include/asm-frv/system.h

   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/config.h> /* get configuration macros */
  16 #include <linux/linkage.h>
  17 #include <asm/atomic.h>
  18
  19 struct thread_struct;
  20
  21 #define prepare_to_switch()    do { } while(0)
  22
  23 /*
  24  * switch_to(prev, next) should switch from task `prev' to `next'
  25  * `prev' will never be the same as `next'.
  26  * The `mb' is to tell GCC not to cache `current' across this call.
  27  */
  28 extern asmlinkage
  29 struct task_struct *__switch_to(struct thread_struct *prev_thread,
  30                                 struct thread_struct *next_thread,
  31                                 struct task_struct *prev);
  32
  33 #define switch_to(prev, next, last)                                     \
  34 do {                                                                    \
  35         (prev)->thread.sched_lr =                                       \
  36                 (unsigned long) __builtin_return_address(0);            \
  37         (last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \
  38         mb();                                                           \
  39 } while(0)
  40
  41 /*
  42  * interrupt flag manipulation
  43  * - use virtual interrupt management since touching the PSR is slow
  44  *   - ICC2.Z: T if interrupts virtually disabled
  45  *   - ICC2.C: F if interrupts really disabled
  46  * - if Z==1 upon interrupt:
  47  *   - C is set to 0
  48  *   - interrupts are really disabled
  49  *   - entry.S returns immediately
  50  * - uses TIHI (TRAP if Z==0 && C==0) #2 to really reenable interrupts
  51  *   - if taken, the trap:
  52  *     - sets ICC2.C
  53  *     - enables interrupts
  54  */
  55 #define local_irq_disable()                                     \
  56 do {                                                            \
  57         /* set Z flag, but don't change the C flag */           \
  58         asm volatile("  andcc   gr0,gr0,gr0,icc2        \n"     \
  59                      :                                          \
  60                      :                                          \
  61                      : "memory", "icc2"                         \
  62                      );                                         \
  63 } while(0)
  64
  65 #define local_irq_enable()                                      \
  66 do {                                                            \
  67         /* clear Z flag and then test the C flag */             \
  68         asm volatile("  oricc   gr0,#1,gr0,icc2         \n"     \
  69                      "  tihi    icc2,gr0,#2             \n"     \
  70                      :                                          \
  71                      :                                          \
  72                      : "memory", "icc2"                         \
  73                      );                                         \
  74 } while(0)
  75
  76 #define local_save_flags(flags)                                 \
  77 do {                                                            \
  78         typecheck(unsigned long, flags);                        \
  79         asm volatile("movsg ccr,%0"                             \
  80                      : "=r"(flags)                              \
  81                      :                                          \
  82                      : "memory");                               \
  83                                                                 \
  84         /* shift ICC2.Z to bit 0 */                             \
  85         flags >>= 26;                                           \
  86                                                                 \
  87         /* make flags 1 if interrupts disabled, 0 otherwise */  \
  88         flags &= 1UL;                                           \
  89 } while(0)
  90
  91 #define irqs_disabled() \
  92         ({unsigned long flags; local_save_flags(flags); flags; })
  93
  94 #define local_irq_save(flags)                   \
  95 do {                                            \
  96         typecheck(unsigned long, flags);        \
  97         local_save_flags(flags);                \
  98         local_irq_disable();                    \
  99 } while(0)
 100
 101 #define local_irq_restore(flags)                                        \
 102 do {                                                                    \
 103         typecheck(unsigned long, flags);                                \
 104                                                                         \
 105         /* load the Z flag by turning 1 if disabled into 0 if disabled  \
 106          * and thus setting the Z flag but not the C flag */            \
 107         asm volatile("  xoricc  %0,#1,gr0,icc2          \n"             \
 108                      /* then test Z=0 and C=0 */                        \
 109                      "  tihi    icc2,gr0,#2             \n"             \
 110                      :                                                  \
 111                      : "r"(flags)                                       \
 112                      : "memory", "icc2"                                 \
 113                      );                                                 \
 114                                                                         \
 115 } while(0)
 116
 117 /*
 118  * real interrupt flag manipulation
 119  */
 120 #define __local_irq_disable()                           \
 121 do {                                                    \
 122         unsigned long psr;                              \
 123         asm volatile("  movsg   psr,%0          \n"     \
 124                      "  andi    %0,%2,%0        \n"     \
 125                      "  ori     %0,%1,%0        \n"     \
 126                      "  movgs   %0,psr          \n"     \
 127                      : "=r"(psr)                        \
 128                      : "i" (PSR_PIL_14), "i" (~PSR_PIL) \
 129                      : "memory");                       \
 130 } while(0)
 131
 132 #define __local_irq_enable()                            \
 133 do {                                                    \
 134         unsigned long psr;                              \
 135         asm volatile("  movsg   psr,%0          \n"     \
 136                      "  andi    %0,%1,%0        \n"     \
 137                      "  movgs   %0,psr          \n"     \
 138                      : "=r"(psr)                        \
 139                      : "i" (~PSR_PIL)                   \
 140                      : "memory");                       \
 141 } while(0)
 142
 143 #define __local_save_flags(flags)               \
 144 do {                                            \
 145         typecheck(unsigned long, flags);        \
 146         asm("movsg psr,%0"                      \
 147             : "=r"(flags)                       \
 148             :                                   \
 149             : "memory");                        \
 150 } while(0)
 151
 152 #define __local_irq_save(flags)                         \
 153 do {                                                    \
 154         unsigned long npsr;                             \
 155         typecheck(unsigned long, flags);                \
 156         asm volatile("  movsg   psr,%0          \n"     \
 157                      "  andi    %0,%3,%1        \n"     \
 158                      "  ori     %1,%2,%1        \n"     \
 159                      "  movgs   %1,psr          \n"     \
 160                      : "=r"(flags), "=r"(npsr)          \
 161                      : "i" (PSR_PIL_14), "i" (~PSR_PIL) \
 162                      : "memory");                       \
 163 } while(0)
 164
 165 #define __local_irq_restore(flags)                      \
 166 do {                                                    \
 167         typecheck(unsigned long, flags);                \
 168         asm volatile("  movgs   %0,psr          \n"     \
 169                      :                                  \
 170                      : "r" (flags)                      \
 171                      : "memory");                       \
 172 } while(0)
 173
 174 #define __irqs_disabled() \
 175         ((__get_PSR() & PSR_PIL) >= PSR_PIL_14)
 176
 177 /*
 178  * Force strict CPU ordering.
 179  */
 180 #define nop()                   asm volatile ("nop"::)
 181 #define mb()                    asm volatile ("membar" : : :"memory")
 182 #define rmb()                   asm volatile ("membar" : : :"memory")
 183 #define wmb()                   asm volatile ("membar" : : :"memory")
 184 #define set_mb(var, value)      do { var = value; mb(); } while (0)
 185 #define set_wmb(var, value)     do { var = value; wmb(); } while (0)
 186
 187 #define smp_mb()                mb()
 188 #define smp_rmb()               rmb()
 189 #define smp_wmb()               wmb()
 190
 191 #define read_barrier_depends()          do {} while(0)
 192 #define smp_read_barrier_depends()      read_barrier_depends()
 193
 194 #define HARD_RESET_NOW()                        \
 195 do {                                            \
 196         cli();                                  \
 197 } while(1)
 198
 199 extern void die_if_kernel(const char *, ...) __attribute__((format(printf, 1, 2)));
 200 extern void free_initmem(void);
 201
 202 #define arch_align_stack(x) (x)
 203
 204 #endif /* _ASM_SYSTEM_H */