| 1 | /****************************************************************************** |
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| 2 | * crash.c |
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| 3 | * |
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| 4 | * Based heavily on arch/i386/kernel/crash.c from Linux 2.6.16 |
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| 5 | * |
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| 6 | * Xen port written by: |
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| 7 | * - Simon 'Horms' Horman <horms@verge.net.au> |
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| 8 | * - Magnus Damm <magnus@valinux.co.jp> |
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| 9 | */ |
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| 10 | |
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| 11 | #include <asm/atomic.h> |
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| 12 | #include <asm/elf.h> |
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| 13 | #include <asm/percpu.h> |
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| 14 | #include <xen/types.h> |
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| 15 | #include <xen/irq.h> |
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| 16 | #include <asm/ipi.h> |
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| 17 | #include <asm/nmi.h> |
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| 18 | #include <xen/string.h> |
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| 19 | #include <xen/elf.h> |
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| 20 | #include <xen/elfcore.h> |
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| 21 | #include <xen/smp.h> |
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| 22 | #include <xen/delay.h> |
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| 23 | #include <xen/perfc.h> |
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| 24 | #include <xen/kexec.h> |
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| 25 | #include <xen/sched.h> |
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| 26 | #include <public/xen.h> |
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| 27 | #include <asm/shared.h> |
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| 28 | #include <asm/hvm/support.h> |
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| 29 | |
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| 30 | static atomic_t waiting_for_crash_ipi; |
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| 31 | static unsigned int crashing_cpu; |
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| 32 | |
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| 33 | static int crash_nmi_callback(struct cpu_user_regs *regs, int cpu) |
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| 34 | { |
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| 35 | /* Don't do anything if this handler is invoked on crashing cpu. |
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| 36 | * Otherwise, system will completely hang. Crashing cpu can get |
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| 37 | * an NMI if system was initially booted with nmi_watchdog parameter. |
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| 38 | */ |
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| 39 | if ( cpu == crashing_cpu ) |
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| 40 | return 1; |
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| 41 | local_irq_disable(); |
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| 42 | |
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| 43 | kexec_crash_save_cpu(); |
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| 44 | disable_local_APIC(); |
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| 45 | atomic_dec(&waiting_for_crash_ipi); |
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| 46 | hvm_disable(); |
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| 47 | |
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| 48 | for ( ; ; ) |
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| 49 | __asm__ __volatile__ ( "hlt" ); |
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| 50 | |
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| 51 | return 1; |
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| 52 | } |
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| 53 | |
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| 54 | /* |
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| 55 | * By using the NMI code instead of a vector we just sneak thru the |
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| 56 | * word generator coming out with just what we want. AND it does |
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| 57 | * not matter if clustered_apic_mode is set or not. |
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| 58 | */ |
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| 59 | static void smp_send_nmi_allbutself(void) |
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| 60 | { |
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| 61 | cpumask_t allbutself = cpu_online_map; |
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| 62 | cpu_clear(smp_processor_id(), allbutself); |
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| 63 | if ( !cpus_empty(allbutself) ) |
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| 64 | send_IPI_mask(allbutself, APIC_DM_NMI); |
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| 65 | } |
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| 66 | |
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| 67 | static void nmi_shootdown_cpus(void) |
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| 68 | { |
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| 69 | unsigned long msecs; |
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| 70 | |
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| 71 | crashing_cpu = smp_processor_id(); |
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| 72 | |
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| 73 | atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); |
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| 74 | /* Would it be better to replace the trap vector here? */ |
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| 75 | set_nmi_callback(crash_nmi_callback); |
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| 76 | /* Ensure the new callback function is set before sending out the NMI. */ |
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| 77 | wmb(); |
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| 78 | |
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| 79 | smp_send_nmi_allbutself(); |
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| 80 | |
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| 81 | msecs = 1000; /* Wait at most a second for the other cpus to stop */ |
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| 82 | while ( (atomic_read(&waiting_for_crash_ipi) > 0) && msecs ) |
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| 83 | { |
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| 84 | mdelay(1); |
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| 85 | msecs--; |
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| 86 | } |
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| 87 | |
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| 88 | /* Leave the nmi callback set */ |
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| 89 | disable_local_APIC(); |
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| 90 | } |
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| 91 | |
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| 92 | void machine_crash_shutdown(void) |
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| 93 | { |
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| 94 | crash_xen_info_t *info; |
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| 95 | |
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| 96 | local_irq_disable(); |
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| 97 | |
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| 98 | nmi_shootdown_cpus(); |
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| 99 | |
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| 100 | disable_IO_APIC(); |
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| 101 | |
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| 102 | hvm_disable(); |
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| 103 | |
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| 104 | info = kexec_crash_save_info(); |
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| 105 | info->dom0_pfn_to_mfn_frame_list_list = |
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| 106 | arch_get_pfn_to_mfn_frame_list_list(dom0); |
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| 107 | } |
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| 108 | |
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| 109 | /* |
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| 110 | * Local variables: |
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| 111 | * mode: C |
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| 112 | * c-set-style: "BSD" |
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| 113 | * c-basic-offset: 4 |
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| 114 | * tab-width: 4 |
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| 115 | * indent-tabs-mode: nil |
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| 116 | * End: |
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| 117 | */ |
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