diff options
Diffstat (limited to 'include/asm-generic/bitops')
25 files changed, 1219 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/__ffs.h b/include/asm-generic/bitops/__ffs.h new file mode 100644 index 000000000..39e56e1c7 --- /dev/null +++ b/include/asm-generic/bitops/__ffs.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS___FFS_H_ +#define _ASM_GENERIC_BITOPS___FFS_H_ + +#include <asm/types.h> + +/** + * __ffs - find first bit in word. + * @word: The word to search + * + * Undefined if no bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __ffs(unsigned long word) +{ + int num = 0; + +#if BITS_PER_LONG == 64 + if ((word & 0xffffffff) == 0) { + num += 32; + word >>= 32; + } +#endif + if ((word & 0xffff) == 0) { + num += 16; + word >>= 16; + } + if ((word & 0xff) == 0) { + num += 8; + word >>= 8; + } + if ((word & 0xf) == 0) { + num += 4; + word >>= 4; + } + if ((word & 0x3) == 0) { + num += 2; + word >>= 2; + } + if ((word & 0x1) == 0) + num += 1; + return num; +} + +#endif /* _ASM_GENERIC_BITOPS___FFS_H_ */ diff --git a/include/asm-generic/bitops/__fls.h b/include/asm-generic/bitops/__fls.h new file mode 100644 index 000000000..03f721a8a --- /dev/null +++ b/include/asm-generic/bitops/__fls.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS___FLS_H_ +#define _ASM_GENERIC_BITOPS___FLS_H_ + +#include <asm/types.h> + +/** + * __fls - find last (most-significant) set bit in a long word + * @word: the word to search + * + * Undefined if no set bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __fls(unsigned long word) +{ + int num = BITS_PER_LONG - 1; + +#if BITS_PER_LONG == 64 + if (!(word & (~0ul << 32))) { + num -= 32; + word <<= 32; + } +#endif + if (!(word & (~0ul << (BITS_PER_LONG-16)))) { + num -= 16; + word <<= 16; + } + if (!(word & (~0ul << (BITS_PER_LONG-8)))) { + num -= 8; + word <<= 8; + } + if (!(word & (~0ul << (BITS_PER_LONG-4)))) { + num -= 4; + word <<= 4; + } + if (!(word & (~0ul << (BITS_PER_LONG-2)))) { + num -= 2; + word <<= 2; + } + if (!(word & (~0ul << (BITS_PER_LONG-1)))) + num -= 1; + return num; +} + +#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */ diff --git a/include/asm-generic/bitops/arch_hweight.h b/include/asm-generic/bitops/arch_hweight.h new file mode 100644 index 000000000..c2705e1d2 --- /dev/null +++ b/include/asm-generic/bitops/arch_hweight.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_ARCH_HWEIGHT_H_ +#define _ASM_GENERIC_BITOPS_ARCH_HWEIGHT_H_ + +#include <asm/types.h> + +static inline unsigned int __arch_hweight32(unsigned int w) +{ + return __sw_hweight32(w); +} + +static inline unsigned int __arch_hweight16(unsigned int w) +{ + return __sw_hweight16(w); +} + +static inline unsigned int __arch_hweight8(unsigned int w) +{ + return __sw_hweight8(w); +} + +static inline unsigned long __arch_hweight64(__u64 w) +{ + return __sw_hweight64(w); +} +#endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */ diff --git a/include/asm-generic/bitops/atomic.h b/include/asm-generic/bitops/atomic.h new file mode 100644 index 000000000..71ab4ba9c --- /dev/null +++ b/include/asm-generic/bitops/atomic.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_ATOMIC_H_ + +#include <linux/atomic.h> +#include <linux/compiler.h> +#include <asm/barrier.h> + +/* + * Implementation of atomic bitops using atomic-fetch ops. + * See Documentation/atomic_bitops.txt for details. + */ + +static __always_inline void +arch_set_bit(unsigned int nr, volatile unsigned long *p) +{ + p += BIT_WORD(nr); + arch_atomic_long_or(BIT_MASK(nr), (atomic_long_t *)p); +} + +static __always_inline void +arch_clear_bit(unsigned int nr, volatile unsigned long *p) +{ + p += BIT_WORD(nr); + arch_atomic_long_andnot(BIT_MASK(nr), (atomic_long_t *)p); +} + +static __always_inline void +arch_change_bit(unsigned int nr, volatile unsigned long *p) +{ + p += BIT_WORD(nr); + arch_atomic_long_xor(BIT_MASK(nr), (atomic_long_t *)p); +} + +static __always_inline int +arch_test_and_set_bit(unsigned int nr, volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + old = arch_atomic_long_fetch_or(mask, (atomic_long_t *)p); + return !!(old & mask); +} + +static __always_inline int +arch_test_and_clear_bit(unsigned int nr, volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + old = arch_atomic_long_fetch_andnot(mask, (atomic_long_t *)p); + return !!(old & mask); +} + +static __always_inline int +arch_test_and_change_bit(unsigned int nr, volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + old = arch_atomic_long_fetch_xor(mask, (atomic_long_t *)p); + return !!(old & mask); +} + +#include <asm-generic/bitops/instrumented-atomic.h> + +#endif /* _ASM_GENERIC_BITOPS_ATOMIC_H */ diff --git a/include/asm-generic/bitops/builtin-__ffs.h b/include/asm-generic/bitops/builtin-__ffs.h new file mode 100644 index 000000000..87024da44 --- /dev/null +++ b/include/asm-generic/bitops/builtin-__ffs.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_BUILTIN___FFS_H_ +#define _ASM_GENERIC_BITOPS_BUILTIN___FFS_H_ + +/** + * __ffs - find first bit in word. + * @word: The word to search + * + * Undefined if no bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __ffs(unsigned long word) +{ + return __builtin_ctzl(word); +} + +#endif diff --git a/include/asm-generic/bitops/builtin-__fls.h b/include/asm-generic/bitops/builtin-__fls.h new file mode 100644 index 000000000..43a5aa9af --- /dev/null +++ b/include/asm-generic/bitops/builtin-__fls.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_ +#define _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_ + +/** + * __fls - find last (most-significant) set bit in a long word + * @word: the word to search + * + * Undefined if no set bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __fls(unsigned long word) +{ + return (sizeof(word) * 8) - 1 - __builtin_clzl(word); +} + +#endif diff --git a/include/asm-generic/bitops/builtin-ffs.h b/include/asm-generic/bitops/builtin-ffs.h new file mode 100644 index 000000000..7b1293290 --- /dev/null +++ b/include/asm-generic/bitops/builtin-ffs.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_BUILTIN_FFS_H_ +#define _ASM_GENERIC_BITOPS_BUILTIN_FFS_H_ + +/** + * ffs - find first bit set + * @x: the word to search + * + * This is defined the same way as + * the libc and compiler builtin ffs routines, therefore + * differs in spirit from ffz (man ffs). + */ +#define ffs(x) __builtin_ffs(x) + +#endif diff --git a/include/asm-generic/bitops/builtin-fls.h b/include/asm-generic/bitops/builtin-fls.h new file mode 100644 index 000000000..c8455cc28 --- /dev/null +++ b/include/asm-generic/bitops/builtin-fls.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_ +#define _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_ + +/** + * fls - find last (most-significant) bit set + * @x: the word to search + * + * This is defined the same way as ffs. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ +static __always_inline int fls(unsigned int x) +{ + return x ? sizeof(x) * 8 - __builtin_clz(x) : 0; +} + +#endif diff --git a/include/asm-generic/bitops/const_hweight.h b/include/asm-generic/bitops/const_hweight.h new file mode 100644 index 000000000..149faeeee --- /dev/null +++ b/include/asm-generic/bitops/const_hweight.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ +#define _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ + +/* + * Compile time versions of __arch_hweightN() + */ +#define __const_hweight8(w) \ + ((unsigned int) \ + ((!!((w) & (1ULL << 0))) + \ + (!!((w) & (1ULL << 1))) + \ + (!!((w) & (1ULL << 2))) + \ + (!!((w) & (1ULL << 3))) + \ + (!!((w) & (1ULL << 4))) + \ + (!!((w) & (1ULL << 5))) + \ + (!!((w) & (1ULL << 6))) + \ + (!!((w) & (1ULL << 7))))) + +#define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 )) +#define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16)) +#define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32)) + +/* + * Generic interface. + */ +#define hweight8(w) (__builtin_constant_p(w) ? __const_hweight8(w) : __arch_hweight8(w)) +#define hweight16(w) (__builtin_constant_p(w) ? __const_hweight16(w) : __arch_hweight16(w)) +#define hweight32(w) (__builtin_constant_p(w) ? __const_hweight32(w) : __arch_hweight32(w)) +#define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w)) + +/* + * Interface for known constant arguments + */ +#define HWEIGHT8(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight8(w)) +#define HWEIGHT16(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight16(w)) +#define HWEIGHT32(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight32(w)) +#define HWEIGHT64(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight64(w)) + +/* + * Type invariant interface to the compile time constant hweight functions. + */ +#define HWEIGHT(w) HWEIGHT64((u64)w) + +#endif /* _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ */ diff --git a/include/asm-generic/bitops/ext2-atomic-setbit.h b/include/asm-generic/bitops/ext2-atomic-setbit.h new file mode 100644 index 000000000..b041cbf0d --- /dev/null +++ b/include/asm-generic/bitops/ext2-atomic-setbit.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_EXT2_ATOMIC_SETBIT_H_ +#define _ASM_GENERIC_BITOPS_EXT2_ATOMIC_SETBIT_H_ + +/* + * Atomic bitops based version of ext2 atomic bitops + */ + +#define ext2_set_bit_atomic(l, nr, addr) test_and_set_bit_le(nr, addr) +#define ext2_clear_bit_atomic(l, nr, addr) test_and_clear_bit_le(nr, addr) + +#endif /* _ASM_GENERIC_BITOPS_EXT2_ATOMIC_SETBIT_H_ */ diff --git a/include/asm-generic/bitops/ext2-atomic.h b/include/asm-generic/bitops/ext2-atomic.h new file mode 100644 index 000000000..0cfc3180b --- /dev/null +++ b/include/asm-generic/bitops/ext2-atomic.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_EXT2_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_EXT2_ATOMIC_H_ + +/* + * Spinlock based version of ext2 atomic bitops + */ + +#define ext2_set_bit_atomic(lock, nr, addr) \ + ({ \ + int ret; \ + spin_lock(lock); \ + ret = __test_and_set_bit_le(nr, addr); \ + spin_unlock(lock); \ + ret; \ + }) + +#define ext2_clear_bit_atomic(lock, nr, addr) \ + ({ \ + int ret; \ + spin_lock(lock); \ + ret = __test_and_clear_bit_le(nr, addr); \ + spin_unlock(lock); \ + ret; \ + }) + +#endif /* _ASM_GENERIC_BITOPS_EXT2_ATOMIC_H_ */ diff --git a/include/asm-generic/bitops/ffs.h b/include/asm-generic/bitops/ffs.h new file mode 100644 index 000000000..323fd5d6a --- /dev/null +++ b/include/asm-generic/bitops/ffs.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FFS_H_ +#define _ASM_GENERIC_BITOPS_FFS_H_ + +/** + * ffs - find first bit set + * @x: the word to search + * + * This is defined the same way as + * the libc and compiler builtin ffs routines, therefore + * differs in spirit from ffz (man ffs). + */ +static inline int ffs(int x) +{ + int r = 1; + + if (!x) + return 0; + if (!(x & 0xffff)) { + x >>= 16; + r += 16; + } + if (!(x & 0xff)) { + x >>= 8; + r += 8; + } + if (!(x & 0xf)) { + x >>= 4; + r += 4; + } + if (!(x & 3)) { + x >>= 2; + r += 2; + } + if (!(x & 1)) { + x >>= 1; + r += 1; + } + return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */ diff --git a/include/asm-generic/bitops/ffz.h b/include/asm-generic/bitops/ffz.h new file mode 100644 index 000000000..0d010085f --- /dev/null +++ b/include/asm-generic/bitops/ffz.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FFZ_H_ +#define _ASM_GENERIC_BITOPS_FFZ_H_ + +/* + * ffz - find first zero in word. + * @word: The word to search + * + * Undefined if no zero exists, so code should check against ~0UL first. + */ +#define ffz(x) __ffs(~(x)) + +#endif /* _ASM_GENERIC_BITOPS_FFZ_H_ */ diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h new file mode 100644 index 000000000..b168bb10e --- /dev/null +++ b/include/asm-generic/bitops/fls.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FLS_H_ +#define _ASM_GENERIC_BITOPS_FLS_H_ + +/** + * fls - find last (most-significant) bit set + * @x: the word to search + * + * This is defined the same way as ffs. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ + +static __always_inline int fls(unsigned int x) +{ + int r = 32; + + if (!x) + return 0; + if (!(x & 0xffff0000u)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xff000000u)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xf0000000u)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xc0000000u)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000u)) { + x <<= 1; + r -= 1; + } + return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ diff --git a/include/asm-generic/bitops/fls64.h b/include/asm-generic/bitops/fls64.h new file mode 100644 index 000000000..866f2b230 --- /dev/null +++ b/include/asm-generic/bitops/fls64.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FLS64_H_ +#define _ASM_GENERIC_BITOPS_FLS64_H_ + +#include <asm/types.h> + +/** + * fls64 - find last set bit in a 64-bit word + * @x: the word to search + * + * This is defined in a similar way as the libc and compiler builtin + * ffsll, but returns the position of the most significant set bit. + * + * fls64(value) returns 0 if value is 0 or the position of the last + * set bit if value is nonzero. The last (most significant) bit is + * at position 64. + */ +#if BITS_PER_LONG == 32 +static __always_inline int fls64(__u64 x) +{ + __u32 h = x >> 32; + if (h) + return fls(h) + 32; + return fls(x); +} +#elif BITS_PER_LONG == 64 +static __always_inline int fls64(__u64 x) +{ + if (x == 0) + return 0; + return __fls(x) + 1; +} +#else +#error BITS_PER_LONG not 32 or 64 +#endif + +#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */ diff --git a/include/asm-generic/bitops/generic-non-atomic.h b/include/asm-generic/bitops/generic-non-atomic.h new file mode 100644 index 000000000..564a8c675 --- /dev/null +++ b/include/asm-generic/bitops/generic-non-atomic.h @@ -0,0 +1,175 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __ASM_GENERIC_BITOPS_GENERIC_NON_ATOMIC_H +#define __ASM_GENERIC_BITOPS_GENERIC_NON_ATOMIC_H + +#include <linux/bits.h> +#include <asm/barrier.h> + +#ifndef _LINUX_BITOPS_H +#error only <linux/bitops.h> can be included directly +#endif + +/* + * Generic definitions for bit operations, should not be used in regular code + * directly. + */ + +/** + * generic___set_bit - Set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Unlike set_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. + */ +static __always_inline void +generic___set_bit(unsigned long nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p |= mask; +} + +static __always_inline void +generic___clear_bit(unsigned long nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p &= ~mask; +} + +/** + * generic___change_bit - Toggle a bit in memory + * @nr: the bit to change + * @addr: the address to start counting from + * + * Unlike change_bit(), this function is non-atomic and may be reordered. + * If it's called on the same region of memory simultaneously, the effect + * may be that only one operation succeeds. + */ +static __always_inline void +generic___change_bit(unsigned long nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p ^= mask; +} + +/** + * generic___test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static __always_inline bool +generic___test_and_set_bit(unsigned long nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old | mask; + return (old & mask) != 0; +} + +/** + * generic___test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static __always_inline bool +generic___test_and_clear_bit(unsigned long nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old & ~mask; + return (old & mask) != 0; +} + +/* WARNING: non atomic and it can be reordered! */ +static __always_inline bool +generic___test_and_change_bit(unsigned long nr, volatile unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old ^ mask; + return (old & mask) != 0; +} + +/** + * generic_test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static __always_inline bool +generic_test_bit(unsigned long nr, const volatile unsigned long *addr) +{ + /* + * Unlike the bitops with the '__' prefix above, this one *is* atomic, + * so `volatile` must always stay here with no cast-aways. See + * `Documentation/atomic_bitops.txt` for the details. + */ + return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); +} + +/** + * generic_test_bit_acquire - Determine, with acquire semantics, whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static __always_inline bool +generic_test_bit_acquire(unsigned long nr, const volatile unsigned long *addr) +{ + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + return 1UL & (smp_load_acquire(p) >> (nr & (BITS_PER_LONG-1))); +} + +/* + * const_*() definitions provide good compile-time optimizations when + * the passed arguments can be resolved at compile time. + */ +#define const___set_bit generic___set_bit +#define const___clear_bit generic___clear_bit +#define const___change_bit generic___change_bit +#define const___test_and_set_bit generic___test_and_set_bit +#define const___test_and_clear_bit generic___test_and_clear_bit +#define const___test_and_change_bit generic___test_and_change_bit +#define const_test_bit_acquire generic_test_bit_acquire + +/** + * const_test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + * + * A version of generic_test_bit() which discards the `volatile` qualifier to + * allow a compiler to optimize code harder. Non-atomic and to be called only + * for testing compile-time constants, e.g. by the corresponding macros, not + * directly from "regular" code. + */ +static __always_inline bool +const_test_bit(unsigned long nr, const volatile unsigned long *addr) +{ + const unsigned long *p = (const unsigned long *)addr + BIT_WORD(nr); + unsigned long mask = BIT_MASK(nr); + unsigned long val = *p; + + return !!(val & mask); +} + +#endif /* __ASM_GENERIC_BITOPS_GENERIC_NON_ATOMIC_H */ diff --git a/include/asm-generic/bitops/hweight.h b/include/asm-generic/bitops/hweight.h new file mode 100644 index 000000000..6bf1bba83 --- /dev/null +++ b/include/asm-generic/bitops/hweight.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_HWEIGHT_H_ +#define _ASM_GENERIC_BITOPS_HWEIGHT_H_ + +#include <asm-generic/bitops/arch_hweight.h> +#include <asm-generic/bitops/const_hweight.h> + +#endif /* _ASM_GENERIC_BITOPS_HWEIGHT_H_ */ diff --git a/include/asm-generic/bitops/instrumented-atomic.h b/include/asm-generic/bitops/instrumented-atomic.h new file mode 100644 index 000000000..4225a8ca9 --- /dev/null +++ b/include/asm-generic/bitops/instrumented-atomic.h @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This file provides wrappers with sanitizer instrumentation for atomic bit + * operations. + * + * To use this functionality, an arch's bitops.h file needs to define each of + * the below bit operations with an arch_ prefix (e.g. arch_set_bit(), + * arch___set_bit(), etc.). + */ +#ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H +#define _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H + +#include <linux/instrumented.h> + +/** + * set_bit - Atomically set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * This is a relaxed atomic operation (no implied memory barriers). + * + * Note that @nr may be almost arbitrarily large; this function is not + * restricted to acting on a single-word quantity. + */ +static __always_inline void set_bit(long nr, volatile unsigned long *addr) +{ + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); + arch_set_bit(nr, addr); +} + +/** + * clear_bit - Clears a bit in memory + * @nr: Bit to clear + * @addr: Address to start counting from + * + * This is a relaxed atomic operation (no implied memory barriers). + */ +static __always_inline void clear_bit(long nr, volatile unsigned long *addr) +{ + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); + arch_clear_bit(nr, addr); +} + +/** + * change_bit - Toggle a bit in memory + * @nr: Bit to change + * @addr: Address to start counting from + * + * This is a relaxed atomic operation (no implied memory barriers). + * + * Note that @nr may be almost arbitrarily large; this function is not + * restricted to acting on a single-word quantity. + */ +static __always_inline void change_bit(long nr, volatile unsigned long *addr) +{ + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); + arch_change_bit(nr, addr); +} + +/** + * test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This is an atomic fully-ordered operation (implied full memory barrier). + */ +static __always_inline bool test_and_set_bit(long nr, volatile unsigned long *addr) +{ + kcsan_mb(); + instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long)); + return arch_test_and_set_bit(nr, addr); +} + +/** + * test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This is an atomic fully-ordered operation (implied full memory barrier). + */ +static __always_inline bool test_and_clear_bit(long nr, volatile unsigned long *addr) +{ + kcsan_mb(); + instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long)); + return arch_test_and_clear_bit(nr, addr); +} + +/** + * test_and_change_bit - Change a bit and return its old value + * @nr: Bit to change + * @addr: Address to count from + * + * This is an atomic fully-ordered operation (implied full memory barrier). + */ +static __always_inline bool test_and_change_bit(long nr, volatile unsigned long *addr) +{ + kcsan_mb(); + instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long)); + return arch_test_and_change_bit(nr, addr); +} + +#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */ diff --git a/include/asm-generic/bitops/instrumented-lock.h b/include/asm-generic/bitops/instrumented-lock.h new file mode 100644 index 000000000..eb64bd4f1 --- /dev/null +++ b/include/asm-generic/bitops/instrumented-lock.h @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This file provides wrappers with sanitizer instrumentation for bit + * locking operations. + * + * To use this functionality, an arch's bitops.h file needs to define each of + * the below bit operations with an arch_ prefix (e.g. arch_set_bit(), + * arch___set_bit(), etc.). + */ +#ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H +#define _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H + +#include <linux/instrumented.h> + +/** + * clear_bit_unlock - Clear a bit in memory, for unlock + * @nr: the bit to set + * @addr: the address to start counting from + * + * This operation is atomic and provides release barrier semantics. + */ +static inline void clear_bit_unlock(long nr, volatile unsigned long *addr) +{ + kcsan_release(); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); + arch_clear_bit_unlock(nr, addr); +} + +/** + * __clear_bit_unlock - Clears a bit in memory + * @nr: Bit to clear + * @addr: Address to start counting from + * + * This is a non-atomic operation but implies a release barrier before the + * memory operation. It can be used for an unlock if no other CPUs can + * concurrently modify other bits in the word. + */ +static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr) +{ + kcsan_release(); + instrument_write(addr + BIT_WORD(nr), sizeof(long)); + arch___clear_bit_unlock(nr, addr); +} + +/** + * test_and_set_bit_lock - Set a bit and return its old value, for lock + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is atomic and provides acquire barrier semantics if + * the returned value is 0. + * It can be used to implement bit locks. + */ +static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr) +{ + instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long)); + return arch_test_and_set_bit_lock(nr, addr); +} + +#if defined(arch_clear_bit_unlock_is_negative_byte) +/** + * clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom + * byte is negative, for unlock. + * @nr: the bit to clear + * @addr: the address to start counting from + * + * This operation is atomic and provides release barrier semantics. + * + * This is a bit of a one-trick-pony for the filemap code, which clears + * PG_locked and tests PG_waiters, + */ +static inline bool +clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr) +{ + kcsan_release(); + instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long)); + return arch_clear_bit_unlock_is_negative_byte(nr, addr); +} +/* Let everybody know we have it. */ +#define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte +#endif + +#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H */ diff --git a/include/asm-generic/bitops/instrumented-non-atomic.h b/include/asm-generic/bitops/instrumented-non-atomic.h new file mode 100644 index 000000000..2b238b161 --- /dev/null +++ b/include/asm-generic/bitops/instrumented-non-atomic.h @@ -0,0 +1,157 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This file provides wrappers with sanitizer instrumentation for non-atomic + * bit operations. + * + * To use this functionality, an arch's bitops.h file needs to define each of + * the below bit operations with an arch_ prefix (e.g. arch_set_bit(), + * arch___set_bit(), etc.). + */ +#ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H +#define _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H + +#include <linux/instrumented.h> + +/** + * ___set_bit - Set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Unlike set_bit(), this function is non-atomic. If it is called on the same + * region of memory concurrently, the effect may be that only one operation + * succeeds. + */ +static __always_inline void +___set_bit(unsigned long nr, volatile unsigned long *addr) +{ + instrument_write(addr + BIT_WORD(nr), sizeof(long)); + arch___set_bit(nr, addr); +} + +/** + * ___clear_bit - Clears a bit in memory + * @nr: the bit to clear + * @addr: the address to start counting from + * + * Unlike clear_bit(), this function is non-atomic. If it is called on the same + * region of memory concurrently, the effect may be that only one operation + * succeeds. + */ +static __always_inline void +___clear_bit(unsigned long nr, volatile unsigned long *addr) +{ + instrument_write(addr + BIT_WORD(nr), sizeof(long)); + arch___clear_bit(nr, addr); +} + +/** + * ___change_bit - Toggle a bit in memory + * @nr: the bit to change + * @addr: the address to start counting from + * + * Unlike change_bit(), this function is non-atomic. If it is called on the same + * region of memory concurrently, the effect may be that only one operation + * succeeds. + */ +static __always_inline void +___change_bit(unsigned long nr, volatile unsigned long *addr) +{ + instrument_write(addr + BIT_WORD(nr), sizeof(long)); + arch___change_bit(nr, addr); +} + +static __always_inline void __instrument_read_write_bitop(long nr, volatile unsigned long *addr) +{ + if (IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC)) { + /* + * We treat non-atomic read-write bitops a little more special. + * Given the operations here only modify a single bit, assuming + * non-atomicity of the writer is sufficient may be reasonable + * for certain usage (and follows the permissible nature of the + * assume-plain-writes-atomic rule): + * 1. report read-modify-write races -> check read; + * 2. do not report races with marked readers, but do report + * races with unmarked readers -> check "atomic" write. + */ + kcsan_check_read(addr + BIT_WORD(nr), sizeof(long)); + /* + * Use generic write instrumentation, in case other sanitizers + * or tools are enabled alongside KCSAN. + */ + instrument_write(addr + BIT_WORD(nr), sizeof(long)); + } else { + instrument_read_write(addr + BIT_WORD(nr), sizeof(long)); + } +} + +/** + * ___test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is non-atomic. If two instances of this operation race, one + * can appear to succeed but actually fail. + */ +static __always_inline bool +___test_and_set_bit(unsigned long nr, volatile unsigned long *addr) +{ + __instrument_read_write_bitop(nr, addr); + return arch___test_and_set_bit(nr, addr); +} + +/** + * ___test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation is non-atomic. If two instances of this operation race, one + * can appear to succeed but actually fail. + */ +static __always_inline bool +___test_and_clear_bit(unsigned long nr, volatile unsigned long *addr) +{ + __instrument_read_write_bitop(nr, addr); + return arch___test_and_clear_bit(nr, addr); +} + +/** + * ___test_and_change_bit - Change a bit and return its old value + * @nr: Bit to change + * @addr: Address to count from + * + * This operation is non-atomic. If two instances of this operation race, one + * can appear to succeed but actually fail. + */ +static __always_inline bool +___test_and_change_bit(unsigned long nr, volatile unsigned long *addr) +{ + __instrument_read_write_bitop(nr, addr); + return arch___test_and_change_bit(nr, addr); +} + +/** + * _test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static __always_inline bool +_test_bit(unsigned long nr, const volatile unsigned long *addr) +{ + instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long)); + return arch_test_bit(nr, addr); +} + +/** + * _test_bit_acquire - Determine, with acquire semantics, whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static __always_inline bool +_test_bit_acquire(unsigned long nr, const volatile unsigned long *addr) +{ + instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long)); + return arch_test_bit_acquire(nr, addr); +} + +#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */ diff --git a/include/asm-generic/bitops/le.h b/include/asm-generic/bitops/le.h new file mode 100644 index 000000000..d51beff60 --- /dev/null +++ b/include/asm-generic/bitops/le.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_LE_H_ +#define _ASM_GENERIC_BITOPS_LE_H_ + +#include <asm/types.h> +#include <asm/byteorder.h> + +#if defined(__LITTLE_ENDIAN) + +#define BITOP_LE_SWIZZLE 0 + +#elif defined(__BIG_ENDIAN) + +#define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) + +#endif + + +static inline int test_bit_le(int nr, const void *addr) +{ + return test_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline void set_bit_le(int nr, void *addr) +{ + set_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline void clear_bit_le(int nr, void *addr) +{ + clear_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline void __set_bit_le(int nr, void *addr) +{ + __set_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline void __clear_bit_le(int nr, void *addr) +{ + __clear_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline int test_and_set_bit_le(int nr, void *addr) +{ + return test_and_set_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline int test_and_clear_bit_le(int nr, void *addr) +{ + return test_and_clear_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline int __test_and_set_bit_le(int nr, void *addr) +{ + return __test_and_set_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +static inline int __test_and_clear_bit_le(int nr, void *addr) +{ + return __test_and_clear_bit(nr ^ BITOP_LE_SWIZZLE, addr); +} + +#endif /* _ASM_GENERIC_BITOPS_LE_H_ */ diff --git a/include/asm-generic/bitops/lock.h b/include/asm-generic/bitops/lock.h new file mode 100644 index 000000000..630f2f6b9 --- /dev/null +++ b/include/asm-generic/bitops/lock.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_LOCK_H_ +#define _ASM_GENERIC_BITOPS_LOCK_H_ + +#include <linux/atomic.h> +#include <linux/compiler.h> +#include <asm/barrier.h> + +/** + * arch_test_and_set_bit_lock - Set a bit and return its old value, for lock + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is atomic and provides acquire barrier semantics if + * the returned value is 0. + * It can be used to implement bit locks. + */ +static __always_inline int +arch_test_and_set_bit_lock(unsigned int nr, volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + if (READ_ONCE(*p) & mask) + return 1; + + old = arch_atomic_long_fetch_or_acquire(mask, (atomic_long_t *)p); + return !!(old & mask); +} + + +/** + * arch_clear_bit_unlock - Clear a bit in memory, for unlock + * @nr: the bit to set + * @addr: the address to start counting from + * + * This operation is atomic and provides release barrier semantics. + */ +static __always_inline void +arch_clear_bit_unlock(unsigned int nr, volatile unsigned long *p) +{ + p += BIT_WORD(nr); + arch_atomic_long_fetch_andnot_release(BIT_MASK(nr), (atomic_long_t *)p); +} + +/** + * arch___clear_bit_unlock - Clear a bit in memory, for unlock + * @nr: the bit to set + * @addr: the address to start counting from + * + * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all + * the bits in the word are protected by this lock some archs can use weaker + * ops to safely unlock. + * + * See for example x86's implementation. + */ +static inline void +arch___clear_bit_unlock(unsigned int nr, volatile unsigned long *p) +{ + unsigned long old; + + p += BIT_WORD(nr); + old = READ_ONCE(*p); + old &= ~BIT_MASK(nr); + arch_atomic_long_set_release((atomic_long_t *)p, old); +} + +/** + * arch_clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom + * byte is negative, for unlock. + * @nr: the bit to clear + * @addr: the address to start counting from + * + * This is a bit of a one-trick-pony for the filemap code, which clears + * PG_locked and tests PG_waiters, + */ +#ifndef arch_clear_bit_unlock_is_negative_byte +static inline bool arch_clear_bit_unlock_is_negative_byte(unsigned int nr, + volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + old = arch_atomic_long_fetch_andnot_release(mask, (atomic_long_t *)p); + return !!(old & BIT(7)); +} +#define arch_clear_bit_unlock_is_negative_byte arch_clear_bit_unlock_is_negative_byte +#endif + +#include <asm-generic/bitops/instrumented-lock.h> + +#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ diff --git a/include/asm-generic/bitops/non-atomic.h b/include/asm-generic/bitops/non-atomic.h new file mode 100644 index 000000000..71f8d54a5 --- /dev/null +++ b/include/asm-generic/bitops/non-atomic.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ + +#include <asm-generic/bitops/generic-non-atomic.h> + +#define arch___set_bit generic___set_bit +#define arch___clear_bit generic___clear_bit +#define arch___change_bit generic___change_bit + +#define arch___test_and_set_bit generic___test_and_set_bit +#define arch___test_and_clear_bit generic___test_and_clear_bit +#define arch___test_and_change_bit generic___test_and_change_bit + +#define arch_test_bit generic_test_bit +#define arch_test_bit_acquire generic_test_bit_acquire + +#include <asm-generic/bitops/non-instrumented-non-atomic.h> + +#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ diff --git a/include/asm-generic/bitops/non-instrumented-non-atomic.h b/include/asm-generic/bitops/non-instrumented-non-atomic.h new file mode 100644 index 000000000..0ddc78dfc --- /dev/null +++ b/include/asm-generic/bitops/non-instrumented-non-atomic.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_GENERIC_BITOPS_NON_INSTRUMENTED_NON_ATOMIC_H +#define __ASM_GENERIC_BITOPS_NON_INSTRUMENTED_NON_ATOMIC_H + +#define ___set_bit arch___set_bit +#define ___clear_bit arch___clear_bit +#define ___change_bit arch___change_bit + +#define ___test_and_set_bit arch___test_and_set_bit +#define ___test_and_clear_bit arch___test_and_clear_bit +#define ___test_and_change_bit arch___test_and_change_bit + +#define _test_bit arch_test_bit +#define _test_bit_acquire arch_test_bit_acquire + +#endif /* __ASM_GENERIC_BITOPS_NON_INSTRUMENTED_NON_ATOMIC_H */ diff --git a/include/asm-generic/bitops/sched.h b/include/asm-generic/bitops/sched.h new file mode 100644 index 000000000..86470cfce --- /dev/null +++ b/include/asm-generic/bitops/sched.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_SCHED_H_ +#define _ASM_GENERIC_BITOPS_SCHED_H_ + +#include <linux/compiler.h> /* unlikely() */ +#include <asm/types.h> + +/* + * Every architecture must define this function. It's the fastest + * way of searching a 100-bit bitmap. It's guaranteed that at least + * one of the 100 bits is cleared. + */ +static inline int sched_find_first_bit(const unsigned long *b) +{ +#if BITS_PER_LONG == 64 + if (b[0]) + return __ffs(b[0]); + return __ffs(b[1]) + 64; +#elif BITS_PER_LONG == 32 + if (b[0]) + return __ffs(b[0]); + if (b[1]) + return __ffs(b[1]) + 32; + if (b[2]) + return __ffs(b[2]) + 64; + return __ffs(b[3]) + 96; +#else +#error BITS_PER_LONG not defined +#endif +} + +#endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */ |