include/linux/pm_qos.h

   1 #ifndef _LINUX_PM_QOS_H
   2 #define _LINUX_PM_QOS_H
   3 /* interface for the pm_qos_power infrastructure of the linux kernel.
   4  *
   5  * Mark Gross <mgross@linux.intel.com>
   6  */
   7 #include <linux/plist.h>
   8 #include <linux/notifier.h>
   9 #include <linux/miscdevice.h>
  10
  11 #define PM_QOS_RESERVED 0
  12 #define PM_QOS_CPU_DMA_LATENCY 1
  13 #define PM_QOS_NETWORK_LATENCY 2
  14 #define PM_QOS_NETWORK_THROUGHPUT 3
  15
  16 #define PM_QOS_NUM_CLASSES 4
  17 #define PM_QOS_DEFAULT_VALUE -1
  18
  19 #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE        (2000 * USEC_PER_SEC)
  20 #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE        (2000 * USEC_PER_SEC)
  21 #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0
  22
  23 struct pm_qos_request {
  24         struct plist_node node;
  25         int pm_qos_class;
  26 };
  27
  28 enum pm_qos_type {
  29         PM_QOS_UNITIALIZED,
  30         PM_QOS_MAX,             /* return the largest value */
  31         PM_QOS_MIN              /* return the smallest value */
  32 };
  33
  34 /*
  35  * Note: The lockless read path depends on the CPU accessing
  36  * target_value atomically.  Atomic access is only guaranteed on all CPU
  37  * types linux supports for 32 bit quantites
  38  */
  39 struct pm_qos_constraints {
  40         struct plist_head list;
  41         s32 target_value;       /* Do not change to 64 bit */
  42         s32 default_value;
  43         enum pm_qos_type type;
  44         struct blocking_notifier_head *notifiers;
  45 };
  46
  47 #ifdef CONFIG_PM
  48 void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
  49                         s32 value);
  50 void pm_qos_update_request(struct pm_qos_request *req,
  51                            s32 new_value);
  52 void pm_qos_remove_request(struct pm_qos_request *req);
  53
  54 int pm_qos_request(int pm_qos_class);
  55 int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
  56 int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
  57 int pm_qos_request_active(struct pm_qos_request *req);
  58 #else
  59 static inline void pm_qos_add_request(struct pm_qos_request *req,
  60                                       int pm_qos_class, s32 value)
  61                         { return; }
  62 static inline void pm_qos_update_request(struct pm_qos_request *req,
  63                                          s32 new_value)
  64                         { return; }
  65 static inline void pm_qos_remove_request(struct pm_qos_request *req)
  66                         { return; }
  67
  68 static inline int pm_qos_request(int pm_qos_class)
  69                         { return 0; }
  70 static inline int pm_qos_add_notifier(int pm_qos_class,
  71                                       struct notifier_block *notifier)
  72                         { return 0; }
  73 static inline int pm_qos_remove_notifier(int pm_qos_class,
  74                                          struct notifier_block *notifier)
  75                         { return 0; }
  76 static inline int pm_qos_request_active(struct pm_qos_request *req)
  77                         { return 0; }
  78 #endif
  79
  80 #endif