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=unavailable 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 268D6C2BA83 for ; Fri, 14 Feb 2020 17:03:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F14C920656 for ; Fri, 14 Feb 2020 17:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581699838; bh=NroTEEz88OFI1ey2Ae6osJV4lvm97R1EcRqCkBVhUgg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NbVMmyAxWHezjMFV/PfQNU8LjVna/sC/IuB3q5OidwxW3dzEqrp1jqkusxhuIOxDv ppY58RdPiM9fsJ0qHqoivvAR5wlCw7QQvNh+MRcEIMWg4uIqHs4CYZuBQFEJ073Ua6 GYr6LSR7RXkpuZUQnDAYYQdrpLmkp2WGao+7H+M0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394460AbgBNRD5 (ORCPT ); Fri, 14 Feb 2020 12:03:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:46218 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392500AbgBNQPp (ORCPT ); Fri, 14 Feb 2020 11:15:45 -0500 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 00A75246E6; Fri, 14 Feb 2020 16:15:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581696944; bh=NroTEEz88OFI1ey2Ae6osJV4lvm97R1EcRqCkBVhUgg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2CEkLWYjd5V/rag2iGhOh7kdYAB5UfN4oW1z9nHIqWF4SCnMKhUfVW+JVPMj8Dg4A S+NCvkUols+CsVA7Pdf7/0uKgAZ1ZWpaqnK7Gno/IwoUBWN26QID9iVSvsRr4ia09+ oYzi4FID7KbDqyrS4NRxWjhqH3RRcZhGEYnkgd60= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hanjun Guo , Pankaj Bansal , Lorenzo Pieralisi , Will Deacon , Sudeep Holla , Catalin Marinas , Robin Murphy , Sasha Levin , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 186/252] ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map() Date: Fri, 14 Feb 2020 11:10:41 -0500 Message-Id: <20200214161147.15842-186-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214161147.15842-1-sashal@kernel.org> References: <20200214161147.15842-1-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: Hanjun Guo [ Upstream commit 3c23b83a88d00383e1d498cfa515249aa2fe0238 ] The IORT specification [0] (Section 3, table 4, page 9) defines the 'Number of IDs' as 'The number of IDs in the range minus one'. However, the IORT ID mapping function iort_id_map() treats the 'Number of IDs' field as if it were the full IDs mapping count, with the following check in place to detect out of boundary input IDs: InputID >= Input base + Number of IDs This check is flawed in that it considers the 'Number of IDs' field as the full number of IDs mapping and disregards the 'minus one' from the IDs count. The correct check in iort_id_map() should be implemented as: InputID > Input base + Number of IDs this implements the specification correctly but unfortunately it breaks existing firmwares that erroneously set the 'Number of IDs' as the full IDs mapping count rather than IDs mapping count minus one. e.g. PCI hostbridge mapping entry 1: Input base: 0x1000 ID Count: 0x100 Output base: 0x1000 Output reference: 0xC4 //ITS reference PCI hostbridge mapping entry 2: Input base: 0x1100 ID Count: 0x100 Output base: 0x2000 Output reference: 0xD4 //ITS reference Two mapping entries which the second entry's Input base = the first entry's Input base + ID count, so for InputID 0x1100 and with the correct InputID check in place in iort_id_map() the kernel would map the InputID to ITS 0xC4 not 0xD4 as it would be expected. Therefore, to keep supporting existing flawed firmwares, introduce a workaround that instructs the kernel to use the old InputID range check logic in iort_id_map(), so that we can support both firmwares written with the flawed 'Number of IDs' logic and the correct one as defined in the specifications. [0]: http://infocenter.arm.com/help/topic/com.arm.doc.den0049d/DEN0049D_IO_Remapping_Table.pdf Reported-by: Pankaj Bansal Link: https://lore.kernel.org/linux-acpi/20191215203303.29811-1-pankaj.bansal@nxp.com/ Signed-off-by: Hanjun Guo Signed-off-by: Lorenzo Pieralisi Cc: Pankaj Bansal Cc: Will Deacon Cc: Sudeep Holla Cc: Catalin Marinas Cc: Robin Murphy Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/acpi/arm64/iort.c | 57 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 55 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index e11b5da6f828f..7d86468300b78 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -306,6 +306,59 @@ static acpi_status iort_match_node_callback(struct acpi_iort_node *node, return status; } +struct iort_workaround_oem_info { + char oem_id[ACPI_OEM_ID_SIZE + 1]; + char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1]; + u32 oem_revision; +}; + +static bool apply_id_count_workaround; + +static struct iort_workaround_oem_info wa_info[] __initdata = { + { + .oem_id = "HISI ", + .oem_table_id = "HIP07 ", + .oem_revision = 0, + }, { + .oem_id = "HISI ", + .oem_table_id = "HIP08 ", + .oem_revision = 0, + } +}; + +static void __init +iort_check_id_count_workaround(struct acpi_table_header *tbl) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(wa_info); i++) { + if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) && + !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) && + wa_info[i].oem_revision == tbl->oem_revision) { + apply_id_count_workaround = true; + pr_warn(FW_BUG "ID count for ID mapping entry is wrong, applying workaround\n"); + break; + } + } +} + +static inline u32 iort_get_map_max(struct acpi_iort_id_mapping *map) +{ + u32 map_max = map->input_base + map->id_count; + + /* + * The IORT specification revision D (Section 3, table 4, page 9) says + * Number of IDs = The number of IDs in the range minus one, but the + * IORT code ignored the "minus one", and some firmware did that too, + * so apply a workaround here to keep compatible with both the spec + * compliant and non-spec compliant firmwares. + */ + if (apply_id_count_workaround) + map_max--; + + return map_max; +} + static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out) { @@ -322,8 +375,7 @@ static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, return -ENXIO; } - if (rid_in < map->input_base || - (rid_in >= map->input_base + map->id_count)) + if (rid_in < map->input_base || rid_in > iort_get_map_max(map)) return -ENXIO; *rid_out = map->output_base + (rid_in - map->input_base); @@ -1542,5 +1594,6 @@ void __init acpi_iort_init(void) return; } + iort_check_id_count_workaround(iort_table); iort_init_platform_devices(); } -- 2.20.1