1 /* 2 * Copyright (C) 2001 Dave Engebretsen IBM Corporation 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 */ 18 19 /* Change Activity: 20 * 2001/09/21 : engebret : Created with minimal EPOW and HW exception support. 21 * End Change Activity 22 */ 23 24 #include <linux/errno.h> 25 #include <linux/threads.h> 26 #include <linux/kernel_stat.h> 27 #include <linux/signal.h> 28 #include <linux/sched.h> 29 #include <linux/ioport.h> 30 #include <linux/interrupt.h> 31 #include <linux/timex.h> 32 #include <linux/init.h> 33 #include <linux/delay.h> 34 #include <linux/irq.h> 35 #include <linux/random.h> 36 #include <linux/sysrq.h> 37 #include <linux/bitops.h> 38 39 #include <asm/uaccess.h> 40 #include <asm/system.h> 41 #include <asm/io.h> 42 #include <asm/pgtable.h> 43 #include <asm/irq.h> 44 #include <asm/cache.h> 45 #include <asm/prom.h> 46 #include <asm/ptrace.h> 47 #include <asm/machdep.h> 48 #include <asm/rtas.h> 49 #include <asm/udbg.h> 50 #include <asm/firmware.h> 51 52 #include "pseries.h" 53 54 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX]; 55 static DEFINE_SPINLOCK(ras_log_buf_lock); 56 57 static char mce_data_buf[RTAS_ERROR_LOG_MAX]; 58 59 static int ras_get_sensor_state_token; 60 static int ras_check_exception_token; 61 62 #define EPOW_SENSOR_TOKEN 9 63 #define EPOW_SENSOR_INDEX 0 64 #define RAS_VECTOR_OFFSET 0x500 65 66 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id); 67 static irqreturn_t ras_error_interrupt(int irq, void *dev_id); 68 69 70 static void request_ras_irqs(struct device_node *np, 71 irq_handler_t handler, 72 const char *name) 73 { 74 int i, index, count = 0; 75 struct of_irq oirq; 76 const u32 *opicprop; 77 unsigned int opicplen; 78 unsigned int virqs[16]; 79 80 /* Check for obsolete "open-pic-interrupt" property. If present, then 81 * map those interrupts using the default interrupt host and default 82 * trigger 83 */ 84 opicprop = of_get_property(np, "open-pic-interrupt", &opicplen); 85 if (opicprop) { 86 opicplen /= sizeof(u32); 87 for (i = 0; i < opicplen; i++) { 88 if (count > 15) 89 break; 90 virqs[count] = irq_create_mapping(NULL, *(opicprop++)); 91 if (virqs[count] == NO_IRQ) 92 printk(KERN_ERR "Unable to allocate interrupt " 93 "number for %s\n", np->full_name); 94 else 95 count++; 96 97 } 98 } 99 /* Else use normal interrupt tree parsing */ 100 else { 101 /* First try to do a proper OF tree parsing */ 102 for (index = 0; of_irq_map_one(np, index, &oirq) == 0; 103 index++) { 104 if (count > 15) 105 break; 106 virqs[count] = irq_create_of_mapping(oirq.controller, 107 oirq.specifier, 108 oirq.size); 109 if (virqs[count] == NO_IRQ) 110 printk(KERN_ERR "Unable to allocate interrupt " 111 "number for %s\n", np->full_name); 112 else 113 count++; 114 } 115 } 116 117 /* Now request them */ 118 for (i = 0; i < count; i++) { 119 if (request_irq(virqs[i], handler, 0, name, NULL)) { 120 printk(KERN_ERR "Unable to request interrupt %d for " 121 "%s\n", virqs[i], np->full_name); 122 return; 123 } 124 } 125 } 126 127 /* 128 * Initialize handlers for the set of interrupts caused by hardware errors 129 * and power system events. 130 */ 131 static int __init init_ras_IRQ(void) 132 { 133 struct device_node *np; 134 135 ras_get_sensor_state_token = rtas_token("get-sensor-state"); 136 ras_check_exception_token = rtas_token("check-exception"); 137 138 /* Internal Errors */ 139 np = of_find_node_by_path("/event-sources/internal-errors"); 140 if (np != NULL) { 141 request_ras_irqs(np, ras_error_interrupt, "RAS_ERROR"); 142 of_node_put(np); 143 } 144 145 /* EPOW Events */ 146 np = of_find_node_by_path("/event-sources/epow-events"); 147 if (np != NULL) { 148 request_ras_irqs(np, ras_epow_interrupt, "RAS_EPOW"); 149 of_node_put(np); 150 } 151 152 return 0; 153 } 154 __initcall(init_ras_IRQ); 155 156 /* 157 * Handle power subsystem events (EPOW). 158 * 159 * Presently we just log the event has occurred. This should be fixed 160 * to examine the type of power failure and take appropriate action where 161 * the time horizon permits something useful to be done. 162 */ 163 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) 164 { 165 int status = 0xdeadbeef; 166 int state = 0; 167 int critical; 168 169 status = rtas_call(ras_get_sensor_state_token, 2, 2, &state, 170 EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX); 171 172 if (state > 3) 173 critical = 1; /* Time Critical */ 174 else 175 critical = 0; 176 177 spin_lock(&ras_log_buf_lock); 178 179 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 180 RAS_VECTOR_OFFSET, 181 irq_map[irq].hwirq, 182 RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS, 183 critical, __pa(&ras_log_buf), 184 rtas_get_error_log_max()); 185 186 udbg_printf("EPOW <0x%lx 0x%x 0x%x>\n", 187 *((unsigned long *)&ras_log_buf), status, state); 188 printk(KERN_WARNING "EPOW <0x%lx 0x%x 0x%x>\n", 189 *((unsigned long *)&ras_log_buf), status, state); 190 191 /* format and print the extended information */ 192 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 193 194 spin_unlock(&ras_log_buf_lock); 195 return IRQ_HANDLED; 196 } 197 198 /* 199 * Handle hardware error interrupts. 200 * 201 * RTAS check-exception is called to collect data on the exception. If 202 * the error is deemed recoverable, we log a warning and return. 203 * For nonrecoverable errors, an error is logged and we stop all processing 204 * as quickly as possible in order to prevent propagation of the failure. 205 */ 206 static irqreturn_t ras_error_interrupt(int irq, void *dev_id) 207 { 208 struct rtas_error_log *rtas_elog; 209 int status = 0xdeadbeef; 210 int fatal; 211 212 spin_lock(&ras_log_buf_lock); 213 214 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 215 RAS_VECTOR_OFFSET, 216 irq_map[irq].hwirq, 217 RTAS_INTERNAL_ERROR, 1 /*Time Critical */, 218 __pa(&ras_log_buf), 219 rtas_get_error_log_max()); 220 221 rtas_elog = (struct rtas_error_log *)ras_log_buf; 222 223 if ((status == 0) && (rtas_elog->severity >= RTAS_SEVERITY_ERROR_SYNC)) 224 fatal = 1; 225 else 226 fatal = 0; 227 228 /* format and print the extended information */ 229 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 230 231 if (fatal) { 232 udbg_printf("Fatal HW Error <0x%lx 0x%x>\n", 233 *((unsigned long *)&ras_log_buf), status); 234 printk(KERN_EMERG "Error: Fatal hardware error <0x%lx 0x%x>\n", 235 *((unsigned long *)&ras_log_buf), status); 236 237 #ifndef DEBUG_RTAS_POWER_OFF 238 /* Don't actually power off when debugging so we can test 239 * without actually failing while injecting errors. 240 * Error data will not be logged to syslog. 241 */ 242 ppc_md.power_off(); 243 #endif 244 } else { 245 udbg_printf("Recoverable HW Error <0x%lx 0x%x>\n", 246 *((unsigned long *)&ras_log_buf), status); 247 printk(KERN_WARNING 248 "Warning: Recoverable hardware error <0x%lx 0x%x>\n", 249 *((unsigned long *)&ras_log_buf), status); 250 } 251 252 spin_unlock(&ras_log_buf_lock); 253 return IRQ_HANDLED; 254 } 255 256 /* Get the error information for errors coming through the 257 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 258 * the actual r3 if possible, and a ptr to the error log entry 259 * will be returned if found. 260 * 261 * The mce_data_buf does not have any locks or protection around it, 262 * if a second machine check comes in, or a system reset is done 263 * before we have logged the error, then we will get corruption in the 264 * error log. This is preferable over holding off on calling 265 * ibm,nmi-interlock which would result in us checkstopping if a 266 * second machine check did come in. 267 */ 268 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 269 { 270 unsigned long errdata = regs->gpr[3]; 271 struct rtas_error_log *errhdr = NULL; 272 unsigned long *savep; 273 274 if ((errdata >= 0x7000 && errdata < 0x7fff0) || 275 (errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) { 276 savep = __va(errdata); 277 regs->gpr[3] = savep[0]; /* restore original r3 */ 278 memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 279 memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX); 280 errhdr = (struct rtas_error_log *)mce_data_buf; 281 } else { 282 printk("FWNMI: corrupt r3\n"); 283 } 284 return errhdr; 285 } 286 287 /* Call this when done with the data returned by FWNMI_get_errinfo. 288 * It will release the saved data area for other CPUs in the 289 * partition to receive FWNMI errors. 290 */ 291 static void fwnmi_release_errinfo(void) 292 { 293 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL); 294 if (ret != 0) 295 printk("FWNMI: nmi-interlock failed: %d\n", ret); 296 } 297 298 int pSeries_system_reset_exception(struct pt_regs *regs) 299 { 300 if (fwnmi_active) { 301 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs); 302 if (errhdr) { 303 /* XXX Should look at FWNMI information */ 304 } 305 fwnmi_release_errinfo(); 306 } 307 return 0; /* need to perform reset */ 308 } 309 310 /* 311 * See if we can recover from a machine check exception. 312 * This is only called on power4 (or above) and only via 313 * the Firmware Non-Maskable Interrupts (fwnmi) handler 314 * which provides the error analysis for us. 315 * 316 * Return 1 if corrected (or delivered a signal). 317 * Return 0 if there is nothing we can do. 318 */ 319 static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err) 320 { 321 int nonfatal = 0; 322 323 if (err->disposition == RTAS_DISP_FULLY_RECOVERED) { 324 /* Platform corrected itself */ 325 nonfatal = 1; 326 } else if ((regs->msr & MSR_RI) && 327 user_mode(regs) && 328 err->severity == RTAS_SEVERITY_ERROR_SYNC && 329 err->disposition == RTAS_DISP_NOT_RECOVERED && 330 err->target == RTAS_TARGET_MEMORY && 331 err->type == RTAS_TYPE_ECC_UNCORR && 332 !(current->pid == 0 || is_global_init(current))) { 333 /* Kill off a user process with an ECC error */ 334 printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n", 335 current->pid); 336 /* XXX something better for ECC error? */ 337 _exception(SIGBUS, regs, BUS_ADRERR, regs->nip); 338 nonfatal = 1; 339 } 340 341 log_error((char *)err, ERR_TYPE_RTAS_LOG, !nonfatal); 342 343 return nonfatal; 344 } 345 346 /* 347 * Handle a machine check. 348 * 349 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 350 * should be present. If so the handler which called us tells us if the 351 * error was recovered (never true if RI=0). 352 * 353 * On hardware prior to Power 4 these exceptions were asynchronous which 354 * means we can't tell exactly where it occurred and so we can't recover. 355 */ 356 int pSeries_machine_check_exception(struct pt_regs *regs) 357 { 358 struct rtas_error_log *errp; 359 360 if (fwnmi_active) { 361 errp = fwnmi_get_errinfo(regs); 362 fwnmi_release_errinfo(); 363 if (errp && recover_mce(regs, errp)) 364 return 1; 365 } 366 367 return 0; 368 } 369