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Will Deacon
8bd9cb51da
In preparation for implementing the asm-generic atomic bitops in terms of atomic_long_*(), we need to prevent <asm/atomic.h> implementations from pulling in <linux/bitops.h>. A common reason for this include is for the BITS_PER_BYTE definition, so move this and some other BIT() and masking macros into a new header file, <linux/bits.h>. Signed-off-by: Will Deacon <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lore.kernel.org/lkml/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
27 lines
833 B
C
27 lines
833 B
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 <asm/bitsperlong.h>
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#define BIT(nr) (1UL << (nr))
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#define BIT_ULL(nr) (1ULL << (nr))
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#define BIT_MASK(nr) (1UL << ((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) (1ULL << ((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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#define GENMASK(h, l) \
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(((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
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#define GENMASK_ULL(h, l) \
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(((~0ULL) - (1ULL << (l)) + 1) & \
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(~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
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#endif /* __LINUX_BITS_H */
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