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