From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/thermal/cpuidle_cooling.c | 270 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 270 insertions(+) create mode 100644 drivers/thermal/cpuidle_cooling.c (limited to 'drivers/thermal/cpuidle_cooling.c') diff --git a/drivers/thermal/cpuidle_cooling.c b/drivers/thermal/cpuidle_cooling.c new file mode 100644 index 0000000000..69f4c0a8df --- /dev/null +++ b/drivers/thermal/cpuidle_cooling.c @@ -0,0 +1,270 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Linaro Limited. + * + * Author: Daniel Lezcano + * + */ +#define pr_fmt(fmt) "cpuidle cooling: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/** + * struct cpuidle_cooling_device - data for the idle cooling device + * @ii_dev: an atomic to keep track of the last task exiting the idle cycle + * @state: a normalized integer giving the state of the cooling device + */ +struct cpuidle_cooling_device { + struct idle_inject_device *ii_dev; + unsigned long state; +}; + +/** + * cpuidle_cooling_runtime - Running time computation + * @idle_duration_us: CPU idle time to inject in microseconds + * @state: a percentile based number + * + * The running duration is computed from the idle injection duration + * which is fixed. If we reach 100% of idle injection ratio, that + * means the running duration is zero. If we have a 50% ratio + * injection, that means we have equal duration for idle and for + * running duration. + * + * The formula is deduced as follows: + * + * running = idle x ((100 / ratio) - 1) + * + * For precision purpose for integer math, we use the following: + * + * running = (idle x 100) / ratio - idle + * + * For example, if we have an injected duration of 50%, then we end up + * with 10ms of idle injection and 10ms of running duration. + * + * Return: An unsigned int for a usec based runtime duration. + */ +static unsigned int cpuidle_cooling_runtime(unsigned int idle_duration_us, + unsigned long state) +{ + if (!state) + return 0; + + return ((idle_duration_us * 100) / state) - idle_duration_us; +} + +/** + * cpuidle_cooling_get_max_state - Get the maximum state + * @cdev : the thermal cooling device + * @state : a pointer to the state variable to be filled + * + * The function always returns 100 as the injection ratio. It is + * percentile based for consistency accross different platforms. + * + * Return: The function can not fail, it is always zero + */ +static int cpuidle_cooling_get_max_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + /* + * Depending on the configuration or the hardware, the running + * cycle and the idle cycle could be different. We want to + * unify that to an 0..100 interval, so the set state + * interface will be the same whatever the platform is. + * + * The state 100% will make the cluster 100% ... idle. A 0% + * injection ratio means no idle injection at all and 50% + * means for 10ms of idle injection, we have 10ms of running + * time. + */ + *state = 100; + + return 0; +} + +/** + * cpuidle_cooling_get_cur_state - Get the current cooling state + * @cdev: the thermal cooling device + * @state: a pointer to the state + * + * The function just copies the state value from the private thermal + * cooling device structure, the mapping is 1 <-> 1. + * + * Return: The function can not fail, it is always zero + */ +static int cpuidle_cooling_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + struct cpuidle_cooling_device *idle_cdev = cdev->devdata; + + *state = idle_cdev->state; + + return 0; +} + +/** + * cpuidle_cooling_set_cur_state - Set the current cooling state + * @cdev: the thermal cooling device + * @state: the target state + * + * The function checks first if we are initiating the mitigation which + * in turn wakes up all the idle injection tasks belonging to the idle + * cooling device. In any case, it updates the internal state for the + * cooling device. + * + * Return: The function can not fail, it is always zero + */ +static int cpuidle_cooling_set_cur_state(struct thermal_cooling_device *cdev, + unsigned long state) +{ + struct cpuidle_cooling_device *idle_cdev = cdev->devdata; + struct idle_inject_device *ii_dev = idle_cdev->ii_dev; + unsigned long current_state = idle_cdev->state; + unsigned int runtime_us, idle_duration_us; + + idle_cdev->state = state; + + idle_inject_get_duration(ii_dev, &runtime_us, &idle_duration_us); + + runtime_us = cpuidle_cooling_runtime(idle_duration_us, state); + + idle_inject_set_duration(ii_dev, runtime_us, idle_duration_us); + + if (current_state == 0 && state > 0) { + idle_inject_start(ii_dev); + } else if (current_state > 0 && !state) { + idle_inject_stop(ii_dev); + } + + return 0; +} + +/** + * cpuidle_cooling_ops - thermal cooling device ops + */ +static struct thermal_cooling_device_ops cpuidle_cooling_ops = { + .get_max_state = cpuidle_cooling_get_max_state, + .get_cur_state = cpuidle_cooling_get_cur_state, + .set_cur_state = cpuidle_cooling_set_cur_state, +}; + +/** + * __cpuidle_cooling_register: register the cooling device + * @drv: a cpuidle driver structure pointer + * @np: a device node structure pointer used for the thermal binding + * + * This function is in charge of allocating the cpuidle cooling device + * structure, the idle injection, initialize them and register the + * cooling device to the thermal framework. + * + * Return: zero on success, a negative value returned by one of the + * underlying subsystem in case of error + */ +static int __cpuidle_cooling_register(struct device_node *np, + struct cpuidle_driver *drv) +{ + struct idle_inject_device *ii_dev; + struct cpuidle_cooling_device *idle_cdev; + struct thermal_cooling_device *cdev; + struct device *dev; + unsigned int idle_duration_us = TICK_USEC; + unsigned int latency_us = UINT_MAX; + char *name; + int ret; + + idle_cdev = kzalloc(sizeof(*idle_cdev), GFP_KERNEL); + if (!idle_cdev) { + ret = -ENOMEM; + goto out; + } + + ii_dev = idle_inject_register(drv->cpumask); + if (!ii_dev) { + ret = -EINVAL; + goto out_kfree; + } + + of_property_read_u32(np, "duration-us", &idle_duration_us); + of_property_read_u32(np, "exit-latency-us", &latency_us); + + idle_inject_set_duration(ii_dev, TICK_USEC, idle_duration_us); + idle_inject_set_latency(ii_dev, latency_us); + + idle_cdev->ii_dev = ii_dev; + + dev = get_cpu_device(cpumask_first(drv->cpumask)); + + name = kasprintf(GFP_KERNEL, "idle-%s", dev_name(dev)); + if (!name) { + ret = -ENOMEM; + goto out_unregister; + } + + cdev = thermal_of_cooling_device_register(np, name, idle_cdev, + &cpuidle_cooling_ops); + if (IS_ERR(cdev)) { + ret = PTR_ERR(cdev); + goto out_kfree_name; + } + + pr_debug("%s: Idle injection set with idle duration=%u, latency=%u\n", + name, idle_duration_us, latency_us); + + kfree(name); + + return 0; + +out_kfree_name: + kfree(name); +out_unregister: + idle_inject_unregister(ii_dev); +out_kfree: + kfree(idle_cdev); +out: + return ret; +} + +/** + * cpuidle_cooling_register - Idle cooling device initialization function + * @drv: a cpuidle driver structure pointer + * + * This function is in charge of creating a cooling device per cpuidle + * driver and register it to the thermal framework. + */ +void cpuidle_cooling_register(struct cpuidle_driver *drv) +{ + struct device_node *cooling_node; + struct device_node *cpu_node; + int cpu, ret; + + for_each_cpu(cpu, drv->cpumask) { + + cpu_node = of_cpu_device_node_get(cpu); + + cooling_node = of_get_child_by_name(cpu_node, "thermal-idle"); + + of_node_put(cpu_node); + + if (!cooling_node) { + pr_debug("'thermal-idle' node not found for cpu%d\n", cpu); + continue; + } + + ret = __cpuidle_cooling_register(cooling_node, drv); + + of_node_put(cooling_node); + + if (ret) { + pr_err("Failed to register the cpuidle cooling device" \ + "for cpu%d: %d\n", cpu, ret); + break; + } + } +} -- cgit v1.2.3