From nobody Tue Feb 10 02:49:37 2026 Received: from canpmsgout06.his.huawei.com (canpmsgout06.his.huawei.com [113.46.200.221]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1167F39A7E1; Wed, 4 Feb 2026 09:36:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.221 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770197809; cv=none; b=GI+SATEKcE10ybu7IHJR9BD+w+G6w88aU+jICHNGiRSANbyPQuiR+p95ViXwjfxLkYZbGvj5pwb6bZAFtfrPJ0ff8aM+PGTynIUq9w5prtO2Fp+aHQEa6JVn4p5cj5V7R3gF9FB9w9yzEQw8uqvmYTCP7UBDmxQtRjxsVoTKr8w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770197809; c=relaxed/simple; bh=rXV050Kc/51xmlnP83x+nk533vY/vf8jfe67EQdWqQg=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=J4nt/EUMIZ3qW//1SrfIbDGbDiuyugRoBOtQWxmeO+wEoD1TvdEIH3RJ9hBBKR7ZxoobuxSaDDKxQTbk3FbjyFC86uiwkfNvx8AG+BEh418Uzd1jlY6XopCwU9AsFWC7W3a9zgiFQxwm3QYTx+ZEl7/1AQsfuMO0ws2D3B3Vt+0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=Piy+D2Ae; arc=none smtp.client-ip=113.46.200.221 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="Piy+D2Ae" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=JCg+l/0tXKCFf/mTir6vjlLYgbGXrZ03085YKEzTp9o=; b=Piy+D2Ae8+BF6TNKkVTiXKJnuFRuLSxDv9GIoqvekPwAbC38MSuPzE4rdAmNy3fDxpahTOecm sKzwPjEQ0ep8SD+2yLXGpYWSH2DZhEAqorz6ufVLlnMdITs3Fz1ny860+YBmJ0BWnHjZrHjvE/C Qjz9qZbGW0FgfxFyHLhAxEY= Received: from mail.maildlp.com (unknown [172.19.162.223]) by canpmsgout06.his.huawei.com (SkyGuard) with ESMTPS id 4f5ZrF0Lt0zRhRB; Wed, 4 Feb 2026 17:32:13 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id A83CA40561; Wed, 4 Feb 2026 17:36:46 +0800 (CST) Received: from huawei.com (10.90.53.73) by dggpemf500011.china.huawei.com (7.185.36.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 4 Feb 2026 17:36:43 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v3 3/3] riscv: kexec: Add support for crashkernel CMA reservation Date: Wed, 4 Feb 2026 17:37:28 +0800 Message-ID: <20260204093728.1447527-4-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260204093728.1447527-1-ruanjinjie@huawei.com> References: <20260204093728.1447527-1-ruanjinjie@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To dggpemf500011.china.huawei.com (7.185.36.131) Content-Type: text/plain; charset="utf-8" Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the crashkernel=3D command line option") and commit ab475510e042 ("kdump: implement reserve_crashkernel_cma") added CMA support for kdump crashkernel reservation. This allows the kernel to dynamically allocate contiguous memory for crash dumping when needed, rather than permanently reserving a fixed region at boot time. So extend crashkernel CMA reservation support to riscv. The following changes are made to enable CMA reservation: - Parse and obtain the CMA reservation size along with other crashkernel parameters. - Call reserve_crashkernel_cma() to allocate the CMA region for kdump. - Include the CMA-reserved ranges for kdump kernel to use. - Exclude the CMA-reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore, which is already done in the crash core. Update kernel-parameters.txt to document CMA support for crashkernel on riscv architecture. Signed-off-by: Jinjie Ruan --- Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++-------- arch/riscv/kernel/machine_kexec_file.c | 10 ++++++++-- arch/riscv/mm/init.c | 5 +++-- 3 files changed, 19 insertions(+), 12 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 36bb642a7edd..3b92324d3a03 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1119,14 +1119,14 @@ Kernel parameters It will be ignored when crashkernel=3DX,high is not used or memory reserved is below 4G. crashkernel=3Dsize[KMG],cma - [KNL, X86, ARM64, ppc] Reserve additional crash kernel memory from - CMA. This reservation is usable by the first system's - userspace memory and kernel movable allocations (memory - balloon, zswap). Pages allocated from this memory range - will not be included in the vmcore so this should not - be used if dumping of userspace memory is intended and - it has to be expected that some movable kernel pages - may be missing from the dump. + [KNL, X86, ARM64, RISCV, ppc] Reserve additional crash + kernel memory from CMA. This reservation is usable by + the first system's userspace memory and kernel movable + allocations (memory balloon, zswap). Pages allocated + from this memory range will not be included in the vmcore + so this should not be used if dumping of userspace memory + is intended and it has to be expected that some movable + kernel pages may be missing from the dump. =20 A standard crashkernel reservation, as described above, is still needed to hold the crash kernel and initrd. diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/mac= hine_kexec_file.c index fec3622a13c9..0e4ac70d5a9a 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -59,9 +59,9 @@ static int prepare_elf_headers(void **addr, unsigned long= *sz) { struct crash_mem *cmem; unsigned int nr_ranges; - int ret; + int ret, i; =20 - nr_ranges =3D 1; /* For exclusion of crashkernel region */ + nr_ranges =3D 1 + crashk_cma_cnt; /* For exclusion of crashkernel region = */ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); =20 cmem =3D kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL); @@ -74,6 +74,12 @@ static int prepare_elf_headers(void **addr, unsigned lon= g *sz) if (ret) goto out; =20 + for (i =3D 0; i < crashk_cma_cnt; i++) { + cmem->ranges[cmem->nr_ranges].start =3D crashk_cma_ranges[i].start; + cmem->ranges[cmem->nr_ranges].end =3D crashk_cma_ranges[i].end; + cmem->nr_ranges++; + } + ret =3D crash_prepare_elf64_headers(cmem, true, addr, sz); =20 out: diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index addb8a9305be..074d2d5f79ee 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1404,7 +1404,7 @@ static inline void setup_vm_final(void) */ static void __init arch_reserve_crashkernel(void) { - unsigned long long low_size =3D 0; + unsigned long long low_size =3D 0, cma_size =3D 0; unsigned long long crash_base, crash_size; bool high =3D false; int ret; @@ -1414,11 +1414,12 @@ static void __init arch_reserve_crashkernel(void) =20 ret =3D parse_crashkernel(boot_command_line, memblock_phys_mem_size(), &crash_size, &crash_base, - &low_size, NULL, &high); + &low_size, &cma_size, &high); if (ret) return; =20 reserve_crashkernel_generic(crash_size, crash_base, low_size, high); + reserve_crashkernel_cma(cma_size); } =20 void __init paging_init(void) --=20 2.34.1