From patchwork Thu Apr 7 12:03:18 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shannon Zhao X-Patchwork-Id: 8771861 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 9CD46C0553 for ; Thu, 7 Apr 2016 12:08:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8E78120251 for ; Thu, 7 Apr 2016 12:08:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 943212020F for ; Thu, 7 Apr 2016 12:08:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756305AbcDGMHw (ORCPT ); Thu, 7 Apr 2016 08:07:52 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:30292 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756300AbcDGMHt (ORCPT ); Thu, 7 Apr 2016 08:07:49 -0400 Received: from 172.24.1.60 (EHLO SZXEML424-HUB.china.huawei.com) ([172.24.1.60]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id BZL25429; Thu, 07 Apr 2016 20:04:15 +0800 (CST) Received: from HGHY1Z002260041.china.huawei.com (10.177.16.142) by SZXEML424-HUB.china.huawei.com (10.82.67.153) with Microsoft SMTP Server id 14.3.235.1; Thu, 7 Apr 2016 20:04:04 +0800 From: Shannon Zhao To: , CC: , , , , , , , , , , "Rafael J. Wysocki" , "Len Brown" , "open list:ACPI" Subject: [PATCH v11 01/17] Xen: ACPI: Hide UART used by Xen Date: Thu, 7 Apr 2016 20:03:18 +0800 Message-ID: <1460030614-16112-2-git-send-email-zhaoshenglong@huawei.com> X-Mailer: git-send-email 1.9.0.msysgit.0 In-Reply-To: <1460030614-16112-1-git-send-email-zhaoshenglong@huawei.com> References: <1460030614-16112-1-git-send-email-zhaoshenglong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.177.16.142] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090205.57064CC4.0070, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 1cb5d3b2a60d36f034708b040098c776 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Shannon Zhao ACPI 6.0 introduces a new table STAO to list the devices which are used by Xen and can't be used by Dom0. On Xen virtual platforms, the physical UART is used by Xen. So here it hides UART from Dom0. CC: "Rafael J. Wysocki" (supporter:ACPI) CC: Len Brown (supporter:ACPI) CC: linux-acpi@vger.kernel.org (open list:ACPI) Signed-off-by: Shannon Zhao Acked-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 5f28cf7..cfc73fe 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -46,6 +46,13 @@ DEFINE_MUTEX(acpi_device_lock); LIST_HEAD(acpi_wakeup_device_list); static DEFINE_MUTEX(acpi_hp_context_lock); +/* + * The UART device described by the SPCR table is the only object which needs + * special-casing. Everything else is covered by ACPI namespace paths in STAO + * table. + */ +static u64 spcr_uart_addr; + struct acpi_dep_data { struct list_head node; acpi_handle master; @@ -1453,6 +1460,41 @@ static int acpi_add_single_object(struct acpi_device **child, return 0; } +static acpi_status acpi_get_resource_memory(struct acpi_resource *ares, + void *context) +{ + struct resource *res = context; + + if (acpi_dev_resource_memory(ares, res)) + return AE_CTRL_TERMINATE; + + return AE_OK; +} + +static bool acpi_device_should_be_hidden(acpi_handle handle) +{ + acpi_status status; + struct resource res; + + /* Check if it should ignore the UART device */ + if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS))) + return false; + + /* + * The UART device described in SPCR table is assumed to have only one + * memory resource present. So we only look for the first one here. + */ + status = acpi_walk_resources(handle, METHOD_NAME__CRS, + acpi_get_resource_memory, &res); + if (ACPI_FAILURE(status) || res.start != spcr_uart_addr) + return false; + + acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n", + &res.start); + + return true; +} + static int acpi_bus_type_and_status(acpi_handle handle, int *type, unsigned long long *sta) { @@ -1466,6 +1508,9 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type, switch (acpi_type) { case ACPI_TYPE_ANY: /* for ACPI_ROOT_OBJECT */ case ACPI_TYPE_DEVICE: + if (acpi_device_should_be_hidden(handle)) + return -ENODEV; + *type = ACPI_BUS_TYPE_DEVICE; status = acpi_bus_get_status_handle(handle, sta); if (ACPI_FAILURE(status)) @@ -1916,9 +1961,24 @@ static int acpi_bus_scan_fixed(void) return result < 0 ? result : 0; } +static void __init acpi_get_spcr_uart_addr(void) +{ + acpi_status status; + struct acpi_table_spcr *spcr_ptr; + + status = acpi_get_table(ACPI_SIG_SPCR, 0, + (struct acpi_table_header **)&spcr_ptr); + if (ACPI_SUCCESS(status)) + spcr_uart_addr = spcr_ptr->serial_port.address; + else + printk(KERN_WARNING PREFIX "STAO table present, but SPCR is missing\n"); +} + int __init acpi_scan_init(void) { int result; + acpi_status status; + struct acpi_table_stao *stao_ptr; acpi_pci_root_init(); acpi_pci_link_init(); @@ -1934,6 +1994,20 @@ int __init acpi_scan_init(void) acpi_scan_add_handler(&generic_device_handler); + /* + * If there is STAO table, check whether it needs to ignore the UART + * device in SPCR table. + */ + status = acpi_get_table(ACPI_SIG_STAO, 0, + (struct acpi_table_header **)&stao_ptr); + if (ACPI_SUCCESS(status)) { + if (stao_ptr->header.length > sizeof(struct acpi_table_stao)) + printk(KERN_INFO PREFIX "STAO Name List not yet supported."); + + if (stao_ptr->ignore_uart) + acpi_get_spcr_uart_addr(); + } + mutex_lock(&acpi_scan_lock); /* * Enumerate devices in the ACPI namespace.