diff options
| -rw-r--r-- | drivers/base/power/Makefile | 4 | ||||
| -rw-r--r-- | drivers/base/power/main.c | 3 | ||||
| -rw-r--r-- | drivers/base/power/qos.c | 338 | ||||
| -rw-r--r-- | include/linux/pm.h | 9 | ||||
| -rw-r--r-- | include/linux/pm_qos.h | 42 |
5 files changed, 394 insertions, 2 deletions
diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile index 6488ce12f58..81676dd1790 100644 --- a/drivers/base/power/Makefile +++ b/drivers/base/power/Makefile @@ -1,4 +1,4 @@ -obj-$(CONFIG_PM) += sysfs.o generic_ops.o common.o +obj-$(CONFIG_PM) += sysfs.o generic_ops.o common.o qos.o obj-$(CONFIG_PM_SLEEP) += main.o wakeup.o obj-$(CONFIG_PM_RUNTIME) += runtime.o obj-$(CONFIG_PM_TRACE_RTC) += trace.o @@ -6,4 +6,4 @@ obj-$(CONFIG_PM_OPP) += opp.o obj-$(CONFIG_PM_GENERIC_DOMAINS) += domain.o obj-$(CONFIG_HAVE_CLK) += clock_ops.o -ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
\ No newline at end of file +ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index a85459126bc..956443f8625 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -22,6 +22,7 @@ #include <linux/mutex.h> #include <linux/pm.h> #include <linux/pm_runtime.h> +#include <linux/pm_qos.h> #include <linux/resume-trace.h> #include <linux/interrupt.h> #include <linux/sched.h> @@ -97,6 +98,7 @@ void device_pm_add(struct device *dev) dev_name(dev->parent)); list_add_tail(&dev->power.entry, &dpm_list); mutex_unlock(&dpm_list_mtx); + dev_pm_qos_constraints_init(dev); } /** @@ -107,6 +109,7 @@ void device_pm_remove(struct device *dev) { pr_debug("PM: Removing info for %s:%s\n", dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); + dev_pm_qos_constraints_destroy(dev); complete_all(&dev->power.completion); mutex_lock(&dpm_list_mtx); list_del_init(&dev->power.entry); diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c new file mode 100644 index 00000000000..cc4c541398a --- /dev/null +++ b/drivers/base/power/qos.c @@ -0,0 +1,338 @@ +/* + * Devices PM QoS constraints management + * + * Copyright (C) 2011 Texas Instruments, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * + * This module exposes the interface to kernel space for specifying + * per-device PM QoS dependencies. It provides infrastructure for registration + * of: + * + * Dependents on a QoS value : register requests + * Watchers of QoS value : get notified when target QoS value changes + * + * This QoS design is best effort based. Dependents register their QoS needs. + * Watchers register to keep track of the current QoS needs of the system. + * + * Note about the per-device constraint data struct allocation: + * . The per-device constraints data struct ptr is tored into the device + * dev_pm_info. + * . To minimize the data usage by the per-device constraints, the data struct + * is only allocated at the first call to dev_pm_qos_add_request. + * . The data is later free'd when the device is removed from the system. + * . The constraints_state variable from dev_pm_info tracks the data struct + * allocation state: + * DEV_PM_QOS_NO_DEVICE: No device present or device removed, no data + * allocated, + * DEV_PM_QOS_DEVICE_PRESENT: Device present, data not allocated and will be + * allocated at the first call to dev_pm_qos_add_request, + * DEV_PM_QOS_ALLOCATED: Device present, data allocated. The per-device + * PM QoS constraints framework is operational and constraints can be + * added, updated or removed using the dev_pm_qos_* API. + * . A global mutex protects the constraints users from the data being + * allocated and free'd. + */ + +#include <linux/pm_qos.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/device.h> +#include <linux/mutex.h> + + +static DEFINE_MUTEX(dev_pm_qos_mtx); + +/* + * dev_pm_qos_constraints_allocate + * @dev: device to allocate data for + * + * Called at the first call to add_request, for constraint data allocation + * Must be called with the dev_pm_qos_mtx mutex held + */ +static int dev_pm_qos_constraints_allocate(struct device *dev) +{ + struct pm_qos_constraints *c; + struct blocking_notifier_head *n; + + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + n = kzalloc(sizeof(*n), GFP_KERNEL); + if (!n) { + kfree(c); + return -ENOMEM; + } + BLOCKING_INIT_NOTIFIER_HEAD(n); + + dev->power.constraints = c; + plist_head_init(&dev->power.constraints->list); + dev->power.constraints->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; + dev->power.constraints->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; + dev->power.constraints->type = PM_QOS_MIN; + dev->power.constraints->notifiers = n; + dev->power.constraints_state = DEV_PM_QOS_ALLOCATED; + + return 0; +} + +/** + * dev_pm_qos_constraints_init + * @dev: target device + * + * Called from the device PM subsystem at device insertion + */ +void dev_pm_qos_constraints_init(struct device *dev) +{ + mutex_lock(&dev_pm_qos_mtx); + dev->power.constraints_state = DEV_PM_QOS_DEVICE_PRESENT; + mutex_unlock(&dev_pm_qos_mtx); +} + +/** + * dev_pm_qos_constraints_destroy + * @dev: target device + * + * Called from the device PM subsystem at device removal + */ +void dev_pm_qos_constraints_destroy(struct device *dev) +{ + struct dev_pm_qos_request *req, *tmp; + + mutex_lock(&dev_pm_qos_mtx); + + if (dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + /* Flush the constraints list for the device */ + plist_for_each_entry_safe(req, tmp, + &dev->power.constraints->list, + node) { + /* + * Update constraints list and call the per-device + * callbacks if needed + */ + pm_qos_update_target(req->dev->power.constraints, + &req->node, PM_QOS_REMOVE_REQ, + PM_QOS_DEFAULT_VALUE); + memset(req, 0, sizeof(*req)); + } + + kfree(dev->power.constraints->notifiers); + kfree(dev->power.constraints); + dev->power.constraints = NULL; + } + dev->power.constraints_state = DEV_PM_QOS_NO_DEVICE; + + mutex_unlock(&dev_pm_qos_mtx); +} + +/** + * dev_pm_qos_add_request - inserts new qos request into the list + * @dev: target device for the constraint + * @req: pointer to a preallocated handle + * @value: defines the qos request + * + * This function inserts a new entry in the device constraints list of + * requested qos performance characteristics. It recomputes the aggregate + * QoS expectations of parameters and initializes the dev_pm_qos_request + * handle. Caller needs to save this handle for later use in updates and + * removal. + * + * Returns 1 if the aggregated constraint value has changed, + * 0 if the aggregated constraint value has not changed, + * -EINVAL in case of wrong parameters, -ENODEV if the device has been + * removed from the system + */ +int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, + s32 value) +{ + int ret = 0; + + if (!dev || !req) /*guard against callers passing in null */ + return -EINVAL; + + if (dev_pm_qos_request_active(req)) { + WARN(1, KERN_ERR "dev_pm_qos_add_request() called for already " + "added request\n"); + return -EINVAL; + } + + mutex_lock(&dev_pm_qos_mtx); + req->dev = dev; + + /* Return if the device has been removed */ + if (req->dev->power.constraints_state == DEV_PM_QOS_NO_DEVICE) { + ret = -ENODEV; + goto out; + } + + /* + * Allocate the constraints data on the first call to add_request, + * i.e. only if the data is not already allocated and if the device has + * not been removed + */ + if (dev->power.constraints_state == DEV_PM_QOS_DEVICE_PRESENT) + ret = dev_pm_qos_constraints_allocate(dev); + + if (!ret) + ret = pm_qos_update_target(dev->power.constraints, &req->node, + PM_QOS_ADD_REQ, value); + +out: + mutex_unlock(&dev_pm_qos_mtx); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_add_request); + +/** + * dev_pm_qos_update_request - modifies an existing qos request + * @req : handle to list element holding a dev_pm_qos request to use + * @new_value: defines the qos request + * + * Updates an existing dev PM qos request along with updating the + * target value. + * + * Attempts are made to make this code callable on hot code paths. + * + * Returns 1 if the aggregated constraint value has changed, + * 0 if the aggregated constraint value has not changed, + * -EINVAL in case of wrong parameters, -ENODEV if the device has been + * removed from the system + */ +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, + s32 new_value) +{ + int ret = 0; + + if (!req) /*guard against callers passing in null */ + return -EINVAL; + + if (!dev_pm_qos_request_active(req)) { + WARN(1, KERN_ERR "dev_pm_qos_update_request() called for " + "unknown object\n"); + return -EINVAL; + } + + mutex_lock(&dev_pm_qos_mtx); + + if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + if (new_value != req->node.prio) + ret = pm_qos_update_target(req->dev->power.constraints, + &req->node, + PM_QOS_UPDATE_REQ, + new_value); + } else { + /* Return if the device has been removed */ + ret = -ENODEV; + } + + mutex_unlock(&dev_pm_qos_mtx); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_update_request); + +/** + * dev_pm_qos_remove_request - modifies an existing qos request + * @req: handle to request list element + * + * Will remove pm qos request from the list of constraints and + * recompute the current target value. Call this on slow code paths. + * + * Returns 1 if the aggregated constraint value has changed, + * 0 if the aggregated constraint value has not changed, + * -EINVAL in case of wrong parameters, -ENODEV if the device has been + * removed from the system + */ +int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) +{ + int ret = 0; + + if (!req) /*guard against callers passing in null */ + return -EINVAL; + + if (!dev_pm_qos_request_active(req)) { + WARN(1, KERN_ERR "dev_pm_qos_remove_request() called for " + "unknown object\n"); + return -EINVAL; + } + + mutex_lock(&dev_pm_qos_mtx); + + if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + ret = pm_qos_update_target(req->dev->power.constraints, + &req->node, PM_QOS_REMOVE_REQ, + PM_QOS_DEFAULT_VALUE); + memset(req, 0, sizeof(*req)); + } else { + /* Return if the device has been removed */ + ret = -ENODEV; + } + + mutex_unlock(&dev_pm_qos_mtx); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request); + +/** + * dev_pm_qos_add_notifier - sets notification entry for changes to target value + * of per-device PM QoS constraints + * + * @dev: target device for the constraint + * @notifier: notifier block managed by caller. + * + * Will register the notifier into a notification chain that gets called + * upon changes to the target value for the device. + */ +int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier) +{ + int retval = 0; + + mutex_lock(&dev_pm_qos_mtx); + + /* Silently return if the device has been removed */ + if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED) + goto out; + + retval = blocking_notifier_chain_register( + dev->power.constraints->notifiers, + notifier); + +out: + mutex_unlock(&dev_pm_qos_mtx); + return retval; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier); + +/** + * dev_pm_qos_remove_notifier - deletes notification for changes to target value + * of per-device PM QoS constraints + * + * @dev: target device for the constraint + * @notifier: notifier block to be removed. + * + * Will remove the notifier from the notification chain that gets called + * upon changes to the target value. + */ +int dev_pm_qos_remove_notifier(struct device *dev, + struct notifier_block *notifier) +{ + int retval = 0; + + mutex_lock(&dev_pm_qos_mtx); + + /* Silently return if the device has been removed */ + if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED) + goto out; + + retval = blocking_notifier_chain_unregister( + dev->power.constraints->notifiers, + notifier); + +out: + mutex_unlock(&dev_pm_qos_mtx); + return retval; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier); diff --git a/include/linux/pm.h b/include/linux/pm.h index ed10f24d525..d78187e9ca9 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -419,6 +419,13 @@ enum rpm_request { RPM_REQ_RESUME, }; +/* Per-device PM QoS constraints data struct state */ +enum dev_pm_qos_state { + DEV_PM_QOS_NO_DEVICE, /* No device present */ + DEV_PM_QOS_DEVICE_PRESENT, /* Device present, data not allocated */ + DEV_PM_QOS_ALLOCATED, /* Device present, data allocated */ +}; + struct wakeup_source; struct pm_domain_data { @@ -480,6 +487,8 @@ struct dev_pm_info { unsigned long accounting_timestamp; #endif struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */ + struct pm_qos_constraints *constraints; + enum dev_pm_qos_state constraints_state; }; extern void update_pm_runtime_accounting(struct device *dev); diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 84aa1508989..f75f74dd9b9 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -19,12 +19,18 @@ #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0 +#define PM_QOS_DEV_LAT_DEFAULT_VALUE 0 struct pm_qos_request { struct plist_node node; int pm_qos_class; }; +struct dev_pm_qos_request { + struct plist_node node; + struct device *dev; +}; + enum pm_qos_type { PM_QOS_UNITIALIZED, PM_QOS_MAX, /* return the largest value */ @@ -51,6 +57,11 @@ enum pm_qos_req_action { PM_QOS_REMOVE_REQ /* Remove an existing request */ }; +static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req) +{ + return req->dev != 0; +} + #ifdef CONFIG_PM int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, enum pm_qos_req_action action, int value); @@ -64,6 +75,17 @@ int pm_qos_request(int pm_qos_class); int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_request_active(struct pm_qos_request *req); + +int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, + s32 value); +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value); +int dev_pm_qos_remove_request(struct dev_pm_qos_request *req); +int dev_pm_qos_add_notifier(struct device *dev, + struct notifier_block *notifier); +int dev_pm_qos_remove_notifier(struct device *dev, + struct notifier_block *notifier); +void dev_pm_qos_constraints_init(struct device *dev); +void dev_pm_qos_constraints_destroy(struct device *dev); #else static inline int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, @@ -89,6 +111,26 @@ static inline int pm_qos_remove_notifier(int pm_qos_class, { return 0; } static inline int pm_qos_request_active(struct pm_qos_request *req) { return 0; } + +static inline int dev_pm_qos_add_request(struct device *dev, + struct dev_pm_qos_request *req, + s32 value) + { return 0; } +static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req, + s32 new_value) + { return 0; } +static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) + { return 0; } +static inline int dev_pm_qos_add_notifier(struct device *dev, + struct notifier_block *notifier) + { return 0; } +static inline int dev_pm_qos_remove_notifier(struct device *dev, + struct notifier_block *notifier) + { return 0; } +static inline void dev_pm_qos_constraints_init(struct device *dev) + { return; } +static inline void dev_pm_qos_constraints_destroy(struct device *dev) + { return; } #endif #endif |