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 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 5E51AC76195 for ; Tue, 21 Mar 2023 01:43:27 +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:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=l/4VKXZ4Q8BmA8xJO+eH7Fnx3kwVBb+1fVrGU5+/sEU=; b=Tgh5paK7DswtsTFqip1OCdc0ns EQ5cA+h08JnkqzhrACW/FGPeLa1NE43InYJg/nSkCRBven35A4alsL6maCcSz1yuFXehtII1kGuHD v/rN67H7/uYfv/R6GVO851OA+3Qvw94znNFDv0MF48oxNKV8EKivlhHZmKIh88zGBGAKnGe8Gcich SehKF/oE+TRT1AlWIc+ObdAOgl1734V4l/1EyKTsUJmEhQTmj0YiL85RtmVtPmZVILQdo/39C+P5H hPXDkboRIijsb6sgn4/rvo3euuvAwjj4JLIdqN1kEDaSi5N6o/jSsHYVhlumz8p9mwuFkwTfjRFWn KQlZGf8Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1peR1w-00AxX6-27; Tue, 21 Mar 2023 01:43:16 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1peR1p-00AxVg-21; Tue, 21 Mar 2023 01:43:12 +0000 Received: from dggpemm500006.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4PgZ6J69FJznYwQ; Tue, 21 Mar 2023 09:39:52 +0800 (CST) Received: from [10.174.178.55] (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 15.1.2507.21; Tue, 21 Mar 2023 09:42:57 +0800 Subject: Re: [PATCH -next 1/2] riscv: kdump: Implement crashkernel=X,[high,low] To: Chen Jiahao , , , , , , , , , , CC: , , , References: <20230320204244.1637821-1-chenjiahao16@huawei.com> <20230320204244.1637821-2-chenjiahao16@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: Date: Tue, 21 Mar 2023 09:42:56 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20230320204244.1637821-2-chenjiahao16@huawei.com> Content-Language: en-US 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230320_184310_004723_38A49AB9 X-CRM114-Status: GOOD ( 26.52 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On 2023/3/21 4:42, Chen Jiahao wrote: > On riscv, the current crash kernel allocation logic is trying to > allocate within 32bit addressible memory region by default, if > failed, try to allocate without 4G restriction. > > In need of saving DMA zone memory while allocating a relatively large > crash kernel region, allocating the reserved memory top down in > high memory, without overlapping the DMA zone, is a mature solution. > Here introduce the parameter option crashkernel=X,[high,low]. > > We can reserve the crash kernel from high memory above DMA zone range > by explicitly passing "crashkernel=X,high"; or reserve a memory range > below 4G with "crashkernel=X,low". > > Signed-off-by: Chen Jiahao > --- > arch/riscv/kernel/setup.c | 5 ++++ > arch/riscv/mm/init.c | 56 ++++++++++++++++++++++++++++++++++++--- > 2 files changed, 58 insertions(+), 3 deletions(-) > > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > index 376d2827e736..d867b1535da4 100644 > --- a/arch/riscv/kernel/setup.c > +++ b/arch/riscv/kernel/setup.c > @@ -176,6 +176,11 @@ static void __init init_resources(void) > if (ret < 0) > goto error; > } > + if (crashk_low_res.start != crashk_low_res.end) { > + ret = add_resource(&iomem_resource, &crashk_low_res); > + if (ret < 0) > + goto error; > + } > #endif > > #ifdef CONFIG_CRASH_DUMP > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 478d6763a01a..5def2174b243 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -1152,6 +1152,28 @@ static inline void setup_vm_final(void) > } > #endif /* CONFIG_MMU */ > > +/* Reserve 128M low memory by default for swiotlb buffer */ > +#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20) > + > +static int __init reserve_crashkernel_low(unsigned long long low_size) > +{ > + unsigned long long low_base; > + > + low_base = memblock_phys_alloc_range(low_size, PMD_SIZE, 0, dma32_phys_limit); > + 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", For unsigned long long, 08 --> 016. > + low_base, low_base + low_size, low_size >> 20); > + > + crashk_low_res.start = low_base; > + crashk_low_res.end = low_base + low_size - 1; > + > + return 0; > +} > + > /* > * reserve_crashkernel() - reserves memory for crash kernel > * > @@ -1163,6 +1185,7 @@ static void __init reserve_crashkernel(void) > { > unsigned long long crash_base = 0; > unsigned long long crash_size = 0; > + unsigned long long crash_low_size = 0; > unsigned long search_start = memblock_start_of_DRAM(); > unsigned long search_end = memblock_end_of_DRAM(); > > @@ -1182,8 +1205,26 @@ static void __init reserve_crashkernel(void) > > ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), > &crash_size, &crash_base); > - if (ret || !crash_size) > + if (ret == -ENOENT) { > + ret = parse_crashkernel_high(boot_command_line, 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(boot_command_line, 0, &crash_low_size, &crash_base); > + if (ret == -ENOENT) > + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; > + else if (ret) > + return; > + > + search_start = dma32_phys_limit; > + } else if (ret || !crash_size) { > + /* Invalid argument value specified */ > return; > + } > > crash_size = PAGE_ALIGN(crash_size); > > @@ -1201,16 +1242,25 @@ static void __init reserve_crashkernel(void) > */ > crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE, > search_start, > - min(search_end, (unsigned long) SZ_4G)); > + min(search_end, (unsigned long) dma32_phys_limit)); > if (crash_base == 0) { > /* Try again without restricting region to 32bit addressible memory */ > crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE, > - search_start, search_end); > + search_start, search_end); > if (crash_base == 0) { > pr_warn("crashkernel: couldn't allocate %lldKB\n", > crash_size >> 10); > return; > } > + > + if (!crash_low_size) > + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; > + } > + > + if ((crash_base > dma32_phys_limit - crash_low_size) && > + 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", > -- Regards, Zhen Lei _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv