xref: /freebsd/sys/compat/linuxkpi/common/include/linux/kernel.h (revision b197d4b893974c9eb4d7b38704c6d5c486235d6f)
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  * $FreeBSD$
31  */
32 #ifndef	_LINUXKPI_LINUX_KERNEL_H_
33 #define	_LINUXKPI_LINUX_KERNEL_H_
34 
35 #include <sys/cdefs.h>
36 #include <sys/types.h>
37 #include <sys/systm.h>
38 #include <sys/param.h>
39 #include <sys/libkern.h>
40 #include <sys/stat.h>
41 #include <sys/smp.h>
42 #include <sys/stddef.h>
43 #include <sys/syslog.h>
44 #include <sys/time.h>
45 
46 #include <linux/bitops.h>
47 #include <linux/compiler.h>
48 #include <linux/stringify.h>
49 #include <linux/errno.h>
50 #include <linux/sched.h>
51 #include <linux/types.h>
52 #include <linux/typecheck.h>
53 #include <linux/jiffies.h>
54 #include <linux/log2.h>
55 
56 #include <asm/byteorder.h>
57 #include <asm/cpufeature.h>
58 #include <asm/processor.h>
59 #include <asm/uaccess.h>
60 
61 #include <machine/stdarg.h>
62 
63 #define KERN_CONT       ""
64 #define	KERN_EMERG	"<0>"
65 #define	KERN_ALERT	"<1>"
66 #define	KERN_CRIT	"<2>"
67 #define	KERN_ERR	"<3>"
68 #define	KERN_WARNING	"<4>"
69 #define	KERN_NOTICE	"<5>"
70 #define	KERN_INFO	"<6>"
71 #define	KERN_DEBUG	"<7>"
72 
73 #define	U8_MAX		((u8)~0U)
74 #define	S8_MAX		((s8)(U8_MAX >> 1))
75 #define	S8_MIN		((s8)(-S8_MAX - 1))
76 #define	U16_MAX		((u16)~0U)
77 #define	S16_MAX		((s16)(U16_MAX >> 1))
78 #define	S16_MIN		((s16)(-S16_MAX - 1))
79 #define	U32_MAX		((u32)~0U)
80 #define	S32_MAX		((s32)(U32_MAX >> 1))
81 #define	S32_MIN		((s32)(-S32_MAX - 1))
82 #define	U64_MAX		((u64)~0ULL)
83 #define	S64_MAX		((s64)(U64_MAX >> 1))
84 #define	S64_MIN		((s64)(-S64_MAX - 1))
85 
86 #define	S8_C(x)  x
87 #define	U8_C(x)  x ## U
88 #define	S16_C(x) x
89 #define	U16_C(x) x ## U
90 #define	S32_C(x) x
91 #define	U32_C(x) x ## U
92 #define	S64_C(x) x ## LL
93 #define	U64_C(x) x ## ULL
94 
95 /*
96  * BUILD_BUG_ON() can happen inside functions where _Static_assert() does not
97  * seem to work.  Use old-schoold-ish CTASSERT from before commit
98  * a3085588a88fa58eb5b1eaae471999e1995a29cf but also make sure we do not
99  * end up with an unused typedef or variable. The compiler should optimise
100  * it away entirely.
101  */
102 #define	_O_CTASSERT(x)		_O__CTASSERT(x, __LINE__)
103 #define	_O__CTASSERT(x, y)	_O___CTASSERT(x, y)
104 #define	_O___CTASSERT(x, y)	while (0) { \
105     typedef char __assert_line_ ## y[(x) ? 1 : -1]; \
106     __assert_line_ ## y _x; \
107     _x[0] = '\0'; \
108 }
109 
110 #define	BUILD_BUG()			do { CTASSERT(0); } while (0)
111 #define	BUILD_BUG_ON(x)			do { _O_CTASSERT(!(x)) } while (0)
112 #define	BUILD_BUG_ON_MSG(x, msg)	BUILD_BUG_ON(x)
113 #define	BUILD_BUG_ON_NOT_POWER_OF_2(x)	BUILD_BUG_ON(!powerof2(x))
114 #define	BUILD_BUG_ON_INVALID(expr)	while (0) { (void)(expr); }
115 #define	BUILD_BUG_ON_ZERO(x)	((int)sizeof(struct { int:-((x) != 0); }))
116 
117 #define	BUG()			panic("BUG at %s:%d", __FILE__, __LINE__)
118 #define	BUG_ON(cond)		do {				\
119 	if (cond) {						\
120 		panic("BUG ON %s failed at %s:%d",		\
121 		    __stringify(cond), __FILE__, __LINE__);	\
122 	}							\
123 } while (0)
124 
125 extern int linuxkpi_warn_dump_stack;
126 #define	WARN_ON(cond) ({					\
127 	bool __ret = (cond);					\
128 	if (__ret) {						\
129 		printf("WARNING %s failed at %s:%d\n",		\
130 		    __stringify(cond), __FILE__, __LINE__);	\
131 		if (linuxkpi_warn_dump_stack)				\
132 			linux_dump_stack();				\
133 	}								\
134 	unlikely(__ret);						\
135 })
136 
137 #define	WARN_ON_SMP(cond)	WARN_ON(cond)
138 
139 #define	WARN_ON_ONCE(cond) ({					\
140 	static bool __warn_on_once;				\
141 	bool __ret = (cond);					\
142 	if (__ret && !__warn_on_once) {				\
143 		__warn_on_once = 1;				\
144 		printf("WARNING %s failed at %s:%d\n",		\
145 		    __stringify(cond), __FILE__, __LINE__);	\
146 		if (linuxkpi_warn_dump_stack)				\
147 			linux_dump_stack();				\
148 	}								\
149 	unlikely(__ret);						\
150 })
151 
152 #define	oops_in_progress	SCHEDULER_STOPPED()
153 
154 #undef	ALIGN
155 #define	ALIGN(x, y)		roundup2((x), (y))
156 #define	ALIGN_DOWN(x, y)	rounddown2(x, y)
157 #undef PTR_ALIGN
158 #define	PTR_ALIGN(p, a)		((__typeof(p))ALIGN((uintptr_t)(p), (a)))
159 #define	IS_ALIGNED(x, a)	(((x) & ((__typeof(x))(a) - 1)) == 0)
160 #define	DIV_ROUND_UP(x, n)	howmany(x, n)
161 #define	__KERNEL_DIV_ROUND_UP(x, n)	howmany(x, n)
162 #define	DIV_ROUND_UP_ULL(x, n)	DIV_ROUND_UP((unsigned long long)(x), (n))
163 #define	DIV_ROUND_DOWN_ULL(x, n) (((unsigned long long)(x) / (n)) * (n))
164 #define	FIELD_SIZEOF(t, f)	sizeof(((t *)0)->f)
165 
166 #define	printk(...)		printf(__VA_ARGS__)
167 #define	vprintk(f, a)		vprintf(f, a)
168 
169 #define	asm			__asm
170 
171 extern void linux_dump_stack(void);
172 #define	dump_stack()		linux_dump_stack()
173 
174 struct va_format {
175 	const char *fmt;
176 	va_list *va;
177 };
178 
179 static inline int
180 vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
181 {
182 	ssize_t ssize = size;
183 	int i;
184 
185 	i = vsnprintf(buf, size, fmt, args);
186 
187 	return ((i >= ssize) ? (ssize - 1) : i);
188 }
189 
190 static inline int
191 scnprintf(char *buf, size_t size, const char *fmt, ...)
192 {
193 	va_list args;
194 	int i;
195 
196 	va_start(args, fmt);
197 	i = vscnprintf(buf, size, fmt, args);
198 	va_end(args);
199 
200 	return (i);
201 }
202 
203 /*
204  * The "pr_debug()" and "pr_devel()" macros should produce zero code
205  * unless DEBUG is defined:
206  */
207 #ifdef DEBUG
208 extern int linuxkpi_debug;
209 #define pr_debug(fmt, ...)					\
210 	do {							\
211 		if (linuxkpi_debug)				\
212 			log(LOG_DEBUG, fmt, ##__VA_ARGS__);	\
213 	} while (0)
214 #define pr_devel(fmt, ...) \
215 	log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__)
216 #else
217 #define pr_debug(fmt, ...) \
218 	({ if (0) log(LOG_DEBUG, fmt, ##__VA_ARGS__); 0; })
219 #define pr_devel(fmt, ...) \
220 	({ if (0) log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__); 0; })
221 #endif
222 
223 #ifndef pr_fmt
224 #define pr_fmt(fmt) fmt
225 #endif
226 
227 /*
228  * Print a one-time message (analogous to WARN_ONCE() et al):
229  */
230 #define printk_once(...) do {			\
231 	static bool __print_once;		\
232 						\
233 	if (!__print_once) {			\
234 		__print_once = true;		\
235 		printk(__VA_ARGS__);		\
236 	}					\
237 } while (0)
238 
239 /*
240  * Log a one-time message (analogous to WARN_ONCE() et al):
241  */
242 #define log_once(level,...) do {		\
243 	static bool __log_once;			\
244 						\
245 	if (unlikely(!__log_once)) {		\
246 		__log_once = true;		\
247 		log(level, __VA_ARGS__);	\
248 	}					\
249 } while (0)
250 
251 #define pr_emerg(fmt, ...) \
252 	log(LOG_EMERG, pr_fmt(fmt), ##__VA_ARGS__)
253 #define pr_alert(fmt, ...) \
254 	log(LOG_ALERT, pr_fmt(fmt), ##__VA_ARGS__)
255 #define pr_crit(fmt, ...) \
256 	log(LOG_CRIT, pr_fmt(fmt), ##__VA_ARGS__)
257 #define pr_err(fmt, ...) \
258 	log(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__)
259 #define pr_err_once(fmt, ...) \
260 	log_once(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__)
261 #define pr_warning(fmt, ...) \
262 	log(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__)
263 #define pr_warn(...) \
264 	pr_warning(__VA_ARGS__)
265 #define pr_warn_once(fmt, ...) \
266 	log_once(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__)
267 #define pr_notice(fmt, ...) \
268 	log(LOG_NOTICE, pr_fmt(fmt), ##__VA_ARGS__)
269 #define pr_info(fmt, ...) \
270 	log(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__)
271 #define pr_info_once(fmt, ...) \
272 	log_once(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__)
273 #define pr_cont(fmt, ...) \
274 	printk(KERN_CONT fmt, ##__VA_ARGS__)
275 #define	pr_warn_ratelimited(...) do {		\
276 	static linux_ratelimit_t __ratelimited;	\
277 	if (linux_ratelimited(&__ratelimited))	\
278 		pr_warning(__VA_ARGS__);	\
279 } while (0)
280 
281 #ifndef WARN
282 #define	WARN(condition, ...) ({			\
283 	bool __ret_warn_on = (condition);	\
284 	if (unlikely(__ret_warn_on))		\
285 		pr_warning(__VA_ARGS__);	\
286 	unlikely(__ret_warn_on);		\
287 })
288 #endif
289 
290 #ifndef WARN_ONCE
291 #define	WARN_ONCE(condition, ...) ({		\
292 	bool __ret_warn_on = (condition);	\
293 	if (unlikely(__ret_warn_on))		\
294 		pr_warn_once(__VA_ARGS__);	\
295 	unlikely(__ret_warn_on);		\
296 })
297 #endif
298 
299 #define container_of(ptr, type, member)				\
300 ({								\
301 	const __typeof(((type *)0)->member) *__p = (ptr);	\
302 	(type *)((uintptr_t)__p - offsetof(type, member));	\
303 })
304 
305 #define	ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
306 
307 #define	u64_to_user_ptr(val)	((void *)(uintptr_t)(val))
308 
309 #define _RET_IP_		__builtin_return_address(0)
310 
311 static inline unsigned long long
312 simple_strtoull(const char *cp, char **endp, unsigned int base)
313 {
314 	return (strtouq(cp, endp, base));
315 }
316 
317 static inline long long
318 simple_strtoll(const char *cp, char **endp, unsigned int base)
319 {
320 	return (strtoq(cp, endp, base));
321 }
322 
323 static inline unsigned long
324 simple_strtoul(const char *cp, char **endp, unsigned int base)
325 {
326 	return (strtoul(cp, endp, base));
327 }
328 
329 static inline long
330 simple_strtol(const char *cp, char **endp, unsigned int base)
331 {
332 	return (strtol(cp, endp, base));
333 }
334 
335 static inline int
336 kstrtoul(const char *cp, unsigned int base, unsigned long *res)
337 {
338 	char *end;
339 
340 	*res = strtoul(cp, &end, base);
341 
342 	/* skip newline character, if any */
343 	if (*end == '\n')
344 		end++;
345 	if (*cp == 0 || *end != 0)
346 		return (-EINVAL);
347 	return (0);
348 }
349 
350 static inline int
351 kstrtol(const char *cp, unsigned int base, long *res)
352 {
353 	char *end;
354 
355 	*res = strtol(cp, &end, base);
356 
357 	/* skip newline character, if any */
358 	if (*end == '\n')
359 		end++;
360 	if (*cp == 0 || *end != 0)
361 		return (-EINVAL);
362 	return (0);
363 }
364 
365 static inline int
366 kstrtoint(const char *cp, unsigned int base, int *res)
367 {
368 	char *end;
369 	long temp;
370 
371 	*res = temp = strtol(cp, &end, base);
372 
373 	/* skip newline character, if any */
374 	if (*end == '\n')
375 		end++;
376 	if (*cp == 0 || *end != 0)
377 		return (-EINVAL);
378 	if (temp != (int)temp)
379 		return (-ERANGE);
380 	return (0);
381 }
382 
383 static inline int
384 kstrtouint(const char *cp, unsigned int base, unsigned int *res)
385 {
386 	char *end;
387 	unsigned long temp;
388 
389 	*res = temp = strtoul(cp, &end, base);
390 
391 	/* skip newline character, if any */
392 	if (*end == '\n')
393 		end++;
394 	if (*cp == 0 || *end != 0)
395 		return (-EINVAL);
396 	if (temp != (unsigned int)temp)
397 		return (-ERANGE);
398 	return (0);
399 }
400 
401 static inline int
402 kstrtou8(const char *cp, unsigned int base, u8 *res)
403 {
404 	char *end;
405 	unsigned long temp;
406 
407 	*res = temp = strtoul(cp, &end, base);
408 
409 	/* skip newline character, if any */
410 	if (*end == '\n')
411 		end++;
412 	if (*cp == 0 || *end != 0)
413 		return (-EINVAL);
414 	if (temp != (u8)temp)
415 		return (-ERANGE);
416 	return (0);
417 }
418 
419 static inline int
420 kstrtou16(const char *cp, unsigned int base, u16 *res)
421 {
422 	char *end;
423 	unsigned long temp;
424 
425 	*res = temp = strtoul(cp, &end, base);
426 
427 	/* skip newline character, if any */
428 	if (*end == '\n')
429 		end++;
430 	if (*cp == 0 || *end != 0)
431 		return (-EINVAL);
432 	if (temp != (u16)temp)
433 		return (-ERANGE);
434 	return (0);
435 }
436 
437 static inline int
438 kstrtou32(const char *cp, unsigned int base, u32 *res)
439 {
440 	char *end;
441 	unsigned long temp;
442 
443 	*res = temp = strtoul(cp, &end, base);
444 
445 	/* skip newline character, if any */
446 	if (*end == '\n')
447 		end++;
448 	if (*cp == 0 || *end != 0)
449 		return (-EINVAL);
450 	if (temp != (u32)temp)
451 		return (-ERANGE);
452 	return (0);
453 }
454 
455 static inline int
456 kstrtou64(const char *cp, unsigned int base, u64 *res)
457 {
458        char *end;
459 
460        *res = strtouq(cp, &end, base);
461 
462        /* skip newline character, if any */
463        if (*end == '\n')
464                end++;
465        if (*cp == 0 || *end != 0)
466                return (-EINVAL);
467        return (0);
468 }
469 
470 static inline int
471 kstrtoull(const char *cp, unsigned int base, unsigned long long *res)
472 {
473 	return (kstrtou64(cp, base, (u64 *)res));
474 }
475 
476 static inline int
477 kstrtobool(const char *s, bool *res)
478 {
479 	int len;
480 
481 	if (s == NULL || (len = strlen(s)) == 0 || res == NULL)
482 		return (-EINVAL);
483 
484 	/* skip newline character, if any */
485 	if (s[len - 1] == '\n')
486 		len--;
487 
488 	if (len == 1 && strchr("yY1", s[0]) != NULL)
489 		*res = true;
490 	else if (len == 1 && strchr("nN0", s[0]) != NULL)
491 		*res = false;
492 	else if (strncasecmp("on", s, len) == 0)
493 		*res = true;
494 	else if (strncasecmp("off", s, len) == 0)
495 		*res = false;
496 	else
497 		return (-EINVAL);
498 
499 	return (0);
500 }
501 
502 static inline int
503 kstrtobool_from_user(const char __user *s, size_t count, bool *res)
504 {
505 	char buf[8] = {};
506 
507 	if (count > (sizeof(buf) - 1))
508 		count = (sizeof(buf) - 1);
509 
510 	if (copy_from_user(buf, s, count))
511 		return (-EFAULT);
512 
513 	return (kstrtobool(buf, res));
514 }
515 
516 static inline int
517 kstrtoint_from_user(const char __user *s, size_t count, unsigned int base,
518     int *p)
519 {
520 	char buf[36] = {};
521 
522 	if (count > (sizeof(buf) - 1))
523 		count = (sizeof(buf) - 1);
524 
525 	if (copy_from_user(buf, s, count))
526 		return (-EFAULT);
527 
528 	return (kstrtoint(buf, base, p));
529 }
530 
531 static inline int
532 kstrtouint_from_user(const char __user *s, size_t count, unsigned int base,
533     int *p)
534 {
535 	char buf[36] = {};
536 
537 	if (count > (sizeof(buf) - 1))
538 		count = (sizeof(buf) - 1);
539 
540 	if (copy_from_user(buf, s, count))
541 		return (-EFAULT);
542 
543 	return (kstrtouint(buf, base, p));
544 }
545 
546 static inline int
547 kstrtou8_from_user(const char __user *s, size_t count, unsigned int base,
548     u8 *p)
549 {
550 	char buf[8] = {};
551 
552 	if (count > (sizeof(buf) - 1))
553 		count = (sizeof(buf) - 1);
554 
555 	if (copy_from_user(buf, s, count))
556 		return (-EFAULT);
557 
558 	return (kstrtou8(buf, base, p));
559 }
560 
561 #define min(x, y)	((x) < (y) ? (x) : (y))
562 #define max(x, y)	((x) > (y) ? (x) : (y))
563 
564 #define min3(a, b, c)	min(a, min(b,c))
565 #define max3(a, b, c)	max(a, max(b,c))
566 
567 #define	min_t(type, x, y) ({			\
568 	type __min1 = (x);			\
569 	type __min2 = (y);			\
570 	__min1 < __min2 ? __min1 : __min2; })
571 
572 #define	max_t(type, x, y) ({			\
573 	type __max1 = (x);			\
574 	type __max2 = (y);			\
575 	__max1 > __max2 ? __max1 : __max2; })
576 
577 #define offsetofend(t, m)	\
578         (offsetof(t, m) + sizeof((((t *)0)->m)))
579 
580 #define clamp_t(type, _x, min, max)	min_t(type, max_t(type, _x, min), max)
581 #define clamp(x, lo, hi)		min( max(x,lo), hi)
582 #define	clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
583 
584 /*
585  * This looks more complex than it should be. But we need to
586  * get the type for the ~ right in round_down (it needs to be
587  * as wide as the result!), and we want to evaluate the macro
588  * arguments just once each.
589  */
590 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
591 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
592 #define round_down(x, y) ((x) & ~__round_mask(x, y))
593 
594 #define	smp_processor_id()	PCPU_GET(cpuid)
595 #define	num_possible_cpus()	mp_ncpus
596 #define	num_online_cpus()	mp_ncpus
597 
598 #if defined(__i386__) || defined(__amd64__)
599 extern bool linux_cpu_has_clflush;
600 #define	cpu_has_clflush		linux_cpu_has_clflush
601 #endif
602 
603 /* Swap values of a and b */
604 #define swap(a, b) do {			\
605 	typeof(a) _swap_tmp = a;	\
606 	a = b;				\
607 	b = _swap_tmp;			\
608 } while (0)
609 
610 #define	DIV_ROUND_CLOSEST(x, divisor)	(((x) + ((divisor) / 2)) / (divisor))
611 
612 #define	DIV_ROUND_CLOSEST_ULL(x, divisor) ({		\
613 	__typeof(divisor) __d = (divisor);		\
614 	unsigned long long __ret = (x) + (__d) / 2;	\
615 	__ret /= __d;					\
616 	__ret;						\
617 })
618 
619 static inline uintmax_t
620 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor)
621 {
622 	uintmax_t q = (x / divisor);
623 	uintmax_t r = (x % divisor);
624 
625 	return ((q * multiplier) + ((r * multiplier) / divisor));
626 }
627 
628 static inline int64_t
629 abs64(int64_t x)
630 {
631 	return (x < 0 ? -x : x);
632 }
633 
634 typedef struct linux_ratelimit {
635 	struct timeval lasttime;
636 	int counter;
637 } linux_ratelimit_t;
638 
639 static inline bool
640 linux_ratelimited(linux_ratelimit_t *rl)
641 {
642 	return (ppsratecheck(&rl->lasttime, &rl->counter, 1));
643 }
644 
645 #define	struct_size(ptr, field, num) ({ \
646 	const size_t __size = offsetof(__typeof(*(ptr)), field); \
647 	const size_t __max = (SIZE_MAX - __size) / sizeof((ptr)->field[0]); \
648 	((num) > __max) ? SIZE_MAX : (__size + sizeof((ptr)->field[0]) * (num)); \
649 })
650 
651 #define	__is_constexpr(x) \
652 	__builtin_constant_p(x)
653 
654 /*
655  * The is_signed() macro below returns true if the passed data type is
656  * signed. Else false is returned.
657  */
658 #define	is_signed(datatype) (((datatype)-1 / (datatype)2) == (datatype)0)
659 
660 /*
661  * The type_max() macro below returns the maxium positive value the
662  * passed data type can hold.
663  */
664 #define	type_max(datatype) ( \
665   (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MAX : UINT64_MAX) : \
666   (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MAX : UINT32_MAX) : \
667   (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MAX : UINT16_MAX) : \
668 			    (is_signed(datatype) ? INT8_MAX : UINT8_MAX) \
669 )
670 
671 /*
672  * The type_min() macro below returns the minimum value the passed
673  * data type can hold. For unsigned types the minimum value is always
674  * zero. For signed types it may vary.
675  */
676 #define	type_min(datatype) ( \
677   (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MIN : 0) : \
678   (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MIN : 0) : \
679   (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MIN : 0) : \
680 			    (is_signed(datatype) ? INT8_MIN : 0) \
681 )
682 
683 #define	TAINT_WARN	0
684 #define	test_taint(x)	(0)
685 #define	add_taint(x,y)	do {	\
686 	} while (0)
687 
688 static inline int
689 _h2b(const char c)
690 {
691 
692 	if (c >= '0' && c <= '9')
693 		return (c - '0');
694 	if (c >= 'a' && c <= 'f')
695 		return (10 + c - 'a');
696 	if (c >= 'A' && c <= 'F')
697 		return (10 + c - 'A');
698 	return (-EINVAL);
699 }
700 
701 static inline int
702 hex2bin(uint8_t *bindst, const char *hexsrc, size_t binlen)
703 {
704 	int hi4, lo4;
705 
706 	while (binlen > 0) {
707 		hi4 = _h2b(*hexsrc++);
708 		lo4 = _h2b(*hexsrc++);
709 		if (hi4 < 0 || lo4 < 0)
710 			return (-EINVAL);
711 
712 		*bindst++ = (hi4 << 4) | lo4;
713 		binlen--;
714 	}
715 
716 	return (0);
717 }
718 
719 #define	DECLARE_FLEX_ARRAY(_t, _n)					\
720     struct { struct { } __dummy_ ## _n; _t _n[0]; }
721 
722 /*
723  * Checking if an option is defined would be easy if we could do CPP inside CPP.
724  * The defined case whether -Dxxx or -Dxxx=1 are easy to deal with.  In either
725  * case the defined value is "1". A more general -Dxxx=<c> case will require
726  * more effort to deal with all possible "true" values. Hope we do not have
727  * to do this as well.
728  * The real problem is the undefined case.  To avoid this problem we do the
729  * concat/varargs trick: "yyy" ## xxx can make two arguments if xxx is "1"
730  * by having a #define for yyy_1 which is "ignore,".
731  * Otherwise we will just get "yyy".
732  * Need to be careful about variable substitutions in macros though.
733  * This way we make a (true, false) problem a (don't care, true, false) or a
734  * (don't care true, false).  Then we can use a variadic macro to only select
735  * the always well known and defined argument #2.  And that seems to be
736  * exactly what we need.  Use 1 for true and 0 for false to also allow
737  * #if IS_*() checks pre-compiler checks which do not like #if true.
738  */
739 #define ___XAB_1		dontcare,
740 #define ___IS_XAB(_ignore, _x, ...)	(_x)
741 #define	__IS_XAB(_x)		___IS_XAB(_x 1, 0)
742 #define	_IS_XAB(_x)		__IS_XAB(__CONCAT(___XAB_, _x))
743 
744 /* This is if CONFIG_ccc=y. */
745 #define	IS_BUILTIN(_x)		_IS_XAB(_x)
746 /* This is if CONFIG_ccc=m. */
747 #define	IS_MODULE(_x)		_IS_XAB(_x ## _MODULE)
748 /* This is if CONFIG_ccc is compiled in(=y) or a module(=m). */
749 #define	IS_ENABLED(_x)		(IS_BUILTIN(_x) || IS_MODULE(_x))
750 /*
751  * This is weird case.  If the CONFIG_ccc is builtin (=y) this returns true;
752  * or if the CONFIG_ccc is a module (=m) and the caller is built as a module
753  * (-DMODULE defined) this returns true, but if the callers is not a module
754  * (-DMODULE not defined, which means caller is BUILTIN) then it returns
755  * false.  In other words, a module can reach the kernel, a module can reach
756  * a module, but the kernel cannot reach a module, and code never compiled
757  * cannot be reached either.
758  * XXX -- I'd hope the module-to-module case would be handled by a proper
759  * module dependency definition (MODULE_DEPEND() in FreeBSD).
760  */
761 #define	IS_REACHABLE(_x)	(IS_BUILTIN(_x) || \
762 				    (IS_MODULE(_x) && IS_BUILTIN(MODULE)))
763 
764 #endif	/* _LINUXKPI_LINUX_KERNEL_H_ */
765