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   1 /* system.h: FR-V CPU control definitions
   2  *
   3  * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #ifndef _ASM_SYSTEM_H
  13 #define _ASM_SYSTEM_H
  14
  15 #include <linux/types.h>
  16 #include <linux/linkage.h>
  17
  18 struct thread_struct;
  19
  20 /*
  21  * switch_to(prev, next) should switch from task `prev' to `next'
  22  * `prev' will never be the same as `next'.
  23  * The `mb' is to tell GCC not to cache `current' across this call.
  24  */
  25 extern asmlinkage
  26 struct task_struct *__switch_to(struct thread_struct *prev_thread,
  27                                 struct thread_struct *next_thread,
  28                                 struct task_struct *prev);
  29
  30 #define switch_to(prev, next, last)                                     \
  31 do {                                                                    \
  32         (prev)->thread.sched_lr =                                       \
  33                 (unsigned long) __builtin_return_address(0);            \
  34         (last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \
  35         mb();                                                           \
  36 } while(0)
  37
  38 /*
  39  * interrupt flag manipulation
  40  * - use virtual interrupt management since touching the PSR is slow
  41  *   - ICC2.Z: T if interrupts virtually disabled
  42  *   - ICC2.C: F if interrupts really disabled
  43  * - if Z==1 upon interrupt:
  44  *   - C is set to 0
  45  *   - interrupts are really disabled
  46  *   - entry.S returns immediately
  47  * - uses TIHI (TRAP if Z==0 && C==0) #2 to really reenable interrupts
  48  *   - if taken, the trap:
  49  *     - sets ICC2.C
  50  *     - enables interrupts
  51  */
  52 #define local_irq_disable()                                     \
  53 do {                                                            \
  54         /* set Z flag, but don't change the C flag */           \
  55         asm volatile("  andcc   gr0,gr0,gr0,icc2        \n"     \
  56                      :                                          \
  57                      :                                          \
  58                      : "memory", "icc2"                         \
  59                      );                                         \
  60 } while(0)
  61
  62 #define local_irq_enable()                                      \
  63 do {                                                            \
  64         /* clear Z flag and then test the C flag */             \
  65         asm volatile("  oricc   gr0,#1,gr0,icc2         \n"     \
  66                      "  tihi    icc2,gr0,#2             \n"     \
  67                      :                                          \
  68                      :                                          \
  69                      : "memory", "icc2"                         \
  70                      );                                         \
  71 } while(0)
  72
  73 #define local_save_flags(flags)                                 \
  74 do {                                                            \
  75         typecheck(unsigned long, flags);                        \
  76         asm volatile("movsg ccr,%0"                             \
  77                      : "=r"(flags)                              \
  78                      :                                          \
  79                      : "memory");                               \
  80                                                                 \
  81         /* shift ICC2.Z to bit 0 */                             \
  82         flags >>= 26;                                           \
  83                                                                 \
  84         /* make flags 1 if interrupts disabled, 0 otherwise */  \
  85         flags &= 1UL;                                           \
  86 } while(0)
  87
  88 #define irqs_disabled() \
  89         ({unsigned long flags; local_save_flags(flags); flags; })
  90
  91 #define local_irq_save(flags)                   \
  92 do {                                            \
  93         typecheck(unsigned long, flags);        \
  94         local_save_flags(flags);                \
  95         local_irq_disable();                    \
  96 } while(0)
  97
  98 #define local_irq_restore(flags)                                        \
  99 do {                                                                    \
 100         typecheck(unsigned long, flags);                                \
 101                                                                         \
 102         /* load the Z flag by turning 1 if disabled into 0 if disabled  \
 103          * and thus setting the Z flag but not the C flag */            \
 104         asm volatile("  xoricc  %0,#1,gr0,icc2          \n"             \
 105                      /* then test Z=0 and C=0 */                        \
 106                      "  tihi    icc2,gr0,#2             \n"             \
 107                      :                                                  \
 108                      : "r"(flags)                                       \
 109                      : "memory", "icc2"                                 \
 110                      );                                                 \
 111                                                                         \
 112 } while(0)
 113
 114 /*
 115  * real interrupt flag manipulation
 116  */
 117 #define __local_irq_disable()                           \
 118 do {                                                    \
 119         unsigned long psr;                              \
 120         asm volatile("  movsg   psr,%0          \n"     \
 121                      "  andi    %0,%2,%0        \n"     \
 122                      "  ori     %0,%1,%0        \n"     \
 123                      "  movgs   %0,psr          \n"     \
 124                      : "=r"(psr)                        \
 125                      : "i" (PSR_PIL_14), "i" (~PSR_PIL) \
 126                      : "memory");                       \
 127 } while(0)
 128
 129 #define __local_irq_enable()                            \
 130 do {                                                    \
 131         unsigned long psr;                              \
 132         asm volatile("  movsg   psr,%0          \n"     \
 133                      "  andi    %0,%1,%0        \n"     \
 134                      "  movgs   %0,psr          \n"     \
 135                      : "=r"(psr)                        \
 136                      : "i" (~PSR_PIL)                   \
 137                      : "memory");                       \
 138 } while(0)
 139
 140 #define __local_save_flags(flags)               \
 141 do {                                            \
 142         typecheck(unsigned long, flags);        \
 143         asm("movsg psr,%0"                      \
 144             : "=r"(flags)                       \
 145             :                                   \
 146             : "memory");                        \
 147 } while(0)
 148
 149 #define __local_irq_save(flags)                         \
 150 do {                                                    \
 151         unsigned long npsr;                             \
 152         typecheck(unsigned long, flags);                \
 153         asm volatile("  movsg   psr,%0          \n"     \
 154                      "  andi    %0,%3,%1        \n"     \
 155                      "  ori     %1,%2,%1        \n"     \
 156                      "  movgs   %1,psr          \n"     \
 157                      : "=r"(flags), "=r"(npsr)          \
 158                      : "i" (PSR_PIL_14), "i" (~PSR_PIL) \
 159                      : "memory");                       \
 160 } while(0)
 161
 162 #define __local_irq_restore(flags)                      \
 163 do {                                                    \
 164         typecheck(unsigned long, flags);                \
 165         asm volatile("  movgs   %0,psr          \n"     \
 166                      :                                  \
 167                      : "r" (flags)                      \
 168                      : "memory");                       \
 169 } while(0)
 170
 171 #define __irqs_disabled() \
 172         ((__get_PSR() & PSR_PIL) >= PSR_PIL_14)
 173
 174 /*
 175  * Force strict CPU ordering.
 176  */
 177 #define nop()                   asm volatile ("nop"::)
 178 #define mb()                    asm volatile ("membar" : : :"memory")
 179 #define rmb()                   asm volatile ("membar" : : :"memory")
 180 #define wmb()                   asm volatile ("membar" : : :"memory")
 181 #define set_mb(var, value)      do { var = value; mb(); } while (0)
 182
 183 #define smp_mb()                mb()
 184 #define smp_rmb()               rmb()
 185 #define smp_wmb()               wmb()
 186
 187 #define read_barrier_depends()          do {} while(0)
 188 #define smp_read_barrier_depends()      read_barrier_depends()
 189
 190 #define HARD_RESET_NOW()                        \
 191 do {                                            \
 192         cli();                                  \
 193 } while(1)
 194
 195 extern void die_if_kernel(const char *, ...) __attribute__((format(printf, 1, 2)));
 196 extern void free_initmem(void);
 197
 198 #define arch_align_stack(x) (x)
 199
 200 /*****************************************************************************/
 201 /*
 202  * compare and conditionally exchange value with memory
 203  * - if (*ptr == test) then orig = *ptr; *ptr = test;
 204  * - if (*ptr != test) then orig = *ptr;
 205  */
 206 #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
 207
 208 #define cmpxchg(ptr, test, new)                                                 \
 209 ({                                                                              \
 210         __typeof__(ptr) __xg_ptr = (ptr);                                       \
 211         __typeof__(*(ptr)) __xg_orig, __xg_tmp;                                 \
 212         __typeof__(*(ptr)) __xg_test = (test);                                  \
 213         __typeof__(*(ptr)) __xg_new = (new);                                    \
 214                                                                                 \
 215         switch (sizeof(__xg_orig)) {                                            \
 216         case 4:                                                                 \
 217                 asm volatile(                                                   \
 218                         "0:                                             \n"     \
 219                         "       orcc            gr0,gr0,gr0,icc3        \n"     \
 220                         "       ckeq            icc3,cc7                \n"     \
 221                         "       ld.p            %M0,%1                  \n"     \
 222                         "       orcr            cc7,cc7,cc3             \n"     \
 223                         "       sub%I4cc        %1,%4,%2,icc0           \n"     \
 224                         "       bne             icc0,#0,1f              \n"     \
 225                         "       cst.p           %3,%M0          ,cc3,#1 \n"     \
 226                         "       corcc           gr29,gr29,gr0   ,cc3,#1 \n"     \
 227                         "       beq             icc3,#0,0b              \n"     \
 228                         "1:                                             \n"     \
 229                         : "+U"(*__xg_ptr), "=&r"(__xg_orig), "=&r"(__xg_tmp)    \
 230                         : "r"(__xg_new), "NPr"(__xg_test)                       \
 231                         : "memory", "cc7", "cc3", "icc3", "icc0"                \
 232                         );                                                      \
 233                 break;                                                          \
 234                                                                                 \
 235         default:                                                                \
 236                 __xg_orig = 0;                                                  \
 237                 asm volatile("break");                                          \
 238                 break;                                                          \
 239         }                                                                       \
 240                                                                                 \
 241         __xg_orig;                                                              \
 242 })
 243
 244 #else
 245
 246 extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new);
 247
 248 #define cmpxchg(ptr, test, new)                                                 \
 249 ({                                                                              \
 250         __typeof__(ptr) __xg_ptr = (ptr);                                       \
 251         __typeof__(*(ptr)) __xg_orig;                                           \
 252         __typeof__(*(ptr)) __xg_test = (test);                                  \
 253         __typeof__(*(ptr)) __xg_new = (new);                                    \
 254                                                                                 \
 255         switch (sizeof(__xg_orig)) {                                            \
 256         case 4: __xg_orig = (__force __typeof__(*ptr))                          \
 257                         __cmpxchg_32((__force uint32_t *)__xg_ptr,              \
 258                                          (__force uint32_t)__xg_test,           \
 259                                          (__force uint32_t)__xg_new); break;    \
 260         default:                                                                \
 261                 __xg_orig = 0;                                                  \
 262                 asm volatile("break");                                          \
 263                 break;                                                          \
 264         }                                                                       \
 265                                                                                 \
 266         __xg_orig;                                                              \
 267 })
 268
 269 #endif
 270
 271
 272 #endif /* _ASM_SYSTEM_H */