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