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- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef _ASM_X86_SYNC_BITOPS_H
- #define _ASM_X86_SYNC_BITOPS_H
- /*
- * Copyright 1992, Linus Torvalds.
- */
- /*
- * These have to be done with inline assembly: that way the bit-setting
- * is guaranteed to be atomic. All bit operations return 0 if the bit
- * was cleared before the operation and != 0 if it was not.
- *
- * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
- */
- #include <asm/rmwcc.h>
- #define ADDR (*(volatile long *)addr)
- /**
- * sync_set_bit - Atomically set a bit in memory
- * @nr: the bit to set
- * @addr: the address to start counting from
- *
- * This function is atomic and may not be reordered. See __set_bit()
- * if you do not require the atomic guarantees.
- *
- * Note that @nr may be almost arbitrarily large; this function is not
- * restricted to acting on a single-word quantity.
- */
- static inline void sync_set_bit(long nr, volatile unsigned long *addr)
- {
- asm volatile("lock; " __ASM_SIZE(bts) " %1,%0"
- : "+m" (ADDR)
- : "Ir" (nr)
- : "memory");
- }
- /**
- * sync_clear_bit - Clears a bit in memory
- * @nr: Bit to clear
- * @addr: Address to start counting from
- *
- * sync_clear_bit() is atomic and may not be reordered. However, it does
- * not contain a memory barrier, so if it is used for locking purposes,
- * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
- * in order to ensure changes are visible on other processors.
- */
- static inline void sync_clear_bit(long nr, volatile unsigned long *addr)
- {
- asm volatile("lock; " __ASM_SIZE(btr) " %1,%0"
- : "+m" (ADDR)
- : "Ir" (nr)
- : "memory");
- }
- /**
- * sync_change_bit - Toggle a bit in memory
- * @nr: Bit to change
- * @addr: Address to start counting from
- *
- * sync_change_bit() is atomic and may not be reordered.
- * Note that @nr may be almost arbitrarily large; this function is not
- * restricted to acting on a single-word quantity.
- */
- static inline void sync_change_bit(long nr, volatile unsigned long *addr)
- {
- asm volatile("lock; " __ASM_SIZE(btc) " %1,%0"
- : "+m" (ADDR)
- : "Ir" (nr)
- : "memory");
- }
- /**
- * sync_test_and_set_bit - Set a bit and return its old value
- * @nr: Bit to set
- * @addr: Address to count from
- *
- * This operation is atomic and cannot be reordered.
- * It also implies a memory barrier.
- */
- static inline bool sync_test_and_set_bit(long nr, volatile unsigned long *addr)
- {
- return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(bts), *addr, c, "Ir", nr);
- }
- /**
- * sync_test_and_clear_bit - Clear a bit and return its old value
- * @nr: Bit to clear
- * @addr: Address to count from
- *
- * This operation is atomic and cannot be reordered.
- * It also implies a memory barrier.
- */
- static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr)
- {
- return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(btr), *addr, c, "Ir", nr);
- }
- /**
- * sync_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 sync_test_and_change_bit(long nr, volatile unsigned long *addr)
- {
- return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(btc), *addr, c, "Ir", nr);
- }
- #define sync_test_bit(nr, addr) test_bit(nr, addr)
- #undef ADDR
- #endif /* _ASM_X86_SYNC_BITOPS_H */
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