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Commit | Line | Data |
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5033cba0 | 1 | /* |
62a31a03 | 2 | * Architecture specific (i386/x86_64) functions for kexec based crash dumps. |
5033cba0 EB |
3 | * |
4 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) | |
5 | * | |
6 | * Copyright (C) IBM Corporation, 2004. All rights reserved. | |
7 | * | |
8 | */ | |
9 | ||
10 | #include <linux/init.h> | |
11 | #include <linux/types.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/smp.h> | |
5033cba0 EB |
14 | #include <linux/reboot.h> |
15 | #include <linux/kexec.h> | |
5033cba0 EB |
16 | #include <linux/delay.h> |
17 | #include <linux/elf.h> | |
18 | #include <linux/elfcore.h> | |
19 | ||
20 | #include <asm/processor.h> | |
21 | #include <asm/hardirq.h> | |
22 | #include <asm/nmi.h> | |
23 | #include <asm/hw_irq.h> | |
19842d67 | 24 | #include <asm/apic.h> |
0c1b2724 | 25 | #include <asm/hpet.h> |
1eeb66a1 | 26 | #include <linux/kdebug.h> |
ce53af94 | 27 | #include <asm/smp.h> |
2fbe7b25 | 28 | |
c4ac4263 | 29 | #include <mach_ipi.h> |
5033cba0 | 30 | |
a3ea8ac8 VG |
31 | /* This keeps a track of which one is crashing cpu. */ |
32 | static int crashing_cpu; | |
5033cba0 | 33 | |
e78a887a | 34 | #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) |
c4ac4263 EB |
35 | static atomic_t waiting_for_crash_ipi; |
36 | ||
2fbe7b25 DZ |
37 | static int crash_nmi_callback(struct notifier_block *self, |
38 | unsigned long val, void *data) | |
c4ac4263 | 39 | { |
2fbe7b25 | 40 | struct pt_regs *regs; |
1fb473d8 | 41 | #ifdef CONFIG_X86_32 |
4d55476c | 42 | struct pt_regs fixed_regs; |
62a31a03 | 43 | #endif |
2fbe7b25 DZ |
44 | int cpu; |
45 | ||
260d6790 | 46 | if (val != DIE_NMI_IPI) |
2fbe7b25 DZ |
47 | return NOTIFY_OK; |
48 | ||
49 | regs = ((struct die_args *)data)->regs; | |
50 | cpu = raw_smp_processor_id(); | |
a3ea8ac8 VG |
51 | |
52 | /* Don't do anything if this handler is invoked on crashing cpu. | |
53 | * Otherwise, system will completely hang. Crashing cpu can get | |
54 | * an NMI if system was initially booted with nmi_watchdog parameter. | |
55 | */ | |
56 | if (cpu == crashing_cpu) | |
260d6790 | 57 | return NOTIFY_STOP; |
c4ac4263 | 58 | local_irq_disable(); |
4d55476c | 59 | |
1fb473d8 | 60 | #ifdef CONFIG_X86_32 |
db753bdf | 61 | if (!user_mode_vm(regs)) { |
e996e581 | 62 | crash_fixup_ss_esp(&fixed_regs, regs); |
4d55476c VG |
63 | regs = &fixed_regs; |
64 | } | |
62a31a03 | 65 | #endif |
85916f81 | 66 | crash_save_cpu(regs, cpu); |
19842d67 | 67 | disable_local_APIC(); |
c4ac4263 EB |
68 | atomic_dec(&waiting_for_crash_ipi); |
69 | /* Assume hlt works */ | |
f2ab4461 | 70 | halt(); |
caad3c2a CE |
71 | for (;;) |
72 | cpu_relax(); | |
72414d3f | 73 | |
c4ac4263 EB |
74 | return 1; |
75 | } | |
76 | ||
c4ac4263 EB |
77 | static void smp_send_nmi_allbutself(void) |
78 | { | |
bc03613d FV |
79 | cpumask_t mask = cpu_online_map; |
80 | cpu_clear(safe_smp_processor_id(), mask); | |
81 | if (!cpus_empty(mask)) | |
82 | send_IPI_mask(mask, NMI_VECTOR); | |
c4ac4263 EB |
83 | } |
84 | ||
2fbe7b25 DZ |
85 | static struct notifier_block crash_nmi_nb = { |
86 | .notifier_call = crash_nmi_callback, | |
87 | }; | |
88 | ||
c4ac4263 EB |
89 | static void nmi_shootdown_cpus(void) |
90 | { | |
91 | unsigned long msecs; | |
c4ac4263 | 92 | |
72414d3f | 93 | atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); |
c4ac4263 | 94 | /* Would it be better to replace the trap vector here? */ |
2fbe7b25 DZ |
95 | if (register_die_notifier(&crash_nmi_nb)) |
96 | return; /* return what? */ | |
c4ac4263 EB |
97 | /* Ensure the new callback function is set before sending |
98 | * out the NMI | |
99 | */ | |
100 | wmb(); | |
101 | ||
102 | smp_send_nmi_allbutself(); | |
103 | ||
104 | msecs = 1000; /* Wait at most a second for the other cpus to stop */ | |
105 | while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { | |
106 | mdelay(1); | |
107 | msecs--; | |
108 | } | |
109 | ||
110 | /* Leave the nmi callback set */ | |
19842d67 | 111 | disable_local_APIC(); |
c4ac4263 EB |
112 | } |
113 | #else | |
114 | static void nmi_shootdown_cpus(void) | |
115 | { | |
116 | /* There are no cpus to shootdown */ | |
117 | } | |
118 | #endif | |
119 | ||
6e274d14 | 120 | void machine_crash_shutdown(struct pt_regs *regs) |
5033cba0 EB |
121 | { |
122 | /* This function is only called after the system | |
f18190bd | 123 | * has panicked or is otherwise in a critical state. |
5033cba0 EB |
124 | * The minimum amount of code to allow a kexec'd kernel |
125 | * to run successfully needs to happen here. | |
126 | * | |
127 | * In practice this means shooting down the other cpus in | |
128 | * an SMP system. | |
129 | */ | |
c4ac4263 EB |
130 | /* The kernel is broken so disable interrupts */ |
131 | local_irq_disable(); | |
a3ea8ac8 VG |
132 | |
133 | /* Make a note of crashing cpu. Will be used in NMI callback.*/ | |
ce53af94 | 134 | crashing_cpu = safe_smp_processor_id(); |
c4ac4263 | 135 | nmi_shootdown_cpus(); |
19842d67 VG |
136 | lapic_shutdown(); |
137 | #if defined(CONFIG_X86_IO_APIC) | |
138 | disable_IO_APIC(); | |
0c1b2724 OH |
139 | #endif |
140 | #ifdef CONFIG_HPET_TIMER | |
141 | hpet_disable(); | |
19842d67 | 142 | #endif |
85916f81 | 143 | crash_save_cpu(regs, safe_smp_processor_id()); |
5033cba0 | 144 | } |