// SPDX-License-Identifier: GPL-2.0 #include <config.h> #include "preempt.h" #include "assume.h" #include "locks.h" /* Support NR_CPUS of at most 64 */ #define CPU_PREEMPTION_LOCKS_INIT0 LOCK_IMPL_INITIALIZER #define CPU_PREEMPTION_LOCKS_INIT1 \ CPU_PREEMPTION_LOCKS_INIT0, CPU_PREEMPTION_LOCKS_INIT0 #define CPU_PREEMPTION_LOCKS_INIT2 \ CPU_PREEMPTION_LOCKS_INIT1, CPU_PREEMPTION_LOCKS_INIT1 #define CPU_PREEMPTION_LOCKS_INIT3 \ CPU_PREEMPTION_LOCKS_INIT2, CPU_PREEMPTION_LOCKS_INIT2 #define CPU_PREEMPTION_LOCKS_INIT4 \ CPU_PREEMPTION_LOCKS_INIT3, CPU_PREEMPTION_LOCKS_INIT3 #define CPU_PREEMPTION_LOCKS_INIT5 \ CPU_PREEMPTION_LOCKS_INIT4, CPU_PREEMPTION_LOCKS_INIT4 /* * Simulate disabling preemption by locking a particular cpu. NR_CPUS * should be the actual number of cpus, not just the maximum. */ struct lock_impl cpu_preemption_locks[NR_CPUS] = { CPU_PREEMPTION_LOCKS_INIT0 #if (NR_CPUS - 1) & 1 , CPU_PREEMPTION_LOCKS_INIT0 #endif #if (NR_CPUS - 1) & 2 , CPU_PREEMPTION_LOCKS_INIT1 #endif #if (NR_CPUS - 1) & 4 , CPU_PREEMPTION_LOCKS_INIT2 #endif #if (NR_CPUS - 1) & 8 , CPU_PREEMPTION_LOCKS_INIT3 #endif #if (NR_CPUS - 1) & 16 , CPU_PREEMPTION_LOCKS_INIT4 #endif #if (NR_CPUS - 1) & 32 , CPU_PREEMPTION_LOCKS_INIT5 #endif }; #undef CPU_PREEMPTION_LOCKS_INIT0 #undef CPU_PREEMPTION_LOCKS_INIT1 #undef CPU_PREEMPTION_LOCKS_INIT2 #undef CPU_PREEMPTION_LOCKS_INIT3 #undef CPU_PREEMPTION_LOCKS_INIT4 #undef CPU_PREEMPTION_LOCKS_INIT5 __thread int thread_cpu_id; __thread int preempt_disable_count; void preempt_disable(void) { BUG_ON(preempt_disable_count < 0 || preempt_disable_count == INT_MAX); if (preempt_disable_count++) return; thread_cpu_id = nondet_int(); assume(thread_cpu_id >= 0); assume(thread_cpu_id < NR_CPUS); lock_impl_lock(&cpu_preemption_locks[thread_cpu_id]); } void preempt_enable(void) { BUG_ON(preempt_disable_count < 1); if (--preempt_disable_count) return; lock_impl_unlock(&cpu_preemption_locks[thread_cpu_id]); }