Commit 8bd9cb51 authored by Will Deacon's avatar Will Deacon Committed by Ingo Molnar
Browse files

locking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux/bits.h> file 



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: default avatarWill Deacon <will.deacon@arm.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: yamada.masahiro@socionext.com
Link: https://lore.kernel.org/lkml/1529412794-17720-4-git-send-email-will.deacon@arm.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 84038fd9

include/linux/bitops.h

+1 −21
Original line number Diff line number Diff line
@@ -2,29 +2,9 @@ 
#ifndef _LINUX_BITOPS_H

#define _LINUX_BITOPS_H

#include <asm/types.h>

#include <linux/bits.h>



#ifdef	__KERNEL__

#define BIT(nr)			(1UL << (nr))

#define BIT_ULL(nr)		(1ULL << (nr))

#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))

#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)

#define BIT_ULL_MASK(nr)	(1ULL << ((nr) % BITS_PER_LONG_LONG))

#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)

#define BITS_PER_BYTE		8

#define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))

#endif



/*

 * Create a contiguous bitmask starting at bit position @l and ending at

 * position @h. For example

 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.

 */

#define GENMASK(h, l) \

	(((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))



#define GENMASK_ULL(h, l) \

	(((~0ULL) - (1ULL << (l)) + 1) & \

	 (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))



extern unsigned int __sw_hweight8(unsigned int w);

extern unsigned int __sw_hweight16(unsigned int w);

include/linux/bits.h

0 → 100644
+26 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __LINUX_BITS_H

#define __LINUX_BITS_H

#include <asm/bitsperlong.h>



#define BIT(nr)			(1UL << (nr))

#define BIT_ULL(nr)		(1ULL << (nr))

#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))

#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)

#define BIT_ULL_MASK(nr)	(1ULL << ((nr) % BITS_PER_LONG_LONG))

#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)

#define BITS_PER_BYTE		8



/*

 * Create a contiguous bitmask starting at bit position @l and ending at

 * position @h. For example

 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.

 */

#define GENMASK(h, l) \

	(((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))



#define GENMASK_ULL(h, l) \

	(((~0ULL) - (1ULL << (l)) + 1) & \

	 (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))



#endif	/* __LINUX_BITS_H */

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