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 library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  22  */
  23
  24 #ifdef USE_IMMEDIATE
  25
  26 #include <asm/immediate.h>
  27
  28 /**
  29  * imv_set - set immediate variable (with locking)
  30  * @name: immediate value name
  31  * @i: required value
  32  *
  33  * Sets the value of @name, taking the module_mutex if required by
  34  * the architecture.
  35  */
  36 #define imv_set(name, i)                                                \
  37         do {                                                            \
  38                 name##__imv = (i);                                      \
  39                 core_imv_update();                                      \
  40                 module_imv_update();                                    \
  41         } while (0)
  42
  43 /*
  44  * Internal update functions.
  45  */
  46 extern void core_imv_update(void);
  47 extern void imv_update_range(const struct __imv *begin,
  48         const struct __imv *end);
  49 extern void imv_unref_core_init(void);
  50 extern void imv_unref(struct __imv *begin, struct __imv *end, void *start,
  51                 unsigned long size);
  52
  53 #else
  54
  55 /*
  56  * Generic immediate values: a simple, standard, memory load.
  57  */
  58
  59 /**
  60  * imv_read - read immediate variable
  61  * @name: immediate value name
  62  *
  63  * Reads the value of @name.
  64  */
  65 #define imv_read(name)                  _imv_read(name)
  66
  67 /**
  68  * imv_set - set immediate variable (with locking)
  69  * @name: immediate value name
  70  * @i: required value
  71  *
  72  * Sets the value of @name, taking the module_mutex if required by
  73  * the architecture.
  74  */
  75 #define imv_set(name, i)                (name##__imv = (i))
  76
  77 static inline void core_imv_update(void) { }
  78 static inline void imv_unref_core_init(void) { }
  79
  80 #endif
  81
  82 #define DECLARE_IMV(type, name) extern __typeof__(type) name##__imv
  83 #define DEFINE_IMV(type, name)  __typeof__(type) name##__imv
  84
  85 #define EXPORT_IMV_SYMBOL(name) EXPORT_SYMBOL(name##__imv)
  86 #define EXPORT_IMV_SYMBOL_GPL(name) EXPORT_SYMBOL_GPL(name##__imv)
  87
  88 /**
  89  * _imv_read - Read immediate value with standard memory load.
  90  * @name: immediate value name
  91  *
  92  * Force a data read of the immediate value instead of the immediate value
  93  * based mechanism. Useful for __init and __exit section data read.
  94  */
  95 #define _imv_read(name)         (name##__imv)
  96
  97 #endif