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