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 70C75C4167B for ; Fri, 6 May 2022 11:45:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1391471AbiEFLtO (ORCPT ); Fri, 6 May 2022 07:49:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1391462AbiEFLs5 (ORCPT ); Fri, 6 May 2022 07:48:57 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80BD658E40; Fri, 6 May 2022 04:45:14 -0700 (PDT) Received: from dggpemm500021.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KvpXY6LH2zXdjf; Fri, 6 May 2022 19:40:29 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500021.china.huawei.com (7.185.36.109) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 6 May 2022 19:45:12 +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 15.1.2375.24; Fri, 6 May 2022 19:45:10 +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" , Dave Kleikamp Subject: [PATCH v24 3/6] arm64: kdump: Reimplement crashkernel=X Date: Fri, 6 May 2022 19:43:59 +0800 Message-ID: <20220506114402.365-4-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20220506114402.365-1-thunder.leizhen@huawei.com> References: <20220506114402.365-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Chen Zhou There are following issues in arm64 kdump: 1. We use crashkernel=X to reserve crashkernel in DMA zone, which will fail when there is not enough low memory. 2. If reserving crashkernel above DMA zone, in this case, crash dump kernel will fail to boot because there is no low memory available for allocation. To solve these issues, introduce crashkernel=X,[high,low]. The "crashkernel=X,high" is used to select a region above DMA zone, and the "crashkernel=Y,low" is used to allocate specified size low memory. Signed-off-by: Chen Zhou Co-developed-by: Zhen Lei Signed-off-by: Zhen Lei --- arch/arm64/kernel/machine_kexec.c | 9 +++- arch/arm64/kernel/machine_kexec_file.c | 12 ++++- arch/arm64/mm/init.c | 63 +++++++++++++++++++++++--- 3 files changed, 74 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index e16b248699d5c3c..19c2d487cb08feb 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -329,8 +329,13 @@ bool crash_is_nosave(unsigned long pfn) /* in reserved memory? */ addr = __pfn_to_phys(pfn); - if ((addr < crashk_res.start) || (crashk_res.end < addr)) - return false; + if ((addr < crashk_res.start) || (crashk_res.end < addr)) { + if (!crashk_low_res.end) + return false; + + if ((addr < crashk_low_res.start) || (crashk_low_res.end < addr)) + return false; + } if (!kexec_crash_image) return true; 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/mm/init.c b/arch/arm64/mm/init.c index 51863f1448c6989..18ba66c90991ea0 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -90,6 +90,32 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit; phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1; #endif +/* Current arm64 boot protocol requires 2MB alignment */ +#define CRASH_ALIGN SZ_2M + +#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit +#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1) + +static int __init reserve_crashkernel_low(unsigned long long low_size) +{ + unsigned long long low_base; + + low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX); + if (!low_base) { + pr_err("cannot allocate crashkernel low memory (size:0x%llx).\n", low_size); + return -ENOMEM; + } + + pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld MB)\n", + low_base, low_base + low_size, low_size >> 20); + + crashk_low_res.start = low_base; + crashk_low_res.end = low_base + low_size - 1; + insert_resource(&iomem_resource, &crashk_low_res); + + return 0; +} + /* * reserve_crashkernel() - reserves memory for crash kernel * @@ -100,17 +126,35 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1; static void __init reserve_crashkernel(void) { unsigned long long crash_base, crash_size; - unsigned long long crash_max = arm64_dma_phys_limit; + unsigned long long crash_low_size = 0; + unsigned long long crash_max = CRASH_ADDR_LOW_MAX; + char *cmdline = boot_command_line; int ret; if (!IS_ENABLED(CONFIG_KEXEC_CORE)) return; - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), + /* crashkernel=X[@offset] */ + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), &crash_size, &crash_base); - /* no crashkernel= or invalid value specified */ - if (ret || !crash_size) + if (ret == -ENOENT) { + ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base); + if (ret || !crash_size) + return; + + /* + * crashkernel=Y,low can be specified or not, but invalid value + * is not allowed. + */ + ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); + if (ret && (ret != -ENOENT)) + return; + + crash_max = CRASH_ADDR_HIGH_MAX; + } else if (ret || !crash_size) { + /* The specified value is invalid */ return; + } crash_size = PAGE_ALIGN(crash_size); @@ -118,8 +162,7 @@ static void __init reserve_crashkernel(void) if (crash_base) crash_max = crash_base + crash_size; - /* Current arm64 boot protocol requires 2MB alignment */ - crash_base = memblock_phys_alloc_range(crash_size, SZ_2M, + 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", @@ -127,6 +170,11 @@ static void __init reserve_crashkernel(void) return; } + if (crash_low_size && reserve_crashkernel_low(crash_low_size)) { + memblock_phys_free(crash_base, crash_size); + return; + } + pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", crash_base, crash_base + crash_size, crash_size >> 20); @@ -135,6 +183,9 @@ static void __init reserve_crashkernel(void) * map. Inform kmemleak so that it won't try to access it. */ kmemleak_ignore_phys(crash_base); + if (crashk_low_res.end) + kmemleak_ignore_phys(crashk_low_res.start); + crashk_res.start = crash_base; crashk_res.end = crash_base + crash_size - 1; insert_resource(&iomem_resource, &crashk_res); -- 2.25.1