arch/blackfin/include/asm/system.h

   1 /*
   2  * U-boot - system.h
   3  *
   4  * Copyright (c) 2005-2007 Analog Devices Inc.
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program 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
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  22  * MA 02110-1301 USA
  23  */
  24
  25 #ifndef _BLACKFIN_SYSTEM_H
  26 #define _BLACKFIN_SYSTEM_H
  27
  28 /*
  29  * Interrupt configuring macros.
  30  */
  31
  32 extern int irq_flags;
  33
  34 #define local_irq_enable() \
  35         __asm__ __volatile__ ( \
  36                 "sti %0;" \
  37                 : \
  38                 : "d" (irq_flags) \
  39         )
  40
  41 #define local_irq_disable() \
  42         do { \
  43                 int __tmp_dummy; \
  44                 __asm__ __volatile__ ( \
  45                         "cli %0;" \
  46                         : "=d" (__tmp_dummy) \
  47                 ); \
  48         } while (0)
  49
  50 # define local_irq_save(x) \
  51         __asm__ __volatile__ ( \
  52                 "cli %0;" \
  53                 : "=&d" (x) \
  54         )
  55
  56 #define local_save_flags(x) \
  57         __asm__ __volatile__ ( \
  58                 "cli %0;" \
  59                 "sti %0;" \
  60                 : "=d" (x) \
  61         )
  62
  63 #define irqs_enabled_from_flags(x) ((x) != 0x1f)
  64
  65 #define local_irq_restore(x) \
  66         do { \
  67                 if (irqs_enabled_from_flags(x)) \
  68                         local_irq_enable(); \
  69         } while (0)
  70
  71 /*
  72  * Force strict CPU ordering.
  73  */
  74 #define nop()                   asm volatile ("nop;\n\t"::)
  75 #define mb()                    asm volatile (""   : : :"memory")
  76 #define rmb()                   asm volatile (""   : : :"memory")
  77 #define wmb()                   asm volatile (""   : : :"memory")
  78 #define set_rmb(var, value)     do { xchg(&var, value); } while (0)
  79 #define set_mb(var, value)      set_rmb(var, value)
  80 #define set_wmb(var, value)     do { var = value; wmb(); } while (0)
  81
  82 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
  83
  84 struct __xchg_dummy {
  85         unsigned long a[100];
  86 };
  87 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
  88
  89 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
  90                                    int size)
  91 {
  92         unsigned long tmp = 0;
  93         unsigned long flags = 0;
  94
  95         local_irq_save(flags);
  96
  97         switch (size) {
  98         case 1:
  99                 __asm__ __volatile__
 100                         ("%0 = b%2 (z);\n\t"
 101                          "b%2 = %1;\n\t"
 102                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 103                 break;
 104         case 2:
 105                 __asm__ __volatile__
 106                         ("%0 = w%2 (z);\n\t"
 107                          "w%2 = %1;\n\t"
 108                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 109                 break;
 110         case 4:
 111                 __asm__ __volatile__
 112                         ("%0 = %2;\n\t"
 113                          "%2 = %1;\n\t"
 114                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 115                 break;
 116         }
 117         local_irq_restore(flags);
 118         return tmp;
 119 }
 120
 121 #endif  /* _BLACKFIN_SYSTEM_H */