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