// SPDX-License-Identifier: GPL-2.0+ // // An earlier version of this file appeared in the companion webpage for // "Frightening small children and disconcerting grown-ups: Concurrency // in the Linux kernel" by Alglave, Maranget, McKenney, Parri, and Stern, // which appeared in ASPLOS 2018. // ONCE READ_ONCE(X) __load{ONCE}(X) WRITE_ONCE(X,V) { __store{ONCE}(X,V); } // Release Acquire and friends smp_store_release(X,V) { __store{RELEASE}(*X,V); } smp_load_acquire(X) __load{ACQUIRE}(*X) rcu_assign_pointer(X,V) { __store{RELEASE}(X,V); } rcu_dereference(X) __load{ONCE}(X) smp_store_mb(X,V) { __store{ONCE}(X,V); __fence{MB}; } // Fences smp_mb() { __fence{MB}; } smp_rmb() { __fence{rmb}; } smp_wmb() { __fence{wmb}; } smp_mb__before_atomic() { __fence{before-atomic}; } smp_mb__after_atomic() { __fence{after-atomic}; } smp_mb__after_spinlock() { __fence{after-spinlock}; } smp_mb__after_unlock_lock() { __fence{after-unlock-lock}; } smp_mb__after_srcu_read_unlock() { __fence{after-srcu-read-unlock}; } barrier() { __fence{barrier}; } // Exchange xchg(X,V) __xchg{MB}(X,V) xchg_relaxed(X,V) __xchg{ONCE}(X,V) xchg_release(X,V) __xchg{RELEASE}(X,V) xchg_acquire(X,V) __xchg{ACQUIRE}(X,V) cmpxchg(X,V,W) __cmpxchg{MB}(X,V,W) cmpxchg_relaxed(X,V,W) __cmpxchg{ONCE}(X,V,W) cmpxchg_acquire(X,V,W) __cmpxchg{ACQUIRE}(X,V,W) cmpxchg_release(X,V,W) __cmpxchg{RELEASE}(X,V,W) // Spinlocks spin_lock(X) { __lock(X); } spin_unlock(X) { __unlock(X); } spin_trylock(X) __trylock(X) spin_is_locked(X) __islocked(X) // RCU rcu_read_lock() { __fence{rcu-lock}; } rcu_read_unlock() { __fence{rcu-unlock}; } synchronize_rcu() { __fence{sync-rcu}; } synchronize_rcu_expedited() { __fence{sync-rcu}; } // SRCU srcu_read_lock(X) __load{srcu-lock}(*X) srcu_read_unlock(X,Y) { __store{srcu-unlock}(*X,Y); } srcu_down_read(X) __load{srcu-lock}(*X) srcu_up_read(X,Y) { __store{srcu-unlock}(*X,Y); } synchronize_srcu(X) { __srcu{sync-srcu}(X); } synchronize_srcu_expedited(X) { __srcu{sync-srcu}(X); } // Atomic atomic_read(X) READ_ONCE(*X) atomic_set(X,V) { WRITE_ONCE(*X,V); } atomic_read_acquire(X) smp_load_acquire(X) atomic_set_release(X,V) { smp_store_release(X,V); } atomic_add(V,X) { __atomic_op{NORETURN}(X,+,V); } atomic_sub(V,X) { __atomic_op{NORETURN}(X,-,V); } atomic_and(V,X) { __atomic_op{NORETURN}(X,&,V); } atomic_or(V,X) { __atomic_op{NORETURN}(X,|,V); } atomic_xor(V,X) { __atomic_op{NORETURN}(X,^,V); } atomic_inc(X) { __atomic_op{NORETURN}(X,+,1); } atomic_dec(X) { __atomic_op{NORETURN}(X,-,1); } atomic_andnot(V,X) { __atomic_op{NORETURN}(X,&~,V); } atomic_add_return(V,X) __atomic_op_return{MB}(X,+,V) atomic_add_return_relaxed(V,X) __atomic_op_return{ONCE}(X,+,V) atomic_add_return_acquire(V,X) __atomic_op_return{ACQUIRE}(X,+,V) atomic_add_return_release(V,X) __atomic_op_return{RELEASE}(X,+,V) atomic_fetch_add(V,X) __atomic_fetch_op{MB}(X,+,V) atomic_fetch_add_relaxed(V,X) __atomic_fetch_op{ONCE}(X,+,V) atomic_fetch_add_acquire(V,X) __atomic_fetch_op{ACQUIRE}(X,+,V) atomic_fetch_add_release(V,X) __atomic_fetch_op{RELEASE}(X,+,V) atomic_fetch_and(V,X) __atomic_fetch_op{MB}(X,&,V) atomic_fetch_and_relaxed(V,X) __atomic_fetch_op{ONCE}(X,&,V) atomic_fetch_and_acquire(V,X) __atomic_fetch_op{ACQUIRE}(X,&,V) atomic_fetch_and_release(V,X) __atomic_fetch_op{RELEASE}(X,&,V) atomic_fetch_or(V,X) __atomic_fetch_op{MB}(X,|,V) atomic_fetch_or_relaxed(V,X) __atomic_fetch_op{ONCE}(X,|,V) atomic_fetch_or_acquire(V,X) __atomic_fetch_op{ACQUIRE}(X,|,V) atomic_fetch_or_release(V,X) __atomic_fetch_op{RELEASE}(X,|,V) atomic_fetch_xor(V,X) __atomic_fetch_op{MB}(X,^,V) atomic_fetch_xor_relaxed(V,X) __atomic_fetch_op{ONCE}(X,^,V) atomic_fetch_xor_acquire(V,X) __atomic_fetch_op{ACQUIRE}(X,^,V) atomic_fetch_xor_release(V,X) __atomic_fetch_op{RELEASE}(X,^,V) atomic_inc_return(X) __atomic_op_return{MB}(X,+,1) atomic_inc_return_relaxed(X) __atomic_op_return{ONCE}(X,+,1) atomic_inc_return_acquire(X) __atomic_op_return{ACQUIRE}(X,+,1) atomic_inc_return_release(X) __atomic_op_return{RELEASE}(X,+,1) atomic_fetch_inc(X) __atomic_fetch_op{MB}(X,+,1) atomic_fetch_inc_relaxed(X) __atomic_fetch_op{ONCE}(X,+,1) atomic_fetch_inc_acquire(X) __atomic_fetch_op{ACQUIRE}(X,+,1) atomic_fetch_inc_release(X) __atomic_fetch_op{RELEASE}(X,+,1) atomic_sub_return(V,X) __atomic_op_return{MB}(X,-,V) atomic_sub_return_relaxed(V,X) __atomic_op_return{ONCE}(X,-,V) atomic_sub_return_acquire(V,X) __atomic_op_return{ACQUIRE}(X,-,V) atomic_sub_return_release(V,X) __atomic_op_return{RELEASE}(X,-,V) atomic_fetch_sub(V,X) __atomic_fetch_op{MB}(X,-,V) atomic_fetch_sub_relaxed(V,X) __atomic_fetch_op{ONCE}(X,-,V) atomic_fetch_sub_acquire(V,X) __atomic_fetch_op{ACQUIRE}(X,-,V) atomic_fetch_sub_release(V,X) __atomic_fetch_op{RELEASE}(X,-,V) atomic_dec_return(X) __atomic_op_return{MB}(X,-,1) atomic_dec_return_relaxed(X) __atomic_op_return{ONCE}(X,-,1) atomic_dec_return_acquire(X) __atomic_op_return{ACQUIRE}(X,-,1) atomic_dec_return_release(X) __atomic_op_return{RELEASE}(X,-,1) atomic_fetch_dec(X) __atomic_fetch_op{MB}(X,-,1) atomic_fetch_dec_relaxed(X) __atomic_fetch_op{ONCE}(X,-,1) atomic_fetch_dec_acquire(X) __atomic_fetch_op{ACQUIRE}(X,-,1) atomic_fetch_dec_release(X) __atomic_fetch_op{RELEASE}(X,-,1) atomic_xchg(X,V) __xchg{MB}(X,V) atomic_xchg_relaxed(X,V) __xchg{ONCE}(X,V) atomic_xchg_release(X,V) __xchg{RELEASE}(X,V) atomic_xchg_acquire(X,V) __xchg{ACQUIRE}(X,V) atomic_cmpxchg(X,V,W) __cmpxchg{MB}(X,V,W) atomic_cmpxchg_relaxed(X,V,W) __cmpxchg{ONCE}(X,V,W) atomic_cmpxchg_acquire(X,V,W) __cmpxchg{ACQUIRE}(X,V,W) atomic_cmpxchg_release(X,V,W) __cmpxchg{RELEASE}(X,V,W) atomic_sub_and_test(V,X) __atomic_op_return{MB}(X,-,V) == 0 atomic_dec_and_test(X) __atomic_op_return{MB}(X,-,1) == 0 atomic_inc_and_test(X) __atomic_op_return{MB}(X,+,1) == 0 atomic_add_negative(V,X) __atomic_op_return{MB}(X,+,V) < 0 atomic_add_negative_relaxed(V,X) __atomic_op_return{ONCE}(X,+,V) < 0 atomic_add_negative_acquire(V,X) __atomic_op_return{ACQUIRE}(X,+,V) < 0 atomic_add_negative_release(V,X) __atomic_op_return{RELEASE}(X,+,V) < 0 atomic_fetch_andnot(V,X) __atomic_fetch_op{MB}(X,&~,V) atomic_fetch_andnot_acquire(V,X) __atomic_fetch_op{ACQUIRE}(X,&~,V) atomic_fetch_andnot_release(V,X) __atomic_fetch_op{RELEASE}(X,&~,V) atomic_fetch_andnot_relaxed(V,X) __atomic_fetch_op{ONCE}(X,&~,V) atomic_add_unless(X,V,W) __atomic_add_unless{MB}(X,V,W)