arch/m32r/include/asm/local.h

   1 #ifndef __M32R_LOCAL_H
   2 #define __M32R_LOCAL_H
   3
   4 /*
   5  *  linux/include/asm-m32r/local.h
   6  *
   7  *  M32R version:
   8  *    Copyright (C) 2001, 2002  Hitoshi Yamamoto
   9  *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
  10  *    Copyright (C) 2007  Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
  11  */
  12
  13 #include <linux/percpu.h>
  14 #include <asm/assembler.h>
  15 #include <asm/system.h>
  16 #include <asm/local.h>
  17
  18 /*
  19  * Atomic operations that C can't guarantee us.  Useful for
  20  * resource counting etc..
  21  */
  22
  23 /*
  24  * Make sure gcc doesn't try to be clever and move things around
  25  * on us. We need to use _exactly_ the address the user gave us,
  26  * not some alias that contains the same information.
  27  */
  28 typedef struct { volatile int counter; } local_t;
  29
  30 #define LOCAL_INIT(i)   { (i) }
  31
  32 /**
  33  * local_read - read local variable
  34  * @l: pointer of type local_t
  35  *
  36  * Atomically reads the value of @l.
  37  */
  38 #define local_read(l)   ((l)->counter)
  39
  40 /**
  41  * local_set - set local variable
  42  * @l: pointer of type local_t
  43  * @i: required value
  44  *
  45  * Atomically sets the value of @l to @i.
  46  */
  47 #define local_set(l, i) (((l)->counter) = (i))
  48
  49 /**
  50  * local_add_return - add long to local variable and return it
  51  * @i: long value to add
  52  * @l: pointer of type local_t
  53  *
  54  * Atomically adds @i to @l and return (@i + @l).
  55  */
  56 static inline long local_add_return(long i, local_t *l)
  57 {
  58         unsigned long flags;
  59         long result;
  60
  61         local_irq_save(flags);
  62         __asm__ __volatile__ (
  63                 "# local_add_return             \n\t"
  64                 DCACHE_CLEAR("%0", "r4", "%1")
  65                 "ld %0, @%1;                    \n\t"
  66                 "add    %0, %2;                 \n\t"
  67                 "st %0, @%1;                    \n\t"
  68                 : "=&r" (result)
  69                 : "r" (&l->counter), "r" (i)
  70                 : "memory"
  71 #ifdef CONFIG_CHIP_M32700_TS1
  72                 , "r4"
  73 #endif  /* CONFIG_CHIP_M32700_TS1 */
  74         );
  75         local_irq_restore(flags);
  76
  77         return result;
  78 }
  79
  80 /**
  81  * local_sub_return - subtract long from local variable and return it
  82  * @i: long value to subtract
  83  * @l: pointer of type local_t
  84  *
  85  * Atomically subtracts @i from @l and return (@l - @i).
  86  */
  87 static inline long local_sub_return(long i, local_t *l)
  88 {
  89         unsigned long flags;
  90         long result;
  91
  92         local_irq_save(flags);
  93         __asm__ __volatile__ (
  94                 "# local_sub_return             \n\t"
  95                 DCACHE_CLEAR("%0", "r4", "%1")
  96                 "ld %0, @%1;                    \n\t"
  97                 "sub    %0, %2;                 \n\t"
  98                 "st %0, @%1;                    \n\t"
  99                 : "=&r" (result)
 100                 : "r" (&l->counter), "r" (i)
 101                 : "memory"
 102 #ifdef CONFIG_CHIP_M32700_TS1
 103                 , "r4"
 104 #endif  /* CONFIG_CHIP_M32700_TS1 */
 105         );
 106         local_irq_restore(flags);
 107
 108         return result;
 109 }
 110
 111 /**
 112  * local_add - add long to local variable
 113  * @i: long value to add
 114  * @l: pointer of type local_t
 115  *
 116  * Atomically adds @i to @l.
 117  */
 118 #define local_add(i, l) ((void) local_add_return((i), (l)))
 119
 120 /**
 121  * local_sub - subtract the local variable
 122  * @i: long value to subtract
 123  * @l: pointer of type local_t
 124  *
 125  * Atomically subtracts @i from @l.
 126  */
 127 #define local_sub(i, l) ((void) local_sub_return((i), (l)))
 128
 129 /**
 130  * local_sub_and_test - subtract value from variable and test result
 131  * @i: integer value to subtract
 132  * @l: pointer of type local_t
 133  *
 134  * Atomically subtracts @i from @l and returns
 135  * true if the result is zero, or false for all
 136  * other cases.
 137  */
 138 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
 139
 140 /**
 141  * local_inc_return - increment local variable and return it
 142  * @l: pointer of type local_t
 143  *
 144  * Atomically increments @l by 1 and returns the result.
 145  */
 146 static inline long local_inc_return(local_t *l)
 147 {
 148         unsigned long flags;
 149         long result;
 150
 151         local_irq_save(flags);
 152         __asm__ __volatile__ (
 153                 "# local_inc_return             \n\t"
 154                 DCACHE_CLEAR("%0", "r4", "%1")
 155                 "ld %0, @%1;                    \n\t"
 156                 "addi   %0, #1;                 \n\t"
 157                 "st %0, @%1;                    \n\t"
 158                 : "=&r" (result)
 159                 : "r" (&l->counter)
 160                 : "memory"
 161 #ifdef CONFIG_CHIP_M32700_TS1
 162                 , "r4"
 163 #endif  /* CONFIG_CHIP_M32700_TS1 */
 164         );
 165         local_irq_restore(flags);
 166
 167         return result;
 168 }
 169
 170 /**
 171  * local_dec_return - decrement local variable and return it
 172  * @l: pointer of type local_t
 173  *
 174  * Atomically decrements @l by 1 and returns the result.
 175  */
 176 static inline long local_dec_return(local_t *l)
 177 {
 178         unsigned long flags;
 179         long result;
 180
 181         local_irq_save(flags);
 182         __asm__ __volatile__ (
 183                 "# local_dec_return             \n\t"
 184                 DCACHE_CLEAR("%0", "r4", "%1")
 185                 "ld %0, @%1;                    \n\t"
 186                 "addi   %0, #-1;                \n\t"
 187                 "st %0, @%1;                    \n\t"
 188                 : "=&r" (result)
 189                 : "r" (&l->counter)
 190                 : "memory"
 191 #ifdef CONFIG_CHIP_M32700_TS1
 192                 , "r4"
 193 #endif  /* CONFIG_CHIP_M32700_TS1 */
 194         );
 195         local_irq_restore(flags);
 196
 197         return result;
 198 }
 199
 200 /**
 201  * local_inc - increment local variable
 202  * @l: pointer of type local_t
 203  *
 204  * Atomically increments @l by 1.
 205  */
 206 #define local_inc(l) ((void)local_inc_return(l))
 207
 208 /**
 209  * local_dec - decrement local variable
 210  * @l: pointer of type local_t
 211  *
 212  * Atomically decrements @l by 1.
 213  */
 214 #define local_dec(l) ((void)local_dec_return(l))
 215
 216 /**
 217  * local_inc_and_test - increment and test
 218  * @l: pointer of type local_t
 219  *
 220  * Atomically increments @l by 1
 221  * and returns true if the result is zero, or false for all
 222  * other cases.
 223  */
 224 #define local_inc_and_test(l) (local_inc_return(l) == 0)
 225
 226 /**
 227  * local_dec_and_test - decrement and test
 228  * @l: pointer of type local_t
 229  *
 230  * Atomically decrements @l by 1 and
 231  * returns true if the result is 0, or false for all
 232  * other cases.
 233  */
 234 #define local_dec_and_test(l) (local_dec_return(l) == 0)
 235
 236 /**
 237  * local_add_negative - add and test if negative
 238  * @l: pointer of type local_t
 239  * @i: integer value to add
 240  *
 241  * Atomically adds @i to @l and returns true
 242  * if the result is negative, or false when
 243  * result is greater than or equal to zero.
 244  */
 245 #define local_add_negative(i, l) (local_add_return((i), (l)) < 0)
 246
 247 #define local_cmpxchg(l, o, n) (cmpxchg_local(&((l)->counter), (o), (n)))
 248 #define local_xchg(v, new) (xchg_local(&((l)->counter), new))
 249
 250 /**
 251  * local_add_unless - add unless the number is a given value
 252  * @l: pointer of type local_t
 253  * @a: the amount to add to l...
 254  * @u: ...unless l is equal to u.
 255  *
 256  * Atomically adds @a to @l, so long as it was not @u.
 257  * Returns non-zero if @l was not @u, and zero otherwise.
 258  */
 259 static inline int local_add_unless(local_t *l, long a, long u)
 260 {
 261         long c, old;
 262         c = local_read(l);
 263         for (;;) {
 264                 if (unlikely(c == (u)))
 265                         break;
 266                 old = local_cmpxchg((l), c, c + (a));
 267                 if (likely(old == c))
 268                         break;
 269                 c = old;
 270         }
 271         return c != (u);
 272 }
 273
 274 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 275
 276 static inline void local_clear_mask(unsigned long  mask, local_t *addr)
 277 {
 278         unsigned long flags;
 279         unsigned long tmp;
 280
 281         local_irq_save(flags);
 282         __asm__ __volatile__ (
 283                 "# local_clear_mask             \n\t"
 284                 DCACHE_CLEAR("%0", "r5", "%1")
 285                 "ld %0, @%1;                    \n\t"
 286                 "and    %0, %2;                 \n\t"
 287                 "st %0, @%1;                    \n\t"
 288                 : "=&r" (tmp)
 289                 : "r" (addr), "r" (~mask)
 290                 : "memory"
 291 #ifdef CONFIG_CHIP_M32700_TS1
 292                 , "r5"
 293 #endif  /* CONFIG_CHIP_M32700_TS1 */
 294         );
 295         local_irq_restore(flags);
 296 }
 297
 298 static inline void local_set_mask(unsigned long  mask, local_t *addr)
 299 {
 300         unsigned long flags;
 301         unsigned long tmp;
 302
 303         local_irq_save(flags);
 304         __asm__ __volatile__ (
 305                 "# local_set_mask               \n\t"
 306                 DCACHE_CLEAR("%0", "r5", "%1")
 307                 "ld %0, @%1;                    \n\t"
 308                 "or     %0, %2;                 \n\t"
 309                 "st %0, @%1;                    \n\t"
 310                 : "=&r" (tmp)
 311                 : "r" (addr), "r" (mask)
 312                 : "memory"
 313 #ifdef CONFIG_CHIP_M32700_TS1
 314                 , "r5"
 315 #endif  /* CONFIG_CHIP_M32700_TS1 */
 316         );
 317         local_irq_restore(flags);
 318 }
 319
 320 /* Atomic operations are already serializing on m32r */
 321 #define smp_mb__before_local_dec()      barrier()
 322 #define smp_mb__after_local_dec()       barrier()
 323 #define smp_mb__before_local_inc()      barrier()
 324 #define smp_mb__after_local_inc()       barrier()
 325
 326 /* Use these for per-cpu local_t variables: on some archs they are
 327  * much more efficient than these naive implementations.  Note they take
 328  * a variable, not an address.
 329  */
 330
 331 #define __local_inc(l)          ((l)->a.counter++)
 332 #define __local_dec(l)          ((l)->a.counter++)
 333 #define __local_add(i, l)       ((l)->a.counter += (i))
 334 #define __local_sub(i, l)       ((l)->a.counter -= (i))
 335
 336 /* Use these for per-cpu local_t variables: on some archs they are
 337  * much more efficient than these naive implementations.  Note they take
 338  * a variable, not an address.
 339  */
 340
 341 /* Need to disable preemption for the cpu local counters otherwise we could
 342    still access a variable of a previous CPU in a non local way. */
 343 #define cpu_local_wrap_v(l)             \
 344         ({ local_t res__;               \
 345            preempt_disable();           \
 346            res__ = (l);                 \
 347            preempt_enable();            \
 348            res__; })
 349 #define cpu_local_wrap(l)               \
 350         ({ preempt_disable();           \
 351            l;                           \
 352            preempt_enable(); })         \
 353
 354 #define cpu_local_read(l)    cpu_local_wrap_v(local_read(&__get_cpu_var(l)))
 355 #define cpu_local_set(l, i)  cpu_local_wrap(local_set(&__get_cpu_var(l), (i)))
 356 #define cpu_local_inc(l)     cpu_local_wrap(local_inc(&__get_cpu_var(l)))
 357 #define cpu_local_dec(l)     cpu_local_wrap(local_dec(&__get_cpu_var(l)))
 358 #define cpu_local_add(i, l)  cpu_local_wrap(local_add((i), &__get_cpu_var(l)))
 359 #define cpu_local_sub(i, l)  cpu_local_wrap(local_sub((i), &__get_cpu_var(l)))
 360
 361 #define __cpu_local_inc(l)      cpu_local_inc(l)
 362 #define __cpu_local_dec(l)      cpu_local_dec(l)
 363 #define __cpu_local_add(i, l)   cpu_local_add((i), (l))
 364 #define __cpu_local_sub(i, l)   cpu_local_sub((i), (l))
 365
 366 #endif /* __M32R_LOCAL_H */