248 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			248 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
| #ifndef _LINUX_KERNEL_H
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| #define _LINUX_KERNEL_H
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| 
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| 
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| #include <linux/types.h>
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| 
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| #define USHRT_MAX	((u16)(~0U))
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| #define SHRT_MAX	((s16)(USHRT_MAX>>1))
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| #define SHRT_MIN	((s16)(-SHRT_MAX - 1))
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| #define INT_MAX		((int)(~0U>>1))
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| #define INT_MIN		(-INT_MAX - 1)
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| #define UINT_MAX	(~0U)
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| #define LONG_MAX	((long)(~0UL>>1))
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| #define LONG_MIN	(-LONG_MAX - 1)
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| #define ULONG_MAX	(~0UL)
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| #define LLONG_MAX	((long long)(~0ULL>>1))
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| #define LLONG_MIN	(-LLONG_MAX - 1)
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| #define ULLONG_MAX	(~0ULL)
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| #ifndef SIZE_MAX
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| #define SIZE_MAX	(~(size_t)0)
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| #endif
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| 
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| #define U8_MAX		((u8)~0U)
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| #define S8_MAX		((s8)(U8_MAX>>1))
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| #define S8_MIN		((s8)(-S8_MAX - 1))
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| #define U16_MAX		((u16)~0U)
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| #define S16_MAX		((s16)(U16_MAX>>1))
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| #define S16_MIN		((s16)(-S16_MAX - 1))
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| #define U32_MAX		((u32)~0U)
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| #define S32_MAX		((s32)(U32_MAX>>1))
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| #define S32_MIN		((s32)(-S32_MAX - 1))
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| #define U64_MAX		((u64)~0ULL)
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| #define S64_MAX		((s64)(U64_MAX>>1))
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| #define S64_MIN		((s64)(-S64_MAX - 1))
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| 
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| #define STACK_MAGIC	0xdeadbeef
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| 
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| #define REPEAT_BYTE(x)	((~0ul / 0xff) * (x))
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| 
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| #define ALIGN(x,a)		__ALIGN_MASK((x),(typeof(x))(a)-1)
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| #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
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| #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
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| #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
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| 
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| #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
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| 
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| /*
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|  * This looks more complex than it should be. But we need to
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|  * get the type for the ~ right in round_down (it needs to be
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|  * as wide as the result!), and we want to evaluate the macro
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|  * arguments just once each.
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|  */
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| #define __round_mask(x, y) ((__typeof__(x))((y)-1))
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| #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
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| #define round_down(x, y) ((x) & ~__round_mask(x, y))
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| 
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| #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
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| #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
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| 
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| #if BITS_PER_LONG == 32
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| # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
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| #else
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| # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
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| #endif
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| 
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| /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
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| #define roundup(x, y) (					\
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| {							\
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| 	const typeof(y) __y = y;			\
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| 	(((x) + (__y - 1)) / __y) * __y;		\
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| }							\
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| )
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| #define rounddown(x, y) (				\
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| {							\
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| 	typeof(x) __x = (x);				\
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| 	__x - (__x % (y));				\
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| }							\
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| )
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| 
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| /*
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|  * Divide positive or negative dividend by positive divisor and round
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|  * to closest integer. Result is undefined for negative divisors and
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|  * for negative dividends if the divisor variable type is unsigned.
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|  */
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| #define DIV_ROUND_CLOSEST(x, divisor)(			\
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| {							\
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| 	typeof(x) __x = x;				\
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| 	typeof(divisor) __d = divisor;			\
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| 	(((typeof(x))-1) > 0 ||				\
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| 	 ((typeof(divisor))-1) > 0 || (__x) > 0) ?	\
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| 		(((__x) + ((__d) / 2)) / (__d)) :	\
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| 		(((__x) - ((__d) / 2)) / (__d));	\
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| }							\
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| )
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| 
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| /*
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|  * Multiplies an integer by a fraction, while avoiding unnecessary
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|  * overflow or loss of precision.
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|  */
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| #define mult_frac(x, numer, denom)(			\
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| {							\
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| 	typeof(x) quot = (x) / (denom);			\
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| 	typeof(x) rem  = (x) % (denom);			\
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| 	(quot * (numer)) + ((rem * (numer)) / (denom));	\
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| }							\
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| )
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| 
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| /**
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|  * upper_32_bits - return bits 32-63 of a number
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|  * @n: the number we're accessing
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|  *
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|  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
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|  * the "right shift count >= width of type" warning when that quantity is
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|  * 32-bits.
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|  */
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| #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
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| 
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| /**
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|  * lower_32_bits - return bits 0-31 of a number
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|  * @n: the number we're accessing
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|  */
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| #define lower_32_bits(n) ((u32)(n))
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| 
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| /*
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|  * abs() handles unsigned and signed longs, ints, shorts and chars.  For all
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|  * input types abs() returns a signed long.
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|  * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
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|  * for those.
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|  */
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| #define abs(x) ({						\
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| 		long ret;					\
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| 		if (sizeof(x) == sizeof(long)) {		\
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| 			long __x = (x);				\
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| 			ret = (__x < 0) ? -__x : __x;		\
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| 		} else {					\
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| 			int __x = (x);				\
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| 			ret = (__x < 0) ? -__x : __x;		\
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| 		}						\
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| 		ret;						\
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| 	})
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| 
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| #define abs64(x) ({				\
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| 		s64 __x = (x);			\
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| 		(__x < 0) ? -__x : __x;		\
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| 	})
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| 
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| /*
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|  * min()/max()/clamp() macros that also do
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|  * strict type-checking.. See the
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|  * "unnecessary" pointer comparison.
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|  */
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| #define min(x, y) ({				\
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| 	typeof(x) _min1 = (x);			\
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| 	typeof(y) _min2 = (y);			\
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| 	(void) (&_min1 == &_min2);		\
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| 	_min1 < _min2 ? _min1 : _min2; })
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| 
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| #define max(x, y) ({				\
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| 	typeof(x) _max1 = (x);			\
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| 	typeof(y) _max2 = (y);			\
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| 	(void) (&_max1 == &_max2);		\
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| 	_max1 > _max2 ? _max1 : _max2; })
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| 
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| #define min3(x, y, z) min((typeof(x))min(x, y), z)
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| #define max3(x, y, z) max((typeof(x))max(x, y), z)
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| 
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| /**
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|  * min_not_zero - return the minimum that is _not_ zero, unless both are zero
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|  * @x: value1
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|  * @y: value2
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|  */
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| #define min_not_zero(x, y) ({			\
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| 	typeof(x) __x = (x);			\
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| 	typeof(y) __y = (y);			\
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| 	__x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
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| 
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| /**
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|  * clamp - return a value clamped to a given range with strict typechecking
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|  * @val: current value
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|  * @lo: lowest allowable value
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|  * @hi: highest allowable value
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|  *
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|  * This macro does strict typechecking of lo/hi to make sure they are of the
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|  * same type as val.  See the unnecessary pointer comparisons.
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|  */
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| #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
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| 
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| /*
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|  * ..and if you can't take the strict
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|  * types, you can specify one yourself.
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|  *
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|  * Or not use min/max/clamp at all, of course.
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|  */
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| #define min_t(type, x, y) ({			\
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| 	type __min1 = (x);			\
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| 	type __min2 = (y);			\
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| 	__min1 < __min2 ? __min1: __min2; })
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| 
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| #define max_t(type, x, y) ({			\
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| 	type __max1 = (x);			\
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| 	type __max2 = (y);			\
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| 	__max1 > __max2 ? __max1: __max2; })
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| 
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| /**
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|  * clamp_t - return a value clamped to a given range using a given type
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|  * @type: the type of variable to use
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|  * @val: current value
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|  * @lo: minimum allowable value
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|  * @hi: maximum allowable value
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|  *
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|  * This macro does no typechecking and uses temporary variables of type
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|  * 'type' to make all the comparisons.
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|  */
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| #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
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| 
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| /**
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|  * clamp_val - return a value clamped to a given range using val's type
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|  * @val: current value
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|  * @lo: minimum allowable value
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|  * @hi: maximum allowable value
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|  *
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|  * This macro does no typechecking and uses temporary variables of whatever
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|  * type the input argument 'val' is.  This is useful when val is an unsigned
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|  * type and min and max are literals that will otherwise be assigned a signed
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|  * integer type.
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|  */
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| #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
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| 
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| 
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| /*
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|  * swap - swap value of @a and @b
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|  */
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| #define swap(a, b) \
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| 	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
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| 
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| /**
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|  * container_of - cast a member of a structure out to the containing structure
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|  * @ptr:	the pointer to the member.
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|  * @type:	the type of the container struct this is embedded in.
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|  * @member:	the name of the member within the struct.
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|  *
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|  */
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| #define container_of(ptr, type, member) ({			\
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| 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
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| 	(type *)( (char *)__mptr - offsetof(type,member) );})
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| 
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| #endif
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