1 /* 2 * drivers/s390/char/sclp.c 3 * core function to access sclp interface 4 * 5 * S390 version 6 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation 7 * Author(s): Martin Peschke <mpeschke@de.ibm.com> 8 * Martin Schwidefsky <schwidefsky@de.ibm.com> 9 */ 10 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 <asm/types.h> 20 #include <asm/s390_ext.h> 21 22 #include "sclp.h" 23 24 #define SCLP_HEADER "sclp: " 25 26 /* Structure for register_early_external_interrupt. */ 27 static ext_int_info_t ext_int_info_hwc; 28 29 /* Lock to protect internal data consistency. */ 30 static DEFINE_SPINLOCK(sclp_lock); 31 32 /* Mask of events that we can receive from the sclp interface. */ 33 static sccb_mask_t sclp_receive_mask; 34 35 /* Mask of events that we can send to 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 /* Timer for request retries. */ 51 static struct timer_list sclp_request_timer; 52 53 /* Internal state: is the driver initialized? */ 54 static volatile enum sclp_init_state_t { 55 sclp_init_state_uninitialized, 56 sclp_init_state_initializing, 57 sclp_init_state_initialized 58 } sclp_init_state = sclp_init_state_uninitialized; 59 60 /* Internal state: is a request active at the sclp? */ 61 static volatile enum sclp_running_state_t { 62 sclp_running_state_idle, 63 sclp_running_state_running, 64 sclp_running_state_reset_pending 65 } sclp_running_state = sclp_running_state_idle; 66 67 /* Internal state: is a read request pending? */ 68 static volatile enum sclp_reading_state_t { 69 sclp_reading_state_idle, 70 sclp_reading_state_reading 71 } sclp_reading_state = sclp_reading_state_idle; 72 73 /* Internal state: is the driver currently serving requests? */ 74 static volatile enum sclp_activation_state_t { 75 sclp_activation_state_active, 76 sclp_activation_state_deactivating, 77 sclp_activation_state_inactive, 78 sclp_activation_state_activating 79 } sclp_activation_state = sclp_activation_state_active; 80 81 /* Internal state: is an init mask request pending? */ 82 static volatile enum sclp_mask_state_t { 83 sclp_mask_state_idle, 84 sclp_mask_state_initializing 85 } sclp_mask_state = sclp_mask_state_idle; 86 87 /* Maximum retry counts */ 88 #define SCLP_INIT_RETRY 3 89 #define SCLP_MASK_RETRY 3 90 91 /* Timeout intervals in seconds.*/ 92 #define SCLP_BUSY_INTERVAL 10 93 #define SCLP_RETRY_INTERVAL 30 94 95 static void sclp_process_queue(void); 96 static int sclp_init_mask(int calculate); 97 static int sclp_init(void); 98 99 /* Perform service call. Return 0 on success, non-zero otherwise. */ 100 int 101 sclp_service_call(sclp_cmdw_t command, void *sccb) 102 { 103 int cc; 104 105 asm volatile( 106 " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 107 " ipm %0\n" 108 " srl %0,28" 109 : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) 110 : "cc", "memory"); 111 if (cc == 3) 112 return -EIO; 113 if (cc == 2) 114 return -EBUSY; 115 return 0; 116 } 117 118 static inline void __sclp_make_read_req(void); 119 120 static void 121 __sclp_queue_read_req(void) 122 { 123 if (sclp_reading_state == sclp_reading_state_idle) { 124 sclp_reading_state = sclp_reading_state_reading; 125 __sclp_make_read_req(); 126 /* Add request to head of queue */ 127 list_add(&sclp_read_req.list, &sclp_req_queue); 128 } 129 } 130 131 /* Set up request retry timer. Called while sclp_lock is locked. */ 132 static inline void 133 __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), 134 unsigned long data) 135 { 136 del_timer(&sclp_request_timer); 137 sclp_request_timer.function = function; 138 sclp_request_timer.data = data; 139 sclp_request_timer.expires = jiffies + time; 140 add_timer(&sclp_request_timer); 141 } 142 143 /* Request timeout handler. Restart the request queue. If DATA is non-zero, 144 * force restart of running request. */ 145 static void 146 sclp_request_timeout(unsigned long data) 147 { 148 unsigned long flags; 149 150 spin_lock_irqsave(&sclp_lock, flags); 151 if (data) { 152 if (sclp_running_state == sclp_running_state_running) { 153 /* Break running state and queue NOP read event request 154 * to get a defined interface state. */ 155 __sclp_queue_read_req(); 156 sclp_running_state = sclp_running_state_idle; 157 } 158 } else { 159 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 160 sclp_request_timeout, 0); 161 } 162 spin_unlock_irqrestore(&sclp_lock, flags); 163 sclp_process_queue(); 164 } 165 166 /* Try to start a request. Return zero if the request was successfully 167 * started or if it will be started at a later time. Return non-zero otherwise. 168 * Called while sclp_lock is locked. */ 169 static int 170 __sclp_start_request(struct sclp_req *req) 171 { 172 int rc; 173 174 if (sclp_running_state != sclp_running_state_idle) 175 return 0; 176 del_timer(&sclp_request_timer); 177 rc = sclp_service_call(req->command, req->sccb); 178 req->start_count++; 179 180 if (rc == 0) { 181 /* Sucessfully started request */ 182 req->status = SCLP_REQ_RUNNING; 183 sclp_running_state = sclp_running_state_running; 184 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 185 sclp_request_timeout, 1); 186 return 0; 187 } else if (rc == -EBUSY) { 188 /* Try again later */ 189 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 190 sclp_request_timeout, 0); 191 return 0; 192 } 193 /* Request failed */ 194 req->status = SCLP_REQ_FAILED; 195 return rc; 196 } 197 198 /* Try to start queued requests. */ 199 static void 200 sclp_process_queue(void) 201 { 202 struct sclp_req *req; 203 int rc; 204 unsigned long flags; 205 206 spin_lock_irqsave(&sclp_lock, flags); 207 if (sclp_running_state != sclp_running_state_idle) { 208 spin_unlock_irqrestore(&sclp_lock, flags); 209 return; 210 } 211 del_timer(&sclp_request_timer); 212 while (!list_empty(&sclp_req_queue)) { 213 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 214 rc = __sclp_start_request(req); 215 if (rc == 0) 216 break; 217 /* Request failed */ 218 if (req->start_count > 1) { 219 /* Cannot abort already submitted request - could still 220 * be active at the SCLP */ 221 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 222 sclp_request_timeout, 0); 223 break; 224 } 225 /* Post-processing for aborted request */ 226 list_del(&req->list); 227 if (req->callback) { 228 spin_unlock_irqrestore(&sclp_lock, flags); 229 req->callback(req, req->callback_data); 230 spin_lock_irqsave(&sclp_lock, flags); 231 } 232 } 233 spin_unlock_irqrestore(&sclp_lock, flags); 234 } 235 236 /* Queue a new request. Return zero on success, non-zero otherwise. */ 237 int 238 sclp_add_request(struct sclp_req *req) 239 { 240 unsigned long flags; 241 int rc; 242 243 spin_lock_irqsave(&sclp_lock, flags); 244 if ((sclp_init_state != sclp_init_state_initialized || 245 sclp_activation_state != sclp_activation_state_active) && 246 req != &sclp_init_req) { 247 spin_unlock_irqrestore(&sclp_lock, flags); 248 return -EIO; 249 } 250 req->status = SCLP_REQ_QUEUED; 251 req->start_count = 0; 252 list_add_tail(&req->list, &sclp_req_queue); 253 rc = 0; 254 /* Start if request is first in list */ 255 if (sclp_running_state == sclp_running_state_idle && 256 req->list.prev == &sclp_req_queue) { 257 rc = __sclp_start_request(req); 258 if (rc) 259 list_del(&req->list); 260 } 261 spin_unlock_irqrestore(&sclp_lock, flags); 262 return rc; 263 } 264 265 EXPORT_SYMBOL(sclp_add_request); 266 267 /* Dispatch events found in request buffer to registered listeners. Return 0 268 * if all events were dispatched, non-zero otherwise. */ 269 static int 270 sclp_dispatch_evbufs(struct sccb_header *sccb) 271 { 272 unsigned long flags; 273 struct evbuf_header *evbuf; 274 struct list_head *l; 275 struct sclp_register *reg; 276 int offset; 277 int rc; 278 279 spin_lock_irqsave(&sclp_lock, flags); 280 rc = 0; 281 for (offset = sizeof(struct sccb_header); offset < sccb->length; 282 offset += evbuf->length) { 283 /* Search for event handler */ 284 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 285 reg = NULL; 286 list_for_each(l, &sclp_reg_list) { 287 reg = list_entry(l, struct sclp_register, list); 288 if (reg->receive_mask & (1 << (32 - evbuf->type))) 289 break; 290 else 291 reg = NULL; 292 } 293 if (reg && reg->receiver_fn) { 294 spin_unlock_irqrestore(&sclp_lock, flags); 295 reg->receiver_fn(evbuf); 296 spin_lock_irqsave(&sclp_lock, flags); 297 } else if (reg == NULL) 298 rc = -ENOSYS; 299 } 300 spin_unlock_irqrestore(&sclp_lock, flags); 301 return rc; 302 } 303 304 /* Read event data request callback. */ 305 static void 306 sclp_read_cb(struct sclp_req *req, void *data) 307 { 308 unsigned long flags; 309 struct sccb_header *sccb; 310 311 sccb = (struct sccb_header *) req->sccb; 312 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 313 sccb->response_code == 0x220)) 314 sclp_dispatch_evbufs(sccb); 315 spin_lock_irqsave(&sclp_lock, flags); 316 sclp_reading_state = sclp_reading_state_idle; 317 spin_unlock_irqrestore(&sclp_lock, flags); 318 } 319 320 /* Prepare read event data request. Called while sclp_lock is locked. */ 321 static inline void 322 __sclp_make_read_req(void) 323 { 324 struct sccb_header *sccb; 325 326 sccb = (struct sccb_header *) sclp_read_sccb; 327 clear_page(sccb); 328 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 329 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 330 sclp_read_req.status = SCLP_REQ_QUEUED; 331 sclp_read_req.start_count = 0; 332 sclp_read_req.callback = sclp_read_cb; 333 sclp_read_req.sccb = sccb; 334 sccb->length = PAGE_SIZE; 335 sccb->function_code = 0; 336 sccb->control_mask[2] = 0x80; 337 } 338 339 /* Search request list for request with matching sccb. Return request if found, 340 * NULL otherwise. Called while sclp_lock is locked. */ 341 static inline struct sclp_req * 342 __sclp_find_req(u32 sccb) 343 { 344 struct list_head *l; 345 struct sclp_req *req; 346 347 list_for_each(l, &sclp_req_queue) { 348 req = list_entry(l, struct sclp_req, list); 349 if (sccb == (u32) (addr_t) req->sccb) 350 return req; 351 } 352 return NULL; 353 } 354 355 /* Handler for external interruption. Perform request post-processing. 356 * Prepare read event data request if necessary. Start processing of next 357 * request on queue. */ 358 static void 359 sclp_interrupt_handler(__u16 code) 360 { 361 struct sclp_req *req; 362 u32 finished_sccb; 363 u32 evbuf_pending; 364 365 spin_lock(&sclp_lock); 366 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 367 evbuf_pending = S390_lowcore.ext_params & 0x3; 368 if (finished_sccb) { 369 del_timer(&sclp_request_timer); 370 sclp_running_state = sclp_running_state_reset_pending; 371 req = __sclp_find_req(finished_sccb); 372 if (req) { 373 /* Request post-processing */ 374 list_del(&req->list); 375 req->status = SCLP_REQ_DONE; 376 if (req->callback) { 377 spin_unlock(&sclp_lock); 378 req->callback(req, req->callback_data); 379 spin_lock(&sclp_lock); 380 } 381 } 382 sclp_running_state = sclp_running_state_idle; 383 } 384 if (evbuf_pending && sclp_receive_mask != 0 && 385 sclp_activation_state == sclp_activation_state_active) 386 __sclp_queue_read_req(); 387 spin_unlock(&sclp_lock); 388 sclp_process_queue(); 389 } 390 391 /* Convert interval in jiffies to TOD ticks. */ 392 static inline u64 393 sclp_tod_from_jiffies(unsigned long jiffies) 394 { 395 return (u64) (jiffies / HZ) << 32; 396 } 397 398 /* Wait until a currently running request finished. Note: while this function 399 * is running, no timers are served on the calling CPU. */ 400 void 401 sclp_sync_wait(void) 402 { 403 unsigned long flags; 404 unsigned long cr0, cr0_sync; 405 u64 timeout; 406 int irq_context; 407 408 /* We'll be disabling timer interrupts, so we need a custom timeout 409 * mechanism */ 410 timeout = 0; 411 if (timer_pending(&sclp_request_timer)) { 412 /* Get timeout TOD value */ 413 timeout = get_clock() + 414 sclp_tod_from_jiffies(sclp_request_timer.expires - 415 jiffies); 416 } 417 local_irq_save(flags); 418 /* Prevent bottom half from executing once we force interrupts open */ 419 irq_context = in_interrupt(); 420 if (!irq_context) 421 local_bh_disable(); 422 /* Enable service-signal interruption, disable timer interrupts */ 423 trace_hardirqs_on(); 424 __ctl_store(cr0, 0, 0); 425 cr0_sync = cr0; 426 cr0_sync |= 0x00000200; 427 cr0_sync &= 0xFFFFF3AC; 428 __ctl_load(cr0_sync, 0, 0); 429 __raw_local_irq_stosm(0x01); 430 /* Loop until driver state indicates finished request */ 431 while (sclp_running_state != sclp_running_state_idle) { 432 /* Check for expired request timer */ 433 if (timer_pending(&sclp_request_timer) && 434 get_clock() > timeout && 435 del_timer(&sclp_request_timer)) 436 sclp_request_timer.function(sclp_request_timer.data); 437 cpu_relax(); 438 } 439 local_irq_disable(); 440 __ctl_load(cr0, 0, 0); 441 if (!irq_context) 442 _local_bh_enable(); 443 local_irq_restore(flags); 444 } 445 446 EXPORT_SYMBOL(sclp_sync_wait); 447 448 /* Dispatch changes in send and receive mask to registered listeners. */ 449 static void 450 sclp_dispatch_state_change(void) 451 { 452 struct list_head *l; 453 struct sclp_register *reg; 454 unsigned long flags; 455 sccb_mask_t receive_mask; 456 sccb_mask_t send_mask; 457 458 do { 459 spin_lock_irqsave(&sclp_lock, flags); 460 reg = NULL; 461 list_for_each(l, &sclp_reg_list) { 462 reg = list_entry(l, struct sclp_register, list); 463 receive_mask = reg->receive_mask & sclp_receive_mask; 464 send_mask = reg->send_mask & sclp_send_mask; 465 if (reg->sclp_receive_mask != receive_mask || 466 reg->sclp_send_mask != send_mask) { 467 reg->sclp_receive_mask = receive_mask; 468 reg->sclp_send_mask = send_mask; 469 break; 470 } else 471 reg = NULL; 472 } 473 spin_unlock_irqrestore(&sclp_lock, flags); 474 if (reg && reg->state_change_fn) 475 reg->state_change_fn(reg); 476 } while (reg); 477 } 478 479 struct sclp_statechangebuf { 480 struct evbuf_header header; 481 u8 validity_sclp_active_facility_mask : 1; 482 u8 validity_sclp_receive_mask : 1; 483 u8 validity_sclp_send_mask : 1; 484 u8 validity_read_data_function_mask : 1; 485 u16 _zeros : 12; 486 u16 mask_length; 487 u64 sclp_active_facility_mask; 488 sccb_mask_t sclp_receive_mask; 489 sccb_mask_t sclp_send_mask; 490 u32 read_data_function_mask; 491 } __attribute__((packed)); 492 493 494 /* State change event callback. Inform listeners of changes. */ 495 static void 496 sclp_state_change_cb(struct evbuf_header *evbuf) 497 { 498 unsigned long flags; 499 struct sclp_statechangebuf *scbuf; 500 501 scbuf = (struct sclp_statechangebuf *) evbuf; 502 if (scbuf->mask_length != sizeof(sccb_mask_t)) 503 return; 504 spin_lock_irqsave(&sclp_lock, flags); 505 if (scbuf->validity_sclp_receive_mask) 506 sclp_receive_mask = scbuf->sclp_receive_mask; 507 if (scbuf->validity_sclp_send_mask) 508 sclp_send_mask = scbuf->sclp_send_mask; 509 spin_unlock_irqrestore(&sclp_lock, flags); 510 sclp_dispatch_state_change(); 511 } 512 513 static struct sclp_register sclp_state_change_event = { 514 .receive_mask = EVTYP_STATECHANGE_MASK, 515 .receiver_fn = sclp_state_change_cb 516 }; 517 518 /* Calculate receive and send mask of currently registered listeners. 519 * Called while sclp_lock is locked. */ 520 static inline void 521 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 522 { 523 struct list_head *l; 524 struct sclp_register *t; 525 526 *receive_mask = 0; 527 *send_mask = 0; 528 list_for_each(l, &sclp_reg_list) { 529 t = list_entry(l, struct sclp_register, list); 530 *receive_mask |= t->receive_mask; 531 *send_mask |= t->send_mask; 532 } 533 } 534 535 /* Register event listener. Return 0 on success, non-zero otherwise. */ 536 int 537 sclp_register(struct sclp_register *reg) 538 { 539 unsigned long flags; 540 sccb_mask_t receive_mask; 541 sccb_mask_t send_mask; 542 int rc; 543 544 rc = sclp_init(); 545 if (rc) 546 return rc; 547 spin_lock_irqsave(&sclp_lock, flags); 548 /* Check event mask for collisions */ 549 __sclp_get_mask(&receive_mask, &send_mask); 550 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 551 spin_unlock_irqrestore(&sclp_lock, flags); 552 return -EBUSY; 553 } 554 /* Trigger initial state change callback */ 555 reg->sclp_receive_mask = 0; 556 reg->sclp_send_mask = 0; 557 list_add(®->list, &sclp_reg_list); 558 spin_unlock_irqrestore(&sclp_lock, flags); 559 rc = sclp_init_mask(1); 560 if (rc) { 561 spin_lock_irqsave(&sclp_lock, flags); 562 list_del(®->list); 563 spin_unlock_irqrestore(&sclp_lock, flags); 564 } 565 return rc; 566 } 567 568 EXPORT_SYMBOL(sclp_register); 569 570 /* Unregister event listener. */ 571 void 572 sclp_unregister(struct sclp_register *reg) 573 { 574 unsigned long flags; 575 576 spin_lock_irqsave(&sclp_lock, flags); 577 list_del(®->list); 578 spin_unlock_irqrestore(&sclp_lock, flags); 579 sclp_init_mask(1); 580 } 581 582 EXPORT_SYMBOL(sclp_unregister); 583 584 /* Remove event buffers which are marked processed. Return the number of 585 * remaining event buffers. */ 586 int 587 sclp_remove_processed(struct sccb_header *sccb) 588 { 589 struct evbuf_header *evbuf; 590 int unprocessed; 591 u16 remaining; 592 593 evbuf = (struct evbuf_header *) (sccb + 1); 594 unprocessed = 0; 595 remaining = sccb->length - sizeof(struct sccb_header); 596 while (remaining > 0) { 597 remaining -= evbuf->length; 598 if (evbuf->flags & 0x80) { 599 sccb->length -= evbuf->length; 600 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 601 remaining); 602 } else { 603 unprocessed++; 604 evbuf = (struct evbuf_header *) 605 ((addr_t) evbuf + evbuf->length); 606 } 607 } 608 return unprocessed; 609 } 610 611 EXPORT_SYMBOL(sclp_remove_processed); 612 613 struct init_sccb { 614 struct sccb_header header; 615 u16 _reserved; 616 u16 mask_length; 617 sccb_mask_t receive_mask; 618 sccb_mask_t send_mask; 619 sccb_mask_t sclp_send_mask; 620 sccb_mask_t sclp_receive_mask; 621 } __attribute__((packed)); 622 623 /* Prepare init mask request. Called while sclp_lock is locked. */ 624 static inline void 625 __sclp_make_init_req(u32 receive_mask, u32 send_mask) 626 { 627 struct init_sccb *sccb; 628 629 sccb = (struct init_sccb *) sclp_init_sccb; 630 clear_page(sccb); 631 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 632 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 633 sclp_init_req.status = SCLP_REQ_FILLED; 634 sclp_init_req.start_count = 0; 635 sclp_init_req.callback = NULL; 636 sclp_init_req.callback_data = NULL; 637 sclp_init_req.sccb = sccb; 638 sccb->header.length = sizeof(struct init_sccb); 639 sccb->mask_length = sizeof(sccb_mask_t); 640 sccb->receive_mask = receive_mask; 641 sccb->send_mask = send_mask; 642 sccb->sclp_receive_mask = 0; 643 sccb->sclp_send_mask = 0; 644 } 645 646 /* Start init mask request. If calculate is non-zero, calculate the mask as 647 * requested by registered listeners. Use zero mask otherwise. Return 0 on 648 * success, non-zero otherwise. */ 649 static int 650 sclp_init_mask(int calculate) 651 { 652 unsigned long flags; 653 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 654 sccb_mask_t receive_mask; 655 sccb_mask_t send_mask; 656 int retry; 657 int rc; 658 unsigned long wait; 659 660 spin_lock_irqsave(&sclp_lock, flags); 661 /* Check if interface is in appropriate state */ 662 if (sclp_mask_state != sclp_mask_state_idle) { 663 spin_unlock_irqrestore(&sclp_lock, flags); 664 return -EBUSY; 665 } 666 if (sclp_activation_state == sclp_activation_state_inactive) { 667 spin_unlock_irqrestore(&sclp_lock, flags); 668 return -EINVAL; 669 } 670 sclp_mask_state = sclp_mask_state_initializing; 671 /* Determine mask */ 672 if (calculate) 673 __sclp_get_mask(&receive_mask, &send_mask); 674 else { 675 receive_mask = 0; 676 send_mask = 0; 677 } 678 rc = -EIO; 679 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 680 /* Prepare request */ 681 __sclp_make_init_req(receive_mask, send_mask); 682 spin_unlock_irqrestore(&sclp_lock, flags); 683 if (sclp_add_request(&sclp_init_req)) { 684 /* Try again later */ 685 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 686 while (time_before(jiffies, wait)) 687 sclp_sync_wait(); 688 spin_lock_irqsave(&sclp_lock, flags); 689 continue; 690 } 691 while (sclp_init_req.status != SCLP_REQ_DONE && 692 sclp_init_req.status != SCLP_REQ_FAILED) 693 sclp_sync_wait(); 694 spin_lock_irqsave(&sclp_lock, flags); 695 if (sclp_init_req.status == SCLP_REQ_DONE && 696 sccb->header.response_code == 0x20) { 697 /* Successful request */ 698 if (calculate) { 699 sclp_receive_mask = sccb->sclp_receive_mask; 700 sclp_send_mask = sccb->sclp_send_mask; 701 } else { 702 sclp_receive_mask = 0; 703 sclp_send_mask = 0; 704 } 705 spin_unlock_irqrestore(&sclp_lock, flags); 706 sclp_dispatch_state_change(); 707 spin_lock_irqsave(&sclp_lock, flags); 708 rc = 0; 709 break; 710 } 711 } 712 sclp_mask_state = sclp_mask_state_idle; 713 spin_unlock_irqrestore(&sclp_lock, flags); 714 return rc; 715 } 716 717 /* Deactivate SCLP interface. On success, new requests will be rejected, 718 * events will no longer be dispatched. Return 0 on success, non-zero 719 * otherwise. */ 720 int 721 sclp_deactivate(void) 722 { 723 unsigned long flags; 724 int rc; 725 726 spin_lock_irqsave(&sclp_lock, flags); 727 /* Deactivate can only be called when active */ 728 if (sclp_activation_state != sclp_activation_state_active) { 729 spin_unlock_irqrestore(&sclp_lock, flags); 730 return -EINVAL; 731 } 732 sclp_activation_state = sclp_activation_state_deactivating; 733 spin_unlock_irqrestore(&sclp_lock, flags); 734 rc = sclp_init_mask(0); 735 spin_lock_irqsave(&sclp_lock, flags); 736 if (rc == 0) 737 sclp_activation_state = sclp_activation_state_inactive; 738 else 739 sclp_activation_state = sclp_activation_state_active; 740 spin_unlock_irqrestore(&sclp_lock, flags); 741 return rc; 742 } 743 744 EXPORT_SYMBOL(sclp_deactivate); 745 746 /* Reactivate SCLP interface after sclp_deactivate. On success, new 747 * requests will be accepted, events will be dispatched again. Return 0 on 748 * success, non-zero otherwise. */ 749 int 750 sclp_reactivate(void) 751 { 752 unsigned long flags; 753 int rc; 754 755 spin_lock_irqsave(&sclp_lock, flags); 756 /* Reactivate can only be called when inactive */ 757 if (sclp_activation_state != sclp_activation_state_inactive) { 758 spin_unlock_irqrestore(&sclp_lock, flags); 759 return -EINVAL; 760 } 761 sclp_activation_state = sclp_activation_state_activating; 762 spin_unlock_irqrestore(&sclp_lock, flags); 763 rc = sclp_init_mask(1); 764 spin_lock_irqsave(&sclp_lock, flags); 765 if (rc == 0) 766 sclp_activation_state = sclp_activation_state_active; 767 else 768 sclp_activation_state = sclp_activation_state_inactive; 769 spin_unlock_irqrestore(&sclp_lock, flags); 770 return rc; 771 } 772 773 EXPORT_SYMBOL(sclp_reactivate); 774 775 /* Handler for external interruption used during initialization. Modify 776 * request state to done. */ 777 static void 778 sclp_check_handler(__u16 code) 779 { 780 u32 finished_sccb; 781 782 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 783 /* Is this the interrupt we are waiting for? */ 784 if (finished_sccb == 0) 785 return; 786 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) { 787 printk(KERN_WARNING SCLP_HEADER "unsolicited interrupt " 788 "for buffer at 0x%x\n", finished_sccb); 789 return; 790 } 791 spin_lock(&sclp_lock); 792 if (sclp_running_state == sclp_running_state_running) { 793 sclp_init_req.status = SCLP_REQ_DONE; 794 sclp_running_state = sclp_running_state_idle; 795 } 796 spin_unlock(&sclp_lock); 797 } 798 799 /* Initial init mask request timed out. Modify request state to failed. */ 800 static void 801 sclp_check_timeout(unsigned long data) 802 { 803 unsigned long flags; 804 805 spin_lock_irqsave(&sclp_lock, flags); 806 if (sclp_running_state == sclp_running_state_running) { 807 sclp_init_req.status = SCLP_REQ_FAILED; 808 sclp_running_state = sclp_running_state_idle; 809 } 810 spin_unlock_irqrestore(&sclp_lock, flags); 811 } 812 813 /* Perform a check of the SCLP interface. Return zero if the interface is 814 * available and there are no pending requests from a previous instance. 815 * Return non-zero otherwise. */ 816 static int 817 sclp_check_interface(void) 818 { 819 struct init_sccb *sccb; 820 unsigned long flags; 821 int retry; 822 int rc; 823 824 spin_lock_irqsave(&sclp_lock, flags); 825 /* Prepare init mask command */ 826 rc = register_early_external_interrupt(0x2401, sclp_check_handler, 827 &ext_int_info_hwc); 828 if (rc) { 829 spin_unlock_irqrestore(&sclp_lock, flags); 830 return rc; 831 } 832 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 833 __sclp_make_init_req(0, 0); 834 sccb = (struct init_sccb *) sclp_init_req.sccb; 835 rc = sclp_service_call(sclp_init_req.command, sccb); 836 if (rc == -EIO) 837 break; 838 sclp_init_req.status = SCLP_REQ_RUNNING; 839 sclp_running_state = sclp_running_state_running; 840 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 841 sclp_check_timeout, 0); 842 spin_unlock_irqrestore(&sclp_lock, flags); 843 /* Enable service-signal interruption - needs to happen 844 * with IRQs enabled. */ 845 ctl_set_bit(0, 9); 846 /* Wait for signal from interrupt or timeout */ 847 sclp_sync_wait(); 848 /* Disable service-signal interruption - needs to happen 849 * with IRQs enabled. */ 850 ctl_clear_bit(0,9); 851 spin_lock_irqsave(&sclp_lock, flags); 852 del_timer(&sclp_request_timer); 853 if (sclp_init_req.status == SCLP_REQ_DONE && 854 sccb->header.response_code == 0x20) { 855 rc = 0; 856 break; 857 } else 858 rc = -EBUSY; 859 } 860 unregister_early_external_interrupt(0x2401, sclp_check_handler, 861 &ext_int_info_hwc); 862 spin_unlock_irqrestore(&sclp_lock, flags); 863 return rc; 864 } 865 866 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP 867 * events from interfering with rebooted system. */ 868 static int 869 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 870 { 871 sclp_deactivate(); 872 return NOTIFY_DONE; 873 } 874 875 static struct notifier_block sclp_reboot_notifier = { 876 .notifier_call = sclp_reboot_event 877 }; 878 879 /* Initialize SCLP driver. Return zero if driver is operational, non-zero 880 * otherwise. */ 881 static int 882 sclp_init(void) 883 { 884 unsigned long flags; 885 int rc; 886 887 if (!MACHINE_HAS_SCLP) 888 return -ENODEV; 889 spin_lock_irqsave(&sclp_lock, flags); 890 /* Check for previous or running initialization */ 891 if (sclp_init_state != sclp_init_state_uninitialized) { 892 spin_unlock_irqrestore(&sclp_lock, flags); 893 return 0; 894 } 895 sclp_init_state = sclp_init_state_initializing; 896 /* Set up variables */ 897 INIT_LIST_HEAD(&sclp_req_queue); 898 INIT_LIST_HEAD(&sclp_reg_list); 899 list_add(&sclp_state_change_event.list, &sclp_reg_list); 900 init_timer(&sclp_request_timer); 901 /* Check interface */ 902 spin_unlock_irqrestore(&sclp_lock, flags); 903 rc = sclp_check_interface(); 904 spin_lock_irqsave(&sclp_lock, flags); 905 if (rc) { 906 sclp_init_state = sclp_init_state_uninitialized; 907 spin_unlock_irqrestore(&sclp_lock, flags); 908 return rc; 909 } 910 /* Register reboot handler */ 911 rc = register_reboot_notifier(&sclp_reboot_notifier); 912 if (rc) { 913 sclp_init_state = sclp_init_state_uninitialized; 914 spin_unlock_irqrestore(&sclp_lock, flags); 915 return rc; 916 } 917 /* Register interrupt handler */ 918 rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler, 919 &ext_int_info_hwc); 920 if (rc) { 921 unregister_reboot_notifier(&sclp_reboot_notifier); 922 sclp_init_state = sclp_init_state_uninitialized; 923 spin_unlock_irqrestore(&sclp_lock, flags); 924 return rc; 925 } 926 sclp_init_state = sclp_init_state_initialized; 927 spin_unlock_irqrestore(&sclp_lock, flags); 928 /* Enable service-signal external interruption - needs to happen with 929 * IRQs enabled. */ 930 ctl_set_bit(0, 9); 931 sclp_init_mask(1); 932 return 0; 933 } 934 935 static __init int sclp_initcall(void) 936 { 937 return sclp_init(); 938 } 939 940 arch_initcall(sclp_initcall); 941