1
2#include <config.h>
3
4#include "preempt.h"
5
6#include "assume.h"
7#include "locks.h"
8
9
10#define CPU_PREEMPTION_LOCKS_INIT0 LOCK_IMPL_INITIALIZER
11#define CPU_PREEMPTION_LOCKS_INIT1 \
12 CPU_PREEMPTION_LOCKS_INIT0, CPU_PREEMPTION_LOCKS_INIT0
13#define CPU_PREEMPTION_LOCKS_INIT2 \
14 CPU_PREEMPTION_LOCKS_INIT1, CPU_PREEMPTION_LOCKS_INIT1
15#define CPU_PREEMPTION_LOCKS_INIT3 \
16 CPU_PREEMPTION_LOCKS_INIT2, CPU_PREEMPTION_LOCKS_INIT2
17#define CPU_PREEMPTION_LOCKS_INIT4 \
18 CPU_PREEMPTION_LOCKS_INIT3, CPU_PREEMPTION_LOCKS_INIT3
19#define CPU_PREEMPTION_LOCKS_INIT5 \
20 CPU_PREEMPTION_LOCKS_INIT4, CPU_PREEMPTION_LOCKS_INIT4
21
22
23
24
25
26struct lock_impl cpu_preemption_locks[NR_CPUS] = {
27 CPU_PREEMPTION_LOCKS_INIT0
28#if (NR_CPUS - 1) & 1
29 , CPU_PREEMPTION_LOCKS_INIT0
30#endif
31#if (NR_CPUS - 1) & 2
32 , CPU_PREEMPTION_LOCKS_INIT1
33#endif
34#if (NR_CPUS - 1) & 4
35 , CPU_PREEMPTION_LOCKS_INIT2
36#endif
37#if (NR_CPUS - 1) & 8
38 , CPU_PREEMPTION_LOCKS_INIT3
39#endif
40#if (NR_CPUS - 1) & 16
41 , CPU_PREEMPTION_LOCKS_INIT4
42#endif
43#if (NR_CPUS - 1) & 32
44 , CPU_PREEMPTION_LOCKS_INIT5
45#endif
46};
47
48#undef CPU_PREEMPTION_LOCKS_INIT0
49#undef CPU_PREEMPTION_LOCKS_INIT1
50#undef CPU_PREEMPTION_LOCKS_INIT2
51#undef CPU_PREEMPTION_LOCKS_INIT3
52#undef CPU_PREEMPTION_LOCKS_INIT4
53#undef CPU_PREEMPTION_LOCKS_INIT5
54
55__thread int thread_cpu_id;
56__thread int preempt_disable_count;
57
58void preempt_disable(void)
59{
60 BUG_ON(preempt_disable_count < 0 || preempt_disable_count == INT_MAX);
61
62 if (preempt_disable_count++)
63 return;
64
65 thread_cpu_id = nondet_int();
66 assume(thread_cpu_id >= 0);
67 assume(thread_cpu_id < NR_CPUS);
68 lock_impl_lock(&cpu_preemption_locks[thread_cpu_id]);
69}
70
71void preempt_enable(void)
72{
73 BUG_ON(preempt_disable_count < 1);
74
75 if (--preempt_disable_count)
76 return;
77
78 lock_impl_unlock(&cpu_preemption_locks[thread_cpu_id]);
79}
80