Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
bba90760 DD |
2 | #include <linux/init.h> |
3 | #include <linux/kthread.h> | |
4 | #include <linux/hrtimer.h> | |
5 | #include <linux/fs.h> | |
6 | #include <linux/debugfs.h> | |
73bc256d | 7 | #include <linux/export.h> |
bba90760 | 8 | #include <linux/spinlock.h> |
75dcfc1d | 9 | #include <asm/debug.h> |
bba90760 DD |
10 | |
11 | static int ss_get(void *data, u64 *val) | |
12 | { | |
13 | ktime_t start, finish; | |
14 | int loops; | |
15 | int cont; | |
16 | DEFINE_RAW_SPINLOCK(ss_spin); | |
17 | ||
18 | loops = 1000000; | |
19 | cont = 1; | |
20 | ||
21 | start = ktime_get(); | |
22 | ||
23 | while (cont) { | |
24 | raw_spin_lock(&ss_spin); | |
25 | loops--; | |
26 | if (loops == 0) | |
27 | cont = 0; | |
28 | raw_spin_unlock(&ss_spin); | |
29 | } | |
30 | ||
31 | finish = ktime_get(); | |
32 | ||
33 | *val = ktime_us_delta(finish, start); | |
34 | ||
35 | return 0; | |
36 | } | |
37 | ||
63d6c981 | 38 | DEFINE_DEBUGFS_ATTRIBUTE(fops_ss, ss_get, NULL, "%llu\n"); |
bba90760 DD |
39 | |
40 | ||
41 | ||
42 | struct spin_multi_state { | |
43 | raw_spinlock_t lock; | |
44 | atomic_t start_wait; | |
45 | atomic_t enter_wait; | |
46 | atomic_t exit_wait; | |
47 | int loops; | |
48 | }; | |
49 | ||
50 | struct spin_multi_per_thread { | |
51 | struct spin_multi_state *state; | |
52 | ktime_t start; | |
53 | }; | |
54 | ||
55 | static int multi_other(void *data) | |
56 | { | |
57 | int loops; | |
58 | int cont; | |
59 | struct spin_multi_per_thread *pt = data; | |
60 | struct spin_multi_state *s = pt->state; | |
61 | ||
62 | loops = s->loops; | |
63 | cont = 1; | |
64 | ||
65 | atomic_dec(&s->enter_wait); | |
66 | ||
67 | while (atomic_read(&s->enter_wait)) | |
68 | ; /* spin */ | |
69 | ||
70 | pt->start = ktime_get(); | |
71 | ||
72 | atomic_dec(&s->start_wait); | |
73 | ||
74 | while (atomic_read(&s->start_wait)) | |
75 | ; /* spin */ | |
76 | ||
77 | while (cont) { | |
78 | raw_spin_lock(&s->lock); | |
79 | loops--; | |
80 | if (loops == 0) | |
81 | cont = 0; | |
82 | raw_spin_unlock(&s->lock); | |
83 | } | |
84 | ||
85 | atomic_dec(&s->exit_wait); | |
86 | while (atomic_read(&s->exit_wait)) | |
87 | ; /* spin */ | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static int multi_get(void *data, u64 *val) | |
92 | { | |
93 | ktime_t finish; | |
94 | struct spin_multi_state ms; | |
95 | struct spin_multi_per_thread t1, t2; | |
96 | ||
97 | ms.lock = __RAW_SPIN_LOCK_UNLOCKED("multi_get"); | |
98 | ms.loops = 1000000; | |
99 | ||
100 | atomic_set(&ms.start_wait, 2); | |
101 | atomic_set(&ms.enter_wait, 2); | |
102 | atomic_set(&ms.exit_wait, 2); | |
103 | t1.state = &ms; | |
104 | t2.state = &ms; | |
105 | ||
106 | kthread_run(multi_other, &t2, "multi_get"); | |
107 | ||
108 | multi_other(&t1); | |
109 | ||
110 | finish = ktime_get(); | |
111 | ||
112 | *val = ktime_us_delta(finish, t1.start); | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
63d6c981 | 117 | DEFINE_DEBUGFS_ATTRIBUTE(fops_multi, multi_get, NULL, "%llu\n"); |
bba90760 | 118 | |
bba90760 DD |
119 | static int __init spinlock_test(void) |
120 | { | |
63d6c981 | 121 | debugfs_create_file_unsafe("spin_single", S_IRUGO, mips_debugfs_dir, NULL, |
d8140426 | 122 | &fops_ss); |
63d6c981 | 123 | debugfs_create_file_unsafe("spin_multi", S_IRUGO, mips_debugfs_dir, NULL, |
d8140426 | 124 | &fops_multi); |
bba90760 DD |
125 | return 0; |
126 | } | |
127 | device_initcall(spinlock_test); |