ceph/src/dpdk/lib/librte_eal/common/include/rte_common.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #ifndef _RTE_COMMON_H_
  35 #define _RTE_COMMON_H_
  36
  37 /**
  38  * @file
  39  *
  40  * Generic, commonly-used macro and inline function definitions
  41  * for DPDK.
  42  */
  43
  44 #ifdef __cplusplus
  45 extern "C" {
  46 #endif
  47
  48 #include <stdint.h>
  49 #include <stdlib.h>
  50 #include <ctype.h>
  51 #include <errno.h>
  52 #include <limits.h>
  53
  54 #ifndef typeof
  55 #define typeof __typeof__
  56 #endif
  57
  58 #ifndef asm
  59 #define asm __asm__
  60 #endif
  61
  62 /** C extension macro for environments lacking C11 features. */
  63 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
  64 #define RTE_STD_C11 __extension__
  65 #else
  66 #define RTE_STD_C11
  67 #endif
  68
  69 #ifdef RTE_ARCH_STRICT_ALIGN
  70 typedef uint64_t unaligned_uint64_t __attribute__ ((aligned(1)));
  71 typedef uint32_t unaligned_uint32_t __attribute__ ((aligned(1)));
  72 typedef uint16_t unaligned_uint16_t __attribute__ ((aligned(1)));
  73 #else
  74 typedef uint64_t unaligned_uint64_t;
  75 typedef uint32_t unaligned_uint32_t;
  76 typedef uint16_t unaligned_uint16_t;
  77 #endif
  78
  79 /**
  80  * Force alignment
  81  */
  82 #define __rte_aligned(a) __attribute__((__aligned__(a)))
  83
  84 /**
  85  * Force a structure to be packed
  86  */
  87 #define __rte_packed __attribute__((__packed__))
  88
  89 /******* Macro to mark functions and fields scheduled for removal *****/
  90 #define __rte_deprecated        __attribute__((__deprecated__))
  91
  92 /*********** Macros to eliminate unused variable warnings ********/
  93
  94 /**
  95  * short definition to mark a function parameter unused
  96  */
  97 #define __rte_unused __attribute__((__unused__))
  98
  99 /**
 100  * definition to mark a variable or function parameter as used so
 101  * as to avoid a compiler warning
 102  */
 103 #define RTE_SET_USED(x) (void)(x)
 104
 105 /*********** Macros for pointer arithmetic ********/
 106
 107 /**
 108  * add a byte-value offset from a pointer
 109  */
 110 #define RTE_PTR_ADD(ptr, x) ((void*)((uintptr_t)(ptr) + (x)))
 111
 112 /**
 113  * subtract a byte-value offset from a pointer
 114  */
 115 #define RTE_PTR_SUB(ptr, x) ((void*)((uintptr_t)ptr - (x)))
 116
 117 /**
 118  * get the difference between two pointer values, i.e. how far apart
 119  * in bytes are the locations they point two. It is assumed that
 120  * ptr1 is greater than ptr2.
 121  */
 122 #define RTE_PTR_DIFF(ptr1, ptr2) ((uintptr_t)(ptr1) - (uintptr_t)(ptr2))
 123
 124 /*********** Macros/static functions for doing alignment ********/
 125
 126
 127 /**
 128  * Macro to align a pointer to a given power-of-two. The resultant
 129  * pointer will be a pointer of the same type as the first parameter, and
 130  * point to an address no higher than the first parameter. Second parameter
 131  * must be a power-of-two value.
 132  */
 133 #define RTE_PTR_ALIGN_FLOOR(ptr, align) \
 134         ((typeof(ptr))RTE_ALIGN_FLOOR((uintptr_t)ptr, align))
 135
 136 /**
 137  * Macro to align a value to a given power-of-two. The resultant value
 138  * will be of the same type as the first parameter, and will be no
 139  * bigger than the first parameter. Second parameter must be a
 140  * power-of-two value.
 141  */
 142 #define RTE_ALIGN_FLOOR(val, align) \
 143         (typeof(val))((val) & (~((typeof(val))((align) - 1))))
 144
 145 /**
 146  * Macro to align a pointer to a given power-of-two. The resultant
 147  * pointer will be a pointer of the same type as the first parameter, and
 148  * point to an address no lower than the first parameter. Second parameter
 149  * must be a power-of-two value.
 150  */
 151 #define RTE_PTR_ALIGN_CEIL(ptr, align) \
 152         RTE_PTR_ALIGN_FLOOR((typeof(ptr))RTE_PTR_ADD(ptr, (align) - 1), align)
 153
 154 /**
 155  * Macro to align a value to a given power-of-two. The resultant value
 156  * will be of the same type as the first parameter, and will be no lower
 157  * than the first parameter. Second parameter must be a power-of-two
 158  * value.
 159  */
 160 #define RTE_ALIGN_CEIL(val, align) \
 161         RTE_ALIGN_FLOOR(((val) + ((typeof(val)) (align) - 1)), align)
 162
 163 /**
 164  * Macro to align a pointer to a given power-of-two. The resultant
 165  * pointer will be a pointer of the same type as the first parameter, and
 166  * point to an address no lower than the first parameter. Second parameter
 167  * must be a power-of-two value.
 168  * This function is the same as RTE_PTR_ALIGN_CEIL
 169  */
 170 #define RTE_PTR_ALIGN(ptr, align) RTE_PTR_ALIGN_CEIL(ptr, align)
 171
 172 /**
 173  * Macro to align a value to a given power-of-two. The resultant
 174  * value will be of the same type as the first parameter, and
 175  * will be no lower than the first parameter. Second parameter
 176  * must be a power-of-two value.
 177  * This function is the same as RTE_ALIGN_CEIL
 178  */
 179 #define RTE_ALIGN(val, align) RTE_ALIGN_CEIL(val, align)
 180
 181 /**
 182  * Checks if a pointer is aligned to a given power-of-two value
 183  *
 184  * @param ptr
 185  *   The pointer whose alignment is to be checked
 186  * @param align
 187  *   The power-of-two value to which the ptr should be aligned
 188  *
 189  * @return
 190  *   True(1) where the pointer is correctly aligned, false(0) otherwise
 191  */
 192 static inline int
 193 rte_is_aligned(void *ptr, unsigned align)
 194 {
 195         return RTE_PTR_ALIGN(ptr, align) == ptr;
 196 }
 197
 198 /*********** Macros for compile type checks ********/
 199
 200 /**
 201  * Triggers an error at compilation time if the condition is true.
 202  */
 203 #ifndef __OPTIMIZE__
 204 #define RTE_BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 205 #else
 206 extern int RTE_BUILD_BUG_ON_detected_error;
 207 #define RTE_BUILD_BUG_ON(condition) do {             \
 208         ((void)sizeof(char[1 - 2*!!(condition)]));   \
 209         if (condition)                               \
 210                 RTE_BUILD_BUG_ON_detected_error = 1; \
 211 } while(0)
 212 #endif
 213
 214 /*********** Macros to work with powers of 2 ********/
 215
 216 /**
 217  * Returns true if n is a power of 2
 218  * @param n
 219  *     Number to check
 220  * @return 1 if true, 0 otherwise
 221  */
 222 static inline int
 223 rte_is_power_of_2(uint32_t n)
 224 {
 225         return n && !(n & (n - 1));
 226 }
 227
 228 /**
 229  * Aligns input parameter to the next power of 2
 230  *
 231  * @param x
 232  *   The integer value to algin
 233  *
 234  * @return
 235  *   Input parameter aligned to the next power of 2
 236  */
 237 static inline uint32_t
 238 rte_align32pow2(uint32_t x)
 239 {
 240         x--;
 241         x |= x >> 1;
 242         x |= x >> 2;
 243         x |= x >> 4;
 244         x |= x >> 8;
 245         x |= x >> 16;
 246
 247         return x + 1;
 248 }
 249
 250 /**
 251  * Aligns 64b input parameter to the next power of 2
 252  *
 253  * @param v
 254  *   The 64b value to align
 255  *
 256  * @return
 257  *   Input parameter aligned to the next power of 2
 258  */
 259 static inline uint64_t
 260 rte_align64pow2(uint64_t v)
 261 {
 262         v--;
 263         v |= v >> 1;
 264         v |= v >> 2;
 265         v |= v >> 4;
 266         v |= v >> 8;
 267         v |= v >> 16;
 268         v |= v >> 32;
 269
 270         return v + 1;
 271 }
 272
 273 /*********** Macros for calculating min and max **********/
 274
 275 /**
 276  * Macro to return the minimum of two numbers
 277  */
 278 #define RTE_MIN(a, b) \
 279         __extension__ ({ \
 280                 typeof (a) _a = (a); \
 281                 typeof (b) _b = (b); \
 282                 _a < _b ? _a : _b; \
 283         })
 284
 285 /**
 286  * Macro to return the maximum of two numbers
 287  */
 288 #define RTE_MAX(a, b) \
 289         __extension__ ({ \
 290                 typeof (a) _a = (a); \
 291                 typeof (b) _b = (b); \
 292                 _a > _b ? _a : _b; \
 293         })
 294
 295 /*********** Other general functions / macros ********/
 296
 297 #ifdef __SSE2__
 298 #include <emmintrin.h>
 299 /**
 300  * PAUSE instruction for tight loops (avoid busy waiting)
 301  */
 302 static inline void
 303 rte_pause (void)
 304 {
 305         _mm_pause();
 306 }
 307 #else
 308 static inline void
 309 rte_pause(void) {}
 310 #endif
 311
 312 /**
 313  * Searches the input parameter for the least significant set bit
 314  * (starting from zero).
 315  * If a least significant 1 bit is found, its bit index is returned.
 316  * If the content of the input parameter is zero, then the content of the return
 317  * value is undefined.
 318  * @param v
 319  *     input parameter, should not be zero.
 320  * @return
 321  *     least significant set bit in the input parameter.
 322  */
 323 static inline uint32_t
 324 rte_bsf32(uint32_t v)
 325 {
 326         return __builtin_ctz(v);
 327 }
 328
 329 #ifndef offsetof
 330 /** Return the offset of a field in a structure. */
 331 #define offsetof(TYPE, MEMBER)  __builtin_offsetof (TYPE, MEMBER)
 332 #endif
 333
 334 #define _RTE_STR(x) #x
 335 /** Take a macro value and get a string version of it */
 336 #define RTE_STR(x) _RTE_STR(x)
 337
 338 /**
 339  * ISO C helpers to modify format strings using variadic macros.
 340  * This is a replacement for the ", ## __VA_ARGS__" GNU extension.
 341  * An empty %s argument is appended to avoid a dangling comma.
 342  */
 343 #define RTE_FMT(fmt, ...) fmt "%.0s", __VA_ARGS__ ""
 344 #define RTE_FMT_HEAD(fmt, ...) fmt
 345 #define RTE_FMT_TAIL(fmt, ...) __VA_ARGS__
 346
 347 /** Mask value of type "tp" for the first "ln" bit set. */
 348 #define RTE_LEN2MASK(ln, tp)    \
 349         ((tp)((uint64_t)-1 >> (sizeof(uint64_t) * CHAR_BIT - (ln))))
 350
 351 /** Number of elements in the array. */
 352 #define RTE_DIM(a)      (sizeof (a) / sizeof ((a)[0]))
 353
 354 /**
 355  * Converts a numeric string to the equivalent uint64_t value.
 356  * As well as straight number conversion, also recognises the suffixes
 357  * k, m and g for kilobytes, megabytes and gigabytes respectively.
 358  *
 359  * If a negative number is passed in  i.e. a string with the first non-black
 360  * character being "-", zero is returned. Zero is also returned in the case of
 361  * an error with the strtoull call in the function.
 362  *
 363  * @param str
 364  *     String containing number to convert.
 365  * @return
 366  *     Number.
 367  */
 368 static inline uint64_t
 369 rte_str_to_size(const char *str)
 370 {
 371         char *endptr;
 372         unsigned long long size;
 373
 374         while (isspace((int)*str))
 375                 str++;
 376         if (*str == '-')
 377                 return 0;
 378
 379         errno = 0;
 380         size = strtoull(str, &endptr, 0);
 381         if (errno)
 382                 return 0;
 383
 384         if (*endptr == ' ')
 385                 endptr++; /* allow 1 space gap */
 386
 387         switch (*endptr){
 388         case 'G': case 'g': size *= 1024; /* fall-through */
 389         case 'M': case 'm': size *= 1024; /* fall-through */
 390         case 'K': case 'k': size *= 1024; /* fall-through */
 391         default:
 392                 break;
 393         }
 394         return size;
 395 }
 396
 397 /**
 398  * Function to terminate the application immediately, printing an error
 399  * message and returning the exit_code back to the shell.
 400  *
 401  * This function never returns
 402  *
 403  * @param exit_code
 404  *     The exit code to be returned by the application
 405  * @param format
 406  *     The format string to be used for printing the message. This can include
 407  *     printf format characters which will be expanded using any further parameters
 408  *     to the function.
 409  */
 410 void
 411 rte_exit(int exit_code, const char *format, ...)
 412         __attribute__((noreturn))
 413         __attribute__((format(printf, 2, 3)));
 414
 415 #ifdef __cplusplus
 416 }
 417 #endif
 418
 419 #endif