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authorJean Pihet2011-08-25 15:35:03 +0200
committerRafael J. Wysocki2011-08-25 15:35:03 +0200
commite8db0be1245de16a6cc6365506abc392c3c212d4 (patch)
tree01cf446568080c06c8797262554f3b0f758ae137 /kernel/pm_qos_params.c
parentPM: Move clock-related definitions and headers to separate file (diff)
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PM QoS: Move and rename the implementation files
The PM QoS implementation files are better named kernel/power/qos.c and include/linux/pm_qos.h. The PM QoS support is compiled under the CONFIG_PM option. Signed-off-by: Jean Pihet <j-pihet@ti.com> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'kernel/pm_qos_params.c')
-rw-r--r--kernel/pm_qos_params.c481
1 files changed, 0 insertions, 481 deletions
diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
deleted file mode 100644
index 37f05d0f0793..000000000000
--- a/kernel/pm_qos_params.c
+++ /dev/null
@@ -1,481 +0,0 @@
-/*
- * This module exposes the interface to kernel space for specifying
- * 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.
- *
- * There are 3 basic classes of QoS parameter: latency, timeout, throughput
- * each have defined units:
- * latency: usec
- * timeout: usec <-- currently not used.
- * throughput: kbs (kilo byte / sec)
- *
- * There are lists of pm_qos_objects each one wrapping requests, notifiers
- *
- * User mode requests on a QOS parameter register themselves to the
- * subsystem by opening the device node /dev/... and writing there request to
- * the node. As long as the process holds a file handle open to the node the
- * client continues to be accounted for. Upon file release the usermode
- * request is removed and a new qos target is computed. This way when the
- * request that the application has is cleaned up when closes the file
- * pointer or exits the pm_qos_object will get an opportunity to clean up.
- *
- * Mark Gross <mgross@linux.intel.com>
- */
-
-/*#define DEBUG*/
-
-#include <linux/pm_qos_params.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <linux/slab.h>
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/device.h>
-#include <linux/miscdevice.h>
-#include <linux/string.h>
-#include <linux/platform_device.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-
-#include <linux/uaccess.h>
-
-/*
- * locking rule: all changes to requests or notifiers lists
- * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
- * held, taken with _irqsave. One lock to rule them all
- */
-enum pm_qos_type {
- PM_QOS_MAX, /* return the largest value */
- PM_QOS_MIN /* return the smallest value */
-};
-
-/*
- * Note: The lockless read path depends on the CPU accessing
- * target_value atomically. Atomic access is only guaranteed on all CPU
- * types linux supports for 32 bit quantites
- */
-struct pm_qos_object {
- struct plist_head requests;
- struct blocking_notifier_head *notifiers;
- struct miscdevice pm_qos_power_miscdev;
- char *name;
- s32 target_value; /* Do not change to 64 bit */
- s32 default_value;
- enum pm_qos_type type;
-};
-
-static DEFINE_SPINLOCK(pm_qos_lock);
-
-static struct pm_qos_object null_pm_qos;
-static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
-static struct pm_qos_object cpu_dma_pm_qos = {
- .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests),
- .notifiers = &cpu_dma_lat_notifier,
- .name = "cpu_dma_latency",
- .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
- .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
- .type = PM_QOS_MIN,
-};
-
-static BLOCKING_NOTIFIER_HEAD(network_lat_notifier);
-static struct pm_qos_object network_lat_pm_qos = {
- .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests),
- .notifiers = &network_lat_notifier,
- .name = "network_latency",
- .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
- .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
- .type = PM_QOS_MIN
-};
-
-
-static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier);
-static struct pm_qos_object network_throughput_pm_qos = {
- .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests),
- .notifiers = &network_throughput_notifier,
- .name = "network_throughput",
- .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
- .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
- .type = PM_QOS_MAX,
-};
-
-
-static struct pm_qos_object *pm_qos_array[] = {
- &null_pm_qos,
- &cpu_dma_pm_qos,
- &network_lat_pm_qos,
- &network_throughput_pm_qos
-};
-
-static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
- size_t count, loff_t *f_pos);
-static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
- size_t count, loff_t *f_pos);
-static int pm_qos_power_open(struct inode *inode, struct file *filp);
-static int pm_qos_power_release(struct inode *inode, struct file *filp);
-
-static const struct file_operations pm_qos_power_fops = {
- .write = pm_qos_power_write,
- .read = pm_qos_power_read,
- .open = pm_qos_power_open,
- .release = pm_qos_power_release,
- .llseek = noop_llseek,
-};
-
-/* unlocked internal variant */
-static inline int pm_qos_get_value(struct pm_qos_object *o)
-{
- if (plist_head_empty(&o->requests))
- return o->default_value;
-
- switch (o->type) {
- case PM_QOS_MIN:
- return plist_first(&o->requests)->prio;
-
- case PM_QOS_MAX:
- return plist_last(&o->requests)->prio;
-
- default:
- /* runtime check for not using enum */
- BUG();
- }
-}
-
-static inline s32 pm_qos_read_value(struct pm_qos_object *o)
-{
- return o->target_value;
-}
-
-static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value)
-{
- o->target_value = value;
-}
-
-static void update_target(struct pm_qos_object *o, struct plist_node *node,
- int del, int value)
-{
- unsigned long flags;
- int prev_value, curr_value;
-
- spin_lock_irqsave(&pm_qos_lock, flags);
- prev_value = pm_qos_get_value(o);
- /* PM_QOS_DEFAULT_VALUE is a signal that the value is unchanged */
- if (value != PM_QOS_DEFAULT_VALUE) {
- /*
- * to change the list, we atomically remove, reinit
- * with new value and add, then see if the extremal
- * changed
- */
- plist_del(node, &o->requests);
- plist_node_init(node, value);
- plist_add(node, &o->requests);
- } else if (del) {
- plist_del(node, &o->requests);
- } else {
- plist_add(node, &o->requests);
- }
- curr_value = pm_qos_get_value(o);
- pm_qos_set_value(o, curr_value);
- spin_unlock_irqrestore(&pm_qos_lock, flags);
-
- if (prev_value != curr_value)
- blocking_notifier_call_chain(o->notifiers,
- (unsigned long)curr_value,
- NULL);
-}
-
-static int register_pm_qos_misc(struct pm_qos_object *qos)
-{
- qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
- qos->pm_qos_power_miscdev.name = qos->name;
- qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
-
- return misc_register(&qos->pm_qos_power_miscdev);
-}
-
-static int find_pm_qos_object_by_minor(int minor)
-{
- int pm_qos_class;
-
- for (pm_qos_class = 0;
- pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) {
- if (minor ==
- pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor)
- return pm_qos_class;
- }
- return -1;
-}
-
-/**
- * pm_qos_request - returns current system wide qos expectation
- * @pm_qos_class: identification of which qos value is requested
- *
- * This function returns the current target value.
- */
-int pm_qos_request(int pm_qos_class)
-{
- return pm_qos_read_value(pm_qos_array[pm_qos_class]);
-}
-EXPORT_SYMBOL_GPL(pm_qos_request);
-
-int pm_qos_request_active(struct pm_qos_request_list *req)
-{
- return req->pm_qos_class != 0;
-}
-EXPORT_SYMBOL_GPL(pm_qos_request_active);
-
-/**
- * pm_qos_add_request - inserts new qos request into the list
- * @dep: pointer to a preallocated handle
- * @pm_qos_class: identifies which list of qos request to use
- * @value: defines the qos request
- *
- * This function inserts a new entry in the pm_qos_class list of requested qos
- * performance characteristics. It recomputes the aggregate QoS expectations
- * for the pm_qos_class of parameters and initializes the pm_qos_request_list
- * handle. Caller needs to save this handle for later use in updates and
- * removal.
- */
-
-void pm_qos_add_request(struct pm_qos_request_list *dep,
- int pm_qos_class, s32 value)
-{
- struct pm_qos_object *o = pm_qos_array[pm_qos_class];
- int new_value;
-
- if (pm_qos_request_active(dep)) {
- WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n");
- return;
- }
- if (value == PM_QOS_DEFAULT_VALUE)
- new_value = o->default_value;
- else
- new_value = value;
- plist_node_init(&dep->list, new_value);
- dep->pm_qos_class = pm_qos_class;
- update_target(o, &dep->list, 0, PM_QOS_DEFAULT_VALUE);
-}
-EXPORT_SYMBOL_GPL(pm_qos_add_request);
-
-/**
- * pm_qos_update_request - modifies an existing qos request
- * @pm_qos_req : handle to list element holding a pm_qos request to use
- * @value: defines the qos request
- *
- * Updates an existing qos request for the pm_qos_class of parameters along
- * with updating the target pm_qos_class value.
- *
- * Attempts are made to make this code callable on hot code paths.
- */
-void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req,
- s32 new_value)
-{
- s32 temp;
- struct pm_qos_object *o;
-
- if (!pm_qos_req) /*guard against callers passing in null */
- return;
-
- if (!pm_qos_request_active(pm_qos_req)) {
- WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n");
- return;
- }
-
- o = pm_qos_array[pm_qos_req->pm_qos_class];
-
- if (new_value == PM_QOS_DEFAULT_VALUE)
- temp = o->default_value;
- else
- temp = new_value;
-
- if (temp != pm_qos_req->list.prio)
- update_target(o, &pm_qos_req->list, 0, temp);
-}
-EXPORT_SYMBOL_GPL(pm_qos_update_request);
-
-/**
- * pm_qos_remove_request - modifies an existing qos request
- * @pm_qos_req: handle to request list element
- *
- * Will remove pm qos request from the list of requests and
- * recompute the current target value for the pm_qos_class. Call this
- * on slow code paths.
- */
-void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req)
-{
- struct pm_qos_object *o;
-
- if (pm_qos_req == NULL)
- return;
- /* silent return to keep pcm code cleaner */
-
- if (!pm_qos_request_active(pm_qos_req)) {
- WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n");
- return;
- }
-
- o = pm_qos_array[pm_qos_req->pm_qos_class];
- update_target(o, &pm_qos_req->list, 1, PM_QOS_DEFAULT_VALUE);
- memset(pm_qos_req, 0, sizeof(*pm_qos_req));
-}
-EXPORT_SYMBOL_GPL(pm_qos_remove_request);
-
-/**
- * pm_qos_add_notifier - sets notification entry for changes to target value
- * @pm_qos_class: identifies which qos target changes should be notified.
- * @notifier: notifier block managed by caller.
- *
- * will register the notifier into a notification chain that gets called
- * upon changes to the pm_qos_class target value.
- */
-int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
-{
- int retval;
-
- retval = blocking_notifier_chain_register(
- pm_qos_array[pm_qos_class]->notifiers, notifier);
-
- return retval;
-}
-EXPORT_SYMBOL_GPL(pm_qos_add_notifier);
-
-/**
- * pm_qos_remove_notifier - deletes notification entry from chain.
- * @pm_qos_class: identifies which qos target changes are notified.
- * @notifier: notifier block to be removed.
- *
- * will remove the notifier from the notification chain that gets called
- * upon changes to the pm_qos_class target value.
- */
-int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
-{
- int retval;
-
- retval = blocking_notifier_chain_unregister(
- pm_qos_array[pm_qos_class]->notifiers, notifier);
-
- return retval;
-}
-EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
-
-static int pm_qos_power_open(struct inode *inode, struct file *filp)
-{
- long pm_qos_class;
-
- pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
- if (pm_qos_class >= 0) {
- struct pm_qos_request_list *req = kzalloc(sizeof(*req), GFP_KERNEL);
- if (!req)
- return -ENOMEM;
-
- pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
- filp->private_data = req;
-
- if (filp->private_data)
- return 0;
- }
- return -EPERM;
-}
-
-static int pm_qos_power_release(struct inode *inode, struct file *filp)
-{
- struct pm_qos_request_list *req;
-
- req = filp->private_data;
- pm_qos_remove_request(req);
- kfree(req);
-
- return 0;
-}
-
-
-static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
- size_t count, loff_t *f_pos)
-{
- s32 value;
- unsigned long flags;
- struct pm_qos_object *o;
- struct pm_qos_request_list *pm_qos_req = filp->private_data;
-
- if (!pm_qos_req)
- return -EINVAL;
- if (!pm_qos_request_active(pm_qos_req))
- return -EINVAL;
-
- o = pm_qos_array[pm_qos_req->pm_qos_class];
- spin_lock_irqsave(&pm_qos_lock, flags);
- value = pm_qos_get_value(o);
- spin_unlock_irqrestore(&pm_qos_lock, flags);
-
- return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32));
-}
-
-static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
- size_t count, loff_t *f_pos)
-{
- s32 value;
- struct pm_qos_request_list *pm_qos_req;
-
- if (count == sizeof(s32)) {
- if (copy_from_user(&value, buf, sizeof(s32)))
- return -EFAULT;
- } else if (count <= 11) { /* ASCII perhaps? */
- char ascii_value[11];
- unsigned long int ulval;
- int ret;
-
- if (copy_from_user(ascii_value, buf, count))
- return -EFAULT;
-
- if (count > 10) {
- if (ascii_value[10] == '\n')
- ascii_value[10] = '\0';
- else
- return -EINVAL;
- } else {
- ascii_value[count] = '\0';
- }
- ret = strict_strtoul(ascii_value, 16, &ulval);
- if (ret) {
- pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret);
- return -EINVAL;
- }
- value = (s32)lower_32_bits(ulval);
- } else {
- return -EINVAL;
- }
-
- pm_qos_req = filp->private_data;
- pm_qos_update_request(pm_qos_req, value);
-
- return count;
-}
-
-
-static int __init pm_qos_power_init(void)
-{
- int ret = 0;
-
- ret = register_pm_qos_misc(&cpu_dma_pm_qos);
- if (ret < 0) {
- printk(KERN_ERR "pm_qos_param: cpu_dma_latency setup failed\n");
- return ret;
- }
- ret = register_pm_qos_misc(&network_lat_pm_qos);
- if (ret < 0) {
- printk(KERN_ERR "pm_qos_param: network_latency setup failed\n");
- return ret;
- }
- ret = register_pm_qos_misc(&network_throughput_pm_qos);
- if (ret < 0)
- printk(KERN_ERR
- "pm_qos_param: network_throughput setup failed\n");
-
- return ret;
-}
-
-late_initcall(pm_qos_power_init);