include/asm-blackfin/system.h

   1 /*
   2  * U-boot - system.h
   3  *
   4  * Copyright (c) 2005 blackfin.uclinux.org
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  */
  24
  25 #ifndef _BLACKFIN_SYSTEM_H
  26 #define _BLACKFIN_SYSTEM_H
  27
  28 #include <linux/config.h>       /* get configuration macros */
  29 #include <asm/linkage.h>
  30 #include <asm/blackfin.h>
  31 #include <asm/segment.h>
  32 #include <asm/entry.h>
  33
  34 #define prepare_to_switch()     do { } while(0)
  35
  36 /*
  37  * switch_to(n) should switch tasks to task ptr, first checking that
  38  * ptr isn't the current task, in which case it does nothing.  This
  39  * also clears the TS-flag if the task we switched to has used the
  40  * math co-processor latest.
  41  *
  42  * 05/25/01 - Tony Kou (tonyko@lineo.ca)
  43  *
  44  * Adapted for BlackFin (ADI) by Ted Ma, Metrowerks, and Motorola GSG
  45  * Copyright (c) 2002 Arcturus Networks Inc. (www.arcturusnetworks.com)
  46  * Copyright (c) 2003 Metrowerks (www.metrowerks.com)
  47  */
  48
  49 asmlinkage void resume(void);
  50
  51 #define switch_to(prev,next,last)       {                                       \
  52         void *_last;                                                            \
  53         __asm__ __volatile__(                                                   \
  54                         "r0 = %1;\n\t"                                          \
  55                         "r1 = %2;\n\t"                                          \
  56                         "call resume;\n\t"                                      \
  57                         "%0 = r0;\n\t"                                          \
  58                         : "=d" (_last)                                          \
  59                         : "d" (prev),                                           \
  60                         "d" (next)                                              \
  61                         : "CC", "R0", "R1", "R2", "R3", "R4", "R5", "P0", "P1");\
  62                         (last) = _last;                                         \
  63 }
  64
  65 /* Force kerenl switch to user mode -- Steven Chen */
  66 #define switch_to_user_mode()   {                                               \
  67         __asm__ __volatile__(                                                   \
  68                         "call kernel_to_user_mode;\n\t"                         \
  69                         ::                                                      \
  70                         : "CC", "R0", "R1", "R2", "R3", "R4", "R5", "P0", "P1");\
  71 }
  72
  73 /*
  74  * Interrupt configuring macros.
  75  */
  76
  77 extern int irq_flags;
  78
  79 #define __sti() {                       \
  80         __asm__ __volatile__ (          \
  81                 "r3 = %0;"              \
  82                 "sti r3;"               \
  83                 ::"m"(irq_flags):"R3"); \
  84 }
  85
  86 #define __cli() {                       \
  87         __asm__ __volatile__ (          \
  88                 "cli r3;"               \
  89                 :::"R3");               \
  90 }
  91
  92 #define __save_flags(x) {               \
  93         __asm__ __volatile__ (          \
  94                 "cli r3;"               \
  95                 "%0 = r3;"              \
  96                 "sti r3;"               \
  97                 ::"m"(x):"R3");         \
  98 }
  99
 100 #define __save_and_cli(x)       {       \
 101         __asm__ __volatile__ (          \
 102                 "cli r3;"               \
 103                 "%0 = r3;"              \
 104                 ::"m"(x):"R3");         \
 105 }
 106
 107 #define __restore_flags(x) {            \
 108         __asm__ __volatile__ (          \
 109                 "r3 = %0;"              \
 110                 "sti r3;"               \
 111                 ::"m"(x):"R3");         \
 112 }
 113
 114 /* For spinlocks etc */
 115 #define local_irq_save(x)       __save_and_cli(x)
 116 #define local_irq_restore(x)    __restore_flags(x)
 117 #define local_irq_disable()     __cli()
 118 #define local_irq_enable()      __sti()
 119
 120 #define cli()                   __cli()
 121 #define sti()                   __sti()
 122 #define save_flags(x)           __save_flags(x)
 123 #define restore_flags(x)        __restore_flags(x)
 124 #define save_and_cli(x)         __save_and_cli(x)
 125
 126 /*
 127  * Force strict CPU ordering.
 128  */
 129 #define nop()                   asm volatile ("nop;\n\t"::)
 130 #define mb()                    asm volatile (""   : : :"memory")
 131 #define rmb()                   asm volatile (""   : : :"memory")
 132 #define wmb()                   asm volatile (""   : : :"memory")
 133 #define set_rmb(var, value)     do { xchg(&var, value); } while (0)
 134 #define set_mb(var, value)      set_rmb(var, value)
 135 #define set_wmb(var, value)     do { var = value; wmb(); } while (0)
 136
 137 #ifdef CONFIG_SMP
 138 #define smp_mb()                mb()
 139 #define smp_rmb()               rmb()
 140 #define smp_wmb()               wmb()
 141 #else
 142 #define smp_mb()                barrier()
 143 #define smp_rmb()               barrier()
 144 #define smp_wmb()               barrier()
 145 #endif
 146
 147 #define xchg(ptr,x)             ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 148 #define tas(ptr)                (xchg((ptr),1))
 149
 150 struct __xchg_dummy {
 151         unsigned long a[100];
 152 };
 153 #define __xg(x)                 ((volatile struct __xchg_dummy *)(x))
 154
 155 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
 156                                    int size)
 157 {
 158         unsigned long tmp;
 159         unsigned long flags = 0;
 160
 161         save_and_cli(flags);
 162
 163         switch (size) {
 164         case 1:
 165               __asm__ __volatile__("%0 = %2;\n\t" "%2 = %1;\n\t": "=&d"(tmp): "d"(x), "m"(*__xg(ptr)):"memory");
 166                 break;
 167         case 2:
 168               __asm__ __volatile__("%0 = %2;\n\t" "%2 = %1;\n\t": "=&d"(tmp): "d"(x), "m"(*__xg(ptr)):"memory");
 169                 break;
 170         case 4:
 171               __asm__ __volatile__("%0 = %2;\n\t" "%2 = %1;\n\t": "=&d"(tmp): "d"(x), "m"(*__xg(ptr)):"memory");
 172                 break;
 173         }
 174         restore_flags(flags);
 175         return tmp;
 176 }
 177
 178 /* Depend on whether Blackfin has hard reset function */
 179 /* YES it does, but it is tricky to implement - FIXME later ...MaTed--- */
 180 #define HARD_RESET_NOW() ({})
 181
 182 #endif  /* _BLACKFIN_SYSTEM_H */