include/asm-blackfin/system.h

   1 /*
   2  * File:        include/asm/system.h
   3  * Based on:
   4  * Author:      Tony Kou (tonyko@lineo.ca)
   5  *              Copyright (c) 2002 Arcturus Networks Inc.
   6  *                    (www.arcturusnetworks.com)
   7  *              Copyright (c) 2003 Metrowerks (www.metrowerks.com)
   8  *              Copyright (c) 2004 Analog Device Inc.
   9  * Created:     25Jan2001 - Tony Kou
  10  * Description: system.h include file
  11  *
  12  * Modified:     22Sep2006 - Robin Getz
  13  *                - move include blackfin.h down, so I can get access to
  14  *                   irq functions in other include files.
  15  *
  16  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  17  *
  18  * This program is free software; you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation; either version 2, or (at your option)
  21  * any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program; see the file COPYING.
  30  * If not, write to the Free Software Foundation,
  31  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  32  */
  33
  34 #ifndef _BLACKFIN_SYSTEM_H
  35 #define _BLACKFIN_SYSTEM_H
  36
  37 #include <linux/linkage.h>
  38 #include <linux/compiler.h>
  39
  40 /*
  41  * Interrupt configuring macros.
  42  */
  43
  44 extern unsigned long irq_flags;
  45
  46 #define local_irq_enable() do {         \
  47         __asm__ __volatile__ (          \
  48                 "sti %0;"               \
  49                 ::"d"(irq_flags));      \
  50 } while (0)
  51
  52 #define local_irq_disable() do {        \
  53         int _tmp_dummy;                 \
  54         __asm__ __volatile__ (          \
  55                 "cli %0;"               \
  56                 :"=d" (_tmp_dummy):);   \
  57 } while (0)
  58
  59 #if defined(ANOMALY_05000244) && defined (CONFIG_BLKFIN_CACHE)
  60 #define idle_with_irq_disabled() do {   \
  61         __asm__ __volatile__ (          \
  62                 "nop; nop;\n"           \
  63                 ".align 8;\n"           \
  64                 "sti %0; idle;\n"       \
  65                 ::"d" (irq_flags));     \
  66 } while (0)
  67 #else
  68 #define idle_with_irq_disabled() do {   \
  69         __asm__ __volatile__ (          \
  70                 ".align 8;\n"           \
  71                 "sti %0; idle;\n"       \
  72                 ::"d" (irq_flags));     \
  73 } while (0)
  74 #endif
  75
  76 #ifdef CONFIG_DEBUG_HWERR
  77 #define __save_and_cli(x) do {                  \
  78         __asm__ __volatile__ (                  \
  79                 "cli %0;\n\tsti %1;"            \
  80                 :"=&d"(x): "d" (0x3F));         \
  81 } while (0)
  82 #else
  83 #define __save_and_cli(x) do {          \
  84         __asm__ __volatile__ (          \
  85                 "cli %0;"               \
  86                 :"=&d"(x):);            \
  87 } while (0)
  88 #endif
  89
  90 #define local_save_flags(x) asm volatile ("cli %0;"     \
  91                                           "sti %0;"     \
  92                                           :"=d"(x):);
  93
  94 #ifdef CONFIG_DEBUG_HWERR
  95 #define irqs_enabled_from_flags(x) (((x) & ~0x3f) != 0)
  96 #else
  97 #define irqs_enabled_from_flags(x) ((x) != 0x1f)
  98 #endif
  99
 100 #define local_irq_restore(x) do {                       \
 101         if (irqs_enabled_from_flags(x))                 \
 102                 local_irq_enable ();                    \
 103 } while (0)
 104
 105 /* For spinlocks etc */
 106 #define local_irq_save(x) __save_and_cli(x)
 107
 108 #define irqs_disabled()                         \
 109 ({                                              \
 110         unsigned long flags;                    \
 111         local_save_flags(flags);                \
 112         !irqs_enabled_from_flags(flags);        \
 113 })
 114
 115 /*
 116  * Force strict CPU ordering.
 117  */
 118 #define nop()  asm volatile ("nop;\n\t"::)
 119 #define mb()   asm volatile (""   : : :"memory")
 120 #define rmb()  asm volatile (""   : : :"memory")
 121 #define wmb()  asm volatile (""   : : :"memory")
 122 #define set_rmb(var, value)    do { (void) xchg(&var, value); } while (0)
 123 #define set_mb(var, value)     set_rmb(var, value)
 124 #define set_wmb(var, value)    do { var = value; wmb(); } while (0)
 125
 126 #define read_barrier_depends()          do { } while(0)
 127
 128 #ifdef CONFIG_SMP
 129 #define smp_mb()        mb()
 130 #define smp_rmb()       rmb()
 131 #define smp_wmb()       wmb()
 132 #define smp_read_barrier_depends()      read_barrier_depends()
 133 #else
 134 #define smp_mb()        barrier()
 135 #define smp_rmb()       barrier()
 136 #define smp_wmb()       barrier()
 137 #define smp_read_barrier_depends()      do { } while(0)
 138 #endif
 139
 140 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 141
 142 struct __xchg_dummy {
 143         unsigned long a[100];
 144 };
 145 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
 146
 147 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
 148                                    int size)
 149 {
 150         unsigned long tmp = 0;
 151         unsigned long flags = 0;
 152
 153         local_irq_save(flags);
 154
 155         switch (size) {
 156         case 1:
 157                 __asm__ __volatile__
 158                         ("%0 = b%2 (z);\n\t"
 159                          "b%2 = %1;\n\t"
 160                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 161                 break;
 162         case 2:
 163                 __asm__ __volatile__
 164                         ("%0 = w%2 (z);\n\t"
 165                          "w%2 = %1;\n\t"
 166                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 167                 break;
 168         case 4:
 169                 __asm__ __volatile__
 170                         ("%0 = %2;\n\t"
 171                          "%2 = %1;\n\t"
 172                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 173                 break;
 174         }
 175         local_irq_restore(flags);
 176         return tmp;
 177 }
 178
 179 /*
 180  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 181  * store NEW in MEM.  Return the initial value in MEM.  Success is
 182  * indicated by comparing RETURN with OLD.
 183  */
 184 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 185                                       unsigned long new, int size)
 186 {
 187         unsigned long tmp = 0;
 188         unsigned long flags = 0;
 189
 190         local_irq_save(flags);
 191
 192         switch (size) {
 193         case 1:
 194                 __asm__ __volatile__
 195                         ("%0 = b%3 (z);\n\t"
 196                          "CC = %1 == %0;\n\t"
 197                          "IF !CC JUMP 1f;\n\t"
 198                          "b%3 = %2;\n\t"
 199                          "1:\n\t"
 200                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
 201                 break;
 202         case 2:
 203                 __asm__ __volatile__
 204                         ("%0 = w%3 (z);\n\t"
 205                          "CC = %1 == %0;\n\t"
 206                          "IF !CC JUMP 1f;\n\t"
 207                          "w%3 = %2;\n\t"
 208                          "1:\n\t"
 209                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
 210                 break;
 211         case 4:
 212                 __asm__ __volatile__
 213                         ("%0 = %3;\n\t"
 214                          "CC = %1 == %0;\n\t"
 215                          "IF !CC JUMP 1f;\n\t"
 216                          "%3 = %2;\n\t"
 217                          "1:\n\t"
 218                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
 219                 break;
 220         }
 221         local_irq_restore(flags);
 222         return tmp;
 223 }
 224
 225 #define cmpxchg(ptr,o,n)\
 226         ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
 227                                         (unsigned long)(n),sizeof(*(ptr))))
 228
 229 #define prepare_to_switch()     do { } while(0)
 230
 231 /*
 232  * switch_to(n) should switch tasks to task ptr, first checking that
 233  * ptr isn't the current task, in which case it does nothing.
 234  */
 235
 236 #include <asm/blackfin.h>
 237
 238 asmlinkage struct task_struct *resume(struct task_struct *prev, struct task_struct *next);
 239
 240 #define switch_to(prev,next,last) \
 241 do {    \
 242         memcpy (&task_thread_info(prev)->l1_task_info, L1_SCRATCH_TASK_INFO, \
 243                 sizeof *L1_SCRATCH_TASK_INFO); \
 244         memcpy (L1_SCRATCH_TASK_INFO, &task_thread_info(next)->l1_task_info, \
 245                 sizeof *L1_SCRATCH_TASK_INFO); \
 246         (last) = resume (prev, next);   \
 247 } while (0)
 248
 249 #endif                          /* _BLACKFIN_SYSTEM_H */