From patchwork Tue Dec 28 13:26:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen \(ThunderTown\)" X-Patchwork-Id: 529372 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 9F0BFC433EF for ; Tue, 28 Dec 2021 13:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232941AbhL1N3k (ORCPT ); Tue, 28 Dec 2021 08:29:40 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:15986 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233224AbhL1N3I (ORCPT ); Tue, 28 Dec 2021 08:29:08 -0500 Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4JNZzd17m4zZdgP; Tue, 28 Dec 2021 21:25:49 +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 15.1.2308.20; Tue, 28 Dec 2021 21:29:06 +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 15.1.2308.20; Tue, 28 Dec 2021 21:29:05 +0800 From: Zhen Lei To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , , "H . Peter Anvin" , , Dave Young , Baoquan He , Vivek Goyal , Eric Biederman , , Catalin Marinas , "Will Deacon" , , Rob Herring , Frank Rowand , , Jonathan Corbet , CC: Zhen Lei , Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , "John Donnelly" Subject: [PATCH v19 11/13] arm64: kdump: reimplement crashkernel=X Date: Tue, 28 Dec 2021 21:26:10 +0800 Message-ID: <20211228132612.1860-12-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20211228132612.1860-1-thunder.leizhen@huawei.com> References: <20211228132612.1860-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Chen Zhou There are following issues in arm64 kdump: 1. We use crashkernel=X to reserve crashkernel below 4G, which will fail when there is no enough low memory. 2. If reserving crashkernel above 4G, in this case, crash dump kernel will boot failure because there is no low memory available for allocation. To solve these issues, change the behavior of crashkernel=X and introduce crashkernel=X,[high,low]. crashkernel=X tries low allocation in DMA zone, and fall back to high allocation if it fails. We can also use "crashkernel=X,high" to select a region above DMA zone, which also tries to allocate at least 256M in DMA zone automatically. "crashkernel=Y,low" can be used to allocate specified size low memory. Another minor change, there may be two regions reserved for crash dump kernel, in order to distinct from the high region and make no effect to the use of existing kexec-tools, rename the low region as "Crash kernel (low)". Signed-off-by: Chen Zhou Co-developed-by: Zhen Lei Signed-off-by: Zhen Lei --- arch/arm64/kernel/machine_kexec.c | 5 +++- arch/arm64/kernel/machine_kexec_file.c | 12 ++++++-- arch/arm64/kernel/setup.c | 13 +++++++- arch/arm64/mm/init.c | 41 ++++++++++---------------- 4 files changed, 42 insertions(+), 29 deletions(-) diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 6fb31c117ebe08c..6665bf31f6b6a19 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -327,7 +327,10 @@ bool crash_is_nosave(unsigned long pfn) /* in reserved memory? */ addr = __pfn_to_phys(pfn); - if ((addr < crashk_res.start) || (crashk_res.end < addr)) + if (((addr < crashk_res.start) || (crashk_res.end < addr)) && !crashk_low_res.end) + return false; + + if ((addr < crashk_low_res.start) || (crashk_low_res.end < addr)) return false; if (!kexec_crash_image) diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index 59c648d51848886..889951291cc0f9c 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -65,10 +65,18 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) /* Exclude crashkernel region */ ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); + if (ret) + goto out; + + if (crashk_low_res.end) { + ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end); + if (ret) + goto out; + } - if (!ret) - ret = crash_prepare_elf64_headers(cmem, true, addr, sz); + ret = crash_prepare_elf64_headers(cmem, true, addr, sz); +out: kfree(cmem); return ret; } diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index be5f85b0a24de69..4bb2e55366be64d 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -248,7 +248,18 @@ static void __init request_standard_resources(void) kernel_data.end <= res->end) request_resource(res, &kernel_data); #ifdef CONFIG_KEXEC_CORE - /* Userspace will find "Crash kernel" region in /proc/iomem. */ + /* + * Userspace will find "Crash kernel" or "Crash kernel (low)" + * region in /proc/iomem. + * In order to distinct from the high region and make no effect + * to the use of existing kexec-tools, rename the low region as + * "Crash kernel (low)". + */ + if (crashk_low_res.end && crashk_low_res.start >= res->start && + crashk_low_res.end <= res->end) { + crashk_low_res.name = "Crash kernel (low)"; + request_resource(res, &crashk_low_res); + } if (crashk_res.end && crashk_res.start >= res->start && crashk_res.end <= res->end) request_resource(res, &crashk_res); diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index be4595dc7459115..91b8038a1529068 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -74,41 +74,32 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init; */ static void __init reserve_crashkernel(void) { - unsigned long long crash_base, crash_size; - unsigned long long crash_max = CRASH_ADDR_LOW_MAX; + unsigned long long crash_size, crash_base, total_mem, low_size; + bool high = false; int ret; - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), - &crash_size, &crash_base); - /* no crashkernel= or invalid value specified */ - if (ret || !crash_size) - return; - - crash_size = PAGE_ALIGN(crash_size); - - /* User specifies base address explicitly. */ - if (crash_base) - crash_max = crash_base + crash_size; + total_mem = memblock_phys_mem_size(); - /* Current arm64 boot protocol requires 2MB alignment */ - crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, - crash_base, crash_max); - if (!crash_base) { - pr_warn("cannot allocate crashkernel (size:0x%llx)\n", - crash_size); - return; + ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); + if (ret != 0 || crash_size <= 0) { + /* crashkernel=X,high and possible crashkernel=Y,low */ + ret = parse_crashkernel_high_low(boot_command_line, &crash_size, &low_size); + if (ret) + return; + high = true; } - pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", - crash_base, crash_base + crash_size, crash_size >> 20); + ret = reserve_crashkernel_mem(total_mem, crash_size, crash_base, low_size, high); + if (ret) + return; /* * The crashkernel memory will be removed from the kernel linear * map. Inform kmemleak so that it won't try to access it. */ - kmemleak_ignore_phys(crash_base); - crashk_res.start = crash_base; - crashk_res.end = crash_base + crash_size - 1; + kmemleak_ignore_phys(crashk_res.start); + if (crashk_low_res.end) + kmemleak_ignore_phys(crashk_low_res.start); } #else static void __init reserve_crashkernel(void)