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/* SPDX-License-Identifier: GPL-2.0-only */ #ifndef _ASM_ARC_ATOMIC_SPLOCK_H #define _ASM_ARC_ATOMIC_SPLOCK_H /* * Non hardware assisted Atomic-R-M-W * Locking would change to irq-disabling only (UP) and spinlocks (SMP) */ static inline void arch_atomic_set(atomic_t *v, int i) { /* * Independent of hardware support, all of the atomic_xxx() APIs need * to follow the same locking rules to make sure that a "hardware" * atomic insn (e.g. LD) doesn't clobber an "emulated" atomic insn * sequence * * Thus atomic_set() despite being 1 insn (and seemingly atomic) * requires the locking. */ unsigned long flags; atomic_ops_lock(flags); WRITE_ONCE(v->counter, i); atomic_ops_unlock(flags); } #define arch_atomic_set_release(v, i) arch_atomic_set((v), (i)) #define ATOMIC_OP(op, c_op, asm_op) \ static inline void arch_atomic_##op(int i, atomic_t *v) \ { \ unsigned long flags; \ \ atomic_ops_lock(flags); \ v->counter c_op i; \ atomic_ops_unlock(flags); \ } #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ static inline int arch_atomic_##op##_return(int i, atomic_t *v) \ { \ unsigned long flags; \ unsigned int temp; \ \ /* \ * spin lock/unlock provides the needed smp_mb() before/after \ */ \ atomic_ops_lock(flags); \ temp = v->counter; \ temp c_op i; \ v->counter = temp; \ atomic_ops_unlock(flags); \ \ return temp; \ } #define ATOMIC_FETCH_OP(op, c_op, asm_op) \ static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \ { \ unsigned long flags; \ unsigned int orig; \ \ /* \ * spin lock/unlock provides the needed smp_mb() before/after \ */ \ atomic_ops_lock(flags); \ orig = v->counter; \ v->counter c_op i; \ atomic_ops_unlock(flags); \ \ return orig; \ } #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ ATOMIC_OP_RETURN(op, c_op, asm_op) \ ATOMIC_FETCH_OP(op, c_op, asm_op) ATOMIC_OPS(add, +=, add) ATOMIC_OPS(sub, -=, sub) #undef ATOMIC_OPS #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ ATOMIC_FETCH_OP(op, c_op, asm_op) ATOMIC_OPS(and, &=, and) ATOMIC_OPS(andnot, &= ~, bic) ATOMIC_OPS(or, |=, or) ATOMIC_OPS(xor, ^=, xor) #define arch_atomic_andnot arch_atomic_andnot #define arch_atomic_fetch_andnot arch_atomic_fetch_andnot #undef ATOMIC_OPS #undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP #endif |