Commit | Line | Data |
---|---|---|
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> |
ed23dc6f | 28 | #include <asm/reboot.h> |
2fbe7b25 | 29 | |
c4ac4263 | 30 | #include <mach_ipi.h> |
5033cba0 | 31 | |
a3ea8ac8 VG |
32 | /* This keeps a track of which one is crashing cpu. */ |
33 | static int crashing_cpu; | |
5033cba0 | 34 | |
e78a887a | 35 | #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) |
c4ac4263 EB |
36 | static atomic_t waiting_for_crash_ipi; |
37 | ||
2fbe7b25 DZ |
38 | static int crash_nmi_callback(struct notifier_block *self, |
39 | unsigned long val, void *data) | |
c4ac4263 | 40 | { |
2fbe7b25 | 41 | struct pt_regs *regs; |
1fb473d8 | 42 | #ifdef CONFIG_X86_32 |
4d55476c | 43 | struct pt_regs fixed_regs; |
62a31a03 | 44 | #endif |
2fbe7b25 DZ |
45 | int cpu; |
46 | ||
260d6790 | 47 | if (val != DIE_NMI_IPI) |
2fbe7b25 DZ |
48 | return NOTIFY_OK; |
49 | ||
50 | regs = ((struct die_args *)data)->regs; | |
51 | cpu = raw_smp_processor_id(); | |
a3ea8ac8 VG |
52 | |
53 | /* Don't do anything if this handler is invoked on crashing cpu. | |
54 | * Otherwise, system will completely hang. Crashing cpu can get | |
55 | * an NMI if system was initially booted with nmi_watchdog parameter. | |
56 | */ | |
57 | if (cpu == crashing_cpu) | |
260d6790 | 58 | return NOTIFY_STOP; |
c4ac4263 | 59 | local_irq_disable(); |
4d55476c | 60 | |
1fb473d8 | 61 | #ifdef CONFIG_X86_32 |
db753bdf | 62 | if (!user_mode_vm(regs)) { |
e996e581 | 63 | crash_fixup_ss_esp(&fixed_regs, regs); |
4d55476c VG |
64 | regs = &fixed_regs; |
65 | } | |
62a31a03 | 66 | #endif |
85916f81 | 67 | crash_save_cpu(regs, cpu); |
19842d67 | 68 | disable_local_APIC(); |
c4ac4263 EB |
69 | atomic_dec(&waiting_for_crash_ipi); |
70 | /* Assume hlt works */ | |
f2ab4461 | 71 | halt(); |
caad3c2a CE |
72 | for (;;) |
73 | cpu_relax(); | |
72414d3f | 74 | |
c4ac4263 EB |
75 | return 1; |
76 | } | |
77 | ||
c4ac4263 EB |
78 | static void smp_send_nmi_allbutself(void) |
79 | { | |
bc03613d FV |
80 | cpumask_t mask = cpu_online_map; |
81 | cpu_clear(safe_smp_processor_id(), mask); | |
82 | if (!cpus_empty(mask)) | |
83 | send_IPI_mask(mask, NMI_VECTOR); | |
c4ac4263 EB |
84 | } |
85 | ||
2fbe7b25 DZ |
86 | static struct notifier_block crash_nmi_nb = { |
87 | .notifier_call = crash_nmi_callback, | |
88 | }; | |
89 | ||
c4ac4263 EB |
90 | static void nmi_shootdown_cpus(void) |
91 | { | |
92 | unsigned long msecs; | |
c4ac4263 | 93 | |
72414d3f | 94 | atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); |
c4ac4263 | 95 | /* Would it be better to replace the trap vector here? */ |
2fbe7b25 DZ |
96 | if (register_die_notifier(&crash_nmi_nb)) |
97 | return; /* return what? */ | |
c4ac4263 EB |
98 | /* Ensure the new callback function is set before sending |
99 | * out the NMI | |
100 | */ | |
101 | wmb(); | |
102 | ||
103 | smp_send_nmi_allbutself(); | |
104 | ||
105 | msecs = 1000; /* Wait at most a second for the other cpus to stop */ | |
106 | while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { | |
107 | mdelay(1); | |
108 | msecs--; | |
109 | } | |
110 | ||
111 | /* Leave the nmi callback set */ | |
19842d67 | 112 | disable_local_APIC(); |
c4ac4263 EB |
113 | } |
114 | #else | |
115 | static void nmi_shootdown_cpus(void) | |
116 | { | |
117 | /* There are no cpus to shootdown */ | |
118 | } | |
119 | #endif | |
120 | ||
ed23dc6f | 121 | void native_machine_crash_shutdown(struct pt_regs *regs) |
5033cba0 EB |
122 | { |
123 | /* This function is only called after the system | |
f18190bd | 124 | * has panicked or is otherwise in a critical state. |
5033cba0 EB |
125 | * The minimum amount of code to allow a kexec'd kernel |
126 | * to run successfully needs to happen here. | |
127 | * | |
128 | * In practice this means shooting down the other cpus in | |
129 | * an SMP system. | |
130 | */ | |
c4ac4263 EB |
131 | /* The kernel is broken so disable interrupts */ |
132 | local_irq_disable(); | |
a3ea8ac8 VG |
133 | |
134 | /* Make a note of crashing cpu. Will be used in NMI callback.*/ | |
ce53af94 | 135 | crashing_cpu = safe_smp_processor_id(); |
c4ac4263 | 136 | nmi_shootdown_cpus(); |
19842d67 VG |
137 | lapic_shutdown(); |
138 | #if defined(CONFIG_X86_IO_APIC) | |
139 | disable_IO_APIC(); | |
0c1b2724 OH |
140 | #endif |
141 | #ifdef CONFIG_HPET_TIMER | |
142 | hpet_disable(); | |
19842d67 | 143 | #endif |
85916f81 | 144 | crash_save_cpu(regs, safe_smp_processor_id()); |
5033cba0 | 145 | } |