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/pci.h> 35 #include <linux/delay.h> 36 #include <linux/irq.h> 37 #include <linux/random.h> 38 #include <linux/sysrq.h> 39 #include <linux/bitops.h> 40 41 #include <asm/uaccess.h> 42 #include <asm/system.h> 43 #include <asm/io.h> 44 #include <asm/pgtable.h> 45 #include <asm/irq.h> 46 #include <asm/cache.h> 47 #include <asm/prom.h> 48 #include <asm/ptrace.h> 49 #include <asm/machdep.h> 50 #include <asm/rtas.h> 51 #include <asm/udbg.h> 52 #include <asm/firmware.h> 53 54 #include "ras.h" 55 56 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX]; 57 static DEFINE_SPINLOCK(ras_log_buf_lock); 58 59 char mce_data_buf[RTAS_ERROR_LOG_MAX]; 60 61 static int ras_get_sensor_state_token; 62 static int ras_check_exception_token; 63 64 #define EPOW_SENSOR_TOKEN 9 65 #define EPOW_SENSOR_INDEX 0 66 #define RAS_VECTOR_OFFSET 0x500 67 68 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id, 69 struct pt_regs * regs); 70 static irqreturn_t ras_error_interrupt(int irq, void *dev_id, 71 struct pt_regs * regs); 72 73 /* #define DEBUG */ 74 75 76 static void request_ras_irqs(struct device_node *np, 77 irqreturn_t (*handler)(int, void *, struct pt_regs *), 78 const char *name) 79 { 80 int i, index, count = 0; 81 struct of_irq oirq; 82 u32 *opicprop; 83 unsigned int opicplen; 84 unsigned int virqs[16]; 85 86 /* Check for obsolete "open-pic-interrupt" property. If present, then 87 * map those interrupts using the default interrupt host and default 88 * trigger 89 */ 90 opicprop = (u32 *)get_property(np, "open-pic-interrupt", &opicplen); 91 if (opicprop) { 92 opicplen /= sizeof(u32); 93 for (i = 0; i < opicplen; i++) { 94 if (count > 15) 95 break; 96 virqs[count] = irq_create_mapping(NULL, *(opicprop++), 97 IRQ_TYPE_NONE); 98 if (virqs[count] == NO_IRQ) 99 printk(KERN_ERR "Unable to allocate interrupt " 100 "number for %s\n", np->full_name); 101 else 102 count++; 103 104 } 105 } 106 /* Else use normal interrupt tree parsing */ 107 else { 108 /* First try to do a proper OF tree parsing */ 109 for (index = 0; of_irq_map_one(np, index, &oirq) == 0; 110 index++) { 111 if (count > 15) 112 break; 113 virqs[count] = irq_create_of_mapping(oirq.controller, 114 oirq.specifier, 115 oirq.size); 116 if (virqs[count] == NO_IRQ) 117 printk(KERN_ERR "Unable to allocate interrupt " 118 "number for %s\n", np->full_name); 119 else 120 count++; 121 } 122 } 123 124 /* Now request them */ 125 for (i = 0; i < count; i++) { 126 if (request_irq(virqs[i], handler, 0, name, NULL)) { 127 printk(KERN_ERR "Unable to request interrupt %d for " 128 "%s\n", virqs[i], np->full_name); 129 return; 130 } 131 } 132 } 133 134 /* 135 * Initialize handlers for the set of interrupts caused by hardware errors 136 * and power system events. 137 */ 138 static int __init init_ras_IRQ(void) 139 { 140 struct device_node *np; 141 142 ras_get_sensor_state_token = rtas_token("get-sensor-state"); 143 ras_check_exception_token = rtas_token("check-exception"); 144 145 /* Internal Errors */ 146 np = of_find_node_by_path("/event-sources/internal-errors"); 147 if (np != NULL) { 148 request_ras_irqs(np, ras_error_interrupt, "RAS_ERROR"); 149 of_node_put(np); 150 } 151 152 /* EPOW Events */ 153 np = of_find_node_by_path("/event-sources/epow-events"); 154 if (np != NULL) { 155 request_ras_irqs(np, ras_epow_interrupt, "RAS_EPOW"); 156 of_node_put(np); 157 } 158 159 return 0; 160 } 161 __initcall(init_ras_IRQ); 162 163 /* 164 * Handle power subsystem events (EPOW). 165 * 166 * Presently we just log the event has occurred. This should be fixed 167 * to examine the type of power failure and take appropriate action where 168 * the time horizon permits something useful to be done. 169 */ 170 static irqreturn_t 171 ras_epow_interrupt(int irq, void *dev_id, struct pt_regs * regs) 172 { 173 int status = 0xdeadbeef; 174 int state = 0; 175 int critical; 176 177 status = rtas_call(ras_get_sensor_state_token, 2, 2, &state, 178 EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX); 179 180 if (state > 3) 181 critical = 1; /* Time Critical */ 182 else 183 critical = 0; 184 185 spin_lock(&ras_log_buf_lock); 186 187 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 188 RAS_VECTOR_OFFSET, 189 irq_map[irq].hwirq, 190 RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS, 191 critical, __pa(&ras_log_buf), 192 rtas_get_error_log_max()); 193 194 udbg_printf("EPOW <0x%lx 0x%x 0x%x>\n", 195 *((unsigned long *)&ras_log_buf), status, state); 196 printk(KERN_WARNING "EPOW <0x%lx 0x%x 0x%x>\n", 197 *((unsigned long *)&ras_log_buf), status, state); 198 199 /* format and print the extended information */ 200 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 201 202 spin_unlock(&ras_log_buf_lock); 203 return IRQ_HANDLED; 204 } 205 206 /* 207 * Handle hardware error interrupts. 208 * 209 * RTAS check-exception is called to collect data on the exception. If 210 * the error is deemed recoverable, we log a warning and return. 211 * For nonrecoverable errors, an error is logged and we stop all processing 212 * as quickly as possible in order to prevent propagation of the failure. 213 */ 214 static irqreturn_t 215 ras_error_interrupt(int irq, void *dev_id, struct pt_regs * regs) 216 { 217 struct rtas_error_log *rtas_elog; 218 int status = 0xdeadbeef; 219 int fatal; 220 221 spin_lock(&ras_log_buf_lock); 222 223 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 224 RAS_VECTOR_OFFSET, 225 irq_map[irq].hwirq, 226 RTAS_INTERNAL_ERROR, 1 /*Time Critical */, 227 __pa(&ras_log_buf), 228 rtas_get_error_log_max()); 229 230 rtas_elog = (struct rtas_error_log *)ras_log_buf; 231 232 if ((status == 0) && (rtas_elog->severity >= RTAS_SEVERITY_ERROR_SYNC)) 233 fatal = 1; 234 else 235 fatal = 0; 236 237 /* format and print the extended information */ 238 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 239 240 if (fatal) { 241 udbg_printf("Fatal HW Error <0x%lx 0x%x>\n", 242 *((unsigned long *)&ras_log_buf), status); 243 printk(KERN_EMERG "Error: Fatal hardware error <0x%lx 0x%x>\n", 244 *((unsigned long *)&ras_log_buf), status); 245 246 #ifndef DEBUG 247 /* Don't actually power off when debugging so we can test 248 * without actually failing while injecting errors. 249 * Error data will not be logged to syslog. 250 */ 251 ppc_md.power_off(); 252 #endif 253 } else { 254 udbg_printf("Recoverable HW Error <0x%lx 0x%x>\n", 255 *((unsigned long *)&ras_log_buf), status); 256 printk(KERN_WARNING 257 "Warning: Recoverable hardware error <0x%lx 0x%x>\n", 258 *((unsigned long *)&ras_log_buf), status); 259 } 260 261 spin_unlock(&ras_log_buf_lock); 262 return IRQ_HANDLED; 263 } 264 265 /* Get the error information for errors coming through the 266 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 267 * the actual r3 if possible, and a ptr to the error log entry 268 * will be returned if found. 269 * 270 * The mce_data_buf does not have any locks or protection around it, 271 * if a second machine check comes in, or a system reset is done 272 * before we have logged the error, then we will get corruption in the 273 * error log. This is preferable over holding off on calling 274 * ibm,nmi-interlock which would result in us checkstopping if a 275 * second machine check did come in. 276 */ 277 static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 278 { 279 unsigned long errdata = regs->gpr[3]; 280 struct rtas_error_log *errhdr = NULL; 281 unsigned long *savep; 282 283 if ((errdata >= 0x7000 && errdata < 0x7fff0) || 284 (errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) { 285 savep = __va(errdata); 286 regs->gpr[3] = savep[0]; /* restore original r3 */ 287 memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 288 memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX); 289 errhdr = (struct rtas_error_log *)mce_data_buf; 290 } else { 291 printk("FWNMI: corrupt r3\n"); 292 } 293 return errhdr; 294 } 295 296 /* Call this when done with the data returned by FWNMI_get_errinfo. 297 * It will release the saved data area for other CPUs in the 298 * partition to receive FWNMI errors. 299 */ 300 static void fwnmi_release_errinfo(void) 301 { 302 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL); 303 if (ret != 0) 304 printk("FWNMI: nmi-interlock failed: %d\n", ret); 305 } 306 307 int pSeries_system_reset_exception(struct pt_regs *regs) 308 { 309 if (fwnmi_active) { 310 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs); 311 if (errhdr) { 312 /* XXX Should look at FWNMI information */ 313 } 314 fwnmi_release_errinfo(); 315 } 316 return 0; /* need to perform reset */ 317 } 318 319 /* 320 * See if we can recover from a machine check exception. 321 * This is only called on power4 (or above) and only via 322 * the Firmware Non-Maskable Interrupts (fwnmi) handler 323 * which provides the error analysis for us. 324 * 325 * Return 1 if corrected (or delivered a signal). 326 * Return 0 if there is nothing we can do. 327 */ 328 static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err) 329 { 330 int nonfatal = 0; 331 332 if (err->disposition == RTAS_DISP_FULLY_RECOVERED) { 333 /* Platform corrected itself */ 334 nonfatal = 1; 335 } else if ((regs->msr & MSR_RI) && 336 user_mode(regs) && 337 err->severity == RTAS_SEVERITY_ERROR_SYNC && 338 err->disposition == RTAS_DISP_NOT_RECOVERED && 339 err->target == RTAS_TARGET_MEMORY && 340 err->type == RTAS_TYPE_ECC_UNCORR && 341 !(current->pid == 0 || current->pid == 1)) { 342 /* Kill off a user process with an ECC error */ 343 printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n", 344 current->pid); 345 /* XXX something better for ECC error? */ 346 _exception(SIGBUS, regs, BUS_ADRERR, regs->nip); 347 nonfatal = 1; 348 } 349 350 log_error((char *)err, ERR_TYPE_RTAS_LOG, !nonfatal); 351 352 return nonfatal; 353 } 354 355 /* 356 * Handle a machine check. 357 * 358 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 359 * should be present. If so the handler which called us tells us if the 360 * error was recovered (never true if RI=0). 361 * 362 * On hardware prior to Power 4 these exceptions were asynchronous which 363 * means we can't tell exactly where it occurred and so we can't recover. 364 */ 365 int pSeries_machine_check_exception(struct pt_regs *regs) 366 { 367 struct rtas_error_log *errp; 368 369 if (fwnmi_active) { 370 errp = fwnmi_get_errinfo(regs); 371 fwnmi_release_errinfo(); 372 if (errp && recover_mce(regs, errp)) 373 return 1; 374 } 375 376 return 0; 377 } 378