From patchwork Tue Aug 29 12:16:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baoquan He X-Patchwork-Id: 13368933 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 74363C6FA8F for ; Tue, 29 Aug 2023 12:17:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=/Ol4RyjqQs8ivvJsyubKYkwMpDPlq5DfGVOsfHdaGYE=; b=nuOBbSuFEfPMgc ekxdGqvUOJoL/CCQchObWwTeEIjQwJgZGXfZGSvFjh3KcjC39+zHW9mJRT79YuBAhEvuLjMP04OX/ NaghtUpZVNujIZPy/DgkYmef8hoWXTxWCz+UMLB6jIuLWs1KaIXI9y1oQf5KkaySg38xYriKWG3uI svfTJHlDLOPM7b+bFxTs7hzpV7JCS9DntX4w0TAFuy2Tf6A17saLU8kswYjG19Cw/mevfI99WFgbW qHJlJk0O3teC/WGHker3Rt7x8NRsVgYPklyBhr3FL8OUlMlg6B1wdDeyGb1scjVCufyroEoE5p2qe JxgtuGclu9v+LkO8NnCw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qaxee-00BTqM-1a; Tue, 29 Aug 2023 12:17:08 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qaxeO-00BThB-2p for linux-arm-kernel@lists.infradead.org; Tue, 29 Aug 2023 12:16:54 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1693311412; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=93M1IuRa9hF+e3rvbfoWcz/IWOp8pvfcunsOvCb1h/c=; b=gPtMf0/CE0CudTl/jGfEa7UM1Pz895iLhaSkBNrcqCvfPgF0qoTY37N8+LMb+A7WkFjFem VwOPAHVY3KDBeHG76EKimpJtrR3CReYqLOXvvWcLC/cjFnJTj5xGxSbNQb78wiLuRpp18Q /YNan/HIREVHBZ/6Y7bMBYx/t3WbHA4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-403-LNEm2wGVMF-0JtOAzQ7SZQ-1; Tue, 29 Aug 2023 08:16:48 -0400 X-MC-Unique: LNEm2wGVMF-0JtOAzQ7SZQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3B34F85CBF4; Tue, 29 Aug 2023 12:16:48 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.112.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1491E6B2AD; Tue, 29 Aug 2023 12:16:43 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, catalin.marinas@arm.com, thunder.leizhen@huawei.com, dyoung@redhat.com, prudo@redhat.com, samuel.holland@sifive.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, Baoquan He Subject: [PATCH v2 6/8] x86: kdump: use generic interface to simplify crashkernel reservation code Date: Tue, 29 Aug 2023 20:16:08 +0800 Message-ID: <20230829121610.138107-7-bhe@redhat.com> In-Reply-To: <20230829121610.138107-1-bhe@redhat.com> References: <20230829121610.138107-1-bhe@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230829_051652_983012_6820B177 X-CRM114-Status: GOOD ( 29.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org With the help of newly changed function parse_crashkernel() and generic reserve_crashkernel_generic(), crashkernel reservation can be simplified by steps: 1) Add a new header file , and define CRASH_ALIGN, CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and DEFAULT_CRASH_KERNEL_LOW_SIZE in ; 2) Add arch_reserve_crashkernel() to call parse_crashkernel() and reserve_crashkernel_generic(), and do the ARCH specific work if needed. 3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in arch/x86/Kconfig. When adding DEFAULT_CRASH_KERNEL_LOW_SIZE, add crash_low_size_default() to calculate crashkernel low memory because x86_64 has special requirement. The old reserve_crashkernel_low() and reserve_crashkernel() can be removed. Signed-off-by: Baoquan He Signed-off-by: Baoquan He --- arch/x86/Kconfig | 3 + arch/x86/include/asm/crash_core.h | 34 +++++++ arch/x86/kernel/setup.c | 144 ++++-------------------------- 3 files changed, 53 insertions(+), 128 deletions(-) create mode 100644 arch/x86/include/asm/crash_core.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8d9e4b362572..c4539dc35985 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2037,6 +2037,9 @@ config KEXEC_FILE config ARCH_HAS_KEXEC_PURGATORY def_bool KEXEC_FILE +config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION + def_bool CRASH_CORE + config KEXEC_SIG bool "Verify kernel signature during kexec_file_load() syscall" depends on KEXEC_FILE diff --git a/arch/x86/include/asm/crash_core.h b/arch/x86/include/asm/crash_core.h new file mode 100644 index 000000000000..5fc5e4f94521 --- /dev/null +++ b/arch/x86/include/asm/crash_core.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _X86_CRASH_CORE_H +#define _X86_CRASH_CORE_H + +/* 16M alignment for crash kernel regions */ +#define CRASH_ALIGN SZ_16M + +/* + * Keep the crash kernel below this limit. + * + * Earlier 32-bits kernels would limit the kernel to the low 512 MB range + * due to mapping restrictions. + * + * 64-bit kdump kernels need to be restricted to be under 64 TB, which is + * the upper limit of system RAM in 4-level paging mode. Since the kdump + * jump could be from 5-level paging to 4-level paging, the jump will fail if + * the kernel is put above 64 TB, and during the 1st kernel bootup there's + * no good way to detect the paging mode of the target kernel which will be + * loaded for dumping. + */ + +#ifdef CONFIG_X86_32 +# define CRASH_ADDR_LOW_MAX SZ_512M +# define CRASH_ADDR_HIGH_MAX SZ_512M +#else +# define CRASH_ADDR_LOW_MAX SZ_4G +# define CRASH_ADDR_HIGH_MAX SZ_64T +#endif + +# define DEFAULT_CRASH_KERNEL_LOW_SIZE crash_low_size_default() + +extern unsigned long crash_low_size_default(void); + +#endif /* _X86_CRASH_CORE_H */ diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 382c66d2cf71..559a5c4141db 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -474,152 +474,40 @@ static void __init memblock_x86_reserve_range_setup_data(void) /* * --------- Crashkernel reservation ------------------------------ */ - -/* 16M alignment for crash kernel regions */ -#define CRASH_ALIGN SZ_16M - -/* - * Keep the crash kernel below this limit. - * - * Earlier 32-bits kernels would limit the kernel to the low 512 MB range - * due to mapping restrictions. - * - * 64-bit kdump kernels need to be restricted to be under 64 TB, which is - * the upper limit of system RAM in 4-level paging mode. Since the kdump - * jump could be from 5-level paging to 4-level paging, the jump will fail if - * the kernel is put above 64 TB, and during the 1st kernel bootup there's - * no good way to detect the paging mode of the target kernel which will be - * loaded for dumping. - */ -#ifdef CONFIG_X86_32 -# define CRASH_ADDR_LOW_MAX SZ_512M -# define CRASH_ADDR_HIGH_MAX SZ_512M -#else -# define CRASH_ADDR_LOW_MAX SZ_4G -# define CRASH_ADDR_HIGH_MAX SZ_64T -#endif - -static int __init reserve_crashkernel_low(void) +unsigned long crash_low_size_default(void) { #ifdef CONFIG_X86_64 - unsigned long long base, low_base = 0, low_size = 0; - unsigned long low_mem_limit; - int ret; - - low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX); - - /* crashkernel=Y,low */ - ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base); - if (ret) { - /* - * two parts from kernel/dma/swiotlb.c: - * -swiotlb size: user-specified with swiotlb= or default. - * - * -swiotlb overflow buffer: now hardcoded to 32k. We round it - * to 8M for other buffers that may need to stay low too. Also - * make sure we allocate enough extra low memory so that we - * don't run out of DMA buffers for 32-bit devices. - */ - low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); - } else { - /* passed with crashkernel=0,low ? */ - if (!low_size) - return 0; - } - - low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX); - if (!low_base) { - pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", - (unsigned long)(low_size >> 20)); - return -ENOMEM; - } - - pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n", - (unsigned long)(low_size >> 20), - (unsigned long)(low_base >> 20), - (unsigned long)(low_mem_limit >> 20)); - - crashk_low_res.start = low_base; - crashk_low_res.end = low_base + low_size - 1; - insert_resource(&iomem_resource, &crashk_low_res); -#endif + return max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); +#else return 0; +#endif } -static void __init reserve_crashkernel(void) +static void __init arch_reserve_crashkernel(void) { - unsigned long long crash_size, crash_base, total_mem; + unsigned long long crash_base, crash_size, low_size = 0; + char *cmdline = boot_command_line; bool high = false; int ret; if (!IS_ENABLED(CONFIG_KEXEC_CORE)) return; - total_mem = memblock_phys_mem_size(); - - /* crashkernel=XM */ - ret = parse_crashkernel(boot_command_line, total_mem, - &crash_size, &crash_base, NULL, NULL); - if (ret != 0 || crash_size <= 0) { - /* crashkernel=X,high */ - ret = parse_crashkernel_high(boot_command_line, total_mem, - &crash_size, &crash_base); - if (ret != 0 || crash_size <= 0) - return; - high = true; - } + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), + &crash_size, &crash_base, + &low_size, &high); + if (ret) + return; if (xen_pv_domain()) { pr_info("Ignoring crashkernel for a Xen PV domain\n"); return; } - /* 0 means: find the address automatically */ - if (!crash_base) { - /* - * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, - * crashkernel=x,high reserves memory over 4G, also allocates - * 256M extra low memory for DMA buffers and swiotlb. - * But the extra memory is not required for all machines. - * So try low memory first and fall back to high memory - * unless "crashkernel=size[KMG],high" is specified. - */ - if (!high) - crash_base = memblock_phys_alloc_range(crash_size, - CRASH_ALIGN, CRASH_ALIGN, - CRASH_ADDR_LOW_MAX); - if (!crash_base) - crash_base = memblock_phys_alloc_range(crash_size, - CRASH_ALIGN, CRASH_ALIGN, - CRASH_ADDR_HIGH_MAX); - if (!crash_base) { - pr_info("crashkernel reservation failed - No suitable area found.\n"); - return; - } - } else { - unsigned long long start; - - start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base, - crash_base + crash_size); - if (start != crash_base) { - pr_info("crashkernel reservation failed - memory is in use.\n"); - return; - } - } - - if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) { - memblock_phys_free(crash_base, crash_size); - return; - } - - pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n", - (unsigned long)(crash_size >> 20), - (unsigned long)(crash_base >> 20), - (unsigned long)(total_mem >> 20)); + reserve_crashkernel_generic(cmdline, crash_size, crash_base, + low_size, high); - crashk_res.start = crash_base; - crashk_res.end = crash_base + crash_size - 1; - insert_resource(&iomem_resource, &crashk_res); + return; } static struct resource standard_io_resources[] = { @@ -1231,7 +1119,7 @@ void __init setup_arch(char **cmdline_p) * Reserve memory for crash kernel after SRAT is parsed so that it * won't consume hotpluggable memory. */ - reserve_crashkernel(); + arch_reserve_crashkernel(); memblock_find_dma_reserve();