reactos/ntoskrnl/include/internal/i386/asmmacro.S

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnlinclude/i386/asmmacro.S
   5  * PURPOSE:         Assembly Macros for Spinlocks and common Trap Code (TODO)
   6  * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
   7  */
   8
   9 /* INCLUDES ******************************************************************/
  10 #include <ndk/asm.h>
  11 .intel_syntax noprefix
  12
  13 //
  14 // These macros are inlined equivalents of KiAcquire/ReleaseSpinlock, that is,
  15 // they will not be compiled into non-SMP builds. Usage is as follows:
  16 //
  17 // .BeginYourFunction
  18 //      mov reg, lockaddr
  19 //      ACQUIRE_SPINLOCK(reg, .spin)
  20 //      <thread-safe code here>
  21 //      RELEASE_SPINLOCK(reg)
  22 //      <misc code here>
  23 //  retn
  24 //  #IFDEF CONFIG_SMP
  25 //  .spin
  26 //      <any necessary steps to be able to jump back safely>
  27 /       SPIN_ON_LOCK(reg, .BeginYourFunction)
  28 //  #ENDIF
  29 //
  30 #ifdef CONFIG_SMP
  31 #define LOCK lock
  32 #define ACQUIRE_SPINLOCK(x, y) \
  33     lock bts dword ptr [x], 0; \
  34     jb y
  35 #define RELEASE_SPINLOCK(x) mov byte ptr [x], 0
  36 #define SPIN_ON_LOCK(x, y) \
  37 1: \
  38     test dword ptr [x], 1; \
  39     jz y; \
  40     pause; \
  41     jmp 1b
  42 #else
  43 #define LOCK
  44 #define ACQUIRE_SPINLOCK(x, y)
  45 #define RELEASE_SPINLOCK(x)
  46 #endif
  47
  48 //
  49 // These macros control common execution paths for Traps and System Call Code
  50 // TODO
  51 //
  52