arch/c6x/include/asm/cmpxchg.h

   1 /*
   2  *  Port on Texas Instruments TMS320C6x architecture
   3  *
   4  *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
   5  *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  */
  11 #ifndef _ASM_C6X_CMPXCHG_H
  12 #define _ASM_C6X_CMPXCHG_H
  13
  14 #include <linux/irqflags.h>
  15
  16 /*
  17  * Misc. functions
  18  */
  19 static inline unsigned int __xchg(unsigned int x, volatile void *ptr, int size)
  20 {
  21         unsigned int tmp;
  22         unsigned long flags;
  23
  24         local_irq_save(flags);
  25
  26         switch (size) {
  27         case 1:
  28                 tmp = 0;
  29                 tmp = *((unsigned char *) ptr);
  30                 *((unsigned char *) ptr) = (unsigned char) x;
  31                 break;
  32         case 2:
  33                 tmp = 0;
  34                 tmp = *((unsigned short *) ptr);
  35                 *((unsigned short *) ptr) = x;
  36                 break;
  37         case 4:
  38                 tmp = 0;
  39                 tmp = *((unsigned int *) ptr);
  40                 *((unsigned int *) ptr) = x;
  41                 break;
  42         }
  43         local_irq_restore(flags);
  44         return tmp;
  45 }
  46
  47 #define xchg(ptr, x) \
  48         ((__typeof__(*(ptr)))__xchg((unsigned int)(x), (void *) (ptr), \
  49                                     sizeof(*(ptr))))
  50
  51 #include <asm-generic/cmpxchg-local.h>
  52
  53 /*
  54  * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
  55  * them available.
  56  */
  57 #define cmpxchg_local(ptr, o, n)                                        \
  58         ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr),             \
  59                                                      (unsigned long)(o), \
  60                                                      (unsigned long)(n), \
  61                                                      sizeof(*(ptr))))
  62 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
  63
  64 #include <asm-generic/cmpxchg.h>
  65
  66 #endif /* _ASM_C6X_CMPXCHG_H */