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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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Cristian Ciocaltea
de9e2b3d88
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: Nícolas F. R. A. Prado <nfraprado@collabora.com> Tested-by: Diederik de Haas <diederik@cknow-tech.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Link: https://patch.msgid.link/20260303-rk3588-bgcolor-v8-1-fee377037ad1@collabora.com Signed-off-by: Daniel Stone <daniels@collabora.com>
72 lines
2.1 KiB
C
72 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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/* const.h: Macros for dealing with constants. */
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#ifndef _UAPI_LINUX_CONST_H
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#define _UAPI_LINUX_CONST_H
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/* Some constant macros are used in both assembler and
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* C code. Therefore we cannot annotate them always with
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* 'UL' and other type specifiers unilaterally. We
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* use the following macros to deal with this.
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*
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* Similarly, _AT() will cast an expression with a type in C, but
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* leave it unchanged in asm.
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*/
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#ifdef __ASSEMBLY__
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#define _AC(X,Y) X
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#define _AT(T,X) X
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#else
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#define __AC(X,Y) (X##Y)
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#define _AC(X,Y) __AC(X,Y)
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#define _AT(T,X) ((T)(X))
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#endif
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#define _UL(x) (_AC(x, UL))
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#define _ULL(x) (_AC(x, ULL))
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#define _BITUL(x) (_UL(1) << (x))
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#define _BITULL(x) (_ULL(1) << (x))
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#if !defined(__ASSEMBLY__)
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/*
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* Missing asm support
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*
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* __BIT128() would not work in the asm code, as it shifts an
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* 'unsigned __int128' data type as direct representation of
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* 128 bit constants is not supported in the gcc compiler, as
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* they get silently truncated.
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*
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* TODO: Please revisit this implementation when gcc compiler
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* starts representing 128 bit constants directly like long
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* and unsigned long etc. Subsequently drop the comment for
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* GENMASK_U128() which would then start supporting asm code.
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*/
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#define _BIT128(x) ((unsigned __int128)(1) << (x))
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#endif
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#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1)
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#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
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#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
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/*
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* Divide positive or negative dividend by positive or negative divisor
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* and round to closest integer. Result is undefined for negative
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* divisors if the dividend variable type is unsigned and for negative
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* dividends if the divisor variable type is unsigned.
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*/
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#define __KERNEL_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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\
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(((__typeof__(x))-1) > 0 || \
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((__typeof__(divisor))-1) > 0 || \
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(((__x) > 0) == ((__d) > 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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#endif /* _UAPI_LINUX_CONST_H */
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