122 lines
3.2 KiB
C
122 lines
3.2 KiB
C
#ifndef _LINUX_KERNEL_H
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#define _LINUX_KERNEL_H
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#include <linux/compiler.h>
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#include <linux/barebox-wrapper.h>
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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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#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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* clamp - return a value clamped to a given range with strict typechecking
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* @val: current value
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* @min: minimum allowable value
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* @max: maximum allowable value
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*
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* This macro does strict typechecking of min/max 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, min, max) ({ \
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typeof(val) __val = (val); \
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typeof(min) __min = (min); \
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typeof(max) __max = (max); \
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(void) (&__val == &__min); \
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(void) (&__val == &__max); \
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__val = __val < __min ? __min: __val; \
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__val > __max ? __max: __val; })
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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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#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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* 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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* @min: minimum allowable value
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* @max: 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, min, max) ({ \
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type __val = (val); \
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type __min = (min); \
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type __max = (max); \
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__val = __val < __min ? __min: __val; \
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__val > __max ? __max: __val; })
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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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* @min: minimum allowable value
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* @max: 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, min, max) ({ \
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typeof(val) __val = (val); \
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typeof(val) __min = (min); \
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typeof(val) __max = (max); \
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__val = __val < __min ? __min: __val; \
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__val > __max ? __max: __val; })
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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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* 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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#endif /* _LINUX_KERNEL_H */
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