1 /* 2 * core function to access sclp interface 3 * 4 * Copyright IBM Corp. 1999, 2009 5 * 6 * Author(s): Martin Peschke <mpeschke@de.ibm.com> 7 * Martin Schwidefsky <schwidefsky@de.ibm.com> 8 */ 9 10 #include <linux/kernel_stat.h> 11 #include <linux/module.h> 12 #include <linux/err.h> 13 #include <linux/spinlock.h> 14 #include <linux/interrupt.h> 15 #include <linux/timer.h> 16 #include <linux/reboot.h> 17 #include <linux/jiffies.h> 18 #include <linux/init.h> 19 #include <linux/suspend.h> 20 #include <linux/completion.h> 21 #include <linux/platform_device.h> 22 #include <asm/types.h> 23 #include <asm/irq.h> 24 25 #include "sclp.h" 26 27 #define SCLP_HEADER "sclp: " 28 29 /* Lock to protect internal data consistency. */ 30 static DEFINE_SPINLOCK(sclp_lock); 31 32 /* Mask of events that we can send to the sclp interface. */ 33 static sccb_mask_t sclp_receive_mask; 34 35 /* Mask of events that we can receive from the sclp interface. */ 36 static sccb_mask_t sclp_send_mask; 37 38 /* List of registered event listeners and senders. */ 39 static struct list_head sclp_reg_list; 40 41 /* List of queued requests. */ 42 static struct list_head sclp_req_queue; 43 44 /* Data for read and and init requests. */ 45 static struct sclp_req sclp_read_req; 46 static struct sclp_req sclp_init_req; 47 static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 48 static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 49 50 /* Suspend request */ 51 static DECLARE_COMPLETION(sclp_request_queue_flushed); 52 53 /* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */ 54 int sclp_console_pages = SCLP_CONSOLE_PAGES; 55 /* Flag to indicate if buffer pages are dropped on buffer full condition */ 56 int sclp_console_drop = 1; 57 /* Number of times the console dropped buffer pages */ 58 unsigned long sclp_console_full; 59 60 static void sclp_suspend_req_cb(struct sclp_req *req, void *data) 61 { 62 complete(&sclp_request_queue_flushed); 63 } 64 65 static int __init sclp_setup_console_pages(char *str) 66 { 67 int pages, rc; 68 69 rc = kstrtoint(str, 0, &pages); 70 if (!rc && pages >= SCLP_CONSOLE_PAGES) 71 sclp_console_pages = pages; 72 return 1; 73 } 74 75 __setup("sclp_con_pages=", sclp_setup_console_pages); 76 77 static int __init sclp_setup_console_drop(char *str) 78 { 79 int drop, rc; 80 81 rc = kstrtoint(str, 0, &drop); 82 if (!rc) 83 sclp_console_drop = drop; 84 return 1; 85 } 86 87 __setup("sclp_con_drop=", sclp_setup_console_drop); 88 89 static struct sclp_req sclp_suspend_req; 90 91 /* Timer for request retries. */ 92 static struct timer_list sclp_request_timer; 93 94 /* Timer for queued requests. */ 95 static struct timer_list sclp_queue_timer; 96 97 /* Internal state: is the driver initialized? */ 98 static volatile enum sclp_init_state_t { 99 sclp_init_state_uninitialized, 100 sclp_init_state_initializing, 101 sclp_init_state_initialized 102 } sclp_init_state = sclp_init_state_uninitialized; 103 104 /* Internal state: is a request active at the sclp? */ 105 static volatile enum sclp_running_state_t { 106 sclp_running_state_idle, 107 sclp_running_state_running, 108 sclp_running_state_reset_pending 109 } sclp_running_state = sclp_running_state_idle; 110 111 /* Internal state: is a read request pending? */ 112 static volatile enum sclp_reading_state_t { 113 sclp_reading_state_idle, 114 sclp_reading_state_reading 115 } sclp_reading_state = sclp_reading_state_idle; 116 117 /* Internal state: is the driver currently serving requests? */ 118 static volatile enum sclp_activation_state_t { 119 sclp_activation_state_active, 120 sclp_activation_state_deactivating, 121 sclp_activation_state_inactive, 122 sclp_activation_state_activating 123 } sclp_activation_state = sclp_activation_state_active; 124 125 /* Internal state: is an init mask request pending? */ 126 static volatile enum sclp_mask_state_t { 127 sclp_mask_state_idle, 128 sclp_mask_state_initializing 129 } sclp_mask_state = sclp_mask_state_idle; 130 131 /* Internal state: is the driver suspended? */ 132 static enum sclp_suspend_state_t { 133 sclp_suspend_state_running, 134 sclp_suspend_state_suspended, 135 } sclp_suspend_state = sclp_suspend_state_running; 136 137 /* Maximum retry counts */ 138 #define SCLP_INIT_RETRY 3 139 #define SCLP_MASK_RETRY 3 140 141 /* Timeout intervals in seconds.*/ 142 #define SCLP_BUSY_INTERVAL 10 143 #define SCLP_RETRY_INTERVAL 30 144 145 static void sclp_process_queue(void); 146 static void __sclp_make_read_req(void); 147 static int sclp_init_mask(int calculate); 148 static int sclp_init(void); 149 150 /* Perform service call. Return 0 on success, non-zero otherwise. */ 151 int 152 sclp_service_call(sclp_cmdw_t command, void *sccb) 153 { 154 int cc = 4; /* Initialize for program check handling */ 155 156 asm volatile( 157 "0: .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 158 "1: ipm %0\n" 159 " srl %0,28\n" 160 "2:\n" 161 EX_TABLE(0b, 2b) 162 EX_TABLE(1b, 2b) 163 : "+&d" (cc) : "d" (command), "a" (__pa(sccb)) 164 : "cc", "memory"); 165 if (cc == 4) 166 return -EINVAL; 167 if (cc == 3) 168 return -EIO; 169 if (cc == 2) 170 return -EBUSY; 171 return 0; 172 } 173 174 175 static void 176 __sclp_queue_read_req(void) 177 { 178 if (sclp_reading_state == sclp_reading_state_idle) { 179 sclp_reading_state = sclp_reading_state_reading; 180 __sclp_make_read_req(); 181 /* Add request to head of queue */ 182 list_add(&sclp_read_req.list, &sclp_req_queue); 183 } 184 } 185 186 /* Set up request retry timer. Called while sclp_lock is locked. */ 187 static inline void 188 __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), 189 unsigned long data) 190 { 191 del_timer(&sclp_request_timer); 192 sclp_request_timer.function = function; 193 sclp_request_timer.data = data; 194 sclp_request_timer.expires = jiffies + time; 195 add_timer(&sclp_request_timer); 196 } 197 198 /* Request timeout handler. Restart the request queue. If DATA is non-zero, 199 * force restart of running request. */ 200 static void 201 sclp_request_timeout(unsigned long data) 202 { 203 unsigned long flags; 204 205 spin_lock_irqsave(&sclp_lock, flags); 206 if (data) { 207 if (sclp_running_state == sclp_running_state_running) { 208 /* Break running state and queue NOP read event request 209 * to get a defined interface state. */ 210 __sclp_queue_read_req(); 211 sclp_running_state = sclp_running_state_idle; 212 } 213 } else { 214 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 215 sclp_request_timeout, 0); 216 } 217 spin_unlock_irqrestore(&sclp_lock, flags); 218 sclp_process_queue(); 219 } 220 221 /* 222 * Returns the expire value in jiffies of the next pending request timeout, 223 * if any. Needs to be called with sclp_lock. 224 */ 225 static unsigned long __sclp_req_queue_find_next_timeout(void) 226 { 227 unsigned long expires_next = 0; 228 struct sclp_req *req; 229 230 list_for_each_entry(req, &sclp_req_queue, list) { 231 if (!req->queue_expires) 232 continue; 233 if (!expires_next || 234 (time_before(req->queue_expires, expires_next))) 235 expires_next = req->queue_expires; 236 } 237 return expires_next; 238 } 239 240 /* 241 * Returns expired request, if any, and removes it from the list. 242 */ 243 static struct sclp_req *__sclp_req_queue_remove_expired_req(void) 244 { 245 unsigned long flags, now; 246 struct sclp_req *req; 247 248 spin_lock_irqsave(&sclp_lock, flags); 249 now = jiffies; 250 /* Don't need list_for_each_safe because we break out after list_del */ 251 list_for_each_entry(req, &sclp_req_queue, list) { 252 if (!req->queue_expires) 253 continue; 254 if (time_before_eq(req->queue_expires, now)) { 255 if (req->status == SCLP_REQ_QUEUED) { 256 req->status = SCLP_REQ_QUEUED_TIMEOUT; 257 list_del(&req->list); 258 goto out; 259 } 260 } 261 } 262 req = NULL; 263 out: 264 spin_unlock_irqrestore(&sclp_lock, flags); 265 return req; 266 } 267 268 /* 269 * Timeout handler for queued requests. Removes request from list and 270 * invokes callback. This timer can be set per request in situations where 271 * waiting too long would be harmful to the system, e.g. during SE reboot. 272 */ 273 static void sclp_req_queue_timeout(unsigned long data) 274 { 275 unsigned long flags, expires_next; 276 struct sclp_req *req; 277 278 do { 279 req = __sclp_req_queue_remove_expired_req(); 280 if (req && req->callback) 281 req->callback(req, req->callback_data); 282 } while (req); 283 284 spin_lock_irqsave(&sclp_lock, flags); 285 expires_next = __sclp_req_queue_find_next_timeout(); 286 if (expires_next) 287 mod_timer(&sclp_queue_timer, expires_next); 288 spin_unlock_irqrestore(&sclp_lock, flags); 289 } 290 291 /* Try to start a request. Return zero if the request was successfully 292 * started or if it will be started at a later time. Return non-zero otherwise. 293 * Called while sclp_lock is locked. */ 294 static int 295 __sclp_start_request(struct sclp_req *req) 296 { 297 int rc; 298 299 if (sclp_running_state != sclp_running_state_idle) 300 return 0; 301 del_timer(&sclp_request_timer); 302 rc = sclp_service_call(req->command, req->sccb); 303 req->start_count++; 304 305 if (rc == 0) { 306 /* Successfully started request */ 307 req->status = SCLP_REQ_RUNNING; 308 sclp_running_state = sclp_running_state_running; 309 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 310 sclp_request_timeout, 1); 311 return 0; 312 } else if (rc == -EBUSY) { 313 /* Try again later */ 314 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 315 sclp_request_timeout, 0); 316 return 0; 317 } 318 /* Request failed */ 319 req->status = SCLP_REQ_FAILED; 320 return rc; 321 } 322 323 /* Try to start queued requests. */ 324 static void 325 sclp_process_queue(void) 326 { 327 struct sclp_req *req; 328 int rc; 329 unsigned long flags; 330 331 spin_lock_irqsave(&sclp_lock, flags); 332 if (sclp_running_state != sclp_running_state_idle) { 333 spin_unlock_irqrestore(&sclp_lock, flags); 334 return; 335 } 336 del_timer(&sclp_request_timer); 337 while (!list_empty(&sclp_req_queue)) { 338 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 339 if (!req->sccb) 340 goto do_post; 341 rc = __sclp_start_request(req); 342 if (rc == 0) 343 break; 344 /* Request failed */ 345 if (req->start_count > 1) { 346 /* Cannot abort already submitted request - could still 347 * be active at the SCLP */ 348 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 349 sclp_request_timeout, 0); 350 break; 351 } 352 do_post: 353 /* Post-processing for aborted request */ 354 list_del(&req->list); 355 if (req->callback) { 356 spin_unlock_irqrestore(&sclp_lock, flags); 357 req->callback(req, req->callback_data); 358 spin_lock_irqsave(&sclp_lock, flags); 359 } 360 } 361 spin_unlock_irqrestore(&sclp_lock, flags); 362 } 363 364 static int __sclp_can_add_request(struct sclp_req *req) 365 { 366 if (req == &sclp_suspend_req || req == &sclp_init_req) 367 return 1; 368 if (sclp_suspend_state != sclp_suspend_state_running) 369 return 0; 370 if (sclp_init_state != sclp_init_state_initialized) 371 return 0; 372 if (sclp_activation_state != sclp_activation_state_active) 373 return 0; 374 return 1; 375 } 376 377 /* Queue a new request. Return zero on success, non-zero otherwise. */ 378 int 379 sclp_add_request(struct sclp_req *req) 380 { 381 unsigned long flags; 382 int rc; 383 384 spin_lock_irqsave(&sclp_lock, flags); 385 if (!__sclp_can_add_request(req)) { 386 spin_unlock_irqrestore(&sclp_lock, flags); 387 return -EIO; 388 } 389 req->status = SCLP_REQ_QUEUED; 390 req->start_count = 0; 391 list_add_tail(&req->list, &sclp_req_queue); 392 rc = 0; 393 if (req->queue_timeout) { 394 req->queue_expires = jiffies + req->queue_timeout * HZ; 395 if (!timer_pending(&sclp_queue_timer) || 396 time_after(sclp_queue_timer.expires, req->queue_expires)) 397 mod_timer(&sclp_queue_timer, req->queue_expires); 398 } else 399 req->queue_expires = 0; 400 /* Start if request is first in list */ 401 if (sclp_running_state == sclp_running_state_idle && 402 req->list.prev == &sclp_req_queue) { 403 if (!req->sccb) { 404 list_del(&req->list); 405 rc = -ENODATA; 406 goto out; 407 } 408 rc = __sclp_start_request(req); 409 if (rc) 410 list_del(&req->list); 411 } 412 out: 413 spin_unlock_irqrestore(&sclp_lock, flags); 414 return rc; 415 } 416 417 EXPORT_SYMBOL(sclp_add_request); 418 419 /* Dispatch events found in request buffer to registered listeners. Return 0 420 * if all events were dispatched, non-zero otherwise. */ 421 static int 422 sclp_dispatch_evbufs(struct sccb_header *sccb) 423 { 424 unsigned long flags; 425 struct evbuf_header *evbuf; 426 struct list_head *l; 427 struct sclp_register *reg; 428 int offset; 429 int rc; 430 431 spin_lock_irqsave(&sclp_lock, flags); 432 rc = 0; 433 for (offset = sizeof(struct sccb_header); offset < sccb->length; 434 offset += evbuf->length) { 435 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 436 /* Check for malformed hardware response */ 437 if (evbuf->length == 0) 438 break; 439 /* Search for event handler */ 440 reg = NULL; 441 list_for_each(l, &sclp_reg_list) { 442 reg = list_entry(l, struct sclp_register, list); 443 if (reg->receive_mask & (1 << (32 - evbuf->type))) 444 break; 445 else 446 reg = NULL; 447 } 448 if (reg && reg->receiver_fn) { 449 spin_unlock_irqrestore(&sclp_lock, flags); 450 reg->receiver_fn(evbuf); 451 spin_lock_irqsave(&sclp_lock, flags); 452 } else if (reg == NULL) 453 rc = -EOPNOTSUPP; 454 } 455 spin_unlock_irqrestore(&sclp_lock, flags); 456 return rc; 457 } 458 459 /* Read event data request callback. */ 460 static void 461 sclp_read_cb(struct sclp_req *req, void *data) 462 { 463 unsigned long flags; 464 struct sccb_header *sccb; 465 466 sccb = (struct sccb_header *) req->sccb; 467 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 468 sccb->response_code == 0x220)) 469 sclp_dispatch_evbufs(sccb); 470 spin_lock_irqsave(&sclp_lock, flags); 471 sclp_reading_state = sclp_reading_state_idle; 472 spin_unlock_irqrestore(&sclp_lock, flags); 473 } 474 475 /* Prepare read event data request. Called while sclp_lock is locked. */ 476 static void __sclp_make_read_req(void) 477 { 478 struct sccb_header *sccb; 479 480 sccb = (struct sccb_header *) sclp_read_sccb; 481 clear_page(sccb); 482 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 483 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 484 sclp_read_req.status = SCLP_REQ_QUEUED; 485 sclp_read_req.start_count = 0; 486 sclp_read_req.callback = sclp_read_cb; 487 sclp_read_req.sccb = sccb; 488 sccb->length = PAGE_SIZE; 489 sccb->function_code = 0; 490 sccb->control_mask[2] = 0x80; 491 } 492 493 /* Search request list for request with matching sccb. Return request if found, 494 * NULL otherwise. Called while sclp_lock is locked. */ 495 static inline struct sclp_req * 496 __sclp_find_req(u32 sccb) 497 { 498 struct list_head *l; 499 struct sclp_req *req; 500 501 list_for_each(l, &sclp_req_queue) { 502 req = list_entry(l, struct sclp_req, list); 503 if (sccb == (u32) (addr_t) req->sccb) 504 return req; 505 } 506 return NULL; 507 } 508 509 /* Handler for external interruption. Perform request post-processing. 510 * Prepare read event data request if necessary. Start processing of next 511 * request on queue. */ 512 static void sclp_interrupt_handler(struct ext_code ext_code, 513 unsigned int param32, unsigned long param64) 514 { 515 struct sclp_req *req; 516 u32 finished_sccb; 517 u32 evbuf_pending; 518 519 inc_irq_stat(IRQEXT_SCP); 520 spin_lock(&sclp_lock); 521 finished_sccb = param32 & 0xfffffff8; 522 evbuf_pending = param32 & 0x3; 523 if (finished_sccb) { 524 del_timer(&sclp_request_timer); 525 sclp_running_state = sclp_running_state_reset_pending; 526 req = __sclp_find_req(finished_sccb); 527 if (req) { 528 /* Request post-processing */ 529 list_del(&req->list); 530 req->status = SCLP_REQ_DONE; 531 if (req->callback) { 532 spin_unlock(&sclp_lock); 533 req->callback(req, req->callback_data); 534 spin_lock(&sclp_lock); 535 } 536 } 537 sclp_running_state = sclp_running_state_idle; 538 } 539 if (evbuf_pending && 540 sclp_activation_state == sclp_activation_state_active) 541 __sclp_queue_read_req(); 542 spin_unlock(&sclp_lock); 543 sclp_process_queue(); 544 } 545 546 /* Convert interval in jiffies to TOD ticks. */ 547 static inline u64 548 sclp_tod_from_jiffies(unsigned long jiffies) 549 { 550 return (u64) (jiffies / HZ) << 32; 551 } 552 553 /* Wait until a currently running request finished. Note: while this function 554 * is running, no timers are served on the calling CPU. */ 555 void 556 sclp_sync_wait(void) 557 { 558 unsigned long long old_tick; 559 unsigned long flags; 560 unsigned long cr0, cr0_sync; 561 u64 timeout; 562 int irq_context; 563 564 /* We'll be disabling timer interrupts, so we need a custom timeout 565 * mechanism */ 566 timeout = 0; 567 if (timer_pending(&sclp_request_timer)) { 568 /* Get timeout TOD value */ 569 timeout = get_tod_clock_fast() + 570 sclp_tod_from_jiffies(sclp_request_timer.expires - 571 jiffies); 572 } 573 local_irq_save(flags); 574 /* Prevent bottom half from executing once we force interrupts open */ 575 irq_context = in_interrupt(); 576 if (!irq_context) 577 local_bh_disable(); 578 /* Enable service-signal interruption, disable timer interrupts */ 579 old_tick = local_tick_disable(); 580 trace_hardirqs_on(); 581 __ctl_store(cr0, 0, 0); 582 cr0_sync = cr0 & ~CR0_IRQ_SUBCLASS_MASK; 583 cr0_sync |= 1UL << (63 - 54); 584 __ctl_load(cr0_sync, 0, 0); 585 __arch_local_irq_stosm(0x01); 586 /* Loop until driver state indicates finished request */ 587 while (sclp_running_state != sclp_running_state_idle) { 588 /* Check for expired request timer */ 589 if (timer_pending(&sclp_request_timer) && 590 get_tod_clock_fast() > timeout && 591 del_timer(&sclp_request_timer)) 592 sclp_request_timer.function(sclp_request_timer.data); 593 cpu_relax(); 594 } 595 local_irq_disable(); 596 __ctl_load(cr0, 0, 0); 597 if (!irq_context) 598 _local_bh_enable(); 599 local_tick_enable(old_tick); 600 local_irq_restore(flags); 601 } 602 EXPORT_SYMBOL(sclp_sync_wait); 603 604 /* Dispatch changes in send and receive mask to registered listeners. */ 605 static void 606 sclp_dispatch_state_change(void) 607 { 608 struct list_head *l; 609 struct sclp_register *reg; 610 unsigned long flags; 611 sccb_mask_t receive_mask; 612 sccb_mask_t send_mask; 613 614 do { 615 spin_lock_irqsave(&sclp_lock, flags); 616 reg = NULL; 617 list_for_each(l, &sclp_reg_list) { 618 reg = list_entry(l, struct sclp_register, list); 619 receive_mask = reg->send_mask & sclp_receive_mask; 620 send_mask = reg->receive_mask & sclp_send_mask; 621 if (reg->sclp_receive_mask != receive_mask || 622 reg->sclp_send_mask != send_mask) { 623 reg->sclp_receive_mask = receive_mask; 624 reg->sclp_send_mask = send_mask; 625 break; 626 } else 627 reg = NULL; 628 } 629 spin_unlock_irqrestore(&sclp_lock, flags); 630 if (reg && reg->state_change_fn) 631 reg->state_change_fn(reg); 632 } while (reg); 633 } 634 635 struct sclp_statechangebuf { 636 struct evbuf_header header; 637 u8 validity_sclp_active_facility_mask : 1; 638 u8 validity_sclp_receive_mask : 1; 639 u8 validity_sclp_send_mask : 1; 640 u8 validity_read_data_function_mask : 1; 641 u16 _zeros : 12; 642 u16 mask_length; 643 u64 sclp_active_facility_mask; 644 sccb_mask_t sclp_receive_mask; 645 sccb_mask_t sclp_send_mask; 646 u32 read_data_function_mask; 647 } __attribute__((packed)); 648 649 650 /* State change event callback. Inform listeners of changes. */ 651 static void 652 sclp_state_change_cb(struct evbuf_header *evbuf) 653 { 654 unsigned long flags; 655 struct sclp_statechangebuf *scbuf; 656 657 scbuf = (struct sclp_statechangebuf *) evbuf; 658 if (scbuf->mask_length != sizeof(sccb_mask_t)) 659 return; 660 spin_lock_irqsave(&sclp_lock, flags); 661 if (scbuf->validity_sclp_receive_mask) 662 sclp_receive_mask = scbuf->sclp_receive_mask; 663 if (scbuf->validity_sclp_send_mask) 664 sclp_send_mask = scbuf->sclp_send_mask; 665 spin_unlock_irqrestore(&sclp_lock, flags); 666 if (scbuf->validity_sclp_active_facility_mask) 667 sclp.facilities = scbuf->sclp_active_facility_mask; 668 sclp_dispatch_state_change(); 669 } 670 671 static struct sclp_register sclp_state_change_event = { 672 .receive_mask = EVTYP_STATECHANGE_MASK, 673 .receiver_fn = sclp_state_change_cb 674 }; 675 676 /* Calculate receive and send mask of currently registered listeners. 677 * Called while sclp_lock is locked. */ 678 static inline void 679 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 680 { 681 struct list_head *l; 682 struct sclp_register *t; 683 684 *receive_mask = 0; 685 *send_mask = 0; 686 list_for_each(l, &sclp_reg_list) { 687 t = list_entry(l, struct sclp_register, list); 688 *receive_mask |= t->receive_mask; 689 *send_mask |= t->send_mask; 690 } 691 } 692 693 /* Register event listener. Return 0 on success, non-zero otherwise. */ 694 int 695 sclp_register(struct sclp_register *reg) 696 { 697 unsigned long flags; 698 sccb_mask_t receive_mask; 699 sccb_mask_t send_mask; 700 int rc; 701 702 rc = sclp_init(); 703 if (rc) 704 return rc; 705 spin_lock_irqsave(&sclp_lock, flags); 706 /* Check event mask for collisions */ 707 __sclp_get_mask(&receive_mask, &send_mask); 708 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 709 spin_unlock_irqrestore(&sclp_lock, flags); 710 return -EBUSY; 711 } 712 /* Trigger initial state change callback */ 713 reg->sclp_receive_mask = 0; 714 reg->sclp_send_mask = 0; 715 reg->pm_event_posted = 0; 716 list_add(®->list, &sclp_reg_list); 717 spin_unlock_irqrestore(&sclp_lock, flags); 718 rc = sclp_init_mask(1); 719 if (rc) { 720 spin_lock_irqsave(&sclp_lock, flags); 721 list_del(®->list); 722 spin_unlock_irqrestore(&sclp_lock, flags); 723 } 724 return rc; 725 } 726 727 EXPORT_SYMBOL(sclp_register); 728 729 /* Unregister event listener. */ 730 void 731 sclp_unregister(struct sclp_register *reg) 732 { 733 unsigned long flags; 734 735 spin_lock_irqsave(&sclp_lock, flags); 736 list_del(®->list); 737 spin_unlock_irqrestore(&sclp_lock, flags); 738 sclp_init_mask(1); 739 } 740 741 EXPORT_SYMBOL(sclp_unregister); 742 743 /* Remove event buffers which are marked processed. Return the number of 744 * remaining event buffers. */ 745 int 746 sclp_remove_processed(struct sccb_header *sccb) 747 { 748 struct evbuf_header *evbuf; 749 int unprocessed; 750 u16 remaining; 751 752 evbuf = (struct evbuf_header *) (sccb + 1); 753 unprocessed = 0; 754 remaining = sccb->length - sizeof(struct sccb_header); 755 while (remaining > 0) { 756 remaining -= evbuf->length; 757 if (evbuf->flags & 0x80) { 758 sccb->length -= evbuf->length; 759 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 760 remaining); 761 } else { 762 unprocessed++; 763 evbuf = (struct evbuf_header *) 764 ((addr_t) evbuf + evbuf->length); 765 } 766 } 767 return unprocessed; 768 } 769 770 EXPORT_SYMBOL(sclp_remove_processed); 771 772 /* Prepare init mask request. Called while sclp_lock is locked. */ 773 static inline void 774 __sclp_make_init_req(u32 receive_mask, u32 send_mask) 775 { 776 struct init_sccb *sccb; 777 778 sccb = (struct init_sccb *) sclp_init_sccb; 779 clear_page(sccb); 780 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 781 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 782 sclp_init_req.status = SCLP_REQ_FILLED; 783 sclp_init_req.start_count = 0; 784 sclp_init_req.callback = NULL; 785 sclp_init_req.callback_data = NULL; 786 sclp_init_req.sccb = sccb; 787 sccb->header.length = sizeof(struct init_sccb); 788 sccb->mask_length = sizeof(sccb_mask_t); 789 sccb->receive_mask = receive_mask; 790 sccb->send_mask = send_mask; 791 sccb->sclp_receive_mask = 0; 792 sccb->sclp_send_mask = 0; 793 } 794 795 /* Start init mask request. If calculate is non-zero, calculate the mask as 796 * requested by registered listeners. Use zero mask otherwise. Return 0 on 797 * success, non-zero otherwise. */ 798 static int 799 sclp_init_mask(int calculate) 800 { 801 unsigned long flags; 802 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 803 sccb_mask_t receive_mask; 804 sccb_mask_t send_mask; 805 int retry; 806 int rc; 807 unsigned long wait; 808 809 spin_lock_irqsave(&sclp_lock, flags); 810 /* Check if interface is in appropriate state */ 811 if (sclp_mask_state != sclp_mask_state_idle) { 812 spin_unlock_irqrestore(&sclp_lock, flags); 813 return -EBUSY; 814 } 815 if (sclp_activation_state == sclp_activation_state_inactive) { 816 spin_unlock_irqrestore(&sclp_lock, flags); 817 return -EINVAL; 818 } 819 sclp_mask_state = sclp_mask_state_initializing; 820 /* Determine mask */ 821 if (calculate) 822 __sclp_get_mask(&receive_mask, &send_mask); 823 else { 824 receive_mask = 0; 825 send_mask = 0; 826 } 827 rc = -EIO; 828 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 829 /* Prepare request */ 830 __sclp_make_init_req(receive_mask, send_mask); 831 spin_unlock_irqrestore(&sclp_lock, flags); 832 if (sclp_add_request(&sclp_init_req)) { 833 /* Try again later */ 834 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 835 while (time_before(jiffies, wait)) 836 sclp_sync_wait(); 837 spin_lock_irqsave(&sclp_lock, flags); 838 continue; 839 } 840 while (sclp_init_req.status != SCLP_REQ_DONE && 841 sclp_init_req.status != SCLP_REQ_FAILED) 842 sclp_sync_wait(); 843 spin_lock_irqsave(&sclp_lock, flags); 844 if (sclp_init_req.status == SCLP_REQ_DONE && 845 sccb->header.response_code == 0x20) { 846 /* Successful request */ 847 if (calculate) { 848 sclp_receive_mask = sccb->sclp_receive_mask; 849 sclp_send_mask = sccb->sclp_send_mask; 850 } else { 851 sclp_receive_mask = 0; 852 sclp_send_mask = 0; 853 } 854 spin_unlock_irqrestore(&sclp_lock, flags); 855 sclp_dispatch_state_change(); 856 spin_lock_irqsave(&sclp_lock, flags); 857 rc = 0; 858 break; 859 } 860 } 861 sclp_mask_state = sclp_mask_state_idle; 862 spin_unlock_irqrestore(&sclp_lock, flags); 863 return rc; 864 } 865 866 /* Deactivate SCLP interface. On success, new requests will be rejected, 867 * events will no longer be dispatched. Return 0 on success, non-zero 868 * otherwise. */ 869 int 870 sclp_deactivate(void) 871 { 872 unsigned long flags; 873 int rc; 874 875 spin_lock_irqsave(&sclp_lock, flags); 876 /* Deactivate can only be called when active */ 877 if (sclp_activation_state != sclp_activation_state_active) { 878 spin_unlock_irqrestore(&sclp_lock, flags); 879 return -EINVAL; 880 } 881 sclp_activation_state = sclp_activation_state_deactivating; 882 spin_unlock_irqrestore(&sclp_lock, flags); 883 rc = sclp_init_mask(0); 884 spin_lock_irqsave(&sclp_lock, flags); 885 if (rc == 0) 886 sclp_activation_state = sclp_activation_state_inactive; 887 else 888 sclp_activation_state = sclp_activation_state_active; 889 spin_unlock_irqrestore(&sclp_lock, flags); 890 return rc; 891 } 892 893 EXPORT_SYMBOL(sclp_deactivate); 894 895 /* Reactivate SCLP interface after sclp_deactivate. On success, new 896 * requests will be accepted, events will be dispatched again. Return 0 on 897 * success, non-zero otherwise. */ 898 int 899 sclp_reactivate(void) 900 { 901 unsigned long flags; 902 int rc; 903 904 spin_lock_irqsave(&sclp_lock, flags); 905 /* Reactivate can only be called when inactive */ 906 if (sclp_activation_state != sclp_activation_state_inactive) { 907 spin_unlock_irqrestore(&sclp_lock, flags); 908 return -EINVAL; 909 } 910 sclp_activation_state = sclp_activation_state_activating; 911 spin_unlock_irqrestore(&sclp_lock, flags); 912 rc = sclp_init_mask(1); 913 spin_lock_irqsave(&sclp_lock, flags); 914 if (rc == 0) 915 sclp_activation_state = sclp_activation_state_active; 916 else 917 sclp_activation_state = sclp_activation_state_inactive; 918 spin_unlock_irqrestore(&sclp_lock, flags); 919 return rc; 920 } 921 922 EXPORT_SYMBOL(sclp_reactivate); 923 924 /* Handler for external interruption used during initialization. Modify 925 * request state to done. */ 926 static void sclp_check_handler(struct ext_code ext_code, 927 unsigned int param32, unsigned long param64) 928 { 929 u32 finished_sccb; 930 931 inc_irq_stat(IRQEXT_SCP); 932 finished_sccb = param32 & 0xfffffff8; 933 /* Is this the interrupt we are waiting for? */ 934 if (finished_sccb == 0) 935 return; 936 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) 937 panic("sclp: unsolicited interrupt for buffer at 0x%x\n", 938 finished_sccb); 939 spin_lock(&sclp_lock); 940 if (sclp_running_state == sclp_running_state_running) { 941 sclp_init_req.status = SCLP_REQ_DONE; 942 sclp_running_state = sclp_running_state_idle; 943 } 944 spin_unlock(&sclp_lock); 945 } 946 947 /* Initial init mask request timed out. Modify request state to failed. */ 948 static void 949 sclp_check_timeout(unsigned long data) 950 { 951 unsigned long flags; 952 953 spin_lock_irqsave(&sclp_lock, flags); 954 if (sclp_running_state == sclp_running_state_running) { 955 sclp_init_req.status = SCLP_REQ_FAILED; 956 sclp_running_state = sclp_running_state_idle; 957 } 958 spin_unlock_irqrestore(&sclp_lock, flags); 959 } 960 961 /* Perform a check of the SCLP interface. Return zero if the interface is 962 * available and there are no pending requests from a previous instance. 963 * Return non-zero otherwise. */ 964 static int 965 sclp_check_interface(void) 966 { 967 struct init_sccb *sccb; 968 unsigned long flags; 969 int retry; 970 int rc; 971 972 spin_lock_irqsave(&sclp_lock, flags); 973 /* Prepare init mask command */ 974 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); 975 if (rc) { 976 spin_unlock_irqrestore(&sclp_lock, flags); 977 return rc; 978 } 979 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 980 __sclp_make_init_req(0, 0); 981 sccb = (struct init_sccb *) sclp_init_req.sccb; 982 rc = sclp_service_call(sclp_init_req.command, sccb); 983 if (rc == -EIO) 984 break; 985 sclp_init_req.status = SCLP_REQ_RUNNING; 986 sclp_running_state = sclp_running_state_running; 987 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 988 sclp_check_timeout, 0); 989 spin_unlock_irqrestore(&sclp_lock, flags); 990 /* Enable service-signal interruption - needs to happen 991 * with IRQs enabled. */ 992 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 993 /* Wait for signal from interrupt or timeout */ 994 sclp_sync_wait(); 995 /* Disable service-signal interruption - needs to happen 996 * with IRQs enabled. */ 997 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); 998 spin_lock_irqsave(&sclp_lock, flags); 999 del_timer(&sclp_request_timer); 1000 if (sclp_init_req.status == SCLP_REQ_DONE && 1001 sccb->header.response_code == 0x20) { 1002 rc = 0; 1003 break; 1004 } else 1005 rc = -EBUSY; 1006 } 1007 unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); 1008 spin_unlock_irqrestore(&sclp_lock, flags); 1009 return rc; 1010 } 1011 1012 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP 1013 * events from interfering with rebooted system. */ 1014 static int 1015 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 1016 { 1017 sclp_deactivate(); 1018 return NOTIFY_DONE; 1019 } 1020 1021 static struct notifier_block sclp_reboot_notifier = { 1022 .notifier_call = sclp_reboot_event 1023 }; 1024 1025 /* 1026 * Suspend/resume SCLP notifier implementation 1027 */ 1028 1029 static void sclp_pm_event(enum sclp_pm_event sclp_pm_event, int rollback) 1030 { 1031 struct sclp_register *reg; 1032 unsigned long flags; 1033 1034 if (!rollback) { 1035 spin_lock_irqsave(&sclp_lock, flags); 1036 list_for_each_entry(reg, &sclp_reg_list, list) 1037 reg->pm_event_posted = 0; 1038 spin_unlock_irqrestore(&sclp_lock, flags); 1039 } 1040 do { 1041 spin_lock_irqsave(&sclp_lock, flags); 1042 list_for_each_entry(reg, &sclp_reg_list, list) { 1043 if (rollback && reg->pm_event_posted) 1044 goto found; 1045 if (!rollback && !reg->pm_event_posted) 1046 goto found; 1047 } 1048 spin_unlock_irqrestore(&sclp_lock, flags); 1049 return; 1050 found: 1051 spin_unlock_irqrestore(&sclp_lock, flags); 1052 if (reg->pm_event_fn) 1053 reg->pm_event_fn(reg, sclp_pm_event); 1054 reg->pm_event_posted = rollback ? 0 : 1; 1055 } while (1); 1056 } 1057 1058 /* 1059 * Susend/resume callbacks for platform device 1060 */ 1061 1062 static int sclp_freeze(struct device *dev) 1063 { 1064 unsigned long flags; 1065 int rc; 1066 1067 sclp_pm_event(SCLP_PM_EVENT_FREEZE, 0); 1068 1069 spin_lock_irqsave(&sclp_lock, flags); 1070 sclp_suspend_state = sclp_suspend_state_suspended; 1071 spin_unlock_irqrestore(&sclp_lock, flags); 1072 1073 /* Init supend data */ 1074 memset(&sclp_suspend_req, 0, sizeof(sclp_suspend_req)); 1075 sclp_suspend_req.callback = sclp_suspend_req_cb; 1076 sclp_suspend_req.status = SCLP_REQ_FILLED; 1077 init_completion(&sclp_request_queue_flushed); 1078 1079 rc = sclp_add_request(&sclp_suspend_req); 1080 if (rc == 0) 1081 wait_for_completion(&sclp_request_queue_flushed); 1082 else if (rc != -ENODATA) 1083 goto fail_thaw; 1084 1085 rc = sclp_deactivate(); 1086 if (rc) 1087 goto fail_thaw; 1088 return 0; 1089 1090 fail_thaw: 1091 spin_lock_irqsave(&sclp_lock, flags); 1092 sclp_suspend_state = sclp_suspend_state_running; 1093 spin_unlock_irqrestore(&sclp_lock, flags); 1094 sclp_pm_event(SCLP_PM_EVENT_THAW, 1); 1095 return rc; 1096 } 1097 1098 static int sclp_undo_suspend(enum sclp_pm_event event) 1099 { 1100 unsigned long flags; 1101 int rc; 1102 1103 rc = sclp_reactivate(); 1104 if (rc) 1105 return rc; 1106 1107 spin_lock_irqsave(&sclp_lock, flags); 1108 sclp_suspend_state = sclp_suspend_state_running; 1109 spin_unlock_irqrestore(&sclp_lock, flags); 1110 1111 sclp_pm_event(event, 0); 1112 return 0; 1113 } 1114 1115 static int sclp_thaw(struct device *dev) 1116 { 1117 return sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1118 } 1119 1120 static int sclp_restore(struct device *dev) 1121 { 1122 return sclp_undo_suspend(SCLP_PM_EVENT_RESTORE); 1123 } 1124 1125 static const struct dev_pm_ops sclp_pm_ops = { 1126 .freeze = sclp_freeze, 1127 .thaw = sclp_thaw, 1128 .restore = sclp_restore, 1129 }; 1130 1131 static ssize_t sclp_show_console_pages(struct device_driver *dev, char *buf) 1132 { 1133 return sprintf(buf, "%i\n", sclp_console_pages); 1134 } 1135 1136 static DRIVER_ATTR(con_pages, S_IRUSR, sclp_show_console_pages, NULL); 1137 1138 static ssize_t sclp_show_con_drop(struct device_driver *dev, char *buf) 1139 { 1140 return sprintf(buf, "%i\n", sclp_console_drop); 1141 } 1142 1143 static DRIVER_ATTR(con_drop, S_IRUSR, sclp_show_con_drop, NULL); 1144 1145 static ssize_t sclp_show_console_full(struct device_driver *dev, char *buf) 1146 { 1147 return sprintf(buf, "%lu\n", sclp_console_full); 1148 } 1149 1150 static DRIVER_ATTR(con_full, S_IRUSR, sclp_show_console_full, NULL); 1151 1152 static struct attribute *sclp_drv_attrs[] = { 1153 &driver_attr_con_pages.attr, 1154 &driver_attr_con_drop.attr, 1155 &driver_attr_con_full.attr, 1156 NULL, 1157 }; 1158 static struct attribute_group sclp_drv_attr_group = { 1159 .attrs = sclp_drv_attrs, 1160 }; 1161 static const struct attribute_group *sclp_drv_attr_groups[] = { 1162 &sclp_drv_attr_group, 1163 NULL, 1164 }; 1165 1166 static struct platform_driver sclp_pdrv = { 1167 .driver = { 1168 .name = "sclp", 1169 .pm = &sclp_pm_ops, 1170 .groups = sclp_drv_attr_groups, 1171 }, 1172 }; 1173 1174 static struct platform_device *sclp_pdev; 1175 1176 /* Initialize SCLP driver. Return zero if driver is operational, non-zero 1177 * otherwise. */ 1178 static int 1179 sclp_init(void) 1180 { 1181 unsigned long flags; 1182 int rc = 0; 1183 1184 spin_lock_irqsave(&sclp_lock, flags); 1185 /* Check for previous or running initialization */ 1186 if (sclp_init_state != sclp_init_state_uninitialized) 1187 goto fail_unlock; 1188 sclp_init_state = sclp_init_state_initializing; 1189 /* Set up variables */ 1190 INIT_LIST_HEAD(&sclp_req_queue); 1191 INIT_LIST_HEAD(&sclp_reg_list); 1192 list_add(&sclp_state_change_event.list, &sclp_reg_list); 1193 init_timer(&sclp_request_timer); 1194 init_timer(&sclp_queue_timer); 1195 sclp_queue_timer.function = sclp_req_queue_timeout; 1196 /* Check interface */ 1197 spin_unlock_irqrestore(&sclp_lock, flags); 1198 rc = sclp_check_interface(); 1199 spin_lock_irqsave(&sclp_lock, flags); 1200 if (rc) 1201 goto fail_init_state_uninitialized; 1202 /* Register reboot handler */ 1203 rc = register_reboot_notifier(&sclp_reboot_notifier); 1204 if (rc) 1205 goto fail_init_state_uninitialized; 1206 /* Register interrupt handler */ 1207 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler); 1208 if (rc) 1209 goto fail_unregister_reboot_notifier; 1210 sclp_init_state = sclp_init_state_initialized; 1211 spin_unlock_irqrestore(&sclp_lock, flags); 1212 /* Enable service-signal external interruption - needs to happen with 1213 * IRQs enabled. */ 1214 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 1215 sclp_init_mask(1); 1216 return 0; 1217 1218 fail_unregister_reboot_notifier: 1219 unregister_reboot_notifier(&sclp_reboot_notifier); 1220 fail_init_state_uninitialized: 1221 sclp_init_state = sclp_init_state_uninitialized; 1222 fail_unlock: 1223 spin_unlock_irqrestore(&sclp_lock, flags); 1224 return rc; 1225 } 1226 1227 /* 1228 * SCLP panic notifier: If we are suspended, we thaw SCLP in order to be able 1229 * to print the panic message. 1230 */ 1231 static int sclp_panic_notify(struct notifier_block *self, 1232 unsigned long event, void *data) 1233 { 1234 if (sclp_suspend_state == sclp_suspend_state_suspended) 1235 sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1236 return NOTIFY_OK; 1237 } 1238 1239 static struct notifier_block sclp_on_panic_nb = { 1240 .notifier_call = sclp_panic_notify, 1241 .priority = SCLP_PANIC_PRIO, 1242 }; 1243 1244 static __init int sclp_initcall(void) 1245 { 1246 int rc; 1247 1248 rc = platform_driver_register(&sclp_pdrv); 1249 if (rc) 1250 return rc; 1251 1252 sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0); 1253 rc = PTR_ERR_OR_ZERO(sclp_pdev); 1254 if (rc) 1255 goto fail_platform_driver_unregister; 1256 1257 rc = atomic_notifier_chain_register(&panic_notifier_list, 1258 &sclp_on_panic_nb); 1259 if (rc) 1260 goto fail_platform_device_unregister; 1261 1262 return sclp_init(); 1263 1264 fail_platform_device_unregister: 1265 platform_device_unregister(sclp_pdev); 1266 fail_platform_driver_unregister: 1267 platform_driver_unregister(&sclp_pdrv); 1268 return rc; 1269 } 1270 1271 arch_initcall(sclp_initcall); 1272