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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /include/linux/bitops.h | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/linux/bitops.h')
-rw-r--r-- | include/linux/bitops.h | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h new file mode 100644 index 000000000..2ba557e06 --- /dev/null +++ b/include/linux/bitops.h @@ -0,0 +1,377 @@ +/* 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 |