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_freeze_monarch; 27 static int kdump_on_init = 1; 28 static int kdump_on_fatal_mca = 1; 29 30 static inline Elf64_Word 31 *append_elf_note(Elf64_Word *buf, char *name, unsigned type, void *data, 32 size_t data_len) 33 { 34 struct elf_note *note = (struct elf_note *)buf; 35 note->n_namesz = strlen(name) + 1; 36 note->n_descsz = data_len; 37 note->n_type = type; 38 buf += (sizeof(*note) + 3)/4; 39 memcpy(buf, name, note->n_namesz); 40 buf += (note->n_namesz + 3)/4; 41 memcpy(buf, data, data_len); 42 buf += (data_len + 3)/4; 43 return buf; 44 } 45 46 static void 47 final_note(void *buf) 48 { 49 memset(buf, 0, sizeof(struct elf_note)); 50 } 51 52 extern void ia64_dump_cpu_regs(void *); 53 54 static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus); 55 56 void 57 crash_save_this_cpu(void) 58 { 59 void *buf; 60 unsigned long cfm, sof, sol; 61 62 int cpu = smp_processor_id(); 63 struct elf_prstatus *prstatus = &per_cpu(elf_prstatus, cpu); 64 65 elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg); 66 memset(prstatus, 0, sizeof(*prstatus)); 67 prstatus->pr_pid = current->pid; 68 69 ia64_dump_cpu_regs(dst); 70 cfm = dst[43]; 71 sol = (cfm >> 7) & 0x7f; 72 sof = cfm & 0x7f; 73 dst[46] = (unsigned long)ia64_rse_skip_regs((unsigned long *)dst[46], 74 sof - sol); 75 76 buf = (u64 *) per_cpu_ptr(crash_notes, cpu); 77 if (!buf) 78 return; 79 buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, prstatus, 80 sizeof(*prstatus)); 81 final_note(buf); 82 } 83 84 #ifdef CONFIG_SMP 85 static int 86 kdump_wait_cpu_freeze(void) 87 { 88 int cpu_num = num_online_cpus() - 1; 89 int timeout = 1000; 90 while(timeout-- > 0) { 91 if (atomic_read(&kdump_cpu_frozen) == cpu_num) 92 return 0; 93 udelay(1000); 94 } 95 return 1; 96 } 97 #endif 98 99 void 100 machine_crash_shutdown(struct pt_regs *pt) 101 { 102 /* This function is only called after the system 103 * has paniced or is otherwise in a critical state. 104 * The minimum amount of code to allow a kexec'd kernel 105 * to run successfully needs to happen here. 106 * 107 * In practice this means shooting down the other cpus in 108 * an SMP system. 109 */ 110 kexec_disable_iosapic(); 111 #ifdef CONFIG_SMP 112 /* 113 * If kdump_on_init is set and an INIT is asserted here, kdump will 114 * be started again via INIT monarch. 115 */ 116 local_irq_disable(); 117 ia64_set_psr_mc(); /* mask MCA/INIT */ 118 if (atomic_inc_return(&kdump_in_progress) != 1) 119 unw_init_running(kdump_cpu_freeze, NULL); 120 121 /* 122 * Now this cpu is ready for kdump. 123 * Stop all others by IPI or INIT. They could receive INIT from 124 * outside and might be INIT monarch, but only thing they have to 125 * do is falling into kdump_cpu_freeze(). 126 * 127 * If an INIT is asserted here: 128 * - All receivers might be slaves, since some of cpus could already 129 * be frozen and INIT might be masked on monarch. In this case, 130 * all slaves will be frozen soon since kdump_in_progress will let 131 * them into DIE_INIT_SLAVE_LEAVE. 132 * - One might be a monarch, but INIT rendezvous will fail since 133 * at least this cpu already have INIT masked so it never join 134 * to the rendezvous. In this case, all slaves and monarch will 135 * be frozen soon with no wait since the INIT rendezvous is skipped 136 * by kdump_in_progress. 137 */ 138 kdump_smp_send_stop(); 139 /* not all cpu response to IPI, send INIT to freeze them */ 140 if (kdump_wait_cpu_freeze()) { 141 kdump_smp_send_init(); 142 /* wait again, don't go ahead if possible */ 143 kdump_wait_cpu_freeze(); 144 } 145 #endif 146 } 147 148 static void 149 machine_kdump_on_init(void) 150 { 151 crash_save_vmcoreinfo(); 152 local_irq_disable(); 153 kexec_disable_iosapic(); 154 machine_kexec(ia64_kimage); 155 } 156 157 void 158 kdump_cpu_freeze(struct unw_frame_info *info, void *arg) 159 { 160 int cpuid; 161 162 local_irq_disable(); 163 cpuid = smp_processor_id(); 164 crash_save_this_cpu(); 165 current->thread.ksp = (__u64)info->sw - 16; 166 167 ia64_set_psr_mc(); /* mask MCA/INIT and stop reentrance */ 168 169 atomic_inc(&kdump_cpu_frozen); 170 kdump_status[cpuid] = 1; 171 mb(); 172 for (;;) 173 cpu_relax(); 174 } 175 176 static int 177 kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data) 178 { 179 struct ia64_mca_notify_die *nd; 180 struct die_args *args = data; 181 182 if (atomic_read(&kdump_in_progress)) { 183 switch (val) { 184 case DIE_INIT_MONARCH_LEAVE: 185 if (!kdump_freeze_monarch) 186 break; 187 /* fall through */ 188 case DIE_INIT_SLAVE_LEAVE: 189 case DIE_INIT_MONARCH_ENTER: 190 case DIE_MCA_RENDZVOUS_LEAVE: 191 unw_init_running(kdump_cpu_freeze, NULL); 192 break; 193 } 194 } 195 196 if (!kdump_on_init && !kdump_on_fatal_mca) 197 return NOTIFY_DONE; 198 199 if (!ia64_kimage) { 200 if (val == DIE_INIT_MONARCH_LEAVE) 201 ia64_mca_printk(KERN_NOTICE 202 "%s: kdump not configured\n", 203 __func__); 204 return NOTIFY_DONE; 205 } 206 207 if (val != DIE_INIT_MONARCH_LEAVE && 208 val != DIE_INIT_MONARCH_PROCESS && 209 val != DIE_MCA_MONARCH_LEAVE) 210 return NOTIFY_DONE; 211 212 nd = (struct ia64_mca_notify_die *)args->err; 213 214 switch (val) { 215 case DIE_INIT_MONARCH_PROCESS: 216 /* Reason code 1 means machine check rendezvous*/ 217 if (kdump_on_init && (nd->sos->rv_rc != 1)) { 218 if (atomic_inc_return(&kdump_in_progress) != 1) 219 kdump_freeze_monarch = 1; 220 } 221 break; 222 case DIE_INIT_MONARCH_LEAVE: 223 /* Reason code 1 means machine check rendezvous*/ 224 if (kdump_on_init && (nd->sos->rv_rc != 1)) 225 machine_kdump_on_init(); 226 break; 227 case DIE_MCA_MONARCH_LEAVE: 228 /* *(nd->data) indicate if MCA is recoverable */ 229 if (kdump_on_fatal_mca && !(*(nd->data))) { 230 if (atomic_inc_return(&kdump_in_progress) == 1) 231 machine_kdump_on_init(); 232 /* We got fatal MCA while kdump!? No way!! */ 233 } 234 break; 235 } 236 return NOTIFY_DONE; 237 } 238 239 #ifdef CONFIG_SYSCTL 240 static struct ctl_table kdump_ctl_table[] = { 241 { 242 .procname = "kdump_on_init", 243 .data = &kdump_on_init, 244 .maxlen = sizeof(int), 245 .mode = 0644, 246 .proc_handler = proc_dointvec, 247 }, 248 { 249 .procname = "kdump_on_fatal_mca", 250 .data = &kdump_on_fatal_mca, 251 .maxlen = sizeof(int), 252 .mode = 0644, 253 .proc_handler = proc_dointvec, 254 }, 255 { } 256 }; 257 258 static struct ctl_table sys_table[] = { 259 { 260 .procname = "kernel", 261 .mode = 0555, 262 .child = kdump_ctl_table, 263 }, 264 { } 265 }; 266 #endif 267 268 static int 269 machine_crash_setup(void) 270 { 271 /* be notified before default_monarch_init_process */ 272 static struct notifier_block kdump_init_notifier_nb = { 273 .notifier_call = kdump_init_notifier, 274 .priority = 1, 275 }; 276 int ret; 277 if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0) 278 return ret; 279 #ifdef CONFIG_SYSCTL 280 register_sysctl_table(sys_table); 281 #endif 282 return 0; 283 } 284 285 __initcall(machine_crash_setup); 286 287