include/asm-m68knommu/system.h

   1 #ifndef _M68KNOMMU_SYSTEM_H
   2 #define _M68KNOMMU_SYSTEM_H
   3
   4 #include <linux/linkage.h>
   5 #include <asm/segment.h>
   6 #include <asm/entry.h>
   7
   8 /*
   9  * switch_to(n) should switch tasks to task ptr, first checking that
  10  * ptr isn't the current task, in which case it does nothing.  This
  11  * also clears the TS-flag if the task we switched to has used the
  12  * math co-processor latest.
  13  */
  14 /*
  15  * switch_to() saves the extra registers, that are not saved
  16  * automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and
  17  * a0-a1. Some of these are used by schedule() and its predecessors
  18  * and so we might get see unexpected behaviors when a task returns
  19  * with unexpected register values.
  20  *
  21  * syscall stores these registers itself and none of them are used
  22  * by syscall after the function in the syscall has been called.
  23  *
  24  * Beware that resume now expects *next to be in d1 and the offset of
  25  * tss to be in a1. This saves a few instructions as we no longer have
  26  * to push them onto the stack and read them back right after.
  27  *
  28  * 02/17/96 - Jes Sorensen (jds@kom.auc.dk)
  29  *
  30  * Changed 96/09/19 by Andreas Schwab
  31  * pass prev in a0, next in a1, offset of tss in d1, and whether
  32  * the mm structures are shared in d2 (to avoid atc flushing).
  33  */
  34 asmlinkage void resume(void);
  35 #define switch_to(prev,next,last)                               \
  36 {                                                               \
  37   void *_last;                                                  \
  38   __asm__ __volatile__(                                         \
  39         "movel  %1, %%a0\n\t"                                   \
  40         "movel  %2, %%a1\n\t"                                   \
  41         "jbsr resume\n\t"                                       \
  42         "movel  %%d1, %0\n\t"                                   \
  43        : "=d" (_last)                                           \
  44        : "d" (prev), "d" (next)                                 \
  45        : "cc", "d0", "d1", "d2", "d3", "d4", "d5", "a0", "a1"); \
  46   (last) = _last;                                               \
  47 }
  48
  49 #ifdef CONFIG_COLDFIRE
  50 #define local_irq_enable() __asm__ __volatile__ (               \
  51         "move %/sr,%%d0\n\t"                                    \
  52         "andi.l #0xf8ff,%%d0\n\t"                               \
  53         "move %%d0,%/sr\n"                                      \
  54         : /* no outputs */                                      \
  55         :                                                       \
  56         : "cc", "%d0", "memory")
  57 #define local_irq_disable() __asm__ __volatile__ (              \
  58         "move %/sr,%%d0\n\t"                                    \
  59         "ori.l #0x0700,%%d0\n\t"                                \
  60         "move %%d0,%/sr\n"                                      \
  61         : /* no outputs */                                      \
  62         :                                                       \
  63         : "cc", "%d0", "memory")
  64 /* For spinlocks etc */
  65 #define local_irq_save(x) __asm__ __volatile__ (                \
  66         "movew %%sr,%0\n\t"                                     \
  67         "movew #0x0700,%%d0\n\t"                                \
  68         "or.l  %0,%%d0\n\t"                                     \
  69         "movew %%d0,%/sr"                                       \
  70         : "=d" (x)                                              \
  71         :                                                       \
  72         : "cc", "%d0", "memory")
  73 #else
  74
  75 /* portable version */ /* FIXME - see entry.h*/
  76 #define ALLOWINT 0xf8ff
  77
  78 #define local_irq_enable() asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory")
  79 #define local_irq_disable() asm volatile ("oriw  #0x0700,%%sr": : : "memory")
  80 #endif
  81
  82 #define local_save_flags(x) asm volatile ("movew %%sr,%0":"=d" (x) : : "memory")
  83 #define local_irq_restore(x) asm volatile ("movew %0,%%sr": :"d" (x) : "memory")
  84
  85 /* For spinlocks etc */
  86 #ifndef local_irq_save
  87 #define local_irq_save(x) do { local_save_flags(x); local_irq_disable(); } while (0)
  88 #endif
  89
  90 #define irqs_disabled()                 \
  91 ({                                      \
  92         unsigned long flags;            \
  93         local_save_flags(flags);        \
  94         ((flags & 0x0700) == 0x0700);   \
  95 })
  96
  97 #define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")
  98
  99 /*
 100  * Force strict CPU ordering.
 101  * Not really required on m68k...
 102  */
 103 #define nop()  asm volatile ("nop"::)
 104 #define mb()   asm volatile (""   : : :"memory")
 105 #define rmb()  asm volatile (""   : : :"memory")
 106 #define wmb()  asm volatile (""   : : :"memory")
 107 #define set_rmb(var, value)    do { xchg(&var, value); } while (0)
 108 #define set_mb(var, value)     set_rmb(var, value)
 109
 110 #ifdef CONFIG_SMP
 111 #define smp_mb()        mb()
 112 #define smp_rmb()       rmb()
 113 #define smp_wmb()       wmb()
 114 #define smp_read_barrier_depends()      read_barrier_depends()
 115 #else
 116 #define smp_mb()        barrier()
 117 #define smp_rmb()       barrier()
 118 #define smp_wmb()       barrier()
 119 #define smp_read_barrier_depends()      do { } while(0)
 120 #endif
 121
 122 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 123
 124 struct __xchg_dummy { unsigned long a[100]; };
 125 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
 126
 127 #ifndef CONFIG_RMW_INSNS
 128 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
 129 {
 130   unsigned long tmp, flags;
 131
 132   local_irq_save(flags);
 133
 134   switch (size) {
 135   case 1:
 136     __asm__ __volatile__
 137     ("moveb %2,%0\n\t"
 138      "moveb %1,%2"
 139     : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 140     break;
 141   case 2:
 142     __asm__ __volatile__
 143     ("movew %2,%0\n\t"
 144      "movew %1,%2"
 145     : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 146     break;
 147   case 4:
 148     __asm__ __volatile__
 149     ("movel %2,%0\n\t"
 150      "movel %1,%2"
 151     : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
 152     break;
 153   }
 154   local_irq_restore(flags);
 155   return tmp;
 156 }
 157 #else
 158 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
 159 {
 160         switch (size) {
 161             case 1:
 162                 __asm__ __volatile__
 163                         ("moveb %2,%0\n\t"
 164                          "1:\n\t"
 165                          "casb %0,%1,%2\n\t"
 166                          "jne 1b"
 167                          : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
 168                 break;
 169             case 2:
 170                 __asm__ __volatile__
 171                         ("movew %2,%0\n\t"
 172                          "1:\n\t"
 173                          "casw %0,%1,%2\n\t"
 174                          "jne 1b"
 175                          : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
 176                 break;
 177             case 4:
 178                 __asm__ __volatile__
 179                         ("movel %2,%0\n\t"
 180                          "1:\n\t"
 181                          "casl %0,%1,%2\n\t"
 182                          "jne 1b"
 183                          : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
 184                 break;
 185         }
 186         return x;
 187 }
 188 #endif
 189
 190 /*
 191  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 192  * store NEW in MEM.  Return the initial value in MEM.  Success is
 193  * indicated by comparing RETURN with OLD.
 194  */
 195 #define __HAVE_ARCH_CMPXCHG     1
 196
 197 static __inline__ unsigned long
 198 cmpxchg(volatile int *p, int old, int new)
 199 {
 200         unsigned long flags;
 201         int prev;
 202
 203         local_irq_save(flags);
 204         if ((prev = *p) == old)
 205                 *p = new;
 206         local_irq_restore(flags);
 207         return(prev);
 208 }
 209
 210
 211 #ifdef CONFIG_M68332
 212 #define HARD_RESET_NOW() ({             \
 213         local_irq_disable();            \
 214         asm("                           \
 215         movew   #0x0000, 0xfffa6a;      \
 216         reset;                          \
 217         /*movew #0x1557, 0xfffa44;*/    \
 218         /*movew #0x0155, 0xfffa46;*/    \
 219         moveal #0, %a0;                 \
 220         movec %a0, %vbr;                \
 221         moveal 0, %sp;                  \
 222         moveal 4, %a0;                  \
 223         jmp (%a0);                      \
 224         ");                             \
 225 })
 226 #endif
 227
 228 #if defined( CONFIG_M68328 ) || defined( CONFIG_M68EZ328 ) || \
 229         defined (CONFIG_M68360) || defined( CONFIG_M68VZ328 )
 230 #define HARD_RESET_NOW() ({             \
 231         local_irq_disable();            \
 232         asm("                           \
 233         moveal #0x10c00000, %a0;        \
 234         moveb #0, 0xFFFFF300;           \
 235         moveal 0(%a0), %sp;             \
 236         moveal 4(%a0), %a0;             \
 237         jmp (%a0);                      \
 238         ");                             \
 239 })
 240 #endif
 241
 242 #ifdef CONFIG_COLDFIRE
 243 #if defined(CONFIG_M5272) && defined(CONFIG_NETtel)
 244 /*
 245  * Need to account for broken early mask of 5272 silicon. So don't
 246  * jump through the original start address. Jump strait into the
 247  * known start of the FLASH code.
 248  */
 249 #define HARD_RESET_NOW() ({             \
 250         asm("                           \
 251         movew #0x2700, %sr;             \
 252         jmp 0xf0000400;                 \
 253         ");                             \
 254 })
 255 #elif defined(CONFIG_NETtel) || defined(CONFIG_eLIA) || \
 256       defined(CONFIG_DISKtel) || defined(CONFIG_SECUREEDGEMP3) || \
 257       defined(CONFIG_CLEOPATRA)
 258 #define HARD_RESET_NOW() ({             \
 259         asm("                           \
 260         movew #0x2700, %sr;             \
 261         moveal #0x10000044, %a0;        \
 262         movel #0xffffffff, (%a0);       \
 263         moveal #0x10000001, %a0;        \
 264         moveb #0x00, (%a0);             \
 265         moveal #0xf0000004, %a0;        \
 266         moveal (%a0), %a0;              \
 267         jmp (%a0);                      \
 268         ");                             \
 269 })
 270 #elif defined(CONFIG_M5272)
 271 /*
 272  * Retrieve the boot address in flash using CSBR0 and CSOR0
 273  * find the reset vector at flash_address + 4 (e.g. 0x400)
 274  * remap it in the flash's current location (e.g. 0xf0000400)
 275  * and jump there.
 276  */
 277 #define HARD_RESET_NOW() ({             \
 278         asm("                           \
 279         movew #0x2700, %%sr;            \
 280         move.l  %0+0x40,%%d0;           \
 281         and.l   %0+0x44,%%d0;           \
 282         andi.l  #0xfffff000,%%d0;       \
 283         mov.l   %%d0,%%a0;              \
 284         or.l    4(%%a0),%%d0;           \
 285         mov.l   %%d0,%%a0;              \
 286         jmp (%%a0);"                    \
 287         : /* No output */               \
 288         : "o" (*(char *)MCF_MBAR) );    \
 289 })
 290 #elif defined(CONFIG_M528x)
 291 /*
 292  * The MCF528x has a bit (SOFTRST) in memory (Reset Control Register RCR),
 293  * that when set, resets the MCF528x.
 294  */
 295 #define HARD_RESET_NOW() \
 296 ({                                              \
 297         unsigned char volatile *reset;          \
 298         asm("move.w     #0x2700, %sr");         \
 299         reset = ((volatile unsigned short *)(MCF_IPSBAR + 0x110000));   \
 300         while(1)                                \
 301         *reset |= (0x01 << 7);\
 302 })
 303 #elif defined(CONFIG_M523x)
 304 #define HARD_RESET_NOW() ({             \
 305         asm("                           \
 306         movew #0x2700, %sr;             \
 307         movel #0x01000000, %sp;         \
 308         moveal #0x40110000, %a0;        \
 309         moveb #0x80, (%a0);             \
 310         ");                             \
 311 })
 312 #elif defined(CONFIG_M520x)
 313         /*
 314          * The MCF5208 has a bit (SOFTRST) in memory (Reset Control Register
 315          * RCR), that when set, resets the MCF5208.
 316          */
 317 #define HARD_RESET_NOW()                \
 318 ({                                      \
 319         unsigned char volatile *reset;  \
 320         asm("move.w     #0x2700, %sr"); \
 321         reset = ((volatile unsigned short *)(MCF_IPSBAR + 0xA0000));    \
 322         while(1)                        \
 323                 *reset |= 0x80;         \
 324 })
 325 #else
 326 #define HARD_RESET_NOW() ({             \
 327         asm("                           \
 328         movew #0x2700, %sr;             \
 329         moveal #0x4, %a0;               \
 330         moveal (%a0), %a0;              \
 331         jmp (%a0);                      \
 332         ");                             \
 333 })
 334 #endif
 335 #endif
 336 #define arch_align_stack(x) (x)
 337
 338 #endif /* _M68KNOMMU_SYSTEM_H */