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 /* #define DEBUG */ 71 72 73 static void request_ras_irqs(struct device_node *np, 74 irq_handler_t handler, 75 const char *name) 76 { 77 int i, index, count = 0; 78 struct of_irq oirq; 79 const u32 *opicprop; 80 unsigned int opicplen; 81 unsigned int virqs[16]; 82 83 /* Check for obsolete "open-pic-interrupt" property. If present, then 84 * map those interrupts using the default interrupt host and default 85 * trigger 86 */ 87 opicprop = of_get_property(np, "open-pic-interrupt", &opicplen); 88 if (opicprop) { 89 opicplen /= sizeof(u32); 90 for (i = 0; i < opicplen; i++) { 91 if (count > 15) 92 break; 93 virqs[count] = irq_create_mapping(NULL, *(opicprop++)); 94 if (virqs[count] == NO_IRQ) 95 printk(KERN_ERR "Unable to allocate interrupt " 96 "number for %s\n", np->full_name); 97 else 98 count++; 99 100 } 101 } 102 /* Else use normal interrupt tree parsing */ 103 else { 104 /* First try to do a proper OF tree parsing */ 105 for (index = 0; of_irq_map_one(np, index, &oirq) == 0; 106 index++) { 107 if (count > 15) 108 break; 109 virqs[count] = irq_create_of_mapping(oirq.controller, 110 oirq.specifier, 111 oirq.size); 112 if (virqs[count] == NO_IRQ) 113 printk(KERN_ERR "Unable to allocate interrupt " 114 "number for %s\n", np->full_name); 115 else 116 count++; 117 } 118 } 119 120 /* Now request them */ 121 for (i = 0; i < count; i++) { 122 if (request_irq(virqs[i], handler, 0, name, NULL)) { 123 printk(KERN_ERR "Unable to request interrupt %d for " 124 "%s\n", virqs[i], np->full_name); 125 return; 126 } 127 } 128 } 129 130 /* 131 * Initialize handlers for the set of interrupts caused by hardware errors 132 * and power system events. 133 */ 134 static int __init init_ras_IRQ(void) 135 { 136 struct device_node *np; 137 138 ras_get_sensor_state_token = rtas_token("get-sensor-state"); 139 ras_check_exception_token = rtas_token("check-exception"); 140 141 /* Internal Errors */ 142 np = of_find_node_by_path("/event-sources/internal-errors"); 143 if (np != NULL) { 144 request_ras_irqs(np, ras_error_interrupt, "RAS_ERROR"); 145 of_node_put(np); 146 } 147 148 /* EPOW Events */ 149 np = of_find_node_by_path("/event-sources/epow-events"); 150 if (np != NULL) { 151 request_ras_irqs(np, ras_epow_interrupt, "RAS_EPOW"); 152 of_node_put(np); 153 } 154 155 return 0; 156 } 157 __initcall(init_ras_IRQ); 158 159 /* 160 * Handle power subsystem events (EPOW). 161 * 162 * Presently we just log the event has occurred. This should be fixed 163 * to examine the type of power failure and take appropriate action where 164 * the time horizon permits something useful to be done. 165 */ 166 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) 167 { 168 int status = 0xdeadbeef; 169 int state = 0; 170 int critical; 171 172 status = rtas_call(ras_get_sensor_state_token, 2, 2, &state, 173 EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX); 174 175 if (state > 3) 176 critical = 1; /* Time Critical */ 177 else 178 critical = 0; 179 180 spin_lock(&ras_log_buf_lock); 181 182 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 183 RAS_VECTOR_OFFSET, 184 irq_map[irq].hwirq, 185 RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS, 186 critical, __pa(&ras_log_buf), 187 rtas_get_error_log_max()); 188 189 udbg_printf("EPOW <0x%lx 0x%x 0x%x>\n", 190 *((unsigned long *)&ras_log_buf), status, state); 191 printk(KERN_WARNING "EPOW <0x%lx 0x%x 0x%x>\n", 192 *((unsigned long *)&ras_log_buf), status, state); 193 194 /* format and print the extended information */ 195 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 196 197 spin_unlock(&ras_log_buf_lock); 198 return IRQ_HANDLED; 199 } 200 201 /* 202 * Handle hardware error interrupts. 203 * 204 * RTAS check-exception is called to collect data on the exception. If 205 * the error is deemed recoverable, we log a warning and return. 206 * For nonrecoverable errors, an error is logged and we stop all processing 207 * as quickly as possible in order to prevent propagation of the failure. 208 */ 209 static irqreturn_t ras_error_interrupt(int irq, void *dev_id) 210 { 211 struct rtas_error_log *rtas_elog; 212 int status = 0xdeadbeef; 213 int fatal; 214 215 spin_lock(&ras_log_buf_lock); 216 217 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 218 RAS_VECTOR_OFFSET, 219 irq_map[irq].hwirq, 220 RTAS_INTERNAL_ERROR, 1 /*Time Critical */, 221 __pa(&ras_log_buf), 222 rtas_get_error_log_max()); 223 224 rtas_elog = (struct rtas_error_log *)ras_log_buf; 225 226 if ((status == 0) && (rtas_elog->severity >= RTAS_SEVERITY_ERROR_SYNC)) 227 fatal = 1; 228 else 229 fatal = 0; 230 231 /* format and print the extended information */ 232 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 233 234 if (fatal) { 235 udbg_printf("Fatal HW Error <0x%lx 0x%x>\n", 236 *((unsigned long *)&ras_log_buf), status); 237 printk(KERN_EMERG "Error: Fatal hardware error <0x%lx 0x%x>\n", 238 *((unsigned long *)&ras_log_buf), status); 239 240 #ifndef DEBUG 241 /* Don't actually power off when debugging so we can test 242 * without actually failing while injecting errors. 243 * Error data will not be logged to syslog. 244 */ 245 ppc_md.power_off(); 246 #endif 247 } else { 248 udbg_printf("Recoverable HW Error <0x%lx 0x%x>\n", 249 *((unsigned long *)&ras_log_buf), status); 250 printk(KERN_WARNING 251 "Warning: Recoverable hardware error <0x%lx 0x%x>\n", 252 *((unsigned long *)&ras_log_buf), status); 253 } 254 255 spin_unlock(&ras_log_buf_lock); 256 return IRQ_HANDLED; 257 } 258 259 /* Get the error information for errors coming through the 260 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 261 * the actual r3 if possible, and a ptr to the error log entry 262 * will be returned if found. 263 * 264 * The mce_data_buf does not have any locks or protection around it, 265 * if a second machine check comes in, or a system reset is done 266 * before we have logged the error, then we will get corruption in the 267 * error log. This is preferable over holding off on calling 268 * ibm,nmi-interlock which would result in us checkstopping if a 269 * second machine check did come in. 270 */ 271 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 272 { 273 unsigned long errdata = regs->gpr[3]; 274 struct rtas_error_log *errhdr = NULL; 275 unsigned long *savep; 276 277 if ((errdata >= 0x7000 && errdata < 0x7fff0) || 278 (errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) { 279 savep = __va(errdata); 280 regs->gpr[3] = savep[0]; /* restore original r3 */ 281 memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 282 memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX); 283 errhdr = (struct rtas_error_log *)mce_data_buf; 284 } else { 285 printk("FWNMI: corrupt r3\n"); 286 } 287 return errhdr; 288 } 289 290 /* Call this when done with the data returned by FWNMI_get_errinfo. 291 * It will release the saved data area for other CPUs in the 292 * partition to receive FWNMI errors. 293 */ 294 static void fwnmi_release_errinfo(void) 295 { 296 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL); 297 if (ret != 0) 298 printk("FWNMI: nmi-interlock failed: %d\n", ret); 299 } 300 301 int pSeries_system_reset_exception(struct pt_regs *regs) 302 { 303 if (fwnmi_active) { 304 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs); 305 if (errhdr) { 306 /* XXX Should look at FWNMI information */ 307 } 308 fwnmi_release_errinfo(); 309 } 310 return 0; /* need to perform reset */ 311 } 312 313 /* 314 * See if we can recover from a machine check exception. 315 * This is only called on power4 (or above) and only via 316 * the Firmware Non-Maskable Interrupts (fwnmi) handler 317 * which provides the error analysis for us. 318 * 319 * Return 1 if corrected (or delivered a signal). 320 * Return 0 if there is nothing we can do. 321 */ 322 static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err) 323 { 324 int nonfatal = 0; 325 326 if (err->disposition == RTAS_DISP_FULLY_RECOVERED) { 327 /* Platform corrected itself */ 328 nonfatal = 1; 329 } else if ((regs->msr & MSR_RI) && 330 user_mode(regs) && 331 err->severity == RTAS_SEVERITY_ERROR_SYNC && 332 err->disposition == RTAS_DISP_NOT_RECOVERED && 333 err->target == RTAS_TARGET_MEMORY && 334 err->type == RTAS_TYPE_ECC_UNCORR && 335 !(current->pid == 0 || is_init(current))) { 336 /* Kill off a user process with an ECC error */ 337 printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n", 338 current->pid); 339 /* XXX something better for ECC error? */ 340 _exception(SIGBUS, regs, BUS_ADRERR, regs->nip); 341 nonfatal = 1; 342 } 343 344 log_error((char *)err, ERR_TYPE_RTAS_LOG, !nonfatal); 345 346 return nonfatal; 347 } 348 349 /* 350 * Handle a machine check. 351 * 352 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 353 * should be present. If so the handler which called us tells us if the 354 * error was recovered (never true if RI=0). 355 * 356 * On hardware prior to Power 4 these exceptions were asynchronous which 357 * means we can't tell exactly where it occurred and so we can't recover. 358 */ 359 int pSeries_machine_check_exception(struct pt_regs *regs) 360 { 361 struct rtas_error_log *errp; 362 363 if (fwnmi_active) { 364 errp = fwnmi_get_errinfo(regs); 365 fwnmi_release_errinfo(); 366 if (errp && recover_mce(regs, errp)) 367 return 1; 368 } 369 370 return 0; 371 } 372