tools/include/linux/kernel.h

#ifndef __TOOLS_LINUX_KERNEL_H
#define __TOOLS_LINUX_KERNEL_H

#include <stdarg.h>
#include <stddef.h>
#include <assert.h>
#include <linux/compiler.h>
#include <endian.h>
#include <byteswap.h>

#ifndef UINT_MAX
#define UINT_MAX	(~0U)
#endif

#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))

#define PERF_ALIGN(x, a)	__PERF_ALIGN_MASK(x, (typeof(x))(a)-1)
#define __PERF_ALIGN_MASK(x, mask)	(((x)+(mask))&~(mask))

#ifndef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif

#ifndef container_of
/**
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:	the pointer to the member.
 * @type:	the type of the container struct this is embedded in.
 * @member:	the name of the member within the struct.
 *
 */
#define container_of(ptr, type, member) ({			\
	const typeof(((type *)0)->member) * __mptr = (ptr);	\
	(type *)((char *)__mptr - offsetof(type, member)); })
#endif

#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))

#ifndef max
#define max(x, y) ({				\
	typeof(x) _max1 = (x);			\
	typeof(y) _max2 = (y);			\
	(void) (&_max1 == &_max2);		\
	_max1 > _max2 ? _max1 : _max2; })
#endif

#ifndef min
#define min(x, y) ({				\
	typeof(x) _min1 = (x);			\
	typeof(y) _min2 = (y);			\
	(void) (&_min1 == &_min2);		\
	_min1 < _min2 ? _min1 : _min2; })
#endif

#ifndef roundup
#define roundup(x, y) (                                \
{                                                      \
	const typeof(y) __y = y;		       \
	(((x) + (__y - 1)) / __y) * __y;	       \
}                                                      \
)
#endif

#ifndef BUG_ON
#ifdef NDEBUG
#define BUG_ON(cond) do { if (cond) {} } while (0)
#else
#define BUG_ON(cond) assert(!(cond))
#endif
#endif

#if __BYTE_ORDER == __BIG_ENDIAN
#define cpu_to_le16 bswap_16
#define cpu_to_le32 bswap_32
#define cpu_to_le64 bswap_64
#define le16_to_cpu bswap_16
#define le32_to_cpu bswap_32
#define le64_to_cpu bswap_64
#define cpu_to_be16
#define cpu_to_be32
#define cpu_to_be64
#define be16_to_cpu
#define be32_to_cpu
#define be64_to_cpu
#else
#define cpu_to_le16
#define cpu_to_le32
#define cpu_to_le64
#define le16_to_cpu
#define le32_to_cpu
#define le64_to_cpu
#define cpu_to_be16 bswap_16
#define cpu_to_be32 bswap_32
#define cpu_to_be64 bswap_64
#define be16_to_cpu bswap_16
#define be32_to_cpu bswap_32
#define be64_to_cpu bswap_64
#endif

int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
int scnprintf(char * buf, size_t size, const char * fmt, ...);

#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

/*
 * This looks more complex than it should be. But we need to
 * get the type for the ~ right in round_down (it needs to be
 * as wide as the result!), and we want to evaluate the macro
 * arguments just once each.
 */
#define __round_mask(x, y) ((__typeof__(x))((y)-1))
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
#define round_down(x, y) ((x) & ~__round_mask(x, y))

#endif