include/asm-arm/locks.h

   1 /*
   2  *  linux/include/asm-arm/locks.h
   3  *
   4  *  Copyright (C) 2000 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Interrupt safe locking assembler.
  11  */
  12 #ifndef __ASM_PROC_LOCKS_H
  13 #define __ASM_PROC_LOCKS_H
  14
  15 #if __LINUX_ARM_ARCH__ >= 6
  16
  17 #define __down_op(ptr,fail)                     \
  18         ({                                      \
  19         __asm__ __volatile__(                   \
  20         "@ down_op\n"                           \
  21 "1:     ldrex   lr, [%0]\n"                     \
  22 "       sub     lr, lr, %1\n"                   \
  23 "       strex   ip, lr, [%0]\n"                 \
  24 "       teq     ip, #0\n"                       \
  25 "       bne     1b\n"                           \
  26 "       teq     lr, #0\n"                       \
  27 "       movmi   ip, %0\n"                       \
  28 "       blmi    " #fail                         \
  29         :                                       \
  30         : "r" (ptr), "I" (1)                    \
  31         : "ip", "lr", "cc", "memory");          \
  32         })
  33
  34 #define __down_op_ret(ptr,fail)                 \
  35         ({                                      \
  36                 unsigned int ret;               \
  37         __asm__ __volatile__(                   \
  38         "@ down_op_ret\n"                       \
  39 "1:     ldrex   lr, [%1]\n"                     \
  40 "       sub     lr, lr, %2\n"                   \
  41 "       strex   ip, lr, [%1]\n"                 \
  42 "       teq     ip, #0\n"                       \
  43 "       bne     1b\n"                           \
  44 "       teq     lr, #0\n"                       \
  45 "       movmi   ip, %1\n"                       \
  46 "       movpl   ip, #0\n"                       \
  47 "       blmi    " #fail "\n"                    \
  48 "       mov     %0, ip"                         \
  49         : "=&r" (ret)                           \
  50         : "r" (ptr), "I" (1)                    \
  51         : "ip", "lr", "cc", "memory");          \
  52         ret;                                    \
  53         })
  54
  55 #define __up_op(ptr,wake)                       \
  56         ({                                      \
  57         __asm__ __volatile__(                   \
  58         "@ up_op\n"                             \
  59 "1:     ldrex   lr, [%0]\n"                     \
  60 "       add     lr, lr, %1\n"                   \
  61 "       strex   ip, lr, [%0]\n"                 \
  62 "       teq     ip, #0\n"                       \
  63 "       bne     1b\n"                           \
  64 "       teq     lr, #0\n"                       \
  65 "       movle   ip, %0\n"                       \
  66 "       blle    " #wake                         \
  67         :                                       \
  68         : "r" (ptr), "I" (1)                    \
  69         : "ip", "lr", "cc", "memory");          \
  70         })
  71
  72 /*
  73  * The value 0x01000000 supports up to 128 processors and
  74  * lots of processes.  BIAS must be chosen such that sub'ing
  75  * BIAS once per CPU will result in the long remaining
  76  * negative.
  77  */
  78 #define RW_LOCK_BIAS      0x01000000
  79 #define RW_LOCK_BIAS_STR "0x01000000"
  80
  81 #define __down_op_write(ptr,fail)               \
  82         ({                                      \
  83         __asm__ __volatile__(                   \
  84         "@ down_op_write\n"                     \
  85 "1:     ldrex   lr, [%0]\n"                     \
  86 "       sub     lr, lr, %1\n"                   \
  87 "       strex   ip, lr, [%0]\n"                 \
  88 "       teq     ip, #0\n"                       \
  89 "       bne     1b\n"                           \
  90 "       teq     lr, #0\n"                       \
  91 "       movne   ip, %0\n"                       \
  92 "       blne    " #fail                         \
  93         :                                       \
  94         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
  95         : "ip", "lr", "cc", "memory");          \
  96         })
  97
  98 #define __up_op_write(ptr,wake)                 \
  99         ({                                      \
 100         __asm__ __volatile__(                   \
 101         "@ up_op_read\n"                        \
 102 "1:     ldrex   lr, [%0]\n"                     \
 103 "       add     lr, lr, %1\n"                   \
 104 "       strex   ip, lr, [%0]\n"                 \
 105 "       teq     ip, #0\n"                       \
 106 "       bne     1b\n"                           \
 107 "       movcs   ip, %0\n"                       \
 108 "       blcs    " #wake                         \
 109         :                                       \
 110         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
 111         : "ip", "lr", "cc", "memory");          \
 112         })
 113
 114 #define __down_op_read(ptr,fail)                \
 115         __down_op(ptr, fail)
 116
 117 #define __up_op_read(ptr,wake)                  \
 118         ({                                      \
 119         __asm__ __volatile__(                   \
 120         "@ up_op_read\n"                        \
 121 "1:     ldrex   lr, [%0]\n"                     \
 122 "       add     lr, lr, %1\n"                   \
 123 "       strex   ip, lr, [%0]\n"                 \
 124 "       teq     ip, #0\n"                       \
 125 "       bne     1b\n"                           \
 126 "       teq     lr, #0\n"                       \
 127 "       moveq   ip, %0\n"                       \
 128 "       bleq    " #wake                         \
 129         :                                       \
 130         : "r" (ptr), "I" (1)                    \
 131         : "ip", "lr", "cc", "memory");          \
 132         })
 133
 134 #else
 135
 136 #define __down_op(ptr,fail)                     \
 137         ({                                      \
 138         __asm__ __volatile__(                   \
 139         "@ down_op\n"                           \
 140 "       mrs     ip, cpsr\n"                     \
 141 "       orr     lr, ip, #128\n"                 \
 142 "       msr     cpsr_c, lr\n"                   \
 143 "       ldr     lr, [%0]\n"                     \
 144 "       subs    lr, lr, %1\n"                   \
 145 "       str     lr, [%0]\n"                     \
 146 "       msr     cpsr_c, ip\n"                   \
 147 "       movmi   ip, %0\n"                       \
 148 "       blmi    " #fail                         \
 149         :                                       \
 150         : "r" (ptr), "I" (1)                    \
 151         : "ip", "lr", "cc", "memory");          \
 152         })
 153
 154 #define __down_op_ret(ptr,fail)                 \
 155         ({                                      \
 156                 unsigned int ret;               \
 157         __asm__ __volatile__(                   \
 158         "@ down_op_ret\n"                       \
 159 "       mrs     ip, cpsr\n"                     \
 160 "       orr     lr, ip, #128\n"                 \
 161 "       msr     cpsr_c, lr\n"                   \
 162 "       ldr     lr, [%1]\n"                     \
 163 "       subs    lr, lr, %2\n"                   \
 164 "       str     lr, [%1]\n"                     \
 165 "       msr     cpsr_c, ip\n"                   \
 166 "       movmi   ip, %1\n"                       \
 167 "       movpl   ip, #0\n"                       \
 168 "       blmi    " #fail "\n"                    \
 169 "       mov     %0, ip"                         \
 170         : "=&r" (ret)                           \
 171         : "r" (ptr), "I" (1)                    \
 172         : "ip", "lr", "cc", "memory");          \
 173         ret;                                    \
 174         })
 175
 176 #define __up_op(ptr,wake)                       \
 177         ({                                      \
 178         __asm__ __volatile__(                   \
 179         "@ up_op\n"                             \
 180 "       mrs     ip, cpsr\n"                     \
 181 "       orr     lr, ip, #128\n"                 \
 182 "       msr     cpsr_c, lr\n"                   \
 183 "       ldr     lr, [%0]\n"                     \
 184 "       adds    lr, lr, %1\n"                   \
 185 "       str     lr, [%0]\n"                     \
 186 "       msr     cpsr_c, ip\n"                   \
 187 "       movle   ip, %0\n"                       \
 188 "       blle    " #wake                         \
 189         :                                       \
 190         : "r" (ptr), "I" (1)                    \
 191         : "ip", "lr", "cc", "memory");          \
 192         })
 193
 194 /*
 195  * The value 0x01000000 supports up to 128 processors and
 196  * lots of processes.  BIAS must be chosen such that sub'ing
 197  * BIAS once per CPU will result in the long remaining
 198  * negative.
 199  */
 200 #define RW_LOCK_BIAS      0x01000000
 201 #define RW_LOCK_BIAS_STR "0x01000000"
 202
 203 #define __down_op_write(ptr,fail)               \
 204         ({                                      \
 205         __asm__ __volatile__(                   \
 206         "@ down_op_write\n"                     \
 207 "       mrs     ip, cpsr\n"                     \
 208 "       orr     lr, ip, #128\n"                 \
 209 "       msr     cpsr_c, lr\n"                   \
 210 "       ldr     lr, [%0]\n"                     \
 211 "       subs    lr, lr, %1\n"                   \
 212 "       str     lr, [%0]\n"                     \
 213 "       msr     cpsr_c, ip\n"                   \
 214 "       movne   ip, %0\n"                       \
 215 "       blne    " #fail                         \
 216         :                                       \
 217         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
 218         : "ip", "lr", "cc", "memory");          \
 219         })
 220
 221 #define __up_op_write(ptr,wake)                 \
 222         ({                                      \
 223         __asm__ __volatile__(                   \
 224         "@ up_op_read\n"                        \
 225 "       mrs     ip, cpsr\n"                     \
 226 "       orr     lr, ip, #128\n"                 \
 227 "       msr     cpsr_c, lr\n"                   \
 228 "       ldr     lr, [%0]\n"                     \
 229 "       adds    lr, lr, %1\n"                   \
 230 "       str     lr, [%0]\n"                     \
 231 "       msr     cpsr_c, ip\n"                   \
 232 "       movcs   ip, %0\n"                       \
 233 "       blcs    " #wake                         \
 234         :                                       \
 235         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
 236         : "ip", "lr", "cc", "memory");          \
 237         })
 238
 239 #define __down_op_read(ptr,fail)                \
 240         __down_op(ptr, fail)
 241
 242 #define __up_op_read(ptr,wake)                  \
 243         ({                                      \
 244         __asm__ __volatile__(                   \
 245         "@ up_op_read\n"                        \
 246 "       mrs     ip, cpsr\n"                     \
 247 "       orr     lr, ip, #128\n"                 \
 248 "       msr     cpsr_c, lr\n"                   \
 249 "       ldr     lr, [%0]\n"                     \
 250 "       adds    lr, lr, %1\n"                   \
 251 "       str     lr, [%0]\n"                     \
 252 "       msr     cpsr_c, ip\n"                   \
 253 "       moveq   ip, %0\n"                       \
 254 "       bleq    " #wake                         \
 255         :                                       \
 256         : "r" (ptr), "I" (1)                    \
 257         : "ip", "lr", "cc", "memory");          \
 258         })
 259
 260 #endif
 261
 262 #endif