1 /* 2 * arch/ia64/kernel/crash.c 3 * 4 * Architecture specific (ia64) functions for kexec based crash dumps. 5 * 6 * Created by: Khalid Aziz <khalid.aziz@hp.com> 7 * Copyright (C) 2005 Hewlett-Packard Development Company, L.P. 8 * Copyright (C) 2005 Intel Corp Zou Nan hai <nanhai.zou@intel.com> 9 * 10 */ 11 #include <linux/smp.h> 12 #include <linux/delay.h> 13 #include <linux/crash_dump.h> 14 #include <linux/bootmem.h> 15 #include <linux/kexec.h> 16 #include <linux/elfcore.h> 17 #include <linux/sysctl.h> 18 #include <linux/init.h> 19 #include <linux/kdebug.h> 20 21 #include <asm/mca.h> 22 23 int kdump_status[NR_CPUS]; 24 static atomic_t kdump_cpu_frozen; 25 atomic_t kdump_in_progress; 26 static int kdump_on_init = 1; 27 static int kdump_on_fatal_mca = 1; 28 29 static inline Elf64_Word 30 *append_elf_note(Elf64_Word *buf, char *name, unsigned type, void *data, 31 size_t data_len) 32 { 33 struct elf_note *note = (struct elf_note *)buf; 34 note->n_namesz = strlen(name) + 1; 35 note->n_descsz = data_len; 36 note->n_type = type; 37 buf += (sizeof(*note) + 3)/4; 38 memcpy(buf, name, note->n_namesz); 39 buf += (note->n_namesz + 3)/4; 40 memcpy(buf, data, data_len); 41 buf += (data_len + 3)/4; 42 return buf; 43 } 44 45 static void 46 final_note(void *buf) 47 { 48 memset(buf, 0, sizeof(struct elf_note)); 49 } 50 51 extern void ia64_dump_cpu_regs(void *); 52 53 static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus); 54 55 void 56 crash_save_this_cpu(void) 57 { 58 void *buf; 59 unsigned long cfm, sof, sol; 60 61 int cpu = smp_processor_id(); 62 struct elf_prstatus *prstatus = &per_cpu(elf_prstatus, cpu); 63 64 elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg); 65 memset(prstatus, 0, sizeof(*prstatus)); 66 prstatus->pr_pid = current->pid; 67 68 ia64_dump_cpu_regs(dst); 69 cfm = dst[43]; 70 sol = (cfm >> 7) & 0x7f; 71 sof = cfm & 0x7f; 72 dst[46] = (unsigned long)ia64_rse_skip_regs((unsigned long *)dst[46], 73 sof - sol); 74 75 buf = (u64 *) per_cpu_ptr(crash_notes, cpu); 76 if (!buf) 77 return; 78 buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, prstatus, 79 sizeof(*prstatus)); 80 final_note(buf); 81 } 82 83 #ifdef CONFIG_SMP 84 static int 85 kdump_wait_cpu_freeze(void) 86 { 87 int cpu_num = num_online_cpus() - 1; 88 int timeout = 1000; 89 while(timeout-- > 0) { 90 if (atomic_read(&kdump_cpu_frozen) == cpu_num) 91 return 0; 92 udelay(1000); 93 } 94 return 1; 95 } 96 #endif 97 98 void 99 machine_crash_shutdown(struct pt_regs *pt) 100 { 101 /* This function is only called after the system 102 * has paniced or is otherwise in a critical state. 103 * The minimum amount of code to allow a kexec'd kernel 104 * to run successfully needs to happen here. 105 * 106 * In practice this means shooting down the other cpus in 107 * an SMP system. 108 */ 109 kexec_disable_iosapic(); 110 #ifdef CONFIG_SMP 111 kdump_smp_send_stop(); 112 /* not all cpu response to IPI, send INIT to freeze them */ 113 if (kdump_wait_cpu_freeze() && kdump_on_init) { 114 kdump_smp_send_init(); 115 } 116 #endif 117 } 118 119 static void 120 machine_kdump_on_init(void) 121 { 122 crash_save_vmcoreinfo(); 123 local_irq_disable(); 124 kexec_disable_iosapic(); 125 machine_kexec(ia64_kimage); 126 } 127 128 void 129 kdump_cpu_freeze(struct unw_frame_info *info, void *arg) 130 { 131 int cpuid; 132 local_irq_disable(); 133 cpuid = smp_processor_id(); 134 crash_save_this_cpu(); 135 current->thread.ksp = (__u64)info->sw - 16; 136 atomic_inc(&kdump_cpu_frozen); 137 kdump_status[cpuid] = 1; 138 mb(); 139 #ifdef CONFIG_HOTPLUG_CPU 140 if (cpuid != 0) 141 ia64_jump_to_sal(&sal_boot_rendez_state[cpuid]); 142 #endif 143 for (;;) 144 cpu_relax(); 145 } 146 147 static int 148 kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data) 149 { 150 struct ia64_mca_notify_die *nd; 151 struct die_args *args = data; 152 153 if (!kdump_on_init && !kdump_on_fatal_mca) 154 return NOTIFY_DONE; 155 156 if (!ia64_kimage) { 157 if (val == DIE_INIT_MONARCH_LEAVE) 158 ia64_mca_printk(KERN_NOTICE 159 "%s: kdump not configured\n", 160 __func__); 161 return NOTIFY_DONE; 162 } 163 164 if (val != DIE_INIT_MONARCH_LEAVE && 165 val != DIE_INIT_SLAVE_LEAVE && 166 val != DIE_INIT_MONARCH_PROCESS && 167 val != DIE_MCA_RENDZVOUS_LEAVE && 168 val != DIE_MCA_MONARCH_LEAVE) 169 return NOTIFY_DONE; 170 171 nd = (struct ia64_mca_notify_die *)args->err; 172 /* Reason code 1 means machine check rendezvous*/ 173 if ((val == DIE_INIT_MONARCH_LEAVE || val == DIE_INIT_SLAVE_LEAVE 174 || val == DIE_INIT_MONARCH_PROCESS) && nd->sos->rv_rc == 1) 175 return NOTIFY_DONE; 176 177 switch (val) { 178 case DIE_INIT_MONARCH_PROCESS: 179 if (kdump_on_init) { 180 atomic_set(&kdump_in_progress, 1); 181 *(nd->monarch_cpu) = -1; 182 } 183 break; 184 case DIE_INIT_MONARCH_LEAVE: 185 if (kdump_on_init) 186 machine_kdump_on_init(); 187 break; 188 case DIE_INIT_SLAVE_LEAVE: 189 if (atomic_read(&kdump_in_progress)) 190 unw_init_running(kdump_cpu_freeze, NULL); 191 break; 192 case DIE_MCA_RENDZVOUS_LEAVE: 193 if (atomic_read(&kdump_in_progress)) 194 unw_init_running(kdump_cpu_freeze, NULL); 195 break; 196 case DIE_MCA_MONARCH_LEAVE: 197 /* die_register->signr indicate if MCA is recoverable */ 198 if (kdump_on_fatal_mca && !args->signr) { 199 atomic_set(&kdump_in_progress, 1); 200 *(nd->monarch_cpu) = -1; 201 machine_kdump_on_init(); 202 } 203 break; 204 } 205 return NOTIFY_DONE; 206 } 207 208 #ifdef CONFIG_SYSCTL 209 static ctl_table kdump_ctl_table[] = { 210 { 211 .ctl_name = CTL_UNNUMBERED, 212 .procname = "kdump_on_init", 213 .data = &kdump_on_init, 214 .maxlen = sizeof(int), 215 .mode = 0644, 216 .proc_handler = &proc_dointvec, 217 }, 218 { 219 .ctl_name = CTL_UNNUMBERED, 220 .procname = "kdump_on_fatal_mca", 221 .data = &kdump_on_fatal_mca, 222 .maxlen = sizeof(int), 223 .mode = 0644, 224 .proc_handler = &proc_dointvec, 225 }, 226 { .ctl_name = 0 } 227 }; 228 229 static ctl_table sys_table[] = { 230 { 231 .ctl_name = CTL_KERN, 232 .procname = "kernel", 233 .mode = 0555, 234 .child = kdump_ctl_table, 235 }, 236 { .ctl_name = 0 } 237 }; 238 #endif 239 240 static int 241 machine_crash_setup(void) 242 { 243 /* be notified before default_monarch_init_process */ 244 static struct notifier_block kdump_init_notifier_nb = { 245 .notifier_call = kdump_init_notifier, 246 .priority = 1, 247 }; 248 int ret; 249 if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0) 250 return ret; 251 #ifdef CONFIG_SYSCTL 252 register_sysctl_table(sys_table); 253 #endif 254 return 0; 255 } 256 257 __initcall(machine_crash_setup); 258 259