Commit | Line | Data |
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99e8b9ca DZ |
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 | test_nmi_ipi(to_cpumask(nmi_ipi_mask)); | |
94 | } | |
95 | ||
96 | static void local_ipi(void) | |
97 | { | |
98 | cpumask_clear(to_cpumask(nmi_ipi_mask)); | |
99 | cpumask_set_cpu(smp_processor_id(), to_cpumask(nmi_ipi_mask)); | |
100 | test_nmi_ipi(to_cpumask(nmi_ipi_mask)); | |
101 | } | |
102 | ||
103 | static void reset_nmi(void) | |
104 | { | |
105 | nmi_fail = 0; | |
106 | } | |
107 | ||
108 | static void dotest(void (*testcase_fn)(void), int expected) | |
109 | { | |
110 | testcase_fn(); | |
111 | /* | |
112 | * Filter out expected failures: | |
113 | */ | |
114 | if (nmi_fail != expected) { | |
115 | unexpected_testcase_failures++; | |
116 | ||
117 | if (nmi_fail == FAILURE) | |
118 | printk("FAILED |"); | |
119 | else if (nmi_fail == TIMEOUT) | |
120 | printk("TIMEOUT|"); | |
121 | else | |
122 | printk("ERROR |"); | |
123 | dump_stack(); | |
124 | } else { | |
125 | testcase_successes++; | |
126 | printk(" ok |"); | |
127 | } | |
128 | testcase_total++; | |
129 | ||
130 | reset_nmi(); | |
131 | } | |
132 | ||
133 | static inline void print_testname(const char *testname) | |
134 | { | |
135 | printk("%12s:", testname); | |
136 | } | |
137 | ||
138 | void nmi_selftest(void) | |
139 | { | |
140 | init_nmi_testsuite(); | |
141 | ||
142 | /* | |
143 | * Run the testsuite: | |
144 | */ | |
145 | printk("----------------\n"); | |
146 | printk("| NMI testsuite:\n"); | |
147 | printk("--------------------\n"); | |
148 | ||
149 | print_testname("remote IPI"); | |
150 | dotest(remote_ipi, SUCCESS); | |
151 | printk("\n"); | |
152 | print_testname("local IPI"); | |
153 | dotest(local_ipi, SUCCESS); | |
154 | printk("\n"); | |
155 | ||
156 | cleanup_nmi_testsuite(); | |
157 | ||
158 | if (unexpected_testcase_failures) { | |
159 | printk("--------------------\n"); | |
160 | printk("BUG: %3d unexpected failures (out of %3d) - debugging disabled! |\n", | |
161 | unexpected_testcase_failures, testcase_total); | |
162 | printk("-----------------------------------------------------------------\n"); | |
163 | } else if (expected_testcase_failures && testcase_successes) { | |
164 | printk("--------------------\n"); | |
165 | printk("%3d out of %3d testcases failed, as expected. |\n", | |
166 | expected_testcase_failures, testcase_total); | |
167 | printk("----------------------------------------------------\n"); | |
168 | } else if (expected_testcase_failures && !testcase_successes) { | |
169 | printk("--------------------\n"); | |
170 | printk("All %3d testcases failed, as expected. |\n", | |
171 | expected_testcase_failures); | |
172 | printk("----------------------------------------\n"); | |
173 | } else { | |
174 | printk("--------------------\n"); | |
175 | printk("Good, all %3d testcases passed! |\n", | |
176 | testcase_successes); | |
177 | printk("---------------------------------\n"); | |
178 | } | |
179 | } |