include/linux/bitops.h - third_party/kernel - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_BITOPS_H
 #define _LINUX_BITOPS_H

 #include <asm/types.h>
 #include <linux/bits.h>
 #include <linux/typecheck.h>

 #include <uapi/linux/kernel.h>

 /* Set bits in the first 'n' bytes when loaded from memory */
 #ifdef __LITTLE_ENDIAN
 #  define aligned_byte_mask(n) ((1UL << 8*(n))-1)
 #else
 #  define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
 #endif

 #define BITS_PER_TYPE(type)	(sizeof(type) * BITS_PER_BYTE)
 #define BITS_TO_LONGS(nr)	__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
 #define BITS_TO_U64(nr)		__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
 #define BITS_TO_U32(nr)		__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
 #define BITS_TO_BYTES(nr)	__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))

 extern unsigned int __sw_hweight8(unsigned int w);
 extern unsigned int __sw_hweight16(unsigned int w);
 extern unsigned int __sw_hweight32(unsigned int w);
 extern unsigned long __sw_hweight64(__u64 w);

 /*
  * Include this here because some architectures need generic_ffs/fls in
  * scope
  */
 #include <asm/bitops.h>

 #define for_each_set_bit(bit, addr, size) \
 	for ((bit) = find_first_bit((addr), (size));		\
 	     (bit) < (size);					\
 	     (bit) = find_next_bit((addr), (size), (bit) + 1))

 /* same as for_each_set_bit() but use bit as value to start with */
 #define for_each_set_bit_from(bit, addr, size) \
 	for ((bit) = find_next_bit((addr), (size), (bit));	\
 	     (bit) < (size);					\
 	     (bit) = find_next_bit((addr), (size), (bit) + 1))

 #define for_each_clear_bit(bit, addr, size) \
 	for ((bit) = find_first_zero_bit((addr), (size));	\
 	     (bit) < (size);					\
 	     (bit) = find_next_zero_bit((addr), (size), (bit) + 1))

 /* same as for_each_clear_bit() but use bit as value to start with */
 #define for_each_clear_bit_from(bit, addr, size) \
 	for ((bit) = find_next_zero_bit((addr), (size), (bit));	\
 	     (bit) < (size);					\
 	     (bit) = find_next_zero_bit((addr), (size), (bit) + 1))

 /**
  * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
  * @start: bit offset to start search and to store the current iteration offset
  * @clump: location to store copy of current 8-bit clump
  * @bits: bitmap address to base the search on
  * @size: bitmap size in number of bits
  */
 #define for_each_set_clump8(start, clump, bits, size) \
 	for ((start) = find_first_clump8(&(clump), (bits), (size)); \
 	     (start) < (size); \
 	     (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))

 static inline int get_bitmask_order(unsigned int count)
 {
 	int order;

 	order = fls(count);
 	return order;	/* We could be slightly more clever with -1 here... */
 }

 static __always_inline unsigned long hweight_long(unsigned long w)
 {
 	return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
 }

 /**
  * rol64 - rotate a 64-bit value left
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u64 rol64(__u64 word, unsigned int shift)
 {
 	return (word << (shift & 63)) | (word >> ((-shift) & 63));
 }

 /**
  * ror64 - rotate a 64-bit value right
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u64 ror64(__u64 word, unsigned int shift)
 {
 	return (word >> (shift & 63)) | (word << ((-shift) & 63));
 }

 /**
  * rol32 - rotate a 32-bit value left
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u32 rol32(__u32 word, unsigned int shift)
 {
 	return (word << (shift & 31)) | (word >> ((-shift) & 31));
 }

 /**
  * ror32 - rotate a 32-bit value right
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u32 ror32(__u32 word, unsigned int shift)
 {
 	return (word >> (shift & 31)) | (word << ((-shift) & 31));
 }

 /**
  * rol16 - rotate a 16-bit value left
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u16 rol16(__u16 word, unsigned int shift)
 {
 	return (word << (shift & 15)) | (word >> ((-shift) & 15));
 }

 /**
  * ror16 - rotate a 16-bit value right
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u16 ror16(__u16 word, unsigned int shift)
 {
 	return (word >> (shift & 15)) | (word << ((-shift) & 15));
 }

 /**
  * rol8 - rotate an 8-bit value left
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u8 rol8(__u8 word, unsigned int shift)
 {
 	return (word << (shift & 7)) | (word >> ((-shift) & 7));
 }

 /**
  * ror8 - rotate an 8-bit value right
  * @word: value to rotate
  * @shift: bits to roll
  */
 static inline __u8 ror8(__u8 word, unsigned int shift)
 {
 	return (word >> (shift & 7)) | (word << ((-shift) & 7));
 }

 /**
  * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
  * @value: value to sign extend
  * @index: 0 based bit index (0<=index<32) to sign bit
  *
  * This is safe to use for 16- and 8-bit types as well.
  */
 static __always_inline __s32 sign_extend32(__u32 value, int index)
 {
 	__u8 shift = 31 - index;
 	return (__s32)(value << shift) >> shift;
 }

 /**
  * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
  * @value: value to sign extend
  * @index: 0 based bit index (0<=index<64) to sign bit
  */
 static __always_inline __s64 sign_extend64(__u64 value, int index)
 {
 	__u8 shift = 63 - index;
 	return (__s64)(value << shift) >> shift;
 }

 static inline unsigned fls_long(unsigned long l)
 {
 	if (sizeof(l) == 4)
 		return fls(l);
 	return fls64(l);
 }

 static inline int get_count_order(unsigned int count)
 {
 	if (count == 0)
 		return -1;

 	return fls(--count);
 }

 /**
  * get_count_order_long - get order after rounding @l up to power of 2
  * @l: parameter
  *
  * it is same as get_count_order() but with long type parameter
  */
 static inline int get_count_order_long(unsigned long l)
 {
 	if (l == 0UL)
 		return -1;
 	return (int)fls_long(--l);
 }

 /**
  * __ffs64 - find first set bit in a 64 bit word
  * @word: The 64 bit word
  *
  * On 64 bit arches this is a synonym for __ffs
  * The result is not defined if no bits are set, so check that @word
  * is non-zero before calling this.
  */
 static inline unsigned long __ffs64(u64 word)
 {
 #if BITS_PER_LONG == 32
 	if (((u32)word) == 0UL)
 		return __ffs((u32)(word >> 32)) + 32;
 #elif BITS_PER_LONG != 64
 #error BITS_PER_LONG not 32 or 64
 #endif
 	return __ffs((unsigned long)word);
 }

 /**
  * assign_bit - Assign value to a bit in memory
  * @nr: the bit to set
  * @addr: the address to start counting from
  * @value: the value to assign
  */
 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
 				       bool value)
 {
 	if (value)
 		set_bit(nr, addr);
 	else
 		clear_bit(nr, addr);
 }

 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
 					 bool value)
 {
 	if (value)
 		__set_bit(nr, addr);
 	else
 		__clear_bit(nr, addr);
 }

 /**
  * __ptr_set_bit - Set bit in a pointer's value
  * @nr: the bit to set
  * @addr: the address of the pointer variable
  *
  * Example:
  *	void *p = foo();
  *	__ptr_set_bit(bit, &p);
  */
 #define __ptr_set_bit(nr, addr)                         \
 	({                                              \
 		typecheck_pointer(*(addr));             \
 		__set_bit(nr, (unsigned long *)(addr)); \
 	})

 /**
  * __ptr_clear_bit - Clear bit in a pointer's value
  * @nr: the bit to clear
  * @addr: the address of the pointer variable
  *
  * Example:
  *	void *p = foo();
  *	__ptr_clear_bit(bit, &p);
  */
 #define __ptr_clear_bit(nr, addr)                         \
 	({                                                \
 		typecheck_pointer(*(addr));               \
 		__clear_bit(nr, (unsigned long *)(addr)); \
 	})

 /**
  * __ptr_test_bit - Test bit in a pointer's value
  * @nr: the bit to test
  * @addr: the address of the pointer variable
  *
  * Example:
  *	void *p = foo();
  *	if (__ptr_test_bit(bit, &p)) {
  *	        ...
  *	} else {
  *		...
  *	}
  */
 #define __ptr_test_bit(nr, addr)                       \
 	({                                             \
 		typecheck_pointer(*(addr));            \
 		test_bit(nr, (unsigned long *)(addr)); \
 	})

 #ifdef __KERNEL__

 #ifndef set_mask_bits
 #define set_mask_bits(ptr, mask, bits)	\
 ({								\
 	const typeof(*(ptr)) mask__ = (mask), bits__ = (bits);	\
 	typeof(*(ptr)) old__, new__;				\
 								\
 	do {							\
 		old__ = READ_ONCE(*(ptr));			\
 		new__ = (old__ & ~mask__) | bits__;		\
 	} while (cmpxchg(ptr, old__, new__) != old__);		\
 								\
 	old__;							\
 })
 #endif

 #ifndef bit_clear_unless
 #define bit_clear_unless(ptr, clear, test)	\
 ({								\
 	const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
 	typeof(*(ptr)) old__, new__;				\
 								\
 	do {							\
 		old__ = READ_ONCE(*(ptr));			\
 		new__ = old__ & ~clear__;			\
 	} while (!(old__ & test__) &&				\
 		 cmpxchg(ptr, old__, new__) != old__);		\
 								\
 	!(old__ & test__);					\
 })
 #endif

 #endif /* __KERNEL__ */
 #endif
	/* SPDX-License-Identifier: GPL-2.0 */
	#ifndef _LINUX_BITOPS_H
	#define _LINUX_BITOPS_H

	#include <asm/types.h>
	#include <linux/bits.h>
	#include <linux/typecheck.h>

	#include <uapi/linux/kernel.h>

	/* Set bits in the first 'n' bytes when loaded from memory */
	#ifdef __LITTLE_ENDIAN
	# define aligned_byte_mask(n) ((1UL << 8*(n))-1)
	#else
	# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
	#endif

	#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
	#define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
	#define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
	#define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
	#define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))

	extern unsigned int __sw_hweight8(unsigned int w);
	extern unsigned int __sw_hweight16(unsigned int w);
	extern unsigned int __sw_hweight32(unsigned int w);
	extern unsigned long __sw_hweight64(__u64 w);

	/*
	* Include this here because some architectures need generic_ffs/fls in
	* scope
	*/
	#include <asm/bitops.h>

	#define for_each_set_bit(bit, addr, size) \
	for ((bit) = find_first_bit((addr), (size)); \
	(bit) < (size); \
	(bit) = find_next_bit((addr), (size), (bit) + 1))

	/* same as for_each_set_bit() but use bit as value to start with */
	#define for_each_set_bit_from(bit, addr, size) \
	for ((bit) = find_next_bit((addr), (size), (bit)); \
	(bit) < (size); \
	(bit) = find_next_bit((addr), (size), (bit) + 1))

	#define for_each_clear_bit(bit, addr, size) \
	for ((bit) = find_first_zero_bit((addr), (size)); \
	(bit) < (size); \
	(bit) = find_next_zero_bit((addr), (size), (bit) + 1))

	/* same as for_each_clear_bit() but use bit as value to start with */
	#define for_each_clear_bit_from(bit, addr, size) \
	for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
	(bit) < (size); \
	(bit) = find_next_zero_bit((addr), (size), (bit) + 1))

	/**
	* for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
	* @start: bit offset to start search and to store the current iteration offset
	* @clump: location to store copy of current 8-bit clump
	* @bits: bitmap address to base the search on
	* @size: bitmap size in number of bits
	*/
	#define for_each_set_clump8(start, clump, bits, size) \
	for ((start) = find_first_clump8(&(clump), (bits), (size)); \
	(start) < (size); \
	(start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))

	static inline int get_bitmask_order(unsigned int count)
	{
	int order;

	order = fls(count);
	return order; /* We could be slightly more clever with -1 here... */
	}

	static __always_inline unsigned long hweight_long(unsigned long w)
	{
	return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
	}

	/**
	* rol64 - rotate a 64-bit value left
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u64 rol64(__u64 word, unsigned int shift)
	{
	return (word << (shift & 63)) \| (word >> ((-shift) & 63));
	}

	/**
	* ror64 - rotate a 64-bit value right
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u64 ror64(__u64 word, unsigned int shift)
	{
	return (word >> (shift & 63)) \| (word << ((-shift) & 63));
	}

	/**
	* rol32 - rotate a 32-bit value left
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u32 rol32(__u32 word, unsigned int shift)
	{
	return (word << (shift & 31)) \| (word >> ((-shift) & 31));
	}

	/**
	* ror32 - rotate a 32-bit value right
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u32 ror32(__u32 word, unsigned int shift)
	{
	return (word >> (shift & 31)) \| (word << ((-shift) & 31));
	}

	/**
	* rol16 - rotate a 16-bit value left
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u16 rol16(__u16 word, unsigned int shift)
	{
	return (word << (shift & 15)) \| (word >> ((-shift) & 15));
	}

	/**
	* ror16 - rotate a 16-bit value right
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u16 ror16(__u16 word, unsigned int shift)
	{
	return (word >> (shift & 15)) \| (word << ((-shift) & 15));
	}

	/**
	* rol8 - rotate an 8-bit value left
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u8 rol8(__u8 word, unsigned int shift)
	{
	return (word << (shift & 7)) \| (word >> ((-shift) & 7));
	}

	/**
	* ror8 - rotate an 8-bit value right
	* @word: value to rotate
	* @shift: bits to roll
	*/
	static inline __u8 ror8(__u8 word, unsigned int shift)
	{
	return (word >> (shift & 7)) \| (word << ((-shift) & 7));
	}

	/**
	* sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
	* @value: value to sign extend
	* @index: 0 based bit index (0<=index<32) to sign bit
	*
	* This is safe to use for 16- and 8-bit types as well.
	*/
	static __always_inline __s32 sign_extend32(__u32 value, int index)
	{
	__u8 shift = 31 - index;
	return (__s32)(value << shift) >> shift;
	}

	/**
	* sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
	* @value: value to sign extend
	* @index: 0 based bit index (0<=index<64) to sign bit
	*/
	static __always_inline __s64 sign_extend64(__u64 value, int index)
	{
	__u8 shift = 63 - index;
	return (__s64)(value << shift) >> shift;
	}

	static inline unsigned fls_long(unsigned long l)
	{
	if (sizeof(l) == 4)
	return fls(l);
	return fls64(l);
	}

	static inline int get_count_order(unsigned int count)
	{
	if (count == 0)
	return -1;

	return fls(--count);
	}

	/**
	* get_count_order_long - get order after rounding @l up to power of 2
	* @l: parameter
	*
	* it is same as get_count_order() but with long type parameter
	*/
	static inline int get_count_order_long(unsigned long l)
	{
	if (l == 0UL)
	return -1;
	return (int)fls_long(--l);
	}

	/**
	* __ffs64 - find first set bit in a 64 bit word
	* @word: The 64 bit word
	*
	* On 64 bit arches this is a synonym for __ffs
	* The result is not defined if no bits are set, so check that @word
	* is non-zero before calling this.
	*/
	static inline unsigned long __ffs64(u64 word)
	{
	#if BITS_PER_LONG == 32
	if (((u32)word) == 0UL)
	return __ffs((u32)(word >> 32)) + 32;
	#elif BITS_PER_LONG != 64
	#error BITS_PER_LONG not 32 or 64
	#endif
	return __ffs((unsigned long)word);
	}

	/**
	* assign_bit - Assign value to a bit in memory
	* @nr: the bit to set
	* @addr: the address to start counting from
	* @value: the value to assign
	*/
	static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
	bool value)
	{
	if (value)
	set_bit(nr, addr);
	else
	clear_bit(nr, addr);
	}

	static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
	bool value)
	{
	if (value)
	__set_bit(nr, addr);
	else
	__clear_bit(nr, addr);
	}

	/**
	* __ptr_set_bit - Set bit in a pointer's value
	* @nr: the bit to set
	* @addr: the address of the pointer variable
	*
	* Example:
	* void *p = foo();
	* __ptr_set_bit(bit, &p);
	*/
	#define __ptr_set_bit(nr, addr) \
	({ \
	typecheck_pointer(*(addr)); \
	__set_bit(nr, (unsigned long *)(addr)); \
	})

	/**
	* __ptr_clear_bit - Clear bit in a pointer's value
	* @nr: the bit to clear
	* @addr: the address of the pointer variable
	*
	* Example:
	* void *p = foo();
	* __ptr_clear_bit(bit, &p);
	*/
	#define __ptr_clear_bit(nr, addr) \
	({ \
	typecheck_pointer(*(addr)); \
	__clear_bit(nr, (unsigned long *)(addr)); \
	})

	/**
	* __ptr_test_bit - Test bit in a pointer's value
	* @nr: the bit to test
	* @addr: the address of the pointer variable
	*
	* Example:
	* void *p = foo();
	* if (__ptr_test_bit(bit, &p)) {
	* ...
	* } else {
	* ...
	* }
	*/
	#define __ptr_test_bit(nr, addr) \
	({ \
	typecheck_pointer(*(addr)); \
	test_bit(nr, (unsigned long *)(addr)); \
	})

	#ifdef __KERNEL__

	#ifndef set_mask_bits
	#define set_mask_bits(ptr, mask, bits) \
	({ \
	const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
	typeof(*(ptr)) old__, new__; \
	\
	do { \
	old__ = READ_ONCE(*(ptr)); \
	new__ = (old__ & ~mask__) \| bits__; \
	} while (cmpxchg(ptr, old__, new__) != old__); \
	\
	old__; \
	})
	#endif

	#ifndef bit_clear_unless
	#define bit_clear_unless(ptr, clear, test) \
	({ \
	const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
	typeof(*(ptr)) old__, new__; \
	\
	do { \
	old__ = READ_ONCE(*(ptr)); \
	new__ = old__ & ~clear__; \
	} while (!(old__ & test__) && \
	cmpxchg(ptr, old__, new__) != old__); \
	\
	!(old__ & test__); \
	})
	#endif

	#endif /* __KERNEL__ */
	#endif