linux/include/asm-frv/atomic.h
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   1/* atomic.h: atomic operation emulation for FR-V
   2 *
   3 * For an explanation of how atomic ops work in this arch, see:
   4 *   Documentation/fujitsu/frv/atomic-ops.txt
   5 *
   6 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   7 * Written by David Howells (dhowells@redhat.com)
   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
  11 * as published by the Free Software Foundation; either version
  12 * 2 of the License, or (at your option) any later version.
  13 */
  14#ifndef _ASM_ATOMIC_H
  15#define _ASM_ATOMIC_H
  16
  17#include <linux/types.h>
  18#include <asm/spr-regs.h>
  19
  20#ifdef CONFIG_SMP
  21#error not SMP safe
  22#endif
  23
  24/*
  25 * Atomic operations that C can't guarantee us.  Useful for
  26 * resource counting etc..
  27 *
  28 * We do not have SMP systems, so we don't have to deal with that.
  29 */
  30
  31/* Atomic operations are already serializing */
  32#define smp_mb__before_atomic_dec()     barrier()
  33#define smp_mb__after_atomic_dec()      barrier()
  34#define smp_mb__before_atomic_inc()     barrier()
  35#define smp_mb__after_atomic_inc()      barrier()
  36
  37typedef struct {
  38        int counter;
  39} atomic_t;
  40
  41#define ATOMIC_INIT(i)          { (i) }
  42#define atomic_read(v)          ((v)->counter)
  43#define atomic_set(v, i)        (((v)->counter) = (i))
  44
  45#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
  46static inline int atomic_add_return(int i, atomic_t *v)
  47{
  48        unsigned long val;
  49
  50        asm("0:                                         \n"
  51            "   orcc            gr0,gr0,gr0,icc3        \n"     /* set ICC3.Z */
  52            "   ckeq            icc3,cc7                \n"
  53            "   ld.p            %M0,%1                  \n"     /* LD.P/ORCR must be atomic */
  54            "   orcr            cc7,cc7,cc3             \n"     /* set CC3 to true */
  55            "   add%I2          %1,%2,%1                \n"
  56            "   cst.p           %1,%M0          ,cc3,#1 \n"
  57            "   corcc           gr29,gr29,gr0   ,cc3,#1 \n"     /* clear ICC3.Z if store happens */
  58            "   beq             icc3,#0,0b              \n"
  59            : "+U"(v->counter), "=&r"(val)
  60            : "NPr"(i)
  61            : "memory", "cc7", "cc3", "icc3"
  62            );
  63
  64        return val;
  65}
  66
  67static inline int atomic_sub_return(int i, atomic_t *v)
  68{
  69        unsigned long val;
  70
  71        asm("0:                                         \n"
  72            "   orcc            gr0,gr0,gr0,icc3        \n"     /* set ICC3.Z */
  73            "   ckeq            icc3,cc7                \n"
  74            "   ld.p            %M0,%1                  \n"     /* LD.P/ORCR must be atomic */
  75            "   orcr            cc7,cc7,cc3             \n"     /* set CC3 to true */
  76            "   sub%I2          %1,%2,%1                \n"
  77            "   cst.p           %1,%M0          ,cc3,#1 \n"
  78            "   corcc           gr29,gr29,gr0   ,cc3,#1 \n"     /* clear ICC3.Z if store happens */
  79            "   beq             icc3,#0,0b              \n"
  80            : "+U"(v->counter), "=&r"(val)
  81            : "NPr"(i)
  82            : "memory", "cc7", "cc3", "icc3"
  83            );
  84
  85        return val;
  86}
  87
  88#else
  89
  90extern int atomic_add_return(int i, atomic_t *v);
  91extern int atomic_sub_return(int i, atomic_t *v);
  92
  93#endif
  94
  95static inline int atomic_add_negative(int i, atomic_t *v)
  96{
  97        return atomic_add_return(i, v) < 0;
  98}
  99
 100static inline void atomic_add(int i, atomic_t *v)
 101{
 102        atomic_add_return(i, v);
 103}
 104
 105static inline void atomic_sub(int i, atomic_t *v)
 106{
 107        atomic_sub_return(i, v);
 108}
 109
 110static inline void atomic_inc(atomic_t *v)
 111{
 112        atomic_add_return(1, v);
 113}
 114
 115static inline void atomic_dec(atomic_t *v)
 116{
 117        atomic_sub_return(1, v);
 118}
 119
 120#define atomic_dec_return(v)            atomic_sub_return(1, (v))
 121#define atomic_inc_return(v)            atomic_add_return(1, (v))
 122
 123#define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
 124#define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
 125#define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
 126
 127#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
 128static inline
 129unsigned long atomic_test_and_ANDNOT_mask(unsigned long mask, volatile unsigned long *v)
 130{
 131        unsigned long old, tmp;
 132
 133        asm volatile(
 134                "0:                                             \n"
 135                "       orcc            gr0,gr0,gr0,icc3        \n"     /* set ICC3.Z */
 136                "       ckeq            icc3,cc7                \n"
 137                "       ld.p            %M0,%1                  \n"     /* LD.P/ORCR are atomic */
 138                "       orcr            cc7,cc7,cc3             \n"     /* set CC3 to true */
 139                "       and%I3          %1,%3,%2                \n"
 140                "       cst.p           %2,%M0          ,cc3,#1 \n"     /* if store happens... */
 141                "       corcc           gr29,gr29,gr0   ,cc3,#1 \n"     /* ... clear ICC3.Z */
 142                "       beq             icc3,#0,0b              \n"
 143                : "+U"(*v), "=&r"(old), "=r"(tmp)
 144                : "NPr"(~mask)
 145                : "memory", "cc7", "cc3", "icc3"
 146                );
 147
 148        return old;
 149}
 150
 151static inline
 152unsigned long atomic_test_and_OR_mask(unsigned long mask, volatile unsigned long *v)
 153{
 154        unsigned long old, tmp;
 155
 156        asm volatile(
 157                "0:                                             \n"
 158                "       orcc            gr0,gr0,gr0,icc3        \n"     /* set ICC3.Z */
 159                "       ckeq            icc3,cc7                \n"
 160                "       ld.p            %M0,%1                  \n"     /* LD.P/ORCR are atomic */
 161                "       orcr            cc7,cc7,cc3             \n"     /* set CC3 to true */
 162                "       or%I3           %1,%3,%2                \n"
 163                "       cst.p           %2,%M0          ,cc3,#1 \n"     /* if store happens... */
 164                "       corcc           gr29,gr29,gr0   ,cc3,#1 \n"     /* ... clear ICC3.Z */
 165                "       beq             icc3,#0,0b              \n"
 166                : "+U"(*v), "=&r"(old), "=r"(tmp)
 167                : "NPr"(mask)
 168                : "memory", "cc7", "cc3", "icc3"
 169                );
 170
 171        return old;
 172}
 173
 174static inline
 175unsigned long atomic_test_and_XOR_mask(unsigned long mask, volatile unsigned long *v)
 176{
 177        unsigned long old, tmp;
 178
 179        asm volatile(
 180                "0:                                             \n"
 181                "       orcc            gr0,gr0,gr0,icc3        \n"     /* set ICC3.Z */
 182                "       ckeq            icc3,cc7                \n"
 183                "       ld.p            %M0,%1                  \n"     /* LD.P/ORCR are atomic */
 184                "       orcr            cc7,cc7,cc3             \n"     /* set CC3 to true */
 185                "       xor%I3          %1,%3,%2                \n"
 186                "       cst.p           %2,%M0          ,cc3,#1 \n"     /* if store happens... */
 187                "       corcc           gr29,gr29,gr0   ,cc3,#1 \n"     /* ... clear ICC3.Z */
 188                "       beq             icc3,#0,0b              \n"
 189                : "+U"(*v), "=&r"(old), "=r"(tmp)
 190                : "NPr"(mask)
 191                : "memory", "cc7", "cc3", "icc3"
 192                );
 193
 194        return old;
 195}
 196
 197#else
 198
 199extern unsigned long atomic_test_and_ANDNOT_mask(unsigned long mask, volatile unsigned long *v);
 200extern unsigned long atomic_test_and_OR_mask(unsigned long mask, volatile unsigned long *v);
 201extern unsigned long atomic_test_and_XOR_mask(unsigned long mask, volatile unsigned long *v);
 202
 203#endif
 204
 205#define atomic_clear_mask(mask, v)      atomic_test_and_ANDNOT_mask((mask), (v))
 206#define atomic_set_mask(mask, v)        atomic_test_and_OR_mask((mask), (v))
 207
 208/*****************************************************************************/
 209/*
 210 * exchange value with memory
 211 */
 212#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
 213
 214#define xchg(ptr, x)                                                            \
 215({                                                                              \
 216        __typeof__(ptr) __xg_ptr = (ptr);                                       \
 217        __typeof__(*(ptr)) __xg_orig;                                           \
 218                                                                                \
 219        switch (sizeof(__xg_orig)) {                                            \
 220        case 4:                                                                 \
 221                asm volatile(                                                   \
 222                        "swap%I0 %M0,%1"                                        \
 223                        : "+m"(*__xg_ptr), "=r"(__xg_orig)                      \
 224                        : "1"(x)                                                \
 225                        : "memory"                                              \
 226                        );                                                      \
 227                break;                                                          \
 228                                                                                \
 229        default:                                                                \
 230                __xg_orig = (__typeof__(__xg_orig))0;                           \
 231                asm volatile("break");                                          \
 232                break;                                                          \
 233        }                                                                       \
 234                                                                                \
 235        __xg_orig;                                                              \
 236})
 237
 238#else
 239
 240extern uint32_t __xchg_32(uint32_t i, volatile void *v);
 241
 242#define xchg(ptr, x)                                                                            \
 243({                                                                                              \
 244        __typeof__(ptr) __xg_ptr = (ptr);                                                       \
 245        __typeof__(*(ptr)) __xg_orig;                                                           \
 246                                                                                                \
 247        switch (sizeof(__xg_orig)) {                                                            \
 248        case 4: __xg_orig = (__typeof__(*(ptr))) __xchg_32((uint32_t) x, __xg_ptr);     break;  \
 249        default:                                                                                \
 250                __xg_orig = (__typeof__(__xg_orig))0;                                                                   \
 251                asm volatile("break");                                                          \
 252                break;                                                                          \
 253        }                                                                                       \
 254        __xg_orig;                                                                              \
 255})
 256
 257#endif
 258
 259#define tas(ptr) (xchg((ptr), 1))
 260
 261/*****************************************************************************/
 262/*
 263 * compare and conditionally exchange value with memory
 264 * - if (*ptr == test) then orig = *ptr; *ptr = test;
 265 * - if (*ptr != test) then orig = *ptr;
 266 */
 267#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
 268
 269#define cmpxchg(ptr, test, new)                                                 \
 270({                                                                              \
 271        __typeof__(ptr) __xg_ptr = (ptr);                                       \
 272        __typeof__(*(ptr)) __xg_orig, __xg_tmp;                                 \
 273        __typeof__(*(ptr)) __xg_test = (test);                                  \
 274        __typeof__(*(ptr)) __xg_new = (new);                                    \
 275                                                                                \
 276        switch (sizeof(__xg_orig)) {                                            \
 277        case 4:                                                                 \
 278                asm volatile(                                                   \
 279                        "0:                                             \n"     \
 280                        "       orcc            gr0,gr0,gr0,icc3        \n"     \
 281                        "       ckeq            icc3,cc7                \n"     \
 282                        "       ld.p            %M0,%1                  \n"     \
 283                        "       orcr            cc7,cc7,cc3             \n"     \
 284                        "       sub%I4cc        %1,%4,%2,icc0           \n"     \
 285                        "       bne             icc0,#0,1f              \n"     \
 286                        "       cst.p           %3,%M0          ,cc3,#1 \n"     \
 287                        "       corcc           gr29,gr29,gr0   ,cc3,#1 \n"     \
 288                        "       beq             icc3,#0,0b              \n"     \
 289                        "1:                                             \n"     \
 290                        : "+U"(*__xg_ptr), "=&r"(__xg_orig), "=&r"(__xg_tmp)    \
 291                        : "r"(__xg_new), "NPr"(__xg_test)                       \
 292                        : "memory", "cc7", "cc3", "icc3", "icc0"                \
 293                        );                                                      \
 294                break;                                                          \
 295                                                                                \
 296        default:                                                                \
 297                __xg_orig = 0;                                                  \
 298                asm volatile("break");                                          \
 299                break;                                                          \
 300        }                                                                       \
 301                                                                                \
 302        __xg_orig;                                                              \
 303})
 304
 305#else
 306
 307extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new);
 308
 309#define cmpxchg(ptr, test, new)                                                 \
 310({                                                                              \
 311        __typeof__(ptr) __xg_ptr = (ptr);                                       \
 312        __typeof__(*(ptr)) __xg_orig;                                           \
 313        __typeof__(*(ptr)) __xg_test = (test);                                  \
 314        __typeof__(*(ptr)) __xg_new = (new);                                    \
 315                                                                                \
 316        switch (sizeof(__xg_orig)) {                                            \
 317        case 4: __xg_orig = __cmpxchg_32(__xg_ptr, __xg_test, __xg_new); break; \
 318        default:                                                                \
 319                __xg_orig = 0;                                                  \
 320                asm volatile("break");                                          \
 321                break;                                                          \
 322        }                                                                       \
 323                                                                                \
 324        __xg_orig;                                                              \
 325})
 326
 327#endif
 328
 329#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 330#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 331
 332#define atomic_add_unless(v, a, u)                              \
 333({                                                              \
 334        int c, old;                                             \
 335        c = atomic_read(v);                                     \
 336        while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
 337                c = old;                                        \
 338        c != (u);                                               \
 339})
 340
 341#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 342
 343#include <asm-generic/atomic.h>
 344#endif /* _ASM_ATOMIC_H */
 345
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