release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/platforms/pseries/ras.c

   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
  54 static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
  55 static DEFINE_SPINLOCK(ras_log_buf_lock);
  56
  57 static char mce_data_buf[RTAS_ERROR_LOG_MAX];
  58
  59 static int ras_get_sensor_state_token;
  60 static int ras_check_exception_token;
  61
  62 #define EPOW_SENSOR_TOKEN       9
  63 #define EPOW_SENSOR_INDEX       0
  64
  65 static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
  66 static 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  */
  73 static 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  */
 106 static 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  */
 149 static 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  */
 211 static 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  */
 234 static 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
 241 int 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  */
 261 static 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  */
 297 int 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 }