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/module.h> 11#include <linux/err.h> 12#include <linux/spinlock.h> 13#include <linux/interrupt.h> 14#include <linux/timer.h> 15#include <linux/reboot.h> 16#include <linux/jiffies.h> 17#include <linux/init.h> 18#include <linux/suspend.h> 19#include <linux/completion.h> 20#include <linux/platform_device.h> 21#include <asm/types.h> 22#include <asm/s390_ext.h> 23 24#include "sclp.h" 25 26#define SCLP_HEADER "sclp: " 27 28/* Structure for register_early_external_interrupt. */ 29static ext_int_info_t ext_int_info_hwc; 30 31/* Lock to protect internal data consistency. */ 32static DEFINE_SPINLOCK(sclp_lock); 33 34/* Mask of events that we can send to the sclp interface. */ 35static sccb_mask_t sclp_receive_mask; 36 37/* Mask of events that we can receive from the sclp interface. */ 38static sccb_mask_t sclp_send_mask; 39 40/* List of registered event listeners and senders. */ 41static struct list_head sclp_reg_list; 42 43/* List of queued requests. */ 44static struct list_head sclp_req_queue; 45 46/* Data for read and and init requests. */ 47static struct sclp_req sclp_read_req; 48static struct sclp_req sclp_init_req; 49static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 50static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 51 52/* Suspend request */ 53static DECLARE_COMPLETION(sclp_request_queue_flushed); 54 55static void sclp_suspend_req_cb(struct sclp_req *req, void *data) 56{ 57 complete(&sclp_request_queue_flushed); 58} 59 60static struct sclp_req sclp_suspend_req; 61 62/* Timer for request retries. */ 63static struct timer_list sclp_request_timer; 64 65/* Internal state: is the driver initialized? */ 66static volatile enum sclp_init_state_t { 67 sclp_init_state_uninitialized, 68 sclp_init_state_initializing, 69 sclp_init_state_initialized 70} sclp_init_state = sclp_init_state_uninitialized; 71 72/* Internal state: is a request active at the sclp? */ 73static volatile enum sclp_running_state_t { 74 sclp_running_state_idle, 75 sclp_running_state_running, 76 sclp_running_state_reset_pending 77} sclp_running_state = sclp_running_state_idle; 78 79/* Internal state: is a read request pending? */ 80static volatile enum sclp_reading_state_t { 81 sclp_reading_state_idle, 82 sclp_reading_state_reading 83} sclp_reading_state = sclp_reading_state_idle; 84 85/* Internal state: is the driver currently serving requests? */ 86static volatile enum sclp_activation_state_t { 87 sclp_activation_state_active, 88 sclp_activation_state_deactivating, 89 sclp_activation_state_inactive, 90 sclp_activation_state_activating 91} sclp_activation_state = sclp_activation_state_active; 92 93/* Internal state: is an init mask request pending? */ 94static volatile enum sclp_mask_state_t { 95 sclp_mask_state_idle, 96 sclp_mask_state_initializing 97} sclp_mask_state = sclp_mask_state_idle; 98 99/* Internal state: is the driver suspended? */ 100static enum sclp_suspend_state_t { 101 sclp_suspend_state_running, 102 sclp_suspend_state_suspended, 103} sclp_suspend_state = sclp_suspend_state_running; 104 105/* Maximum retry counts */ 106#define SCLP_INIT_RETRY 3 107#define SCLP_MASK_RETRY 3 108 109/* Timeout intervals in seconds.*/ 110#define SCLP_BUSY_INTERVAL 10 111#define SCLP_RETRY_INTERVAL 30 112 113static void sclp_process_queue(void); 114static void __sclp_make_read_req(void); 115static int sclp_init_mask(int calculate); 116static int sclp_init(void); 117 118/* Perform service call. Return 0 on success, non-zero otherwise. */ 119int 120sclp_service_call(sclp_cmdw_t command, void *sccb) 121{ 122 int cc; 123 124 asm volatile( 125 " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 126 " ipm %0\n" 127 " srl %0,28" 128 : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) 129 : "cc", "memory"); 130 if (cc == 3) 131 return -EIO; 132 if (cc == 2) 133 return -EBUSY; 134 return 0; 135} 136 137 138static void 139__sclp_queue_read_req(void) 140{ 141 if (sclp_reading_state == sclp_reading_state_idle) { 142 sclp_reading_state = sclp_reading_state_reading; 143 __sclp_make_read_req(); 144 /* Add request to head of queue */ 145 list_add(&sclp_read_req.list, &sclp_req_queue); 146 } 147} 148 149/* Set up request retry timer. Called while sclp_lock is locked. */ 150static inline void 151__sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), 152 unsigned long data) 153{ 154 del_timer(&sclp_request_timer); 155 sclp_request_timer.function = function; 156 sclp_request_timer.data = data; 157 sclp_request_timer.expires = jiffies + time; 158 add_timer(&sclp_request_timer); 159} 160 161/* Request timeout handler. Restart the request queue. If DATA is non-zero, 162 * force restart of running request. */ 163static void 164sclp_request_timeout(unsigned long data) 165{ 166 unsigned long flags; 167 168 spin_lock_irqsave(&sclp_lock, flags); 169 if (data) { 170 if (sclp_running_state == sclp_running_state_running) { 171 /* Break running state and queue NOP read event request 172 * to get a defined interface state. */ 173 __sclp_queue_read_req(); 174 sclp_running_state = sclp_running_state_idle; 175 } 176 } else { 177 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 178 sclp_request_timeout, 0); 179 } 180 spin_unlock_irqrestore(&sclp_lock, flags); 181 sclp_process_queue(); 182} 183 184/* Try to start a request. Return zero if the request was successfully 185 * started or if it will be started at a later time. Return non-zero otherwise. 186 * Called while sclp_lock is locked. */ 187static int 188__sclp_start_request(struct sclp_req *req) 189{ 190 int rc; 191 192 if (sclp_running_state != sclp_running_state_idle) 193 return 0; 194 del_timer(&sclp_request_timer); 195 rc = sclp_service_call(req->command, req->sccb); 196 req->start_count++; 197 198 if (rc == 0) { 199 /* Successfully started request */ 200 req->status = SCLP_REQ_RUNNING; 201 sclp_running_state = sclp_running_state_running; 202 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 203 sclp_request_timeout, 1); 204 return 0; 205 } else if (rc == -EBUSY) { 206 /* Try again later */ 207 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 208 sclp_request_timeout, 0); 209 return 0; 210 } 211 /* Request failed */ 212 req->status = SCLP_REQ_FAILED; 213 return rc; 214} 215 216/* Try to start queued requests. */ 217static void 218sclp_process_queue(void) 219{ 220 struct sclp_req *req; 221 int rc; 222 unsigned long flags; 223 224 spin_lock_irqsave(&sclp_lock, flags); 225 if (sclp_running_state != sclp_running_state_idle) { 226 spin_unlock_irqrestore(&sclp_lock, flags); 227 return; 228 } 229 del_timer(&sclp_request_timer); 230 while (!list_empty(&sclp_req_queue)) { 231 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 232 if (!req->sccb) 233 goto do_post; 234 rc = __sclp_start_request(req); 235 if (rc == 0) 236 break; 237 /* Request failed */ 238 if (req->start_count > 1) { 239 /* Cannot abort already submitted request - could still 240 * be active at the SCLP */ 241 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 242 sclp_request_timeout, 0); 243 break; 244 } 245do_post: 246 /* Post-processing for aborted request */ 247 list_del(&req->list); 248 if (req->callback) { 249 spin_unlock_irqrestore(&sclp_lock, flags); 250 req->callback(req, req->callback_data); 251 spin_lock_irqsave(&sclp_lock, flags); 252 } 253 } 254 spin_unlock_irqrestore(&sclp_lock, flags); 255} 256 257static int __sclp_can_add_request(struct sclp_req *req) 258{ 259 if (req == &sclp_suspend_req || req == &sclp_init_req) 260 return 1; 261 if (sclp_suspend_state != sclp_suspend_state_running) 262 return 0; 263 if (sclp_init_state != sclp_init_state_initialized) 264 return 0; 265 if (sclp_activation_state != sclp_activation_state_active) 266 return 0; 267 return 1; 268} 269 270/* Queue a new request. Return zero on success, non-zero otherwise. */ 271int 272sclp_add_request(struct sclp_req *req) 273{ 274 unsigned long flags; 275 int rc; 276 277 spin_lock_irqsave(&sclp_lock, flags); 278 if (!__sclp_can_add_request(req)) { 279 spin_unlock_irqrestore(&sclp_lock, flags); 280 return -EIO; 281 } 282 req->status = SCLP_REQ_QUEUED; 283 req->start_count = 0; 284 list_add_tail(&req->list, &sclp_req_queue); 285 rc = 0; 286 /* Start if request is first in list */ 287 if (sclp_running_state == sclp_running_state_idle && 288 req->list.prev == &sclp_req_queue) { 289 if (!req->sccb) { 290 list_del(&req->list); 291 rc = -ENODATA; 292 goto out; 293 } 294 rc = __sclp_start_request(req); 295 if (rc) 296 list_del(&req->list); 297 } 298out: 299 spin_unlock_irqrestore(&sclp_lock, flags); 300 return rc; 301} 302 303EXPORT_SYMBOL(sclp_add_request); 304 305/* Dispatch events found in request buffer to registered listeners. Return 0 306 * if all events were dispatched, non-zero otherwise. */ 307static int 308sclp_dispatch_evbufs(struct sccb_header *sccb) 309{ 310 unsigned long flags; 311 struct evbuf_header *evbuf; 312 struct list_head *l; 313 struct sclp_register *reg; 314 int offset; 315 int rc; 316 317 spin_lock_irqsave(&sclp_lock, flags); 318 rc = 0; 319 for (offset = sizeof(struct sccb_header); offset < sccb->length; 320 offset += evbuf->length) { 321 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 322 /* Check for malformed hardware response */ 323 if (evbuf->length == 0) 324 break; 325 /* Search for event handler */ 326 reg = NULL; 327 list_for_each(l, &sclp_reg_list) { 328 reg = list_entry(l, struct sclp_register, list); 329 if (reg->receive_mask & (1 << (32 - evbuf->type))) 330 break; 331 else 332 reg = NULL; 333 } 334 if (reg && reg->receiver_fn) { 335 spin_unlock_irqrestore(&sclp_lock, flags); 336 reg->receiver_fn(evbuf); 337 spin_lock_irqsave(&sclp_lock, flags); 338 } else if (reg == NULL) 339 rc = -ENOSYS; 340 } 341 spin_unlock_irqrestore(&sclp_lock, flags); 342 return rc; 343} 344 345/* Read event data request callback. */ 346static void 347sclp_read_cb(struct sclp_req *req, void *data) 348{ 349 unsigned long flags; 350 struct sccb_header *sccb; 351 352 sccb = (struct sccb_header *) req->sccb; 353 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 354 sccb->response_code == 0x220)) 355 sclp_dispatch_evbufs(sccb); 356 spin_lock_irqsave(&sclp_lock, flags); 357 sclp_reading_state = sclp_reading_state_idle; 358 spin_unlock_irqrestore(&sclp_lock, flags); 359} 360 361/* Prepare read event data request. Called while sclp_lock is locked. */ 362static void __sclp_make_read_req(void) 363{ 364 struct sccb_header *sccb; 365 366 sccb = (struct sccb_header *) sclp_read_sccb; 367 clear_page(sccb); 368 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 369 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 370 sclp_read_req.status = SCLP_REQ_QUEUED; 371 sclp_read_req.start_count = 0; 372 sclp_read_req.callback = sclp_read_cb; 373 sclp_read_req.sccb = sccb; 374 sccb->length = PAGE_SIZE; 375 sccb->function_code = 0; 376 sccb->control_mask[2] = 0x80; 377} 378 379/* Search request list for request with matching sccb. Return request if found, 380 * NULL otherwise. Called while sclp_lock is locked. */ 381static inline struct sclp_req * 382__sclp_find_req(u32 sccb) 383{ 384 struct list_head *l; 385 struct sclp_req *req; 386 387 list_for_each(l, &sclp_req_queue) { 388 req = list_entry(l, struct sclp_req, list); 389 if (sccb == (u32) (addr_t) req->sccb) 390 return req; 391 } 392 return NULL; 393} 394 395/* Handler for external interruption. Perform request post-processing. 396 * Prepare read event data request if necessary. Start processing of next 397 * request on queue. */ 398static void 399sclp_interrupt_handler(__u16 code) 400{ 401 struct sclp_req *req; 402 u32 finished_sccb; 403 u32 evbuf_pending; 404 405 spin_lock(&sclp_lock); 406 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 407 evbuf_pending = S390_lowcore.ext_params & 0x3; 408 if (finished_sccb) { 409 del_timer(&sclp_request_timer); 410 sclp_running_state = sclp_running_state_reset_pending; 411 req = __sclp_find_req(finished_sccb); 412 if (req) { 413 /* Request post-processing */ 414 list_del(&req->list); 415 req->status = SCLP_REQ_DONE; 416 if (req->callback) { 417 spin_unlock(&sclp_lock); 418 req->callback(req, req->callback_data); 419 spin_lock(&sclp_lock); 420 } 421 } 422 sclp_running_state = sclp_running_state_idle; 423 } 424 if (evbuf_pending && 425 sclp_activation_state == sclp_activation_state_active) 426 __sclp_queue_read_req(); 427 spin_unlock(&sclp_lock); 428 sclp_process_queue(); 429} 430 431/* Convert interval in jiffies to TOD ticks. */ 432static inline u64 433sclp_tod_from_jiffies(unsigned long jiffies) 434{ 435 return (u64) (jiffies / HZ) << 32; 436} 437 438/* Wait until a currently running request finished. Note: while this function 439 * is running, no timers are served on the calling CPU. */ 440void 441sclp_sync_wait(void) 442{ 443 unsigned long long old_tick; 444 unsigned long flags; 445 unsigned long cr0, cr0_sync; 446 u64 timeout; 447 int irq_context; 448 449 /* We'll be disabling timer interrupts, so we need a custom timeout 450 * mechanism */ 451 timeout = 0; 452 if (timer_pending(&sclp_request_timer)) { 453 /* Get timeout TOD value */ 454 timeout = get_clock() + 455 sclp_tod_from_jiffies(sclp_request_timer.expires - 456 jiffies); 457 } 458 local_irq_save(flags); 459 /* Prevent bottom half from executing once we force interrupts open */ 460 irq_context = in_interrupt(); 461 if (!irq_context) 462 local_bh_disable(); 463 /* Enable service-signal interruption, disable timer interrupts */ 464 old_tick = local_tick_disable(); 465 trace_hardirqs_on(); 466 __ctl_store(cr0, 0, 0); 467 cr0_sync = cr0; 468 cr0_sync &= 0xffff00a0; 469 cr0_sync |= 0x00000200; 470 __ctl_load(cr0_sync, 0, 0); 471 __raw_local_irq_stosm(0x01); 472 /* Loop until driver state indicates finished request */ 473 while (sclp_running_state != sclp_running_state_idle) { 474 /* Check for expired request timer */ 475 if (timer_pending(&sclp_request_timer) && 476 get_clock() > timeout && 477 del_timer(&sclp_request_timer)) 478 sclp_request_timer.function(sclp_request_timer.data); 479 cpu_relax(); 480 } 481 local_irq_disable(); 482 __ctl_load(cr0, 0, 0); 483 if (!irq_context) 484 _local_bh_enable(); 485 local_tick_enable(old_tick); 486 local_irq_restore(flags); 487} 488EXPORT_SYMBOL(sclp_sync_wait); 489 490/* Dispatch changes in send and receive mask to registered listeners. */ 491static void 492sclp_dispatch_state_change(void) 493{ 494 struct list_head *l; 495 struct sclp_register *reg; 496 unsigned long flags; 497 sccb_mask_t receive_mask; 498 sccb_mask_t send_mask; 499 500 do { 501 spin_lock_irqsave(&sclp_lock, flags); 502 reg = NULL; 503 list_for_each(l, &sclp_reg_list) { 504 reg = list_entry(l, struct sclp_register, list); 505 receive_mask = reg->send_mask & sclp_receive_mask; 506 send_mask = reg->receive_mask & sclp_send_mask; 507 if (reg->sclp_receive_mask != receive_mask || 508 reg->sclp_send_mask != send_mask) { 509 reg->sclp_receive_mask = receive_mask; 510 reg->sclp_send_mask = send_mask; 511 break; 512 } else 513 reg = NULL; 514 } 515 spin_unlock_irqrestore(&sclp_lock, flags); 516 if (reg && reg->state_change_fn) 517 reg->state_change_fn(reg); 518 } while (reg); 519} 520 521struct sclp_statechangebuf { 522 struct evbuf_header header; 523 u8 validity_sclp_active_facility_mask : 1; 524 u8 validity_sclp_receive_mask : 1; 525 u8 validity_sclp_send_mask : 1; 526 u8 validity_read_data_function_mask : 1; 527 u16 _zeros : 12; 528 u16 mask_length; 529 u64 sclp_active_facility_mask; 530 sccb_mask_t sclp_receive_mask; 531 sccb_mask_t sclp_send_mask; 532 u32 read_data_function_mask; 533} __attribute__((packed)); 534 535 536/* State change event callback. Inform listeners of changes. */ 537static void 538sclp_state_change_cb(struct evbuf_header *evbuf) 539{ 540 unsigned long flags; 541 struct sclp_statechangebuf *scbuf; 542 543 scbuf = (struct sclp_statechangebuf *) evbuf; 544 if (scbuf->mask_length != sizeof(sccb_mask_t)) 545 return; 546 spin_lock_irqsave(&sclp_lock, flags); 547 if (scbuf->validity_sclp_receive_mask) 548 sclp_receive_mask = scbuf->sclp_receive_mask; 549 if (scbuf->validity_sclp_send_mask) 550 sclp_send_mask = scbuf->sclp_send_mask; 551 spin_unlock_irqrestore(&sclp_lock, flags); 552 if (scbuf->validity_sclp_active_facility_mask) 553 sclp_facilities = scbuf->sclp_active_facility_mask; 554 sclp_dispatch_state_change(); 555} 556 557static struct sclp_register sclp_state_change_event = { 558 .receive_mask = EVTYP_STATECHANGE_MASK, 559 .receiver_fn = sclp_state_change_cb 560}; 561 562/* Calculate receive and send mask of currently registered listeners. 563 * Called while sclp_lock is locked. */ 564static inline void 565__sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 566{ 567 struct list_head *l; 568 struct sclp_register *t; 569 570 *receive_mask = 0; 571 *send_mask = 0; 572 list_for_each(l, &sclp_reg_list) { 573 t = list_entry(l, struct sclp_register, list); 574 *receive_mask |= t->receive_mask; 575 *send_mask |= t->send_mask; 576 } 577} 578 579/* Register event listener. Return 0 on success, non-zero otherwise. */ 580int 581sclp_register(struct sclp_register *reg) 582{ 583 unsigned long flags; 584 sccb_mask_t receive_mask; 585 sccb_mask_t send_mask; 586 int rc; 587 588 rc = sclp_init(); 589 if (rc) 590 return rc; 591 spin_lock_irqsave(&sclp_lock, flags); 592 /* Check event mask for collisions */ 593 __sclp_get_mask(&receive_mask, &send_mask); 594 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 595 spin_unlock_irqrestore(&sclp_lock, flags); 596 return -EBUSY; 597 } 598 /* Trigger initial state change callback */ 599 reg->sclp_receive_mask = 0; 600 reg->sclp_send_mask = 0; 601 reg->pm_event_posted = 0; 602 list_add(®->list, &sclp_reg_list); 603 spin_unlock_irqrestore(&sclp_lock, flags); 604 rc = sclp_init_mask(1); 605 if (rc) { 606 spin_lock_irqsave(&sclp_lock, flags); 607 list_del(®->list); 608 spin_unlock_irqrestore(&sclp_lock, flags); 609 } 610 return rc; 611} 612 613EXPORT_SYMBOL(sclp_register); 614 615/* Unregister event listener. */ 616void 617sclp_unregister(struct sclp_register *reg) 618{ 619 unsigned long flags; 620 621 spin_lock_irqsave(&sclp_lock, flags); 622 list_del(®->list); 623 spin_unlock_irqrestore(&sclp_lock, flags); 624 sclp_init_mask(1); 625} 626 627EXPORT_SYMBOL(sclp_unregister); 628 629/* Remove event buffers which are marked processed. Return the number of 630 * remaining event buffers. */ 631int 632sclp_remove_processed(struct sccb_header *sccb) 633{ 634 struct evbuf_header *evbuf; 635 int unprocessed; 636 u16 remaining; 637 638 evbuf = (struct evbuf_header *) (sccb + 1); 639 unprocessed = 0; 640 remaining = sccb->length - sizeof(struct sccb_header); 641 while (remaining > 0) { 642 remaining -= evbuf->length; 643 if (evbuf->flags & 0x80) { 644 sccb->length -= evbuf->length; 645 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 646 remaining); 647 } else { 648 unprocessed++; 649 evbuf = (struct evbuf_header *) 650 ((addr_t) evbuf + evbuf->length); 651 } 652 } 653 return unprocessed; 654} 655 656EXPORT_SYMBOL(sclp_remove_processed); 657 658struct init_sccb { 659 struct sccb_header header; 660 u16 _reserved; 661 u16 mask_length; 662 sccb_mask_t receive_mask; 663 sccb_mask_t send_mask; 664 sccb_mask_t sclp_receive_mask; 665 sccb_mask_t sclp_send_mask; 666} __attribute__((packed)); 667 668/* Prepare init mask request. Called while sclp_lock is locked. */ 669static inline void 670__sclp_make_init_req(u32 receive_mask, u32 send_mask) 671{ 672 struct init_sccb *sccb; 673 674 sccb = (struct init_sccb *) sclp_init_sccb; 675 clear_page(sccb); 676 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 677 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 678 sclp_init_req.status = SCLP_REQ_FILLED; 679 sclp_init_req.start_count = 0; 680 sclp_init_req.callback = NULL; 681 sclp_init_req.callback_data = NULL; 682 sclp_init_req.sccb = sccb; 683 sccb->header.length = sizeof(struct init_sccb); 684 sccb->mask_length = sizeof(sccb_mask_t); 685 sccb->receive_mask = receive_mask; 686 sccb->send_mask = send_mask; 687 sccb->sclp_receive_mask = 0; 688 sccb->sclp_send_mask = 0; 689} 690 691/* Start init mask request. If calculate is non-zero, calculate the mask as 692 * requested by registered listeners. Use zero mask otherwise. Return 0 on 693 * success, non-zero otherwise. */ 694static int 695sclp_init_mask(int calculate) 696{ 697 unsigned long flags; 698 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 699 sccb_mask_t receive_mask; 700 sccb_mask_t send_mask; 701 int retry; 702 int rc; 703 unsigned long wait; 704 705 spin_lock_irqsave(&sclp_lock, flags); 706 /* Check if interface is in appropriate state */ 707 if (sclp_mask_state != sclp_mask_state_idle) { 708 spin_unlock_irqrestore(&sclp_lock, flags); 709 return -EBUSY; 710 } 711 if (sclp_activation_state == sclp_activation_state_inactive) { 712 spin_unlock_irqrestore(&sclp_lock, flags); 713 return -EINVAL; 714 } 715 sclp_mask_state = sclp_mask_state_initializing; 716 /* Determine mask */ 717 if (calculate) 718 __sclp_get_mask(&receive_mask, &send_mask); 719 else { 720 receive_mask = 0; 721 send_mask = 0; 722 } 723 rc = -EIO; 724 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 725 /* Prepare request */ 726 __sclp_make_init_req(receive_mask, send_mask); 727 spin_unlock_irqrestore(&sclp_lock, flags); 728 if (sclp_add_request(&sclp_init_req)) { 729 /* Try again later */ 730 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 731 while (time_before(jiffies, wait)) 732 sclp_sync_wait(); 733 spin_lock_irqsave(&sclp_lock, flags); 734 continue; 735 } 736 while (sclp_init_req.status != SCLP_REQ_DONE && 737 sclp_init_req.status != SCLP_REQ_FAILED) 738 sclp_sync_wait(); 739 spin_lock_irqsave(&sclp_lock, flags); 740 if (sclp_init_req.status == SCLP_REQ_DONE && 741 sccb->header.response_code == 0x20) { 742 /* Successful request */ 743 if (calculate) { 744 sclp_receive_mask = sccb->sclp_receive_mask; 745 sclp_send_mask = sccb->sclp_send_mask; 746 } else { 747 sclp_receive_mask = 0; 748 sclp_send_mask = 0; 749 } 750 spin_unlock_irqrestore(&sclp_lock, flags); 751 sclp_dispatch_state_change(); 752 spin_lock_irqsave(&sclp_lock, flags); 753 rc = 0; 754 break; 755 } 756 } 757 sclp_mask_state = sclp_mask_state_idle; 758 spin_unlock_irqrestore(&sclp_lock, flags); 759 return rc; 760} 761 762/* Deactivate SCLP interface. On success, new requests will be rejected, 763 * events will no longer be dispatched. Return 0 on success, non-zero 764 * otherwise. */ 765int 766sclp_deactivate(void) 767{ 768 unsigned long flags; 769 int rc; 770 771 spin_lock_irqsave(&sclp_lock, flags); 772 /* Deactivate can only be called when active */ 773 if (sclp_activation_state != sclp_activation_state_active) { 774 spin_unlock_irqrestore(&sclp_lock, flags); 775 return -EINVAL; 776 } 777 sclp_activation_state = sclp_activation_state_deactivating; 778 spin_unlock_irqrestore(&sclp_lock, flags); 779 rc = sclp_init_mask(0); 780 spin_lock_irqsave(&sclp_lock, flags); 781 if (rc == 0) 782 sclp_activation_state = sclp_activation_state_inactive; 783 else 784 sclp_activation_state = sclp_activation_state_active; 785 spin_unlock_irqrestore(&sclp_lock, flags); 786 return rc; 787} 788 789EXPORT_SYMBOL(sclp_deactivate); 790 791/* Reactivate SCLP interface after sclp_deactivate. On success, new 792 * requests will be accepted, events will be dispatched again. Return 0 on 793 * success, non-zero otherwise. */ 794int 795sclp_reactivate(void) 796{ 797 unsigned long flags; 798 int rc; 799 800 spin_lock_irqsave(&sclp_lock, flags); 801 /* Reactivate can only be called when inactive */ 802 if (sclp_activation_state != sclp_activation_state_inactive) { 803 spin_unlock_irqrestore(&sclp_lock, flags); 804 return -EINVAL; 805 } 806 sclp_activation_state = sclp_activation_state_activating; 807 spin_unlock_irqrestore(&sclp_lock, flags); 808 rc = sclp_init_mask(1); 809 spin_lock_irqsave(&sclp_lock, flags); 810 if (rc == 0) 811 sclp_activation_state = sclp_activation_state_active; 812 else 813 sclp_activation_state = sclp_activation_state_inactive; 814 spin_unlock_irqrestore(&sclp_lock, flags); 815 return rc; 816} 817 818EXPORT_SYMBOL(sclp_reactivate); 819 820/* Handler for external interruption used during initialization. Modify 821 * request state to done. */ 822static void 823sclp_check_handler(__u16 code) 824{ 825 u32 finished_sccb; 826 827 finished_sccb = S390_lowcore.ext_params & 0xfffffff8; 828 /* Is this the interrupt we are waiting for? */ 829 if (finished_sccb == 0) 830 return; 831 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) 832 panic("sclp: unsolicited interrupt for buffer at 0x%x\n", 833 finished_sccb); 834 spin_lock(&sclp_lock); 835 if (sclp_running_state == sclp_running_state_running) { 836 sclp_init_req.status = SCLP_REQ_DONE; 837 sclp_running_state = sclp_running_state_idle; 838 } 839 spin_unlock(&sclp_lock); 840} 841 842/* Initial init mask request timed out. Modify request state to failed. */ 843static void 844sclp_check_timeout(unsigned long data) 845{ 846 unsigned long flags; 847 848 spin_lock_irqsave(&sclp_lock, flags); 849 if (sclp_running_state == sclp_running_state_running) { 850 sclp_init_req.status = SCLP_REQ_FAILED; 851 sclp_running_state = sclp_running_state_idle; 852 } 853 spin_unlock_irqrestore(&sclp_lock, flags); 854} 855 856/* Perform a check of the SCLP interface. Return zero if the interface is 857 * available and there are no pending requests from a previous instance. 858 * Return non-zero otherwise. */ 859static int 860sclp_check_interface(void) 861{ 862 struct init_sccb *sccb; 863 unsigned long flags; 864 int retry; 865 int rc; 866 867 spin_lock_irqsave(&sclp_lock, flags); 868 /* Prepare init mask command */ 869 rc = register_early_external_interrupt(0x2401, sclp_check_handler, 870 &ext_int_info_hwc); 871 if (rc) { 872 spin_unlock_irqrestore(&sclp_lock, flags); 873 return rc; 874 } 875 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 876 __sclp_make_init_req(0, 0); 877 sccb = (struct init_sccb *) sclp_init_req.sccb; 878 rc = sclp_service_call(sclp_init_req.command, sccb); 879 if (rc == -EIO) 880 break; 881 sclp_init_req.status = SCLP_REQ_RUNNING; 882 sclp_running_state = sclp_running_state_running; 883 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 884 sclp_check_timeout, 0); 885 spin_unlock_irqrestore(&sclp_lock, flags); 886 /* Enable service-signal interruption - needs to happen 887 * with IRQs enabled. */ 888 ctl_set_bit(0, 9); 889 /* Wait for signal from interrupt or timeout */ 890 sclp_sync_wait(); 891 /* Disable service-signal interruption - needs to happen 892 * with IRQs enabled. */ 893 ctl_clear_bit(0,9); 894 spin_lock_irqsave(&sclp_lock, flags); 895 del_timer(&sclp_request_timer); 896 if (sclp_init_req.status == SCLP_REQ_DONE && 897 sccb->header.response_code == 0x20) { 898 rc = 0; 899 break; 900 } else 901 rc = -EBUSY; 902 } 903 unregister_early_external_interrupt(0x2401, sclp_check_handler, 904 &ext_int_info_hwc); 905 spin_unlock_irqrestore(&sclp_lock, flags); 906 return rc; 907} 908 909/* Reboot event handler. Reset send and receive mask to prevent pending SCLP 910 * events from interfering with rebooted system. */ 911static int 912sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 913{ 914 sclp_deactivate(); 915 return NOTIFY_DONE; 916} 917 918static struct notifier_block sclp_reboot_notifier = { 919 .notifier_call = sclp_reboot_event 920}; 921 922/* 923 * Suspend/resume SCLP notifier implementation 924 */ 925 926static void sclp_pm_event(enum sclp_pm_event sclp_pm_event, int rollback) 927{ 928 struct sclp_register *reg; 929 unsigned long flags; 930 931 if (!rollback) { 932 spin_lock_irqsave(&sclp_lock, flags); 933 list_for_each_entry(reg, &sclp_reg_list, list) 934 reg->pm_event_posted = 0; 935 spin_unlock_irqrestore(&sclp_lock, flags); 936 } 937 do { 938 spin_lock_irqsave(&sclp_lock, flags); 939 list_for_each_entry(reg, &sclp_reg_list, list) { 940 if (rollback && reg->pm_event_posted) 941 goto found; 942 if (!rollback && !reg->pm_event_posted) 943 goto found; 944 } 945 spin_unlock_irqrestore(&sclp_lock, flags); 946 return; 947found: 948 spin_unlock_irqrestore(&sclp_lock, flags); 949 if (reg->pm_event_fn) 950 reg->pm_event_fn(reg, sclp_pm_event); 951 reg->pm_event_posted = rollback ? 0 : 1; 952 } while (1); 953} 954 955/* 956 * Susend/resume callbacks for platform device 957 */ 958 959static int sclp_freeze(struct device *dev) 960{ 961 unsigned long flags; 962 int rc; 963 964 sclp_pm_event(SCLP_PM_EVENT_FREEZE, 0); 965 966 spin_lock_irqsave(&sclp_lock, flags); 967 sclp_suspend_state = sclp_suspend_state_suspended; 968 spin_unlock_irqrestore(&sclp_lock, flags); 969 970 /* Init supend data */ 971 memset(&sclp_suspend_req, 0, sizeof(sclp_suspend_req)); 972 sclp_suspend_req.callback = sclp_suspend_req_cb; 973 sclp_suspend_req.status = SCLP_REQ_FILLED; 974 init_completion(&sclp_request_queue_flushed); 975 976 rc = sclp_add_request(&sclp_suspend_req); 977 if (rc == 0) 978 wait_for_completion(&sclp_request_queue_flushed); 979 else if (rc != -ENODATA) 980 goto fail_thaw; 981 982 rc = sclp_deactivate(); 983 if (rc) 984 goto fail_thaw; 985 return 0; 986 987fail_thaw: 988 spin_lock_irqsave(&sclp_lock, flags); 989 sclp_suspend_state = sclp_suspend_state_running; 990 spin_unlock_irqrestore(&sclp_lock, flags); 991 sclp_pm_event(SCLP_PM_EVENT_THAW, 1); 992 return rc; 993} 994 995static int sclp_undo_suspend(enum sclp_pm_event event) 996{ 997 unsigned long flags; 998 int rc; 999 1000 rc = sclp_reactivate(); 1001 if (rc) 1002 return rc; 1003 1004 spin_lock_irqsave(&sclp_lock, flags); 1005 sclp_suspend_state = sclp_suspend_state_running; 1006 spin_unlock_irqrestore(&sclp_lock, flags); 1007 1008 sclp_pm_event(event, 0); 1009 return 0; 1010} 1011 1012static int sclp_thaw(struct device *dev) 1013{ 1014 return sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1015} 1016 1017static int sclp_restore(struct device *dev) 1018{ 1019 return sclp_undo_suspend(SCLP_PM_EVENT_RESTORE); 1020} 1021 1022static const struct dev_pm_ops sclp_pm_ops = { 1023 .freeze = sclp_freeze, 1024 .thaw = sclp_thaw, 1025 .restore = sclp_restore, 1026}; 1027 1028static struct platform_driver sclp_pdrv = { 1029 .driver = { 1030 .name = "sclp", 1031 .owner = THIS_MODULE, 1032 .pm = &sclp_pm_ops, 1033 }, 1034}; 1035 1036static struct platform_device *sclp_pdev; 1037 1038/* Initialize SCLP driver. Return zero if driver is operational, non-zero 1039 * otherwise. */ 1040static int 1041sclp_init(void) 1042{ 1043 unsigned long flags; 1044 int rc = 0; 1045 1046 spin_lock_irqsave(&sclp_lock, flags); 1047 /* Check for previous or running initialization */ 1048 if (sclp_init_state != sclp_init_state_uninitialized) 1049 goto fail_unlock; 1050 sclp_init_state = sclp_init_state_initializing; 1051 /* Set up variables */ 1052 INIT_LIST_HEAD(&sclp_req_queue); 1053 INIT_LIST_HEAD(&sclp_reg_list); 1054 list_add(&sclp_state_change_event.list, &sclp_reg_list); 1055 init_timer(&sclp_request_timer); 1056 /* Check interface */ 1057 spin_unlock_irqrestore(&sclp_lock, flags); 1058 rc = sclp_check_interface(); 1059 spin_lock_irqsave(&sclp_lock, flags); 1060 if (rc) 1061 goto fail_init_state_uninitialized; 1062 /* Register reboot handler */ 1063 rc = register_reboot_notifier(&sclp_reboot_notifier); 1064 if (rc) 1065 goto fail_init_state_uninitialized; 1066 /* Register interrupt handler */ 1067 rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler, 1068 &ext_int_info_hwc); 1069 if (rc) 1070 goto fail_unregister_reboot_notifier; 1071 sclp_init_state = sclp_init_state_initialized; 1072 spin_unlock_irqrestore(&sclp_lock, flags); 1073 /* Enable service-signal external interruption - needs to happen with 1074 * IRQs enabled. */ 1075 ctl_set_bit(0, 9); 1076 sclp_init_mask(1); 1077 return 0; 1078 1079fail_unregister_reboot_notifier: 1080 unregister_reboot_notifier(&sclp_reboot_notifier); 1081fail_init_state_uninitialized: 1082 sclp_init_state = sclp_init_state_uninitialized; 1083fail_unlock: 1084 spin_unlock_irqrestore(&sclp_lock, flags); 1085 return rc; 1086} 1087 1088/* 1089 * SCLP panic notifier: If we are suspended, we thaw SCLP in order to be able 1090 * to print the panic message. 1091 */ 1092static int sclp_panic_notify(struct notifier_block *self, 1093 unsigned long event, void *data) 1094{ 1095 if (sclp_suspend_state == sclp_suspend_state_suspended) 1096 sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1097 return NOTIFY_OK; 1098} 1099 1100static struct notifier_block sclp_on_panic_nb = { 1101 .notifier_call = sclp_panic_notify, 1102 .priority = SCLP_PANIC_PRIO, 1103}; 1104 1105static __init int sclp_initcall(void) 1106{ 1107 int rc; 1108 1109 rc = platform_driver_register(&sclp_pdrv); 1110 if (rc) 1111 return rc; 1112 sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0); 1113 rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0; 1114 if (rc) 1115 goto fail_platform_driver_unregister; 1116 rc = atomic_notifier_chain_register(&panic_notifier_list, 1117 &sclp_on_panic_nb); 1118 if (rc) 1119 goto fail_platform_device_unregister; 1120 1121 return sclp_init(); 1122 1123fail_platform_device_unregister: 1124 platform_device_unregister(sclp_pdev); 1125fail_platform_driver_unregister: 1126 platform_driver_unregister(&sclp_pdrv); 1127 return rc; 1128} 1129 1130arch_initcall(sclp_initcall); 1131