xref: /freebsd/sys/compat/linuxkpi/common/include/linux/kernel.h (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
6  * Copyright (c) 2014-2015 François Tigeot
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice unmodified, this list of conditions, and the following
14  *    disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 #ifndef	_LINUXKPI_LINUX_KERNEL_H_
31 #define	_LINUXKPI_LINUX_KERNEL_H_
32 
33 #include <sys/cdefs.h>
34 #include <sys/types.h>
35 #include <sys/systm.h>
36 #include <sys/param.h>
37 #include <sys/libkern.h>
38 #include <sys/stat.h>
39 #include <sys/smp.h>
40 #include <sys/stddef.h>
41 #include <sys/syslog.h>
42 #include <sys/time.h>
43 
44 #include <linux/bitops.h>
45 #include <linux/compiler.h>
46 #include <linux/stringify.h>
47 #include <linux/errno.h>
48 #include <linux/sched.h>
49 #include <linux/types.h>
50 #include <linux/typecheck.h>
51 #include <linux/jiffies.h>
52 #include <linux/log2.h>
53 #include <linux/kconfig.h>
54 
55 #include <asm/byteorder.h>
56 #include <asm/cpufeature.h>
57 #include <asm/processor.h>
58 #include <asm/uaccess.h>
59 
60 #include <linux/stdarg.h>
61 
62 #define KERN_CONT       ""
63 #define	KERN_EMERG	"<0>"
64 #define	KERN_ALERT	"<1>"
65 #define	KERN_CRIT	"<2>"
66 #define	KERN_ERR	"<3>"
67 #define	KERN_WARNING	"<4>"
68 #define	KERN_NOTICE	"<5>"
69 #define	KERN_INFO	"<6>"
70 #define	KERN_DEBUG	"<7>"
71 
72 #define	U8_MAX		((u8)~0U)
73 #define	S8_MAX		((s8)(U8_MAX >> 1))
74 #define	S8_MIN		((s8)(-S8_MAX - 1))
75 #define	U16_MAX		((u16)~0U)
76 #define	S16_MAX		((s16)(U16_MAX >> 1))
77 #define	S16_MIN		((s16)(-S16_MAX - 1))
78 #define	U32_MAX		((u32)~0U)
79 #define	S32_MAX		((s32)(U32_MAX >> 1))
80 #define	S32_MIN		((s32)(-S32_MAX - 1))
81 #define	U64_MAX		((u64)~0ULL)
82 #define	S64_MAX		((s64)(U64_MAX >> 1))
83 #define	S64_MIN		((s64)(-S64_MAX - 1))
84 
85 #define	S8_C(x)  x
86 #define	U8_C(x)  x ## U
87 #define	S16_C(x) x
88 #define	U16_C(x) x ## U
89 #define	S32_C(x) x
90 #define	U32_C(x) x ## U
91 #define	S64_C(x) x ## LL
92 #define	U64_C(x) x ## ULL
93 
94 /*
95  * BUILD_BUG_ON() can happen inside functions where _Static_assert() does not
96  * seem to work.  Use old-schoold-ish CTASSERT from before commit
97  * a3085588a88fa58eb5b1eaae471999e1995a29cf but also make sure we do not
98  * end up with an unused typedef or variable. The compiler should optimise
99  * it away entirely.
100  */
101 #define	_O_CTASSERT(x)		_O__CTASSERT(x, __LINE__)
102 #define	_O__CTASSERT(x, y)	_O___CTASSERT(x, y)
103 #define	_O___CTASSERT(x, y)	while (0) { \
104     typedef char __unused __assert_line_ ## y[(x) ? 1 : -1]; \
105     __assert_line_ ## y _x; \
106     _x[0] = '\0'; \
107 }
108 
109 #define	BUILD_BUG()			do { CTASSERT(0); } while (0)
110 #define	BUILD_BUG_ON(x)			do { _O_CTASSERT(!(x)) } while (0)
111 #define	BUILD_BUG_ON_MSG(x, msg)	BUILD_BUG_ON(x)
112 #define	BUILD_BUG_ON_NOT_POWER_OF_2(x)	BUILD_BUG_ON(!powerof2(x))
113 #define	BUILD_BUG_ON_INVALID(expr)	while (0) { (void)(expr); }
114 #define	BUILD_BUG_ON_ZERO(x)	((int)sizeof(struct { int:-((x) != 0); }))
115 
116 #define	BUG()			panic("BUG at %s:%d", __FILE__, __LINE__)
117 #define	BUG_ON(cond)		do {				\
118 	if (cond) {						\
119 		panic("BUG ON %s failed at %s:%d",		\
120 		    __stringify(cond), __FILE__, __LINE__);	\
121 	}							\
122 } while (0)
123 
124 extern int linuxkpi_warn_dump_stack;
125 #define	WARN_ON(cond) ({					\
126 	bool __ret = (cond);					\
127 	if (__ret) {						\
128 		printf("WARNING %s failed at %s:%d\n",		\
129 		    __stringify(cond), __FILE__, __LINE__);	\
130 		if (linuxkpi_warn_dump_stack)				\
131 			linux_dump_stack();				\
132 	}								\
133 	unlikely(__ret);						\
134 })
135 
136 #define	WARN_ON_SMP(cond)	WARN_ON(cond)
137 
138 #define	WARN_ON_ONCE(cond) ({					\
139 	static bool __warn_on_once;				\
140 	bool __ret = (cond);					\
141 	if (__ret && !__warn_on_once) {				\
142 		__warn_on_once = 1;				\
143 		printf("WARNING %s failed at %s:%d\n",		\
144 		    __stringify(cond), __FILE__, __LINE__);	\
145 		if (linuxkpi_warn_dump_stack)				\
146 			linux_dump_stack();				\
147 	}								\
148 	unlikely(__ret);						\
149 })
150 
151 #define	oops_in_progress	SCHEDULER_STOPPED()
152 
153 #undef	ALIGN
154 #define	ALIGN(x, y)		roundup2((x), (y))
155 #define	ALIGN_DOWN(x, y)	rounddown2(x, y)
156 #undef PTR_ALIGN
157 #define	PTR_ALIGN(p, a)		((__typeof(p))ALIGN((uintptr_t)(p), (a)))
158 #define	IS_ALIGNED(x, a)	(((x) & ((__typeof(x))(a) - 1)) == 0)
159 #define	DIV_ROUND_UP(x, n)	howmany(x, n)
160 #define	__KERNEL_DIV_ROUND_UP(x, n)	howmany(x, n)
161 #define	DIV_ROUND_UP_ULL(x, n)	DIV_ROUND_UP((unsigned long long)(x), (n))
162 #define	DIV_ROUND_DOWN_ULL(x, n) (((unsigned long long)(x) / (n)) * (n))
163 #define	FIELD_SIZEOF(t, f)	sizeof(((t *)0)->f)
164 
165 #define	printk(...)		printf(__VA_ARGS__)
166 #define	vprintk(f, a)		vprintf(f, a)
167 
168 #define	asm			__asm
169 
170 extern void linux_dump_stack(void);
171 #define	dump_stack()		linux_dump_stack()
172 
173 struct va_format {
174 	const char *fmt;
175 	va_list *va;
176 };
177 
178 static inline int
179 vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
180 {
181 	ssize_t ssize = size;
182 	int i;
183 
184 	i = vsnprintf(buf, size, fmt, args);
185 
186 	return ((i >= ssize) ? (ssize - 1) : i);
187 }
188 
189 static inline int
190 scnprintf(char *buf, size_t size, const char *fmt, ...)
191 {
192 	va_list args;
193 	int i;
194 
195 	va_start(args, fmt);
196 	i = vscnprintf(buf, size, fmt, args);
197 	va_end(args);
198 
199 	return (i);
200 }
201 
202 /*
203  * The "pr_debug()" and "pr_devel()" macros should produce zero code
204  * unless DEBUG is defined:
205  */
206 #ifdef DEBUG
207 extern int linuxkpi_debug;
208 #define pr_debug(fmt, ...)					\
209 	do {							\
210 		if (linuxkpi_debug)				\
211 			log(LOG_DEBUG, fmt, ##__VA_ARGS__);	\
212 	} while (0)
213 #define pr_devel(fmt, ...) \
214 	log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__)
215 #else
216 #define pr_debug(fmt, ...) \
217 	({ if (0) log(LOG_DEBUG, fmt, ##__VA_ARGS__); 0; })
218 #define pr_devel(fmt, ...) \
219 	({ if (0) log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__); 0; })
220 #endif
221 
222 #ifndef pr_fmt
223 #define pr_fmt(fmt) fmt
224 #endif
225 
226 /*
227  * Print a one-time message (analogous to WARN_ONCE() et al):
228  */
229 #define printk_once(...) do {			\
230 	static bool __print_once;		\
231 						\
232 	if (!__print_once) {			\
233 		__print_once = true;		\
234 		printk(__VA_ARGS__);		\
235 	}					\
236 } while (0)
237 
238 /*
239  * Log a one-time message (analogous to WARN_ONCE() et al):
240  */
241 #define log_once(level,...) do {		\
242 	static bool __log_once;			\
243 						\
244 	if (unlikely(!__log_once)) {		\
245 		__log_once = true;		\
246 		log(level, __VA_ARGS__);	\
247 	}					\
248 } while (0)
249 
250 #define pr_emerg(fmt, ...) \
251 	log(LOG_EMERG, pr_fmt(fmt), ##__VA_ARGS__)
252 #define pr_alert(fmt, ...) \
253 	log(LOG_ALERT, pr_fmt(fmt), ##__VA_ARGS__)
254 #define pr_crit(fmt, ...) \
255 	log(LOG_CRIT, pr_fmt(fmt), ##__VA_ARGS__)
256 #define pr_err(fmt, ...) \
257 	log(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__)
258 #define pr_err_once(fmt, ...) \
259 	log_once(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__)
260 #define pr_warning(fmt, ...) \
261 	log(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__)
262 #define pr_warn(...) \
263 	pr_warning(__VA_ARGS__)
264 #define pr_warn_once(fmt, ...) \
265 	log_once(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__)
266 #define pr_notice(fmt, ...) \
267 	log(LOG_NOTICE, pr_fmt(fmt), ##__VA_ARGS__)
268 #define pr_info(fmt, ...) \
269 	log(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__)
270 #define pr_info_once(fmt, ...) \
271 	log_once(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__)
272 #define pr_cont(fmt, ...) \
273 	printk(KERN_CONT fmt, ##__VA_ARGS__)
274 #define	pr_warn_ratelimited(...) do {		\
275 	static linux_ratelimit_t __ratelimited;	\
276 	if (linux_ratelimited(&__ratelimited))	\
277 		pr_warning(__VA_ARGS__);	\
278 } while (0)
279 
280 #ifndef WARN
281 #define	WARN(condition, ...) ({			\
282 	bool __ret_warn_on = (condition);	\
283 	if (unlikely(__ret_warn_on))		\
284 		pr_warning(__VA_ARGS__);	\
285 	unlikely(__ret_warn_on);		\
286 })
287 #endif
288 
289 #ifndef WARN_ONCE
290 #define	WARN_ONCE(condition, ...) ({		\
291 	bool __ret_warn_on = (condition);	\
292 	if (unlikely(__ret_warn_on))		\
293 		pr_warn_once(__VA_ARGS__);	\
294 	unlikely(__ret_warn_on);		\
295 })
296 #endif
297 
298 #define container_of(ptr, type, member)				\
299 ({								\
300 	const __typeof(((type *)0)->member) *__p = (ptr);	\
301 	(type *)((uintptr_t)__p - offsetof(type, member));	\
302 })
303 
304 #define	ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
305 
306 #define	u64_to_user_ptr(val)	((void *)(uintptr_t)(val))
307 
308 #define _RET_IP_		__builtin_return_address(0)
309 
310 static inline unsigned long long
311 simple_strtoull(const char *cp, char **endp, unsigned int base)
312 {
313 	return (strtouq(cp, endp, base));
314 }
315 
316 static inline long long
317 simple_strtoll(const char *cp, char **endp, unsigned int base)
318 {
319 	return (strtoq(cp, endp, base));
320 }
321 
322 static inline unsigned long
323 simple_strtoul(const char *cp, char **endp, unsigned int base)
324 {
325 	return (strtoul(cp, endp, base));
326 }
327 
328 static inline long
329 simple_strtol(const char *cp, char **endp, unsigned int base)
330 {
331 	return (strtol(cp, endp, base));
332 }
333 
334 static inline int
335 kstrtoul(const char *cp, unsigned int base, unsigned long *res)
336 {
337 	char *end;
338 
339 	*res = strtoul(cp, &end, base);
340 
341 	/* skip newline character, if any */
342 	if (*end == '\n')
343 		end++;
344 	if (*cp == 0 || *end != 0)
345 		return (-EINVAL);
346 	return (0);
347 }
348 
349 static inline int
350 kstrtol(const char *cp, unsigned int base, long *res)
351 {
352 	char *end;
353 
354 	*res = strtol(cp, &end, base);
355 
356 	/* skip newline character, if any */
357 	if (*end == '\n')
358 		end++;
359 	if (*cp == 0 || *end != 0)
360 		return (-EINVAL);
361 	return (0);
362 }
363 
364 static inline int
365 kstrtoint(const char *cp, unsigned int base, int *res)
366 {
367 	char *end;
368 	long temp;
369 
370 	*res = temp = strtol(cp, &end, base);
371 
372 	/* skip newline character, if any */
373 	if (*end == '\n')
374 		end++;
375 	if (*cp == 0 || *end != 0)
376 		return (-EINVAL);
377 	if (temp != (int)temp)
378 		return (-ERANGE);
379 	return (0);
380 }
381 
382 static inline int
383 kstrtouint(const char *cp, unsigned int base, unsigned int *res)
384 {
385 	char *end;
386 	unsigned long temp;
387 
388 	*res = temp = strtoul(cp, &end, base);
389 
390 	/* skip newline character, if any */
391 	if (*end == '\n')
392 		end++;
393 	if (*cp == 0 || *end != 0)
394 		return (-EINVAL);
395 	if (temp != (unsigned int)temp)
396 		return (-ERANGE);
397 	return (0);
398 }
399 
400 static inline int
401 kstrtou8(const char *cp, unsigned int base, u8 *res)
402 {
403 	char *end;
404 	unsigned long temp;
405 
406 	*res = temp = strtoul(cp, &end, base);
407 
408 	/* skip newline character, if any */
409 	if (*end == '\n')
410 		end++;
411 	if (*cp == 0 || *end != 0)
412 		return (-EINVAL);
413 	if (temp != (u8)temp)
414 		return (-ERANGE);
415 	return (0);
416 }
417 
418 static inline int
419 kstrtou16(const char *cp, unsigned int base, u16 *res)
420 {
421 	char *end;
422 	unsigned long temp;
423 
424 	*res = temp = strtoul(cp, &end, base);
425 
426 	/* skip newline character, if any */
427 	if (*end == '\n')
428 		end++;
429 	if (*cp == 0 || *end != 0)
430 		return (-EINVAL);
431 	if (temp != (u16)temp)
432 		return (-ERANGE);
433 	return (0);
434 }
435 
436 static inline int
437 kstrtou32(const char *cp, unsigned int base, u32 *res)
438 {
439 
440 	return (kstrtouint(cp, base, res));
441 }
442 
443 static inline int
444 kstrtou64(const char *cp, unsigned int base, u64 *res)
445 {
446        char *end;
447 
448        *res = strtouq(cp, &end, base);
449 
450        /* skip newline character, if any */
451        if (*end == '\n')
452                end++;
453        if (*cp == 0 || *end != 0)
454                return (-EINVAL);
455        return (0);
456 }
457 
458 static inline int
459 kstrtoull(const char *cp, unsigned int base, unsigned long long *res)
460 {
461 	return (kstrtou64(cp, base, (u64 *)res));
462 }
463 
464 static inline int
465 kstrtobool(const char *s, bool *res)
466 {
467 	int len;
468 
469 	if (s == NULL || (len = strlen(s)) == 0 || res == NULL)
470 		return (-EINVAL);
471 
472 	/* skip newline character, if any */
473 	if (s[len - 1] == '\n')
474 		len--;
475 
476 	if (len == 1 && strchr("yY1", s[0]) != NULL)
477 		*res = true;
478 	else if (len == 1 && strchr("nN0", s[0]) != NULL)
479 		*res = false;
480 	else if (strncasecmp("on", s, len) == 0)
481 		*res = true;
482 	else if (strncasecmp("off", s, len) == 0)
483 		*res = false;
484 	else
485 		return (-EINVAL);
486 
487 	return (0);
488 }
489 
490 static inline int
491 kstrtobool_from_user(const char __user *s, size_t count, bool *res)
492 {
493 	char buf[8] = {};
494 
495 	if (count > (sizeof(buf) - 1))
496 		count = (sizeof(buf) - 1);
497 
498 	if (copy_from_user(buf, s, count))
499 		return (-EFAULT);
500 
501 	return (kstrtobool(buf, res));
502 }
503 
504 static inline int
505 kstrtoint_from_user(const char __user *s, size_t count, unsigned int base,
506     int *p)
507 {
508 	char buf[36] = {};
509 
510 	if (count > (sizeof(buf) - 1))
511 		count = (sizeof(buf) - 1);
512 
513 	if (copy_from_user(buf, s, count))
514 		return (-EFAULT);
515 
516 	return (kstrtoint(buf, base, p));
517 }
518 
519 static inline int
520 kstrtouint_from_user(const char __user *s, size_t count, unsigned int base,
521     unsigned int *p)
522 {
523 	char buf[36] = {};
524 
525 	if (count > (sizeof(buf) - 1))
526 		count = (sizeof(buf) - 1);
527 
528 	if (copy_from_user(buf, s, count))
529 		return (-EFAULT);
530 
531 	return (kstrtouint(buf, base, p));
532 }
533 
534 static inline int
535 kstrtou32_from_user(const char __user *s, size_t count, unsigned int base,
536     unsigned int *p)
537 {
538 
539 	return (kstrtouint_from_user(s, count, base, p));
540 }
541 
542 static inline int
543 kstrtou8_from_user(const char __user *s, size_t count, unsigned int base,
544     u8 *p)
545 {
546 	char buf[8] = {};
547 
548 	if (count > (sizeof(buf) - 1))
549 		count = (sizeof(buf) - 1);
550 
551 	if (copy_from_user(buf, s, count))
552 		return (-EFAULT);
553 
554 	return (kstrtou8(buf, base, p));
555 }
556 
557 #define min(x, y)	((x) < (y) ? (x) : (y))
558 #define max(x, y)	((x) > (y) ? (x) : (y))
559 
560 #define min3(a, b, c)	min(a, min(b,c))
561 #define max3(a, b, c)	max(a, max(b,c))
562 
563 #define	min_t(type, x, y) ({			\
564 	type __min1 = (x);			\
565 	type __min2 = (y);			\
566 	__min1 < __min2 ? __min1 : __min2; })
567 
568 #define	max_t(type, x, y) ({			\
569 	type __max1 = (x);			\
570 	type __max2 = (y);			\
571 	__max1 > __max2 ? __max1 : __max2; })
572 
573 #define offsetofend(t, m)	\
574         (offsetof(t, m) + sizeof((((t *)0)->m)))
575 
576 #define	typeof_member(s, e)	typeof(((s *)0)->e)
577 
578 #define clamp_t(type, _x, min, max)	min_t(type, max_t(type, _x, min), max)
579 #define clamp(x, lo, hi)		min( max(x,lo), hi)
580 #define	clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
581 
582 /*
583  * This looks more complex than it should be. But we need to
584  * get the type for the ~ right in round_down (it needs to be
585  * as wide as the result!), and we want to evaluate the macro
586  * arguments just once each.
587  */
588 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
589 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
590 #define round_down(x, y) ((x) & ~__round_mask(x, y))
591 
592 #define	smp_processor_id()	PCPU_GET(cpuid)
593 #define	num_possible_cpus()	mp_ncpus
594 #define	num_online_cpus()	mp_ncpus
595 
596 #if defined(__i386__) || defined(__amd64__)
597 extern bool linux_cpu_has_clflush;
598 #define	cpu_has_clflush		linux_cpu_has_clflush
599 #endif
600 
601 /* Swap values of a and b */
602 #define swap(a, b) do {			\
603 	typeof(a) _swap_tmp = a;	\
604 	a = b;				\
605 	b = _swap_tmp;			\
606 } while (0)
607 
608 #define	DIV_ROUND_CLOSEST(x, divisor)	(((x) + ((divisor) / 2)) / (divisor))
609 
610 #define	DIV_ROUND_CLOSEST_ULL(x, divisor) ({		\
611 	__typeof(divisor) __d = (divisor);		\
612 	unsigned long long __ret = (x) + (__d) / 2;	\
613 	__ret /= __d;					\
614 	__ret;						\
615 })
616 
617 static inline uintmax_t
618 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor)
619 {
620 	uintmax_t q = (x / divisor);
621 	uintmax_t r = (x % divisor);
622 
623 	return ((q * multiplier) + ((r * multiplier) / divisor));
624 }
625 
626 static inline int64_t
627 abs64(int64_t x)
628 {
629 	return (x < 0 ? -x : x);
630 }
631 
632 typedef struct linux_ratelimit {
633 	struct timeval lasttime;
634 	int counter;
635 } linux_ratelimit_t;
636 
637 static inline bool
638 linux_ratelimited(linux_ratelimit_t *rl)
639 {
640 	return (ppsratecheck(&rl->lasttime, &rl->counter, 1));
641 }
642 
643 #define	struct_size(ptr, field, num) ({ \
644 	const size_t __size = offsetof(__typeof(*(ptr)), field); \
645 	const size_t __max = (SIZE_MAX - __size) / sizeof((ptr)->field[0]); \
646 	((num) > __max) ? SIZE_MAX : (__size + sizeof((ptr)->field[0]) * (num)); \
647 })
648 
649 #define	__is_constexpr(x) \
650 	__builtin_constant_p(x)
651 
652 /*
653  * The is_signed() macro below returns true if the passed data type is
654  * signed. Else false is returned.
655  */
656 #define	is_signed(datatype) (((datatype)-1 / (datatype)2) == (datatype)0)
657 
658 /*
659  * The type_max() macro below returns the maxium positive value the
660  * passed data type can hold.
661  */
662 #define	type_max(datatype) ( \
663   (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MAX : UINT64_MAX) : \
664   (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MAX : UINT32_MAX) : \
665   (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MAX : UINT16_MAX) : \
666 			    (is_signed(datatype) ? INT8_MAX : UINT8_MAX) \
667 )
668 
669 /*
670  * The type_min() macro below returns the minimum value the passed
671  * data type can hold. For unsigned types the minimum value is always
672  * zero. For signed types it may vary.
673  */
674 #define	type_min(datatype) ( \
675   (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MIN : 0) : \
676   (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MIN : 0) : \
677   (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MIN : 0) : \
678 			    (is_signed(datatype) ? INT8_MIN : 0) \
679 )
680 
681 #define	TAINT_WARN	0
682 #define	test_taint(x)	(0)
683 #define	add_taint(x,y)	do {	\
684 	} while (0)
685 
686 static inline int
687 _h2b(const char c)
688 {
689 
690 	if (c >= '0' && c <= '9')
691 		return (c - '0');
692 	if (c >= 'a' && c <= 'f')
693 		return (10 + c - 'a');
694 	if (c >= 'A' && c <= 'F')
695 		return (10 + c - 'A');
696 	return (-EINVAL);
697 }
698 
699 static inline int
700 hex2bin(uint8_t *bindst, const char *hexsrc, size_t binlen)
701 {
702 	int hi4, lo4;
703 
704 	while (binlen > 0) {
705 		hi4 = _h2b(*hexsrc++);
706 		lo4 = _h2b(*hexsrc++);
707 		if (hi4 < 0 || lo4 < 0)
708 			return (-EINVAL);
709 
710 		*bindst++ = (hi4 << 4) | lo4;
711 		binlen--;
712 	}
713 
714 	return (0);
715 }
716 
717 static inline bool
718 mac_pton(const char *macin, uint8_t *macout)
719 {
720 	const char *s, *d;
721 	uint8_t mac[6], hx, lx;;
722 	int i;
723 
724 	if (strlen(macin) < (3 * 6 - 1))
725 		return (false);
726 
727 	i = 0;
728 	s = macin;
729 	do {
730 		/* Should we also support '-'-delimiters? */
731 		d = strchrnul(s, ':');
732 		hx = lx = 0;
733 		while (s < d) {
734 			/* Fail on abc:123:xxx:... */
735 			if ((d - s) > 2)
736 				return (false);
737 			/* We do support non-well-formed strings: 3:45:6:... */
738 			if ((d - s) > 1) {
739 				hx = _h2b(*s);
740 				if (hx < 0)
741 					return (false);
742 				s++;
743 			}
744 			lx = _h2b(*s);
745 			if (lx < 0)
746 				return (false);
747 			s++;
748 		}
749 		mac[i] = (hx << 4) | lx;
750 		i++;
751 		if (i >= 6)
752 			return (false);
753 	} while (d != NULL && *d != '\0');
754 
755 	memcpy(macout, mac, 6);
756 	return (true);
757 }
758 
759 #define	DECLARE_FLEX_ARRAY(_t, _n)					\
760     struct { struct { } __dummy_ ## _n; _t _n[0]; }
761 
762 #endif	/* _LINUXKPI_LINUX_KERNEL_H_ */
763