From patchwork Mon May 4 18:16:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: srinivas pandruvada X-Patchwork-Id: 11527351 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 16C0815AB for ; Mon, 4 May 2020 18:17:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03C5B20661 for ; Mon, 4 May 2020 18:17:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731949AbgEDSQn (ORCPT ); Mon, 4 May 2020 14:16:43 -0400 Received: from mga12.intel.com ([192.55.52.136]:27142 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730657AbgEDSQl (ORCPT ); Mon, 4 May 2020 14:16:41 -0400 IronPort-SDR: VLJwayYw3x53mUP8Kp+OcOIC3+n0SK2gHXim9pd4+nYLP5WtZdQsBQ8+Hi71ZiEB9DZqQV+3cb pjUemP/yny1Q== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 May 2020 11:16:32 -0700 IronPort-SDR: oWB94z3vmcJwRlcip6yGYRP9hzAigw19BqdDV8aTAAD7ubvVwZLi41gRSjbl268guVtRt/XHPN RrEpp1yYzoew== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,352,1583222400"; d="scan'208";a="259427109" Received: from spandruv-mobl.amr.corp.intel.com ([10.212.145.237]) by orsmga003.jf.intel.com with ESMTP; 04 May 2020 11:16:31 -0700 From: Srinivas Pandruvada To: rui.zhang@intel.com, daniel.lezcano@linaro.org, amit.kucheria@verdurent.com Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Srinivas Pandruvada Subject: [RFC][PATCH 1/5] thermal: Add support for /dev/thermal_notify Date: Mon, 4 May 2020 11:16:12 -0700 Message-Id: <20200504181616.175477-2-srinivas.pandruvada@linux.intel.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200504181616.175477-1-srinivas.pandruvada@linux.intel.com> References: <20200504181616.175477-1-srinivas.pandruvada@linux.intel.com> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org This change adds an optional feature to add a new device entry /dev/thermal_notify. When config CONFIG_THERMAL_USER_EVENT_INTERFACE is selected, this new device entry is created. Thermal core or any thermal driver can use thermal_dev_send_event() interface to send events. Each user events follows a standard format: - zone_id - event_id - event_data - reserved for future, currently 0s User space can basically: fd = open ("/dev/thermal_notify") In a loop read (fd) read and process event or fd = open ("/dev/thermal_notify") Set the fs as non blocking In a loop Use poll() and wait read and process event There are predefined events added to thermal.h. Based on need they can be extended. Signed-off-by: Srinivas Pandruvada --- drivers/thermal/Kconfig | 9 ++ drivers/thermal/Makefile | 3 + drivers/thermal/thermal_dev_if.c | 195 +++++++++++++++++++++++++++++++ include/linux/thermal.h | 24 ++++ 4 files changed, 231 insertions(+) create mode 100644 drivers/thermal/thermal_dev_if.c diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index 91af271e9bb0..27d05d62458e 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -78,6 +78,15 @@ config THERMAL_WRITABLE_TRIPS Say 'Y' here if you would like to allow userspace tools to change trip temperatures. +config THERMAL_USER_EVENT_INTERFACE + bool "Allow user space to read thermal events from a dev file" + help + This option allows a user space program to read thermal events + via /dev/thermal_notify file. + + Say 'Y' here if you would like to allow userspace programs to + read thermal events. + choice prompt "Default Thermal governor" default THERMAL_DEFAULT_GOV_STEP_WISE diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index 8c8ed7b79915..8f65832d755a 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -11,6 +11,9 @@ thermal_sys-y += thermal_core.o thermal_sysfs.o \ thermal_sys-$(CONFIG_THERMAL_HWMON) += thermal_hwmon.o thermal_sys-$(CONFIG_THERMAL_OF) += of-thermal.o +# Thermal user space events +obj-$(CONFIG_THERMAL_USER_EVENT_INTERFACE) += thermal_dev_if.o + # governors thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += fair_share.o thermal_sys-$(CONFIG_THERMAL_GOV_BANG_BANG) += gov_bang_bang.o diff --git a/drivers/thermal/thermal_dev_if.c b/drivers/thermal/thermal_dev_if.c new file mode 100644 index 000000000000..763bfe9eef9d --- /dev/null +++ b/drivers/thermal/thermal_dev_if.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Thermal device file interface + * Copyright (c) 2020, Intel Corporation. + * All rights reserved. + * + * Author: Srinivas Pandruvada + */ + +#include +#include +#include +#include +#include +#include +#include + +#define THERMAL_DEV_FIFO_SIZE 1024 + +struct thermal_chdev_sample { + int zone_id; + int event; + u64 event_data; + u64 reserved; +}; + +struct thermal_chdev { + struct miscdevice therm_dev; + struct kfifo data_fifo; + unsigned long misc_opened; + wait_queue_head_t wait; +}; + +static DEFINE_MUTEX(thermal_chdev_mutex); +static struct thermal_chdev *thermal_chdev; + +static int thermal_chdev_open(struct inode *inode, struct file *file) +{ + struct thermal_chdev *chdev; + + chdev = container_of(file->private_data, struct thermal_chdev, therm_dev); + + /* We essentially have single reader and writer */ + if (test_and_set_bit(0, &chdev->misc_opened)) + return -EBUSY; + + return stream_open(inode, file); +} + +static int thermal_chdev_release(struct inode *inode, struct file *file) +{ + struct thermal_chdev *chdev; + + chdev = container_of(file->private_data, struct thermal_chdev, therm_dev); + + clear_bit(0, &chdev->misc_opened); + + return 0; +} + +static __poll_t thermal_chdev_poll(struct file *file, struct poll_table_struct *wait) +{ + struct thermal_chdev *chdev; + __poll_t mask = 0; + + chdev = container_of(file->private_data, struct thermal_chdev, therm_dev); + + poll_wait(file, &chdev->wait, wait); + + if (!kfifo_is_empty(&chdev->data_fifo)) + mask = EPOLLIN | EPOLLRDNORM; + + return mask; +} + +static ssize_t thermal_chdev_read(struct file *file, char __user *buf, size_t count, loff_t *f_ps) +{ + struct thermal_chdev *chdev; + unsigned int copied; + int ret; + + chdev = container_of(file->private_data, struct thermal_chdev, therm_dev); + + if (count < sizeof(struct thermal_chdev_sample)) + return -EINVAL; + + do { + if (kfifo_is_empty(&chdev->data_fifo)) { + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = wait_event_interruptible(chdev->wait, !kfifo_is_empty(&chdev->data_fifo)); + if (ret) + return ret; + } + ret = kfifo_to_user(&chdev->data_fifo, buf, count, &copied); + if (ret) + return ret; + + } while (copied == 0); + + return copied; +} + +static int thermal_chdev_capture_sample(struct thermal_chdev *chdev, struct thermal_chdev_sample *sample) +{ + int ret = 0; + + if (!test_bit(0, &chdev->misc_opened)) + return 0; + + mutex_lock(&thermal_chdev_mutex); + if (kfifo_avail(&chdev->data_fifo) >= sizeof(*sample)) { + kfifo_in(&chdev->data_fifo, (unsigned char *)sample, sizeof(*sample)); + wake_up(&chdev->wait); + } else { + ret = -ENOMEM; + } + mutex_unlock(&thermal_chdev_mutex); + + return ret; +} + +static const struct file_operations thermal_chdev_fops = { + .open = thermal_chdev_open, + .read = thermal_chdev_read, + .release = thermal_chdev_release, + .poll = thermal_chdev_poll, + .llseek = noop_llseek, +}; + +static int thermal_dev_if_add(void) +{ + int ret; + + if (thermal_chdev) + return 0; + + thermal_chdev = kzalloc(sizeof(*thermal_chdev), GFP_KERNEL); + if (!thermal_chdev) + return -ENOMEM; + + ret = kfifo_alloc(&thermal_chdev->data_fifo, THERMAL_DEV_FIFO_SIZE, GFP_KERNEL); + if (ret) + goto free_mem; + + init_waitqueue_head(&thermal_chdev->wait); + + thermal_chdev->therm_dev.minor = MISC_DYNAMIC_MINOR; + thermal_chdev->therm_dev.name = "thermal_notify"; + thermal_chdev->therm_dev.fops = &thermal_chdev_fops; + ret = misc_register(&thermal_chdev->therm_dev); + if (ret) { + kfifo_free(&thermal_chdev->data_fifo); + goto free_mem; + } + + return 0; + +free_mem: + kfree(thermal_chdev); + thermal_chdev = NULL; + return ret; +} + +/** + * thermal_dev_send_event() - Send thermal event to user space + * @zone_id: Zone id of the caller + * @event: A predefined thermal event + * @event_data: Event specific data + * + * An interface to send event to user space with an optional associated + * data. + * + * Return: 0 on success, other values on error. + */ +int thermal_dev_send_event(int zone_id, enum thermal_device_events event, u64 event_data) +{ + struct thermal_chdev_sample sample; + + if (!thermal_chdev) { + int ret; + + ret = thermal_dev_if_add(); + if (ret) + return ret; + } + + sample.zone_id = zone_id; + sample.event = event; + sample.event_data = event_data; + sample.reserved = 0; + return thermal_chdev_capture_sample(thermal_chdev, &sample); +} +EXPORT_SYMBOL_GPL(thermal_dev_send_event); diff --git a/include/linux/thermal.h b/include/linux/thermal.h index c91b1e344d56..f5e1e7c6a9a2 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -543,4 +543,28 @@ static inline void thermal_notify_framework(struct thermal_zone_device *tz, { } #endif /* CONFIG_THERMAL */ +enum thermal_device_events { + THERMAL_TEMP_SAMPLE = 0, + THERMAL_ZONE_CREATE, + THERMAL_ZONE_DELETE, + THERMAL_ZONE_DISABLED, + THERMAL_ZONE_ENABLED, + THERMAL_TEMP_LOW_THRES, + THERMAL_TEMP_HIGH_THRES, + THERMAL_TRIP_ADD, + THERMAL_TRIP_DELETE, + THERMAL_TRIP_UPDATE, + THERMAL_TRIP_REACHED, + THERMAL_PERF_CHANGED, +}; + +#ifdef CONFIG_THERMAL_USER_EVENT_INTERFACE +int thermal_dev_send_event(int zone_id, enum thermal_device_events event, u64 event_data); +#else +int thermal_dev_send_event(int zone_id, enum thermal_device_events event, u64 event_data) +{ + return 0; +} +#endif + #endif /* __THERMAL_H__ */