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 #include <asm/mach/anomaly.h>
  40
  41 /*
  42  * Interrupt configuring macros.
  43  */
  44
  45 extern unsigned long irq_flags;
  46
  47 #define local_irq_enable() \
  48         __asm__ __volatile__( \
  49                 "sti %0;" \
  50                 : \
  51                 : "d" (irq_flags) \
  52         )
  53
  54 #define local_irq_disable() \
  55         do { \
  56                 int __tmp_dummy; \
  57                 __asm__ __volatile__( \
  58                         "cli %0;" \
  59                         : "=d" (__tmp_dummy) \
  60                 ); \
  61         } while (0)
  62
  63 #if ANOMALY_05000244 && defined(CONFIG_BFIN_ICACHE)
  64 # define NOP_PAD_ANOMALY_05000244 "nop; nop;"
  65 #else
  66 # define NOP_PAD_ANOMALY_05000244
  67 #endif
  68
  69 #define idle_with_irq_disabled() \
  70         __asm__ __volatile__( \
  71                 NOP_PAD_ANOMALY_05000244 \
  72                 ".align 8;" \
  73                 "sti %0;" \
  74                 "idle;" \
  75                 : \
  76                 : "d" (irq_flags) \
  77         )
  78
  79 #ifdef CONFIG_DEBUG_HWERR
  80 # define __save_and_cli(x) \
  81         __asm__ __volatile__( \
  82                 "cli %0;" \
  83                 "sti %1;" \
  84                 : "=&d" (x) \
  85                 : "d" (0x3F) \
  86         )
  87 #else
  88 # define __save_and_cli(x) \
  89         __asm__ __volatile__( \
  90                 "cli %0;" \
  91                 : "=&d" (x) \
  92         )
  93 #endif
  94
  95 #define local_save_flags(x) \
  96         __asm__ __volatile__( \
  97                 "cli %0;" \
  98                 "sti %0;" \
  99                 : "=d" (x) \
 100         )
 101
 102 #ifdef CONFIG_DEBUG_HWERR
 103 #define irqs_enabled_from_flags(x) (((x) & ~0x3f) != 0)
 104 #else
 105 #define irqs_enabled_from_flags(x) ((x) != 0x1f)
 106 #endif
 107
 108 #define local_irq_restore(x) \
 109         do { \
 110                 if (irqs_enabled_from_flags(x)) \
 111                         local_irq_enable(); \
 112         } while (0)
 113
 114 /* For spinlocks etc */
 115 #define local_irq_save(x) __save_and_cli(x)
 116
 117 #define irqs_disabled()                         \
 118 ({                                              \
 119         unsigned long flags;                    \
 120         local_save_flags(flags);                \
 121         !irqs_enabled_from_flags(flags);        \
 122 })
 123
 124 /*
 125  * Force strict CPU ordering.
 126  */
 127 #define nop()  asm volatile ("nop;\n\t"::)
 128 #define mb()   asm volatile (""   : : :"memory")
 129 #define rmb()  asm volatile (""   : : :"memory")
 130 #define wmb()  asm volatile (""   : : :"memory")
 131 #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
 132
 133 #define read_barrier_depends()          do { } while(0)
 134
 135 #ifdef CONFIG_SMP
 136 #define smp_mb()        mb()
 137 #define smp_rmb()       rmb()
 138 #define smp_wmb()       wmb()
 139 #define smp_read_barrier_depends()      read_barrier_depends()
 140 #else
 141 #define smp_mb()        barrier()
 142 #define smp_rmb()       barrier()
 143 #define smp_wmb()       barrier()
 144 #define smp_read_barrier_depends()      do { } while(0)
 145 #endif
 146
 147 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 148
 149 struct __xchg_dummy {
 150         unsigned long a[100];
 151 };
 152 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
 153
 154 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
 155                                    int size)
 156 {
 157         unsigned long tmp = 0;
 158         unsigned long flags = 0;
 159
 160         local_irq_save(flags);
 161
 162         switch (size) {
 163         case 1:
 164                 __asm__ __volatile__
 165                         ("%0 = b%2 (z);\n\t"
 166                          "b%2 = %1;\n\t"
 167                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 168                 break;
 169         case 2:
 170                 __asm__ __volatile__
 171                         ("%0 = w%2 (z);\n\t"
 172                          "w%2 = %1;\n\t"
 173                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 174                 break;
 175         case 4:
 176                 __asm__ __volatile__
 177                         ("%0 = %2;\n\t"
 178                          "%2 = %1;\n\t"
 179                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 180                 break;
 181         }
 182         local_irq_restore(flags);
 183         return tmp;
 184 }
 185
 186 /*
 187  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 188  * store NEW in MEM.  Return the initial value in MEM.  Success is
 189  * indicated by comparing RETURN with OLD.
 190  */
 191 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 192                                       unsigned long new, int size)
 193 {
 194         unsigned long tmp = 0;
 195         unsigned long flags = 0;
 196
 197         local_irq_save(flags);
 198
 199         switch (size) {
 200         case 1:
 201                 __asm__ __volatile__
 202                         ("%0 = b%3 (z);\n\t"
 203                          "CC = %1 == %0;\n\t"
 204                          "IF !CC JUMP 1f;\n\t"
 205                          "b%3 = %2;\n\t"
 206                          "1:\n\t"
 207                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
 208                 break;
 209         case 2:
 210                 __asm__ __volatile__
 211                         ("%0 = w%3 (z);\n\t"
 212                          "CC = %1 == %0;\n\t"
 213                          "IF !CC JUMP 1f;\n\t"
 214                          "w%3 = %2;\n\t"
 215                          "1:\n\t"
 216                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
 217                 break;
 218         case 4:
 219                 __asm__ __volatile__
 220                         ("%0 = %3;\n\t"
 221                          "CC = %1 == %0;\n\t"
 222                          "IF !CC JUMP 1f;\n\t"
 223                          "%3 = %2;\n\t"
 224                          "1:\n\t"
 225                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
 226                 break;
 227         }
 228         local_irq_restore(flags);
 229         return tmp;
 230 }
 231
 232 #define cmpxchg(ptr,o,n)\
 233         ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
 234                                         (unsigned long)(n),sizeof(*(ptr))))
 235
 236 #define prepare_to_switch()     do { } while(0)
 237
 238 /*
 239  * switch_to(n) should switch tasks to task ptr, first checking that
 240  * ptr isn't the current task, in which case it does nothing.
 241  */
 242
 243 #include <asm/blackfin.h>
 244
 245 asmlinkage struct task_struct *resume(struct task_struct *prev, struct task_struct *next);
 246
 247 #define switch_to(prev,next,last) \
 248 do {    \
 249         memcpy (&task_thread_info(prev)->l1_task_info, L1_SCRATCH_TASK_INFO, \
 250                 sizeof *L1_SCRATCH_TASK_INFO); \
 251         memcpy (L1_SCRATCH_TASK_INFO, &task_thread_info(next)->l1_task_info, \
 252                 sizeof *L1_SCRATCH_TASK_INFO); \
 253         (last) = resume (prev, next);   \
 254 } while (0)
 255
 256 #endif                          /* _BLACKFIN_SYSTEM_H */