From patchwork Tue Jul 25 21:44:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Jiahao X-Patchwork-Id: 13326465 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 BDF54C001DF for ; Tue, 25 Jul 2023 13:45:37 +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=Q8SOo/g/IfZZNboGj2nrl273SwxhH6Q+vxQ8OhdkPSU=; b=qldEYycM0PxnNk P2kP1ljvCb4k7ec+yfet3JQHw+R5hbhXMxvo2OMaviLIUCwuCzplH8pzyeUnecxt2CWFndOTRipJO /59YuGBmm0DBbZLxZr1bNASPBVXg7lNDIgjedjFotN2uymY0gPJxWBu/rr0oOJgcJQWREc6qQWlkm F29Dwp4YkFODQ/c2I9KQ4wUBIl1wfCbX06zAMjPG56IOg0f+8QRb94/r66K/3W3t1p1NskWMLC8/7 Nu1VAbEA+fzNxbg63Td2hBWWhDgSCB2NeDGVvs//5WX4jBipW7O2niFHzzVeNJtk9f1XNvRO2hedQ Vkq8rw5KjmZh+3IPaeAw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qOILv-007fvS-2D; Tue, 25 Jul 2023 13:45:27 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qOILq-007fsI-2o; Tue, 25 Jul 2023 13:45:25 +0000 Received: from dggpemm500016.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4R9JCD6fF0zVjqj; Tue, 25 Jul 2023 21:43:36 +0800 (CST) Received: from huawei.com (10.67.174.205) by dggpemm500016.china.huawei.com (7.185.36.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Tue, 25 Jul 2023 21:45:09 +0800 From: Chen Jiahao To: , , , , , , , , , , , , , , , CC: Subject: [PATCH -next v8 1/2] riscv: kdump: Implement crashkernel=X,[high,low] Date: Tue, 25 Jul 2023 21:44:11 +0000 Message-ID: <20230725214413.2488159-2-chenjiahao16@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230725214413.2488159-1-chenjiahao16@huawei.com> References: <20230725214413.2488159-1-chenjiahao16@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.205] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpemm500016.china.huawei.com (7.185.36.25) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230725_064523_326204_3E7534D2 X-CRM114-Status: GOOD ( 18.83 ) 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: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 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]. One 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 Acked-by: Guo Ren --- arch/riscv/kernel/setup.c | 5 +++ arch/riscv/mm/init.c | 93 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 91 insertions(+), 7 deletions(-) diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 971fe776e2f8..376f5d49ce85 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -178,6 +178,11 @@ 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 9ce504737d18..156e09a1ceee 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1297,6 +1297,28 @@ 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%016llx - 0x%016llx (%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; + + return 0; +} + /* * reserve_crashkernel() - reserves memory for crash kernel * @@ -1308,8 +1330,12 @@ 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(); + unsigned long search_end = (unsigned long)dma32_phys_limit; + char *cmdline = boot_command_line; + bool fixed_base = false; + bool high = false; int ret = 0; @@ -1325,14 +1351,36 @@ static void __init reserve_crashkernel(void) return; } - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), &crash_size, &crash_base); - if (ret || !crash_size) + if (ret == -ENOENT) { + /* Fallback to crashkernel=X,[high,low] */ + ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base); + if (ret || !crash_size) + return; + + /* + * crashkernel=Y,low is valid only when crashkernel=X,high + * is passed. + */ + ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); + if (ret == -ENOENT) + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; + else if (ret) + return; + + search_start = (unsigned long)dma32_phys_limit; + search_end = memblock_end_of_DRAM(); + high = true; + } else if (ret || !crash_size) { + /* Invalid argument value specified */ return; + } crash_size = PAGE_ALIGN(crash_size); if (crash_base) { + fixed_base = true; search_start = crash_base; search_end = crash_base + crash_size; } @@ -1345,12 +1393,37 @@ static void __init reserve_crashkernel(void) * swiotlb can work on the crash kernel. */ crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE, - search_start, - min(search_end, (unsigned long)(SZ_4G - 1))); + search_start, search_end); if (crash_base == 0) { - /* Try again without restricting region to 32bit addressible memory */ + /* + * For crashkernel=size[KMG]@offset[KMG], print out failure + * message if can't reserve the specified region. + */ + if (fixed_base) { + pr_warn("crashkernel: allocating failed with given size@offset\n"); + return; + } + + if (high) { + /* + * For crashkernel=size[KMG],high, if the first attempt was + * for high memory, fall back to low memory. + */ + search_start = memblock_start_of_DRAM(); + search_end = (unsigned long)dma32_phys_limit; + } else { + /* + * For crashkernel=size[KMG], if the first attempt was for + * low memory, fall back to high memory, the minimum required + * low memory will be reserved later. + */ + search_start = (unsigned long)dma32_phys_limit; + search_end = memblock_end_of_DRAM(); + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; + } + 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); @@ -1358,6 +1431,12 @@ static void __init reserve_crashkernel(void) } } + if ((crash_base >= dma32_phys_limit) && 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);