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 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 /* 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 void __sclp_make_read_req(void); 97 static int sclp_init_mask(int calculate); 98 static int sclp_init(void); 99 100 /* Perform service call. Return 0 on success, non-zero otherwise. */ 101 int 102 sclp_service_call(sclp_cmdw_t command, void *sccb) 103 { 104 int cc; 105 106 asm volatile( 107 " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 108 " ipm %0\n" 109 " srl %0,28" 110 : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) 111 : "cc", "memory"); 112 if (cc == 3) 113 return -EIO; 114 if (cc == 2) 115 return -EBUSY; 116 return 0; 117 } 118 119 120 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 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 284 /* Check for malformed hardware response */ 285 if (evbuf->length == 0) 286 break; 287 /* Search for event handler */ 288 reg = NULL; 289 list_for_each(l, &sclp_reg_list) { 290 reg = list_entry(l, struct sclp_register, list); 291 if (reg->receive_mask & (1 << (32 - evbuf->type))) 292 break; 293 else 294 reg = NULL; 295 } 296 if (reg && reg->receiver_fn) { 297 spin_unlock_irqrestore(&sclp_lock, flags); 298 reg->receiver_fn(evbuf); 299 spin_lock_irqsave(&sclp_lock, flags); 300 } else if (reg == NULL) 301 rc = -ENOSYS; 302 } 303 spin_unlock_irqrestore(&sclp_lock, flags); 304 return rc; 305 } 306 307 /* Read event data request callback. */ 308 static void 309 sclp_read_cb(struct sclp_req *req, void *data) 310 { 311 unsigned long flags; 312 struct sccb_header *sccb; 313 314 sccb = (struct sccb_header *) req->sccb; 315 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 316 sccb->response_code == 0x220)) 317 sclp_dispatch_evbufs(sccb); 318 spin_lock_irqsave(&sclp_lock, flags); 319 sclp_reading_state = sclp_reading_state_idle; 320 spin_unlock_irqrestore(&sclp_lock, flags); 321 } 322 323 /* Prepare read event data request. Called while sclp_lock is locked. */ 324 static void __sclp_make_read_req(void) 325 { 326 struct sccb_header *sccb; 327 328 sccb = (struct sccb_header *) sclp_read_sccb; 329 clear_page(sccb); 330 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 331 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 332 sclp_read_req.status = SCLP_REQ_QUEUED; 333 sclp_read_req.start_count = 0; 334 sclp_read_req.callback = sclp_read_cb; 335 sclp_read_req.sccb = sccb; 336 sccb->length = PAGE_SIZE; 337 sccb->function_code = 0; 338 sccb->control_mask[2] = 0x80; 339 } 340 341 /* Search request list for request with matching sccb. Return request if found, 342 * NULL otherwise. Called while sclp_lock is locked. */ 343 static inline struct sclp_req * 344 __sclp_find_req(u32 sccb) 345 { 346 struct list_head *l; 347 struct sclp_req *req; 348 349 list_for_each(l, &sclp_req_queue) { 350 req = list_entry(l, struct sclp_req, list); 351 if (sccb == (u32) (addr_t) req->sccb) 352 return req; 353 } 354 return NULL; 355 } 356 357 /* Handler for external interruption. Perform request post-processing. 358 * Prepare read event data request if necessary. Start processing of next 359 * request on queue. */ 360 static void 361 sclp_interrupt_handler(__u16 code) 362 { 363 struct sclp_req *req; 364 u32 finished_sccb; 365 u32 evbuf_pending; 366 367 spin_lock(&sclp_lock); 368 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 369 evbuf_pending = S390_lowcore.ext_params & 0x3; 370 if (finished_sccb) { 371 del_timer(&sclp_request_timer); 372 sclp_running_state = sclp_running_state_reset_pending; 373 req = __sclp_find_req(finished_sccb); 374 if (req) { 375 /* Request post-processing */ 376 list_del(&req->list); 377 req->status = SCLP_REQ_DONE; 378 if (req->callback) { 379 spin_unlock(&sclp_lock); 380 req->callback(req, req->callback_data); 381 spin_lock(&sclp_lock); 382 } 383 } 384 sclp_running_state = sclp_running_state_idle; 385 } 386 if (evbuf_pending && 387 sclp_activation_state == sclp_activation_state_active) 388 __sclp_queue_read_req(); 389 spin_unlock(&sclp_lock); 390 sclp_process_queue(); 391 } 392 393 /* Convert interval in jiffies to TOD ticks. */ 394 static inline u64 395 sclp_tod_from_jiffies(unsigned long jiffies) 396 { 397 return (u64) (jiffies / HZ) << 32; 398 } 399 400 /* Wait until a currently running request finished. Note: while this function 401 * is running, no timers are served on the calling CPU. */ 402 void 403 sclp_sync_wait(void) 404 { 405 unsigned long long old_tick; 406 unsigned long flags; 407 unsigned long cr0, cr0_sync; 408 u64 timeout; 409 int irq_context; 410 411 /* We'll be disabling timer interrupts, so we need a custom timeout 412 * mechanism */ 413 timeout = 0; 414 if (timer_pending(&sclp_request_timer)) { 415 /* Get timeout TOD value */ 416 timeout = get_clock() + 417 sclp_tod_from_jiffies(sclp_request_timer.expires - 418 jiffies); 419 } 420 local_irq_save(flags); 421 /* Prevent bottom half from executing once we force interrupts open */ 422 irq_context = in_interrupt(); 423 if (!irq_context) 424 local_bh_disable(); 425 /* Enable service-signal interruption, disable timer interrupts */ 426 old_tick = local_tick_disable(); 427 trace_hardirqs_on(); 428 __ctl_store(cr0, 0, 0); 429 cr0_sync = cr0; 430 cr0_sync &= 0xffff00a0; 431 cr0_sync |= 0x00000200; 432 __ctl_load(cr0_sync, 0, 0); 433 __raw_local_irq_stosm(0x01); 434 /* Loop until driver state indicates finished request */ 435 while (sclp_running_state != sclp_running_state_idle) { 436 /* Check for expired request timer */ 437 if (timer_pending(&sclp_request_timer) && 438 get_clock() > timeout && 439 del_timer(&sclp_request_timer)) 440 sclp_request_timer.function(sclp_request_timer.data); 441 cpu_relax(); 442 } 443 local_irq_disable(); 444 __ctl_load(cr0, 0, 0); 445 if (!irq_context) 446 _local_bh_enable(); 447 local_tick_enable(old_tick); 448 local_irq_restore(flags); 449 } 450 EXPORT_SYMBOL(sclp_sync_wait); 451 452 /* Dispatch changes in send and receive mask to registered listeners. */ 453 static void 454 sclp_dispatch_state_change(void) 455 { 456 struct list_head *l; 457 struct sclp_register *reg; 458 unsigned long flags; 459 sccb_mask_t receive_mask; 460 sccb_mask_t send_mask; 461 462 do { 463 spin_lock_irqsave(&sclp_lock, flags); 464 reg = NULL; 465 list_for_each(l, &sclp_reg_list) { 466 reg = list_entry(l, struct sclp_register, list); 467 receive_mask = reg->send_mask & sclp_receive_mask; 468 send_mask = reg->receive_mask & sclp_send_mask; 469 if (reg->sclp_receive_mask != receive_mask || 470 reg->sclp_send_mask != send_mask) { 471 reg->sclp_receive_mask = receive_mask; 472 reg->sclp_send_mask = send_mask; 473 break; 474 } else 475 reg = NULL; 476 } 477 spin_unlock_irqrestore(&sclp_lock, flags); 478 if (reg && reg->state_change_fn) 479 reg->state_change_fn(reg); 480 } while (reg); 481 } 482 483 struct sclp_statechangebuf { 484 struct evbuf_header header; 485 u8 validity_sclp_active_facility_mask : 1; 486 u8 validity_sclp_receive_mask : 1; 487 u8 validity_sclp_send_mask : 1; 488 u8 validity_read_data_function_mask : 1; 489 u16 _zeros : 12; 490 u16 mask_length; 491 u64 sclp_active_facility_mask; 492 sccb_mask_t sclp_receive_mask; 493 sccb_mask_t sclp_send_mask; 494 u32 read_data_function_mask; 495 } __attribute__((packed)); 496 497 498 /* State change event callback. Inform listeners of changes. */ 499 static void 500 sclp_state_change_cb(struct evbuf_header *evbuf) 501 { 502 unsigned long flags; 503 struct sclp_statechangebuf *scbuf; 504 505 scbuf = (struct sclp_statechangebuf *) evbuf; 506 if (scbuf->mask_length != sizeof(sccb_mask_t)) 507 return; 508 spin_lock_irqsave(&sclp_lock, flags); 509 if (scbuf->validity_sclp_receive_mask) 510 sclp_receive_mask = scbuf->sclp_receive_mask; 511 if (scbuf->validity_sclp_send_mask) 512 sclp_send_mask = scbuf->sclp_send_mask; 513 spin_unlock_irqrestore(&sclp_lock, flags); 514 if (scbuf->validity_sclp_active_facility_mask) 515 sclp_facilities = scbuf->sclp_active_facility_mask; 516 sclp_dispatch_state_change(); 517 } 518 519 static struct sclp_register sclp_state_change_event = { 520 .receive_mask = EVTYP_STATECHANGE_MASK, 521 .receiver_fn = sclp_state_change_cb 522 }; 523 524 /* Calculate receive and send mask of currently registered listeners. 525 * Called while sclp_lock is locked. */ 526 static inline void 527 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 528 { 529 struct list_head *l; 530 struct sclp_register *t; 531 532 *receive_mask = 0; 533 *send_mask = 0; 534 list_for_each(l, &sclp_reg_list) { 535 t = list_entry(l, struct sclp_register, list); 536 *receive_mask |= t->receive_mask; 537 *send_mask |= t->send_mask; 538 } 539 } 540 541 /* Register event listener. Return 0 on success, non-zero otherwise. */ 542 int 543 sclp_register(struct sclp_register *reg) 544 { 545 unsigned long flags; 546 sccb_mask_t receive_mask; 547 sccb_mask_t send_mask; 548 int rc; 549 550 rc = sclp_init(); 551 if (rc) 552 return rc; 553 spin_lock_irqsave(&sclp_lock, flags); 554 /* Check event mask for collisions */ 555 __sclp_get_mask(&receive_mask, &send_mask); 556 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 557 spin_unlock_irqrestore(&sclp_lock, flags); 558 return -EBUSY; 559 } 560 /* Trigger initial state change callback */ 561 reg->sclp_receive_mask = 0; 562 reg->sclp_send_mask = 0; 563 list_add(®->list, &sclp_reg_list); 564 spin_unlock_irqrestore(&sclp_lock, flags); 565 rc = sclp_init_mask(1); 566 if (rc) { 567 spin_lock_irqsave(&sclp_lock, flags); 568 list_del(®->list); 569 spin_unlock_irqrestore(&sclp_lock, flags); 570 } 571 return rc; 572 } 573 574 EXPORT_SYMBOL(sclp_register); 575 576 /* Unregister event listener. */ 577 void 578 sclp_unregister(struct sclp_register *reg) 579 { 580 unsigned long flags; 581 582 spin_lock_irqsave(&sclp_lock, flags); 583 list_del(®->list); 584 spin_unlock_irqrestore(&sclp_lock, flags); 585 sclp_init_mask(1); 586 } 587 588 EXPORT_SYMBOL(sclp_unregister); 589 590 /* Remove event buffers which are marked processed. Return the number of 591 * remaining event buffers. */ 592 int 593 sclp_remove_processed(struct sccb_header *sccb) 594 { 595 struct evbuf_header *evbuf; 596 int unprocessed; 597 u16 remaining; 598 599 evbuf = (struct evbuf_header *) (sccb + 1); 600 unprocessed = 0; 601 remaining = sccb->length - sizeof(struct sccb_header); 602 while (remaining > 0) { 603 remaining -= evbuf->length; 604 if (evbuf->flags & 0x80) { 605 sccb->length -= evbuf->length; 606 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 607 remaining); 608 } else { 609 unprocessed++; 610 evbuf = (struct evbuf_header *) 611 ((addr_t) evbuf + evbuf->length); 612 } 613 } 614 return unprocessed; 615 } 616 617 EXPORT_SYMBOL(sclp_remove_processed); 618 619 struct init_sccb { 620 struct sccb_header header; 621 u16 _reserved; 622 u16 mask_length; 623 sccb_mask_t receive_mask; 624 sccb_mask_t send_mask; 625 sccb_mask_t sclp_receive_mask; 626 sccb_mask_t sclp_send_mask; 627 } __attribute__((packed)); 628 629 /* Prepare init mask request. Called while sclp_lock is locked. */ 630 static inline void 631 __sclp_make_init_req(u32 receive_mask, u32 send_mask) 632 { 633 struct init_sccb *sccb; 634 635 sccb = (struct init_sccb *) sclp_init_sccb; 636 clear_page(sccb); 637 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 638 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 639 sclp_init_req.status = SCLP_REQ_FILLED; 640 sclp_init_req.start_count = 0; 641 sclp_init_req.callback = NULL; 642 sclp_init_req.callback_data = NULL; 643 sclp_init_req.sccb = sccb; 644 sccb->header.length = sizeof(struct init_sccb); 645 sccb->mask_length = sizeof(sccb_mask_t); 646 sccb->receive_mask = receive_mask; 647 sccb->send_mask = send_mask; 648 sccb->sclp_receive_mask = 0; 649 sccb->sclp_send_mask = 0; 650 } 651 652 /* Start init mask request. If calculate is non-zero, calculate the mask as 653 * requested by registered listeners. Use zero mask otherwise. Return 0 on 654 * success, non-zero otherwise. */ 655 static int 656 sclp_init_mask(int calculate) 657 { 658 unsigned long flags; 659 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 660 sccb_mask_t receive_mask; 661 sccb_mask_t send_mask; 662 int retry; 663 int rc; 664 unsigned long wait; 665 666 spin_lock_irqsave(&sclp_lock, flags); 667 /* Check if interface is in appropriate state */ 668 if (sclp_mask_state != sclp_mask_state_idle) { 669 spin_unlock_irqrestore(&sclp_lock, flags); 670 return -EBUSY; 671 } 672 if (sclp_activation_state == sclp_activation_state_inactive) { 673 spin_unlock_irqrestore(&sclp_lock, flags); 674 return -EINVAL; 675 } 676 sclp_mask_state = sclp_mask_state_initializing; 677 /* Determine mask */ 678 if (calculate) 679 __sclp_get_mask(&receive_mask, &send_mask); 680 else { 681 receive_mask = 0; 682 send_mask = 0; 683 } 684 rc = -EIO; 685 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 686 /* Prepare request */ 687 __sclp_make_init_req(receive_mask, send_mask); 688 spin_unlock_irqrestore(&sclp_lock, flags); 689 if (sclp_add_request(&sclp_init_req)) { 690 /* Try again later */ 691 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 692 while (time_before(jiffies, wait)) 693 sclp_sync_wait(); 694 spin_lock_irqsave(&sclp_lock, flags); 695 continue; 696 } 697 while (sclp_init_req.status != SCLP_REQ_DONE && 698 sclp_init_req.status != SCLP_REQ_FAILED) 699 sclp_sync_wait(); 700 spin_lock_irqsave(&sclp_lock, flags); 701 if (sclp_init_req.status == SCLP_REQ_DONE && 702 sccb->header.response_code == 0x20) { 703 /* Successful request */ 704 if (calculate) { 705 sclp_receive_mask = sccb->sclp_receive_mask; 706 sclp_send_mask = sccb->sclp_send_mask; 707 } else { 708 sclp_receive_mask = 0; 709 sclp_send_mask = 0; 710 } 711 spin_unlock_irqrestore(&sclp_lock, flags); 712 sclp_dispatch_state_change(); 713 spin_lock_irqsave(&sclp_lock, flags); 714 rc = 0; 715 break; 716 } 717 } 718 sclp_mask_state = sclp_mask_state_idle; 719 spin_unlock_irqrestore(&sclp_lock, flags); 720 return rc; 721 } 722 723 /* Deactivate SCLP interface. On success, new requests will be rejected, 724 * events will no longer be dispatched. Return 0 on success, non-zero 725 * otherwise. */ 726 int 727 sclp_deactivate(void) 728 { 729 unsigned long flags; 730 int rc; 731 732 spin_lock_irqsave(&sclp_lock, flags); 733 /* Deactivate can only be called when active */ 734 if (sclp_activation_state != sclp_activation_state_active) { 735 spin_unlock_irqrestore(&sclp_lock, flags); 736 return -EINVAL; 737 } 738 sclp_activation_state = sclp_activation_state_deactivating; 739 spin_unlock_irqrestore(&sclp_lock, flags); 740 rc = sclp_init_mask(0); 741 spin_lock_irqsave(&sclp_lock, flags); 742 if (rc == 0) 743 sclp_activation_state = sclp_activation_state_inactive; 744 else 745 sclp_activation_state = sclp_activation_state_active; 746 spin_unlock_irqrestore(&sclp_lock, flags); 747 return rc; 748 } 749 750 EXPORT_SYMBOL(sclp_deactivate); 751 752 /* Reactivate SCLP interface after sclp_deactivate. On success, new 753 * requests will be accepted, events will be dispatched again. Return 0 on 754 * success, non-zero otherwise. */ 755 int 756 sclp_reactivate(void) 757 { 758 unsigned long flags; 759 int rc; 760 761 spin_lock_irqsave(&sclp_lock, flags); 762 /* Reactivate can only be called when inactive */ 763 if (sclp_activation_state != sclp_activation_state_inactive) { 764 spin_unlock_irqrestore(&sclp_lock, flags); 765 return -EINVAL; 766 } 767 sclp_activation_state = sclp_activation_state_activating; 768 spin_unlock_irqrestore(&sclp_lock, flags); 769 rc = sclp_init_mask(1); 770 spin_lock_irqsave(&sclp_lock, flags); 771 if (rc == 0) 772 sclp_activation_state = sclp_activation_state_active; 773 else 774 sclp_activation_state = sclp_activation_state_inactive; 775 spin_unlock_irqrestore(&sclp_lock, flags); 776 return rc; 777 } 778 779 EXPORT_SYMBOL(sclp_reactivate); 780 781 /* Handler for external interruption used during initialization. Modify 782 * request state to done. */ 783 static void 784 sclp_check_handler(__u16 code) 785 { 786 u32 finished_sccb; 787 788 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 789 /* Is this the interrupt we are waiting for? */ 790 if (finished_sccb == 0) 791 return; 792 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) 793 panic("sclp: unsolicited interrupt for buffer at 0x%x\n", 794 finished_sccb); 795 spin_lock(&sclp_lock); 796 if (sclp_running_state == sclp_running_state_running) { 797 sclp_init_req.status = SCLP_REQ_DONE; 798 sclp_running_state = sclp_running_state_idle; 799 } 800 spin_unlock(&sclp_lock); 801 } 802 803 /* Initial init mask request timed out. Modify request state to failed. */ 804 static void 805 sclp_check_timeout(unsigned long data) 806 { 807 unsigned long flags; 808 809 spin_lock_irqsave(&sclp_lock, flags); 810 if (sclp_running_state == sclp_running_state_running) { 811 sclp_init_req.status = SCLP_REQ_FAILED; 812 sclp_running_state = sclp_running_state_idle; 813 } 814 spin_unlock_irqrestore(&sclp_lock, flags); 815 } 816 817 /* Perform a check of the SCLP interface. Return zero if the interface is 818 * available and there are no pending requests from a previous instance. 819 * Return non-zero otherwise. */ 820 static int 821 sclp_check_interface(void) 822 { 823 struct init_sccb *sccb; 824 unsigned long flags; 825 int retry; 826 int rc; 827 828 spin_lock_irqsave(&sclp_lock, flags); 829 /* Prepare init mask command */ 830 rc = register_early_external_interrupt(0x2401, sclp_check_handler, 831 &ext_int_info_hwc); 832 if (rc) { 833 spin_unlock_irqrestore(&sclp_lock, flags); 834 return rc; 835 } 836 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 837 __sclp_make_init_req(0, 0); 838 sccb = (struct init_sccb *) sclp_init_req.sccb; 839 rc = sclp_service_call(sclp_init_req.command, sccb); 840 if (rc == -EIO) 841 break; 842 sclp_init_req.status = SCLP_REQ_RUNNING; 843 sclp_running_state = sclp_running_state_running; 844 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 845 sclp_check_timeout, 0); 846 spin_unlock_irqrestore(&sclp_lock, flags); 847 /* Enable service-signal interruption - needs to happen 848 * with IRQs enabled. */ 849 ctl_set_bit(0, 9); 850 /* Wait for signal from interrupt or timeout */ 851 sclp_sync_wait(); 852 /* Disable service-signal interruption - needs to happen 853 * with IRQs enabled. */ 854 ctl_clear_bit(0,9); 855 spin_lock_irqsave(&sclp_lock, flags); 856 del_timer(&sclp_request_timer); 857 if (sclp_init_req.status == SCLP_REQ_DONE && 858 sccb->header.response_code == 0x20) { 859 rc = 0; 860 break; 861 } else 862 rc = -EBUSY; 863 } 864 unregister_early_external_interrupt(0x2401, sclp_check_handler, 865 &ext_int_info_hwc); 866 spin_unlock_irqrestore(&sclp_lock, flags); 867 return rc; 868 } 869 870 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP 871 * events from interfering with rebooted system. */ 872 static int 873 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 874 { 875 sclp_deactivate(); 876 return NOTIFY_DONE; 877 } 878 879 static struct notifier_block sclp_reboot_notifier = { 880 .notifier_call = sclp_reboot_event 881 }; 882 883 /* Initialize SCLP driver. Return zero if driver is operational, non-zero 884 * otherwise. */ 885 static int 886 sclp_init(void) 887 { 888 unsigned long flags; 889 int rc; 890 891 spin_lock_irqsave(&sclp_lock, flags); 892 /* Check for previous or running initialization */ 893 if (sclp_init_state != sclp_init_state_uninitialized) { 894 spin_unlock_irqrestore(&sclp_lock, flags); 895 return 0; 896 } 897 sclp_init_state = sclp_init_state_initializing; 898 /* Set up variables */ 899 INIT_LIST_HEAD(&sclp_req_queue); 900 INIT_LIST_HEAD(&sclp_reg_list); 901 list_add(&sclp_state_change_event.list, &sclp_reg_list); 902 init_timer(&sclp_request_timer); 903 /* Check interface */ 904 spin_unlock_irqrestore(&sclp_lock, flags); 905 rc = sclp_check_interface(); 906 spin_lock_irqsave(&sclp_lock, flags); 907 if (rc) { 908 sclp_init_state = sclp_init_state_uninitialized; 909 spin_unlock_irqrestore(&sclp_lock, flags); 910 return rc; 911 } 912 /* Register reboot handler */ 913 rc = register_reboot_notifier(&sclp_reboot_notifier); 914 if (rc) { 915 sclp_init_state = sclp_init_state_uninitialized; 916 spin_unlock_irqrestore(&sclp_lock, flags); 917 return rc; 918 } 919 /* Register interrupt handler */ 920 rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler, 921 &ext_int_info_hwc); 922 if (rc) { 923 unregister_reboot_notifier(&sclp_reboot_notifier); 924 sclp_init_state = sclp_init_state_uninitialized; 925 spin_unlock_irqrestore(&sclp_lock, flags); 926 return rc; 927 } 928 sclp_init_state = sclp_init_state_initialized; 929 spin_unlock_irqrestore(&sclp_lock, flags); 930 /* Enable service-signal external interruption - needs to happen with 931 * IRQs enabled. */ 932 ctl_set_bit(0, 9); 933 sclp_init_mask(1); 934 return 0; 935 } 936 937 static __init int sclp_initcall(void) 938 { 939 return sclp_init(); 940 } 941 942 arch_initcall(sclp_initcall); 943