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