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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252// SPDX-License-Identifier: GPL-2.0/* * Copyright 2024, Intel Corporation * * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> * * Thermal subsystem testing facility. * * This facility allows the thermal core functionality to be exercised in a * controlled way in order to verify its behavior. * * It resides in the "thermal-testing" directory under the debugfs root and * starts with a single file called "command" which can be written a string * representing a thermal testing facility command. * * The currently supported commands are listed in the tt_commands enum below. * * The "addtz" command causes a new test thermal zone template to be created, * for example: * * # echo addtz > /sys/kernel/debug/thermal-testing/command * * That template will be represented as a subdirectory in the "thermal-testing" * directory, for example * * # ls /sys/kernel/debug/thermal-testing/ * command tz0 * * The thermal zone template can be populated with trip points with the help of * the "tzaddtrip" command, for example: * * # echo tzaddtrip:0 > /sys/kernel/debug/thermal-testing/command * * which causes a trip point template to be added to the test thermal zone * template 0 (represented by the tz0 subdirectory in "thermal-testing"). * * # ls /sys/kernel/debug/thermal-testing/tz0 * init_temp temp trip_0_temp trip_0_hyst * * The temperature of a trip point template is initially THERMAL_TEMP_INVALID * and its hysteresis is initially 0. They can be adjusted by writing to the * "trip_x_temp" and "trip_x_hyst" files correspoinding to that trip point * template, respectively. * * The initial temperature of a thermal zone based on a template can be set by * writing to the "init_temp" file in its directory under "thermal-testing", for * example: * * echo 50000 > /sys/kernel/debug/thermal-testing/tz0/init_temp * * When ready, "tzreg" command can be used for registering and enabling a * thermal zone based on a given template with the thermal core, for example * * # echo tzreg:0 > /sys/kernel/debug/thermal-testing/command * * In this case, test thermal zone template 0 is used for registering a new * thermal zone and the set of trip point templates associated with it is used * for populating the new thermal zone's trip points table. The type of the new * thermal zone is "test_tz". * * The temperature and hysteresis of all of the trip points in that new thermal * zone are adjustable via sysfs, so they can be updated at any time. * * The current temperature of the new thermal zone can be set by writing to the * "temp" file in the corresponding thermal zone template's directory under * "thermal-testing", for example * * echo 10000 > /sys/kernel/debug/thermal-testing/tz0/temp * * which will also trigger a temperature update for this zone in the thermal * core, including checking its trip points, sending notifications to user space * if any of them have been crossed and so on. * * When it is not needed any more, a test thermal zone template can be deleted * with the help of the "deltz" command, for example * * # echo deltz:0 > /sys/kernel/debug/thermal-testing/command * * which will also unregister the thermal zone based on it, if present. */
#define pr_fmt(fmt) "thermal-testing: " fmt
#include <linux/debugfs.h>#include <linux/module.h>
#include "thermal_testing.h"
struct workqueue_struct *tt_wq __ro_after_init;
struct dentry *d_testing __ro_after_init;static struct dentry *d_command __ro_after_init;
#define TT_COMMAND_SIZE 16
enum tt_commands { TT_CMD_ADDTZ, TT_CMD_DELTZ, TT_CMD_TZADDTRIP, TT_CMD_TZREG, TT_CMD_TZUNREG,};
static const char *tt_command_strings[] = { [TT_CMD_ADDTZ] = "addtz", [TT_CMD_DELTZ] = "deltz", [TT_CMD_TZADDTRIP] = "tzaddtrip", [TT_CMD_TZREG] = "tzreg", [TT_CMD_TZUNREG] = "tzunreg",};
static int tt_command_exec(int index, const char *arg){ int ret;
switch (index) { case TT_CMD_ADDTZ: ret = tt_add_tz(); break;
case TT_CMD_DELTZ: if (!arg || !*arg) return -EINVAL;
ret = tt_del_tz(arg); break;
case TT_CMD_TZADDTRIP: if (!arg || !*arg) return -EINVAL;
ret = tt_zone_add_trip(arg); break;
case TT_CMD_TZREG: if (!arg || !*arg) return -EINVAL;
ret = tt_zone_reg(arg); break;
case TT_CMD_TZUNREG: if (!arg || !*arg) return -EINVAL;
ret = tt_zone_unreg(arg); break;
default: ret = -EINVAL; break; }
return ret;}
static ssize_t tt_command_process(char *s){ char *arg; int i;
strim(s);
arg = strchr(s, ':'); if (arg) { *arg = '\0'; arg++; }
for (i = 0; i < ARRAY_SIZE(tt_command_strings); i++) { if (!strcmp(s, tt_command_strings[i])) return tt_command_exec(i, arg); }
return -EINVAL;}
static ssize_t tt_command_write(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos){ char buf[TT_COMMAND_SIZE]; ssize_t ret;
if (*ppos) return -EINVAL;
if (count > TT_COMMAND_SIZE - 1) return -E2BIG;
if (copy_from_user(buf, user_buf, count)) return -EFAULT; buf[count] = '\0';
ret = tt_command_process(buf); if (ret) return ret;
return count;}
static const struct file_operations tt_command_fops = { .write = tt_command_write, .open = simple_open, .llseek = default_llseek,};
static int __init thermal_testing_init(void){ int error;
tt_wq = alloc_workqueue("thermal_testing", WQ_UNBOUND, 0); if (!tt_wq) return -ENOMEM;
d_testing = debugfs_create_dir("thermal-testing", NULL); if (IS_ERR(d_testing)) { error = PTR_ERR(d_testing); goto destroy_wq; }
d_command = debugfs_create_file("command", 0200, d_testing, NULL, &tt_command_fops); if (IS_ERR(d_command)) { error = PTR_ERR(d_command); goto remove_d_testing; }
return 0;
remove_d_testing: debugfs_remove(d_testing);destroy_wq: destroy_workqueue(tt_wq); return error;}module_init(thermal_testing_init);
static void __exit thermal_testing_exit(void){ /* First, prevent new commands from being entered. */ debugfs_remove(d_command); /* Flush commands in progress (if any). */ flush_workqueue(tt_wq); destroy_workqueue(tt_wq); /* Remove the directory structure and clean up. */ debugfs_remove(d_testing); tt_zone_cleanup();}module_exit(thermal_testing_exit);
MODULE_DESCRIPTION("Thermal core testing facility");MODULE_LICENSE("GPL v2");