Commit de9e2b3d authored by Cristian Ciocaltea's avatar Cristian Ciocaltea Committed by Daniel Stone
Browse files

uapi: Provide DIV_ROUND_CLOSEST() 



Currently DIV_ROUND_CLOSEST() is only available for the kernel via
include/linux/math.h.

Expose it to userland as well by adding __KERNEL_DIV_ROUND_CLOSEST() as
a common definition in uapi.

Additionally, ensure it allows building ISO C applications by switching
from the 'typeof' GNU extension to the ISO-friendly __typeof__.

Reviewed-by: default avatarNícolas F. R. A. Prado <nfraprado@collabora.com>
Tested-by: default avatarDiederik de Haas <diederik@cknow-tech.com>
Acked-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: default avatarCristian Ciocaltea <cristian.ciocaltea@collabora.com>
Link: https://patch.msgid.link/20260303-rk3588-bgcolor-v8-1-fee377037ad1@collabora.com


Signed-off-by: default avatarDaniel Stone <daniels@collabora.com>
parent 25854131

include/linux/math.h

+1 −17
Original line number Diff line number Diff line
@@ -89,23 +89,7 @@ 
}							\

)



/*

 * Divide positive or negative dividend by positive or negative divisor

 * and round to closest integer. Result is undefined for negative

 * divisors if the dividend variable type is unsigned and for negative

 * dividends if the divisor variable type is unsigned.

 */

#define DIV_ROUND_CLOSEST(x, divisor)(			\

{							\

	typeof(x) __x = x;				\

	typeof(divisor) __d = divisor;			\

	(((typeof(x))-1) > 0 ||				\

	 ((typeof(divisor))-1) > 0 ||			\

	 (((__x) > 0) == ((__d) > 0))) ?		\

		(((__x) + ((__d) / 2)) / (__d)) :	\

		(((__x) - ((__d) / 2)) / (__d));	\

}							\

)

#define DIV_ROUND_CLOSEST __KERNEL_DIV_ROUND_CLOSEST

/*

 * Same as above but for u64 dividends. divisor must be a 32-bit

 * number.

include/uapi/linux/const.h

+18 −0
Original line number Diff line number Diff line
@@ -50,4 +50,22 @@ 


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



/*

 * Divide positive or negative dividend by positive or negative divisor

 * and round to closest integer. Result is undefined for negative

 * divisors if the dividend variable type is unsigned and for negative

 * dividends if the divisor variable type is unsigned.

 */

#define __KERNEL_DIV_ROUND_CLOSEST(x, divisor)		\

({							\

	__typeof__(x) __x = x;				\

	__typeof__(divisor) __d = divisor;		\

							\

	(((__typeof__(x))-1) > 0 ||			\

	 ((__typeof__(divisor))-1) > 0 ||		\

	 (((__x) > 0) == ((__d) > 0))) ?		\

		(((__x) + ((__d) / 2)) / (__d)) :	\

		(((__x) - ((__d) / 2)) / (__d));	\

})



#endif /* _UAPI_LINUX_CONST_H */