qemu/include/qemu/bswap.h
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   1#ifndef BSWAP_H
   2#define BSWAP_H
   3
   4#ifdef CONFIG_MACHINE_BSWAP_H
   5# include <sys/endian.h>
   6# include <machine/bswap.h>
   7#elif defined(__FreeBSD__)
   8# include <sys/endian.h>
   9#elif defined(__HAIKU__)
  10# include <endian.h>
  11#elif defined(CONFIG_BYTESWAP_H)
  12# include <byteswap.h>
  13#define BSWAP_FROM_BYTESWAP
  14# else
  15#define BSWAP_FROM_FALLBACKS
  16#endif /* ! CONFIG_MACHINE_BSWAP_H */
  17
  18#ifdef __cplusplus
  19extern "C" {
  20#endif
  21
  22#ifdef BSWAP_FROM_BYTESWAP
  23static inline uint16_t bswap16(uint16_t x)
  24{
  25    return bswap_16(x);
  26}
  27
  28static inline uint32_t bswap32(uint32_t x)
  29{
  30    return bswap_32(x);
  31}
  32
  33static inline uint64_t bswap64(uint64_t x)
  34{
  35    return bswap_64(x);
  36}
  37#endif
  38
  39#ifdef BSWAP_FROM_FALLBACKS
  40static inline uint16_t bswap16(uint16_t x)
  41{
  42    return (((x & 0x00ff) << 8) |
  43            ((x & 0xff00) >> 8));
  44}
  45
  46static inline uint32_t bswap32(uint32_t x)
  47{
  48    return (((x & 0x000000ffU) << 24) |
  49            ((x & 0x0000ff00U) <<  8) |
  50            ((x & 0x00ff0000U) >>  8) |
  51            ((x & 0xff000000U) >> 24));
  52}
  53
  54static inline uint64_t bswap64(uint64_t x)
  55{
  56    return (((x & 0x00000000000000ffULL) << 56) |
  57            ((x & 0x000000000000ff00ULL) << 40) |
  58            ((x & 0x0000000000ff0000ULL) << 24) |
  59            ((x & 0x00000000ff000000ULL) <<  8) |
  60            ((x & 0x000000ff00000000ULL) >>  8) |
  61            ((x & 0x0000ff0000000000ULL) >> 24) |
  62            ((x & 0x00ff000000000000ULL) >> 40) |
  63            ((x & 0xff00000000000000ULL) >> 56));
  64}
  65#endif
  66
  67#undef BSWAP_FROM_BYTESWAP
  68#undef BSWAP_FROM_FALLBACKS
  69
  70static inline void bswap16s(uint16_t *s)
  71{
  72    *s = bswap16(*s);
  73}
  74
  75static inline void bswap32s(uint32_t *s)
  76{
  77    *s = bswap32(*s);
  78}
  79
  80static inline void bswap64s(uint64_t *s)
  81{
  82    *s = bswap64(*s);
  83}
  84
  85#if HOST_BIG_ENDIAN
  86#define be_bswap(v, size) (v)
  87#define le_bswap(v, size) glue(bswap, size)(v)
  88#define be_bswaps(v, size)
  89#define le_bswaps(p, size) do { *p = glue(bswap, size)(*p); } while(0)
  90#else
  91#define le_bswap(v, size) (v)
  92#define be_bswap(v, size) glue(bswap, size)(v)
  93#define le_bswaps(v, size)
  94#define be_bswaps(p, size) do { *p = glue(bswap, size)(*p); } while(0)
  95#endif
  96
  97/**
  98 * Endianness conversion functions between host cpu and specified endianness.
  99 * (We list the complete set of prototypes produced by the macros below
 100 * to assist people who search the headers to find their definitions.)
 101 *
 102 * uint16_t le16_to_cpu(uint16_t v);
 103 * uint32_t le32_to_cpu(uint32_t v);
 104 * uint64_t le64_to_cpu(uint64_t v);
 105 * uint16_t be16_to_cpu(uint16_t v);
 106 * uint32_t be32_to_cpu(uint32_t v);
 107 * uint64_t be64_to_cpu(uint64_t v);
 108 *
 109 * Convert the value @v from the specified format to the native
 110 * endianness of the host CPU by byteswapping if necessary, and
 111 * return the converted value.
 112 *
 113 * uint16_t cpu_to_le16(uint16_t v);
 114 * uint32_t cpu_to_le32(uint32_t v);
 115 * uint64_t cpu_to_le64(uint64_t v);
 116 * uint16_t cpu_to_be16(uint16_t v);
 117 * uint32_t cpu_to_be32(uint32_t v);
 118 * uint64_t cpu_to_be64(uint64_t v);
 119 *
 120 * Convert the value @v from the native endianness of the host CPU to
 121 * the specified format by byteswapping if necessary, and return
 122 * the converted value.
 123 *
 124 * void le16_to_cpus(uint16_t *v);
 125 * void le32_to_cpus(uint32_t *v);
 126 * void le64_to_cpus(uint64_t *v);
 127 * void be16_to_cpus(uint16_t *v);
 128 * void be32_to_cpus(uint32_t *v);
 129 * void be64_to_cpus(uint64_t *v);
 130 *
 131 * Do an in-place conversion of the value pointed to by @v from the
 132 * specified format to the native endianness of the host CPU.
 133 *
 134 * void cpu_to_le16s(uint16_t *v);
 135 * void cpu_to_le32s(uint32_t *v);
 136 * void cpu_to_le64s(uint64_t *v);
 137 * void cpu_to_be16s(uint16_t *v);
 138 * void cpu_to_be32s(uint32_t *v);
 139 * void cpu_to_be64s(uint64_t *v);
 140 *
 141 * Do an in-place conversion of the value pointed to by @v from the
 142 * native endianness of the host CPU to the specified format.
 143 *
 144 * Both X_to_cpu() and cpu_to_X() perform the same operation; you
 145 * should use whichever one is better documenting of the function your
 146 * code is performing.
 147 *
 148 * Do not use these functions for conversion of values which are in guest
 149 * memory, since the data may not be sufficiently aligned for the host CPU's
 150 * load and store instructions. Instead you should use the ld*_p() and
 151 * st*_p() functions, which perform loads and stores of data of any
 152 * required size and endianness and handle possible misalignment.
 153 */
 154
 155#define CPU_CONVERT(endian, size, type)\
 156static inline type endian ## size ## _to_cpu(type v)\
 157{\
 158    return glue(endian, _bswap)(v, size);\
 159}\
 160\
 161static inline type cpu_to_ ## endian ## size(type v)\
 162{\
 163    return glue(endian, _bswap)(v, size);\
 164}\
 165\
 166static inline void endian ## size ## _to_cpus(type *p)\
 167{\
 168    glue(endian, _bswaps)(p, size);\
 169}\
 170\
 171static inline void cpu_to_ ## endian ## size ## s(type *p)\
 172{\
 173    glue(endian, _bswaps)(p, size);\
 174}
 175
 176CPU_CONVERT(be, 16, uint16_t)
 177CPU_CONVERT(be, 32, uint32_t)
 178CPU_CONVERT(be, 64, uint64_t)
 179
 180CPU_CONVERT(le, 16, uint16_t)
 181CPU_CONVERT(le, 32, uint32_t)
 182CPU_CONVERT(le, 64, uint64_t)
 183
 184/*
 185 * Same as cpu_to_le{16,32}, except that gcc will figure the result is
 186 * a compile-time constant if you pass in a constant.  So this can be
 187 * used to initialize static variables.
 188 */
 189#if HOST_BIG_ENDIAN
 190# define const_le32(_x)                          \
 191    ((((_x) & 0x000000ffU) << 24) |              \
 192     (((_x) & 0x0000ff00U) <<  8) |              \
 193     (((_x) & 0x00ff0000U) >>  8) |              \
 194     (((_x) & 0xff000000U) >> 24))
 195# define const_le16(_x)                          \
 196    ((((_x) & 0x00ff) << 8) |                    \
 197     (((_x) & 0xff00) >> 8))
 198#else
 199# define const_le32(_x) (_x)
 200# define const_le16(_x) (_x)
 201#endif
 202
 203/* unaligned/endian-independent pointer access */
 204
 205/*
 206 * the generic syntax is:
 207 *
 208 * load: ld{type}{sign}{size}_{endian}_p(ptr)
 209 *
 210 * store: st{type}{size}_{endian}_p(ptr, val)
 211 *
 212 * Note there are small differences with the softmmu access API!
 213 *
 214 * type is:
 215 * (empty): integer access
 216 *   f    : float access
 217 *
 218 * sign is:
 219 * (empty): for 32 or 64 bit sizes (including floats and doubles)
 220 *   u    : unsigned
 221 *   s    : signed
 222 *
 223 * size is:
 224 *   b: 8 bits
 225 *   w: 16 bits
 226 *   l: 32 bits
 227 *   q: 64 bits
 228 *
 229 * endian is:
 230 *   he   : host endian
 231 *   be   : big endian
 232 *   le   : little endian
 233 *   te   : target endian
 234 * (except for byte accesses, which have no endian infix).
 235 *
 236 * The target endian accessors are obviously only available to source
 237 * files which are built per-target; they are defined in cpu-all.h.
 238 *
 239 * In all cases these functions take a host pointer.
 240 * For accessors that take a guest address rather than a
 241 * host address, see the cpu_{ld,st}_* accessors defined in
 242 * cpu_ldst.h.
 243 *
 244 * For cases where the size to be used is not fixed at compile time,
 245 * there are
 246 *  stn_{endian}_p(ptr, sz, val)
 247 * which stores @val to @ptr as an @endian-order number @sz bytes in size
 248 * and
 249 *  ldn_{endian}_p(ptr, sz)
 250 * which loads @sz bytes from @ptr as an unsigned @endian-order number
 251 * and returns it in a uint64_t.
 252 */
 253
 254static inline int ldub_p(const void *ptr)
 255{
 256    return *(uint8_t *)ptr;
 257}
 258
 259static inline int ldsb_p(const void *ptr)
 260{
 261    return *(int8_t *)ptr;
 262}
 263
 264static inline void stb_p(void *ptr, uint8_t v)
 265{
 266    *(uint8_t *)ptr = v;
 267}
 268
 269/*
 270 * Any compiler worth its salt will turn these memcpy into native unaligned
 271 * operations.  Thus we don't need to play games with packed attributes, or
 272 * inline byte-by-byte stores.
 273 * Some compilation environments (eg some fortify-source implementations)
 274 * may intercept memcpy() in a way that defeats the compiler optimization,
 275 * though, so we use __builtin_memcpy() to give ourselves the best chance
 276 * of good performance.
 277 */
 278
 279static inline int lduw_he_p(const void *ptr)
 280{
 281    uint16_t r;
 282    __builtin_memcpy(&r, ptr, sizeof(r));
 283    return r;
 284}
 285
 286static inline int ldsw_he_p(const void *ptr)
 287{
 288    int16_t r;
 289    __builtin_memcpy(&r, ptr, sizeof(r));
 290    return r;
 291}
 292
 293static inline void stw_he_p(void *ptr, uint16_t v)
 294{
 295    __builtin_memcpy(ptr, &v, sizeof(v));
 296}
 297
 298static inline int ldl_he_p(const void *ptr)
 299{
 300    int32_t r;
 301    __builtin_memcpy(&r, ptr, sizeof(r));
 302    return r;
 303}
 304
 305static inline void stl_he_p(void *ptr, uint32_t v)
 306{
 307    __builtin_memcpy(ptr, &v, sizeof(v));
 308}
 309
 310static inline uint64_t ldq_he_p(const void *ptr)
 311{
 312    uint64_t r;
 313    __builtin_memcpy(&r, ptr, sizeof(r));
 314    return r;
 315}
 316
 317static inline void stq_he_p(void *ptr, uint64_t v)
 318{
 319    __builtin_memcpy(ptr, &v, sizeof(v));
 320}
 321
 322static inline int lduw_le_p(const void *ptr)
 323{
 324    return (uint16_t)le_bswap(lduw_he_p(ptr), 16);
 325}
 326
 327static inline int ldsw_le_p(const void *ptr)
 328{
 329    return (int16_t)le_bswap(lduw_he_p(ptr), 16);
 330}
 331
 332static inline int ldl_le_p(const void *ptr)
 333{
 334    return le_bswap(ldl_he_p(ptr), 32);
 335}
 336
 337static inline uint64_t ldq_le_p(const void *ptr)
 338{
 339    return le_bswap(ldq_he_p(ptr), 64);
 340}
 341
 342static inline void stw_le_p(void *ptr, uint16_t v)
 343{
 344    stw_he_p(ptr, le_bswap(v, 16));
 345}
 346
 347static inline void stl_le_p(void *ptr, uint32_t v)
 348{
 349    stl_he_p(ptr, le_bswap(v, 32));
 350}
 351
 352static inline void stq_le_p(void *ptr, uint64_t v)
 353{
 354    stq_he_p(ptr, le_bswap(v, 64));
 355}
 356
 357static inline int lduw_be_p(const void *ptr)
 358{
 359    return (uint16_t)be_bswap(lduw_he_p(ptr), 16);
 360}
 361
 362static inline int ldsw_be_p(const void *ptr)
 363{
 364    return (int16_t)be_bswap(lduw_he_p(ptr), 16);
 365}
 366
 367static inline int ldl_be_p(const void *ptr)
 368{
 369    return be_bswap(ldl_he_p(ptr), 32);
 370}
 371
 372static inline uint64_t ldq_be_p(const void *ptr)
 373{
 374    return be_bswap(ldq_he_p(ptr), 64);
 375}
 376
 377static inline void stw_be_p(void *ptr, uint16_t v)
 378{
 379    stw_he_p(ptr, be_bswap(v, 16));
 380}
 381
 382static inline void stl_be_p(void *ptr, uint32_t v)
 383{
 384    stl_he_p(ptr, be_bswap(v, 32));
 385}
 386
 387static inline void stq_be_p(void *ptr, uint64_t v)
 388{
 389    stq_he_p(ptr, be_bswap(v, 64));
 390}
 391
 392static inline unsigned long leul_to_cpu(unsigned long v)
 393{
 394#if HOST_LONG_BITS == 32
 395    return le_bswap(v, 32);
 396#elif HOST_LONG_BITS == 64
 397    return le_bswap(v, 64);
 398#else
 399# error Unknown sizeof long
 400#endif
 401}
 402
 403/* Store v to p as a sz byte value in host order */
 404#define DO_STN_LDN_P(END) \
 405    static inline void stn_## END ## _p(void *ptr, int sz, uint64_t v)  \
 406    {                                                                   \
 407        switch (sz) {                                                   \
 408        case 1:                                                         \
 409            stb_p(ptr, v);                                              \
 410            break;                                                      \
 411        case 2:                                                         \
 412            stw_ ## END ## _p(ptr, v);                                  \
 413            break;                                                      \
 414        case 4:                                                         \
 415            stl_ ## END ## _p(ptr, v);                                  \
 416            break;                                                      \
 417        case 8:                                                         \
 418            stq_ ## END ## _p(ptr, v);                                  \
 419            break;                                                      \
 420        default:                                                        \
 421            g_assert_not_reached();                                     \
 422        }                                                               \
 423    }                                                                   \
 424    static inline uint64_t ldn_## END ## _p(const void *ptr, int sz)    \
 425    {                                                                   \
 426        switch (sz) {                                                   \
 427        case 1:                                                         \
 428            return ldub_p(ptr);                                         \
 429        case 2:                                                         \
 430            return lduw_ ## END ## _p(ptr);                             \
 431        case 4:                                                         \
 432            return (uint32_t)ldl_ ## END ## _p(ptr);                    \
 433        case 8:                                                         \
 434            return ldq_ ## END ## _p(ptr);                              \
 435        default:                                                        \
 436            g_assert_not_reached();                                     \
 437        }                                                               \
 438    }
 439
 440DO_STN_LDN_P(he)
 441DO_STN_LDN_P(le)
 442DO_STN_LDN_P(be)
 443
 444#undef DO_STN_LDN_P
 445
 446#undef le_bswap
 447#undef be_bswap
 448#undef le_bswaps
 449#undef be_bswaps
 450
 451#ifdef __cplusplus
 452}
 453#endif
 454
 455#endif /* BSWAP_H */
 456