1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 3 #ifndef _ASM_ARC_ATOMIC_SPLOCK_H 4 #define _ASM_ARC_ATOMIC_SPLOCK_H 5 6 /* 7 * Non hardware assisted Atomic-R-M-W 8 * Locking would change to irq-disabling only (UP) and spinlocks (SMP) 9 */ 10 11 static inline void arch_atomic_set(atomic_t *v, int i) 12 { 13 /* 14 * Independent of hardware support, all of the atomic_xxx() APIs need 15 * to follow the same locking rules to make sure that a "hardware" 16 * atomic insn (e.g. LD) doesn't clobber an "emulated" atomic insn 17 * sequence 18 * 19 * Thus atomic_set() despite being 1 insn (and seemingly atomic) 20 * requires the locking. 21 */ 22 unsigned long flags; 23 24 atomic_ops_lock(flags); 25 WRITE_ONCE(v->counter, i); 26 atomic_ops_unlock(flags); 27 } 28 29 #define arch_atomic_set_release(v, i) arch_atomic_set((v), (i)) 30 31 #define ATOMIC_OP(op, c_op, asm_op) \ 32 static inline void arch_atomic_##op(int i, atomic_t *v) \ 33 { \ 34 unsigned long flags; \ 35 \ 36 atomic_ops_lock(flags); \ 37 v->counter c_op i; \ 38 atomic_ops_unlock(flags); \ 39 } 40 41 #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ 42 static inline int arch_atomic_##op##_return(int i, atomic_t *v) \ 43 { \ 44 unsigned long flags; \ 45 unsigned int temp; \ 46 \ 47 /* \ 48 * spin lock/unlock provides the needed smp_mb() before/after \ 49 */ \ 50 atomic_ops_lock(flags); \ 51 temp = v->counter; \ 52 temp c_op i; \ 53 v->counter = temp; \ 54 atomic_ops_unlock(flags); \ 55 \ 56 return temp; \ 57 } 58 59 #define ATOMIC_FETCH_OP(op, c_op, asm_op) \ 60 static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \ 61 { \ 62 unsigned long flags; \ 63 unsigned int orig; \ 64 \ 65 /* \ 66 * spin lock/unlock provides the needed smp_mb() before/after \ 67 */ \ 68 atomic_ops_lock(flags); \ 69 orig = v->counter; \ 70 v->counter c_op i; \ 71 atomic_ops_unlock(flags); \ 72 \ 73 return orig; \ 74 } 75 76 #define ATOMIC_OPS(op, c_op, asm_op) \ 77 ATOMIC_OP(op, c_op, asm_op) \ 78 ATOMIC_OP_RETURN(op, c_op, asm_op) \ 79 ATOMIC_FETCH_OP(op, c_op, asm_op) 80 81 ATOMIC_OPS(add, +=, add) 82 ATOMIC_OPS(sub, -=, sub) 83 84 #undef ATOMIC_OPS 85 #define ATOMIC_OPS(op, c_op, asm_op) \ 86 ATOMIC_OP(op, c_op, asm_op) \ 87 ATOMIC_FETCH_OP(op, c_op, asm_op) 88 89 ATOMIC_OPS(and, &=, and) 90 ATOMIC_OPS(andnot, &= ~, bic) 91 ATOMIC_OPS(or, |=, or) 92 ATOMIC_OPS(xor, ^=, xor) 93 94 #define arch_atomic_andnot arch_atomic_andnot 95 #define arch_atomic_fetch_andnot arch_atomic_fetch_andnot 96 97 #undef ATOMIC_OPS 98 #undef ATOMIC_FETCH_OP 99 #undef ATOMIC_OP_RETURN 100 #undef ATOMIC_OP 101 102 #endif 103