diff options
Diffstat (limited to 'arch/x86/kernel/nmi_selftest.c')
-rw-r--r-- | arch/x86/kernel/nmi_selftest.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/arch/x86/kernel/nmi_selftest.c b/arch/x86/kernel/nmi_selftest.c new file mode 100644 index 000000000000..0d01a8ea4e11 --- /dev/null +++ b/arch/x86/kernel/nmi_selftest.c | |||
@@ -0,0 +1,180 @@ | |||
1 | /* | ||
2 | * arch/x86/kernel/nmi-selftest.c | ||
3 | * | ||
4 | * Testsuite for NMI: IPIs | ||
5 | * | ||
6 | * Started by Don Zickus: | ||
7 | * (using lib/locking-selftest.c as a guide) | ||
8 | * | ||
9 | * Copyright (C) 2011 Red Hat, Inc., Don Zickus <dzickus@redhat.com> | ||
10 | */ | ||
11 | |||
12 | #include <linux/smp.h> | ||
13 | #include <linux/cpumask.h> | ||
14 | #include <linux/delay.h> | ||
15 | |||
16 | #include <asm/apic.h> | ||
17 | #include <asm/nmi.h> | ||
18 | |||
19 | #define SUCCESS 0 | ||
20 | #define FAILURE 1 | ||
21 | #define TIMEOUT 2 | ||
22 | |||
23 | static int nmi_fail; | ||
24 | |||
25 | /* check to see if NMI IPIs work on this machine */ | ||
26 | static DECLARE_BITMAP(nmi_ipi_mask, NR_CPUS) __read_mostly; | ||
27 | |||
28 | static int testcase_total; | ||
29 | static int testcase_successes; | ||
30 | static int expected_testcase_failures; | ||
31 | static int unexpected_testcase_failures; | ||
32 | static int unexpected_testcase_unknowns; | ||
33 | |||
34 | static int nmi_unk_cb(unsigned int val, struct pt_regs *regs) | ||
35 | { | ||
36 | unexpected_testcase_unknowns++; | ||
37 | return NMI_HANDLED; | ||
38 | } | ||
39 | |||
40 | static void init_nmi_testsuite(void) | ||
41 | { | ||
42 | /* trap all the unknown NMIs we may generate */ | ||
43 | register_nmi_handler(NMI_UNKNOWN, nmi_unk_cb, 0, "nmi_selftest_unk"); | ||
44 | } | ||
45 | |||
46 | static void cleanup_nmi_testsuite(void) | ||
47 | { | ||
48 | unregister_nmi_handler(NMI_UNKNOWN, "nmi_selftest_unk"); | ||
49 | } | ||
50 | |||
51 | static int test_nmi_ipi_callback(unsigned int val, struct pt_regs *regs) | ||
52 | { | ||
53 | int cpu = raw_smp_processor_id(); | ||
54 | |||
55 | if (cpumask_test_and_clear_cpu(cpu, to_cpumask(nmi_ipi_mask))) | ||
56 | return NMI_HANDLED; | ||
57 | |||
58 | return NMI_DONE; | ||
59 | } | ||
60 | |||
61 | static void test_nmi_ipi(struct cpumask *mask) | ||
62 | { | ||
63 | unsigned long timeout; | ||
64 | |||
65 | if (register_nmi_handler(NMI_LOCAL, test_nmi_ipi_callback, | ||
66 | NMI_FLAG_FIRST, "nmi_selftest")) { | ||
67 | nmi_fail = FAILURE; | ||
68 | return; | ||
69 | } | ||
70 | |||
71 | /* sync above data before sending NMI */ | ||
72 | wmb(); | ||
73 | |||
74 | apic->send_IPI_mask(mask, NMI_VECTOR); | ||
75 | |||
76 | /* Don't wait longer than a second */ | ||
77 | timeout = USEC_PER_SEC; | ||
78 | while (!cpumask_empty(mask) && timeout--) | ||
79 | udelay(1); | ||
80 | |||
81 | /* What happens if we timeout, do we still unregister?? */ | ||
82 | unregister_nmi_handler(NMI_LOCAL, "nmi_selftest"); | ||
83 | |||
84 | if (!timeout) | ||
85 | nmi_fail = TIMEOUT; | ||
86 | return; | ||
87 | } | ||
88 | |||
89 | static void remote_ipi(void) | ||
90 | { | ||
91 | cpumask_copy(to_cpumask(nmi_ipi_mask), cpu_online_mask); | ||
92 | cpumask_clear_cpu(smp_processor_id(), to_cpumask(nmi_ipi_mask)); | ||
93 | if (!cpumask_empty(to_cpumask(nmi_ipi_mask))) | ||
94 | test_nmi_ipi(to_cpumask(nmi_ipi_mask)); | ||
95 | } | ||
96 | |||
97 | static void local_ipi(void) | ||
98 | { | ||
99 | cpumask_clear(to_cpumask(nmi_ipi_mask)); | ||
100 | cpumask_set_cpu(smp_processor_id(), to_cpumask(nmi_ipi_mask)); | ||
101 | test_nmi_ipi(to_cpumask(nmi_ipi_mask)); | ||
102 | } | ||
103 | |||
104 | static void reset_nmi(void) | ||
105 | { | ||
106 | nmi_fail = 0; | ||
107 | } | ||
108 | |||
109 | static void dotest(void (*testcase_fn)(void), int expected) | ||
110 | { | ||
111 | testcase_fn(); | ||
112 | /* | ||
113 | * Filter out expected failures: | ||
114 | */ | ||
115 | if (nmi_fail != expected) { | ||
116 | unexpected_testcase_failures++; | ||
117 | |||
118 | if (nmi_fail == FAILURE) | ||
119 | printk("FAILED |"); | ||
120 | else if (nmi_fail == TIMEOUT) | ||
121 | printk("TIMEOUT|"); | ||
122 | else | ||
123 | printk("ERROR |"); | ||
124 | dump_stack(); | ||
125 | } else { | ||
126 | testcase_successes++; | ||
127 | printk(" ok |"); | ||
128 | } | ||
129 | testcase_total++; | ||
130 | |||
131 | reset_nmi(); | ||
132 | } | ||
133 | |||
134 | static inline void print_testname(const char *testname) | ||
135 | { | ||
136 | printk("%12s:", testname); | ||
137 | } | ||
138 | |||
139 | void nmi_selftest(void) | ||
140 | { | ||
141 | init_nmi_testsuite(); | ||
142 | |||
143 | /* | ||
144 | * Run the testsuite: | ||
145 | */ | ||
146 | printk("----------------\n"); | ||
147 | printk("| NMI testsuite:\n"); | ||
148 | printk("--------------------\n"); | ||
149 | |||
150 | print_testname("remote IPI"); | ||
151 | dotest(remote_ipi, SUCCESS); | ||
152 | printk("\n"); | ||
153 | print_testname("local IPI"); | ||
154 | dotest(local_ipi, SUCCESS); | ||
155 | printk("\n"); | ||
156 | |||
157 | cleanup_nmi_testsuite(); | ||
158 | |||
159 | if (unexpected_testcase_failures) { | ||
160 | printk("--------------------\n"); | ||
161 | printk("BUG: %3d unexpected failures (out of %3d) - debugging disabled! |\n", | ||
162 | unexpected_testcase_failures, testcase_total); | ||
163 | printk("-----------------------------------------------------------------\n"); | ||
164 | } else if (expected_testcase_failures && testcase_successes) { | ||
165 | printk("--------------------\n"); | ||
166 | printk("%3d out of %3d testcases failed, as expected. |\n", | ||
167 | expected_testcase_failures, testcase_total); | ||
168 | printk("----------------------------------------------------\n"); | ||
169 | } else if (expected_testcase_failures && !testcase_successes) { | ||
170 | printk("--------------------\n"); | ||
171 | printk("All %3d testcases failed, as expected. |\n", | ||
172 | expected_testcase_failures); | ||
173 | printk("----------------------------------------\n"); | ||
174 | } else { | ||
175 | printk("--------------------\n"); | ||
176 | printk("Good, all %3d testcases passed! |\n", | ||
177 | testcase_successes); | ||
178 | printk("---------------------------------\n"); | ||
179 | } | ||
180 | } | ||