| /* 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 |