/*
|
* 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.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/debugfs.h>
|
#include <linux/seq_file.h>
|
#include <linux/irq.h>
|
#include <linux/irqdesc.h>
|
|
#include <linux/uaccess.h>
|
#include <linux/export.h>
|
#include <trace/events/power.h>
|
|
/*
|
* locking rule: all changes to constraints 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
|
*/
|
struct pm_qos_object {
|
struct pm_qos_constraints *constraints;
|
struct miscdevice pm_qos_power_miscdev;
|
char *name;
|
};
|
|
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_constraints cpu_dma_constraints = {
|
.list = PLIST_HEAD_INIT(cpu_dma_constraints.list),
|
.target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
|
.target_per_cpu = { [0 ... (NR_CPUS - 1)] =
|
PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE },
|
.default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
|
.no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
|
.type = PM_QOS_MIN,
|
.notifiers = &cpu_dma_lat_notifier,
|
};
|
static struct pm_qos_object cpu_dma_pm_qos = {
|
.constraints = &cpu_dma_constraints,
|
.name = "cpu_dma_latency",
|
};
|
|
static BLOCKING_NOTIFIER_HEAD(network_lat_notifier);
|
static struct pm_qos_constraints network_lat_constraints = {
|
.list = PLIST_HEAD_INIT(network_lat_constraints.list),
|
.target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
|
.target_per_cpu = { [0 ... (NR_CPUS - 1)] =
|
PM_QOS_NETWORK_LAT_DEFAULT_VALUE },
|
.default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
|
.no_constraint_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
|
.type = PM_QOS_MIN,
|
.notifiers = &network_lat_notifier,
|
};
|
static struct pm_qos_object network_lat_pm_qos = {
|
.constraints = &network_lat_constraints,
|
.name = "network_latency",
|
};
|
|
static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier);
|
static struct pm_qos_constraints network_tput_constraints = {
|
.list = PLIST_HEAD_INIT(network_tput_constraints.list),
|
.target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
|
.target_per_cpu = { [0 ... (NR_CPUS - 1)] =
|
PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE },
|
.default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
|
.no_constraint_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
|
.type = PM_QOS_MAX,
|
.notifiers = &network_throughput_notifier,
|
};
|
static struct pm_qos_object network_throughput_pm_qos = {
|
.constraints = &network_tput_constraints,
|
.name = "network_throughput",
|
};
|
|
|
static BLOCKING_NOTIFIER_HEAD(memory_bandwidth_notifier);
|
static struct pm_qos_constraints memory_bw_constraints = {
|
.list = PLIST_HEAD_INIT(memory_bw_constraints.list),
|
.target_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE,
|
.default_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE,
|
.no_constraint_value = PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE,
|
.type = PM_QOS_SUM,
|
.notifiers = &memory_bandwidth_notifier,
|
};
|
static struct pm_qos_object memory_bandwidth_pm_qos = {
|
.constraints = &memory_bw_constraints,
|
.name = "memory_bandwidth",
|
};
|
|
|
static struct pm_qos_object *pm_qos_array[] = {
|
&null_pm_qos,
|
&cpu_dma_pm_qos,
|
&network_lat_pm_qos,
|
&network_throughput_pm_qos,
|
&memory_bandwidth_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_constraints *c)
|
{
|
struct plist_node *node;
|
int total_value = 0;
|
|
if (plist_head_empty(&c->list))
|
return c->no_constraint_value;
|
|
switch (c->type) {
|
case PM_QOS_MIN:
|
return plist_first(&c->list)->prio;
|
|
case PM_QOS_MAX:
|
return plist_last(&c->list)->prio;
|
|
case PM_QOS_SUM:
|
plist_for_each(node, &c->list)
|
total_value += node->prio;
|
|
return total_value;
|
|
default:
|
/* runtime check for not using enum */
|
BUG();
|
return PM_QOS_DEFAULT_VALUE;
|
}
|
}
|
|
s32 pm_qos_read_value(struct pm_qos_constraints *c)
|
{
|
return c->target_value;
|
}
|
|
static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
|
{
|
c->target_value = value;
|
}
|
|
static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused)
|
{
|
struct pm_qos_object *qos = (struct pm_qos_object *)s->private;
|
struct pm_qos_constraints *c;
|
struct pm_qos_request *req;
|
char *type;
|
unsigned long flags;
|
int tot_reqs = 0;
|
int active_reqs = 0;
|
|
if (IS_ERR_OR_NULL(qos)) {
|
pr_err("%s: bad qos param!\n", __func__);
|
return -EINVAL;
|
}
|
c = qos->constraints;
|
if (IS_ERR_OR_NULL(c)) {
|
pr_err("%s: Bad constraints on qos?\n", __func__);
|
return -EINVAL;
|
}
|
|
/* Lock to ensure we have a snapshot */
|
spin_lock_irqsave(&pm_qos_lock, flags);
|
if (plist_head_empty(&c->list)) {
|
seq_puts(s, "Empty!\n");
|
goto out;
|
}
|
|
switch (c->type) {
|
case PM_QOS_MIN:
|
type = "Minimum";
|
break;
|
case PM_QOS_MAX:
|
type = "Maximum";
|
break;
|
case PM_QOS_SUM:
|
type = "Sum";
|
break;
|
default:
|
type = "Unknown";
|
}
|
|
plist_for_each_entry(req, &c->list, node) {
|
char *state = "Default";
|
|
if ((req->node).prio != c->default_value) {
|
active_reqs++;
|
state = "Active";
|
}
|
tot_reqs++;
|
seq_printf(s, "%d: %d: %s\n", tot_reqs,
|
(req->node).prio, state);
|
}
|
|
seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n",
|
type, pm_qos_get_value(c), active_reqs, tot_reqs);
|
|
out:
|
spin_unlock_irqrestore(&pm_qos_lock, flags);
|
return 0;
|
}
|
|
static int pm_qos_dbg_open(struct inode *inode, struct file *file)
|
{
|
return single_open(file, pm_qos_dbg_show_requests,
|
inode->i_private);
|
}
|
|
static const struct file_operations pm_qos_debug_fops = {
|
.open = pm_qos_dbg_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = single_release,
|
};
|
|
static inline void pm_qos_set_value_for_cpus(struct pm_qos_constraints *c,
|
bool dev_req)
|
{
|
struct pm_qos_request *req = NULL;
|
int cpu;
|
s32 qos_val[NR_CPUS] = { [0 ... (NR_CPUS - 1)] = c->default_value };
|
|
/*
|
* pm_qos_set_value_for_cpus expects all c->list elements to be of type
|
* pm_qos_request, however requests from device will contain elements
|
* of type dev_pm_qos_request.
|
* pm_qos_constraints.target_per_cpu can be accessed only for
|
* constraints associated with one of the pm_qos_class and present in
|
* pm_qos_array. Device requests are not associated with any of
|
* pm_qos_class, therefore their target_per_cpu cannot be accessed. We
|
* can safely skip updating target_per_cpu for device requests.
|
*/
|
if (dev_req)
|
return;
|
|
plist_for_each_entry(req, &c->list, node) {
|
for_each_cpu(cpu, &req->cpus_affine) {
|
switch (c->type) {
|
case PM_QOS_MIN:
|
if (qos_val[cpu] > req->node.prio)
|
qos_val[cpu] = req->node.prio;
|
break;
|
case PM_QOS_MAX:
|
if (req->node.prio > qos_val[cpu])
|
qos_val[cpu] = req->node.prio;
|
break;
|
default:
|
break;
|
}
|
}
|
}
|
|
for_each_possible_cpu(cpu)
|
c->target_per_cpu[cpu] = qos_val[cpu];
|
}
|
|
/**
|
* pm_qos_update_target - manages the constraints list and calls the notifiers
|
* if needed
|
* @c: constraints data struct
|
* @node: request to add to the list, to update or to remove
|
* @action: action to take on the constraints list
|
* @value: value of the request to add or update
|
*
|
* This function returns 1 if the aggregated constraint value has changed, 0
|
* otherwise.
|
*/
|
int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
|
enum pm_qos_req_action action, int value, bool dev_req)
|
{
|
unsigned long flags;
|
int prev_value, curr_value, new_value;
|
int ret;
|
|
spin_lock_irqsave(&pm_qos_lock, flags);
|
prev_value = pm_qos_get_value(c);
|
if (value == PM_QOS_DEFAULT_VALUE)
|
new_value = c->default_value;
|
else
|
new_value = value;
|
|
switch (action) {
|
case PM_QOS_REMOVE_REQ:
|
plist_del(node, &c->list);
|
break;
|
case PM_QOS_UPDATE_REQ:
|
/*
|
* to change the list, we atomically remove, reinit
|
* with new value and add, then see if the extremal
|
* changed
|
*/
|
plist_del(node, &c->list);
|
/* fall through */
|
case PM_QOS_ADD_REQ:
|
plist_node_init(node, new_value);
|
plist_add(node, &c->list);
|
break;
|
default:
|
/* no action */
|
;
|
}
|
|
curr_value = pm_qos_get_value(c);
|
pm_qos_set_value(c, curr_value);
|
pm_qos_set_value_for_cpus(c, dev_req);
|
|
spin_unlock_irqrestore(&pm_qos_lock, flags);
|
|
trace_pm_qos_update_target(action, prev_value, curr_value);
|
if (prev_value != curr_value) {
|
ret = 1;
|
if (c->notifiers)
|
blocking_notifier_call_chain(c->notifiers,
|
(unsigned long)curr_value,
|
NULL);
|
} else {
|
ret = 0;
|
}
|
return ret;
|
}
|
|
/**
|
* pm_qos_flags_remove_req - Remove device PM QoS flags request.
|
* @pqf: Device PM QoS flags set to remove the request from.
|
* @req: Request to remove from the set.
|
*/
|
static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
|
struct pm_qos_flags_request *req)
|
{
|
s32 val = 0;
|
|
list_del(&req->node);
|
list_for_each_entry(req, &pqf->list, node)
|
val |= req->flags;
|
|
pqf->effective_flags = val;
|
}
|
|
/**
|
* pm_qos_update_flags - Update a set of PM QoS flags.
|
* @pqf: Set of flags to update.
|
* @req: Request to add to the set, to modify, or to remove from the set.
|
* @action: Action to take on the set.
|
* @val: Value of the request to add or modify.
|
*
|
* Update the given set of PM QoS flags and call notifiers if the aggregate
|
* value has changed. Returns 1 if the aggregate constraint value has changed,
|
* 0 otherwise.
|
*/
|
bool pm_qos_update_flags(struct pm_qos_flags *pqf,
|
struct pm_qos_flags_request *req,
|
enum pm_qos_req_action action, s32 val)
|
{
|
unsigned long irqflags;
|
s32 prev_value, curr_value;
|
|
spin_lock_irqsave(&pm_qos_lock, irqflags);
|
|
prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
|
|
switch (action) {
|
case PM_QOS_REMOVE_REQ:
|
pm_qos_flags_remove_req(pqf, req);
|
break;
|
case PM_QOS_UPDATE_REQ:
|
pm_qos_flags_remove_req(pqf, req);
|
/* fall through */
|
case PM_QOS_ADD_REQ:
|
req->flags = val;
|
INIT_LIST_HEAD(&req->node);
|
list_add_tail(&req->node, &pqf->list);
|
pqf->effective_flags |= val;
|
break;
|
default:
|
/* no action */
|
;
|
}
|
|
curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
|
|
spin_unlock_irqrestore(&pm_qos_lock, irqflags);
|
|
trace_pm_qos_update_flags(action, prev_value, curr_value);
|
return prev_value != curr_value;
|
}
|
|
/**
|
* 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]->constraints);
|
}
|
EXPORT_SYMBOL_GPL(pm_qos_request);
|
|
int pm_qos_request_for_cpu(int pm_qos_class, int cpu)
|
{
|
return pm_qos_array[pm_qos_class]->constraints->target_per_cpu[cpu];
|
}
|
EXPORT_SYMBOL(pm_qos_request_for_cpu);
|
|
int pm_qos_request_active(struct pm_qos_request *req)
|
{
|
return req->pm_qos_class != 0;
|
}
|
EXPORT_SYMBOL_GPL(pm_qos_request_active);
|
|
int pm_qos_request_for_cpumask(int pm_qos_class, struct cpumask *mask)
|
{
|
unsigned long irqflags;
|
int cpu;
|
struct pm_qos_constraints *c = NULL;
|
int val;
|
|
spin_lock_irqsave(&pm_qos_lock, irqflags);
|
c = pm_qos_array[pm_qos_class]->constraints;
|
val = c->default_value;
|
|
for_each_cpu(cpu, mask) {
|
switch (c->type) {
|
case PM_QOS_MIN:
|
if (c->target_per_cpu[cpu] < val)
|
val = c->target_per_cpu[cpu];
|
break;
|
case PM_QOS_MAX:
|
if (c->target_per_cpu[cpu] > val)
|
val = c->target_per_cpu[cpu];
|
break;
|
default:
|
break;
|
}
|
}
|
spin_unlock_irqrestore(&pm_qos_lock, irqflags);
|
|
return val;
|
}
|
EXPORT_SYMBOL(pm_qos_request_for_cpumask);
|
|
static void __pm_qos_update_request(struct pm_qos_request *req,
|
s32 new_value)
|
{
|
trace_pm_qos_update_request(req->pm_qos_class, new_value);
|
|
if (new_value != req->node.prio)
|
pm_qos_update_target(
|
pm_qos_array[req->pm_qos_class]->constraints,
|
&req->node, PM_QOS_UPDATE_REQ, new_value, false);
|
}
|
|
/**
|
* pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
|
* @work: work struct for the delayed work (timeout)
|
*
|
* This cancels the timeout request by falling back to the default at timeout.
|
*/
|
static void pm_qos_work_fn(struct work_struct *work)
|
{
|
struct pm_qos_request *req = container_of(to_delayed_work(work),
|
struct pm_qos_request,
|
work);
|
|
__pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
|
}
|
|
#ifdef CONFIG_SMP
|
static void pm_qos_irq_release(struct kref *ref)
|
{
|
unsigned long flags;
|
struct irq_affinity_notify *notify = container_of(ref,
|
struct irq_affinity_notify, kref);
|
struct pm_qos_request *req = container_of(notify,
|
struct pm_qos_request, irq_notify);
|
struct pm_qos_constraints *c =
|
pm_qos_array[req->pm_qos_class]->constraints;
|
|
spin_lock_irqsave(&pm_qos_lock, flags);
|
cpumask_setall(&req->cpus_affine);
|
spin_unlock_irqrestore(&pm_qos_lock, flags);
|
|
pm_qos_update_target(c, &req->node, PM_QOS_UPDATE_REQ,
|
c->default_value, false);
|
}
|
|
static void pm_qos_irq_notify(struct irq_affinity_notify *notify,
|
const cpumask_t *mask)
|
{
|
unsigned long flags;
|
struct pm_qos_request *req = container_of(notify,
|
struct pm_qos_request, irq_notify);
|
struct pm_qos_constraints *c =
|
pm_qos_array[req->pm_qos_class]->constraints;
|
|
spin_lock_irqsave(&pm_qos_lock, flags);
|
cpumask_copy(&req->cpus_affine, mask);
|
spin_unlock_irqrestore(&pm_qos_lock, flags);
|
|
pm_qos_update_target(c, &req->node, PM_QOS_UPDATE_REQ, req->node.prio,
|
false);
|
}
|
#endif
|
|
/**
|
* pm_qos_add_request - inserts new qos request into the list
|
* @req: 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
|
* handle. Caller needs to save this handle for later use in updates and
|
* removal.
|
*/
|
|
void pm_qos_add_request(struct pm_qos_request *req,
|
int pm_qos_class, s32 value)
|
{
|
if (!req) /*guard against callers passing in null */
|
return;
|
|
if (pm_qos_request_active(req)) {
|
WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n");
|
return;
|
}
|
|
switch (req->type) {
|
case PM_QOS_REQ_AFFINE_CORES:
|
if (cpumask_empty(&req->cpus_affine)) {
|
req->type = PM_QOS_REQ_ALL_CORES;
|
cpumask_setall(&req->cpus_affine);
|
WARN(1, "Affine cores not set for request with affinity flag\n");
|
}
|
break;
|
#ifdef CONFIG_SMP
|
case PM_QOS_REQ_AFFINE_IRQ:
|
if (irq_can_set_affinity(req->irq)) {
|
struct irq_desc *desc = irq_to_desc(req->irq);
|
struct cpumask *mask;
|
|
if (!desc)
|
return;
|
|
mask = desc->irq_data.common->affinity;
|
|
/* Get the current affinity */
|
cpumask_copy(&req->cpus_affine, mask);
|
req->irq_notify.irq = req->irq;
|
req->irq_notify.notify = pm_qos_irq_notify;
|
req->irq_notify.release = pm_qos_irq_release;
|
|
} else {
|
req->type = PM_QOS_REQ_ALL_CORES;
|
cpumask_setall(&req->cpus_affine);
|
WARN(1, "IRQ-%d not set for request with affinity flag\n",
|
req->irq);
|
}
|
break;
|
#endif
|
default:
|
WARN(1, "Unknown request type %d\n", req->type);
|
/* fall through */
|
case PM_QOS_REQ_ALL_CORES:
|
cpumask_setall(&req->cpus_affine);
|
break;
|
}
|
|
req->pm_qos_class = pm_qos_class;
|
INIT_DELAYED_WORK(&req->work, pm_qos_work_fn);
|
trace_pm_qos_add_request(pm_qos_class, value);
|
pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints,
|
&req->node, PM_QOS_ADD_REQ, value, false);
|
|
#ifdef CONFIG_SMP
|
if (req->type == PM_QOS_REQ_AFFINE_IRQ &&
|
irq_can_set_affinity(req->irq)) {
|
int ret = 0;
|
|
ret = irq_set_affinity_notifier(req->irq,
|
&req->irq_notify);
|
if (ret) {
|
WARN(1, "IRQ affinity notify set failed\n");
|
req->type = PM_QOS_REQ_ALL_CORES;
|
cpumask_setall(&req->cpus_affine);
|
pm_qos_update_target(
|
pm_qos_array[pm_qos_class]->constraints,
|
&req->node, PM_QOS_UPDATE_REQ, value, false);
|
}
|
}
|
#endif
|
}
|
EXPORT_SYMBOL_GPL(pm_qos_add_request);
|
|
/**
|
* pm_qos_update_request - modifies an existing qos request
|
* @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 *req,
|
s32 new_value)
|
{
|
if (!req) /*guard against callers passing in null */
|
return;
|
|
if (!pm_qos_request_active(req)) {
|
WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n");
|
return;
|
}
|
|
cancel_delayed_work_sync(&req->work);
|
__pm_qos_update_request(req, new_value);
|
}
|
EXPORT_SYMBOL_GPL(pm_qos_update_request);
|
|
/**
|
* pm_qos_update_request_timeout - modifies an existing qos request temporarily.
|
* @req : handle to list element holding a pm_qos request to use
|
* @new_value: defines the temporal qos request
|
* @timeout_us: the effective duration of this qos request in usecs.
|
*
|
* After timeout_us, this qos request is cancelled automatically.
|
*/
|
void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
|
unsigned long timeout_us)
|
{
|
if (!req)
|
return;
|
if (WARN(!pm_qos_request_active(req),
|
"%s called for unknown object.", __func__))
|
return;
|
|
cancel_delayed_work_sync(&req->work);
|
|
trace_pm_qos_update_request_timeout(req->pm_qos_class,
|
new_value, timeout_us);
|
if (new_value != req->node.prio)
|
pm_qos_update_target(
|
pm_qos_array[req->pm_qos_class]->constraints,
|
&req->node, PM_QOS_UPDATE_REQ, new_value, false);
|
|
schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us));
|
}
|
EXPORT_SYMBOL_GPL(pm_qos_update_request_timeout);
|
|
/**
|
* 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 for the pm_qos_class. Call this
|
* on slow code paths.
|
*/
|
void pm_qos_remove_request(struct pm_qos_request *req)
|
{
|
if (!req) /*guard against callers passing in null */
|
return;
|
/* silent return to keep pcm code cleaner */
|
|
if (!pm_qos_request_active(req)) {
|
WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n");
|
return;
|
}
|
|
cancel_delayed_work_sync(&req->work);
|
|
trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE);
|
pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
|
&req->node, PM_QOS_REMOVE_REQ,
|
PM_QOS_DEFAULT_VALUE, false);
|
memset(req, 0, sizeof(*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]->constraints->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]->constraints->notifiers,
|
notifier);
|
|
return retval;
|
}
|
EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
|
|
/* User space interface to PM QoS classes via misc devices */
|
static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d)
|
{
|
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;
|
|
if (d) {
|
(void)debugfs_create_file(qos->name, S_IRUGO, d,
|
(void *)qos, &pm_qos_debug_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 = PM_QOS_CPU_DMA_LATENCY;
|
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;
|
}
|
|
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 >= PM_QOS_CPU_DMA_LATENCY) {
|
struct pm_qos_request *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;
|
|
return 0;
|
}
|
return -EPERM;
|
}
|
|
static int pm_qos_power_release(struct inode *inode, struct file *filp)
|
{
|
struct pm_qos_request *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_request *req = filp->private_data;
|
|
if (!req)
|
return -EINVAL;
|
if (!pm_qos_request_active(req))
|
return -EINVAL;
|
|
spin_lock_irqsave(&pm_qos_lock, flags);
|
value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints);
|
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 *req;
|
|
if (count == sizeof(s32)) {
|
if (copy_from_user(&value, buf, sizeof(s32)))
|
return -EFAULT;
|
} else {
|
int ret;
|
|
ret = kstrtos32_from_user(buf, count, 16, &value);
|
if (ret)
|
return ret;
|
}
|
|
req = filp->private_data;
|
pm_qos_update_request(req, value);
|
|
return count;
|
}
|
|
|
static int __init pm_qos_power_init(void)
|
{
|
int ret = 0;
|
int i;
|
struct dentry *d;
|
|
BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);
|
|
d = debugfs_create_dir("pm_qos", NULL);
|
if (IS_ERR_OR_NULL(d))
|
d = NULL;
|
|
for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
|
ret = register_pm_qos_misc(pm_qos_array[i], d);
|
if (ret < 0) {
|
pr_err("%s: %s setup failed\n",
|
__func__, pm_qos_array[i]->name);
|
return ret;
|
}
|
}
|
|
return ret;
|
}
|
|
late_initcall(pm_qos_power_init);
|
