From patchwork Tue Aug 3 11:31:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Winiarska, Iwona" X-Patchwork-Id: 12415993 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 C972CC432BE for ; Tue, 3 Aug 2021 11:35:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B21FD60F11 for ; Tue, 3 Aug 2021 11:35:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235676AbhHCLfr (ORCPT ); Tue, 3 Aug 2021 07:35:47 -0400 Received: from mga09.intel.com ([134.134.136.24]:51999 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235734AbhHCLfq (ORCPT ); Tue, 3 Aug 2021 07:35:46 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10064"; a="213643838" X-IronPort-AV: E=Sophos;i="5.84,291,1620716400"; d="scan'208";a="213643838" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Aug 2021 04:35:34 -0700 X-IronPort-AV: E=Sophos;i="5.84,291,1620716400"; d="scan'208";a="670394085" Received: from jdanieck-mobl1.ger.corp.intel.com (HELO localhost) ([10.249.128.99]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Aug 2021 04:35:28 -0700 From: Iwona Winiarska To: linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, Greg Kroah-Hartman Cc: x86@kernel.org, devicetree@vger.kernel.org, linux-aspeed@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, Rob Herring , Joel Stanley , Andrew Jeffery , Jean Delvare , Guenter Roeck , Arnd Bergmann , Olof Johansson , Jonathan Corbet , Thomas Gleixner , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Yazen Ghannam , Mauro Carvalho Chehab , Pierre-Louis Bossart , Tony Luck , Andy Shevchenko , Jae Hyun Yoo , Dan Williams , Randy Dunlap , Zev Weiss , David Muller , Iwona Winiarska Subject: [PATCH v2 09/15] peci: Add sysfs interface for PECI bus Date: Tue, 3 Aug 2021 13:31:28 +0200 Message-Id: <20210803113134.2262882-10-iwona.winiarska@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210803113134.2262882-1-iwona.winiarska@intel.com> References: <20210803113134.2262882-1-iwona.winiarska@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org PECI devices may not be discoverable at the time when PECI controller is being added (e.g. BMC can boot up when the Host system is still in S5). Since we currently don't have the capabilities to figure out the Host system state inside the PECI subsystem itself, we have to rely on userspace to do it for us. In the future, PECI subsystem may be expanded with mechanisms that allow us to avoid depending on userspace interaction (e.g. CPU presence could be detected using GPIO, and the information on whether it's discoverable could be obtained over IPMI). Unfortunately, those methods may ultimately not be available (support will vary from platform to platform), which means that we still need platform independent method triggered by userspace. Signed-off-by: Iwona Winiarska --- Documentation/ABI/testing/sysfs-bus-peci | 16 +++++ drivers/peci/Makefile | 2 +- drivers/peci/core.c | 3 +- drivers/peci/device.c | 1 + drivers/peci/internal.h | 5 ++ drivers/peci/sysfs.c | 82 ++++++++++++++++++++++++ 6 files changed, 107 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-peci create mode 100644 drivers/peci/sysfs.c diff --git a/Documentation/ABI/testing/sysfs-bus-peci b/Documentation/ABI/testing/sysfs-bus-peci new file mode 100644 index 000000000000..56c2b2216bbd --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-peci @@ -0,0 +1,16 @@ +What: /sys/bus/peci/rescan +Date: July 2021 +KernelVersion: 5.15 +Contact: Iwona Winiarska +Description: + Writing a non-zero value to this attribute will + initiate scan for PECI devices on all PECI controllers + in the system. + +What: /sys/bus/peci/devices/-/remove +Date: July 2021 +KernelVersion: 5.15 +Contact: Iwona Winiarska +Description: + Writing a non-zero value to this attribute will + remove the PECI device and any of its children. diff --git a/drivers/peci/Makefile b/drivers/peci/Makefile index c5f9d3fe21bb..917f689e147a 100644 --- a/drivers/peci/Makefile +++ b/drivers/peci/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only # Core functionality -peci-y := core.o request.o device.o +peci-y := core.o request.o device.o sysfs.o obj-$(CONFIG_PECI) += peci.o # Hardware specific bus drivers diff --git a/drivers/peci/core.c b/drivers/peci/core.c index d143f1a7fe98..c473acb3c2a0 100644 --- a/drivers/peci/core.c +++ b/drivers/peci/core.c @@ -34,7 +34,7 @@ struct device_type peci_controller_type = { .release = peci_controller_dev_release, }; -static int peci_controller_scan_devices(struct peci_controller *controller) +int peci_controller_scan_devices(struct peci_controller *controller) { int ret; u8 addr; @@ -159,6 +159,7 @@ EXPORT_SYMBOL_NS_GPL(devm_peci_controller_add, PECI); struct bus_type peci_bus_type = { .name = "peci", + .bus_groups = peci_bus_groups, }; static int __init peci_init(void) diff --git a/drivers/peci/device.c b/drivers/peci/device.c index 32811248997b..d77d9dabd51e 100644 --- a/drivers/peci/device.c +++ b/drivers/peci/device.c @@ -110,5 +110,6 @@ static void peci_device_release(struct device *dev) } struct device_type peci_device_type = { + .groups = peci_device_groups, .release = peci_device_release, }; diff --git a/drivers/peci/internal.h b/drivers/peci/internal.h index 57d11a902c5d..978e12c8e1d3 100644 --- a/drivers/peci/internal.h +++ b/drivers/peci/internal.h @@ -8,6 +8,7 @@ #include struct peci_controller; +struct attribute_group; struct peci_device; struct peci_request; @@ -19,12 +20,16 @@ struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u void peci_request_free(struct peci_request *req); extern struct device_type peci_device_type; +extern const struct attribute_group *peci_device_groups[]; int peci_device_create(struct peci_controller *controller, u8 addr); void peci_device_destroy(struct peci_device *device); extern struct bus_type peci_bus_type; +extern const struct attribute_group *peci_bus_groups[]; extern struct device_type peci_controller_type; +int peci_controller_scan_devices(struct peci_controller *controller); + #endif /* __PECI_INTERNAL_H */ diff --git a/drivers/peci/sysfs.c b/drivers/peci/sysfs.c new file mode 100644 index 000000000000..db9ef05776e3 --- /dev/null +++ b/drivers/peci/sysfs.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) 2021 Intel Corporation + +#include +#include +#include + +#include "internal.h" + +static int rescan_controller(struct device *dev, void *data) +{ + if (dev->type != &peci_controller_type) + return 0; + + return peci_controller_scan_devices(to_peci_controller(dev)); +} + +static ssize_t rescan_store(struct bus_type *bus, const char *buf, size_t count) +{ + bool res; + int ret; + + ret = kstrtobool(buf, &res); + if (ret) + return ret; + + if (!res) + return count; + + ret = bus_for_each_dev(&peci_bus_type, NULL, NULL, rescan_controller); + if (ret) + return ret; + + return count; +} +static BUS_ATTR_WO(rescan); + +static struct attribute *peci_bus_attrs[] = { + &bus_attr_rescan.attr, + NULL +}; + +static const struct attribute_group peci_bus_group = { + .attrs = peci_bus_attrs, +}; + +const struct attribute_group *peci_bus_groups[] = { + &peci_bus_group, + NULL +}; + +static ssize_t remove_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct peci_device *device = to_peci_device(dev); + bool res; + int ret; + + ret = kstrtobool(buf, &res); + if (ret) + return ret; + + if (res && device_remove_file_self(dev, attr)) + peci_device_destroy(device); + + return count; +} +static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0200, NULL, remove_store); + +static struct attribute *peci_device_attrs[] = { + &dev_attr_remove.attr, + NULL +}; + +static const struct attribute_group peci_device_group = { + .attrs = peci_device_attrs, +}; + +const struct attribute_group *peci_device_groups[] = { + &peci_device_group, + NULL +};