libust/immediate.h

   1 #ifndef _LINUX_IMMEDIATE_H
   2 #define _LINUX_IMMEDIATE_H
   3
   4 /*
   5  * Immediate values, can be updated at runtime and save cache lines.
   6  *
   7  * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   8  *
   9  * This file is released under the GPLv2.
  10  * See the file COPYING for more details.
  11  */
  12
  13 #ifdef USE_IMMEDIATE
  14
  15 #include <asm/immediate.h>
  16
  17 /**
  18  * imv_set - set immediate variable (with locking)
  19  * @name: immediate value name
  20  * @i: required value
  21  *
  22  * Sets the value of @name, taking the module_mutex if required by
  23  * the architecture.
  24  */
  25 #define imv_set(name, i)                                                \
  26         do {                                                            \
  27                 name##__imv = (i);                                      \
  28                 core_imv_update();                                      \
  29                 module_imv_update();                                    \
  30         } while (0)
  31
  32 /*
  33  * Internal update functions.
  34  */
  35 extern void core_imv_update(void);
  36 extern void imv_update_range(const struct __imv *begin,
  37         const struct __imv *end);
  38 extern void imv_unref_core_init(void);
  39 extern void imv_unref(struct __imv *begin, struct __imv *end, void *start,
  40                 unsigned long size);
  41
  42 #else
  43
  44 /*
  45  * Generic immediate values: a simple, standard, memory load.
  46  */
  47
  48 /**
  49  * imv_read - read immediate variable
  50  * @name: immediate value name
  51  *
  52  * Reads the value of @name.
  53  */
  54 #define imv_read(name)                  _imv_read(name)
  55
  56 /**
  57  * imv_set - set immediate variable (with locking)
  58  * @name: immediate value name
  59  * @i: required value
  60  *
  61  * Sets the value of @name, taking the module_mutex if required by
  62  * the architecture.
  63  */
  64 #define imv_set(name, i)                (name##__imv = (i))
  65
  66 static inline void core_imv_update(void) { }
  67 static inline void imv_unref_core_init(void) { }
  68
  69 #endif
  70
  71 #define DECLARE_IMV(type, name) extern __typeof__(type) name##__imv
  72 #define DEFINE_IMV(type, name)  __typeof__(type) name##__imv
  73
  74 #define EXPORT_IMV_SYMBOL(name) EXPORT_SYMBOL(name##__imv)
  75 #define EXPORT_IMV_SYMBOL_GPL(name) EXPORT_SYMBOL_GPL(name##__imv)
  76
  77 /**
  78  * _imv_read - Read immediate value with standard memory load.
  79  * @name: immediate value name
  80  *
  81  * Force a data read of the immediate value instead of the immediate value
  82  * based mechanism. Useful for __init and __exit section data read.
  83  */
  84 #define _imv_read(name)         (name##__imv)
  85
  86 #endif