54 lines
1.6 KiB
C
54 lines
1.6 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 __init128' 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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#endif /* _UAPI_LINUX_CONST_H */
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