55 lines
1.6 KiB
C
55 lines
1.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LINUX_BITS_H
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#define __LINUX_BITS_H
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#include <linux/const.h>
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#include <vdso/bits.h>
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#include <uapi/linux/bits.h>
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#include <asm/bitsperlong.h>
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#define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG))
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#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
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#define BIT_ULL_MASK(nr) (ULL(1) << ((nr) % BITS_PER_LONG_LONG))
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#define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
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#define BITS_PER_BYTE 8
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/*
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* Create a contiguous bitmask starting at bit position @l and ending at
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* position @h. For example
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* GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
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*/
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#if !defined(__ASSEMBLY__)
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#include <linux/build_bug.h>
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#define GENMASK_INPUT_CHECK(h, l) \
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(BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
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__is_constexpr((l) > (h)), (l) > (h), 0)))
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#else
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/*
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* BUILD_BUG_ON_ZERO is not available in h files included from asm files,
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* disable the input check if that is the case.
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*/
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#define GENMASK_INPUT_CHECK(h, l) 0
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#endif
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#define GENMASK(h, l) \
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(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
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#define GENMASK_ULL(h, l) \
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(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
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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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* __GENMASK_U128() depends on _BIT128() which would not work
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* in the asm code, as it shifts an 'unsigned __init128' data
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* type instead of direct representation of 128 bit constants
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* such as long and unsigned long. The fundamental problem is
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* that a 128 bit constant will get silently truncated by the
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* gcc compiler.
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*/
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#define GENMASK_U128(h, l) \
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(GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l))
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#endif
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#endif /* __LINUX_BITS_H */
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