kernel-parameters.txt | 2 +- arch/arm64/mm/init.c | 17 ++++++++++++++++- 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index a7b7147447b8bf8..ef6d922ed26b9dc 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -842,7 +842,7 @@ memory region [offset, offset + size] for that kernel image. If '@offset' is omitted, then a suitable offset is selected automatically. - [KNL, X86-64] Select a region under 4G first, and + [KNL, X86-64, ARM64] Select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. See Documentation/admin-guide/kdump/kdump.rst for further details. diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index ba7227179822d10..58a0bb2c17f18cf 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -132,6 +132,7 @@ static void __init reserve_crashkernel(void) unsigned long long crash_max =3D CRASH_ADDR_LOW_MAX; char *cmdline =3D boot_command_line; int ret; + bool fixed_base =3D false; =20 if (!IS_ENABLED(CONFIG_KEXEC_CORE)) return; @@ -163,12 +164,26 @@ static void __init reserve_crashkernel(void) crash_size =3D PAGE_ALIGN(crash_size); =20 /* User specifies base address explicitly. */ - if (crash_base) + if (crash_base) { + fixed_base =3D true; crash_max =3D crash_base + crash_size; + } =20 +retry: crash_base =3D memblock_phys_alloc_range(crash_size, CRASH_ALIGN, crash_base, crash_max); if (!crash_base) { + /* + * If the first attempt was for low memory, fall back to + * high memory, the minimum required low memory will be + * reserved later. + */ + if (!fixed_base && (crash_max =3D=3D CRASH_ADDR_LOW_MAX)) { + crash_max =3D CRASH_ADDR_HIGH_MAX; + crash_low_size =3D DEFAULT_CRASH_KERNEL_LOW_SIZE; + goto retry; + } + pr_warn("cannot allocate crashkernel (size:0x%llx)\n", crash_size); return; --=20 2.25.1