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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 DD4C3C433E0 for ; Mon, 8 Jun 2020 23:48:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B958A204EF for ; Mon, 8 Jun 2020 23:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591660107; bh=2qLyoYM5uT2rMeb6vdKw9v73BZGzqv06q+5YAIglqCc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=E12QsiuoELUDWFPkL+jU5bB0VXzkr5LQZBCipvh6TyJAd/ROQwMcLvSu5Pspbn+GA q1d48zCAEUQVaww6+iOaKveK+uzkZKkSnuhe1+D48UHrep5yEf7sTW7JDpbkHp4cPt 3nKu8Pu2PbXXKrM+35vW7kxDWQeVyLemmY2Hr18M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732506AbgFHXs1 (ORCPT ); Mon, 8 Jun 2020 19:48:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:52506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731851AbgFHXZq (ORCPT ); Mon, 8 Jun 2020 19:25:46 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 86CA22068D; Mon, 8 Jun 2020 23:25:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658746; bh=2qLyoYM5uT2rMeb6vdKw9v73BZGzqv06q+5YAIglqCc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kUGKKoA0uKeb49hOEdk5MkM+APjPBudSBpJZKeC8SZAjOMbxyjeeow7DMmG8JdrtM 0cSMAa5jJZZu0HHIXMEoadVKXuUWyN/rycntl+l2U5+0YC5lYSr/sDzI+QAGCZ5Zbo 46XrI5fLpV1jSpWELXAbebkKEktz9nMCQzhRcBFI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tiezhu Yang , Juxin Gao , Thomas Bogendoerfer , Sasha Levin , linux-mips@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 32/72] MIPS: Make sparse_init() using top-down allocation Date: Mon, 8 Jun 2020 19:24:20 -0400 Message-Id: <20200608232500.3369581-32-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608232500.3369581-1-sashal@kernel.org> References: <20200608232500.3369581-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 05ed4ed411c7..abd7ee9e90ab 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -911,7 +911,17 @@ static void __init arch_mem_init(char **cmdline_p) BOOTMEM_DEFAULT); #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