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/delay.h> 34#include <linux/irq.h> 35#include <linux/random.h> 36#include <linux/sysrq.h> 37#include <linux/bitops.h> 38 39#include <asm/uaccess.h> 40#include <asm/system.h> 41#include <asm/io.h> 42#include <asm/pgtable.h> 43#include <asm/irq.h> 44#include <asm/cache.h> 45#include <asm/prom.h> 46#include <asm/ptrace.h> 47#include <asm/machdep.h> 48#include <asm/rtas.h> 49#include <asm/udbg.h> 50#include <asm/firmware.h> 51 52#include "pseries.h" 53 54static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX]; 55static DEFINE_SPINLOCK(ras_log_buf_lock); 56 57static char mce_data_buf[RTAS_ERROR_LOG_MAX]; 58 59static int ras_get_sensor_state_token; 60static int ras_check_exception_token; 61 62#define EPOW_SENSOR_TOKEN 9 63#define EPOW_SENSOR_INDEX 0 64 65static irqreturn_t ras_epow_interrupt(int irq, void *dev_id); 66static irqreturn_t ras_error_interrupt(int irq, void *dev_id); 67 68 69/* 70 * Initialize handlers for the set of interrupts caused by hardware errors 71 * and power system events. 72 */ 73static int __init init_ras_IRQ(void) 74{ 75 struct device_node *np; 76 77 ras_get_sensor_state_token = rtas_token("get-sensor-state"); 78 ras_check_exception_token = rtas_token("check-exception"); 79 80 /* Internal Errors */ 81 np = of_find_node_by_path("/event-sources/internal-errors"); 82 if (np != NULL) { 83 request_event_sources_irqs(np, ras_error_interrupt, 84 "RAS_ERROR"); 85 of_node_put(np); 86 } 87 88 /* EPOW Events */ 89 np = of_find_node_by_path("/event-sources/epow-events"); 90 if (np != NULL) { 91 request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW"); 92 of_node_put(np); 93 } 94 95 return 0; 96} 97__initcall(init_ras_IRQ); 98 99/* 100 * Handle power subsystem events (EPOW). 101 * 102 * Presently we just log the event has occurred. This should be fixed 103 * to examine the type of power failure and take appropriate action where 104 * the time horizon permits something useful to be done. 105 */ 106static irqreturn_t ras_epow_interrupt(int irq, void *dev_id) 107{ 108 int status = 0xdeadbeef; 109 int state = 0; 110 int critical; 111 112 status = rtas_call(ras_get_sensor_state_token, 2, 2, &state, 113 EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX); 114 115 if (state > 3) 116 critical = 1; /* Time Critical */ 117 else 118 critical = 0; 119 120 spin_lock(&ras_log_buf_lock); 121 122 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 123 RTAS_VECTOR_EXTERNAL_INTERRUPT, 124 irq_map[irq].hwirq, 125 RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS, 126 critical, __pa(&ras_log_buf), 127 rtas_get_error_log_max()); 128 129 udbg_printf("EPOW <0x%lx 0x%x 0x%x>\n", 130 *((unsigned long *)&ras_log_buf), status, state); 131 printk(KERN_WARNING "EPOW <0x%lx 0x%x 0x%x>\n", 132 *((unsigned long *)&ras_log_buf), status, state); 133 134 /* format and print the extended information */ 135 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0); 136 137 spin_unlock(&ras_log_buf_lock); 138 return IRQ_HANDLED; 139} 140 141/* 142 * Handle hardware error interrupts. 143 * 144 * RTAS check-exception is called to collect data on the exception. If 145 * the error is deemed recoverable, we log a warning and return. 146 * For nonrecoverable errors, an error is logged and we stop all processing 147 * as quickly as possible in order to prevent propagation of the failure. 148 */ 149static irqreturn_t ras_error_interrupt(int irq, void *dev_id) 150{ 151 struct rtas_error_log *rtas_elog; 152 int status = 0xdeadbeef; 153 int fatal; 154 155 spin_lock(&ras_log_buf_lock); 156 157 status = rtas_call(ras_check_exception_token, 6, 1, NULL, 158 RTAS_VECTOR_EXTERNAL_INTERRUPT, 159 irq_map[irq].hwirq, 160 RTAS_INTERNAL_ERROR, 1 /*Time Critical */, 161 __pa(&ras_log_buf), 162 rtas_get_error_log_max()); 163 164 rtas_elog = (struct rtas_error_log *)ras_log_buf; 165 166 if ((status == 0) && (rtas_elog->severity >= RTAS_SEVERITY_ERROR_SYNC)) 167 fatal = 1; 168 else 169 fatal = 0; 170 171 /* format and print the extended information */ 172 log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal); 173 174 if (fatal) { 175 udbg_printf("Fatal HW Error <0x%lx 0x%x>\n", 176 *((unsigned long *)&ras_log_buf), status); 177 printk(KERN_EMERG "Error: Fatal hardware error <0x%lx 0x%x>\n", 178 *((unsigned long *)&ras_log_buf), status); 179 180#ifndef DEBUG_RTAS_POWER_OFF 181 /* Don't actually power off when debugging so we can test 182 * without actually failing while injecting errors. 183 * Error data will not be logged to syslog. 184 */ 185 ppc_md.power_off(); 186#endif 187 } else { 188 udbg_printf("Recoverable HW Error <0x%lx 0x%x>\n", 189 *((unsigned long *)&ras_log_buf), status); 190 printk(KERN_WARNING 191 "Warning: Recoverable hardware error <0x%lx 0x%x>\n", 192 *((unsigned long *)&ras_log_buf), status); 193 } 194 195 spin_unlock(&ras_log_buf_lock); 196 return IRQ_HANDLED; 197} 198 199/* Get the error information for errors coming through the 200 * FWNMI vectors. The pt_regs' r3 will be updated to reflect 201 * the actual r3 if possible, and a ptr to the error log entry 202 * will be returned if found. 203 * 204 * The mce_data_buf does not have any locks or protection around it, 205 * if a second machine check comes in, or a system reset is done 206 * before we have logged the error, then we will get corruption in the 207 * error log. This is preferable over holding off on calling 208 * ibm,nmi-interlock which would result in us checkstopping if a 209 * second machine check did come in. 210 */ 211static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) 212{ 213 unsigned long errdata = regs->gpr[3]; 214 struct rtas_error_log *errhdr = NULL; 215 unsigned long *savep; 216 217 if ((errdata >= 0x7000 && errdata < 0x7fff0) || 218 (errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) { 219 savep = __va(errdata); 220 regs->gpr[3] = savep[0]; /* restore original r3 */ 221 memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX); 222 memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX); 223 errhdr = (struct rtas_error_log *)mce_data_buf; 224 } else { 225 printk("FWNMI: corrupt r3\n"); 226 } 227 return errhdr; 228} 229 230/* Call this when done with the data returned by FWNMI_get_errinfo. 231 * It will release the saved data area for other CPUs in the 232 * partition to receive FWNMI errors. 233 */ 234static void fwnmi_release_errinfo(void) 235{ 236 int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL); 237 if (ret != 0) 238 printk("FWNMI: nmi-interlock failed: %d\n", ret); 239} 240 241int pSeries_system_reset_exception(struct pt_regs *regs) 242{ 243 if (fwnmi_active) { 244 struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs); 245 if (errhdr) { 246 } 247 fwnmi_release_errinfo(); 248 } 249 return 0; /* need to perform reset */ 250} 251 252/* 253 * See if we can recover from a machine check exception. 254 * This is only called on power4 (or above) and only via 255 * the Firmware Non-Maskable Interrupts (fwnmi) handler 256 * which provides the error analysis for us. 257 * 258 * Return 1 if corrected (or delivered a signal). 259 * Return 0 if there is nothing we can do. 260 */ 261static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err) 262{ 263 int nonfatal = 0; 264 265 if (err->disposition == RTAS_DISP_FULLY_RECOVERED) { 266 /* Platform corrected itself */ 267 nonfatal = 1; 268 } else if ((regs->msr & MSR_RI) && 269 user_mode(regs) && 270 err->severity == RTAS_SEVERITY_ERROR_SYNC && 271 err->disposition == RTAS_DISP_NOT_RECOVERED && 272 err->target == RTAS_TARGET_MEMORY && 273 err->type == RTAS_TYPE_ECC_UNCORR && 274 !(current->pid == 0 || is_global_init(current))) { 275 /* Kill off a user process with an ECC error */ 276 printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n", 277 current->pid); 278 _exception(SIGBUS, regs, BUS_ADRERR, regs->nip); 279 nonfatal = 1; 280 } 281 282 log_error((char *)err, ERR_TYPE_RTAS_LOG, !nonfatal); 283 284 return nonfatal; 285} 286 287/* 288 * Handle a machine check. 289 * 290 * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi) 291 * should be present. If so the handler which called us tells us if the 292 * error was recovered (never true if RI=0). 293 * 294 * On hardware prior to Power 4 these exceptions were asynchronous which 295 * means we can't tell exactly where it occurred and so we can't recover. 296 */ 297int pSeries_machine_check_exception(struct pt_regs *regs) 298{ 299 struct rtas_error_log *errp; 300 301 if (fwnmi_active) { 302 errp = fwnmi_get_errinfo(regs); 303 fwnmi_release_errinfo(); 304 if (errp && recover_mce(regs, errp)) 305 return 1; 306 } 307 308 return 0; 309} 310