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- /* 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);
- /*
- * Defined here because those may be needed by architecture-specific static
- * inlines.
- */
- #include <asm-generic/bitops/generic-non-atomic.h>
- /*
- * Many architecture-specific non-atomic bitops contain inline asm code and due
- * to that the compiler can't optimize them to compile-time expressions or
- * constants. In contrary, generic_*() helpers are defined in pure C and
- * compilers optimize them just well.
- * Therefore, to make `unsigned long foo = 0; __set_bit(BAR, &foo)` effectively
- * equal to `unsigned long foo = BIT(BAR)`, pick the generic C alternative when
- * the arguments can be resolved at compile time. That expression itself is a
- * constant and doesn't bring any functional changes to the rest of cases.
- * The casts to `uintptr_t` are needed to mitigate `-Waddress` warnings when
- * passing a bitmap from .bss or .data (-> `!!addr` is always true).
- */
- #define bitop(op, nr, addr) \
- ((__builtin_constant_p(nr) && \
- __builtin_constant_p((uintptr_t)(addr) != (uintptr_t)NULL) && \
- (uintptr_t)(addr) != (uintptr_t)NULL && \
- __builtin_constant_p(*(const unsigned long *)(addr))) ? \
- const##op(nr, addr) : op(nr, addr))
- #define __set_bit(nr, addr) bitop(___set_bit, nr, addr)
- #define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr)
- #define __change_bit(nr, addr) bitop(___change_bit, nr, addr)
- #define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr)
- #define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr)
- #define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr)
- #define test_bit(nr, addr) bitop(_test_bit, nr, addr)
- #define test_bit_acquire(nr, addr) bitop(_test_bit_acquire, nr, addr)
- /*
- * Include this here because some architectures need generic_ffs/fls in
- * scope
- */
- #include <asm/bitops.h>
- /* Check that the bitops prototypes are sane */
- #define __check_bitop_pr(name) \
- static_assert(__same_type(arch_##name, generic_##name) && \
- __same_type(const_##name, generic_##name) && \
- __same_type(_##name, generic_##name))
- __check_bitop_pr(__set_bit);
- __check_bitop_pr(__clear_bit);
- __check_bitop_pr(__change_bit);
- __check_bitop_pr(__test_and_set_bit);
- __check_bitop_pr(__test_and_clear_bit);
- __check_bitop_pr(__test_and_change_bit);
- __check_bitop_pr(test_bit);
- #undef __check_bitop_pr
- 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);
- }
- /**
- * fns - find N'th set bit in a word
- * @word: The word to search
- * @n: Bit to find
- */
- static inline unsigned long fns(unsigned long word, unsigned int n)
- {
- unsigned int bit;
- while (word) {
- bit = __ffs(word);
- if (n-- == 0)
- return bit;
- __clear_bit(bit, &word);
- }
- return BITS_PER_LONG;
- }
- /**
- * 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__; \
- \
- old__ = READ_ONCE(*(ptr)); \
- do { \
- new__ = (old__ & ~mask__) | bits__; \
- } while (!try_cmpxchg(ptr, &old__, new__)); \
- \
- old__; \
- })
- #endif
- #ifndef bit_clear_unless
- #define bit_clear_unless(ptr, clear, test) \
- ({ \
- const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
- typeof(*(ptr)) old__, new__; \
- \
- old__ = READ_ONCE(*(ptr)); \
- do { \
- if (old__ & test__) \
- break; \
- new__ = old__ & ~clear__; \
- } while (!try_cmpxchg(ptr, &old__, new__)); \
- \
- !(old__ & test__); \
- })
- #endif
- #endif /* __KERNEL__ */
- #endif
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