diff options
| -rw-r--r-- | drivers/powercap/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/powercap/Makefile | 1 | ||||
| -rw-r--r-- | drivers/powercap/dtpm.c | 473 | ||||
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 11 | ||||
| -rw-r--r-- | include/linux/dtpm.h | 75 |
5 files changed, 566 insertions, 0 deletions
diff --git a/drivers/powercap/Kconfig b/drivers/powercap/Kconfig index bc228725346b..cc1953bd8bed 100644 --- a/drivers/powercap/Kconfig +++ b/drivers/powercap/Kconfig @@ -43,4 +43,10 @@ config IDLE_INJECT CPUs for power capping. Idle period can be injected synchronously on a set of specified CPUs or alternatively on a per CPU basis. + +config DTPM + bool "Power capping for Dynamic Thermal Power Management" + help + This enables support for the power capping for the dynamic + thermal power management userspace engine. endif diff --git a/drivers/powercap/Makefile b/drivers/powercap/Makefile index 7255c94ec61c..6482ac52054d 100644 --- a/drivers/powercap/Makefile +++ b/drivers/powercap/Makefile @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_DTPM) += dtpm.o obj-$(CONFIG_POWERCAP) += powercap_sys.o obj-$(CONFIG_INTEL_RAPL_CORE) += intel_rapl_common.o obj-$(CONFIG_INTEL_RAPL) += intel_rapl_msr.o diff --git a/drivers/powercap/dtpm.c b/drivers/powercap/dtpm.c new file mode 100644 index 000000000000..5b6857e9b064 --- /dev/null +++ b/drivers/powercap/dtpm.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2020 Linaro Limited + * + * Author: Daniel Lezcano <daniel.lezcano@linaro.org> + * + * The powercap based Dynamic Thermal Power Management framework + * provides to the userspace a consistent API to set the power limit + * on some devices. + * + * DTPM defines the functions to create a tree of constraints. Each + * parent node is a virtual description of the aggregation of the + * children. It propagates the constraints set at its level to its + * children and collect the children power information. The leaves of + * the tree are the real devices which have the ability to get their + * current power consumption and set their power limit. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/dtpm.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/powercap.h> +#include <linux/slab.h> +#include <linux/mutex.h> + +#define DTPM_POWER_LIMIT_FLAG BIT(0) + +static const char *constraint_name[] = { + "Instantaneous", +}; + +static DEFINE_MUTEX(dtpm_lock); +static struct powercap_control_type *pct; +static struct dtpm *root; + +static int get_time_window_us(struct powercap_zone *pcz, int cid, u64 *window) +{ + return -ENOSYS; +} + +static int set_time_window_us(struct powercap_zone *pcz, int cid, u64 window) +{ + return -ENOSYS; +} + +static int get_max_power_range_uw(struct powercap_zone *pcz, u64 *max_power_uw) +{ + struct dtpm *dtpm = to_dtpm(pcz); + + mutex_lock(&dtpm_lock); + *max_power_uw = dtpm->power_max - dtpm->power_min; + mutex_unlock(&dtpm_lock); + + return 0; +} + +static int __get_power_uw(struct dtpm *dtpm, u64 *power_uw) +{ + struct dtpm *child; + u64 power; + int ret = 0; + + if (dtpm->ops) { + *power_uw = dtpm->ops->get_power_uw(dtpm); + return 0; + } + + *power_uw = 0; + + list_for_each_entry(child, &dtpm->children, sibling) { + ret = __get_power_uw(child, &power); + if (ret) + break; + *power_uw += power; + } + + return ret; +} + +static int get_power_uw(struct powercap_zone *pcz, u64 *power_uw) +{ + struct dtpm *dtpm = to_dtpm(pcz); + int ret; + + mutex_lock(&dtpm_lock); + ret = __get_power_uw(dtpm, power_uw); + mutex_unlock(&dtpm_lock); + + return ret; +} + +static void __dtpm_rebalance_weight(struct dtpm *dtpm) +{ + struct dtpm *child; + + list_for_each_entry(child, &dtpm->children, sibling) { + + pr_debug("Setting weight '%d' for '%s'\n", + child->weight, child->zone.name); + + child->weight = DIV_ROUND_CLOSEST(child->power_max * 1024, + dtpm->power_max); + + __dtpm_rebalance_weight(child); + } +} + +static void __dtpm_sub_power(struct dtpm *dtpm) +{ + struct dtpm *parent = dtpm->parent; + + while (parent) { + parent->power_min -= dtpm->power_min; + parent->power_max -= dtpm->power_max; + parent->power_limit -= dtpm->power_limit; + parent = parent->parent; + } + + __dtpm_rebalance_weight(root); +} + +static void __dtpm_add_power(struct dtpm *dtpm) +{ + struct dtpm *parent = dtpm->parent; + + while (parent) { + parent->power_min += dtpm->power_min; + parent->power_max += dtpm->power_max; + parent->power_limit += dtpm->power_limit; + parent = parent->parent; + } + + __dtpm_rebalance_weight(root); +} + +/** + * dtpm_update_power - Update the power on the dtpm + * @dtpm: a pointer to a dtpm structure to update + * @power_min: a u64 representing the new power_min value + * @power_max: a u64 representing the new power_max value + * + * Function to update the power values of the dtpm node specified in + * parameter. These new values will be propagated to the tree. + * + * Return: zero on success, -EINVAL if the values are inconsistent + */ +int dtpm_update_power(struct dtpm *dtpm, u64 power_min, u64 power_max) +{ + mutex_lock(&dtpm_lock); + + if (power_min == dtpm->power_min && power_max == dtpm->power_max) + return 0; + + if (power_max < power_min) + return -EINVAL; + + __dtpm_sub_power(dtpm); + + dtpm->power_min = power_min; + dtpm->power_max = power_max; + if (!test_bit(DTPM_POWER_LIMIT_FLAG, &dtpm->flags)) + dtpm->power_limit = power_max; + + __dtpm_add_power(dtpm); + + mutex_unlock(&dtpm_lock); + + return 0; +} + +/** + * dtpm_release_zone - Cleanup when the node is released + * @pcz: a pointer to a powercap_zone structure + * + * Do some housecleaning and update the weight on the tree. The + * release will be denied if the node has children. This function must + * be called by the specific release callback of the different + * backends. + * + * Return: 0 on success, -EBUSY if there are children + */ +int dtpm_release_zone(struct powercap_zone *pcz) +{ + struct dtpm *dtpm = to_dtpm(pcz); + struct dtpm *parent = dtpm->parent; + + mutex_lock(&dtpm_lock); + + if (!list_empty(&dtpm->children)) + return -EBUSY; + + if (parent) + list_del(&dtpm->sibling); + + __dtpm_sub_power(dtpm); + + mutex_unlock(&dtpm_lock); + + if (dtpm->ops) + dtpm->ops->release(dtpm); + + kfree(dtpm); + + return 0; +} + +static int __get_power_limit_uw(struct dtpm *dtpm, int cid, u64 *power_limit) +{ + *power_limit = dtpm->power_limit; + return 0; +} + +static int get_power_limit_uw(struct powercap_zone *pcz, + int cid, u64 *power_limit) +{ + struct dtpm *dtpm = to_dtpm(pcz); + int ret; + + mutex_lock(&dtpm_lock); + ret = __get_power_limit_uw(dtpm, cid, power_limit); + mutex_unlock(&dtpm_lock); + + return ret; +} + +/* + * Set the power limit on the nodes, the power limit is distributed + * given the weight of the children. + * + * The dtpm node lock must be held when calling this function. + */ +static int __set_power_limit_uw(struct dtpm *dtpm, int cid, u64 power_limit) +{ + struct dtpm *child; + int ret = 0; + u64 power; + + /* + * A max power limitation means we remove the power limit, + * otherwise we set a constraint and flag the dtpm node. + */ + if (power_limit == dtpm->power_max) { + clear_bit(DTPM_POWER_LIMIT_FLAG, &dtpm->flags); + } else { + set_bit(DTPM_POWER_LIMIT_FLAG, &dtpm->flags); + } + + pr_debug("Setting power limit for '%s': %llu uW\n", + dtpm->zone.name, power_limit); + + /* + * Only leaves of the dtpm tree has ops to get/set the power + */ + if (dtpm->ops) { + dtpm->power_limit = dtpm->ops->set_power_uw(dtpm, power_limit); + } else { + dtpm->power_limit = 0; + + list_for_each_entry(child, &dtpm->children, sibling) { + + /* + * Integer division rounding will inevitably + * lead to a different min or max value when + * set several times. In order to restore the + * initial value, we force the child's min or + * max power every time if the constraint is + * at the boundaries. + */ + if (power_limit == dtpm->power_max) { + power = child->power_max; + } else if (power_limit == dtpm->power_min) { + power = child->power_min; + } else { + power = DIV_ROUND_CLOSEST( + power_limit * child->weight, 1024); + } + + pr_debug("Setting power limit for '%s': %llu uW\n", + child->zone.name, power); + + ret = __set_power_limit_uw(child, cid, power); + if (!ret) + ret = __get_power_limit_uw(child, cid, &power); + + if (ret) + break; + + dtpm->power_limit += power; + } + } + + return ret; +} + +static int set_power_limit_uw(struct powercap_zone *pcz, + int cid, u64 power_limit) +{ + struct dtpm *dtpm = to_dtpm(pcz); + int ret; + + mutex_lock(&dtpm_lock); + + /* + * Don't allow values outside of the power range previously + * set when initializing the power numbers. + */ + power_limit = clamp_val(power_limit, dtpm->power_min, dtpm->power_max); + + ret = __set_power_limit_uw(dtpm, cid, power_limit); + + pr_debug("%s: power limit: %llu uW, power max: %llu uW\n", + dtpm->zone.name, dtpm->power_limit, dtpm->power_max); + + mutex_unlock(&dtpm_lock); + + return ret; +} + +static const char *get_constraint_name(struct powercap_zone *pcz, int cid) +{ + return constraint_name[cid]; +} + +static int get_max_power_uw(struct powercap_zone *pcz, int id, u64 *max_power) +{ + struct dtpm *dtpm = to_dtpm(pcz); + + mutex_lock(&dtpm_lock); + *max_power = dtpm->power_max; + mutex_unlock(&dtpm_lock); + + return 0; +} + +static struct powercap_zone_constraint_ops constraint_ops = { + .set_power_limit_uw = set_power_limit_uw, + .get_power_limit_uw = get_power_limit_uw, + .set_time_window_us = set_time_window_us, + .get_time_window_us = get_time_window_us, + .get_max_power_uw = get_max_power_uw, + .get_name = get_constraint_name, +}; + +static struct powercap_zone_ops zone_ops = { + .get_max_power_range_uw = get_max_power_range_uw, + .get_power_uw = get_power_uw, + .release = dtpm_release_zone, +}; + +/** + * dtpm_alloc - Allocate and initialize a dtpm struct + * @name: a string specifying the name of the node + * + * Return: a struct dtpm pointer, NULL in case of error + */ +struct dtpm *dtpm_alloc(struct dtpm_ops *ops) +{ + struct dtpm *dtpm; + + dtpm = kzalloc(sizeof(*dtpm), GFP_KERNEL); + if (dtpm) { + INIT_LIST_HEAD(&dtpm->children); + INIT_LIST_HEAD(&dtpm->sibling); + dtpm->weight = 1024; + dtpm->ops = ops; + } + + return dtpm; +} + +/** + * dtpm_unregister - Unregister a dtpm node from the hierarchy tree + * @dtpm: a pointer to a dtpm structure corresponding to the node to be removed + * + * Call the underlying powercap unregister function. That will call + * the release callback of the powercap zone. + */ +void dtpm_unregister(struct dtpm *dtpm) +{ + powercap_unregister_zone(pct, &dtpm->zone); + + pr_info("Unregistered dtpm node '%s'\n", dtpm->zone.name); +} + +/** + * dtpm_register - Register a dtpm node in the hierarchy tree + * @name: a string specifying the name of the node + * @dtpm: a pointer to a dtpm structure corresponding to the new node + * @parent: a pointer to a dtpm structure corresponding to the parent node + * + * Create a dtpm node in the tree. If no parent is specified, the node + * is the root node of the hierarchy. If the root node already exists, + * then the registration will fail. The powercap controller must be + * initialized before calling this function. + * + * The dtpm structure must be initialized with the power numbers + * before calling this function. + * + * Return: zero on success, a negative value in case of error: + * -EAGAIN: the function is called before the framework is initialized. + * -EBUSY: the root node is already inserted + * -EINVAL: * there is no root node yet and @parent is specified + * * no all ops are defined + * * parent have ops which are reserved for leaves + * Other negative values are reported back from the powercap framework + */ +int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent) +{ + struct powercap_zone *pcz; + + if (!pct) + return -EAGAIN; + + if (root && !parent) + return -EBUSY; + + if (!root && parent) + return -EINVAL; + + if (parent && parent->ops) + return -EINVAL; + + if (!dtpm) + return -EINVAL; + + if (dtpm->ops && !(dtpm->ops->set_power_uw && + dtpm->ops->get_power_uw && + dtpm->ops->release)) + return -EINVAL; + + pcz = powercap_register_zone(&dtpm->zone, pct, name, + parent ? &parent->zone : NULL, + &zone_ops, MAX_DTPM_CONSTRAINTS, + &constraint_ops); + if (IS_ERR(pcz)) + return PTR_ERR(pcz); + + mutex_lock(&dtpm_lock); + + if (parent) { + list_add_tail(&dtpm->sibling, &parent->children); + dtpm->parent = parent; + } else { + root = dtpm; + } + + __dtpm_add_power(dtpm); + + pr_info("Registered dtpm node '%s' / %llu-%llu uW, \n", + dtpm->zone.name, dtpm->power_min, dtpm->power_max); + + mutex_unlock(&dtpm_lock); + + return 0; +} + +static int __init dtpm_init(void) +{ + struct dtpm_descr **dtpm_descr; + + pct = powercap_register_control_type(NULL, "dtpm", NULL); + if (!pct) { + pr_err("Failed to register control type\n"); + return -EINVAL; + } + + for_each_dtpm_table(dtpm_descr) + (*dtpm_descr)->init(*dtpm_descr); + + return 0; +} +late_initcall(dtpm_init); diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index b2b3d81b1535..b3e4e0740089 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -316,6 +316,16 @@ #define THERMAL_TABLE(name) #endif +#ifdef CONFIG_DTPM +#define DTPM_TABLE() \ + . = ALIGN(8); \ + __dtpm_table = .; \ + KEEP(*(__dtpm_table)) \ + __dtpm_table_end = .; +#else +#define DTPM_TABLE() +#endif + #define KERNEL_DTB() \ STRUCT_ALIGN(); \ __dtb_start = .; \ @@ -733,6 +743,7 @@ ACPI_PROBE_TABLE(irqchip) \ ACPI_PROBE_TABLE(timer) \ THERMAL_TABLE(governor) \ + DTPM_TABLE() \ EARLYCON_TABLE() \ LSM_TABLE() \ EARLY_LSM_TABLE() \ diff --git a/include/linux/dtpm.h b/include/linux/dtpm.h new file mode 100644 index 000000000000..7a1d0b50e334 --- /dev/null +++ b/include/linux/dtpm.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 Linaro Ltd + * + * Author: Daniel Lezcano <daniel.lezcano@linaro.org> + */ +#ifndef ___DTPM_H__ +#define ___DTPM_H__ + +#include <linux/powercap.h> + +#define MAX_DTPM_DESCR 8 +#define MAX_DTPM_CONSTRAINTS 1 + +struct dtpm { + struct powercap_zone zone; + struct dtpm *parent; + struct list_head sibling; + struct list_head children; + struct dtpm_ops *ops; + unsigned long flags; + u64 power_limit; + u64 power_max; + u64 power_min; + int weight; + void *private; +}; + +struct dtpm_ops { + u64 (*set_power_uw)(struct dtpm *, u64); + u64 (*get_power_uw)(struct dtpm *); + void (*release)(struct dtpm *); +}; + +struct dtpm_descr; + +typedef int (*dtpm_init_t)(struct dtpm_descr *); + +struct dtpm_descr { + struct dtpm *parent; + const char *name; + dtpm_init_t init; +}; + +/* Init section thermal table */ +extern struct dtpm_descr *__dtpm_table[]; +extern struct dtpm_descr *__dtpm_table_end[]; + +#define DTPM_TABLE_ENTRY(name) \ + static typeof(name) *__dtpm_table_entry_##name \ + __used __section("__dtpm_table") = &name + +#define DTPM_DECLARE(name) DTPM_TABLE_ENTRY(name) + +#define for_each_dtpm_table(__dtpm) \ + for (__dtpm = __dtpm_table; \ + __dtpm < __dtpm_table_end; \ + __dtpm++) + +static inline struct dtpm *to_dtpm(struct powercap_zone *zone) +{ + return container_of(zone, struct dtpm, zone); +} + +int dtpm_update_power(struct dtpm *dtpm, u64 power_min, u64 power_max); + +int dtpm_release_zone(struct powercap_zone *pcz); + +struct dtpm *dtpm_alloc(struct dtpm_ops *ops); + +void dtpm_unregister(struct dtpm *dtpm); + +int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent); + +#endif |