From patchwork Tue Nov 23 14:07:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Winiarska, Iwona" X-Patchwork-Id: 12693469 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 61FAFC433F5 for ; Tue, 23 Nov 2021 14:14:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=+SxMK9wX5zCiZxyAPK84IwjxJ9rYCMpL7kFGhFcxKHo=; b=pDob88ZF8YLOVM qf8VgMGXAnH61TKwos6CvkwRjEEK2FlnOG83AiqjoPwLWsoB9ckqCa8KKxdY1JXLyboDqAEemps6B 5+M4EMQOGVwaQM1x3YemWrmdZGRxEpzeYFKJaAqhJj/JSgaJd7GQrTthVe5TQJTHNdBQKv7pbKIUt PEIQM/GoVkJ7P+/s3u1XIxL5FMYT8os/e/3plKNP1pfkc5dYKdExfGZUtX0nMvtbRKn7GxmCp+Hgz 96WdycBY14DlZXZa8+WAXY/SSmEW4OCuyTvf5BNRflheKV1ACo6QgRL6KaSjtOskeTYNnjxlmfFvy y3ReL0CUdYjD2L8YEQmw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mpWXd-002VeE-Tm; Tue, 23 Nov 2021 14:13:02 +0000 Received: from mga12.intel.com ([192.55.52.136]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mpWVL-002UMO-AC for linux-arm-kernel@lists.infradead.org; Tue, 23 Nov 2021 14:10:41 +0000 X-IronPort-AV: E=McAfee;i="6200,9189,10176"; a="215055693" X-IronPort-AV: E=Sophos;i="5.87,257,1631602800"; d="scan'208";a="215055693" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2021 06:10:38 -0800 X-IronPort-AV: E=Sophos;i="5.87,257,1631602800"; d="scan'208";a="597095243" Received: from romanagn-mobl.ger.corp.intel.com (HELO localhost) ([10.249.144.24]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2021 06:10:30 -0800 From: Iwona Winiarska To: linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, Greg Kroah-Hartman Cc: 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 , Borislav Petkov , Pierre-Louis Bossart , Tony Luck , Andy Shevchenko , Dan Williams , Randy Dunlap , Zev Weiss , David Muller , Dave Hansen , Iwona Winiarska Subject: [PATCH v4 07/13] peci: Add sysfs interface for PECI bus Date: Tue, 23 Nov 2021 15:07:00 +0100 Message-Id: <20211123140706.2945700-8-iwona.winiarska@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211123140706.2945700-1-iwona.winiarska@intel.com> References: <20211123140706.2945700-1-iwona.winiarska@intel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211123_061039_460269_BC24B6E1 X-CRM114-Status: GOOD ( 25.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 c3361e6e043a..e993615cf521 100644 --- a/drivers/peci/core.c +++ b/drivers/peci/core.c @@ -29,7 +29,7 @@ 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; @@ -162,6 +162,7 @@ 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 2b3a2d893aaf..d10ed1cfcd48 100644 --- a/drivers/peci/device.c +++ b/drivers/peci/device.c @@ -116,5 +116,6 @@ 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 +};