From patchwork Thu Mar 31 09:37:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Octavian Purdila X-Patchwork-Id: 8710351 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id F1D939F30C for ; Thu, 31 Mar 2016 09:39:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E94B02025B for ; Thu, 31 Mar 2016 09:39:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3B7B20295 for ; Thu, 31 Mar 2016 09:39:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755747AbcCaJiR (ORCPT ); Thu, 31 Mar 2016 05:38:17 -0400 Received: from mga09.intel.com ([134.134.136.24]:8177 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755409AbcCaJiO (ORCPT ); Thu, 31 Mar 2016 05:38:14 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 31 Mar 2016 02:38:14 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,421,1455004800"; d="scan'208";a="945123711" Received: from opurdila-mobl.rb.intel.com ([10.237.104.166]) by orsmga002.jf.intel.com with ESMTP; 31 Mar 2016 02:38:11 -0700 From: Octavian Purdila To: "Rafael J. Wysocki" , Len Brown , Matt Fleming , Mark Brown , Wolfram Sang Cc: Joel Becker , Christoph Hellwig , linux-acpi@vger.kernel.org, linux-efi@vger.kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, irina.tirdea@intel.com, Octavian Purdila Subject: [RFC PATCH 10/10] acpi: add support for loading SSDTs via configfs Date: Thu, 31 Mar 2016 12:37:06 +0300 Message-Id: <1459417026-6697-11-git-send-email-octavian.purdila@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1459417026-6697-1-git-send-email-octavian.purdila@intel.com> References: <1459417026-6697-1-git-send-email-octavian.purdila@intel.com> Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@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 Add support for acpi_user_table configfs items that allows the user to load new tables. The data attributes contains the table data and once it is filled from userspace the table is loaded and ACPI devices are enumerated. Signed-off-by: Octavian Purdila --- Documentation/ABI/testing/configfs-acpi | 16 +++++ Documentation/acpi/ssdt-overlays.txt | 14 +++++ drivers/acpi/configfs.c | 104 ++++++++++++++++++++++++++++++++ 3 files changed, 134 insertions(+) diff --git a/Documentation/ABI/testing/configfs-acpi b/Documentation/ABI/testing/configfs-acpi index 0c806aa..34a205e 100644 --- a/Documentation/ABI/testing/configfs-acpi +++ b/Documentation/ABI/testing/configfs-acpi @@ -5,3 +5,19 @@ Contact: linux-acpi@vger.kernel.org Description: This represents the ACPI subsystem entry point directory. It contains sub-groups corresponding to ACPI configurable options. + +What: /config/acpi/table +Date: April 2016 +KernelVersion: 4.6 +Description: + + This group contains the configuration for user defined ACPI + tables. The attributes of a user define table are: + + data - a binary write only attribute that the user can use to + fill in the ACPI aml definitions. Once the aml data is + written to this file and the file is closed the table + will be loaded and ACPI device will be enumerated. To + check if the operation is successful the user must check + the error code for close(). If the operation is + successful, subsequent writes to this attribute will fail. diff --git a/Documentation/acpi/ssdt-overlays.txt b/Documentation/acpi/ssdt-overlays.txt index 7c588be..a88a2ce 100644 --- a/Documentation/acpi/ssdt-overlays.txt +++ b/Documentation/acpi/ssdt-overlays.txt @@ -158,3 +158,17 @@ tmp=$(mktemp) /bin/echo -ne "\007\000\000\000" | cat - $filename > $tmp dd if=$tmp of="$EFIVARFS/$name-$guid" bs=$(stat -c %s $tmp) rm $tmp + +== Loading ACPI SSDTs from configfs == + +This option allows loading of user defined SSDTs from userspace via the configfs +interface. The CONFIG_ACPI_CONFIGFS option must be select and configfs must be +mounted. In the following examples, we assume that configfs has been mounted in +/config. + +New tables can be loading by creating new directories in /config/acpi/table/ and +writing the SSDT aml code in the data attribute: + +cd /config/acpi/table +mkdir my_ssdt +cat ~/ssdt.aml > my_ssdt/data diff --git a/drivers/acpi/configfs.c b/drivers/acpi/configfs.c index 96aa3d8..3a194806 100644 --- a/drivers/acpi/configfs.c +++ b/drivers/acpi/configfs.c @@ -13,6 +13,104 @@ #include #include +static struct config_group *acpi_table_group; + +struct acpi_user_table { + struct config_item cfg; + struct acpi_table_header *table; +}; + +static ssize_t acpi_table_data_write(struct config_item *cfg, + const void *data, size_t size) +{ + struct acpi_table_header *header = (struct acpi_table_header *)data; + struct acpi_user_table *table; + int ret; + + table = container_of(cfg, struct acpi_user_table, cfg); + + if (table->table) { + pr_err("ACPI configfs table: table already loaded\n"); + return -EBUSY; + } + + if (header->length != size) { + pr_err("ACPI configfs table: invalid table length\n"); + return -EINVAL; + } + + if (memcmp(header->signature, ACPI_SIG_SSDT, 4)) { + pr_err("ACPI configfs table: invalid table signature\n"); + return -EINVAL; + } + + table = container_of(cfg, struct acpi_user_table, cfg); + + table->table = kmemdup(header, header->length, GFP_KERNEL); + if (!table->table) + return -ENOMEM; + + ret = acpi_load_table(table->table); + if (ret) { + kfree(table->table); + table->table = NULL; + } + + add_taint(TAINT_OVERLAY_ACPI_TABLE, LOCKDEP_STILL_OK); + + return ret; +} + +#define MAX_ACPI_TABLE_SIZE (128 * 1024) + +CONFIGFS_BIN_ATTR_WO(acpi_table_, data, NULL, MAX_ACPI_TABLE_SIZE); + +struct configfs_bin_attribute *acpi_table_bin_attrs[] = { + &acpi_table_attr_data, + NULL, +}; + +static struct config_item_type acpi_table_type = { + .ct_owner = THIS_MODULE, + .ct_bin_attrs = acpi_table_bin_attrs, +}; + +static struct config_item *acpi_table_make_item(struct config_group *group, + const char *name) +{ + struct acpi_user_table *table; + + table = kzalloc(sizeof(*table), GFP_KERNEL); + if (!table) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&table->cfg, name, &acpi_table_type); + return &table->cfg; +} + +struct configfs_group_operations acpi_table_group_ops = { + .make_item = acpi_table_make_item, +}; + +static struct config_item_type acpi_tables_type = { + .ct_owner = THIS_MODULE, + .ct_group_ops = &acpi_table_group_ops, +}; + +static struct config_item_type acpi_root_group_type = { + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem acpi_configfs = { + .su_group = { + .cg_item = { + .ci_namebuf = "acpi", + .ci_type = &acpi_root_group_type, + }, + }, + .su_mutex = __MUTEX_INITIALIZER(acpi_configfs.su_mutex), +}; + static int __init acpi_configfs_init(void) { int ret; @@ -24,12 +122,18 @@ static int __init acpi_configfs_init(void) if (ret) return ret; + acpi_table_group = configfs_register_default_group(root, "table", + &acpi_tables_type); + if (IS_ERR(acpi_table_group)) + return PTR_ERR(acpi_table_group); + return 0; } module_init(acpi_configfs_init); static void __exit acpi_configfs_exit(void) { + configfs_unregister_default_group(acpi_table_group); configfs_unregister_subsystem(&acpi_configfs); } module_exit(acpi_configfs_exit);