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/slab.h> 34 #include <linux/delay.h> 35 #include <linux/irq.h> 36 #include <linux/random.h> 37 #include <linux/sysrq.h> 38 #include <linux/bitops.h> 39 40 #include <asm/uaccess.h> 41 #include <asm/system.h> 42 #include <asm/io.h> 43 #include <asm/pgtable.h> 44 #include <asm/irq.h> 45 #include <asm/cache.h> 46 #include <asm/prom.h> 47 #include <asm/ptrace.h> 48 #include <asm/machdep.h> 49 #include <asm/rtas.h> 50 #include <asm/udbg.h> 51 #include <asm/firmware.h> 52 53 #include "pseries.h" 54 55 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX]; 56 static DEFINE_SPINLOCK(ras_log_buf_lock); 57 58 char mce_data_buf[RTAS_ERROR_LOG_MAX]; 59 60 static int ras_get_sensor_state_token; 61 static int ras_check_exception_token; 62 63 #define EPOW_SENSOR_TOKEN 9 64 #define EPOW_SENSOR_INDEX 0 65 #define RAS_VECTOR_OFFSET 0x500 66 67 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id); 68 static irqreturn_t ras_error_interrupt(int irq, void *dev_id); 69 70 71 static void request_ras_irqs(struct device_node *np, 72 irq_handler_t handler, 73 const char *name) 74 { 75 int i, index, count = 0; 76 struct of_irq oirq; 77 const u32 *opicprop; 78 unsigned int opicplen; 79 unsigned int virqs[16]; 80 81 /* Check for obsolete "open-pic-interrupt" property. If present, then 82 * map those interrupts using the default interrupt host and default 83 * trigger 84 */ 85 opicprop = of_get_property(np, "open-pic-interrupt", &opicplen); 86 if (opicprop) { 87 opicplen /= sizeof(u32); 88 for (i = 0; i < opicplen; i++) { 89 if (count > 15) 90 break; 91 virqs[count] = irq_create_mapping(NULL, *(opicprop++)); 92 if (virqs[count] == NO_IRQ) 93 printk(KERN_ERR "Unable to allocate interrupt " 94 "number for %s\n", np->full_name); 95 else 96 count++; 97 98 } 99 } 100 /* Else use normal interrupt tree parsing */ 101 else { 102 /* First try to do a proper OF tree parsing */ 103 for (index = 0; of_irq_map_one(np, index, &oirq) == 0; 104 index++) { 105 if (count > 15) 106 break; 107 virqs[count] = irq_create_of_mapping(oirq.controller, 108 oirq.specifier, 109 oirq.size); 110 if (virqs[count] == NO_IRQ) 111 printk(KERN_ERR "Unable to allocate interrupt " 112 "number for %s\n", np->full_name); 113 else 114 count++; 115 } 116 } 117 118 /* Now request them */ 119 for (i = 0; i < count; i++) { 120 if (request_irq(virqs[i], handler, 0, name, NULL)) { 121 printk(KERN_ERR "Unable to request interrupt %d for " 122 "%s\n", virqs[i], np->full_name); 123 return; 124 } 125 } 126 } 127 128 /* 129 * Initialize handlers for the set of interrupts caused by hardware errors 130 * and power system events. 131 */ 132 static int __init init_ras_IRQ(void) 133 { 134 struct device_node *np; 135 136 ras_get_sensor_state_token = rtas_token("get-sensor-state"); 137 ras_check_exception_token = rtas_token("check-exception"); 138 139 /* Internal Errors */ 140 np = of_find_node_by_path("/event-sources/internal-errors"); 141 if (np != NULL) { 142 request_ras_irqs(np, ras_error_interrupt, "RAS_ERROR"); 143 of_node_put(np); 144 } 145 146 /* EPOW Events */ 147 np = of_find_node_by_path("/event-sources/epow-events"); 148 if (np != NULL) { 149 request_ras_irqs(np, ras_epow_interrupt, "RAS_EPOW"); 150 of_node_put(np); 151 } 152 153 return 0; 154 } 155 __initcall(init_ras_IRQ); 156 157 /* 158 * Handle power subsystem events (EPOW). 159 * 160 * Presently we just log the event has occurred. This should be fixed 161 * to examine the type of power failure and take appropriate action where 162 * the time horizon permits something useful to be done. 163 */ 164 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) 165 { 166 int status = 0xdeadbeef; 167 int state = 0; 168 int critical; 169 170 status = rtas_call(ras_get_sensor_state_token, 2, 2, &state, 171 EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX); 172 173 if (state > 3) 174 critical = 1; /* Time Critical */ 175 else 176 critical = 0; 177 178 spin_lock(&ras_log_buf_lock); 179 180 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 181 RAS_VECTOR_OFFSET, 182 irq_map[irq].hwirq, 183 RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS, 184 critical, __pa(&ras_log_buf), 185 rtas_get_error_log_max()); 186 187 udbg_printf("EPOW <0x%lx 0x%x 0x%x>\n", 188 *((unsigned long *)&ras_log_buf), status, state); 189 printk(KERN_WARNING "EPOW <0x%lx 0x%x 0x%x>\n", 190 *((unsigned long *)&ras_log_buf), status, state); 191 192 /* format and print the extended information */ 193 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 194 195 spin_unlock(&ras_log_buf_lock); 196 return IRQ_HANDLED; 197 } 198 199 /* 200 * Handle hardware error interrupts. 201 * 202 * RTAS check-exception is called to collect data on the exception. If 203 * the error is deemed recoverable, we log a warning and return. 204 * For nonrecoverable errors, an error is logged and we stop all processing 205 * as quickly as possible in order to prevent propagation of the failure. 206 */ 207 static irqreturn_t ras_error_interrupt(int irq, void *dev_id) 208 { 209 struct rtas_error_log *rtas_elog; 210 int status = 0xdeadbeef; 211 int fatal; 212 213 spin_lock(&ras_log_buf_lock); 214 215 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 216 RAS_VECTOR_OFFSET, 217 irq_map[irq].hwirq, 218 RTAS_INTERNAL_ERROR, 1 /*Time Critical */, 219 __pa(&ras_log_buf), 220 rtas_get_error_log_max()); 221 222 rtas_elog = (struct rtas_error_log *)ras_log_buf; 223 224 if ((status == 0) && (rtas_elog->severity >= RTAS_SEVERITY_ERROR_SYNC)) 225 fatal = 1; 226 else 227 fatal = 0; 228 229 /* format and print the extended information */ 230 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 231 232 if (fatal) { 233 udbg_printf("Fatal HW Error <0x%lx 0x%x>\n", 234 *((unsigned long *)&ras_log_buf), status); 235 printk(KERN_EMERG "Error: Fatal hardware error <0x%lx 0x%x>\n", 236 *((unsigned long *)&ras_log_buf), status); 237 238 #ifndef DEBUG_RTAS_POWER_OFF 239 /* Don't actually power off when debugging so we can test 240 * without actually failing while injecting errors. 241 * Error data will not be logged to syslog. 242 */ 243 ppc_md.power_off(); 244 #endif 245 } else { 246 udbg_printf("Recoverable HW Error <0x%lx 0x%x>\n", 247 *((unsigned long *)&ras_log_buf), status); 248 printk(KERN_WARNING 249 "Warning: Recoverable hardware error <0x%lx 0x%x>\n", 250 *((unsigned long *)&ras_log_buf), status); 251 } 252 253 spin_unlock(&ras_log_buf_lock); 254 return IRQ_HANDLED; 255 } 256 257 /* Get the error information for errors coming through the 258 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 259 * the actual r3 if possible, and a ptr to the error log entry 260 * will be returned if found. 261 * 262 * The mce_data_buf does not have any locks or protection around it, 263 * if a second machine check comes in, or a system reset is done 264 * before we have logged the error, then we will get corruption in the 265 * error log. This is preferable over holding off on calling 266 * ibm,nmi-interlock which would result in us checkstopping if a 267 * second machine check did come in. 268 */ 269 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 270 { 271 unsigned long errdata = regs->gpr[3]; 272 struct rtas_error_log *errhdr = NULL; 273 unsigned long *savep; 274 275 if ((errdata >= 0x7000 && errdata < 0x7fff0) || 276 (errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) { 277 savep = __va(errdata); 278 regs->gpr[3] = savep[0]; /* restore original r3 */ 279 memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 280 memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX); 281 errhdr = (struct rtas_error_log *)mce_data_buf; 282 } else { 283 printk("FWNMI: corrupt r3\n"); 284 } 285 return errhdr; 286 } 287 288 /* Call this when done with the data returned by FWNMI_get_errinfo. 289 * It will release the saved data area for other CPUs in the 290 * partition to receive FWNMI errors. 291 */ 292 static void fwnmi_release_errinfo(void) 293 { 294 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL); 295 if (ret != 0) 296 printk("FWNMI: nmi-interlock failed: %d\n", ret); 297 } 298 299 int pSeries_system_reset_exception(struct pt_regs *regs) 300 { 301 if (fwnmi_active) { 302 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs); 303 if (errhdr) { 304 /* XXX Should look at FWNMI information */ 305 } 306 fwnmi_release_errinfo(); 307 } 308 return 0; /* need to perform reset */ 309 } 310 311 /* 312 * See if we can recover from a machine check exception. 313 * This is only called on power4 (or above) and only via 314 * the Firmware Non-Maskable Interrupts (fwnmi) handler 315 * which provides the error analysis for us. 316 * 317 * Return 1 if corrected (or delivered a signal). 318 * Return 0 if there is nothing we can do. 319 */ 320 static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err) 321 { 322 int nonfatal = 0; 323 324 if (err->disposition == RTAS_DISP_FULLY_RECOVERED) { 325 /* Platform corrected itself */ 326 nonfatal = 1; 327 } else if ((regs->msr & MSR_RI) && 328 user_mode(regs) && 329 err->severity == RTAS_SEVERITY_ERROR_SYNC && 330 err->disposition == RTAS_DISP_NOT_RECOVERED && 331 err->target == RTAS_TARGET_MEMORY && 332 err->type == RTAS_TYPE_ECC_UNCORR && 333 !(current->pid == 0 || is_global_init(current))) { 334 /* Kill off a user process with an ECC error */ 335 printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n", 336 current->pid); 337 /* XXX something better for ECC error? */ 338 _exception(SIGBUS, regs, BUS_ADRERR, regs->nip); 339 nonfatal = 1; 340 } 341 342 log_error((char *)err, ERR_TYPE_RTAS_LOG, !nonfatal); 343 344 return nonfatal; 345 } 346 347 /* 348 * Handle a machine check. 349 * 350 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 351 * should be present. If so the handler which called us tells us if the 352 * error was recovered (never true if RI=0). 353 * 354 * On hardware prior to Power 4 these exceptions were asynchronous which 355 * means we can't tell exactly where it occurred and so we can't recover. 356 */ 357 int pSeries_machine_check_exception(struct pt_regs *regs) 358 { 359 struct rtas_error_log *errp; 360 361 if (fwnmi_active) { 362 errp = fwnmi_get_errinfo(regs); 363 fwnmi_release_errinfo(); 364 if (errp && recover_mce(regs, errp)) 365 return 1; 366 } 367 368 return 0; 369 } 370