From nobody Thu Apr 2 15:37:45 2026 Received: from canpmsgout09.his.huawei.com (canpmsgout09.his.huawei.com [113.46.200.224]) (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 EA80638BF75; Thu, 2 Apr 2026 07:26:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.224 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775114796; cv=none; b=QWfg7zw+Ygf9pSNxGBmRVPaB9hQ1vzB6U/EXItxV/YglMiJXDHyU+lStXHjTOd6I4E4oAZaUpuDaR4lAhp9htQTnhyUshx1In6TtlDbbSJZ5ciHNGVRfGIn7z9cDzxAGHB88k53CY1cjxnzLwMtD4lMazOjwcQ7m+tJH/jZbXmw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775114796; c=relaxed/simple; bh=N1y2onTjOuUNUA2WShqrni1d80bsFe5QHnBqQhczUKk=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=suO8xDirYxcTyIabk8V+j5ZD1JJtWSuqOzhcqus2EIZz8xG9iPCwAGPwvJrQSpgH+J1VBNvuQDh5StE6wADhLY1B8jM/z56zA0qqdbammJ53MjRaaF5lj90dJzm7eltu6/wY9oyDlithfQSZm8vdLCc7phpMW/r90AMn7b0AVPM= 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=XG5yIWzK; arc=none smtp.client-ip=113.46.200.224 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="XG5yIWzK" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=HnOZBoE7o/6/IAIFfJRvYly50aiP5r33Q2nsL/6jnAk=; b=XG5yIWzKdNW6ZIUY1IeNuIEmda+qjNe0mzM2RASvpMLKA0VQyQ/lc6+rvBeGvBX+PHLq0rmN8 6maPKZC3t1oDwPlnVH2scDHAWSypKM/eoZXO8x2x3aPMSOnuwmoXvUB0FMtVLUEM+QRz81W/Ad+ TQceOxVP8w3Sk+4wK8jsbiM= Received: from mail.maildlp.com (unknown [172.19.163.200]) by canpmsgout09.his.huawei.com (SkyGuard) with ESMTPS id 4fmYCp0Fxvz1cyPr; Thu, 2 Apr 2026 15:20:22 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 906E84056D; Thu, 2 Apr 2026 15:26:31 +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; Thu, 2 Apr 2026 15:26:28 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v12 15/15] riscv: kexec: Add support for crashkernel CMA reservation Date: Thu, 2 Apr 2026 15:27:01 +0800 Message-ID: <20260402072701.628293-16-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260402072701.628293-1-ruanjinjie@huawei.com> References: <20260402072701.628293-1-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: kwepems100002.china.huawei.com (7.221.188.206) 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, which was already done in of_kexec_alloc_and_setup_fdt(). - Exclude the CMA-reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore, which was already done in the crash core. Update kernel-parameters.txt to document CMA support for crashkernel on riscv architecture. Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Alexandre Ghiti Acked-by: Baoquan He Acked-by: Mike Rapoport (Microsoft) Acked-by: Paul Walmsley # arch/riscv Signed-off-by: Jinjie Ruan --- Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++-------- arch/riscv/kernel/machine_kexec_file.c | 2 +- arch/riscv/mm/init.c | 5 +++-- 3 files changed, 12 insertions(+), 11 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index a7055cead40f..13ced9ea42f4 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1122,14 +1122,14 @@ 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 bea818f75dd6..c79cd86d5713 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -46,7 +46,7 @@ static int get_nr_ram_ranges_callback(struct resource *re= s, void *arg) =20 unsigned int arch_get_system_nr_ranges(void) { - unsigned int nr_ranges =3D 2; /* For exclusion of crashkernel region */ + unsigned int nr_ranges =3D 2 + crashk_cma_cnt; /* For exclusion of crashk= ernel region */ =20 walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); =20 diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 811e03786c56..4cd49afa9077 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1398,7 +1398,7 @@ 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; @@ -1408,11 +1408,12 @@ 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