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