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 B12BDC433FE for ; Fri, 11 Feb 2022 10:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348908AbiBKKbT (ORCPT ); Fri, 11 Feb 2022 05:31:19 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:56044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348914AbiBKKbR (ORCPT ); Fri, 11 Feb 2022 05:31:17 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 69BDCEB4 for ; Fri, 11 Feb 2022 02:31:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644575474; 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: in-reply-to:in-reply-to:references:references; bh=iBor/4ctD9Su3Z9/rV8GOGhFf5h1VX6eZd38snr721I=; b=QQHs2iJQkmD+McjJi9afJ46cH62BSn7bIj23Gm8Xv/mvzsXrbKx6Cte2b174sgUGsDaeiM hQe8V4c4Sn3laN8Gt6CeKxMORrJgseSigTU3sczcWxChZX8KORfe6ebnj41PX7oO5TQYA8 HAzXvnBP4I3myy8cZcYGYm/7gFIdgpk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-37-VbLescsqPOa17IZbRMefJg-1; Fri, 11 Feb 2022 05:31:11 -0500 X-MC-Unique: VbLescsqPOa17IZbRMefJg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9D5C518982B7; Fri, 11 Feb 2022 10:30:39 +0000 (UTC) Received: from localhost (ovpn-13-96.pek2.redhat.com [10.72.13.96]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AC3AD7D728; Fri, 11 Feb 2022 10:30:37 +0000 (UTC) Date: Fri, 11 Feb 2022 18:30:34 +0800 From: Baoquan He To: Zhen Lei Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , linux-kernel@vger.kernel.org, Dave Young , Vivek Goyal , Eric Biederman , kexec@lists.infradead.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, Rob Herring , Frank Rowand , devicetree@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , John Donnelly , Dave Kleikamp Subject: Re: [PATCH v20 3/5] arm64: kdump: reimplement crashkernel=X Message-ID: References: <20220124084708.683-1-thunder.leizhen@huawei.com> <20220124084708.683-4-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220124084708.683-4-thunder.leizhen@huawei.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/24/22 at 04:47pm, Zhen Lei wrote: > From: Chen Zhou ...... > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 6c653a2c7cff052..a5d43feac0d7d96 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -71,6 +71,30 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init; > #define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit > #define CRASH_ADDR_HIGH_MAX MEMBLOCK_ALLOC_ACCESSIBLE > > +static int __init reserve_crashkernel_low(unsigned long long low_size) > +{ > + unsigned long long low_base; > + > + /* 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 allocate crashkernel low memory (size:0x%llx).\n", low_size); > + return -ENOMEM; > + } > + > + pr_info("crashkernel low memory reserved: 0x%llx - 0x%llx (%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 > * > @@ -81,29 +105,62 @@ 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_low_size = SZ_256M; > unsigned long long crash_max = CRASH_ADDR_LOW_MAX; > int ret; > + bool fixed_base; > + char *cmdline = boot_command_line; > > - 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) > - return; > + if (ret || !crash_size) { > + unsigned long long low_size; > > + /* crashkernel=X,high */ > + ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base); > + if (ret || !crash_size) > + return; > + > + /* crashkernel=X,low */ > + ret = parse_crashkernel_low(cmdline, 0, &low_size, &crash_base); > + if (!ret) > + crash_low_size = low_size; Here, the error case is not checked and handled. But it still gets expeced result which is the default SZ_256M. Is this designed on purpose? > + > + crash_max = CRASH_ADDR_HIGH_MAX; > + } > + > + fixed_base = !!crash_base; > crash_size = PAGE_ALIGN(crash_size); > > /* User specifies base address explicitly. */ > if (crash_base) > crash_max = crash_base + crash_size; > > +retry: > crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, > crash_base, crash_max); > if (!crash_base) { > + /* > + * Attempt to fully allocate low memory failed, fall back > + * to high memory, the minimum required low memory will be > + * reserved later. > + */ > + if (!fixed_base && (crash_max == CRASH_ADDR_LOW_MAX)) { > + crash_max = CRASH_ADDR_HIGH_MAX; > + goto retry; > + } > + > pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > crash_size); > return; > } > > + if (crash_base >= SZ_4G && 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); > > @@ -112,6 +169,9 @@ 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 >