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 = sclp_running_state_idle; 64 65 /* Internal state: is a read request pending? */ 66 static volatile enum sclp_reading_state_t { 67 sclp_reading_state_idle, 68 sclp_reading_state_reading 69 } sclp_reading_state = sclp_reading_state_idle; 70 71 /* Internal state: is the driver currently serving requests? */ 72 static volatile enum sclp_activation_state_t { 73 sclp_activation_state_active, 74 sclp_activation_state_deactivating, 75 sclp_activation_state_inactive, 76 sclp_activation_state_activating 77 } sclp_activation_state = sclp_activation_state_active; 78 79 /* Internal state: is an init mask request pending? */ 80 static volatile enum sclp_mask_state_t { 81 sclp_mask_state_idle, 82 sclp_mask_state_initializing 83 } sclp_mask_state = sclp_mask_state_idle; 84 85 /* Maximum retry counts */ 86 #define SCLP_INIT_RETRY 3 87 #define SCLP_MASK_RETRY 3 88 89 /* Timeout intervals in seconds.*/ 90 #define SCLP_BUSY_INTERVAL 10 91 #define SCLP_RETRY_INTERVAL 15 92 93 static void sclp_process_queue(void); 94 static int sclp_init_mask(int calculate); 95 static int sclp_init(void); 96 97 /* Perform service call. Return 0 on success, non-zero otherwise. */ 98 static int 99 service_call(sclp_cmdw_t command, void *sccb) 100 { 101 int cc; 102 103 __asm__ __volatile__( 104 " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 105 " ipm %0\n" 106 " srl %0,28" 107 : "=&d" (cc) 108 : "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 /* Request timeout handler. Restart the request queue. If DATA is non-zero, 118 * force restart of running request. */ 119 static void 120 sclp_request_timeout(unsigned long data) 121 { 122 unsigned long flags; 123 124 if (data) { 125 spin_lock_irqsave(&sclp_lock, flags); 126 sclp_running_state = sclp_running_state_idle; 127 spin_unlock_irqrestore(&sclp_lock, flags); 128 } 129 sclp_process_queue(); 130 } 131 132 /* Set up request retry timer. Called while sclp_lock is locked. */ 133 static inline void 134 __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), 135 unsigned long data) 136 { 137 del_timer(&sclp_request_timer); 138 sclp_request_timer.function = function; 139 sclp_request_timer.data = data; 140 sclp_request_timer.expires = jiffies + time; 141 add_timer(&sclp_request_timer); 142 } 143 144 /* Try to start a request. Return zero if the request was successfully 145 * started or if it will be started at a later time. Return non-zero otherwise. 146 * Called while sclp_lock is locked. */ 147 static int 148 __sclp_start_request(struct sclp_req *req) 149 { 150 int rc; 151 152 if (sclp_running_state != sclp_running_state_idle) 153 return 0; 154 del_timer(&sclp_request_timer); 155 rc = service_call(req->command, req->sccb); 156 req->start_count++; 157 158 if (rc == 0) { 159 /* Sucessfully started request */ 160 req->status = SCLP_REQ_RUNNING; 161 sclp_running_state = sclp_running_state_running; 162 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 163 sclp_request_timeout, 1); 164 return 0; 165 } else if (rc == -EBUSY) { 166 /* Try again later */ 167 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 168 sclp_request_timeout, 0); 169 return 0; 170 } 171 /* Request failed */ 172 req->status = SCLP_REQ_FAILED; 173 return rc; 174 } 175 176 /* Try to start queued requests. */ 177 static void 178 sclp_process_queue(void) 179 { 180 struct sclp_req *req; 181 int rc; 182 unsigned long flags; 183 184 spin_lock_irqsave(&sclp_lock, flags); 185 if (sclp_running_state != sclp_running_state_idle) { 186 spin_unlock_irqrestore(&sclp_lock, flags); 187 return; 188 } 189 del_timer(&sclp_request_timer); 190 while (!list_empty(&sclp_req_queue)) { 191 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 192 rc = __sclp_start_request(req); 193 if (rc == 0) 194 break; 195 /* Request failed. */ 196 list_del(&req->list); 197 if (req->callback) { 198 spin_unlock_irqrestore(&sclp_lock, flags); 199 req->callback(req, req->callback_data); 200 spin_lock_irqsave(&sclp_lock, flags); 201 } 202 } 203 spin_unlock_irqrestore(&sclp_lock, flags); 204 } 205 206 /* Queue a new request. Return zero on success, non-zero otherwise. */ 207 int 208 sclp_add_request(struct sclp_req *req) 209 { 210 unsigned long flags; 211 int rc; 212 213 spin_lock_irqsave(&sclp_lock, flags); 214 if ((sclp_init_state != sclp_init_state_initialized || 215 sclp_activation_state != sclp_activation_state_active) && 216 req != &sclp_init_req) { 217 spin_unlock_irqrestore(&sclp_lock, flags); 218 return -EIO; 219 } 220 req->status = SCLP_REQ_QUEUED; 221 req->start_count = 0; 222 list_add_tail(&req->list, &sclp_req_queue); 223 rc = 0; 224 /* Start if request is first in list */ 225 if (req->list.prev == &sclp_req_queue) { 226 rc = __sclp_start_request(req); 227 if (rc) 228 list_del(&req->list); 229 } 230 spin_unlock_irqrestore(&sclp_lock, flags); 231 return rc; 232 } 233 234 EXPORT_SYMBOL(sclp_add_request); 235 236 /* Dispatch events found in request buffer to registered listeners. Return 0 237 * if all events were dispatched, non-zero otherwise. */ 238 static int 239 sclp_dispatch_evbufs(struct sccb_header *sccb) 240 { 241 unsigned long flags; 242 struct evbuf_header *evbuf; 243 struct list_head *l; 244 struct sclp_register *reg; 245 int offset; 246 int rc; 247 248 spin_lock_irqsave(&sclp_lock, flags); 249 rc = 0; 250 for (offset = sizeof(struct sccb_header); offset < sccb->length; 251 offset += evbuf->length) { 252 /* Search for event handler */ 253 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 254 reg = NULL; 255 list_for_each(l, &sclp_reg_list) { 256 reg = list_entry(l, struct sclp_register, list); 257 if (reg->receive_mask & (1 << (32 - evbuf->type))) 258 break; 259 else 260 reg = NULL; 261 } 262 if (reg && reg->receiver_fn) { 263 spin_unlock_irqrestore(&sclp_lock, flags); 264 reg->receiver_fn(evbuf); 265 spin_lock_irqsave(&sclp_lock, flags); 266 } else if (reg == NULL) 267 rc = -ENOSYS; 268 } 269 spin_unlock_irqrestore(&sclp_lock, flags); 270 return rc; 271 } 272 273 /* Read event data request callback. */ 274 static void 275 sclp_read_cb(struct sclp_req *req, void *data) 276 { 277 unsigned long flags; 278 struct sccb_header *sccb; 279 280 sccb = (struct sccb_header *) req->sccb; 281 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 282 sccb->response_code == 0x220)) 283 sclp_dispatch_evbufs(sccb); 284 spin_lock_irqsave(&sclp_lock, flags); 285 sclp_reading_state = sclp_reading_state_idle; 286 spin_unlock_irqrestore(&sclp_lock, flags); 287 } 288 289 /* Prepare read event data request. Called while sclp_lock is locked. */ 290 static inline void 291 __sclp_make_read_req(void) 292 { 293 struct sccb_header *sccb; 294 295 sccb = (struct sccb_header *) sclp_read_sccb; 296 clear_page(sccb); 297 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 298 sclp_read_req.command = SCLP_CMDW_READDATA; 299 sclp_read_req.status = SCLP_REQ_QUEUED; 300 sclp_read_req.start_count = 0; 301 sclp_read_req.callback = sclp_read_cb; 302 sclp_read_req.sccb = sccb; 303 sccb->length = PAGE_SIZE; 304 sccb->function_code = 0; 305 sccb->control_mask[2] = 0x80; 306 } 307 308 /* Search request list for request with matching sccb. Return request if found, 309 * NULL otherwise. Called while sclp_lock is locked. */ 310 static inline struct sclp_req * 311 __sclp_find_req(u32 sccb) 312 { 313 struct list_head *l; 314 struct sclp_req *req; 315 316 list_for_each(l, &sclp_req_queue) { 317 req = list_entry(l, struct sclp_req, list); 318 if (sccb == (u32) (addr_t) req->sccb) 319 return req; 320 } 321 return NULL; 322 } 323 324 /* Handler for external interruption. Perform request post-processing. 325 * Prepare read event data request if necessary. Start processing of next 326 * request on queue. */ 327 static void 328 sclp_interrupt_handler(struct pt_regs *regs, __u16 code) 329 { 330 struct sclp_req *req; 331 u32 finished_sccb; 332 u32 evbuf_pending; 333 334 spin_lock(&sclp_lock); 335 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 336 evbuf_pending = S390_lowcore.ext_params & 0x3; 337 if (finished_sccb) { 338 req = __sclp_find_req(finished_sccb); 339 if (req) { 340 /* Request post-processing */ 341 list_del(&req->list); 342 req->status = SCLP_REQ_DONE; 343 if (req->callback) { 344 spin_unlock(&sclp_lock); 345 req->callback(req, req->callback_data); 346 spin_lock(&sclp_lock); 347 } 348 } 349 sclp_running_state = sclp_running_state_idle; 350 } 351 if (evbuf_pending && sclp_receive_mask != 0 && 352 sclp_reading_state == sclp_reading_state_idle && 353 sclp_activation_state == sclp_activation_state_active ) { 354 sclp_reading_state = sclp_reading_state_reading; 355 __sclp_make_read_req(); 356 /* Add request to head of queue */ 357 list_add(&sclp_read_req.list, &sclp_req_queue); 358 } 359 spin_unlock(&sclp_lock); 360 sclp_process_queue(); 361 } 362 363 /* Return current Time-Of-Day clock. */ 364 static inline u64 365 sclp_get_clock(void) 366 { 367 u64 result; 368 369 asm volatile ("STCK 0(%1)" : "=m" (result) : "a" (&(result)) : "cc"); 370 return result; 371 } 372 373 /* Convert interval in jiffies to TOD ticks. */ 374 static inline u64 375 sclp_tod_from_jiffies(unsigned long jiffies) 376 { 377 return (u64) (jiffies / HZ) << 32; 378 } 379 380 /* Wait until a currently running request finished. Note: while this function 381 * is running, no timers are served on the calling CPU. */ 382 void 383 sclp_sync_wait(void) 384 { 385 unsigned long psw_mask; 386 unsigned long flags; 387 unsigned long cr0, cr0_sync; 388 u64 timeout; 389 390 /* We'll be disabling timer interrupts, so we need a custom timeout 391 * mechanism */ 392 timeout = 0; 393 if (timer_pending(&sclp_request_timer)) { 394 /* Get timeout TOD value */ 395 timeout = sclp_get_clock() + 396 sclp_tod_from_jiffies(sclp_request_timer.expires - 397 jiffies); 398 } 399 local_irq_save(flags); 400 /* Prevent bottom half from executing once we force interrupts open */ 401 local_bh_disable(); 402 /* Enable service-signal interruption, disable timer interrupts */ 403 trace_hardirqs_on(); 404 __ctl_store(cr0, 0, 0); 405 cr0_sync = cr0; 406 cr0_sync |= 0x00000200; 407 cr0_sync &= 0xFFFFF3AC; 408 __ctl_load(cr0_sync, 0, 0); 409 asm volatile ("STOSM 0(%1),0x01" 410 : "=m" (psw_mask) : "a" (&psw_mask) : "memory"); 411 /* Loop until driver state indicates finished request */ 412 while (sclp_running_state != sclp_running_state_idle) { 413 /* Check for expired request timer */ 414 if (timer_pending(&sclp_request_timer) && 415 sclp_get_clock() > timeout && 416 del_timer(&sclp_request_timer)) 417 sclp_request_timer.function(sclp_request_timer.data); 418 barrier(); 419 cpu_relax(); 420 } 421 local_irq_disable(); 422 __ctl_load(cr0, 0, 0); 423 _local_bh_enable(); 424 local_irq_restore(flags); 425 } 426 427 EXPORT_SYMBOL(sclp_sync_wait); 428 429 /* Dispatch changes in send and receive mask to registered listeners. */ 430 static inline void 431 sclp_dispatch_state_change(void) 432 { 433 struct list_head *l; 434 struct sclp_register *reg; 435 unsigned long flags; 436 sccb_mask_t receive_mask; 437 sccb_mask_t send_mask; 438 439 do { 440 spin_lock_irqsave(&sclp_lock, flags); 441 reg = NULL; 442 list_for_each(l, &sclp_reg_list) { 443 reg = list_entry(l, struct sclp_register, list); 444 receive_mask = reg->receive_mask & sclp_receive_mask; 445 send_mask = reg->send_mask & sclp_send_mask; 446 if (reg->sclp_receive_mask != receive_mask || 447 reg->sclp_send_mask != send_mask) { 448 reg->sclp_receive_mask = receive_mask; 449 reg->sclp_send_mask = send_mask; 450 break; 451 } else 452 reg = NULL; 453 } 454 spin_unlock_irqrestore(&sclp_lock, flags); 455 if (reg && reg->state_change_fn) 456 reg->state_change_fn(reg); 457 } while (reg); 458 } 459 460 struct sclp_statechangebuf { 461 struct evbuf_header header; 462 u8 validity_sclp_active_facility_mask : 1; 463 u8 validity_sclp_receive_mask : 1; 464 u8 validity_sclp_send_mask : 1; 465 u8 validity_read_data_function_mask : 1; 466 u16 _zeros : 12; 467 u16 mask_length; 468 u64 sclp_active_facility_mask; 469 sccb_mask_t sclp_receive_mask; 470 sccb_mask_t sclp_send_mask; 471 u32 read_data_function_mask; 472 } __attribute__((packed)); 473 474 475 /* State change event callback. Inform listeners of changes. */ 476 static void 477 sclp_state_change_cb(struct evbuf_header *evbuf) 478 { 479 unsigned long flags; 480 struct sclp_statechangebuf *scbuf; 481 482 scbuf = (struct sclp_statechangebuf *) evbuf; 483 if (scbuf->mask_length != sizeof(sccb_mask_t)) 484 return; 485 spin_lock_irqsave(&sclp_lock, flags); 486 if (scbuf->validity_sclp_receive_mask) 487 sclp_receive_mask = scbuf->sclp_receive_mask; 488 if (scbuf->validity_sclp_send_mask) 489 sclp_send_mask = scbuf->sclp_send_mask; 490 spin_unlock_irqrestore(&sclp_lock, flags); 491 sclp_dispatch_state_change(); 492 } 493 494 static struct sclp_register sclp_state_change_event = { 495 .receive_mask = EvTyp_StateChange_Mask, 496 .receiver_fn = sclp_state_change_cb 497 }; 498 499 /* Calculate receive and send mask of currently registered listeners. 500 * Called while sclp_lock is locked. */ 501 static inline void 502 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 503 { 504 struct list_head *l; 505 struct sclp_register *t; 506 507 *receive_mask = 0; 508 *send_mask = 0; 509 list_for_each(l, &sclp_reg_list) { 510 t = list_entry(l, struct sclp_register, list); 511 *receive_mask |= t->receive_mask; 512 *send_mask |= t->send_mask; 513 } 514 } 515 516 /* Register event listener. Return 0 on success, non-zero otherwise. */ 517 int 518 sclp_register(struct sclp_register *reg) 519 { 520 unsigned long flags; 521 sccb_mask_t receive_mask; 522 sccb_mask_t send_mask; 523 int rc; 524 525 rc = sclp_init(); 526 if (rc) 527 return rc; 528 spin_lock_irqsave(&sclp_lock, flags); 529 /* Check event mask for collisions */ 530 __sclp_get_mask(&receive_mask, &send_mask); 531 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 532 spin_unlock_irqrestore(&sclp_lock, flags); 533 return -EBUSY; 534 } 535 /* Trigger initial state change callback */ 536 reg->sclp_receive_mask = 0; 537 reg->sclp_send_mask = 0; 538 list_add(®->list, &sclp_reg_list); 539 spin_unlock_irqrestore(&sclp_lock, flags); 540 rc = sclp_init_mask(1); 541 if (rc) { 542 spin_lock_irqsave(&sclp_lock, flags); 543 list_del(®->list); 544 spin_unlock_irqrestore(&sclp_lock, flags); 545 } 546 return rc; 547 } 548 549 EXPORT_SYMBOL(sclp_register); 550 551 /* Unregister event listener. */ 552 void 553 sclp_unregister(struct sclp_register *reg) 554 { 555 unsigned long flags; 556 557 spin_lock_irqsave(&sclp_lock, flags); 558 list_del(®->list); 559 spin_unlock_irqrestore(&sclp_lock, flags); 560 sclp_init_mask(1); 561 } 562 563 EXPORT_SYMBOL(sclp_unregister); 564 565 /* Remove event buffers which are marked processed. Return the number of 566 * remaining event buffers. */ 567 int 568 sclp_remove_processed(struct sccb_header *sccb) 569 { 570 struct evbuf_header *evbuf; 571 int unprocessed; 572 u16 remaining; 573 574 evbuf = (struct evbuf_header *) (sccb + 1); 575 unprocessed = 0; 576 remaining = sccb->length - sizeof(struct sccb_header); 577 while (remaining > 0) { 578 remaining -= evbuf->length; 579 if (evbuf->flags & 0x80) { 580 sccb->length -= evbuf->length; 581 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 582 remaining); 583 } else { 584 unprocessed++; 585 evbuf = (struct evbuf_header *) 586 ((addr_t) evbuf + evbuf->length); 587 } 588 } 589 return unprocessed; 590 } 591 592 EXPORT_SYMBOL(sclp_remove_processed); 593 594 struct init_sccb { 595 struct sccb_header header; 596 u16 _reserved; 597 u16 mask_length; 598 sccb_mask_t receive_mask; 599 sccb_mask_t send_mask; 600 sccb_mask_t sclp_send_mask; 601 sccb_mask_t sclp_receive_mask; 602 } __attribute__((packed)); 603 604 /* Prepare init mask request. Called while sclp_lock is locked. */ 605 static inline void 606 __sclp_make_init_req(u32 receive_mask, u32 send_mask) 607 { 608 struct init_sccb *sccb; 609 610 sccb = (struct init_sccb *) sclp_init_sccb; 611 clear_page(sccb); 612 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 613 sclp_init_req.command = SCLP_CMDW_WRITEMASK; 614 sclp_init_req.status = SCLP_REQ_FILLED; 615 sclp_init_req.start_count = 0; 616 sclp_init_req.callback = NULL; 617 sclp_init_req.callback_data = NULL; 618 sclp_init_req.sccb = sccb; 619 sccb->header.length = sizeof(struct init_sccb); 620 sccb->mask_length = sizeof(sccb_mask_t); 621 sccb->receive_mask = receive_mask; 622 sccb->send_mask = send_mask; 623 sccb->sclp_receive_mask = 0; 624 sccb->sclp_send_mask = 0; 625 } 626 627 /* Start init mask request. If calculate is non-zero, calculate the mask as 628 * requested by registered listeners. Use zero mask otherwise. Return 0 on 629 * success, non-zero otherwise. */ 630 static int 631 sclp_init_mask(int calculate) 632 { 633 unsigned long flags; 634 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 635 sccb_mask_t receive_mask; 636 sccb_mask_t send_mask; 637 int retry; 638 int rc; 639 unsigned long wait; 640 641 spin_lock_irqsave(&sclp_lock, flags); 642 /* Check if interface is in appropriate state */ 643 if (sclp_mask_state != sclp_mask_state_idle) { 644 spin_unlock_irqrestore(&sclp_lock, flags); 645 return -EBUSY; 646 } 647 if (sclp_activation_state == sclp_activation_state_inactive) { 648 spin_unlock_irqrestore(&sclp_lock, flags); 649 return -EINVAL; 650 } 651 sclp_mask_state = sclp_mask_state_initializing; 652 /* Determine mask */ 653 if (calculate) 654 __sclp_get_mask(&receive_mask, &send_mask); 655 else { 656 receive_mask = 0; 657 send_mask = 0; 658 } 659 rc = -EIO; 660 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 661 /* Prepare request */ 662 __sclp_make_init_req(receive_mask, send_mask); 663 spin_unlock_irqrestore(&sclp_lock, flags); 664 if (sclp_add_request(&sclp_init_req)) { 665 /* Try again later */ 666 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 667 while (time_before(jiffies, wait)) 668 sclp_sync_wait(); 669 spin_lock_irqsave(&sclp_lock, flags); 670 continue; 671 } 672 while (sclp_init_req.status != SCLP_REQ_DONE && 673 sclp_init_req.status != SCLP_REQ_FAILED) 674 sclp_sync_wait(); 675 spin_lock_irqsave(&sclp_lock, flags); 676 if (sclp_init_req.status == SCLP_REQ_DONE && 677 sccb->header.response_code == 0x20) { 678 /* Successful request */ 679 if (calculate) { 680 sclp_receive_mask = sccb->sclp_receive_mask; 681 sclp_send_mask = sccb->sclp_send_mask; 682 } else { 683 sclp_receive_mask = 0; 684 sclp_send_mask = 0; 685 } 686 spin_unlock_irqrestore(&sclp_lock, flags); 687 sclp_dispatch_state_change(); 688 spin_lock_irqsave(&sclp_lock, flags); 689 rc = 0; 690 break; 691 } 692 } 693 sclp_mask_state = sclp_mask_state_idle; 694 spin_unlock_irqrestore(&sclp_lock, flags); 695 return rc; 696 } 697 698 /* Deactivate SCLP interface. On success, new requests will be rejected, 699 * events will no longer be dispatched. Return 0 on success, non-zero 700 * otherwise. */ 701 int 702 sclp_deactivate(void) 703 { 704 unsigned long flags; 705 int rc; 706 707 spin_lock_irqsave(&sclp_lock, flags); 708 /* Deactivate can only be called when active */ 709 if (sclp_activation_state != sclp_activation_state_active) { 710 spin_unlock_irqrestore(&sclp_lock, flags); 711 return -EINVAL; 712 } 713 sclp_activation_state = sclp_activation_state_deactivating; 714 spin_unlock_irqrestore(&sclp_lock, flags); 715 rc = sclp_init_mask(0); 716 spin_lock_irqsave(&sclp_lock, flags); 717 if (rc == 0) 718 sclp_activation_state = sclp_activation_state_inactive; 719 else 720 sclp_activation_state = sclp_activation_state_active; 721 spin_unlock_irqrestore(&sclp_lock, flags); 722 return rc; 723 } 724 725 EXPORT_SYMBOL(sclp_deactivate); 726 727 /* Reactivate SCLP interface after sclp_deactivate. On success, new 728 * requests will be accepted, events will be dispatched again. Return 0 on 729 * success, non-zero otherwise. */ 730 int 731 sclp_reactivate(void) 732 { 733 unsigned long flags; 734 int rc; 735 736 spin_lock_irqsave(&sclp_lock, flags); 737 /* Reactivate can only be called when inactive */ 738 if (sclp_activation_state != sclp_activation_state_inactive) { 739 spin_unlock_irqrestore(&sclp_lock, flags); 740 return -EINVAL; 741 } 742 sclp_activation_state = sclp_activation_state_activating; 743 spin_unlock_irqrestore(&sclp_lock, flags); 744 rc = sclp_init_mask(1); 745 spin_lock_irqsave(&sclp_lock, flags); 746 if (rc == 0) 747 sclp_activation_state = sclp_activation_state_active; 748 else 749 sclp_activation_state = sclp_activation_state_inactive; 750 spin_unlock_irqrestore(&sclp_lock, flags); 751 return rc; 752 } 753 754 EXPORT_SYMBOL(sclp_reactivate); 755 756 /* Handler for external interruption used during initialization. Modify 757 * request state to done. */ 758 static void 759 sclp_check_handler(struct pt_regs *regs, __u16 code) 760 { 761 u32 finished_sccb; 762 763 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 764 /* Is this the interrupt we are waiting for? */ 765 if (finished_sccb == 0) 766 return; 767 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) { 768 printk(KERN_WARNING SCLP_HEADER "unsolicited interrupt " 769 "for buffer at 0x%x\n", finished_sccb); 770 return; 771 } 772 spin_lock(&sclp_lock); 773 if (sclp_running_state == sclp_running_state_running) { 774 sclp_init_req.status = SCLP_REQ_DONE; 775 sclp_running_state = sclp_running_state_idle; 776 } 777 spin_unlock(&sclp_lock); 778 } 779 780 /* Initial init mask request timed out. Modify request state to failed. */ 781 static void 782 sclp_check_timeout(unsigned long data) 783 { 784 unsigned long flags; 785 786 spin_lock_irqsave(&sclp_lock, flags); 787 if (sclp_running_state == sclp_running_state_running) { 788 sclp_init_req.status = SCLP_REQ_FAILED; 789 sclp_running_state = sclp_running_state_idle; 790 } 791 spin_unlock_irqrestore(&sclp_lock, flags); 792 } 793 794 /* Perform a check of the SCLP interface. Return zero if the interface is 795 * available and there are no pending requests from a previous instance. 796 * Return non-zero otherwise. */ 797 static int 798 sclp_check_interface(void) 799 { 800 struct init_sccb *sccb; 801 unsigned long flags; 802 int retry; 803 int rc; 804 805 spin_lock_irqsave(&sclp_lock, flags); 806 /* Prepare init mask command */ 807 rc = register_early_external_interrupt(0x2401, sclp_check_handler, 808 &ext_int_info_hwc); 809 if (rc) { 810 spin_unlock_irqrestore(&sclp_lock, flags); 811 return rc; 812 } 813 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 814 __sclp_make_init_req(0, 0); 815 sccb = (struct init_sccb *) sclp_init_req.sccb; 816 rc = service_call(sclp_init_req.command, sccb); 817 if (rc == -EIO) 818 break; 819 sclp_init_req.status = SCLP_REQ_RUNNING; 820 sclp_running_state = sclp_running_state_running; 821 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 822 sclp_check_timeout, 0); 823 spin_unlock_irqrestore(&sclp_lock, flags); 824 /* Enable service-signal interruption - needs to happen 825 * with IRQs enabled. */ 826 ctl_set_bit(0, 9); 827 /* Wait for signal from interrupt or timeout */ 828 sclp_sync_wait(); 829 /* Disable service-signal interruption - needs to happen 830 * with IRQs enabled. */ 831 ctl_clear_bit(0,9); 832 spin_lock_irqsave(&sclp_lock, flags); 833 del_timer(&sclp_request_timer); 834 if (sclp_init_req.status == SCLP_REQ_DONE && 835 sccb->header.response_code == 0x20) { 836 rc = 0; 837 break; 838 } else 839 rc = -EBUSY; 840 } 841 unregister_early_external_interrupt(0x2401, sclp_check_handler, 842 &ext_int_info_hwc); 843 spin_unlock_irqrestore(&sclp_lock, flags); 844 return rc; 845 } 846 847 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP 848 * events from interfering with rebooted system. */ 849 static int 850 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 851 { 852 sclp_deactivate(); 853 return NOTIFY_DONE; 854 } 855 856 static struct notifier_block sclp_reboot_notifier = { 857 .notifier_call = sclp_reboot_event 858 }; 859 860 /* Initialize SCLP driver. Return zero if driver is operational, non-zero 861 * otherwise. */ 862 static int 863 sclp_init(void) 864 { 865 unsigned long flags; 866 int rc; 867 868 if (!MACHINE_HAS_SCLP) 869 return -ENODEV; 870 spin_lock_irqsave(&sclp_lock, flags); 871 /* Check for previous or running initialization */ 872 if (sclp_init_state != sclp_init_state_uninitialized) { 873 spin_unlock_irqrestore(&sclp_lock, flags); 874 return 0; 875 } 876 sclp_init_state = sclp_init_state_initializing; 877 /* Set up variables */ 878 INIT_LIST_HEAD(&sclp_req_queue); 879 INIT_LIST_HEAD(&sclp_reg_list); 880 list_add(&sclp_state_change_event.list, &sclp_reg_list); 881 init_timer(&sclp_request_timer); 882 /* Check interface */ 883 spin_unlock_irqrestore(&sclp_lock, flags); 884 rc = sclp_check_interface(); 885 spin_lock_irqsave(&sclp_lock, flags); 886 if (rc) { 887 sclp_init_state = sclp_init_state_uninitialized; 888 spin_unlock_irqrestore(&sclp_lock, flags); 889 return rc; 890 } 891 /* Register reboot handler */ 892 rc = register_reboot_notifier(&sclp_reboot_notifier); 893 if (rc) { 894 sclp_init_state = sclp_init_state_uninitialized; 895 spin_unlock_irqrestore(&sclp_lock, flags); 896 return rc; 897 } 898 /* Register interrupt handler */ 899 rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler, 900 &ext_int_info_hwc); 901 if (rc) { 902 unregister_reboot_notifier(&sclp_reboot_notifier); 903 sclp_init_state = sclp_init_state_uninitialized; 904 spin_unlock_irqrestore(&sclp_lock, flags); 905 return rc; 906 } 907 sclp_init_state = sclp_init_state_initialized; 908 spin_unlock_irqrestore(&sclp_lock, flags); 909 /* Enable service-signal external interruption - needs to happen with 910 * IRQs enabled. */ 911 ctl_set_bit(0, 9); 912 sclp_init_mask(1); 913 return 0; 914 } 915