1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2019 Intel Corporation
3  */
4 
5 #ifndef _RTE_COMMON_H_
6 #define _RTE_COMMON_H_
7 
8 /**
9  * @file
10  *
11  * Generic, commonly-used macro and inline function definitions
12  * for DPDK.
13  */
14 
15 #ifdef __cplusplus
16 extern "C" {
17 #endif
18 
19 #include <stdint.h>
20 #include <stdlib.h>
21 #include <ctype.h>
22 #include <errno.h>
23 #include <limits.h>
24 
25 #include <rte_config.h>
26 
27 /* OS specific include */
28 #include <rte_os.h>
29 
30 #ifndef typeof
31 #define typeof __typeof__
32 #endif
33 
34 #ifndef asm
35 #define asm __asm__
36 #endif
37 
38 /** C extension macro for environments lacking C11 features. */
39 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
40 #define RTE_STD_C11 __extension__
41 #else
42 #define RTE_STD_C11
43 #endif
44 
45 /*
46  * RTE_TOOLCHAIN_GCC is defined if the target is built with GCC,
47  * while a host application (like pmdinfogen) may have another compiler.
48  * RTE_CC_IS_GNU is true if the file is compiled with GCC,
49  * no matter it is a target or host application.
50  */
51 #define RTE_CC_IS_GNU 0
52 #if defined __clang__
53 #define RTE_CC_CLANG
54 #elif defined __INTEL_COMPILER
55 #define RTE_CC_ICC
56 #elif defined __GNUC__
57 #define RTE_CC_GCC
58 #undef RTE_CC_IS_GNU
59 #define RTE_CC_IS_GNU 1
60 #endif
61 #if RTE_CC_IS_GNU
62 #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 +	\
63 		__GNUC_PATCHLEVEL__)
64 #endif
65 
66 /**
67  * Force alignment
68  */
69 #define __rte_aligned(a) __attribute__((__aligned__(a)))
70 
71 #ifdef RTE_ARCH_STRICT_ALIGN
72 typedef uint64_t unaligned_uint64_t __rte_aligned(1);
73 typedef uint32_t unaligned_uint32_t __rte_aligned(1);
74 typedef uint16_t unaligned_uint16_t __rte_aligned(1);
75 #else
76 typedef uint64_t unaligned_uint64_t;
77 typedef uint32_t unaligned_uint32_t;
78 typedef uint16_t unaligned_uint16_t;
79 #endif
80 
81 /**
82  * Force a structure to be packed
83  */
84 #define __rte_packed __attribute__((__packed__))
85 
86 /******* Macro to mark functions and fields scheduled for removal *****/
87 #define __rte_deprecated	__attribute__((__deprecated__))
88 #define __rte_deprecated_msg(msg)	__attribute__((__deprecated__(msg)))
89 
90 /**
91  *  Macro to mark macros and defines scheduled for removal
92  */
93 #if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
94 #define RTE_PRAGMA(x)  _Pragma(#x)
95 #define RTE_PRAGMA_WARNING(w) RTE_PRAGMA(GCC warning #w)
96 #define RTE_DEPRECATED(x)  RTE_PRAGMA_WARNING(#x is deprecated)
97 #else
98 #define RTE_DEPRECATED(x)
99 #endif
100 
101 /**
102  * Mark a function or variable to a weak reference.
103  */
104 #define __rte_weak __attribute__((__weak__))
105 
106 /**
107  * Force symbol to be generated even if it appears to be unused.
108  */
109 #define __rte_used __attribute__((used))
110 
111 /*********** Macros to eliminate unused variable warnings ********/
112 
113 /**
114  * short definition to mark a function parameter unused
115  */
116 #define __rte_unused __attribute__((__unused__))
117 
118 /**
119  * Mark pointer as restricted with regard to pointer aliasing.
120  */
121 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901L
122 #define __rte_restrict __restrict
123 #else
124 #define __rte_restrict restrict
125 #endif
126 
127 /**
128  * definition to mark a variable or function parameter as used so
129  * as to avoid a compiler warning
130  */
131 #define RTE_SET_USED(x) (void)(x)
132 
133 /**
134  * Check format string and its arguments at compile-time.
135  *
136  * GCC on Windows assumes MS-specific format string by default,
137  * even if the underlying stdio implementation is ANSI-compliant,
138  * so this must be overridden.
139  */
140 #if RTE_CC_IS_GNU
141 #define __rte_format_printf(format_index, first_arg) \
142 	__attribute__((format(gnu_printf, format_index, first_arg)))
143 #else
144 #define __rte_format_printf(format_index, first_arg) \
145 	__attribute__((format(printf, format_index, first_arg)))
146 #endif
147 
148 /**
149  * Tells compiler that the function returns a value that points to
150  * memory, where the size is given by the one or two arguments.
151  * Used by compiler to validate object size.
152  */
153 #if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
154 #define __rte_alloc_size(...) \
155 	__attribute__((alloc_size(__VA_ARGS__)))
156 #else
157 #define __rte_alloc_size(...)
158 #endif
159 
160 #define RTE_PRIORITY_LOG 101
161 #define RTE_PRIORITY_BUS 110
162 #define RTE_PRIORITY_CLASS 120
163 #define RTE_PRIORITY_LAST 65535
164 
165 #define RTE_PRIO(prio) \
166 	RTE_PRIORITY_ ## prio
167 
168 /**
169  * Run function before main() with high priority.
170  *
171  * @param func
172  *   Constructor function.
173  * @param prio
174  *   Priority number must be above 100.
175  *   Lowest number is the first to run.
176  */
177 #ifndef RTE_INIT_PRIO /* Allow to override from EAL */
178 #define RTE_INIT_PRIO(func, prio) \
179 static void __attribute__((constructor(RTE_PRIO(prio)), used)) func(void)
180 #endif
181 
182 /**
183  * Run function before main() with low priority.
184  *
185  * The constructor will be run after prioritized constructors.
186  *
187  * @param func
188  *   Constructor function.
189  */
190 #define RTE_INIT(func) \
191 	RTE_INIT_PRIO(func, LAST)
192 
193 /**
194  * Run after main() with low priority.
195  *
196  * @param func
197  *   Destructor function name.
198  * @param prio
199  *   Priority number must be above 100.
200  *   Lowest number is the last to run.
201  */
202 #ifndef RTE_FINI_PRIO /* Allow to override from EAL */
203 #define RTE_FINI_PRIO(func, prio) \
204 static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
205 #endif
206 
207 /**
208  * Run after main() with high priority.
209  *
210  * The destructor will be run *before* prioritized destructors.
211  *
212  * @param func
213  *   Destructor function name.
214  */
215 #define RTE_FINI(func) \
216 	RTE_FINI_PRIO(func, LAST)
217 
218 /**
219  * Hint never returning function
220  */
221 #define __rte_noreturn __attribute__((noreturn))
222 
223 /**
224  * Force a function to be inlined
225  */
226 #define __rte_always_inline inline __attribute__((always_inline))
227 
228 /**
229  * Force a function to be noinlined
230  */
231 #define __rte_noinline __attribute__((noinline))
232 
233 /**
234  * Hint function in the hot path
235  */
236 #define __rte_hot __attribute__((hot))
237 
238 /**
239  * Hint function in the cold path
240  */
241 #define __rte_cold __attribute__((cold))
242 
243 /*********** Macros for pointer arithmetic ********/
244 
245 /**
246  * add a byte-value offset to a pointer
247  */
248 #define RTE_PTR_ADD(ptr, x) ((void*)((uintptr_t)(ptr) + (x)))
249 
250 /**
251  * subtract a byte-value offset from a pointer
252  */
253 #define RTE_PTR_SUB(ptr, x) ((void*)((uintptr_t)ptr - (x)))
254 
255 /**
256  * get the difference between two pointer values, i.e. how far apart
257  * in bytes are the locations they point two. It is assumed that
258  * ptr1 is greater than ptr2.
259  */
260 #define RTE_PTR_DIFF(ptr1, ptr2) ((uintptr_t)(ptr1) - (uintptr_t)(ptr2))
261 
262 /**
263  * Workaround to cast a const field of a structure to non-const type.
264  */
265 #define RTE_CAST_FIELD(var, field, type) \
266 	(*(type *)((uintptr_t)(var) + offsetof(typeof(*(var)), field)))
267 
268 /*********** Macros/static functions for doing alignment ********/
269 
270 
271 /**
272  * Macro to align a pointer to a given power-of-two. The resultant
273  * pointer will be a pointer of the same type as the first parameter, and
274  * point to an address no higher than the first parameter. Second parameter
275  * must be a power-of-two value.
276  */
277 #define RTE_PTR_ALIGN_FLOOR(ptr, align) \
278 	((typeof(ptr))RTE_ALIGN_FLOOR((uintptr_t)ptr, align))
279 
280 /**
281  * Macro to align a value to a given power-of-two. The resultant value
282  * will be of the same type as the first parameter, and will be no
283  * bigger than the first parameter. Second parameter must be a
284  * power-of-two value.
285  */
286 #define RTE_ALIGN_FLOOR(val, align) \
287 	(typeof(val))((val) & (~((typeof(val))((align) - 1))))
288 
289 /**
290  * Macro to align a pointer to a given power-of-two. The resultant
291  * pointer will be a pointer of the same type as the first parameter, and
292  * point to an address no lower than the first parameter. Second parameter
293  * must be a power-of-two value.
294  */
295 #define RTE_PTR_ALIGN_CEIL(ptr, align) \
296 	RTE_PTR_ALIGN_FLOOR((typeof(ptr))RTE_PTR_ADD(ptr, (align) - 1), align)
297 
298 /**
299  * Macro to align a value to a given power-of-two. The resultant value
300  * will be of the same type as the first parameter, and will be no lower
301  * than the first parameter. Second parameter must be a power-of-two
302  * value.
303  */
304 #define RTE_ALIGN_CEIL(val, align) \
305 	RTE_ALIGN_FLOOR(((val) + ((typeof(val)) (align) - 1)), align)
306 
307 /**
308  * Macro to align a pointer to a given power-of-two. The resultant
309  * pointer will be a pointer of the same type as the first parameter, and
310  * point to an address no lower than the first parameter. Second parameter
311  * must be a power-of-two value.
312  * This function is the same as RTE_PTR_ALIGN_CEIL
313  */
314 #define RTE_PTR_ALIGN(ptr, align) RTE_PTR_ALIGN_CEIL(ptr, align)
315 
316 /**
317  * Macro to align a value to a given power-of-two. The resultant
318  * value will be of the same type as the first parameter, and
319  * will be no lower than the first parameter. Second parameter
320  * must be a power-of-two value.
321  * This function is the same as RTE_ALIGN_CEIL
322  */
323 #define RTE_ALIGN(val, align) RTE_ALIGN_CEIL(val, align)
324 
325 /**
326  * Macro to align a value to the multiple of given value. The resultant
327  * value will be of the same type as the first parameter and will be no lower
328  * than the first parameter.
329  */
330 #define RTE_ALIGN_MUL_CEIL(v, mul) \
331 	((((v) + (typeof(v))(mul) - 1) / ((typeof(v))(mul))) * (typeof(v))(mul))
332 
333 /**
334  * Macro to align a value to the multiple of given value. The resultant
335  * value will be of the same type as the first parameter and will be no higher
336  * than the first parameter.
337  */
338 #define RTE_ALIGN_MUL_FLOOR(v, mul) \
339 	(((v) / ((typeof(v))(mul))) * (typeof(v))(mul))
340 
341 /**
342  * Macro to align value to the nearest multiple of the given value.
343  * The resultant value might be greater than or less than the first parameter
344  * whichever difference is the lowest.
345  */
346 #define RTE_ALIGN_MUL_NEAR(v, mul)				\
347 	({							\
348 		typeof(v) ceil = RTE_ALIGN_MUL_CEIL(v, mul);	\
349 		typeof(v) floor = RTE_ALIGN_MUL_FLOOR(v, mul);	\
350 		(ceil - (v)) > ((v) - floor) ? floor : ceil;	\
351 	})
352 
353 /**
354  * Checks if a pointer is aligned to a given power-of-two value
355  *
356  * @param ptr
357  *   The pointer whose alignment is to be checked
358  * @param align
359  *   The power-of-two value to which the ptr should be aligned
360  *
361  * @return
362  *   True(1) where the pointer is correctly aligned, false(0) otherwise
363  */
364 static inline int
rte_is_aligned(void * ptr,unsigned align)365 rte_is_aligned(void *ptr, unsigned align)
366 {
367 	return RTE_PTR_ALIGN(ptr, align) == ptr;
368 }
369 
370 /*********** Macros for compile type checks ********/
371 
372 /**
373  * Triggers an error at compilation time if the condition is true.
374  */
375 #define RTE_BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
376 
377 /*********** Cache line related macros ********/
378 
379 /** Cache line mask. */
380 #define RTE_CACHE_LINE_MASK (RTE_CACHE_LINE_SIZE-1)
381 
382 /** Return the first cache-aligned value greater or equal to size. */
383 #define RTE_CACHE_LINE_ROUNDUP(size) \
384 	(RTE_CACHE_LINE_SIZE * ((size + RTE_CACHE_LINE_SIZE - 1) / \
385 	RTE_CACHE_LINE_SIZE))
386 
387 /** Cache line size in terms of log2 */
388 #if RTE_CACHE_LINE_SIZE == 64
389 #define RTE_CACHE_LINE_SIZE_LOG2 6
390 #elif RTE_CACHE_LINE_SIZE == 128
391 #define RTE_CACHE_LINE_SIZE_LOG2 7
392 #else
393 #error "Unsupported cache line size"
394 #endif
395 
396 /** Minimum Cache line size. */
397 #define RTE_CACHE_LINE_MIN_SIZE 64
398 
399 /** Force alignment to cache line. */
400 #define __rte_cache_aligned __rte_aligned(RTE_CACHE_LINE_SIZE)
401 
402 /** Force minimum cache line alignment. */
403 #define __rte_cache_min_aligned __rte_aligned(RTE_CACHE_LINE_MIN_SIZE)
404 
405 /*********** PA/IOVA type definitions ********/
406 
407 /** Physical address */
408 typedef uint64_t phys_addr_t;
409 #define RTE_BAD_PHYS_ADDR ((phys_addr_t)-1)
410 
411 /**
412  * IO virtual address type.
413  * When the physical addressing mode (IOVA as PA) is in use,
414  * the translation from an IO virtual address (IOVA) to a physical address
415  * is a direct mapping, i.e. the same value.
416  * Otherwise, in virtual mode (IOVA as VA), an IOMMU may do the translation.
417  */
418 typedef uint64_t rte_iova_t;
419 #define RTE_BAD_IOVA ((rte_iova_t)-1)
420 
421 /*********** Structure alignment markers ********/
422 
423 /** Generic marker for any place in a structure. */
424 __extension__ typedef void    *RTE_MARKER[0];
425 /** Marker for 1B alignment in a structure. */
426 __extension__ typedef uint8_t  RTE_MARKER8[0];
427 /** Marker for 2B alignment in a structure. */
428 __extension__ typedef uint16_t RTE_MARKER16[0];
429 /** Marker for 4B alignment in a structure. */
430 __extension__ typedef uint32_t RTE_MARKER32[0];
431 /** Marker for 8B alignment in a structure. */
432 __extension__ typedef uint64_t RTE_MARKER64[0];
433 
434 /**
435  * Combines 32b inputs most significant set bits into the least
436  * significant bits to construct a value with the same MSBs as x
437  * but all 1's under it.
438  *
439  * @param x
440  *    The integer whose MSBs need to be combined with its LSBs
441  * @return
442  *    The combined value.
443  */
444 static inline uint32_t
rte_combine32ms1b(uint32_t x)445 rte_combine32ms1b(uint32_t x)
446 {
447 	x |= x >> 1;
448 	x |= x >> 2;
449 	x |= x >> 4;
450 	x |= x >> 8;
451 	x |= x >> 16;
452 
453 	return x;
454 }
455 
456 /**
457  * Combines 64b inputs most significant set bits into the least
458  * significant bits to construct a value with the same MSBs as x
459  * but all 1's under it.
460  *
461  * @param v
462  *    The integer whose MSBs need to be combined with its LSBs
463  * @return
464  *    The combined value.
465  */
466 static inline uint64_t
rte_combine64ms1b(uint64_t v)467 rte_combine64ms1b(uint64_t v)
468 {
469 	v |= v >> 1;
470 	v |= v >> 2;
471 	v |= v >> 4;
472 	v |= v >> 8;
473 	v |= v >> 16;
474 	v |= v >> 32;
475 
476 	return v;
477 }
478 
479 /*********** Macros to work with powers of 2 ********/
480 
481 /**
482  * Macro to return 1 if n is a power of 2, 0 otherwise
483  */
484 #define RTE_IS_POWER_OF_2(n) ((n) && !(((n) - 1) & (n)))
485 
486 /**
487  * Returns true if n is a power of 2
488  * @param n
489  *     Number to check
490  * @return 1 if true, 0 otherwise
491  */
492 static inline int
rte_is_power_of_2(uint32_t n)493 rte_is_power_of_2(uint32_t n)
494 {
495 	return n && !(n & (n - 1));
496 }
497 
498 /**
499  * Aligns input parameter to the next power of 2
500  *
501  * @param x
502  *   The integer value to align
503  *
504  * @return
505  *   Input parameter aligned to the next power of 2
506  */
507 static inline uint32_t
rte_align32pow2(uint32_t x)508 rte_align32pow2(uint32_t x)
509 {
510 	x--;
511 	x = rte_combine32ms1b(x);
512 
513 	return x + 1;
514 }
515 
516 /**
517  * Aligns input parameter to the previous power of 2
518  *
519  * @param x
520  *   The integer value to align
521  *
522  * @return
523  *   Input parameter aligned to the previous power of 2
524  */
525 static inline uint32_t
rte_align32prevpow2(uint32_t x)526 rte_align32prevpow2(uint32_t x)
527 {
528 	x = rte_combine32ms1b(x);
529 
530 	return x - (x >> 1);
531 }
532 
533 /**
534  * Aligns 64b input parameter to the next power of 2
535  *
536  * @param v
537  *   The 64b value to align
538  *
539  * @return
540  *   Input parameter aligned to the next power of 2
541  */
542 static inline uint64_t
rte_align64pow2(uint64_t v)543 rte_align64pow2(uint64_t v)
544 {
545 	v--;
546 	v = rte_combine64ms1b(v);
547 
548 	return v + 1;
549 }
550 
551 /**
552  * Aligns 64b input parameter to the previous power of 2
553  *
554  * @param v
555  *   The 64b value to align
556  *
557  * @return
558  *   Input parameter aligned to the previous power of 2
559  */
560 static inline uint64_t
rte_align64prevpow2(uint64_t v)561 rte_align64prevpow2(uint64_t v)
562 {
563 	v = rte_combine64ms1b(v);
564 
565 	return v - (v >> 1);
566 }
567 
568 /*********** Macros for calculating min and max **********/
569 
570 /**
571  * Macro to return the minimum of two numbers
572  */
573 #define RTE_MIN(a, b) \
574 	__extension__ ({ \
575 		typeof (a) _a = (a); \
576 		typeof (b) _b = (b); \
577 		_a < _b ? _a : _b; \
578 	})
579 
580 /**
581  * Macro to return the maximum of two numbers
582  */
583 #define RTE_MAX(a, b) \
584 	__extension__ ({ \
585 		typeof (a) _a = (a); \
586 		typeof (b) _b = (b); \
587 		_a > _b ? _a : _b; \
588 	})
589 
590 /*********** Other general functions / macros ********/
591 
592 /**
593  * Searches the input parameter for the least significant set bit
594  * (starting from zero).
595  * If a least significant 1 bit is found, its bit index is returned.
596  * If the content of the input parameter is zero, then the content of the return
597  * value is undefined.
598  * @param v
599  *     input parameter, should not be zero.
600  * @return
601  *     least significant set bit in the input parameter.
602  */
603 static inline uint32_t
rte_bsf32(uint32_t v)604 rte_bsf32(uint32_t v)
605 {
606 	return (uint32_t)__builtin_ctz(v);
607 }
608 
609 /**
610  * Searches the input parameter for the least significant set bit
611  * (starting from zero). Safe version (checks for input parameter being zero).
612  *
613  * @warning ``pos`` must be a valid pointer. It is not checked!
614  *
615  * @param v
616  *     The input parameter.
617  * @param pos
618  *     If ``v`` was not 0, this value will contain position of least significant
619  *     bit within the input parameter.
620  * @return
621  *     Returns 0 if ``v`` was 0, otherwise returns 1.
622  */
623 static inline int
rte_bsf32_safe(uint64_t v,uint32_t * pos)624 rte_bsf32_safe(uint64_t v, uint32_t *pos)
625 {
626 	if (v == 0)
627 		return 0;
628 
629 	*pos = rte_bsf32(v);
630 	return 1;
631 }
632 
633 /**
634  * Return the rounded-up log2 of a integer.
635  *
636  * @note Contrary to the logarithm mathematical operation,
637  * rte_log2_u32(0) == 0 and not -inf.
638  *
639  * @param v
640  *     The input parameter.
641  * @return
642  *     The rounded-up log2 of the input, or 0 if the input is 0.
643  */
644 static inline uint32_t
rte_log2_u32(uint32_t v)645 rte_log2_u32(uint32_t v)
646 {
647 	if (v == 0)
648 		return 0;
649 	v = rte_align32pow2(v);
650 	return rte_bsf32(v);
651 }
652 
653 
654 /**
655  * Return the last (most-significant) bit set.
656  *
657  * @note The last (most significant) bit is at position 32.
658  * @note rte_fls_u32(0) = 0, rte_fls_u32(1) = 1, rte_fls_u32(0x80000000) = 32
659  *
660  * @param x
661  *     The input parameter.
662  * @return
663  *     The last (most-significant) bit set, or 0 if the input is 0.
664  */
665 static inline int
rte_fls_u32(uint32_t x)666 rte_fls_u32(uint32_t x)
667 {
668 	return (x == 0) ? 0 : 32 - __builtin_clz(x);
669 }
670 
671 /**
672  * Searches the input parameter for the least significant set bit
673  * (starting from zero).
674  * If a least significant 1 bit is found, its bit index is returned.
675  * If the content of the input parameter is zero, then the content of the return
676  * value is undefined.
677  * @param v
678  *     input parameter, should not be zero.
679  * @return
680  *     least significant set bit in the input parameter.
681  */
682 static inline int
rte_bsf64(uint64_t v)683 rte_bsf64(uint64_t v)
684 {
685 	return (uint32_t)__builtin_ctzll(v);
686 }
687 
688 /**
689  * Searches the input parameter for the least significant set bit
690  * (starting from zero). Safe version (checks for input parameter being zero).
691  *
692  * @warning ``pos`` must be a valid pointer. It is not checked!
693  *
694  * @param v
695  *     The input parameter.
696  * @param pos
697  *     If ``v`` was not 0, this value will contain position of least significant
698  *     bit within the input parameter.
699  * @return
700  *     Returns 0 if ``v`` was 0, otherwise returns 1.
701  */
702 static inline int
rte_bsf64_safe(uint64_t v,uint32_t * pos)703 rte_bsf64_safe(uint64_t v, uint32_t *pos)
704 {
705 	if (v == 0)
706 		return 0;
707 
708 	*pos = rte_bsf64(v);
709 	return 1;
710 }
711 
712 /**
713  * Return the last (most-significant) bit set.
714  *
715  * @note The last (most significant) bit is at position 64.
716  * @note rte_fls_u64(0) = 0, rte_fls_u64(1) = 1,
717  *       rte_fls_u64(0x8000000000000000) = 64
718  *
719  * @param x
720  *     The input parameter.
721  * @return
722  *     The last (most-significant) bit set, or 0 if the input is 0.
723  */
724 static inline int
rte_fls_u64(uint64_t x)725 rte_fls_u64(uint64_t x)
726 {
727 	return (x == 0) ? 0 : 64 - __builtin_clzll(x);
728 }
729 
730 /**
731  * Return the rounded-up log2 of a 64-bit integer.
732  *
733  * @note Contrary to the logarithm mathematical operation,
734  * rte_log2_u64(0) == 0 and not -inf.
735  *
736  * @param v
737  *     The input parameter.
738  * @return
739  *     The rounded-up log2 of the input, or 0 if the input is 0.
740  */
741 static inline uint32_t
rte_log2_u64(uint64_t v)742 rte_log2_u64(uint64_t v)
743 {
744 	if (v == 0)
745 		return 0;
746 	v = rte_align64pow2(v);
747 	/* we checked for v being 0 already, so no undefined behavior */
748 	return rte_bsf64(v);
749 }
750 
751 #ifndef offsetof
752 /** Return the offset of a field in a structure. */
753 #define offsetof(TYPE, MEMBER)  __builtin_offsetof (TYPE, MEMBER)
754 #endif
755 
756 /**
757  * Return pointer to the wrapping struct instance.
758  *
759  * Example:
760  *
761  *  struct wrapper {
762  *      ...
763  *      struct child c;
764  *      ...
765  *  };
766  *
767  *  struct child *x = obtain(...);
768  *  struct wrapper *w = container_of(x, struct wrapper, c);
769  */
770 #ifndef container_of
771 #define container_of(ptr, type, member)	__extension__ ({		\
772 			const typeof(((type *)0)->member) *_ptr = (ptr); \
773 			__rte_unused type *_target_ptr =	\
774 				(type *)(ptr);				\
775 			(type *)(((uintptr_t)_ptr) - offsetof(type, member)); \
776 		})
777 #endif
778 
779 /**
780  * Get the size of a field in a structure.
781  *
782  * @param type
783  *   The type of the structure.
784  * @param field
785  *   The field in the structure.
786  * @return
787  *   The size of the field in the structure, in bytes.
788  */
789 #define RTE_SIZEOF_FIELD(type, field) (sizeof(((type *)0)->field))
790 
791 #define _RTE_STR(x) #x
792 /** Take a macro value and get a string version of it */
793 #define RTE_STR(x) _RTE_STR(x)
794 
795 /**
796  * ISO C helpers to modify format strings using variadic macros.
797  * This is a replacement for the ", ## __VA_ARGS__" GNU extension.
798  * An empty %s argument is appended to avoid a dangling comma.
799  */
800 #define RTE_FMT(fmt, ...) fmt "%.0s", __VA_ARGS__ ""
801 #define RTE_FMT_HEAD(fmt, ...) fmt
802 #define RTE_FMT_TAIL(fmt, ...) __VA_ARGS__
803 
804 /** Mask value of type "tp" for the first "ln" bit set. */
805 #define	RTE_LEN2MASK(ln, tp)	\
806 	((tp)((uint64_t)-1 >> (sizeof(uint64_t) * CHAR_BIT - (ln))))
807 
808 /** Number of elements in the array. */
809 #define	RTE_DIM(a)	(sizeof (a) / sizeof ((a)[0]))
810 
811 /**
812  * Converts a numeric string to the equivalent uint64_t value.
813  * As well as straight number conversion, also recognises the suffixes
814  * k, m and g for kilobytes, megabytes and gigabytes respectively.
815  *
816  * If a negative number is passed in  i.e. a string with the first non-black
817  * character being "-", zero is returned. Zero is also returned in the case of
818  * an error with the strtoull call in the function.
819  *
820  * @param str
821  *     String containing number to convert.
822  * @return
823  *     Number.
824  */
825 static inline uint64_t
rte_str_to_size(const char * str)826 rte_str_to_size(const char *str)
827 {
828 	char *endptr;
829 	unsigned long long size;
830 
831 	while (isspace((int)*str))
832 		str++;
833 	if (*str == '-')
834 		return 0;
835 
836 	errno = 0;
837 	size = strtoull(str, &endptr, 0);
838 	if (errno)
839 		return 0;
840 
841 	if (*endptr == ' ')
842 		endptr++; /* allow 1 space gap */
843 
844 	switch (*endptr){
845 	case 'G': case 'g': size *= 1024; /* fall-through */
846 	case 'M': case 'm': size *= 1024; /* fall-through */
847 	case 'K': case 'k': size *= 1024; /* fall-through */
848 	default:
849 		break;
850 	}
851 	return size;
852 }
853 
854 /**
855  * Function to terminate the application immediately, printing an error
856  * message and returning the exit_code back to the shell.
857  *
858  * This function never returns
859  *
860  * @param exit_code
861  *     The exit code to be returned by the application
862  * @param format
863  *     The format string to be used for printing the message. This can include
864  *     printf format characters which will be expanded using any further parameters
865  *     to the function.
866  */
867 __rte_noreturn void
868 rte_exit(int exit_code, const char *format, ...)
869 	__rte_format_printf(2, 3);
870 
871 #ifdef __cplusplus
872 }
873 #endif
874 
875 #endif
876