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Diffstat (limited to 'arch/riscv/include/asm/bitops.h')
| -rw-r--r-- | arch/riscv/include/asm/bitops.h | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h new file mode 100644 index 000000000..3540b6909 --- /dev/null +++ b/arch/riscv/include/asm/bitops.h @@ -0,0 +1,204 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 Regents of the University of California + */ + +#ifndef _ASM_RISCV_BITOPS_H +#define _ASM_RISCV_BITOPS_H + +#ifndef _LINUX_BITOPS_H +#error "Only <linux/bitops.h> can be included directly" +#endif /* _LINUX_BITOPS_H */ + +#include <linux/compiler.h> +#include <linux/irqflags.h> +#include <asm/barrier.h> +#include <asm/bitsperlong.h> + +#include <asm-generic/bitops/__ffs.h> +#include <asm-generic/bitops/ffz.h> +#include <asm-generic/bitops/fls.h> +#include <asm-generic/bitops/__fls.h> +#include <asm-generic/bitops/fls64.h> +#include <asm-generic/bitops/sched.h> +#include <asm-generic/bitops/ffs.h> + +#include <asm-generic/bitops/hweight.h> + +#if (BITS_PER_LONG == 64) +#define __AMO(op) "amo" #op ".d" +#elif (BITS_PER_LONG == 32) +#define __AMO(op) "amo" #op ".w" +#else +#error "Unexpected BITS_PER_LONG" +#endif + +#define __test_and_op_bit_ord(op, mod, nr, addr, ord) \ +({ \ + unsigned long __res, __mask; \ + __mask = BIT_MASK(nr); \ + __asm__ __volatile__ ( \ + __AMO(op) #ord " %0, %2, %1" \ + : "=r" (__res), "+A" (addr[BIT_WORD(nr)]) \ + : "r" (mod(__mask)) \ + : "memory"); \ + ((__res & __mask) != 0); \ +}) + +#define __op_bit_ord(op, mod, nr, addr, ord) \ + __asm__ __volatile__ ( \ + __AMO(op) #ord " zero, %1, %0" \ + : "+A" (addr[BIT_WORD(nr)]) \ + : "r" (mod(BIT_MASK(nr))) \ + : "memory"); + +#define __test_and_op_bit(op, mod, nr, addr) \ + __test_and_op_bit_ord(op, mod, nr, addr, .aqrl) +#define __op_bit(op, mod, nr, addr) \ + __op_bit_ord(op, mod, nr, addr, ) + +/* Bitmask modifiers */ +#define __NOP(x) (x) +#define __NOT(x) (~(x)) + +/** + * test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation may be reordered on other architectures than x86. + */ +static inline int test_and_set_bit(int nr, volatile unsigned long *addr) +{ + return __test_and_op_bit(or, __NOP, 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 can be reordered on other architectures other than x86. + */ +static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) +{ + return __test_and_op_bit(and, __NOT, 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 atomic and cannot be reordered. + * It also implies a memory barrier. + */ +static inline int test_and_change_bit(int nr, volatile unsigned long *addr) +{ + return __test_and_op_bit(xor, __NOP, nr, addr); +} + +/** + * set_bit - Atomically set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Note: there are no guarantees that this function will not be reordered + * on non x86 architectures, so if you are writing portable code, + * make sure not to rely on its reordering guarantees. + * + * Note that @nr may be almost arbitrarily large; this function is not + * restricted to acting on a single-word quantity. + */ +static inline void set_bit(int nr, volatile unsigned long *addr) +{ + __op_bit(or, __NOP, nr, addr); +} + +/** + * clear_bit - Clears a bit in memory + * @nr: Bit to clear + * @addr: Address to start counting from + * + * Note: there are no guarantees that this function will not be reordered + * on non x86 architectures, so if you are writing portable code, + * make sure not to rely on its reordering guarantees. + */ +static inline void clear_bit(int nr, volatile unsigned long *addr) +{ + __op_bit(and, __NOT, nr, addr); +} + +/** + * change_bit - Toggle a bit in memory + * @nr: Bit to change + * @addr: Address to start counting from + * + * change_bit() may be reordered on other architectures than x86. + * Note that @nr may be almost arbitrarily large; this function is not + * restricted to acting on a single-word quantity. + */ +static inline void change_bit(int nr, volatile unsigned long *addr) +{ + __op_bit(xor, __NOP, 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. + * It can be used to implement bit locks. + */ +static inline int test_and_set_bit_lock( + unsigned long nr, volatile unsigned long *addr) +{ + return __test_and_op_bit_ord(or, __NOP, nr, addr, .aq); +} + +/** + * 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( + unsigned long nr, volatile unsigned long *addr) +{ + __op_bit_ord(and, __NOT, nr, addr, .rl); +} + +/** + * __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 like clear_bit_unlock, however it is not atomic. + * It does provide release barrier semantics so it can be used to unlock + * a bit lock, however it would only be used if no other CPU can modify + * any bits in the memory until the lock is released (a good example is + * if the bit lock itself protects access to the other bits in the word). + * + * On RISC-V systems there seems to be no benefit to taking advantage of the + * non-atomic property here: it's a lot more instructions and we still have to + * provide release semantics anyway. + */ +static inline void __clear_bit_unlock( + unsigned long nr, volatile unsigned long *addr) +{ + clear_bit_unlock(nr, addr); +} + +#undef __test_and_op_bit +#undef __op_bit +#undef __NOP +#undef __NOT +#undef __AMO + +#include <asm-generic/bitops/non-atomic.h> +#include <asm-generic/bitops/le.h> +#include <asm-generic/bitops/ext2-atomic.h> + +#endif /* _ASM_RISCV_BITOPS_H */ |