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 <asm/types.h> 19 #include <asm/s390_ext.h> 20 21 #include "sclp.h" 22 23 #define SCLP_HEADER "sclp: " 24 25 /* Structure for register_early_external_interrupt. */ 26 static ext_int_info_t ext_int_info_hwc; 27 28 /* Lock to protect internal data consistency. */ 29 static DEFINE_SPINLOCK(sclp_lock); 30 31 /* Mask of events that we can receive from the sclp interface. */ 32 static sccb_mask_t sclp_receive_mask; 33 34 /* Mask of events that we can send to the sclp interface. */ 35 static sccb_mask_t sclp_send_mask; 36 37 /* List of registered event listeners and senders. */ 38 static struct list_head sclp_reg_list; 39 40 /* List of queued requests. */ 41 static struct list_head sclp_req_queue; 42 43 /* Data for read and and init requests. */ 44 static struct sclp_req sclp_read_req; 45 static struct sclp_req sclp_init_req; 46 static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 47 static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 48 49 /* Timer for request retries. */ 50 static struct timer_list sclp_request_timer; 51 52 /* Internal state: is the driver initialized? */ 53 static volatile enum sclp_init_state_t { 54 sclp_init_state_uninitialized, 55 sclp_init_state_initializing, 56 sclp_init_state_initialized 57 } sclp_init_state = sclp_init_state_uninitialized; 58 59 /* Internal state: is a request active at the sclp? */ 60 static volatile enum sclp_running_state_t { 61 sclp_running_state_idle, 62 sclp_running_state_running, 63 sclp_running_state_reset_pending 64 } sclp_running_state = sclp_running_state_idle; 65 66 /* Internal state: is a read request pending? */ 67 static volatile enum sclp_reading_state_t { 68 sclp_reading_state_idle, 69 sclp_reading_state_reading 70 } sclp_reading_state = sclp_reading_state_idle; 71 72 /* Internal state: is the driver currently serving requests? */ 73 static volatile enum sclp_activation_state_t { 74 sclp_activation_state_active, 75 sclp_activation_state_deactivating, 76 sclp_activation_state_inactive, 77 sclp_activation_state_activating 78 } sclp_activation_state = sclp_activation_state_active; 79 80 /* Internal state: is an init mask request pending? */ 81 static volatile enum sclp_mask_state_t { 82 sclp_mask_state_idle, 83 sclp_mask_state_initializing 84 } sclp_mask_state = sclp_mask_state_idle; 85 86 /* Maximum retry counts */ 87 #define SCLP_INIT_RETRY 3 88 #define SCLP_MASK_RETRY 3 89 90 /* Timeout intervals in seconds.*/ 91 #define SCLP_BUSY_INTERVAL 10 92 #define SCLP_RETRY_INTERVAL 30 93 94 static void sclp_process_queue(void); 95 static int sclp_init_mask(int calculate); 96 static int sclp_init(void); 97 98 /* Perform service call. Return 0 on success, non-zero otherwise. */ 99 int 100 sclp_service_call(sclp_cmdw_t command, void *sccb) 101 { 102 int cc; 103 104 asm volatile( 105 " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 106 " ipm %0\n" 107 " srl %0,28" 108 : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) 109 : "cc", "memory"); 110 if (cc == 3) 111 return -EIO; 112 if (cc == 2) 113 return -EBUSY; 114 return 0; 115 } 116 117 static inline void __sclp_make_read_req(void); 118 119 static void 120 __sclp_queue_read_req(void) 121 { 122 if (sclp_reading_state == sclp_reading_state_idle) { 123 sclp_reading_state = sclp_reading_state_reading; 124 __sclp_make_read_req(); 125 /* Add request to head of queue */ 126 list_add(&sclp_read_req.list, &sclp_req_queue); 127 } 128 } 129 130 /* Set up request retry timer. Called while sclp_lock is locked. */ 131 static inline void 132 __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), 133 unsigned long data) 134 { 135 del_timer(&sclp_request_timer); 136 sclp_request_timer.function = function; 137 sclp_request_timer.data = data; 138 sclp_request_timer.expires = jiffies + time; 139 add_timer(&sclp_request_timer); 140 } 141 142 /* Request timeout handler. Restart the request queue. If DATA is non-zero, 143 * force restart of running request. */ 144 static void 145 sclp_request_timeout(unsigned long data) 146 { 147 unsigned long flags; 148 149 spin_lock_irqsave(&sclp_lock, flags); 150 if (data) { 151 if (sclp_running_state == sclp_running_state_running) { 152 /* Break running state and queue NOP read event request 153 * to get a defined interface state. */ 154 __sclp_queue_read_req(); 155 sclp_running_state = sclp_running_state_idle; 156 } 157 } else { 158 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 159 sclp_request_timeout, 0); 160 } 161 spin_unlock_irqrestore(&sclp_lock, flags); 162 sclp_process_queue(); 163 } 164 165 /* Try to start a request. Return zero if the request was successfully 166 * started or if it will be started at a later time. Return non-zero otherwise. 167 * Called while sclp_lock is locked. */ 168 static int 169 __sclp_start_request(struct sclp_req *req) 170 { 171 int rc; 172 173 if (sclp_running_state != sclp_running_state_idle) 174 return 0; 175 del_timer(&sclp_request_timer); 176 rc = sclp_service_call(req->command, req->sccb); 177 req->start_count++; 178 179 if (rc == 0) { 180 /* Sucessfully started request */ 181 req->status = SCLP_REQ_RUNNING; 182 sclp_running_state = sclp_running_state_running; 183 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 184 sclp_request_timeout, 1); 185 return 0; 186 } else if (rc == -EBUSY) { 187 /* Try again later */ 188 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 189 sclp_request_timeout, 0); 190 return 0; 191 } 192 /* Request failed */ 193 req->status = SCLP_REQ_FAILED; 194 return rc; 195 } 196 197 /* Try to start queued requests. */ 198 static void 199 sclp_process_queue(void) 200 { 201 struct sclp_req *req; 202 int rc; 203 unsigned long flags; 204 205 spin_lock_irqsave(&sclp_lock, flags); 206 if (sclp_running_state != sclp_running_state_idle) { 207 spin_unlock_irqrestore(&sclp_lock, flags); 208 return; 209 } 210 del_timer(&sclp_request_timer); 211 while (!list_empty(&sclp_req_queue)) { 212 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 213 rc = __sclp_start_request(req); 214 if (rc == 0) 215 break; 216 /* Request failed */ 217 if (req->start_count > 1) { 218 /* Cannot abort already submitted request - could still 219 * be active at the SCLP */ 220 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 221 sclp_request_timeout, 0); 222 break; 223 } 224 /* Post-processing for aborted request */ 225 list_del(&req->list); 226 if (req->callback) { 227 spin_unlock_irqrestore(&sclp_lock, flags); 228 req->callback(req, req->callback_data); 229 spin_lock_irqsave(&sclp_lock, flags); 230 } 231 } 232 spin_unlock_irqrestore(&sclp_lock, flags); 233 } 234 235 /* Queue a new request. Return zero on success, non-zero otherwise. */ 236 int 237 sclp_add_request(struct sclp_req *req) 238 { 239 unsigned long flags; 240 int rc; 241 242 spin_lock_irqsave(&sclp_lock, flags); 243 if ((sclp_init_state != sclp_init_state_initialized || 244 sclp_activation_state != sclp_activation_state_active) && 245 req != &sclp_init_req) { 246 spin_unlock_irqrestore(&sclp_lock, flags); 247 return -EIO; 248 } 249 req->status = SCLP_REQ_QUEUED; 250 req->start_count = 0; 251 list_add_tail(&req->list, &sclp_req_queue); 252 rc = 0; 253 /* Start if request is first in list */ 254 if (sclp_running_state == sclp_running_state_idle && 255 req->list.prev == &sclp_req_queue) { 256 rc = __sclp_start_request(req); 257 if (rc) 258 list_del(&req->list); 259 } 260 spin_unlock_irqrestore(&sclp_lock, flags); 261 return rc; 262 } 263 264 EXPORT_SYMBOL(sclp_add_request); 265 266 /* Dispatch events found in request buffer to registered listeners. Return 0 267 * if all events were dispatched, non-zero otherwise. */ 268 static int 269 sclp_dispatch_evbufs(struct sccb_header *sccb) 270 { 271 unsigned long flags; 272 struct evbuf_header *evbuf; 273 struct list_head *l; 274 struct sclp_register *reg; 275 int offset; 276 int rc; 277 278 spin_lock_irqsave(&sclp_lock, flags); 279 rc = 0; 280 for (offset = sizeof(struct sccb_header); offset < sccb->length; 281 offset += evbuf->length) { 282 /* Search for event handler */ 283 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 284 reg = NULL; 285 list_for_each(l, &sclp_reg_list) { 286 reg = list_entry(l, struct sclp_register, list); 287 if (reg->receive_mask & (1 << (32 - evbuf->type))) 288 break; 289 else 290 reg = NULL; 291 } 292 if (reg && reg->receiver_fn) { 293 spin_unlock_irqrestore(&sclp_lock, flags); 294 reg->receiver_fn(evbuf); 295 spin_lock_irqsave(&sclp_lock, flags); 296 } else if (reg == NULL) 297 rc = -ENOSYS; 298 } 299 spin_unlock_irqrestore(&sclp_lock, flags); 300 return rc; 301 } 302 303 /* Read event data request callback. */ 304 static void 305 sclp_read_cb(struct sclp_req *req, void *data) 306 { 307 unsigned long flags; 308 struct sccb_header *sccb; 309 310 sccb = (struct sccb_header *) req->sccb; 311 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 312 sccb->response_code == 0x220)) 313 sclp_dispatch_evbufs(sccb); 314 spin_lock_irqsave(&sclp_lock, flags); 315 sclp_reading_state = sclp_reading_state_idle; 316 spin_unlock_irqrestore(&sclp_lock, flags); 317 } 318 319 /* Prepare read event data request. Called while sclp_lock is locked. */ 320 static inline void 321 __sclp_make_read_req(void) 322 { 323 struct sccb_header *sccb; 324 325 sccb = (struct sccb_header *) sclp_read_sccb; 326 clear_page(sccb); 327 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 328 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 329 sclp_read_req.status = SCLP_REQ_QUEUED; 330 sclp_read_req.start_count = 0; 331 sclp_read_req.callback = sclp_read_cb; 332 sclp_read_req.sccb = sccb; 333 sccb->length = PAGE_SIZE; 334 sccb->function_code = 0; 335 sccb->control_mask[2] = 0x80; 336 } 337 338 /* Search request list for request with matching sccb. Return request if found, 339 * NULL otherwise. Called while sclp_lock is locked. */ 340 static inline struct sclp_req * 341 __sclp_find_req(u32 sccb) 342 { 343 struct list_head *l; 344 struct sclp_req *req; 345 346 list_for_each(l, &sclp_req_queue) { 347 req = list_entry(l, struct sclp_req, list); 348 if (sccb == (u32) (addr_t) req->sccb) 349 return req; 350 } 351 return NULL; 352 } 353 354 /* Handler for external interruption. Perform request post-processing. 355 * Prepare read event data request if necessary. Start processing of next 356 * request on queue. */ 357 static void 358 sclp_interrupt_handler(__u16 code) 359 { 360 struct sclp_req *req; 361 u32 finished_sccb; 362 u32 evbuf_pending; 363 364 spin_lock(&sclp_lock); 365 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 366 evbuf_pending = S390_lowcore.ext_params & 0x3; 367 if (finished_sccb) { 368 del_timer(&sclp_request_timer); 369 sclp_running_state = sclp_running_state_reset_pending; 370 req = __sclp_find_req(finished_sccb); 371 if (req) { 372 /* Request post-processing */ 373 list_del(&req->list); 374 req->status = SCLP_REQ_DONE; 375 if (req->callback) { 376 spin_unlock(&sclp_lock); 377 req->callback(req, req->callback_data); 378 spin_lock(&sclp_lock); 379 } 380 } 381 sclp_running_state = sclp_running_state_idle; 382 } 383 if (evbuf_pending && sclp_receive_mask != 0 && 384 sclp_activation_state == sclp_activation_state_active) 385 __sclp_queue_read_req(); 386 spin_unlock(&sclp_lock); 387 sclp_process_queue(); 388 } 389 390 /* Convert interval in jiffies to TOD ticks. */ 391 static inline u64 392 sclp_tod_from_jiffies(unsigned long jiffies) 393 { 394 return (u64) (jiffies / HZ) << 32; 395 } 396 397 /* Wait until a currently running request finished. Note: while this function 398 * is running, no timers are served on the calling CPU. */ 399 void 400 sclp_sync_wait(void) 401 { 402 unsigned long flags; 403 unsigned long cr0, cr0_sync; 404 u64 timeout; 405 int irq_context; 406 407 /* We'll be disabling timer interrupts, so we need a custom timeout 408 * mechanism */ 409 timeout = 0; 410 if (timer_pending(&sclp_request_timer)) { 411 /* Get timeout TOD value */ 412 timeout = get_clock() + 413 sclp_tod_from_jiffies(sclp_request_timer.expires - 414 jiffies); 415 } 416 local_irq_save(flags); 417 /* Prevent bottom half from executing once we force interrupts open */ 418 irq_context = in_interrupt(); 419 if (!irq_context) 420 local_bh_disable(); 421 /* Enable service-signal interruption, disable timer interrupts */ 422 trace_hardirqs_on(); 423 __ctl_store(cr0, 0, 0); 424 cr0_sync = cr0; 425 cr0_sync |= 0x00000200; 426 cr0_sync &= 0xFFFFF3AC; 427 __ctl_load(cr0_sync, 0, 0); 428 __raw_local_irq_stosm(0x01); 429 /* Loop until driver state indicates finished request */ 430 while (sclp_running_state != sclp_running_state_idle) { 431 /* Check for expired request timer */ 432 if (timer_pending(&sclp_request_timer) && 433 get_clock() > timeout && 434 del_timer(&sclp_request_timer)) 435 sclp_request_timer.function(sclp_request_timer.data); 436 cpu_relax(); 437 } 438 local_irq_disable(); 439 __ctl_load(cr0, 0, 0); 440 if (!irq_context) 441 _local_bh_enable(); 442 local_irq_restore(flags); 443 } 444 445 EXPORT_SYMBOL(sclp_sync_wait); 446 447 /* Dispatch changes in send and receive mask to registered listeners. */ 448 static void 449 sclp_dispatch_state_change(void) 450 { 451 struct list_head *l; 452 struct sclp_register *reg; 453 unsigned long flags; 454 sccb_mask_t receive_mask; 455 sccb_mask_t send_mask; 456 457 do { 458 spin_lock_irqsave(&sclp_lock, flags); 459 reg = NULL; 460 list_for_each(l, &sclp_reg_list) { 461 reg = list_entry(l, struct sclp_register, list); 462 receive_mask = reg->receive_mask & sclp_receive_mask; 463 send_mask = reg->send_mask & sclp_send_mask; 464 if (reg->sclp_receive_mask != receive_mask || 465 reg->sclp_send_mask != send_mask) { 466 reg->sclp_receive_mask = receive_mask; 467 reg->sclp_send_mask = send_mask; 468 break; 469 } else 470 reg = NULL; 471 } 472 spin_unlock_irqrestore(&sclp_lock, flags); 473 if (reg && reg->state_change_fn) 474 reg->state_change_fn(reg); 475 } while (reg); 476 } 477 478 struct sclp_statechangebuf { 479 struct evbuf_header header; 480 u8 validity_sclp_active_facility_mask : 1; 481 u8 validity_sclp_receive_mask : 1; 482 u8 validity_sclp_send_mask : 1; 483 u8 validity_read_data_function_mask : 1; 484 u16 _zeros : 12; 485 u16 mask_length; 486 u64 sclp_active_facility_mask; 487 sccb_mask_t sclp_receive_mask; 488 sccb_mask_t sclp_send_mask; 489 u32 read_data_function_mask; 490 } __attribute__((packed)); 491 492 493 /* State change event callback. Inform listeners of changes. */ 494 static void 495 sclp_state_change_cb(struct evbuf_header *evbuf) 496 { 497 unsigned long flags; 498 struct sclp_statechangebuf *scbuf; 499 500 scbuf = (struct sclp_statechangebuf *) evbuf; 501 if (scbuf->mask_length != sizeof(sccb_mask_t)) 502 return; 503 spin_lock_irqsave(&sclp_lock, flags); 504 if (scbuf->validity_sclp_receive_mask) 505 sclp_receive_mask = scbuf->sclp_receive_mask; 506 if (scbuf->validity_sclp_send_mask) 507 sclp_send_mask = scbuf->sclp_send_mask; 508 spin_unlock_irqrestore(&sclp_lock, flags); 509 sclp_dispatch_state_change(); 510 } 511 512 static struct sclp_register sclp_state_change_event = { 513 .receive_mask = EvTyp_StateChange_Mask, 514 .receiver_fn = sclp_state_change_cb 515 }; 516 517 /* Calculate receive and send mask of currently registered listeners. 518 * Called while sclp_lock is locked. */ 519 static inline void 520 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 521 { 522 struct list_head *l; 523 struct sclp_register *t; 524 525 *receive_mask = 0; 526 *send_mask = 0; 527 list_for_each(l, &sclp_reg_list) { 528 t = list_entry(l, struct sclp_register, list); 529 *receive_mask |= t->receive_mask; 530 *send_mask |= t->send_mask; 531 } 532 } 533 534 /* Register event listener. Return 0 on success, non-zero otherwise. */ 535 int 536 sclp_register(struct sclp_register *reg) 537 { 538 unsigned long flags; 539 sccb_mask_t receive_mask; 540 sccb_mask_t send_mask; 541 int rc; 542 543 rc = sclp_init(); 544 if (rc) 545 return rc; 546 spin_lock_irqsave(&sclp_lock, flags); 547 /* Check event mask for collisions */ 548 __sclp_get_mask(&receive_mask, &send_mask); 549 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 550 spin_unlock_irqrestore(&sclp_lock, flags); 551 return -EBUSY; 552 } 553 /* Trigger initial state change callback */ 554 reg->sclp_receive_mask = 0; 555 reg->sclp_send_mask = 0; 556 list_add(®->list, &sclp_reg_list); 557 spin_unlock_irqrestore(&sclp_lock, flags); 558 rc = sclp_init_mask(1); 559 if (rc) { 560 spin_lock_irqsave(&sclp_lock, flags); 561 list_del(®->list); 562 spin_unlock_irqrestore(&sclp_lock, flags); 563 } 564 return rc; 565 } 566 567 EXPORT_SYMBOL(sclp_register); 568 569 /* Unregister event listener. */ 570 void 571 sclp_unregister(struct sclp_register *reg) 572 { 573 unsigned long flags; 574 575 spin_lock_irqsave(&sclp_lock, flags); 576 list_del(®->list); 577 spin_unlock_irqrestore(&sclp_lock, flags); 578 sclp_init_mask(1); 579 } 580 581 EXPORT_SYMBOL(sclp_unregister); 582 583 /* Remove event buffers which are marked processed. Return the number of 584 * remaining event buffers. */ 585 int 586 sclp_remove_processed(struct sccb_header *sccb) 587 { 588 struct evbuf_header *evbuf; 589 int unprocessed; 590 u16 remaining; 591 592 evbuf = (struct evbuf_header *) (sccb + 1); 593 unprocessed = 0; 594 remaining = sccb->length - sizeof(struct sccb_header); 595 while (remaining > 0) { 596 remaining -= evbuf->length; 597 if (evbuf->flags & 0x80) { 598 sccb->length -= evbuf->length; 599 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 600 remaining); 601 } else { 602 unprocessed++; 603 evbuf = (struct evbuf_header *) 604 ((addr_t) evbuf + evbuf->length); 605 } 606 } 607 return unprocessed; 608 } 609 610 EXPORT_SYMBOL(sclp_remove_processed); 611 612 struct init_sccb { 613 struct sccb_header header; 614 u16 _reserved; 615 u16 mask_length; 616 sccb_mask_t receive_mask; 617 sccb_mask_t send_mask; 618 sccb_mask_t sclp_send_mask; 619 sccb_mask_t sclp_receive_mask; 620 } __attribute__((packed)); 621 622 /* Prepare init mask request. Called while sclp_lock is locked. */ 623 static inline void 624 __sclp_make_init_req(u32 receive_mask, u32 send_mask) 625 { 626 struct init_sccb *sccb; 627 628 sccb = (struct init_sccb *) sclp_init_sccb; 629 clear_page(sccb); 630 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 631 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 632 sclp_init_req.status = SCLP_REQ_FILLED; 633 sclp_init_req.start_count = 0; 634 sclp_init_req.callback = NULL; 635 sclp_init_req.callback_data = NULL; 636 sclp_init_req.sccb = sccb; 637 sccb->header.length = sizeof(struct init_sccb); 638 sccb->mask_length = sizeof(sccb_mask_t); 639 sccb->receive_mask = receive_mask; 640 sccb->send_mask = send_mask; 641 sccb->sclp_receive_mask = 0; 642 sccb->sclp_send_mask = 0; 643 } 644 645 /* Start init mask request. If calculate is non-zero, calculate the mask as 646 * requested by registered listeners. Use zero mask otherwise. Return 0 on 647 * success, non-zero otherwise. */ 648 static int 649 sclp_init_mask(int calculate) 650 { 651 unsigned long flags; 652 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 653 sccb_mask_t receive_mask; 654 sccb_mask_t send_mask; 655 int retry; 656 int rc; 657 unsigned long wait; 658 659 spin_lock_irqsave(&sclp_lock, flags); 660 /* Check if interface is in appropriate state */ 661 if (sclp_mask_state != sclp_mask_state_idle) { 662 spin_unlock_irqrestore(&sclp_lock, flags); 663 return -EBUSY; 664 } 665 if (sclp_activation_state == sclp_activation_state_inactive) { 666 spin_unlock_irqrestore(&sclp_lock, flags); 667 return -EINVAL; 668 } 669 sclp_mask_state = sclp_mask_state_initializing; 670 /* Determine mask */ 671 if (calculate) 672 __sclp_get_mask(&receive_mask, &send_mask); 673 else { 674 receive_mask = 0; 675 send_mask = 0; 676 } 677 rc = -EIO; 678 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 679 /* Prepare request */ 680 __sclp_make_init_req(receive_mask, send_mask); 681 spin_unlock_irqrestore(&sclp_lock, flags); 682 if (sclp_add_request(&sclp_init_req)) { 683 /* Try again later */ 684 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 685 while (time_before(jiffies, wait)) 686 sclp_sync_wait(); 687 spin_lock_irqsave(&sclp_lock, flags); 688 continue; 689 } 690 while (sclp_init_req.status != SCLP_REQ_DONE && 691 sclp_init_req.status != SCLP_REQ_FAILED) 692 sclp_sync_wait(); 693 spin_lock_irqsave(&sclp_lock, flags); 694 if (sclp_init_req.status == SCLP_REQ_DONE && 695 sccb->header.response_code == 0x20) { 696 /* Successful request */ 697 if (calculate) { 698 sclp_receive_mask = sccb->sclp_receive_mask; 699 sclp_send_mask = sccb->sclp_send_mask; 700 } else { 701 sclp_receive_mask = 0; 702 sclp_send_mask = 0; 703 } 704 spin_unlock_irqrestore(&sclp_lock, flags); 705 sclp_dispatch_state_change(); 706 spin_lock_irqsave(&sclp_lock, flags); 707 rc = 0; 708 break; 709 } 710 } 711 sclp_mask_state = sclp_mask_state_idle; 712 spin_unlock_irqrestore(&sclp_lock, flags); 713 return rc; 714 } 715 716 /* Deactivate SCLP interface. On success, new requests will be rejected, 717 * events will no longer be dispatched. Return 0 on success, non-zero 718 * otherwise. */ 719 int 720 sclp_deactivate(void) 721 { 722 unsigned long flags; 723 int rc; 724 725 spin_lock_irqsave(&sclp_lock, flags); 726 /* Deactivate can only be called when active */ 727 if (sclp_activation_state != sclp_activation_state_active) { 728 spin_unlock_irqrestore(&sclp_lock, flags); 729 return -EINVAL; 730 } 731 sclp_activation_state = sclp_activation_state_deactivating; 732 spin_unlock_irqrestore(&sclp_lock, flags); 733 rc = sclp_init_mask(0); 734 spin_lock_irqsave(&sclp_lock, flags); 735 if (rc == 0) 736 sclp_activation_state = sclp_activation_state_inactive; 737 else 738 sclp_activation_state = sclp_activation_state_active; 739 spin_unlock_irqrestore(&sclp_lock, flags); 740 return rc; 741 } 742 743 EXPORT_SYMBOL(sclp_deactivate); 744 745 /* Reactivate SCLP interface after sclp_deactivate. On success, new 746 * requests will be accepted, events will be dispatched again. Return 0 on 747 * success, non-zero otherwise. */ 748 int 749 sclp_reactivate(void) 750 { 751 unsigned long flags; 752 int rc; 753 754 spin_lock_irqsave(&sclp_lock, flags); 755 /* Reactivate can only be called when inactive */ 756 if (sclp_activation_state != sclp_activation_state_inactive) { 757 spin_unlock_irqrestore(&sclp_lock, flags); 758 return -EINVAL; 759 } 760 sclp_activation_state = sclp_activation_state_activating; 761 spin_unlock_irqrestore(&sclp_lock, flags); 762 rc = sclp_init_mask(1); 763 spin_lock_irqsave(&sclp_lock, flags); 764 if (rc == 0) 765 sclp_activation_state = sclp_activation_state_active; 766 else 767 sclp_activation_state = sclp_activation_state_inactive; 768 spin_unlock_irqrestore(&sclp_lock, flags); 769 return rc; 770 } 771 772 EXPORT_SYMBOL(sclp_reactivate); 773 774 /* Handler for external interruption used during initialization. Modify 775 * request state to done. */ 776 static void 777 sclp_check_handler(__u16 code) 778 { 779 u32 finished_sccb; 780 781 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 782 /* Is this the interrupt we are waiting for? */ 783 if (finished_sccb == 0) 784 return; 785 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) { 786 printk(KERN_WARNING SCLP_HEADER "unsolicited interrupt " 787 "for buffer at 0x%x\n", finished_sccb); 788 return; 789 } 790 spin_lock(&sclp_lock); 791 if (sclp_running_state == sclp_running_state_running) { 792 sclp_init_req.status = SCLP_REQ_DONE; 793 sclp_running_state = sclp_running_state_idle; 794 } 795 spin_unlock(&sclp_lock); 796 } 797 798 /* Initial init mask request timed out. Modify request state to failed. */ 799 static void 800 sclp_check_timeout(unsigned long data) 801 { 802 unsigned long flags; 803 804 spin_lock_irqsave(&sclp_lock, flags); 805 if (sclp_running_state == sclp_running_state_running) { 806 sclp_init_req.status = SCLP_REQ_FAILED; 807 sclp_running_state = sclp_running_state_idle; 808 } 809 spin_unlock_irqrestore(&sclp_lock, flags); 810 } 811 812 /* Perform a check of the SCLP interface. Return zero if the interface is 813 * available and there are no pending requests from a previous instance. 814 * Return non-zero otherwise. */ 815 static int 816 sclp_check_interface(void) 817 { 818 struct init_sccb *sccb; 819 unsigned long flags; 820 int retry; 821 int rc; 822 823 spin_lock_irqsave(&sclp_lock, flags); 824 /* Prepare init mask command */ 825 rc = register_early_external_interrupt(0x2401, sclp_check_handler, 826 &ext_int_info_hwc); 827 if (rc) { 828 spin_unlock_irqrestore(&sclp_lock, flags); 829 return rc; 830 } 831 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 832 __sclp_make_init_req(0, 0); 833 sccb = (struct init_sccb *) sclp_init_req.sccb; 834 rc = sclp_service_call(sclp_init_req.command, sccb); 835 if (rc == -EIO) 836 break; 837 sclp_init_req.status = SCLP_REQ_RUNNING; 838 sclp_running_state = sclp_running_state_running; 839 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 840 sclp_check_timeout, 0); 841 spin_unlock_irqrestore(&sclp_lock, flags); 842 /* Enable service-signal interruption - needs to happen 843 * with IRQs enabled. */ 844 ctl_set_bit(0, 9); 845 /* Wait for signal from interrupt or timeout */ 846 sclp_sync_wait(); 847 /* Disable service-signal interruption - needs to happen 848 * with IRQs enabled. */ 849 ctl_clear_bit(0,9); 850 spin_lock_irqsave(&sclp_lock, flags); 851 del_timer(&sclp_request_timer); 852 if (sclp_init_req.status == SCLP_REQ_DONE && 853 sccb->header.response_code == 0x20) { 854 rc = 0; 855 break; 856 } else 857 rc = -EBUSY; 858 } 859 unregister_early_external_interrupt(0x2401, sclp_check_handler, 860 &ext_int_info_hwc); 861 spin_unlock_irqrestore(&sclp_lock, flags); 862 return rc; 863 } 864 865 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP 866 * events from interfering with rebooted system. */ 867 static int 868 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 869 { 870 sclp_deactivate(); 871 return NOTIFY_DONE; 872 } 873 874 static struct notifier_block sclp_reboot_notifier = { 875 .notifier_call = sclp_reboot_event 876 }; 877 878 /* Initialize SCLP driver. Return zero if driver is operational, non-zero 879 * otherwise. */ 880 static int 881 sclp_init(void) 882 { 883 unsigned long flags; 884 int rc; 885 886 if (!MACHINE_HAS_SCLP) 887 return -ENODEV; 888 spin_lock_irqsave(&sclp_lock, flags); 889 /* Check for previous or running initialization */ 890 if (sclp_init_state != sclp_init_state_uninitialized) { 891 spin_unlock_irqrestore(&sclp_lock, flags); 892 return 0; 893 } 894 sclp_init_state = sclp_init_state_initializing; 895 /* Set up variables */ 896 INIT_LIST_HEAD(&sclp_req_queue); 897 INIT_LIST_HEAD(&sclp_reg_list); 898 list_add(&sclp_state_change_event.list, &sclp_reg_list); 899 init_timer(&sclp_request_timer); 900 /* Check interface */ 901 spin_unlock_irqrestore(&sclp_lock, flags); 902 rc = sclp_check_interface(); 903 spin_lock_irqsave(&sclp_lock, flags); 904 if (rc) { 905 sclp_init_state = sclp_init_state_uninitialized; 906 spin_unlock_irqrestore(&sclp_lock, flags); 907 return rc; 908 } 909 /* Register reboot handler */ 910 rc = register_reboot_notifier(&sclp_reboot_notifier); 911 if (rc) { 912 sclp_init_state = sclp_init_state_uninitialized; 913 spin_unlock_irqrestore(&sclp_lock, flags); 914 return rc; 915 } 916 /* Register interrupt handler */ 917 rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler, 918 &ext_int_info_hwc); 919 if (rc) { 920 unregister_reboot_notifier(&sclp_reboot_notifier); 921 sclp_init_state = sclp_init_state_uninitialized; 922 spin_unlock_irqrestore(&sclp_lock, flags); 923 return rc; 924 } 925 sclp_init_state = sclp_init_state_initialized; 926 spin_unlock_irqrestore(&sclp_lock, flags); 927 /* Enable service-signal external interruption - needs to happen with 928 * IRQs enabled. */ 929 ctl_set_bit(0, 9); 930 sclp_init_mask(1); 931 return 0; 932 } 933