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 6136CC433F5 for ; Wed, 11 May 2022 12:43:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242676AbiEKMnj (ORCPT ); Wed, 11 May 2022 08:43:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235845AbiEKMne (ORCPT ); Wed, 11 May 2022 08:43:34 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 258EA3F311 for ; Wed, 11 May 2022 05:43:31 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0VCwOcAr_1652273005; Received: from B-LB6YLVDL-0141.local(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VCwOcAr_1652273005) by smtp.aliyun-inc.com(127.0.0.1); Wed, 11 May 2022 20:43:26 +0800 Subject: Re: [PATCH] RISC-V: Remove IORESOURCE_BUSY flag for no-map reserved memory From: Xianting Tian To: David Hildenbrand , paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, akpm@linux-foundation.org, anup@brainfault.org, wangkefeng.wang@huawei.com, rppt@kernel.org, alex@ghiti.fr, twd2.me@gmail.com, seanjc@google.com, petr.pavlu@suse.com, atishp@rivosinc.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, guoren@kernel.org, jianghuaming.jhm@alibaba-inc.com, Nick Kossifidis References: <20220511112413.559734-1-xianting.tian@linux.alibaba.com> <4407c84b-a64f-51b0-fa96-388aaf3b3e35@redhat.com> Message-ID: Date: Wed, 11 May 2022 20:43:25 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022/5/11 下午8:37, Xianting Tian 写道: > > 在 2022/5/11 下午8:27, David Hildenbrand 写道: >> On 11.05.22 13:24, Xianting Tian wrote: >>> Commit 00ab027a3b82 ("RISC-V: Add kernel image sections to the >>> resource tree") >>> added IORESOURCE_BUSY flag for no-map reserved memory, this casued >>> devm_ioremap_resource() failed for the no-map reserved memory in >>> subsequent >>> operations of related driver, so remove the IORESOURCE_BUSY flag. >>> >>> The code to reproduce the issue, >>> dts: >>>     mem0: memory@a0000000 { >>>                  reg = <0x0 0xa0000000 0 0x1000000>; >>>                  no-map; >>>          }; >>> >>>     &test { >>>         status = "okay"; >>>         memory-region = <&mem0>; >>>     }; >>> >>> code: >>>     np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0); >>>     ret = of_address_to_resource(np, 0, &r); >>>     base = devm_ioremap_resource(&pdev->dev, &r); >>>     // base = -EBUSY >>> >>> Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the >>> resource tree") >>> Reported-by: Huaming Jiang >>> Reviewed-by: Guo Ren >>> CC: Nick Kossifidis >>> Signed-off-by: Xianting Tian >>> --- >>>   arch/riscv/kernel/setup.c | 2 +- >>>   1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c >>> index 834eb652a7b9..71f2966b1474 100644 >>> --- a/arch/riscv/kernel/setup.c >>> +++ b/arch/riscv/kernel/setup.c >>> @@ -214,7 +214,7 @@ static void __init init_resources(void) >>>             if (unlikely(memblock_is_nomap(region))) { >>>               res->name = "Reserved"; >>> -            res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; >>> +            res->flags = IORESOURCE_MEM; >>>           } else { >>>               res->name = "System RAM"; >>>               res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; >> I assume the "Reserved" part is essentially unused by the kernel >> correct? > > I think we may use it, actually we found the issue in our product > after merged kdump functionality. > > Actually, the code didn't add IORESOURCE_BUSY for no-map reserved > memory before 00ab027a3b82 merged,  so it is a typo for commit > 00ab027a3b82 to add IORESOURCE_BUSY? This is arm64 code, which doesn't add IORESOURCE_BUSY for no-map reserved memory, arch/arm64/kernel/setup.c         for_each_mem_region(region) {                 res = &standard_resources[i++];                 if (memblock_is_nomap(region)) {                         res->name  = "reserved";                         res->flags = IORESOURCE_MEM;                         res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));                         res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1; > >>