1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * core function to access sclp interface 4 * 5 * Copyright IBM Corp. 1999, 2009 6 * 7 * Author(s): Martin Peschke <mpeschke@de.ibm.com> 8 * Martin Schwidefsky <schwidefsky@de.ibm.com> 9 */ 10 11 #include <linux/kernel_stat.h> 12 #include <linux/module.h> 13 #include <linux/err.h> 14 #include <linux/panic_notifier.h> 15 #include <linux/spinlock.h> 16 #include <linux/interrupt.h> 17 #include <linux/timer.h> 18 #include <linux/reboot.h> 19 #include <linux/jiffies.h> 20 #include <linux/init.h> 21 #include <linux/suspend.h> 22 #include <linux/completion.h> 23 #include <linux/platform_device.h> 24 #include <asm/types.h> 25 #include <asm/irq.h> 26 27 #include "sclp.h" 28 29 #define SCLP_HEADER "sclp: " 30 31 /* Lock to protect internal data consistency. */ 32 static DEFINE_SPINLOCK(sclp_lock); 33 34 /* Mask of events that we can send to the sclp interface. */ 35 static sccb_mask_t sclp_receive_mask; 36 37 /* Mask of events that we can receive from the sclp interface. */ 38 static sccb_mask_t sclp_send_mask; 39 40 /* List of registered event listeners and senders. */ 41 static LIST_HEAD(sclp_reg_list); 42 43 /* List of queued requests. */ 44 static LIST_HEAD(sclp_req_queue); 45 46 /* Data for read and and init requests. */ 47 static struct sclp_req sclp_read_req; 48 static struct sclp_req sclp_init_req; 49 static void *sclp_read_sccb; 50 static struct init_sccb *sclp_init_sccb; 51 52 /* Suspend request */ 53 static DECLARE_COMPLETION(sclp_request_queue_flushed); 54 55 /* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */ 56 int sclp_console_pages = SCLP_CONSOLE_PAGES; 57 /* Flag to indicate if buffer pages are dropped on buffer full condition */ 58 int sclp_console_drop = 1; 59 /* Number of times the console dropped buffer pages */ 60 unsigned long sclp_console_full; 61 62 static void sclp_suspend_req_cb(struct sclp_req *req, void *data) 63 { 64 complete(&sclp_request_queue_flushed); 65 } 66 67 static int __init sclp_setup_console_pages(char *str) 68 { 69 int pages, rc; 70 71 rc = kstrtoint(str, 0, &pages); 72 if (!rc && pages >= SCLP_CONSOLE_PAGES) 73 sclp_console_pages = pages; 74 return 1; 75 } 76 77 __setup("sclp_con_pages=", sclp_setup_console_pages); 78 79 static int __init sclp_setup_console_drop(char *str) 80 { 81 int drop, rc; 82 83 rc = kstrtoint(str, 0, &drop); 84 if (!rc) 85 sclp_console_drop = drop; 86 return 1; 87 } 88 89 __setup("sclp_con_drop=", sclp_setup_console_drop); 90 91 static struct sclp_req sclp_suspend_req; 92 93 /* Timer for request retries. */ 94 static struct timer_list sclp_request_timer; 95 96 /* Timer for queued requests. */ 97 static struct timer_list sclp_queue_timer; 98 99 /* Internal state: is a request active at the sclp? */ 100 static volatile enum sclp_running_state_t { 101 sclp_running_state_idle, 102 sclp_running_state_running, 103 sclp_running_state_reset_pending 104 } sclp_running_state = sclp_running_state_idle; 105 106 /* Internal state: is a read request pending? */ 107 static volatile enum sclp_reading_state_t { 108 sclp_reading_state_idle, 109 sclp_reading_state_reading 110 } sclp_reading_state = sclp_reading_state_idle; 111 112 /* Internal state: is the driver currently serving requests? */ 113 static volatile enum sclp_activation_state_t { 114 sclp_activation_state_active, 115 sclp_activation_state_deactivating, 116 sclp_activation_state_inactive, 117 sclp_activation_state_activating 118 } sclp_activation_state = sclp_activation_state_active; 119 120 /* Internal state: is an init mask request pending? */ 121 static volatile enum sclp_mask_state_t { 122 sclp_mask_state_idle, 123 sclp_mask_state_initializing 124 } sclp_mask_state = sclp_mask_state_idle; 125 126 /* Internal state: is the driver suspended? */ 127 static enum sclp_suspend_state_t { 128 sclp_suspend_state_running, 129 sclp_suspend_state_suspended, 130 } sclp_suspend_state = sclp_suspend_state_running; 131 132 /* Maximum retry counts */ 133 #define SCLP_INIT_RETRY 3 134 #define SCLP_MASK_RETRY 3 135 136 /* Timeout intervals in seconds.*/ 137 #define SCLP_BUSY_INTERVAL 10 138 #define SCLP_RETRY_INTERVAL 30 139 140 static void sclp_request_timeout(bool force_restart); 141 static void sclp_process_queue(void); 142 static void __sclp_make_read_req(void); 143 static int sclp_init_mask(int calculate); 144 static int sclp_init(void); 145 146 static void 147 __sclp_queue_read_req(void) 148 { 149 if (sclp_reading_state == sclp_reading_state_idle) { 150 sclp_reading_state = sclp_reading_state_reading; 151 __sclp_make_read_req(); 152 /* Add request to head of queue */ 153 list_add(&sclp_read_req.list, &sclp_req_queue); 154 } 155 } 156 157 /* Set up request retry timer. Called while sclp_lock is locked. */ 158 static inline void 159 __sclp_set_request_timer(unsigned long time, void (*cb)(struct timer_list *)) 160 { 161 del_timer(&sclp_request_timer); 162 sclp_request_timer.function = cb; 163 sclp_request_timer.expires = jiffies + time; 164 add_timer(&sclp_request_timer); 165 } 166 167 static void sclp_request_timeout_restart(struct timer_list *unused) 168 { 169 sclp_request_timeout(true); 170 } 171 172 static void sclp_request_timeout_normal(struct timer_list *unused) 173 { 174 sclp_request_timeout(false); 175 } 176 177 /* Request timeout handler. Restart the request queue. If force_restart, 178 * force restart of running request. */ 179 static void sclp_request_timeout(bool force_restart) 180 { 181 unsigned long flags; 182 183 spin_lock_irqsave(&sclp_lock, flags); 184 if (force_restart) { 185 if (sclp_running_state == sclp_running_state_running) { 186 /* Break running state and queue NOP read event request 187 * to get a defined interface state. */ 188 __sclp_queue_read_req(); 189 sclp_running_state = sclp_running_state_idle; 190 } 191 } else { 192 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 193 sclp_request_timeout_normal); 194 } 195 spin_unlock_irqrestore(&sclp_lock, flags); 196 sclp_process_queue(); 197 } 198 199 /* 200 * Returns the expire value in jiffies of the next pending request timeout, 201 * if any. Needs to be called with sclp_lock. 202 */ 203 static unsigned long __sclp_req_queue_find_next_timeout(void) 204 { 205 unsigned long expires_next = 0; 206 struct sclp_req *req; 207 208 list_for_each_entry(req, &sclp_req_queue, list) { 209 if (!req->queue_expires) 210 continue; 211 if (!expires_next || 212 (time_before(req->queue_expires, expires_next))) 213 expires_next = req->queue_expires; 214 } 215 return expires_next; 216 } 217 218 /* 219 * Returns expired request, if any, and removes it from the list. 220 */ 221 static struct sclp_req *__sclp_req_queue_remove_expired_req(void) 222 { 223 unsigned long flags, now; 224 struct sclp_req *req; 225 226 spin_lock_irqsave(&sclp_lock, flags); 227 now = jiffies; 228 /* Don't need list_for_each_safe because we break out after list_del */ 229 list_for_each_entry(req, &sclp_req_queue, list) { 230 if (!req->queue_expires) 231 continue; 232 if (time_before_eq(req->queue_expires, now)) { 233 if (req->status == SCLP_REQ_QUEUED) { 234 req->status = SCLP_REQ_QUEUED_TIMEOUT; 235 list_del(&req->list); 236 goto out; 237 } 238 } 239 } 240 req = NULL; 241 out: 242 spin_unlock_irqrestore(&sclp_lock, flags); 243 return req; 244 } 245 246 /* 247 * Timeout handler for queued requests. Removes request from list and 248 * invokes callback. This timer can be set per request in situations where 249 * waiting too long would be harmful to the system, e.g. during SE reboot. 250 */ 251 static void sclp_req_queue_timeout(struct timer_list *unused) 252 { 253 unsigned long flags, expires_next; 254 struct sclp_req *req; 255 256 do { 257 req = __sclp_req_queue_remove_expired_req(); 258 if (req && req->callback) 259 req->callback(req, req->callback_data); 260 } while (req); 261 262 spin_lock_irqsave(&sclp_lock, flags); 263 expires_next = __sclp_req_queue_find_next_timeout(); 264 if (expires_next) 265 mod_timer(&sclp_queue_timer, expires_next); 266 spin_unlock_irqrestore(&sclp_lock, flags); 267 } 268 269 /* Try to start a request. Return zero if the request was successfully 270 * started or if it will be started at a later time. Return non-zero otherwise. 271 * Called while sclp_lock is locked. */ 272 static int 273 __sclp_start_request(struct sclp_req *req) 274 { 275 int rc; 276 277 if (sclp_running_state != sclp_running_state_idle) 278 return 0; 279 del_timer(&sclp_request_timer); 280 rc = sclp_service_call(req->command, req->sccb); 281 req->start_count++; 282 283 if (rc == 0) { 284 /* Successfully started request */ 285 req->status = SCLP_REQ_RUNNING; 286 sclp_running_state = sclp_running_state_running; 287 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 288 sclp_request_timeout_restart); 289 return 0; 290 } else if (rc == -EBUSY) { 291 /* Try again later */ 292 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 293 sclp_request_timeout_normal); 294 return 0; 295 } 296 /* Request failed */ 297 req->status = SCLP_REQ_FAILED; 298 return rc; 299 } 300 301 /* Try to start queued requests. */ 302 static void 303 sclp_process_queue(void) 304 { 305 struct sclp_req *req; 306 int rc; 307 unsigned long flags; 308 309 spin_lock_irqsave(&sclp_lock, flags); 310 if (sclp_running_state != sclp_running_state_idle) { 311 spin_unlock_irqrestore(&sclp_lock, flags); 312 return; 313 } 314 del_timer(&sclp_request_timer); 315 while (!list_empty(&sclp_req_queue)) { 316 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 317 if (!req->sccb) 318 goto do_post; 319 rc = __sclp_start_request(req); 320 if (rc == 0) 321 break; 322 /* Request failed */ 323 if (req->start_count > 1) { 324 /* Cannot abort already submitted request - could still 325 * be active at the SCLP */ 326 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 327 sclp_request_timeout_normal); 328 break; 329 } 330 do_post: 331 /* Post-processing for aborted request */ 332 list_del(&req->list); 333 if (req->callback) { 334 spin_unlock_irqrestore(&sclp_lock, flags); 335 req->callback(req, req->callback_data); 336 spin_lock_irqsave(&sclp_lock, flags); 337 } 338 } 339 spin_unlock_irqrestore(&sclp_lock, flags); 340 } 341 342 static int __sclp_can_add_request(struct sclp_req *req) 343 { 344 if (req == &sclp_suspend_req || req == &sclp_init_req) 345 return 1; 346 if (sclp_suspend_state != sclp_suspend_state_running) 347 return 0; 348 if (sclp_init_state != sclp_init_state_initialized) 349 return 0; 350 if (sclp_activation_state != sclp_activation_state_active) 351 return 0; 352 return 1; 353 } 354 355 /* Queue a new request. Return zero on success, non-zero otherwise. */ 356 int 357 sclp_add_request(struct sclp_req *req) 358 { 359 unsigned long flags; 360 int rc; 361 362 spin_lock_irqsave(&sclp_lock, flags); 363 if (!__sclp_can_add_request(req)) { 364 spin_unlock_irqrestore(&sclp_lock, flags); 365 return -EIO; 366 } 367 req->status = SCLP_REQ_QUEUED; 368 req->start_count = 0; 369 list_add_tail(&req->list, &sclp_req_queue); 370 rc = 0; 371 if (req->queue_timeout) { 372 req->queue_expires = jiffies + req->queue_timeout * HZ; 373 if (!timer_pending(&sclp_queue_timer) || 374 time_after(sclp_queue_timer.expires, req->queue_expires)) 375 mod_timer(&sclp_queue_timer, req->queue_expires); 376 } else 377 req->queue_expires = 0; 378 /* Start if request is first in list */ 379 if (sclp_running_state == sclp_running_state_idle && 380 req->list.prev == &sclp_req_queue) { 381 if (!req->sccb) { 382 list_del(&req->list); 383 rc = -ENODATA; 384 goto out; 385 } 386 rc = __sclp_start_request(req); 387 if (rc) 388 list_del(&req->list); 389 } 390 out: 391 spin_unlock_irqrestore(&sclp_lock, flags); 392 return rc; 393 } 394 395 EXPORT_SYMBOL(sclp_add_request); 396 397 /* Dispatch events found in request buffer to registered listeners. Return 0 398 * if all events were dispatched, non-zero otherwise. */ 399 static int 400 sclp_dispatch_evbufs(struct sccb_header *sccb) 401 { 402 unsigned long flags; 403 struct evbuf_header *evbuf; 404 struct list_head *l; 405 struct sclp_register *reg; 406 int offset; 407 int rc; 408 409 spin_lock_irqsave(&sclp_lock, flags); 410 rc = 0; 411 for (offset = sizeof(struct sccb_header); offset < sccb->length; 412 offset += evbuf->length) { 413 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 414 /* Check for malformed hardware response */ 415 if (evbuf->length == 0) 416 break; 417 /* Search for event handler */ 418 reg = NULL; 419 list_for_each(l, &sclp_reg_list) { 420 reg = list_entry(l, struct sclp_register, list); 421 if (reg->receive_mask & SCLP_EVTYP_MASK(evbuf->type)) 422 break; 423 else 424 reg = NULL; 425 } 426 if (reg && reg->receiver_fn) { 427 spin_unlock_irqrestore(&sclp_lock, flags); 428 reg->receiver_fn(evbuf); 429 spin_lock_irqsave(&sclp_lock, flags); 430 } else if (reg == NULL) 431 rc = -EOPNOTSUPP; 432 } 433 spin_unlock_irqrestore(&sclp_lock, flags); 434 return rc; 435 } 436 437 /* Read event data request callback. */ 438 static void 439 sclp_read_cb(struct sclp_req *req, void *data) 440 { 441 unsigned long flags; 442 struct sccb_header *sccb; 443 444 sccb = (struct sccb_header *) req->sccb; 445 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 446 sccb->response_code == 0x220)) 447 sclp_dispatch_evbufs(sccb); 448 spin_lock_irqsave(&sclp_lock, flags); 449 sclp_reading_state = sclp_reading_state_idle; 450 spin_unlock_irqrestore(&sclp_lock, flags); 451 } 452 453 /* Prepare read event data request. Called while sclp_lock is locked. */ 454 static void __sclp_make_read_req(void) 455 { 456 struct sccb_header *sccb; 457 458 sccb = (struct sccb_header *) sclp_read_sccb; 459 clear_page(sccb); 460 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 461 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 462 sclp_read_req.status = SCLP_REQ_QUEUED; 463 sclp_read_req.start_count = 0; 464 sclp_read_req.callback = sclp_read_cb; 465 sclp_read_req.sccb = sccb; 466 sccb->length = PAGE_SIZE; 467 sccb->function_code = 0; 468 sccb->control_mask[2] = 0x80; 469 } 470 471 /* Search request list for request with matching sccb. Return request if found, 472 * NULL otherwise. Called while sclp_lock is locked. */ 473 static inline struct sclp_req * 474 __sclp_find_req(u32 sccb) 475 { 476 struct list_head *l; 477 struct sclp_req *req; 478 479 list_for_each(l, &sclp_req_queue) { 480 req = list_entry(l, struct sclp_req, list); 481 if (sccb == (u32) (addr_t) req->sccb) 482 return req; 483 } 484 return NULL; 485 } 486 487 /* Handler for external interruption. Perform request post-processing. 488 * Prepare read event data request if necessary. Start processing of next 489 * request on queue. */ 490 static void sclp_interrupt_handler(struct ext_code ext_code, 491 unsigned int param32, unsigned long param64) 492 { 493 struct sclp_req *req; 494 u32 finished_sccb; 495 u32 evbuf_pending; 496 497 inc_irq_stat(IRQEXT_SCP); 498 spin_lock(&sclp_lock); 499 finished_sccb = param32 & 0xfffffff8; 500 evbuf_pending = param32 & 0x3; 501 if (finished_sccb) { 502 del_timer(&sclp_request_timer); 503 sclp_running_state = sclp_running_state_reset_pending; 504 req = __sclp_find_req(finished_sccb); 505 if (req) { 506 /* Request post-processing */ 507 list_del(&req->list); 508 req->status = SCLP_REQ_DONE; 509 if (req->callback) { 510 spin_unlock(&sclp_lock); 511 req->callback(req, req->callback_data); 512 spin_lock(&sclp_lock); 513 } 514 } 515 sclp_running_state = sclp_running_state_idle; 516 } 517 if (evbuf_pending && 518 sclp_activation_state == sclp_activation_state_active) 519 __sclp_queue_read_req(); 520 spin_unlock(&sclp_lock); 521 sclp_process_queue(); 522 } 523 524 /* Convert interval in jiffies to TOD ticks. */ 525 static inline u64 526 sclp_tod_from_jiffies(unsigned long jiffies) 527 { 528 return (u64) (jiffies / HZ) << 32; 529 } 530 531 /* Wait until a currently running request finished. Note: while this function 532 * is running, no timers are served on the calling CPU. */ 533 void 534 sclp_sync_wait(void) 535 { 536 unsigned long long old_tick; 537 unsigned long flags; 538 unsigned long cr0, cr0_sync; 539 u64 timeout; 540 int irq_context; 541 542 /* We'll be disabling timer interrupts, so we need a custom timeout 543 * mechanism */ 544 timeout = 0; 545 if (timer_pending(&sclp_request_timer)) { 546 /* Get timeout TOD value */ 547 timeout = get_tod_clock_fast() + 548 sclp_tod_from_jiffies(sclp_request_timer.expires - 549 jiffies); 550 } 551 local_irq_save(flags); 552 /* Prevent bottom half from executing once we force interrupts open */ 553 irq_context = in_interrupt(); 554 if (!irq_context) 555 local_bh_disable(); 556 /* Enable service-signal interruption, disable timer interrupts */ 557 old_tick = local_tick_disable(); 558 trace_hardirqs_on(); 559 __ctl_store(cr0, 0, 0); 560 cr0_sync = cr0 & ~CR0_IRQ_SUBCLASS_MASK; 561 cr0_sync |= 1UL << (63 - 54); 562 __ctl_load(cr0_sync, 0, 0); 563 __arch_local_irq_stosm(0x01); 564 /* Loop until driver state indicates finished request */ 565 while (sclp_running_state != sclp_running_state_idle) { 566 /* Check for expired request timer */ 567 if (timer_pending(&sclp_request_timer) && 568 get_tod_clock_fast() > timeout && 569 del_timer(&sclp_request_timer)) 570 sclp_request_timer.function(&sclp_request_timer); 571 cpu_relax(); 572 } 573 local_irq_disable(); 574 __ctl_load(cr0, 0, 0); 575 if (!irq_context) 576 _local_bh_enable(); 577 local_tick_enable(old_tick); 578 local_irq_restore(flags); 579 } 580 EXPORT_SYMBOL(sclp_sync_wait); 581 582 /* Dispatch changes in send and receive mask to registered listeners. */ 583 static void 584 sclp_dispatch_state_change(void) 585 { 586 struct list_head *l; 587 struct sclp_register *reg; 588 unsigned long flags; 589 sccb_mask_t receive_mask; 590 sccb_mask_t send_mask; 591 592 do { 593 spin_lock_irqsave(&sclp_lock, flags); 594 reg = NULL; 595 list_for_each(l, &sclp_reg_list) { 596 reg = list_entry(l, struct sclp_register, list); 597 receive_mask = reg->send_mask & sclp_receive_mask; 598 send_mask = reg->receive_mask & sclp_send_mask; 599 if (reg->sclp_receive_mask != receive_mask || 600 reg->sclp_send_mask != send_mask) { 601 reg->sclp_receive_mask = receive_mask; 602 reg->sclp_send_mask = send_mask; 603 break; 604 } else 605 reg = NULL; 606 } 607 spin_unlock_irqrestore(&sclp_lock, flags); 608 if (reg && reg->state_change_fn) 609 reg->state_change_fn(reg); 610 } while (reg); 611 } 612 613 struct sclp_statechangebuf { 614 struct evbuf_header header; 615 u8 validity_sclp_active_facility_mask : 1; 616 u8 validity_sclp_receive_mask : 1; 617 u8 validity_sclp_send_mask : 1; 618 u8 validity_read_data_function_mask : 1; 619 u16 _zeros : 12; 620 u16 mask_length; 621 u64 sclp_active_facility_mask; 622 u8 masks[2 * 1021 + 4]; /* variable length */ 623 /* 624 * u8 sclp_receive_mask[mask_length]; 625 * u8 sclp_send_mask[mask_length]; 626 * u32 read_data_function_mask; 627 */ 628 } __attribute__((packed)); 629 630 631 /* State change event callback. Inform listeners of changes. */ 632 static void 633 sclp_state_change_cb(struct evbuf_header *evbuf) 634 { 635 unsigned long flags; 636 struct sclp_statechangebuf *scbuf; 637 638 BUILD_BUG_ON(sizeof(struct sclp_statechangebuf) > PAGE_SIZE); 639 640 scbuf = (struct sclp_statechangebuf *) evbuf; 641 spin_lock_irqsave(&sclp_lock, flags); 642 if (scbuf->validity_sclp_receive_mask) 643 sclp_receive_mask = sccb_get_recv_mask(scbuf); 644 if (scbuf->validity_sclp_send_mask) 645 sclp_send_mask = sccb_get_send_mask(scbuf); 646 spin_unlock_irqrestore(&sclp_lock, flags); 647 if (scbuf->validity_sclp_active_facility_mask) 648 sclp.facilities = scbuf->sclp_active_facility_mask; 649 sclp_dispatch_state_change(); 650 } 651 652 static struct sclp_register sclp_state_change_event = { 653 .receive_mask = EVTYP_STATECHANGE_MASK, 654 .receiver_fn = sclp_state_change_cb 655 }; 656 657 /* Calculate receive and send mask of currently registered listeners. 658 * Called while sclp_lock is locked. */ 659 static inline void 660 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 661 { 662 struct list_head *l; 663 struct sclp_register *t; 664 665 *receive_mask = 0; 666 *send_mask = 0; 667 list_for_each(l, &sclp_reg_list) { 668 t = list_entry(l, struct sclp_register, list); 669 *receive_mask |= t->receive_mask; 670 *send_mask |= t->send_mask; 671 } 672 } 673 674 /* Register event listener. Return 0 on success, non-zero otherwise. */ 675 int 676 sclp_register(struct sclp_register *reg) 677 { 678 unsigned long flags; 679 sccb_mask_t receive_mask; 680 sccb_mask_t send_mask; 681 int rc; 682 683 rc = sclp_init(); 684 if (rc) 685 return rc; 686 spin_lock_irqsave(&sclp_lock, flags); 687 /* Check event mask for collisions */ 688 __sclp_get_mask(&receive_mask, &send_mask); 689 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 690 spin_unlock_irqrestore(&sclp_lock, flags); 691 return -EBUSY; 692 } 693 /* Trigger initial state change callback */ 694 reg->sclp_receive_mask = 0; 695 reg->sclp_send_mask = 0; 696 reg->pm_event_posted = 0; 697 list_add(®->list, &sclp_reg_list); 698 spin_unlock_irqrestore(&sclp_lock, flags); 699 rc = sclp_init_mask(1); 700 if (rc) { 701 spin_lock_irqsave(&sclp_lock, flags); 702 list_del(®->list); 703 spin_unlock_irqrestore(&sclp_lock, flags); 704 } 705 return rc; 706 } 707 708 EXPORT_SYMBOL(sclp_register); 709 710 /* Unregister event listener. */ 711 void 712 sclp_unregister(struct sclp_register *reg) 713 { 714 unsigned long flags; 715 716 spin_lock_irqsave(&sclp_lock, flags); 717 list_del(®->list); 718 spin_unlock_irqrestore(&sclp_lock, flags); 719 sclp_init_mask(1); 720 } 721 722 EXPORT_SYMBOL(sclp_unregister); 723 724 /* Remove event buffers which are marked processed. Return the number of 725 * remaining event buffers. */ 726 int 727 sclp_remove_processed(struct sccb_header *sccb) 728 { 729 struct evbuf_header *evbuf; 730 int unprocessed; 731 u16 remaining; 732 733 evbuf = (struct evbuf_header *) (sccb + 1); 734 unprocessed = 0; 735 remaining = sccb->length - sizeof(struct sccb_header); 736 while (remaining > 0) { 737 remaining -= evbuf->length; 738 if (evbuf->flags & 0x80) { 739 sccb->length -= evbuf->length; 740 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 741 remaining); 742 } else { 743 unprocessed++; 744 evbuf = (struct evbuf_header *) 745 ((addr_t) evbuf + evbuf->length); 746 } 747 } 748 return unprocessed; 749 } 750 751 EXPORT_SYMBOL(sclp_remove_processed); 752 753 /* Prepare init mask request. Called while sclp_lock is locked. */ 754 static inline void 755 __sclp_make_init_req(sccb_mask_t receive_mask, sccb_mask_t send_mask) 756 { 757 struct init_sccb *sccb = sclp_init_sccb; 758 759 clear_page(sccb); 760 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 761 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 762 sclp_init_req.status = SCLP_REQ_FILLED; 763 sclp_init_req.start_count = 0; 764 sclp_init_req.callback = NULL; 765 sclp_init_req.callback_data = NULL; 766 sclp_init_req.sccb = sccb; 767 sccb->header.length = sizeof(*sccb); 768 if (sclp_mask_compat_mode) 769 sccb->mask_length = SCLP_MASK_SIZE_COMPAT; 770 else 771 sccb->mask_length = sizeof(sccb_mask_t); 772 sccb_set_recv_mask(sccb, receive_mask); 773 sccb_set_send_mask(sccb, send_mask); 774 sccb_set_sclp_recv_mask(sccb, 0); 775 sccb_set_sclp_send_mask(sccb, 0); 776 } 777 778 /* Start init mask request. If calculate is non-zero, calculate the mask as 779 * requested by registered listeners. Use zero mask otherwise. Return 0 on 780 * success, non-zero otherwise. */ 781 static int 782 sclp_init_mask(int calculate) 783 { 784 unsigned long flags; 785 struct init_sccb *sccb = sclp_init_sccb; 786 sccb_mask_t receive_mask; 787 sccb_mask_t send_mask; 788 int retry; 789 int rc; 790 unsigned long wait; 791 792 spin_lock_irqsave(&sclp_lock, flags); 793 /* Check if interface is in appropriate state */ 794 if (sclp_mask_state != sclp_mask_state_idle) { 795 spin_unlock_irqrestore(&sclp_lock, flags); 796 return -EBUSY; 797 } 798 if (sclp_activation_state == sclp_activation_state_inactive) { 799 spin_unlock_irqrestore(&sclp_lock, flags); 800 return -EINVAL; 801 } 802 sclp_mask_state = sclp_mask_state_initializing; 803 /* Determine mask */ 804 if (calculate) 805 __sclp_get_mask(&receive_mask, &send_mask); 806 else { 807 receive_mask = 0; 808 send_mask = 0; 809 } 810 rc = -EIO; 811 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 812 /* Prepare request */ 813 __sclp_make_init_req(receive_mask, send_mask); 814 spin_unlock_irqrestore(&sclp_lock, flags); 815 if (sclp_add_request(&sclp_init_req)) { 816 /* Try again later */ 817 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 818 while (time_before(jiffies, wait)) 819 sclp_sync_wait(); 820 spin_lock_irqsave(&sclp_lock, flags); 821 continue; 822 } 823 while (sclp_init_req.status != SCLP_REQ_DONE && 824 sclp_init_req.status != SCLP_REQ_FAILED) 825 sclp_sync_wait(); 826 spin_lock_irqsave(&sclp_lock, flags); 827 if (sclp_init_req.status == SCLP_REQ_DONE && 828 sccb->header.response_code == 0x20) { 829 /* Successful request */ 830 if (calculate) { 831 sclp_receive_mask = sccb_get_sclp_recv_mask(sccb); 832 sclp_send_mask = sccb_get_sclp_send_mask(sccb); 833 } else { 834 sclp_receive_mask = 0; 835 sclp_send_mask = 0; 836 } 837 spin_unlock_irqrestore(&sclp_lock, flags); 838 sclp_dispatch_state_change(); 839 spin_lock_irqsave(&sclp_lock, flags); 840 rc = 0; 841 break; 842 } 843 } 844 sclp_mask_state = sclp_mask_state_idle; 845 spin_unlock_irqrestore(&sclp_lock, flags); 846 return rc; 847 } 848 849 /* Deactivate SCLP interface. On success, new requests will be rejected, 850 * events will no longer be dispatched. Return 0 on success, non-zero 851 * otherwise. */ 852 int 853 sclp_deactivate(void) 854 { 855 unsigned long flags; 856 int rc; 857 858 spin_lock_irqsave(&sclp_lock, flags); 859 /* Deactivate can only be called when active */ 860 if (sclp_activation_state != sclp_activation_state_active) { 861 spin_unlock_irqrestore(&sclp_lock, flags); 862 return -EINVAL; 863 } 864 sclp_activation_state = sclp_activation_state_deactivating; 865 spin_unlock_irqrestore(&sclp_lock, flags); 866 rc = sclp_init_mask(0); 867 spin_lock_irqsave(&sclp_lock, flags); 868 if (rc == 0) 869 sclp_activation_state = sclp_activation_state_inactive; 870 else 871 sclp_activation_state = sclp_activation_state_active; 872 spin_unlock_irqrestore(&sclp_lock, flags); 873 return rc; 874 } 875 876 EXPORT_SYMBOL(sclp_deactivate); 877 878 /* Reactivate SCLP interface after sclp_deactivate. On success, new 879 * requests will be accepted, events will be dispatched again. Return 0 on 880 * success, non-zero otherwise. */ 881 int 882 sclp_reactivate(void) 883 { 884 unsigned long flags; 885 int rc; 886 887 spin_lock_irqsave(&sclp_lock, flags); 888 /* Reactivate can only be called when inactive */ 889 if (sclp_activation_state != sclp_activation_state_inactive) { 890 spin_unlock_irqrestore(&sclp_lock, flags); 891 return -EINVAL; 892 } 893 sclp_activation_state = sclp_activation_state_activating; 894 spin_unlock_irqrestore(&sclp_lock, flags); 895 rc = sclp_init_mask(1); 896 spin_lock_irqsave(&sclp_lock, flags); 897 if (rc == 0) 898 sclp_activation_state = sclp_activation_state_active; 899 else 900 sclp_activation_state = sclp_activation_state_inactive; 901 spin_unlock_irqrestore(&sclp_lock, flags); 902 return rc; 903 } 904 905 EXPORT_SYMBOL(sclp_reactivate); 906 907 /* Handler for external interruption used during initialization. Modify 908 * request state to done. */ 909 static void sclp_check_handler(struct ext_code ext_code, 910 unsigned int param32, unsigned long param64) 911 { 912 u32 finished_sccb; 913 914 inc_irq_stat(IRQEXT_SCP); 915 finished_sccb = param32 & 0xfffffff8; 916 /* Is this the interrupt we are waiting for? */ 917 if (finished_sccb == 0) 918 return; 919 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) 920 panic("sclp: unsolicited interrupt for buffer at 0x%x\n", 921 finished_sccb); 922 spin_lock(&sclp_lock); 923 if (sclp_running_state == sclp_running_state_running) { 924 sclp_init_req.status = SCLP_REQ_DONE; 925 sclp_running_state = sclp_running_state_idle; 926 } 927 spin_unlock(&sclp_lock); 928 } 929 930 /* Initial init mask request timed out. Modify request state to failed. */ 931 static void 932 sclp_check_timeout(struct timer_list *unused) 933 { 934 unsigned long flags; 935 936 spin_lock_irqsave(&sclp_lock, flags); 937 if (sclp_running_state == sclp_running_state_running) { 938 sclp_init_req.status = SCLP_REQ_FAILED; 939 sclp_running_state = sclp_running_state_idle; 940 } 941 spin_unlock_irqrestore(&sclp_lock, flags); 942 } 943 944 /* Perform a check of the SCLP interface. Return zero if the interface is 945 * available and there are no pending requests from a previous instance. 946 * Return non-zero otherwise. */ 947 static int 948 sclp_check_interface(void) 949 { 950 struct init_sccb *sccb; 951 unsigned long flags; 952 int retry; 953 int rc; 954 955 spin_lock_irqsave(&sclp_lock, flags); 956 /* Prepare init mask command */ 957 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); 958 if (rc) { 959 spin_unlock_irqrestore(&sclp_lock, flags); 960 return rc; 961 } 962 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 963 __sclp_make_init_req(0, 0); 964 sccb = (struct init_sccb *) sclp_init_req.sccb; 965 rc = sclp_service_call(sclp_init_req.command, sccb); 966 if (rc == -EIO) 967 break; 968 sclp_init_req.status = SCLP_REQ_RUNNING; 969 sclp_running_state = sclp_running_state_running; 970 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 971 sclp_check_timeout); 972 spin_unlock_irqrestore(&sclp_lock, flags); 973 /* Enable service-signal interruption - needs to happen 974 * with IRQs enabled. */ 975 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 976 /* Wait for signal from interrupt or timeout */ 977 sclp_sync_wait(); 978 /* Disable service-signal interruption - needs to happen 979 * with IRQs enabled. */ 980 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); 981 spin_lock_irqsave(&sclp_lock, flags); 982 del_timer(&sclp_request_timer); 983 rc = -EBUSY; 984 if (sclp_init_req.status == SCLP_REQ_DONE) { 985 if (sccb->header.response_code == 0x20) { 986 rc = 0; 987 break; 988 } else if (sccb->header.response_code == 0x74f0) { 989 if (!sclp_mask_compat_mode) { 990 sclp_mask_compat_mode = true; 991 retry = 0; 992 } 993 } 994 } 995 } 996 unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); 997 spin_unlock_irqrestore(&sclp_lock, flags); 998 return rc; 999 } 1000 1001 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP 1002 * events from interfering with rebooted system. */ 1003 static int 1004 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 1005 { 1006 sclp_deactivate(); 1007 return NOTIFY_DONE; 1008 } 1009 1010 static struct notifier_block sclp_reboot_notifier = { 1011 .notifier_call = sclp_reboot_event 1012 }; 1013 1014 /* 1015 * Suspend/resume SCLP notifier implementation 1016 */ 1017 1018 static void sclp_pm_event(enum sclp_pm_event sclp_pm_event, int rollback) 1019 { 1020 struct sclp_register *reg; 1021 unsigned long flags; 1022 1023 if (!rollback) { 1024 spin_lock_irqsave(&sclp_lock, flags); 1025 list_for_each_entry(reg, &sclp_reg_list, list) 1026 reg->pm_event_posted = 0; 1027 spin_unlock_irqrestore(&sclp_lock, flags); 1028 } 1029 do { 1030 spin_lock_irqsave(&sclp_lock, flags); 1031 list_for_each_entry(reg, &sclp_reg_list, list) { 1032 if (rollback && reg->pm_event_posted) 1033 goto found; 1034 if (!rollback && !reg->pm_event_posted) 1035 goto found; 1036 } 1037 spin_unlock_irqrestore(&sclp_lock, flags); 1038 return; 1039 found: 1040 spin_unlock_irqrestore(&sclp_lock, flags); 1041 if (reg->pm_event_fn) 1042 reg->pm_event_fn(reg, sclp_pm_event); 1043 reg->pm_event_posted = rollback ? 0 : 1; 1044 } while (1); 1045 } 1046 1047 /* 1048 * Susend/resume callbacks for platform device 1049 */ 1050 1051 static int sclp_freeze(struct device *dev) 1052 { 1053 unsigned long flags; 1054 int rc; 1055 1056 sclp_pm_event(SCLP_PM_EVENT_FREEZE, 0); 1057 1058 spin_lock_irqsave(&sclp_lock, flags); 1059 sclp_suspend_state = sclp_suspend_state_suspended; 1060 spin_unlock_irqrestore(&sclp_lock, flags); 1061 1062 /* Init supend data */ 1063 memset(&sclp_suspend_req, 0, sizeof(sclp_suspend_req)); 1064 sclp_suspend_req.callback = sclp_suspend_req_cb; 1065 sclp_suspend_req.status = SCLP_REQ_FILLED; 1066 init_completion(&sclp_request_queue_flushed); 1067 1068 rc = sclp_add_request(&sclp_suspend_req); 1069 if (rc == 0) 1070 wait_for_completion(&sclp_request_queue_flushed); 1071 else if (rc != -ENODATA) 1072 goto fail_thaw; 1073 1074 rc = sclp_deactivate(); 1075 if (rc) 1076 goto fail_thaw; 1077 return 0; 1078 1079 fail_thaw: 1080 spin_lock_irqsave(&sclp_lock, flags); 1081 sclp_suspend_state = sclp_suspend_state_running; 1082 spin_unlock_irqrestore(&sclp_lock, flags); 1083 sclp_pm_event(SCLP_PM_EVENT_THAW, 1); 1084 return rc; 1085 } 1086 1087 static int sclp_undo_suspend(enum sclp_pm_event event) 1088 { 1089 unsigned long flags; 1090 int rc; 1091 1092 rc = sclp_reactivate(); 1093 if (rc) 1094 return rc; 1095 1096 spin_lock_irqsave(&sclp_lock, flags); 1097 sclp_suspend_state = sclp_suspend_state_running; 1098 spin_unlock_irqrestore(&sclp_lock, flags); 1099 1100 sclp_pm_event(event, 0); 1101 return 0; 1102 } 1103 1104 static int sclp_thaw(struct device *dev) 1105 { 1106 return sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1107 } 1108 1109 static int sclp_restore(struct device *dev) 1110 { 1111 return sclp_undo_suspend(SCLP_PM_EVENT_RESTORE); 1112 } 1113 1114 static const struct dev_pm_ops sclp_pm_ops = { 1115 .freeze = sclp_freeze, 1116 .thaw = sclp_thaw, 1117 .restore = sclp_restore, 1118 }; 1119 1120 static ssize_t con_pages_show(struct device_driver *dev, char *buf) 1121 { 1122 return sprintf(buf, "%i\n", sclp_console_pages); 1123 } 1124 1125 static DRIVER_ATTR_RO(con_pages); 1126 1127 static ssize_t con_drop_show(struct device_driver *dev, char *buf) 1128 { 1129 return sprintf(buf, "%i\n", sclp_console_drop); 1130 } 1131 1132 static DRIVER_ATTR_RO(con_drop); 1133 1134 static ssize_t con_full_show(struct device_driver *dev, char *buf) 1135 { 1136 return sprintf(buf, "%lu\n", sclp_console_full); 1137 } 1138 1139 static DRIVER_ATTR_RO(con_full); 1140 1141 static struct attribute *sclp_drv_attrs[] = { 1142 &driver_attr_con_pages.attr, 1143 &driver_attr_con_drop.attr, 1144 &driver_attr_con_full.attr, 1145 NULL, 1146 }; 1147 static struct attribute_group sclp_drv_attr_group = { 1148 .attrs = sclp_drv_attrs, 1149 }; 1150 static const struct attribute_group *sclp_drv_attr_groups[] = { 1151 &sclp_drv_attr_group, 1152 NULL, 1153 }; 1154 1155 static struct platform_driver sclp_pdrv = { 1156 .driver = { 1157 .name = "sclp", 1158 .pm = &sclp_pm_ops, 1159 .groups = sclp_drv_attr_groups, 1160 }, 1161 }; 1162 1163 static struct platform_device *sclp_pdev; 1164 1165 /* Initialize SCLP driver. Return zero if driver is operational, non-zero 1166 * otherwise. */ 1167 static int 1168 sclp_init(void) 1169 { 1170 unsigned long flags; 1171 int rc = 0; 1172 1173 spin_lock_irqsave(&sclp_lock, flags); 1174 /* Check for previous or running initialization */ 1175 if (sclp_init_state != sclp_init_state_uninitialized) 1176 goto fail_unlock; 1177 sclp_init_state = sclp_init_state_initializing; 1178 sclp_read_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA); 1179 sclp_init_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA); 1180 BUG_ON(!sclp_read_sccb || !sclp_init_sccb); 1181 /* Set up variables */ 1182 list_add(&sclp_state_change_event.list, &sclp_reg_list); 1183 timer_setup(&sclp_request_timer, NULL, 0); 1184 timer_setup(&sclp_queue_timer, sclp_req_queue_timeout, 0); 1185 /* Check interface */ 1186 spin_unlock_irqrestore(&sclp_lock, flags); 1187 rc = sclp_check_interface(); 1188 spin_lock_irqsave(&sclp_lock, flags); 1189 if (rc) 1190 goto fail_init_state_uninitialized; 1191 /* Register reboot handler */ 1192 rc = register_reboot_notifier(&sclp_reboot_notifier); 1193 if (rc) 1194 goto fail_init_state_uninitialized; 1195 /* Register interrupt handler */ 1196 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler); 1197 if (rc) 1198 goto fail_unregister_reboot_notifier; 1199 sclp_init_state = sclp_init_state_initialized; 1200 spin_unlock_irqrestore(&sclp_lock, flags); 1201 /* Enable service-signal external interruption - needs to happen with 1202 * IRQs enabled. */ 1203 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 1204 sclp_init_mask(1); 1205 return 0; 1206 1207 fail_unregister_reboot_notifier: 1208 unregister_reboot_notifier(&sclp_reboot_notifier); 1209 fail_init_state_uninitialized: 1210 sclp_init_state = sclp_init_state_uninitialized; 1211 free_page((unsigned long) sclp_read_sccb); 1212 free_page((unsigned long) sclp_init_sccb); 1213 fail_unlock: 1214 spin_unlock_irqrestore(&sclp_lock, flags); 1215 return rc; 1216 } 1217 1218 /* 1219 * SCLP panic notifier: If we are suspended, we thaw SCLP in order to be able 1220 * to print the panic message. 1221 */ 1222 static int sclp_panic_notify(struct notifier_block *self, 1223 unsigned long event, void *data) 1224 { 1225 if (sclp_suspend_state == sclp_suspend_state_suspended) 1226 sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1227 return NOTIFY_OK; 1228 } 1229 1230 static struct notifier_block sclp_on_panic_nb = { 1231 .notifier_call = sclp_panic_notify, 1232 .priority = SCLP_PANIC_PRIO, 1233 }; 1234 1235 static __init int sclp_initcall(void) 1236 { 1237 int rc; 1238 1239 rc = platform_driver_register(&sclp_pdrv); 1240 if (rc) 1241 return rc; 1242 1243 sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0); 1244 rc = PTR_ERR_OR_ZERO(sclp_pdev); 1245 if (rc) 1246 goto fail_platform_driver_unregister; 1247 1248 rc = atomic_notifier_chain_register(&panic_notifier_list, 1249 &sclp_on_panic_nb); 1250 if (rc) 1251 goto fail_platform_device_unregister; 1252 1253 return sclp_init(); 1254 1255 fail_platform_device_unregister: 1256 platform_device_unregister(sclp_pdev); 1257 fail_platform_driver_unregister: 1258 platform_driver_unregister(&sclp_pdrv); 1259 return rc; 1260 } 1261 1262 arch_initcall(sclp_initcall); 1263