1 /* 2 * core function to access sclp interface 3 * 4 * Copyright IBM Corp. 1999, 2009 5 * 6 * Author(s): Martin Peschke <mpeschke@de.ibm.com> 7 * Martin Schwidefsky <schwidefsky@de.ibm.com> 8 */ 9 10 #include <linux/kernel_stat.h> 11 #include <linux/module.h> 12 #include <linux/err.h> 13 #include <linux/spinlock.h> 14 #include <linux/interrupt.h> 15 #include <linux/timer.h> 16 #include <linux/reboot.h> 17 #include <linux/jiffies.h> 18 #include <linux/init.h> 19 #include <linux/suspend.h> 20 #include <linux/completion.h> 21 #include <linux/platform_device.h> 22 #include <asm/types.h> 23 #include <asm/irq.h> 24 25 #include "sclp.h" 26 27 #define SCLP_HEADER "sclp: " 28 29 /* Lock to protect internal data consistency. */ 30 static DEFINE_SPINLOCK(sclp_lock); 31 32 /* Mask of events that we can send to the sclp interface. */ 33 static sccb_mask_t sclp_receive_mask; 34 35 /* Mask of events that we can receive from the sclp interface. */ 36 static sccb_mask_t sclp_send_mask; 37 38 /* List of registered event listeners and senders. */ 39 static struct list_head sclp_reg_list; 40 41 /* List of queued requests. */ 42 static struct list_head sclp_req_queue; 43 44 /* Data for read and and init requests. */ 45 static struct sclp_req sclp_read_req; 46 static struct sclp_req sclp_init_req; 47 static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 48 static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 49 50 /* Suspend request */ 51 static DECLARE_COMPLETION(sclp_request_queue_flushed); 52 53 static void sclp_suspend_req_cb(struct sclp_req *req, void *data) 54 { 55 complete(&sclp_request_queue_flushed); 56 } 57 58 static struct sclp_req sclp_suspend_req; 59 60 /* Timer for request retries. */ 61 static struct timer_list sclp_request_timer; 62 63 /* Internal state: is the driver initialized? */ 64 static volatile enum sclp_init_state_t { 65 sclp_init_state_uninitialized, 66 sclp_init_state_initializing, 67 sclp_init_state_initialized 68 } sclp_init_state = sclp_init_state_uninitialized; 69 70 /* Internal state: is a request active at the sclp? */ 71 static volatile enum sclp_running_state_t { 72 sclp_running_state_idle, 73 sclp_running_state_running, 74 sclp_running_state_reset_pending 75 } sclp_running_state = sclp_running_state_idle; 76 77 /* Internal state: is a read request pending? */ 78 static volatile enum sclp_reading_state_t { 79 sclp_reading_state_idle, 80 sclp_reading_state_reading 81 } sclp_reading_state = sclp_reading_state_idle; 82 83 /* Internal state: is the driver currently serving requests? */ 84 static volatile enum sclp_activation_state_t { 85 sclp_activation_state_active, 86 sclp_activation_state_deactivating, 87 sclp_activation_state_inactive, 88 sclp_activation_state_activating 89 } sclp_activation_state = sclp_activation_state_active; 90 91 /* Internal state: is an init mask request pending? */ 92 static volatile enum sclp_mask_state_t { 93 sclp_mask_state_idle, 94 sclp_mask_state_initializing 95 } sclp_mask_state = sclp_mask_state_idle; 96 97 /* Internal state: is the driver suspended? */ 98 static enum sclp_suspend_state_t { 99 sclp_suspend_state_running, 100 sclp_suspend_state_suspended, 101 } sclp_suspend_state = sclp_suspend_state_running; 102 103 /* Maximum retry counts */ 104 #define SCLP_INIT_RETRY 3 105 #define SCLP_MASK_RETRY 3 106 107 /* Timeout intervals in seconds.*/ 108 #define SCLP_BUSY_INTERVAL 10 109 #define SCLP_RETRY_INTERVAL 30 110 111 static void sclp_process_queue(void); 112 static void __sclp_make_read_req(void); 113 static int sclp_init_mask(int calculate); 114 static int sclp_init(void); 115 116 /* Perform service call. Return 0 on success, non-zero otherwise. */ 117 int 118 sclp_service_call(sclp_cmdw_t command, void *sccb) 119 { 120 int cc; 121 122 asm volatile( 123 " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 124 " ipm %0\n" 125 " srl %0,28" 126 : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) 127 : "cc", "memory"); 128 if (cc == 3) 129 return -EIO; 130 if (cc == 2) 131 return -EBUSY; 132 return 0; 133 } 134 135 136 static void 137 __sclp_queue_read_req(void) 138 { 139 if (sclp_reading_state == sclp_reading_state_idle) { 140 sclp_reading_state = sclp_reading_state_reading; 141 __sclp_make_read_req(); 142 /* Add request to head of queue */ 143 list_add(&sclp_read_req.list, &sclp_req_queue); 144 } 145 } 146 147 /* Set up request retry timer. Called while sclp_lock is locked. */ 148 static inline void 149 __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), 150 unsigned long data) 151 { 152 del_timer(&sclp_request_timer); 153 sclp_request_timer.function = function; 154 sclp_request_timer.data = data; 155 sclp_request_timer.expires = jiffies + time; 156 add_timer(&sclp_request_timer); 157 } 158 159 /* Request timeout handler. Restart the request queue. If DATA is non-zero, 160 * force restart of running request. */ 161 static void 162 sclp_request_timeout(unsigned long data) 163 { 164 unsigned long flags; 165 166 spin_lock_irqsave(&sclp_lock, flags); 167 if (data) { 168 if (sclp_running_state == sclp_running_state_running) { 169 /* Break running state and queue NOP read event request 170 * to get a defined interface state. */ 171 __sclp_queue_read_req(); 172 sclp_running_state = sclp_running_state_idle; 173 } 174 } else { 175 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 176 sclp_request_timeout, 0); 177 } 178 spin_unlock_irqrestore(&sclp_lock, flags); 179 sclp_process_queue(); 180 } 181 182 /* Try to start a request. Return zero if the request was successfully 183 * started or if it will be started at a later time. Return non-zero otherwise. 184 * Called while sclp_lock is locked. */ 185 static int 186 __sclp_start_request(struct sclp_req *req) 187 { 188 int rc; 189 190 if (sclp_running_state != sclp_running_state_idle) 191 return 0; 192 del_timer(&sclp_request_timer); 193 rc = sclp_service_call(req->command, req->sccb); 194 req->start_count++; 195 196 if (rc == 0) { 197 /* Successfully started request */ 198 req->status = SCLP_REQ_RUNNING; 199 sclp_running_state = sclp_running_state_running; 200 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 201 sclp_request_timeout, 1); 202 return 0; 203 } else if (rc == -EBUSY) { 204 /* Try again later */ 205 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 206 sclp_request_timeout, 0); 207 return 0; 208 } 209 /* Request failed */ 210 req->status = SCLP_REQ_FAILED; 211 return rc; 212 } 213 214 /* Try to start queued requests. */ 215 static void 216 sclp_process_queue(void) 217 { 218 struct sclp_req *req; 219 int rc; 220 unsigned long flags; 221 222 spin_lock_irqsave(&sclp_lock, flags); 223 if (sclp_running_state != sclp_running_state_idle) { 224 spin_unlock_irqrestore(&sclp_lock, flags); 225 return; 226 } 227 del_timer(&sclp_request_timer); 228 while (!list_empty(&sclp_req_queue)) { 229 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 230 if (!req->sccb) 231 goto do_post; 232 rc = __sclp_start_request(req); 233 if (rc == 0) 234 break; 235 /* Request failed */ 236 if (req->start_count > 1) { 237 /* Cannot abort already submitted request - could still 238 * be active at the SCLP */ 239 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 240 sclp_request_timeout, 0); 241 break; 242 } 243 do_post: 244 /* Post-processing for aborted request */ 245 list_del(&req->list); 246 if (req->callback) { 247 spin_unlock_irqrestore(&sclp_lock, flags); 248 req->callback(req, req->callback_data); 249 spin_lock_irqsave(&sclp_lock, flags); 250 } 251 } 252 spin_unlock_irqrestore(&sclp_lock, flags); 253 } 254 255 static int __sclp_can_add_request(struct sclp_req *req) 256 { 257 if (req == &sclp_suspend_req || req == &sclp_init_req) 258 return 1; 259 if (sclp_suspend_state != sclp_suspend_state_running) 260 return 0; 261 if (sclp_init_state != sclp_init_state_initialized) 262 return 0; 263 if (sclp_activation_state != sclp_activation_state_active) 264 return 0; 265 return 1; 266 } 267 268 /* Queue a new request. Return zero on success, non-zero otherwise. */ 269 int 270 sclp_add_request(struct sclp_req *req) 271 { 272 unsigned long flags; 273 int rc; 274 275 spin_lock_irqsave(&sclp_lock, flags); 276 if (!__sclp_can_add_request(req)) { 277 spin_unlock_irqrestore(&sclp_lock, flags); 278 return -EIO; 279 } 280 req->status = SCLP_REQ_QUEUED; 281 req->start_count = 0; 282 list_add_tail(&req->list, &sclp_req_queue); 283 rc = 0; 284 /* Start if request is first in list */ 285 if (sclp_running_state == sclp_running_state_idle && 286 req->list.prev == &sclp_req_queue) { 287 if (!req->sccb) { 288 list_del(&req->list); 289 rc = -ENODATA; 290 goto out; 291 } 292 rc = __sclp_start_request(req); 293 if (rc) 294 list_del(&req->list); 295 } 296 out: 297 spin_unlock_irqrestore(&sclp_lock, flags); 298 return rc; 299 } 300 301 EXPORT_SYMBOL(sclp_add_request); 302 303 /* Dispatch events found in request buffer to registered listeners. Return 0 304 * if all events were dispatched, non-zero otherwise. */ 305 static int 306 sclp_dispatch_evbufs(struct sccb_header *sccb) 307 { 308 unsigned long flags; 309 struct evbuf_header *evbuf; 310 struct list_head *l; 311 struct sclp_register *reg; 312 int offset; 313 int rc; 314 315 spin_lock_irqsave(&sclp_lock, flags); 316 rc = 0; 317 for (offset = sizeof(struct sccb_header); offset < sccb->length; 318 offset += evbuf->length) { 319 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 320 /* Check for malformed hardware response */ 321 if (evbuf->length == 0) 322 break; 323 /* Search for event handler */ 324 reg = NULL; 325 list_for_each(l, &sclp_reg_list) { 326 reg = list_entry(l, struct sclp_register, list); 327 if (reg->receive_mask & (1 << (32 - evbuf->type))) 328 break; 329 else 330 reg = NULL; 331 } 332 if (reg && reg->receiver_fn) { 333 spin_unlock_irqrestore(&sclp_lock, flags); 334 reg->receiver_fn(evbuf); 335 spin_lock_irqsave(&sclp_lock, flags); 336 } else if (reg == NULL) 337 rc = -ENOSYS; 338 } 339 spin_unlock_irqrestore(&sclp_lock, flags); 340 return rc; 341 } 342 343 /* Read event data request callback. */ 344 static void 345 sclp_read_cb(struct sclp_req *req, void *data) 346 { 347 unsigned long flags; 348 struct sccb_header *sccb; 349 350 sccb = (struct sccb_header *) req->sccb; 351 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 352 sccb->response_code == 0x220)) 353 sclp_dispatch_evbufs(sccb); 354 spin_lock_irqsave(&sclp_lock, flags); 355 sclp_reading_state = sclp_reading_state_idle; 356 spin_unlock_irqrestore(&sclp_lock, flags); 357 } 358 359 /* Prepare read event data request. Called while sclp_lock is locked. */ 360 static void __sclp_make_read_req(void) 361 { 362 struct sccb_header *sccb; 363 364 sccb = (struct sccb_header *) sclp_read_sccb; 365 clear_page(sccb); 366 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 367 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 368 sclp_read_req.status = SCLP_REQ_QUEUED; 369 sclp_read_req.start_count = 0; 370 sclp_read_req.callback = sclp_read_cb; 371 sclp_read_req.sccb = sccb; 372 sccb->length = PAGE_SIZE; 373 sccb->function_code = 0; 374 sccb->control_mask[2] = 0x80; 375 } 376 377 /* Search request list for request with matching sccb. Return request if found, 378 * NULL otherwise. Called while sclp_lock is locked. */ 379 static inline struct sclp_req * 380 __sclp_find_req(u32 sccb) 381 { 382 struct list_head *l; 383 struct sclp_req *req; 384 385 list_for_each(l, &sclp_req_queue) { 386 req = list_entry(l, struct sclp_req, list); 387 if (sccb == (u32) (addr_t) req->sccb) 388 return req; 389 } 390 return NULL; 391 } 392 393 /* Handler for external interruption. Perform request post-processing. 394 * Prepare read event data request if necessary. Start processing of next 395 * request on queue. */ 396 static void sclp_interrupt_handler(struct ext_code ext_code, 397 unsigned int param32, unsigned long param64) 398 { 399 struct sclp_req *req; 400 u32 finished_sccb; 401 u32 evbuf_pending; 402 403 kstat_cpu(smp_processor_id()).irqs[EXTINT_SCP]++; 404 spin_lock(&sclp_lock); 405 finished_sccb = param32 & 0xfffffff8; 406 evbuf_pending = param32 & 0x3; 407 if (finished_sccb) { 408 del_timer(&sclp_request_timer); 409 sclp_running_state = sclp_running_state_reset_pending; 410 req = __sclp_find_req(finished_sccb); 411 if (req) { 412 /* Request post-processing */ 413 list_del(&req->list); 414 req->status = SCLP_REQ_DONE; 415 if (req->callback) { 416 spin_unlock(&sclp_lock); 417 req->callback(req, req->callback_data); 418 spin_lock(&sclp_lock); 419 } 420 } 421 sclp_running_state = sclp_running_state_idle; 422 } 423 if (evbuf_pending && 424 sclp_activation_state == sclp_activation_state_active) 425 __sclp_queue_read_req(); 426 spin_unlock(&sclp_lock); 427 sclp_process_queue(); 428 } 429 430 /* Convert interval in jiffies to TOD ticks. */ 431 static inline u64 432 sclp_tod_from_jiffies(unsigned long jiffies) 433 { 434 return (u64) (jiffies / HZ) << 32; 435 } 436 437 /* Wait until a currently running request finished. Note: while this function 438 * is running, no timers are served on the calling CPU. */ 439 void 440 sclp_sync_wait(void) 441 { 442 unsigned long long old_tick; 443 unsigned long flags; 444 unsigned long cr0, cr0_sync; 445 u64 timeout; 446 int irq_context; 447 448 /* We'll be disabling timer interrupts, so we need a custom timeout 449 * mechanism */ 450 timeout = 0; 451 if (timer_pending(&sclp_request_timer)) { 452 /* Get timeout TOD value */ 453 timeout = get_clock() + 454 sclp_tod_from_jiffies(sclp_request_timer.expires - 455 jiffies); 456 } 457 local_irq_save(flags); 458 /* Prevent bottom half from executing once we force interrupts open */ 459 irq_context = in_interrupt(); 460 if (!irq_context) 461 local_bh_disable(); 462 /* Enable service-signal interruption, disable timer interrupts */ 463 old_tick = local_tick_disable(); 464 trace_hardirqs_on(); 465 __ctl_store(cr0, 0, 0); 466 cr0_sync = cr0; 467 cr0_sync &= 0xffff00a0; 468 cr0_sync |= 0x00000200; 469 __ctl_load(cr0_sync, 0, 0); 470 __arch_local_irq_stosm(0x01); 471 /* Loop until driver state indicates finished request */ 472 while (sclp_running_state != sclp_running_state_idle) { 473 /* Check for expired request timer */ 474 if (timer_pending(&sclp_request_timer) && 475 get_clock() > timeout && 476 del_timer(&sclp_request_timer)) 477 sclp_request_timer.function(sclp_request_timer.data); 478 cpu_relax(); 479 } 480 local_irq_disable(); 481 __ctl_load(cr0, 0, 0); 482 if (!irq_context) 483 _local_bh_enable(); 484 local_tick_enable(old_tick); 485 local_irq_restore(flags); 486 } 487 EXPORT_SYMBOL(sclp_sync_wait); 488 489 /* Dispatch changes in send and receive mask to registered listeners. */ 490 static void 491 sclp_dispatch_state_change(void) 492 { 493 struct list_head *l; 494 struct sclp_register *reg; 495 unsigned long flags; 496 sccb_mask_t receive_mask; 497 sccb_mask_t send_mask; 498 499 do { 500 spin_lock_irqsave(&sclp_lock, flags); 501 reg = NULL; 502 list_for_each(l, &sclp_reg_list) { 503 reg = list_entry(l, struct sclp_register, list); 504 receive_mask = reg->send_mask & sclp_receive_mask; 505 send_mask = reg->receive_mask & sclp_send_mask; 506 if (reg->sclp_receive_mask != receive_mask || 507 reg->sclp_send_mask != send_mask) { 508 reg->sclp_receive_mask = receive_mask; 509 reg->sclp_send_mask = send_mask; 510 break; 511 } else 512 reg = NULL; 513 } 514 spin_unlock_irqrestore(&sclp_lock, flags); 515 if (reg && reg->state_change_fn) 516 reg->state_change_fn(reg); 517 } while (reg); 518 } 519 520 struct sclp_statechangebuf { 521 struct evbuf_header header; 522 u8 validity_sclp_active_facility_mask : 1; 523 u8 validity_sclp_receive_mask : 1; 524 u8 validity_sclp_send_mask : 1; 525 u8 validity_read_data_function_mask : 1; 526 u16 _zeros : 12; 527 u16 mask_length; 528 u64 sclp_active_facility_mask; 529 sccb_mask_t sclp_receive_mask; 530 sccb_mask_t sclp_send_mask; 531 u32 read_data_function_mask; 532 } __attribute__((packed)); 533 534 535 /* State change event callback. Inform listeners of changes. */ 536 static void 537 sclp_state_change_cb(struct evbuf_header *evbuf) 538 { 539 unsigned long flags; 540 struct sclp_statechangebuf *scbuf; 541 542 scbuf = (struct sclp_statechangebuf *) evbuf; 543 if (scbuf->mask_length != sizeof(sccb_mask_t)) 544 return; 545 spin_lock_irqsave(&sclp_lock, flags); 546 if (scbuf->validity_sclp_receive_mask) 547 sclp_receive_mask = scbuf->sclp_receive_mask; 548 if (scbuf->validity_sclp_send_mask) 549 sclp_send_mask = scbuf->sclp_send_mask; 550 spin_unlock_irqrestore(&sclp_lock, flags); 551 if (scbuf->validity_sclp_active_facility_mask) 552 sclp_facilities = scbuf->sclp_active_facility_mask; 553 sclp_dispatch_state_change(); 554 } 555 556 static struct sclp_register sclp_state_change_event = { 557 .receive_mask = EVTYP_STATECHANGE_MASK, 558 .receiver_fn = sclp_state_change_cb 559 }; 560 561 /* Calculate receive and send mask of currently registered listeners. 562 * Called while sclp_lock is locked. */ 563 static inline void 564 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 565 { 566 struct list_head *l; 567 struct sclp_register *t; 568 569 *receive_mask = 0; 570 *send_mask = 0; 571 list_for_each(l, &sclp_reg_list) { 572 t = list_entry(l, struct sclp_register, list); 573 *receive_mask |= t->receive_mask; 574 *send_mask |= t->send_mask; 575 } 576 } 577 578 /* Register event listener. Return 0 on success, non-zero otherwise. */ 579 int 580 sclp_register(struct sclp_register *reg) 581 { 582 unsigned long flags; 583 sccb_mask_t receive_mask; 584 sccb_mask_t send_mask; 585 int rc; 586 587 rc = sclp_init(); 588 if (rc) 589 return rc; 590 spin_lock_irqsave(&sclp_lock, flags); 591 /* Check event mask for collisions */ 592 __sclp_get_mask(&receive_mask, &send_mask); 593 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 594 spin_unlock_irqrestore(&sclp_lock, flags); 595 return -EBUSY; 596 } 597 /* Trigger initial state change callback */ 598 reg->sclp_receive_mask = 0; 599 reg->sclp_send_mask = 0; 600 reg->pm_event_posted = 0; 601 list_add(®->list, &sclp_reg_list); 602 spin_unlock_irqrestore(&sclp_lock, flags); 603 rc = sclp_init_mask(1); 604 if (rc) { 605 spin_lock_irqsave(&sclp_lock, flags); 606 list_del(®->list); 607 spin_unlock_irqrestore(&sclp_lock, flags); 608 } 609 return rc; 610 } 611 612 EXPORT_SYMBOL(sclp_register); 613 614 /* Unregister event listener. */ 615 void 616 sclp_unregister(struct sclp_register *reg) 617 { 618 unsigned long flags; 619 620 spin_lock_irqsave(&sclp_lock, flags); 621 list_del(®->list); 622 spin_unlock_irqrestore(&sclp_lock, flags); 623 sclp_init_mask(1); 624 } 625 626 EXPORT_SYMBOL(sclp_unregister); 627 628 /* Remove event buffers which are marked processed. Return the number of 629 * remaining event buffers. */ 630 int 631 sclp_remove_processed(struct sccb_header *sccb) 632 { 633 struct evbuf_header *evbuf; 634 int unprocessed; 635 u16 remaining; 636 637 evbuf = (struct evbuf_header *) (sccb + 1); 638 unprocessed = 0; 639 remaining = sccb->length - sizeof(struct sccb_header); 640 while (remaining > 0) { 641 remaining -= evbuf->length; 642 if (evbuf->flags & 0x80) { 643 sccb->length -= evbuf->length; 644 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 645 remaining); 646 } else { 647 unprocessed++; 648 evbuf = (struct evbuf_header *) 649 ((addr_t) evbuf + evbuf->length); 650 } 651 } 652 return unprocessed; 653 } 654 655 EXPORT_SYMBOL(sclp_remove_processed); 656 657 /* Prepare init mask request. Called while sclp_lock is locked. */ 658 static inline void 659 __sclp_make_init_req(u32 receive_mask, u32 send_mask) 660 { 661 struct init_sccb *sccb; 662 663 sccb = (struct init_sccb *) sclp_init_sccb; 664 clear_page(sccb); 665 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 666 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 667 sclp_init_req.status = SCLP_REQ_FILLED; 668 sclp_init_req.start_count = 0; 669 sclp_init_req.callback = NULL; 670 sclp_init_req.callback_data = NULL; 671 sclp_init_req.sccb = sccb; 672 sccb->header.length = sizeof(struct init_sccb); 673 sccb->mask_length = sizeof(sccb_mask_t); 674 sccb->receive_mask = receive_mask; 675 sccb->send_mask = send_mask; 676 sccb->sclp_receive_mask = 0; 677 sccb->sclp_send_mask = 0; 678 } 679 680 /* Start init mask request. If calculate is non-zero, calculate the mask as 681 * requested by registered listeners. Use zero mask otherwise. Return 0 on 682 * success, non-zero otherwise. */ 683 static int 684 sclp_init_mask(int calculate) 685 { 686 unsigned long flags; 687 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 688 sccb_mask_t receive_mask; 689 sccb_mask_t send_mask; 690 int retry; 691 int rc; 692 unsigned long wait; 693 694 spin_lock_irqsave(&sclp_lock, flags); 695 /* Check if interface is in appropriate state */ 696 if (sclp_mask_state != sclp_mask_state_idle) { 697 spin_unlock_irqrestore(&sclp_lock, flags); 698 return -EBUSY; 699 } 700 if (sclp_activation_state == sclp_activation_state_inactive) { 701 spin_unlock_irqrestore(&sclp_lock, flags); 702 return -EINVAL; 703 } 704 sclp_mask_state = sclp_mask_state_initializing; 705 /* Determine mask */ 706 if (calculate) 707 __sclp_get_mask(&receive_mask, &send_mask); 708 else { 709 receive_mask = 0; 710 send_mask = 0; 711 } 712 rc = -EIO; 713 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 714 /* Prepare request */ 715 __sclp_make_init_req(receive_mask, send_mask); 716 spin_unlock_irqrestore(&sclp_lock, flags); 717 if (sclp_add_request(&sclp_init_req)) { 718 /* Try again later */ 719 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 720 while (time_before(jiffies, wait)) 721 sclp_sync_wait(); 722 spin_lock_irqsave(&sclp_lock, flags); 723 continue; 724 } 725 while (sclp_init_req.status != SCLP_REQ_DONE && 726 sclp_init_req.status != SCLP_REQ_FAILED) 727 sclp_sync_wait(); 728 spin_lock_irqsave(&sclp_lock, flags); 729 if (sclp_init_req.status == SCLP_REQ_DONE && 730 sccb->header.response_code == 0x20) { 731 /* Successful request */ 732 if (calculate) { 733 sclp_receive_mask = sccb->sclp_receive_mask; 734 sclp_send_mask = sccb->sclp_send_mask; 735 } else { 736 sclp_receive_mask = 0; 737 sclp_send_mask = 0; 738 } 739 spin_unlock_irqrestore(&sclp_lock, flags); 740 sclp_dispatch_state_change(); 741 spin_lock_irqsave(&sclp_lock, flags); 742 rc = 0; 743 break; 744 } 745 } 746 sclp_mask_state = sclp_mask_state_idle; 747 spin_unlock_irqrestore(&sclp_lock, flags); 748 return rc; 749 } 750 751 /* Deactivate SCLP interface. On success, new requests will be rejected, 752 * events will no longer be dispatched. Return 0 on success, non-zero 753 * otherwise. */ 754 int 755 sclp_deactivate(void) 756 { 757 unsigned long flags; 758 int rc; 759 760 spin_lock_irqsave(&sclp_lock, flags); 761 /* Deactivate can only be called when active */ 762 if (sclp_activation_state != sclp_activation_state_active) { 763 spin_unlock_irqrestore(&sclp_lock, flags); 764 return -EINVAL; 765 } 766 sclp_activation_state = sclp_activation_state_deactivating; 767 spin_unlock_irqrestore(&sclp_lock, flags); 768 rc = sclp_init_mask(0); 769 spin_lock_irqsave(&sclp_lock, flags); 770 if (rc == 0) 771 sclp_activation_state = sclp_activation_state_inactive; 772 else 773 sclp_activation_state = sclp_activation_state_active; 774 spin_unlock_irqrestore(&sclp_lock, flags); 775 return rc; 776 } 777 778 EXPORT_SYMBOL(sclp_deactivate); 779 780 /* Reactivate SCLP interface after sclp_deactivate. On success, new 781 * requests will be accepted, events will be dispatched again. Return 0 on 782 * success, non-zero otherwise. */ 783 int 784 sclp_reactivate(void) 785 { 786 unsigned long flags; 787 int rc; 788 789 spin_lock_irqsave(&sclp_lock, flags); 790 /* Reactivate can only be called when inactive */ 791 if (sclp_activation_state != sclp_activation_state_inactive) { 792 spin_unlock_irqrestore(&sclp_lock, flags); 793 return -EINVAL; 794 } 795 sclp_activation_state = sclp_activation_state_activating; 796 spin_unlock_irqrestore(&sclp_lock, flags); 797 rc = sclp_init_mask(1); 798 spin_lock_irqsave(&sclp_lock, flags); 799 if (rc == 0) 800 sclp_activation_state = sclp_activation_state_active; 801 else 802 sclp_activation_state = sclp_activation_state_inactive; 803 spin_unlock_irqrestore(&sclp_lock, flags); 804 return rc; 805 } 806 807 EXPORT_SYMBOL(sclp_reactivate); 808 809 /* Handler for external interruption used during initialization. Modify 810 * request state to done. */ 811 static void sclp_check_handler(struct ext_code ext_code, 812 unsigned int param32, unsigned long param64) 813 { 814 u32 finished_sccb; 815 816 kstat_cpu(smp_processor_id()).irqs[EXTINT_SCP]++; 817 finished_sccb = param32 & 0xfffffff8; 818 /* Is this the interrupt we are waiting for? */ 819 if (finished_sccb == 0) 820 return; 821 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) 822 panic("sclp: unsolicited interrupt for buffer at 0x%x\n", 823 finished_sccb); 824 spin_lock(&sclp_lock); 825 if (sclp_running_state == sclp_running_state_running) { 826 sclp_init_req.status = SCLP_REQ_DONE; 827 sclp_running_state = sclp_running_state_idle; 828 } 829 spin_unlock(&sclp_lock); 830 } 831 832 /* Initial init mask request timed out. Modify request state to failed. */ 833 static void 834 sclp_check_timeout(unsigned long data) 835 { 836 unsigned long flags; 837 838 spin_lock_irqsave(&sclp_lock, flags); 839 if (sclp_running_state == sclp_running_state_running) { 840 sclp_init_req.status = SCLP_REQ_FAILED; 841 sclp_running_state = sclp_running_state_idle; 842 } 843 spin_unlock_irqrestore(&sclp_lock, flags); 844 } 845 846 /* Perform a check of the SCLP interface. Return zero if the interface is 847 * available and there are no pending requests from a previous instance. 848 * Return non-zero otherwise. */ 849 static int 850 sclp_check_interface(void) 851 { 852 struct init_sccb *sccb; 853 unsigned long flags; 854 int retry; 855 int rc; 856 857 spin_lock_irqsave(&sclp_lock, flags); 858 /* Prepare init mask command */ 859 rc = register_external_interrupt(0x2401, sclp_check_handler); 860 if (rc) { 861 spin_unlock_irqrestore(&sclp_lock, flags); 862 return rc; 863 } 864 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 865 __sclp_make_init_req(0, 0); 866 sccb = (struct init_sccb *) sclp_init_req.sccb; 867 rc = sclp_service_call(sclp_init_req.command, sccb); 868 if (rc == -EIO) 869 break; 870 sclp_init_req.status = SCLP_REQ_RUNNING; 871 sclp_running_state = sclp_running_state_running; 872 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 873 sclp_check_timeout, 0); 874 spin_unlock_irqrestore(&sclp_lock, flags); 875 /* Enable service-signal interruption - needs to happen 876 * with IRQs enabled. */ 877 service_subclass_irq_register(); 878 /* Wait for signal from interrupt or timeout */ 879 sclp_sync_wait(); 880 /* Disable service-signal interruption - needs to happen 881 * with IRQs enabled. */ 882 service_subclass_irq_unregister(); 883 spin_lock_irqsave(&sclp_lock, flags); 884 del_timer(&sclp_request_timer); 885 if (sclp_init_req.status == SCLP_REQ_DONE && 886 sccb->header.response_code == 0x20) { 887 rc = 0; 888 break; 889 } else 890 rc = -EBUSY; 891 } 892 unregister_external_interrupt(0x2401, sclp_check_handler); 893 spin_unlock_irqrestore(&sclp_lock, flags); 894 return rc; 895 } 896 897 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP 898 * events from interfering with rebooted system. */ 899 static int 900 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 901 { 902 sclp_deactivate(); 903 return NOTIFY_DONE; 904 } 905 906 static struct notifier_block sclp_reboot_notifier = { 907 .notifier_call = sclp_reboot_event 908 }; 909 910 /* 911 * Suspend/resume SCLP notifier implementation 912 */ 913 914 static void sclp_pm_event(enum sclp_pm_event sclp_pm_event, int rollback) 915 { 916 struct sclp_register *reg; 917 unsigned long flags; 918 919 if (!rollback) { 920 spin_lock_irqsave(&sclp_lock, flags); 921 list_for_each_entry(reg, &sclp_reg_list, list) 922 reg->pm_event_posted = 0; 923 spin_unlock_irqrestore(&sclp_lock, flags); 924 } 925 do { 926 spin_lock_irqsave(&sclp_lock, flags); 927 list_for_each_entry(reg, &sclp_reg_list, list) { 928 if (rollback && reg->pm_event_posted) 929 goto found; 930 if (!rollback && !reg->pm_event_posted) 931 goto found; 932 } 933 spin_unlock_irqrestore(&sclp_lock, flags); 934 return; 935 found: 936 spin_unlock_irqrestore(&sclp_lock, flags); 937 if (reg->pm_event_fn) 938 reg->pm_event_fn(reg, sclp_pm_event); 939 reg->pm_event_posted = rollback ? 0 : 1; 940 } while (1); 941 } 942 943 /* 944 * Susend/resume callbacks for platform device 945 */ 946 947 static int sclp_freeze(struct device *dev) 948 { 949 unsigned long flags; 950 int rc; 951 952 sclp_pm_event(SCLP_PM_EVENT_FREEZE, 0); 953 954 spin_lock_irqsave(&sclp_lock, flags); 955 sclp_suspend_state = sclp_suspend_state_suspended; 956 spin_unlock_irqrestore(&sclp_lock, flags); 957 958 /* Init supend data */ 959 memset(&sclp_suspend_req, 0, sizeof(sclp_suspend_req)); 960 sclp_suspend_req.callback = sclp_suspend_req_cb; 961 sclp_suspend_req.status = SCLP_REQ_FILLED; 962 init_completion(&sclp_request_queue_flushed); 963 964 rc = sclp_add_request(&sclp_suspend_req); 965 if (rc == 0) 966 wait_for_completion(&sclp_request_queue_flushed); 967 else if (rc != -ENODATA) 968 goto fail_thaw; 969 970 rc = sclp_deactivate(); 971 if (rc) 972 goto fail_thaw; 973 return 0; 974 975 fail_thaw: 976 spin_lock_irqsave(&sclp_lock, flags); 977 sclp_suspend_state = sclp_suspend_state_running; 978 spin_unlock_irqrestore(&sclp_lock, flags); 979 sclp_pm_event(SCLP_PM_EVENT_THAW, 1); 980 return rc; 981 } 982 983 static int sclp_undo_suspend(enum sclp_pm_event event) 984 { 985 unsigned long flags; 986 int rc; 987 988 rc = sclp_reactivate(); 989 if (rc) 990 return rc; 991 992 spin_lock_irqsave(&sclp_lock, flags); 993 sclp_suspend_state = sclp_suspend_state_running; 994 spin_unlock_irqrestore(&sclp_lock, flags); 995 996 sclp_pm_event(event, 0); 997 return 0; 998 } 999 1000 static int sclp_thaw(struct device *dev) 1001 { 1002 return sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1003 } 1004 1005 static int sclp_restore(struct device *dev) 1006 { 1007 return sclp_undo_suspend(SCLP_PM_EVENT_RESTORE); 1008 } 1009 1010 static const struct dev_pm_ops sclp_pm_ops = { 1011 .freeze = sclp_freeze, 1012 .thaw = sclp_thaw, 1013 .restore = sclp_restore, 1014 }; 1015 1016 static struct platform_driver sclp_pdrv = { 1017 .driver = { 1018 .name = "sclp", 1019 .owner = THIS_MODULE, 1020 .pm = &sclp_pm_ops, 1021 }, 1022 }; 1023 1024 static struct platform_device *sclp_pdev; 1025 1026 /* Initialize SCLP driver. Return zero if driver is operational, non-zero 1027 * otherwise. */ 1028 static int 1029 sclp_init(void) 1030 { 1031 unsigned long flags; 1032 int rc = 0; 1033 1034 spin_lock_irqsave(&sclp_lock, flags); 1035 /* Check for previous or running initialization */ 1036 if (sclp_init_state != sclp_init_state_uninitialized) 1037 goto fail_unlock; 1038 sclp_init_state = sclp_init_state_initializing; 1039 /* Set up variables */ 1040 INIT_LIST_HEAD(&sclp_req_queue); 1041 INIT_LIST_HEAD(&sclp_reg_list); 1042 list_add(&sclp_state_change_event.list, &sclp_reg_list); 1043 init_timer(&sclp_request_timer); 1044 /* Check interface */ 1045 spin_unlock_irqrestore(&sclp_lock, flags); 1046 rc = sclp_check_interface(); 1047 spin_lock_irqsave(&sclp_lock, flags); 1048 if (rc) 1049 goto fail_init_state_uninitialized; 1050 /* Register reboot handler */ 1051 rc = register_reboot_notifier(&sclp_reboot_notifier); 1052 if (rc) 1053 goto fail_init_state_uninitialized; 1054 /* Register interrupt handler */ 1055 rc = register_external_interrupt(0x2401, sclp_interrupt_handler); 1056 if (rc) 1057 goto fail_unregister_reboot_notifier; 1058 sclp_init_state = sclp_init_state_initialized; 1059 spin_unlock_irqrestore(&sclp_lock, flags); 1060 /* Enable service-signal external interruption - needs to happen with 1061 * IRQs enabled. */ 1062 service_subclass_irq_register(); 1063 sclp_init_mask(1); 1064 return 0; 1065 1066 fail_unregister_reboot_notifier: 1067 unregister_reboot_notifier(&sclp_reboot_notifier); 1068 fail_init_state_uninitialized: 1069 sclp_init_state = sclp_init_state_uninitialized; 1070 fail_unlock: 1071 spin_unlock_irqrestore(&sclp_lock, flags); 1072 return rc; 1073 } 1074 1075 /* 1076 * SCLP panic notifier: If we are suspended, we thaw SCLP in order to be able 1077 * to print the panic message. 1078 */ 1079 static int sclp_panic_notify(struct notifier_block *self, 1080 unsigned long event, void *data) 1081 { 1082 if (sclp_suspend_state == sclp_suspend_state_suspended) 1083 sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1084 return NOTIFY_OK; 1085 } 1086 1087 static struct notifier_block sclp_on_panic_nb = { 1088 .notifier_call = sclp_panic_notify, 1089 .priority = SCLP_PANIC_PRIO, 1090 }; 1091 1092 static __init int sclp_initcall(void) 1093 { 1094 int rc; 1095 1096 rc = platform_driver_register(&sclp_pdrv); 1097 if (rc) 1098 return rc; 1099 sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0); 1100 rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0; 1101 if (rc) 1102 goto fail_platform_driver_unregister; 1103 rc = atomic_notifier_chain_register(&panic_notifier_list, 1104 &sclp_on_panic_nb); 1105 if (rc) 1106 goto fail_platform_device_unregister; 1107 1108 return sclp_init(); 1109 1110 fail_platform_device_unregister: 1111 platform_device_unregister(sclp_pdev); 1112 fail_platform_driver_unregister: 1113 platform_driver_unregister(&sclp_pdrv); 1114 return rc; 1115 } 1116 1117 arch_initcall(sclp_initcall); 1118