arch/powerpc/platforms/powernv/opal.c

   1 /*
   2  * PowerNV OPAL high level interfaces
   3  *
   4  * Copyright 2011 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #undef DEBUG
  13
  14 #include <linux/types.h>
  15 #include <linux/of.h>
  16 #include <linux/of_fdt.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/notifier.h>
  20 #include <linux/slab.h>
  21 #include <linux/sched.h>
  22 #include <linux/kobject.h>
  23 #include <linux/delay.h>
  24 #include <asm/opal.h>
  25 #include <asm/firmware.h>
  26 #include <asm/mce.h>
  27
  28 #include "powernv.h"
  29
  30 /* /sys/firmware/opal */
  31 struct kobject *opal_kobj;
  32
  33 struct opal {
  34         u64 base;
  35         u64 entry;
  36 } opal;
  37
  38 static struct device_node *opal_node;
  39 static DEFINE_SPINLOCK(opal_write_lock);
  40 extern u64 opal_mc_secondary_handler[];
  41 static unsigned int *opal_irqs;
  42 static unsigned int opal_irq_count;
  43 static ATOMIC_NOTIFIER_HEAD(opal_notifier_head);
  44 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
  45 static DEFINE_SPINLOCK(opal_notifier_lock);
  46 static uint64_t last_notified_mask = 0x0ul;
  47 static atomic_t opal_notifier_hold = ATOMIC_INIT(0);
  48
  49 int __init early_init_dt_scan_opal(unsigned long node,
  50                                    const char *uname, int depth, void *data)
  51 {
  52         const void *basep, *entryp;
  53         int basesz, entrysz;
  54
  55         if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
  56                 return 0;
  57
  58         basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
  59         entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
  60
  61         if (!basep || !entryp)
  62                 return 1;
  63
  64         opal.base = of_read_number(basep, basesz/4);
  65         opal.entry = of_read_number(entryp, entrysz/4);
  66
  67         pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%d)\n",
  68                  opal.base, basep, basesz);
  69         pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%d)\n",
  70                  opal.entry, entryp, entrysz);
  71
  72         powerpc_firmware_features |= FW_FEATURE_OPAL;
  73         if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
  74                 powerpc_firmware_features |= FW_FEATURE_OPALv2;
  75                 powerpc_firmware_features |= FW_FEATURE_OPALv3;
  76                 printk("OPAL V3 detected !\n");
  77         } else if (of_flat_dt_is_compatible(node, "ibm,opal-v2")) {
  78                 powerpc_firmware_features |= FW_FEATURE_OPALv2;
  79                 printk("OPAL V2 detected !\n");
  80         } else {
  81                 printk("OPAL V1 detected !\n");
  82         }
  83
  84         return 1;
  85 }
  86
  87 static int __init opal_register_exception_handlers(void)
  88 {
  89 #ifdef __BIG_ENDIAN__
  90         u64 glue;
  91
  92         if (!(powerpc_firmware_features & FW_FEATURE_OPAL))
  93                 return -ENODEV;
  94
  95         /* Hookup some exception handlers except machine check. We use the
  96          * fwnmi area at 0x7000 to provide the glue space to OPAL
  97          */
  98         glue = 0x7000;
  99         opal_register_exception_handler(OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
 100                                         0, glue);
 101         glue += 128;
 102         opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
 103 #endif
 104
 105         return 0;
 106 }
 107
 108 early_initcall(opal_register_exception_handlers);
 109
 110 int opal_notifier_register(struct notifier_block *nb)
 111 {
 112         if (!nb) {
 113                 pr_warning("%s: Invalid argument (%p)\n",
 114                            __func__, nb);
 115                 return -EINVAL;
 116         }
 117
 118         atomic_notifier_chain_register(&opal_notifier_head, nb);
 119         return 0;
 120 }
 121
 122 static void opal_do_notifier(uint64_t events)
 123 {
 124         unsigned long flags;
 125         uint64_t changed_mask;
 126
 127         if (atomic_read(&opal_notifier_hold))
 128                 return;
 129
 130         spin_lock_irqsave(&opal_notifier_lock, flags);
 131         changed_mask = last_notified_mask ^ events;
 132         last_notified_mask = events;
 133         spin_unlock_irqrestore(&opal_notifier_lock, flags);
 134
 135         /*
 136          * We feed with the event bits and changed bits for
 137          * enough information to the callback.
 138          */
 139         atomic_notifier_call_chain(&opal_notifier_head,
 140                                    events, (void *)changed_mask);
 141 }
 142
 143 void opal_notifier_update_evt(uint64_t evt_mask,
 144                               uint64_t evt_val)
 145 {
 146         unsigned long flags;
 147
 148         spin_lock_irqsave(&opal_notifier_lock, flags);
 149         last_notified_mask &= ~evt_mask;
 150         last_notified_mask |= evt_val;
 151         spin_unlock_irqrestore(&opal_notifier_lock, flags);
 152 }
 153
 154 void opal_notifier_enable(void)
 155 {
 156         int64_t rc;
 157         uint64_t evt = 0;
 158
 159         atomic_set(&opal_notifier_hold, 0);
 160
 161         /* Process pending events */
 162         rc = opal_poll_events(&evt);
 163         if (rc == OPAL_SUCCESS && evt)
 164                 opal_do_notifier(evt);
 165 }
 166
 167 void opal_notifier_disable(void)
 168 {
 169         atomic_set(&opal_notifier_hold, 1);
 170 }
 171
 172 /*
 173  * Opal message notifier based on message type. Allow subscribers to get
 174  * notified for specific messgae type.
 175  */
 176 int opal_message_notifier_register(enum OpalMessageType msg_type,
 177                                         struct notifier_block *nb)
 178 {
 179         if (!nb) {
 180                 pr_warning("%s: Invalid argument (%p)\n",
 181                            __func__, nb);
 182                 return -EINVAL;
 183         }
 184         if (msg_type > OPAL_MSG_TYPE_MAX) {
 185                 pr_warning("%s: Invalid message type argument (%d)\n",
 186                            __func__, msg_type);
 187                 return -EINVAL;
 188         }
 189         return atomic_notifier_chain_register(
 190                                 &opal_msg_notifier_head[msg_type], nb);
 191 }
 192
 193 static void opal_message_do_notify(uint32_t msg_type, void *msg)
 194 {
 195         /* notify subscribers */
 196         atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
 197                                         msg_type, msg);
 198 }
 199
 200 static void opal_handle_message(void)
 201 {
 202         s64 ret;
 203         /*
 204          * TODO: pre-allocate a message buffer depending on opal-msg-size
 205          * value in /proc/device-tree.
 206          */
 207         static struct opal_msg msg;
 208
 209         ret = opal_get_msg(__pa(&msg), sizeof(msg));
 210         /* No opal message pending. */
 211         if (ret == OPAL_RESOURCE)
 212                 return;
 213
 214         /* check for errors. */
 215         if (ret) {
 216                 pr_warning("%s: Failed to retrive opal message, err=%lld\n",
 217                                 __func__, ret);
 218                 return;
 219         }
 220
 221         /* Sanity check */
 222         if (msg.msg_type > OPAL_MSG_TYPE_MAX) {
 223                 pr_warning("%s: Unknown message type: %u\n",
 224                                 __func__, msg.msg_type);
 225                 return;
 226         }
 227         opal_message_do_notify(msg.msg_type, (void *)&msg);
 228 }
 229
 230 static int opal_message_notify(struct notifier_block *nb,
 231                           unsigned long events, void *change)
 232 {
 233         if (events & OPAL_EVENT_MSG_PENDING)
 234                 opal_handle_message();
 235         return 0;
 236 }
 237
 238 static struct notifier_block opal_message_nb = {
 239         .notifier_call  = opal_message_notify,
 240         .next           = NULL,
 241         .priority       = 0,
 242 };
 243
 244 static int __init opal_message_init(void)
 245 {
 246         int ret, i;
 247
 248         for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
 249                 ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);
 250
 251         ret = opal_notifier_register(&opal_message_nb);
 252         if (ret) {
 253                 pr_err("%s: Can't register OPAL event notifier (%d)\n",
 254                        __func__, ret);
 255                 return ret;
 256         }
 257         return 0;
 258 }
 259 early_initcall(opal_message_init);
 260
 261 int opal_get_chars(uint32_t vtermno, char *buf, int count)
 262 {
 263         s64 rc;
 264         __be64 evt, len;
 265
 266         if (!opal.entry)
 267                 return -ENODEV;
 268         opal_poll_events(&evt);
 269         if ((be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_INPUT) == 0)
 270                 return 0;
 271         len = cpu_to_be64(count);
 272         rc = opal_console_read(vtermno, &len, buf);
 273         if (rc == OPAL_SUCCESS)
 274                 return be64_to_cpu(len);
 275         return 0;
 276 }
 277
 278 int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
 279 {
 280         int written = 0;
 281         __be64 olen;
 282         s64 len, rc;
 283         unsigned long flags;
 284         __be64 evt;
 285
 286         if (!opal.entry)
 287                 return -ENODEV;
 288
 289         /* We want put_chars to be atomic to avoid mangling of hvsi
 290          * packets. To do that, we first test for room and return
 291          * -EAGAIN if there isn't enough.
 292          *
 293          * Unfortunately, opal_console_write_buffer_space() doesn't
 294          * appear to work on opal v1, so we just assume there is
 295          * enough room and be done with it
 296          */
 297         spin_lock_irqsave(&opal_write_lock, flags);
 298         if (firmware_has_feature(FW_FEATURE_OPALv2)) {
 299                 rc = opal_console_write_buffer_space(vtermno, &olen);
 300                 len = be64_to_cpu(olen);
 301                 if (rc || len < total_len) {
 302                         spin_unlock_irqrestore(&opal_write_lock, flags);
 303                         /* Closed -> drop characters */
 304                         if (rc)
 305                                 return total_len;
 306                         opal_poll_events(NULL);
 307                         return -EAGAIN;
 308                 }
 309         }
 310
 311         /* We still try to handle partial completions, though they
 312          * should no longer happen.
 313          */
 314         rc = OPAL_BUSY;
 315         while(total_len > 0 && (rc == OPAL_BUSY ||
 316                                 rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
 317                 olen = cpu_to_be64(total_len);
 318                 rc = opal_console_write(vtermno, &olen, data);
 319                 len = be64_to_cpu(olen);
 320
 321                 /* Closed or other error drop */
 322                 if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
 323                     rc != OPAL_BUSY_EVENT) {
 324                         written = total_len;
 325                         break;
 326                 }
 327                 if (rc == OPAL_SUCCESS) {
 328                         total_len -= len;
 329                         data += len;
 330                         written += len;
 331                 }
 332                 /* This is a bit nasty but we need that for the console to
 333                  * flush when there aren't any interrupts. We will clean
 334                  * things a bit later to limit that to synchronous path
 335                  * such as the kernel console and xmon/udbg
 336                  */
 337                 do
 338                         opal_poll_events(&evt);
 339                 while(rc == OPAL_SUCCESS &&
 340                         (be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT));
 341         }
 342         spin_unlock_irqrestore(&opal_write_lock, flags);
 343         return written;
 344 }
 345
 346 static int opal_recover_mce(struct pt_regs *regs,
 347                                         struct machine_check_event *evt)
 348 {
 349         int recovered = 0;
 350         uint64_t ea = get_mce_fault_addr(evt);
 351
 352         if (!(regs->msr & MSR_RI)) {
 353                 /* If MSR_RI isn't set, we cannot recover */
 354                 recovered = 0;
 355         } else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
 356                 /* Platform corrected itself */
 357                 recovered = 1;
 358         } else if (ea && !is_kernel_addr(ea)) {
 359                 /*
 360                  * Faulting address is not in kernel text. We should be fine.
 361                  * We need to find which process uses this address.
 362                  * For now, kill the task if we have received exception when
 363                  * in userspace.
 364                  *
 365                  * TODO: Queue up this address for hwpoisioning later.
 366                  */
 367                 if (user_mode(regs) && !is_global_init(current)) {
 368                         _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 369                         recovered = 1;
 370                 } else
 371                         recovered = 0;
 372         } else if (user_mode(regs) && !is_global_init(current) &&
 373                 evt->severity == MCE_SEV_ERROR_SYNC) {
 374                 /*
 375                  * If we have received a synchronous error when in userspace
 376                  * kill the task.
 377                  */
 378                 _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
 379                 recovered = 1;
 380         }
 381         return recovered;
 382 }
 383
 384 int opal_machine_check(struct pt_regs *regs)
 385 {
 386         struct machine_check_event evt;
 387
 388         if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
 389                 return 0;
 390
 391         /* Print things out */
 392         if (evt.version != MCE_V1) {
 393                 pr_err("Machine Check Exception, Unknown event version %d !\n",
 394                        evt.version);
 395                 return 0;
 396         }
 397         machine_check_print_event_info(&evt);
 398
 399         if (opal_recover_mce(regs, &evt))
 400                 return 1;
 401         return 0;
 402 }
 403
 404 static irqreturn_t opal_interrupt(int irq, void *data)
 405 {
 406         __be64 events;
 407
 408         opal_handle_interrupt(virq_to_hw(irq), &events);
 409
 410         opal_do_notifier(events);
 411
 412         return IRQ_HANDLED;
 413 }
 414
 415 static int opal_sysfs_init(void)
 416 {
 417         opal_kobj = kobject_create_and_add("opal", firmware_kobj);
 418         if (!opal_kobj) {
 419                 pr_warn("kobject_create_and_add opal failed\n");
 420                 return -ENOMEM;
 421         }
 422
 423         return 0;
 424 }
 425
 426 static int __init opal_init(void)
 427 {
 428         struct device_node *np, *consoles;
 429         const __be32 *irqs;
 430         int rc, i, irqlen;
 431
 432         opal_node = of_find_node_by_path("/ibm,opal");
 433         if (!opal_node) {
 434                 pr_warn("opal: Node not found\n");
 435                 return -ENODEV;
 436         }
 437
 438         /* Register OPAL consoles if any ports */
 439         if (firmware_has_feature(FW_FEATURE_OPALv2))
 440                 consoles = of_find_node_by_path("/ibm,opal/consoles");
 441         else
 442                 consoles = of_node_get(opal_node);
 443         if (consoles) {
 444                 for_each_child_of_node(consoles, np) {
 445                         if (strcmp(np->name, "serial"))
 446                                 continue;
 447                         of_platform_device_create(np, NULL, NULL);
 448                 }
 449                 of_node_put(consoles);
 450         }
 451
 452         /* Find all OPAL interrupts and request them */
 453         irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);
 454         pr_debug("opal: Found %d interrupts reserved for OPAL\n",
 455                  irqs ? (irqlen / 4) : 0);
 456         opal_irq_count = irqlen / 4;
 457         opal_irqs = kzalloc(opal_irq_count * sizeof(unsigned int), GFP_KERNEL);
 458         for (i = 0; irqs && i < (irqlen / 4); i++, irqs++) {
 459                 unsigned int hwirq = be32_to_cpup(irqs);
 460                 unsigned int irq = irq_create_mapping(NULL, hwirq);
 461                 if (irq == NO_IRQ) {
 462                         pr_warning("opal: Failed to map irq 0x%x\n", hwirq);
 463                         continue;
 464                 }
 465                 rc = request_irq(irq, opal_interrupt, 0, "opal", NULL);
 466                 if (rc)
 467                         pr_warning("opal: Error %d requesting irq %d"
 468                                    " (0x%x)\n", rc, irq, hwirq);
 469                 opal_irqs[i] = irq;
 470         }
 471
 472         /* Create "opal" kobject under /sys/firmware */
 473         rc = opal_sysfs_init();
 474         if (rc == 0) {
 475                 /* Setup code update interface */
 476                 opal_flash_init();
 477         }
 478
 479         return 0;
 480 }
 481 subsys_initcall(opal_init);
 482
 483 void opal_shutdown(void)
 484 {
 485         unsigned int i;
 486         long rc = OPAL_BUSY;
 487
 488         /* First free interrupts, which will also mask them */
 489         for (i = 0; i < opal_irq_count; i++) {
 490                 if (opal_irqs[i])
 491                         free_irq(opal_irqs[i], NULL);
 492                 opal_irqs[i] = 0;
 493         }
 494
 495         /*
 496          * Then sync with OPAL which ensure anything that can
 497          * potentially write to our memory has completed such
 498          * as an ongoing dump retrieval
 499          */
 500         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 501                 rc = opal_sync_host_reboot();
 502                 if (rc == OPAL_BUSY)
 503                         opal_poll_events(NULL);
 504                 else
 505                         mdelay(10);
 506         }
 507 }