From patchwork Fri Feb 5 03:05:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shannon Zhao X-Patchwork-Id: 8231031 Return-Path: X-Original-To: patchwork-linux-arm@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 074E9BEEE5 for ; Fri, 5 Feb 2016 03:18:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2387320397 for ; Fri, 5 Feb 2016 03:18:26 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 350BC20357 for ; Fri, 5 Feb 2016 03:18:25 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aRWt9-0000Cg-Vk; Fri, 05 Feb 2016 03:16:52 +0000 Received: from szxga01-in.huawei.com ([58.251.152.64]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aRWob-0002KW-0u for linux-arm-kernel@lists.infradead.org; Fri, 05 Feb 2016 03:13:11 +0000 Received: from 172.24.1.51 (EHLO SZXEML424-HUB.china.huawei.com) ([172.24.1.51]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DEF07688; Fri, 05 Feb 2016 11:07:15 +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; Fri, 5 Feb 2016 11:07:03 +0800 From: Shannon Zhao To: , , , Subject: [PATCH v4 01/17] Xen: ACPI: Hide UART used by Xen Date: Fri, 5 Feb 2016 11:05:36 +0800 Message-ID: <1454641552-12576-2-git-send-email-zhaoshenglong@huawei.com> X-Mailer: git-send-email 1.9.0.msysgit.0 In-Reply-To: <1454641552-12576-1-git-send-email-zhaoshenglong@huawei.com> References: <1454641552-12576-1-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=0001.0A020201.56B411E4.0020, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 4b027efd033464f2a7a5ede24456dc6f X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160204_191210_474820_7B063E03 X-CRM114-Status: GOOD ( 13.03 ) X-Spam-Score: -4.7 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, linux-efi@vger.kernel.org, ian.campbell@citrix.com, "Rafael J. Wysocki" , catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, xen-devel@lists.xen.org, julien.grall@citrix.com, "open list:ACPI" , shannon.zhao@linaro.org, peter.huangpeng@huawei.com, Len Brown Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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. Signed-off-by: Shannon Zhao Reviewed-by: Stefano Stabellini --- CC: "Rafael J. Wysocki" (supporter:ACPI) CC: Len Brown (supporter:ACPI) CC: linux-acpi@vger.kernel.org (open list:ACPI) --- drivers/acpi/bus.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index 891c42d..5b5433d 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -46,6 +46,7 @@ ACPI_MODULE_NAME("bus"); struct acpi_device *acpi_root; struct proc_dir_entry *acpi_root_dir; EXPORT_SYMBOL(acpi_root_dir); +static u64 spcr_uart_addr; #ifdef CONFIG_X86 #ifdef CONFIG_ACPI_CUSTOM_DSDT @@ -105,6 +106,22 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle, return status; } +static bool acpi_check_device_is_ignored(acpi_handle handle) +{ + acpi_status status; + u64 addr; + + /* Check if it should ignore the UART device */ + if (spcr_uart_addr != 0) { + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, + &addr); + if (ACPI_SUCCESS(status) && addr == spcr_uart_addr) + return true; + } + + return false; +} + int acpi_bus_get_status(struct acpi_device *device) { acpi_status status; @@ -114,7 +131,8 @@ int acpi_bus_get_status(struct acpi_device *device) if (ACPI_FAILURE(status)) return -ENODEV; - acpi_set_device_status(device, sta); + if (!acpi_check_device_is_ignored(device->handle)) + acpi_set_device_status(device, sta); if (device->status.functional && !device->status.present) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: " @@ -1070,6 +1088,8 @@ EXPORT_SYMBOL_GPL(acpi_kobj); static int __init acpi_init(void) { int result; + acpi_status status; + struct acpi_table_stao *stao_ptr; if (acpi_disabled) { printk(KERN_INFO PREFIX "Interpreter disabled.\n"); @@ -1082,6 +1102,22 @@ static int __init acpi_init(void) acpi_kobj = NULL; } + /* 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) && stao_ptr->ignore_uart) { + 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 "STAO table present, but SPCR is missing.\n"); + } + init_acpi_device_notify(); result = acpi_bus_init(); if (result) {