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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3FC4C433E1 for ; Fri, 19 Jun 2020 15:56:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C11CA20809 for ; Fri, 19 Jun 2020 15:56:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592582205; bh=0DE62OxpKPeTWcX/ynCTAsqhjaPry1kDxHTLBwogLd8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vCIsH3TbhVquH6CdAcU9FRdN6hKMKdtSpHWTXSvx/Rh864ziCj6wdJciBQFL1IQZu baAZVl1sIvuvnPOxv5VGg19gNYC1EIxvoUBwQzCxFWbOrtB1RLHMxwSw6VoykBrrJu CUzPEKHXvnl7OFwu/3mjLB6vvGDMmVx9M6JJrq4U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388720AbgFSP4o (ORCPT ); Fri, 19 Jun 2020 11:56:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:52228 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390610AbgFSPUy (ORCPT ); Fri, 19 Jun 2020 11:20:54 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D639420B80; Fri, 19 Jun 2020 15:20:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592580053; bh=0DE62OxpKPeTWcX/ynCTAsqhjaPry1kDxHTLBwogLd8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K8AZLGn6AZMM/fP/CU7PWZgAhLrUOU/70oEvrS2VQCx/j097M1FCdh13DihbIvV7N tNsmJFPONh4Ev6YlfidZOwVWGozQ6Kn7JCd6/J8b15ojwmaznRBT00r9s/bETcc4kR MjvjZkVXEBf+mBbb5LdRGppukl2Yn8PXZJHhGDLw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Juxin Gao , Tiezhu Yang , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.7 104/376] MIPS: Make sparse_init() using top-down allocation Date: Fri, 19 Jun 2020 16:30:22 +0200 Message-Id: <20200619141715.270879870@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141710.350494719@linuxfoundation.org> References: <20200619141710.350494719@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tiezhu Yang [ Upstream commit 269b3a9ac538c4ae87f84be640b9fa89914a2489 ] In the current code, if CONFIG_SWIOTLB is set, when failed to get IO TLB memory from the low pages by plat_swiotlb_setup(), it may lead to the boot process failed with kernel panic. (1) On the Loongson and SiByte platform arch/mips/loongson64/dma.c arch/mips/sibyte/common/dma.c void __init plat_swiotlb_setup(void) { swiotlb_init(1); } kernel/dma/swiotlb.c void __init swiotlb_init(int verbose) { ... vstart = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE); if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose)) return; ... pr_warn("Cannot allocate buffer"); no_iotlb_memory = true; } phys_addr_t swiotlb_tbl_map_single() { ... if (no_iotlb_memory) panic("Can not allocate SWIOTLB buffer earlier ..."); ... } (2) On the Cavium OCTEON platform arch/mips/cavium-octeon/dma-octeon.c void __init plat_swiotlb_setup(void) { ... octeon_swiotlb = memblock_alloc_low(swiotlbsize, PAGE_SIZE); if (!octeon_swiotlb) panic("%s: Failed to allocate %zu bytes align=%lx\n", __func__, swiotlbsize, PAGE_SIZE); ... } Because IO_TLB_DEFAULT_SIZE is 64M, if the rest size of low memory is less than 64M when call plat_swiotlb_setup(), we can easily reproduce the panic case. In order to reduce the possibility of kernel panic when failed to get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate low memory as small as possible before plat_swiotlb_setup(), so make sparse_init() using top-down allocation. Reported-by: Juxin Gao Co-developed-by: Juxin Gao Signed-off-by: Juxin Gao Signed-off-by: Tiezhu Yang Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/kernel/setup.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 10bef8f78e7c..573509e0f2d4 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -702,7 +702,17 @@ static void __init arch_mem_init(char **cmdline_p) memblock_reserve(crashk_res.start, resource_size(&crashk_res)); #endif device_tree_init(); + + /* + * In order to reduce the possibility of kernel panic when failed to + * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate + * low memory as small as possible before plat_swiotlb_setup(), so + * make sparse_init() using top-down allocation. + */ + memblock_set_bottom_up(false); sparse_init(); + memblock_set_bottom_up(true); + plat_swiotlb_setup(); dma_contiguous_reserve(PFN_PHYS(max_low_pfn)); -- 2.25.1