xref: /dpdk/lib/eal/include/rte_common.h (revision 37dda90ee15b7098bc48356868a87d34f727eecc)
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 #include <assert.h>
16 #include <limits.h>
17 #include <stdint.h>
18 #include <stdalign.h>
19 
20 #include <rte_config.h>
21 
22 /* OS specific include */
23 #include <rte_os.h>
24 
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28 
29 #ifndef RTE_TOOLCHAIN_MSVC
30 #ifndef typeof
31 #define typeof __typeof__
32 #endif
33 #endif
34 
35 #ifndef __cplusplus
36 #ifndef asm
37 #define asm __asm__
38 #endif
39 #endif
40 
41 #ifdef RTE_TOOLCHAIN_MSVC
42 #ifdef __cplusplus
43 #define __extension__
44 #endif
45 #endif
46 
47 #ifdef RTE_TOOLCHAIN_MSVC
48 #define __rte_constant(e) 0
49 #else
50 #define __rte_constant(e) __extension__(__builtin_constant_p(e))
51 #endif
52 
53 /*
54  * RTE_TOOLCHAIN_GCC is defined if the target is built with GCC,
55  * while a host application (like pmdinfogen) may have another compiler.
56  * RTE_CC_IS_GNU is true if the file is compiled with GCC,
57  * no matter it is a target or host application.
58  */
59 #define RTE_CC_IS_GNU 0
60 #if defined __clang__
61 #define RTE_CC_CLANG
62 #elif defined __INTEL_COMPILER
63 #define RTE_CC_ICC
64 #elif defined __GNUC__
65 #define RTE_CC_GCC
66 #undef RTE_CC_IS_GNU
67 #define RTE_CC_IS_GNU 1
68 #endif
69 #if RTE_CC_IS_GNU
70 #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 +	\
71 		__GNUC_PATCHLEVEL__)
72 #endif
73 
74 /**
75  * Force type alignment
76  *
77  * This macro should be used when alignment of a struct or union type
78  * is required. For toolchain compatibility it should appear between
79  * the {struct,union} keyword and tag. e.g.
80  *
81  *   struct __rte_aligned(8) tag { ... };
82  *
83  * If alignment of an object/variable is required then this macro should
84  * not be used, instead prefer C11 alignas(a).
85  */
86 #ifdef RTE_TOOLCHAIN_MSVC
87 #define __rte_aligned(a) __declspec(align(a))
88 #else
89 #define __rte_aligned(a) __attribute__((__aligned__(a)))
90 #endif
91 
92 #ifdef RTE_ARCH_STRICT_ALIGN
93 typedef uint64_t unaligned_uint64_t __rte_aligned(1);
94 typedef uint32_t unaligned_uint32_t __rte_aligned(1);
95 typedef uint16_t unaligned_uint16_t __rte_aligned(1);
96 #else
97 typedef uint64_t unaligned_uint64_t;
98 typedef uint32_t unaligned_uint32_t;
99 typedef uint16_t unaligned_uint16_t;
100 #endif
101 
102 /**
103  * Force a structure to be packed
104  */
105 #ifdef RTE_TOOLCHAIN_MSVC
106 #define __rte_packed
107 #else
108 #define __rte_packed __attribute__((__packed__))
109 #endif
110 
111 /**
112  * Macro to mark a type that is not subject to type-based aliasing rules
113  */
114 #ifdef RTE_TOOLCHAIN_MSVC
115 #define __rte_may_alias
116 #else
117 #define __rte_may_alias __attribute__((__may_alias__))
118 #endif
119 
120 /******* Macro to mark functions and fields scheduled for removal *****/
121 #ifdef RTE_TOOLCHAIN_MSVC
122 #define __rte_deprecated
123 #define __rte_deprecated_msg(msg)
124 #else
125 #define __rte_deprecated	__attribute__((__deprecated__))
126 #define __rte_deprecated_msg(msg)	__attribute__((__deprecated__(msg)))
127 #endif
128 
129 /**
130  *  Macro to mark macros and defines scheduled for removal
131  */
132 #if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
133 #define RTE_PRAGMA(x)  _Pragma(#x)
134 #define RTE_PRAGMA_WARNING(w) RTE_PRAGMA(GCC warning #w)
135 #define RTE_DEPRECATED(x)  RTE_PRAGMA_WARNING(#x is deprecated)
136 #else
137 #define RTE_DEPRECATED(x)
138 #endif
139 
140 /**
141  * Mark a function or variable to a weak reference.
142  */
143 #define __rte_weak __attribute__((__weak__))
144 
145 /**
146  * Mark a function to be pure.
147  */
148 #ifdef RTE_TOOLCHAIN_MSVC
149 #define __rte_pure
150 #else
151 #define __rte_pure __attribute__((pure))
152 #endif
153 
154 /**
155  * Force symbol to be generated even if it appears to be unused.
156  */
157 #ifdef RTE_TOOLCHAIN_MSVC
158 #define __rte_used
159 #else
160 #define __rte_used __attribute__((used))
161 #endif
162 
163 /*********** Macros to eliminate unused variable warnings ********/
164 
165 /**
166  * short definition to mark a function parameter unused
167  */
168 #ifdef RTE_TOOLCHAIN_MSVC
169 #define __rte_unused
170 #else
171 #define __rte_unused __attribute__((__unused__))
172 #endif
173 
174 /**
175  * Mark pointer as restricted with regard to pointer aliasing.
176  */
177 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901L
178 #define __rte_restrict __restrict
179 #else
180 #define __rte_restrict restrict
181 #endif
182 
183 /**
184  * definition to mark a variable or function parameter as used so
185  * as to avoid a compiler warning
186  */
187 #define RTE_SET_USED(x) (void)(x)
188 
189 /**
190  * Check format string and its arguments at compile-time.
191  *
192  * GCC on Windows assumes MS-specific format string by default,
193  * even if the underlying stdio implementation is ANSI-compliant,
194  * so this must be overridden.
195  */
196 #ifdef RTE_TOOLCHAIN_MSVC
197 #define __rte_format_printf(format_index, first_arg)
198 #else
199 #if RTE_CC_IS_GNU
200 #define __rte_format_printf(format_index, first_arg) \
201 	__attribute__((format(gnu_printf, format_index, first_arg)))
202 #else
203 #define __rte_format_printf(format_index, first_arg) \
204 	__attribute__((format(printf, format_index, first_arg)))
205 #endif
206 #endif
207 
208 /**
209  * Specify data or function section/segment.
210  */
211 #ifdef RTE_TOOLCHAIN_MSVC
212 #define __rte_section(name) \
213 	__pragma(data_seg(name)) __declspec(allocate(name))
214 #else
215 #define __rte_section(name) \
216 	__attribute__((section(name)))
217 #endif
218 
219 /**
220  * Tells compiler that the function returns a value that points to
221  * memory, where the size is given by the one or two arguments.
222  * Used by compiler to validate object size.
223  */
224 #if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
225 #define __rte_alloc_size(...) \
226 	__attribute__((alloc_size(__VA_ARGS__)))
227 #else
228 #define __rte_alloc_size(...)
229 #endif
230 
231 /**
232  * Tells the compiler that the function returns a value that points to
233  * memory aligned by a function argument.
234  *
235  * Note: not enabled on Clang because it warns if align argument is zero.
236  */
237 #if defined(RTE_CC_GCC)
238 #define __rte_alloc_align(argno) \
239 	__attribute__((alloc_align(argno)))
240 #else
241 #define __rte_alloc_align(argno)
242 #endif
243 
244 /**
245  * Tells the compiler this is a function like malloc and that the pointer
246  * returned cannot alias any other pointer (ie new memory).
247  */
248 #if defined(RTE_CC_GCC) || defined(RTE_CC_CLANG)
249 #define __rte_malloc __attribute__((__malloc__))
250 #else
251 #define __rte_malloc
252 #endif
253 
254 /**
255  * With recent GCC versions also able to track that proper
256  * deallocator function is used for this pointer.
257  */
258 #if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 110000)
259 #define __rte_dealloc(dealloc, argno) \
260 	__attribute__((malloc(dealloc, argno)))
261 #else
262 #define __rte_dealloc(dealloc, argno)
263 #endif
264 
265 #define RTE_PRIORITY_LOG 101
266 #define RTE_PRIORITY_BUS 110
267 #define RTE_PRIORITY_CLASS 120
268 #define RTE_PRIORITY_LAST 65535
269 
270 #define RTE_PRIO(prio) \
271 	RTE_PRIORITY_ ## prio
272 
273 /**
274  * Run function before main() with high priority.
275  *
276  * @param func
277  *   Constructor function.
278  * @param prio
279  *   Priority number must be above 100.
280  *   Lowest number is the first to run.
281  */
282 #ifndef RTE_INIT_PRIO /* Allow to override from EAL */
283 #ifndef RTE_TOOLCHAIN_MSVC
284 #define RTE_INIT_PRIO(func, prio) \
285 static void __attribute__((constructor(RTE_PRIO(prio)), used)) func(void)
286 #else
287 /* definition from the Microsoft CRT */
288 typedef int(__cdecl *_PIFV)(void);
289 
290 #define CTOR_SECTION_LOG ".CRT$XIB"
291 #define CTOR_SECTION_BUS ".CRT$XIC"
292 #define CTOR_SECTION_CLASS ".CRT$XID"
293 #define CTOR_SECTION_LAST ".CRT$XIY"
294 
295 #define CTOR_PRIORITY_TO_SECTION(priority) CTOR_SECTION_ ## priority
296 
297 #define RTE_INIT_PRIO(name, priority) \
298 	static void name(void); \
299 	static int __cdecl name ## _thunk(void) { name(); return 0; } \
300 	__pragma(const_seg(CTOR_PRIORITY_TO_SECTION(priority))) \
301 	__declspec(allocate(CTOR_PRIORITY_TO_SECTION(priority))) \
302 	    _PIFV name ## _pointer = &name ## _thunk; \
303 	__pragma(const_seg()) \
304 	static void name(void)
305 #endif
306 #endif
307 
308 /**
309  * Run function before main() with low priority.
310  *
311  * The constructor will be run after prioritized constructors.
312  *
313  * @param func
314  *   Constructor function.
315  */
316 #define RTE_INIT(func) \
317 	RTE_INIT_PRIO(func, LAST)
318 
319 /**
320  * Run after main() with low priority.
321  *
322  * @param func
323  *   Destructor function name.
324  * @param prio
325  *   Priority number must be above 100.
326  *   Lowest number is the last to run.
327  */
328 #ifndef RTE_FINI_PRIO /* Allow to override from EAL */
329 #ifndef RTE_TOOLCHAIN_MSVC
330 #define RTE_FINI_PRIO(func, prio) \
331 static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
332 #else
333 #define DTOR_SECTION_LOG "mydtor$B"
334 #define DTOR_SECTION_BUS "mydtor$C"
335 #define DTOR_SECTION_CLASS "mydtor$D"
336 #define DTOR_SECTION_LAST "mydtor$Y"
337 
338 #define DTOR_PRIORITY_TO_SECTION(priority) DTOR_SECTION_ ## priority
339 
340 #define RTE_FINI_PRIO(name, priority) \
341 	static void name(void); \
342 	__pragma(const_seg(DTOR_PRIORITY_TO_SECTION(priority))) \
343 	__declspec(allocate(DTOR_PRIORITY_TO_SECTION(priority))) void *name ## _pointer = &name; \
344 	__pragma(const_seg()) \
345 	static void name(void)
346 #endif
347 #endif
348 
349 /**
350  * Run after main() with high priority.
351  *
352  * The destructor will be run *before* prioritized destructors.
353  *
354  * @param func
355  *   Destructor function name.
356  */
357 #define RTE_FINI(func) \
358 	RTE_FINI_PRIO(func, LAST)
359 
360 /**
361  * Hint never returning function
362  */
363 #ifdef RTE_TOOLCHAIN_MSVC
364 #define __rte_noreturn
365 #else
366 #define __rte_noreturn __attribute__((noreturn))
367 #endif
368 
369 /**
370  * Hint point in program never reached
371  */
372 #if defined(RTE_TOOLCHAIN_GCC) || defined(RTE_TOOLCHAIN_CLANG)
373 #define __rte_unreachable() __extension__(__builtin_unreachable())
374 #else
375 #define __rte_unreachable() __assume(0)
376 #endif
377 
378 /**
379  * Issue a warning in case the function's return value is ignored.
380  *
381  * The use of this attribute should be restricted to cases where
382  * ignoring the marked function's return value is almost always a
383  * bug. With GCC, some effort is required to make clear that ignoring
384  * the return value is intentional. The usual void-casting method to
385  * mark something unused as used does not suppress the warning with
386  * this compiler.
387  *
388  * @code{.c}
389  * __rte_warn_unused_result int foo();
390  *
391  * void ignore_foo_result(void) {
392  *         foo(); // generates a warning with all compilers
393  *
394  *         (void)foo(); // still generates the warning with GCC (but not clang)
395  *
396  *         int unused __rte_unused;
397  *         unused = foo(); // does the trick with all compilers
398  *  }
399  * @endcode
400  */
401 #ifdef RTE_TOOLCHAIN_MSVC
402 #define __rte_warn_unused_result
403 #else
404 #define __rte_warn_unused_result __attribute__((warn_unused_result))
405 #endif
406 
407 /**
408  * Force a function to be inlined
409  */
410 #ifdef RTE_TOOLCHAIN_MSVC
411 #define __rte_always_inline
412 #else
413 #define __rte_always_inline inline __attribute__((always_inline))
414 #endif
415 
416 /**
417  * Force a function to be noinlined
418  */
419 #define __rte_noinline __attribute__((noinline))
420 
421 /**
422  * Hint function in the hot path
423  */
424 #define __rte_hot __attribute__((hot))
425 
426 /**
427  * Hint function in the cold path
428  */
429 #ifdef RTE_TOOLCHAIN_MSVC
430 #define __rte_cold
431 #else
432 #define __rte_cold __attribute__((cold))
433 #endif
434 
435 /**
436  * Hint precondition
437  *
438  * @warning Depending on the compiler, any code in ``condition`` might be executed.
439  * This currently only occurs with GCC prior to version 13.
440  */
441 #if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 130000)
442 #define __rte_assume(condition) __attribute__((assume(condition)))
443 #elif defined(RTE_TOOLCHAIN_GCC)
444 #define __rte_assume(condition) do { if (!(condition)) __rte_unreachable(); } while (0)
445 #elif defined(RTE_TOOLCHAIN_CLANG)
446 #define __rte_assume(condition) __extension__(__builtin_assume(condition))
447 #else
448 #define __rte_assume(condition) __assume(condition)
449 #endif
450 
451 /**
452  * Disable AddressSanitizer on some code
453  */
454 #ifdef RTE_MALLOC_ASAN
455 #ifdef RTE_CC_CLANG
456 #define __rte_no_asan __attribute__((no_sanitize("address", "hwaddress")))
457 #else
458 #define __rte_no_asan __attribute__((no_sanitize_address))
459 #endif
460 #else /* ! RTE_MALLOC_ASAN */
461 #define __rte_no_asan
462 #endif
463 
464 /*********** Macros for pointer arithmetic ********/
465 
466 /**
467  * add a byte-value offset to a pointer
468  */
469 #define RTE_PTR_ADD(ptr, x) ((void*)((uintptr_t)(ptr) + (x)))
470 
471 /**
472  * subtract a byte-value offset from a pointer
473  */
474 #define RTE_PTR_SUB(ptr, x) ((void *)((uintptr_t)(ptr) - (x)))
475 
476 /**
477  * get the difference between two pointer values, i.e. how far apart
478  * in bytes are the locations they point two. It is assumed that
479  * ptr1 is greater than ptr2.
480  */
481 #define RTE_PTR_DIFF(ptr1, ptr2) ((uintptr_t)(ptr1) - (uintptr_t)(ptr2))
482 
483 /**
484  * Workaround to cast a const field of a structure to non-const type.
485  */
486 #define RTE_CAST_FIELD(var, field, type) \
487 	(*(type *)((uintptr_t)(var) + offsetof(typeof(*(var)), field)))
488 
489 /*********** Macros/static functions for doing alignment ********/
490 
491 
492 /**
493  * Macro to align a pointer to a given power-of-two. The resultant
494  * pointer will be a pointer of the same type as the first parameter, and
495  * point to an address no higher than the first parameter. Second parameter
496  * must be a power-of-two value.
497  */
498 #define RTE_PTR_ALIGN_FLOOR(ptr, align) \
499 	((typeof(ptr))RTE_ALIGN_FLOOR((uintptr_t)(ptr), align))
500 
501 /**
502  * Macro to align a value to a given power-of-two. The resultant value
503  * will be of the same type as the first parameter, and will be no
504  * bigger than the first parameter. Second parameter must be a
505  * power-of-two value.
506  */
507 #define RTE_ALIGN_FLOOR(val, align) \
508 	(typeof(val))((val) & (~((typeof(val))((align) - 1))))
509 
510 /**
511  * Macro to align a pointer to a given power-of-two. The resultant
512  * pointer will be a pointer of the same type as the first parameter, and
513  * point to an address no lower than the first parameter. Second parameter
514  * must be a power-of-two value.
515  */
516 #define RTE_PTR_ALIGN_CEIL(ptr, align) \
517 	RTE_PTR_ALIGN_FLOOR((typeof(ptr))RTE_PTR_ADD(ptr, (align) - 1), align)
518 
519 /**
520  * Macro to align a value to a given power-of-two. The resultant value
521  * will be of the same type as the first parameter, and will be no lower
522  * than the first parameter. Second parameter must be a power-of-two
523  * value.
524  */
525 #define RTE_ALIGN_CEIL(val, align) \
526 	RTE_ALIGN_FLOOR(((val) + ((typeof(val)) (align) - 1)), align)
527 
528 /**
529  * Macro to align a pointer to a given power-of-two. The resultant
530  * pointer will be a pointer of the same type as the first parameter, and
531  * point to an address no lower than the first parameter. Second parameter
532  * must be a power-of-two value.
533  * This function is the same as RTE_PTR_ALIGN_CEIL
534  */
535 #define RTE_PTR_ALIGN(ptr, align) RTE_PTR_ALIGN_CEIL(ptr, align)
536 
537 /**
538  * Macro to align a value to a given power-of-two. The resultant
539  * value will be of the same type as the first parameter, and
540  * will be no lower than the first parameter. Second parameter
541  * must be a power-of-two value.
542  * This function is the same as RTE_ALIGN_CEIL
543  */
544 #define RTE_ALIGN(val, align) RTE_ALIGN_CEIL(val, align)
545 
546 /**
547  * Macro to align a value to the multiple of given value. The resultant
548  * value will be of the same type as the first parameter and will be no lower
549  * than the first parameter.
550  */
551 #define RTE_ALIGN_MUL_CEIL(v, mul) \
552 	((((v) + (typeof(v))(mul) - 1) / ((typeof(v))(mul))) * (typeof(v))(mul))
553 
554 /**
555  * Macro to align a value to the multiple of given value. The resultant
556  * value will be of the same type as the first parameter and will be no higher
557  * than the first parameter.
558  */
559 #define RTE_ALIGN_MUL_FLOOR(v, mul) \
560 	(((v) / ((typeof(v))(mul))) * (typeof(v))(mul))
561 
562 /**
563  * Macro to align value to the nearest multiple of the given value.
564  * The resultant value might be greater than or less than the first parameter
565  * whichever difference is the lowest.
566  */
567 #define RTE_ALIGN_MUL_NEAR(v, mul)				\
568 	__extension__ ({					\
569 		typeof(v) ceil = RTE_ALIGN_MUL_CEIL(v, mul);	\
570 		typeof(v) floor = RTE_ALIGN_MUL_FLOOR(v, mul);	\
571 		(ceil - (v)) > ((v) - floor) ? floor : ceil;	\
572 	})
573 
574 /**
575  * Checks if a pointer is aligned to a given power-of-two value
576  *
577  * @param ptr
578  *   The pointer whose alignment is to be checked
579  * @param align
580  *   The power-of-two value to which the ptr should be aligned
581  *
582  * @return
583  *   True(1) where the pointer is correctly aligned, false(0) otherwise
584  */
585 static inline int
586 rte_is_aligned(const void * const __rte_restrict ptr, const unsigned int align)
587 {
588 	return ((uintptr_t)ptr & (align - 1)) == 0;
589 }
590 
591 /*********** Macros for compile type checks ********/
592 
593 /* Workaround for toolchain issues with missing C11 macro in FreeBSD */
594 #if !defined(static_assert) && !defined(__cplusplus)
595 #define	static_assert	_Static_assert
596 #endif
597 
598 /**
599  * Triggers an error at compilation time if the condition is true.
600  *
601  * The do { } while(0) exists to workaround a bug in clang (#55821)
602  * where it would not handle _Static_assert in a switch case.
603  */
604 #define RTE_BUILD_BUG_ON(condition) do { static_assert(!(condition), #condition); } while (0)
605 
606 /*********** Cache line related macros ********/
607 
608 /** Cache line mask. */
609 #define RTE_CACHE_LINE_MASK (RTE_CACHE_LINE_SIZE-1)
610 
611 /** Return the first cache-aligned value greater or equal to size. */
612 #define RTE_CACHE_LINE_ROUNDUP(size) RTE_ALIGN_CEIL(size, RTE_CACHE_LINE_SIZE)
613 
614 /** Cache line size in terms of log2 */
615 #if RTE_CACHE_LINE_SIZE == 64
616 #define RTE_CACHE_LINE_SIZE_LOG2 6
617 #elif RTE_CACHE_LINE_SIZE == 128
618 #define RTE_CACHE_LINE_SIZE_LOG2 7
619 #else
620 #error "Unsupported cache line size"
621 #endif
622 
623 /** Minimum Cache line size. */
624 #define RTE_CACHE_LINE_MIN_SIZE 64
625 
626 /** Force alignment to cache line. */
627 #define __rte_cache_aligned __rte_aligned(RTE_CACHE_LINE_SIZE)
628 
629 /** Force minimum cache line alignment. */
630 #define __rte_cache_min_aligned __rte_aligned(RTE_CACHE_LINE_MIN_SIZE)
631 
632 #define _RTE_CACHE_GUARD_HELPER2(unique) \
633 	alignas(RTE_CACHE_LINE_SIZE) \
634 	char cache_guard_ ## unique[RTE_CACHE_LINE_SIZE * RTE_CACHE_GUARD_LINES]
635 #define _RTE_CACHE_GUARD_HELPER1(unique) _RTE_CACHE_GUARD_HELPER2(unique)
636 /**
637  * Empty cache lines, to guard against false sharing-like effects
638  * on systems with a next-N-lines hardware prefetcher.
639  *
640  * Use as spacing between data accessed by different lcores,
641  * to prevent cache thrashing on hardware with speculative prefetching.
642  */
643 #define RTE_CACHE_GUARD _RTE_CACHE_GUARD_HELPER1(__COUNTER__)
644 
645 /*********** PA/IOVA type definitions ********/
646 
647 /** Physical address */
648 typedef uint64_t phys_addr_t;
649 #define RTE_BAD_PHYS_ADDR ((phys_addr_t)-1)
650 
651 /**
652  * IO virtual address type.
653  * When the physical addressing mode (IOVA as PA) is in use,
654  * the translation from an IO virtual address (IOVA) to a physical address
655  * is a direct mapping, i.e. the same value.
656  * Otherwise, in virtual mode (IOVA as VA), an IOMMU may do the translation.
657  */
658 typedef uint64_t rte_iova_t;
659 #define RTE_BAD_IOVA ((rte_iova_t)-1)
660 
661 /*********** Structure alignment markers ********/
662 
663 #ifndef RTE_TOOLCHAIN_MSVC
664 
665 /** Generic marker for any place in a structure. */
666 __extension__ typedef void    *RTE_MARKER[0];
667 /** Marker for 1B alignment in a structure. */
668 __extension__ typedef uint8_t  RTE_MARKER8[0];
669 /** Marker for 2B alignment in a structure. */
670 __extension__ typedef uint16_t RTE_MARKER16[0];
671 /** Marker for 4B alignment in a structure. */
672 __extension__ typedef uint32_t RTE_MARKER32[0];
673 /** Marker for 8B alignment in a structure. */
674 __extension__ typedef uint64_t RTE_MARKER64[0];
675 
676 #endif
677 
678 /*********** Macros for calculating min and max **********/
679 
680 /**
681  * Macro to return the minimum of two numbers
682  */
683 #define RTE_MIN(a, b) \
684 	__extension__ ({ \
685 		typeof (a) _a = (a); \
686 		typeof (b) _b = (b); \
687 		_a < _b ? _a : _b; \
688 	})
689 
690 /**
691  * Macro to return the minimum of two numbers
692  *
693  * As opposed to RTE_MIN, it does not use temporary variables so it is not safe
694  * if a or b is an expression. Yet it is guaranteed to be constant for use in
695  * static_assert().
696  */
697 #define RTE_MIN_T(a, b, t) \
698 	((t)(a) < (t)(b) ? (t)(a) : (t)(b))
699 
700 /**
701  * Macro to return the maximum of two numbers
702  */
703 #define RTE_MAX(a, b) \
704 	__extension__ ({ \
705 		typeof (a) _a = (a); \
706 		typeof (b) _b = (b); \
707 		_a > _b ? _a : _b; \
708 	})
709 
710 /**
711  * Macro to return the maximum of two numbers
712  *
713  * As opposed to RTE_MAX, it does not use temporary variables so it is not safe
714  * if a or b is an expression. Yet it is guaranteed to be constant for use in
715  * static_assert().
716  */
717 #define RTE_MAX_T(a, b, t) \
718 	((t)(a) > (t)(b) ? (t)(a) : (t)(b))
719 
720 /*********** Other general functions / macros ********/
721 
722 #ifndef offsetof
723 /** Return the offset of a field in a structure. */
724 #define offsetof(TYPE, MEMBER)  __builtin_offsetof (TYPE, MEMBER)
725 #endif
726 
727 /**
728  * Return pointer to the wrapping struct instance.
729  *
730  * Example:
731  *
732  *  struct wrapper {
733  *      ...
734  *      struct child c;
735  *      ...
736  *  };
737  *
738  *  struct child *x = obtain(...);
739  *  struct wrapper *w = container_of(x, struct wrapper, c);
740  */
741 #ifndef container_of
742 #ifdef RTE_TOOLCHAIN_MSVC
743 #define container_of(ptr, type, member) \
744 			((type *)((uintptr_t)(ptr) - offsetof(type, member)))
745 #else
746 #define container_of(ptr, type, member)	__extension__ ({		\
747 			const typeof(((type *)0)->member) *_ptr = (ptr); \
748 			__rte_unused type *_target_ptr =	\
749 				(type *)(ptr);				\
750 			(type *)(((uintptr_t)_ptr) - offsetof(type, member)); \
751 		})
752 #endif
753 #endif
754 
755 /** Swap two variables. */
756 #define RTE_SWAP(a, b) \
757 	__extension__ ({ \
758 		typeof (a) _a = a; \
759 		a = b; \
760 		b = _a; \
761 	})
762 
763 /**
764  * Get the size of a field in a structure.
765  *
766  * @param type
767  *   The type of the structure.
768  * @param field
769  *   The field in the structure.
770  * @return
771  *   The size of the field in the structure, in bytes.
772  */
773 #define RTE_SIZEOF_FIELD(type, field) (sizeof(((type *)0)->field))
774 
775 #define _RTE_STR(x) #x
776 /** Take a macro value and get a string version of it */
777 #define RTE_STR(x) _RTE_STR(x)
778 
779 /**
780  * ISO C helpers to modify format strings using variadic macros.
781  * This is a replacement for the ", ## __VA_ARGS__" GNU extension.
782  * An empty %s argument is appended to avoid a dangling comma.
783  */
784 #define RTE_FMT(fmt, ...) fmt "%.0s", __VA_ARGS__ ""
785 #define RTE_FMT_HEAD(fmt, ...) fmt
786 #define RTE_FMT_TAIL(fmt, ...) __VA_ARGS__
787 
788 /** Mask value of type "tp" for the first "ln" bit set. */
789 #define	RTE_LEN2MASK(ln, tp)	\
790 	((tp)((uint64_t)-1 >> (sizeof(uint64_t) * CHAR_BIT - (ln))))
791 
792 /** Number of elements in the array. */
793 #define	RTE_DIM(a)	(sizeof (a) / sizeof ((a)[0]))
794 
795 /**
796  * Converts a numeric string to the equivalent uint64_t value.
797  * As well as straight number conversion, also recognises the suffixes
798  * k, m and g for kilobytes, megabytes and gigabytes respectively.
799  *
800  * If a negative number is passed in  i.e. a string with the first non-black
801  * character being "-", zero is returned. Zero is also returned in the case of
802  * an error with the strtoull call in the function.
803  *
804  * @param str
805  *     String containing number to convert.
806  * @return
807  *     Number.
808  */
809 uint64_t
810 rte_str_to_size(const char *str);
811 
812 /**
813  * Function to terminate the application immediately, printing an error
814  * message and returning the exit_code back to the shell.
815  *
816  * This function never returns
817  *
818  * @param exit_code
819  *     The exit code to be returned by the application
820  * @param format
821  *     The format string to be used for printing the message. This can include
822  *     printf format characters which will be expanded using any further parameters
823  *     to the function.
824  */
825 __rte_noreturn void
826 rte_exit(int exit_code, const char *format, ...)
827 	__rte_format_printf(2, 3);
828 
829 #ifdef __cplusplus
830 }
831 #endif
832 
833 #endif
834