| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * core function to access sclp interface |
| 4 | * |
| 5 | * Copyright IBM Corp. 1999, 2009 |
| 6 | * |
| 7 | * Author(s): Martin Peschke <mpeschke@de.ibm.com> |
| 8 | * Martin Schwidefsky <schwidefsky@de.ibm.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/kernel_stat.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/err.h> |
| 14 | #include <linux/panic_notifier.h> |
| 15 | #include <linux/spinlock.h> |
| 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/timer.h> |
| 18 | #include <linux/reboot.h> |
| 19 | #include <linux/jiffies.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/platform_device.h> |
| 22 | #include <asm/types.h> |
| 23 | #include <asm/irq.h> |
| 24 | #include <asm/debug.h> |
| 25 | |
| 26 | #include "sclp.h" |
| 27 | |
| 28 | #define SCLP_HEADER "sclp: " |
| 29 | |
| 30 | struct sclp_trace_entry { |
| 31 | char id[4] __nonstring; |
| 32 | u32 a; |
| 33 | u64 b; |
| 34 | }; |
| 35 | |
| 36 | #define SCLP_TRACE_ENTRY_SIZE sizeof(struct sclp_trace_entry) |
| 37 | #define SCLP_TRACE_MAX_SIZE 128 |
| 38 | #define SCLP_TRACE_EVENT_MAX_SIZE 64 |
| 39 | |
| 40 | /* Debug trace area intended for all entries in abbreviated form. */ |
| 41 | DEFINE_STATIC_DEBUG_INFO(sclp_debug, "sclp", 8, 1, SCLP_TRACE_ENTRY_SIZE, |
| 42 | &debug_hex_ascii_view); |
| 43 | |
| 44 | /* Error trace area intended for full entries relating to failed requests. */ |
| 45 | DEFINE_STATIC_DEBUG_INFO(sclp_debug_err, "sclp_err", 4, 1, |
| 46 | SCLP_TRACE_ENTRY_SIZE, &debug_hex_ascii_view); |
| 47 | |
| 48 | /* Lock to protect internal data consistency. */ |
| 49 | static DEFINE_SPINLOCK(sclp_lock); |
| 50 | |
| 51 | /* Mask of events that we can send to the sclp interface. */ |
| 52 | static sccb_mask_t sclp_receive_mask; |
| 53 | |
| 54 | /* Mask of events that we can receive from the sclp interface. */ |
| 55 | static sccb_mask_t sclp_send_mask; |
| 56 | |
| 57 | /* List of registered event listeners and senders. */ |
| 58 | static LIST_HEAD(sclp_reg_list); |
| 59 | |
| 60 | /* List of queued requests. */ |
| 61 | static LIST_HEAD(sclp_req_queue); |
| 62 | |
| 63 | /* Data for read and and init requests. */ |
| 64 | static struct sclp_req sclp_read_req; |
| 65 | static struct sclp_req sclp_init_req; |
| 66 | static void *sclp_read_sccb; |
| 67 | static struct init_sccb *sclp_init_sccb; |
| 68 | |
| 69 | /* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */ |
| 70 | int sclp_console_pages = SCLP_CONSOLE_PAGES; |
| 71 | /* Flag to indicate if buffer pages are dropped on buffer full condition */ |
| 72 | int sclp_console_drop = 1; |
| 73 | /* Number of times the console dropped buffer pages */ |
| 74 | unsigned long sclp_console_full; |
| 75 | |
| 76 | /* The currently active SCLP command word. */ |
| 77 | static sclp_cmdw_t active_cmd; |
| 78 | |
| 79 | static inline void sclp_trace(int prio, char *id, u32 a, u64 b, bool err) |
| 80 | { |
| 81 | struct sclp_trace_entry e; |
| 82 | |
| 83 | memset(&e, 0, sizeof(e)); |
| 84 | strncpy(e.id, id, sizeof(e.id)); |
| 85 | e.a = a; |
| 86 | e.b = b; |
| 87 | debug_event(&sclp_debug, prio, &e, sizeof(e)); |
| 88 | if (err) |
| 89 | debug_event(&sclp_debug_err, 0, &e, sizeof(e)); |
| 90 | } |
| 91 | |
| 92 | static inline int no_zeroes_len(void *data, int len) |
| 93 | { |
| 94 | char *d = data; |
| 95 | |
| 96 | /* Minimize trace area usage by not tracing trailing zeroes. */ |
| 97 | while (len > SCLP_TRACE_ENTRY_SIZE && d[len - 1] == 0) |
| 98 | len--; |
| 99 | |
| 100 | return len; |
| 101 | } |
| 102 | |
| 103 | static inline void sclp_trace_bin(int prio, void *d, int len, int errlen) |
| 104 | { |
| 105 | debug_event(&sclp_debug, prio, d, no_zeroes_len(d, len)); |
| 106 | if (errlen) |
| 107 | debug_event(&sclp_debug_err, 0, d, no_zeroes_len(d, errlen)); |
| 108 | } |
| 109 | |
| 110 | static inline int abbrev_len(sclp_cmdw_t cmd, struct sccb_header *sccb) |
| 111 | { |
| 112 | struct evbuf_header *evbuf = (struct evbuf_header *)(sccb + 1); |
| 113 | int len = sccb->length, limit = SCLP_TRACE_MAX_SIZE; |
| 114 | |
| 115 | /* Full SCCB tracing if debug level is set to max. */ |
| 116 | if (sclp_debug.level == DEBUG_MAX_LEVEL) |
| 117 | return len; |
| 118 | |
| 119 | /* Minimal tracing for console writes. */ |
| 120 | if (cmd == SCLP_CMDW_WRITE_EVENT_DATA && |
| 121 | (evbuf->type == EVTYP_MSG || evbuf->type == EVTYP_VT220MSG)) |
| 122 | limit = SCLP_TRACE_ENTRY_SIZE; |
| 123 | |
| 124 | return min(len, limit); |
| 125 | } |
| 126 | |
| 127 | static inline void sclp_trace_sccb(int prio, char *id, u32 a, u64 b, |
| 128 | sclp_cmdw_t cmd, struct sccb_header *sccb, |
| 129 | bool err) |
| 130 | { |
| 131 | sclp_trace(prio, id, a, b, err); |
| 132 | if (sccb) { |
| 133 | sclp_trace_bin(prio + 1, sccb, abbrev_len(cmd, sccb), |
| 134 | err ? sccb->length : 0); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | static inline void sclp_trace_evbuf(int prio, char *id, u32 a, u64 b, |
| 139 | struct evbuf_header *evbuf, bool err) |
| 140 | { |
| 141 | sclp_trace(prio, id, a, b, err); |
| 142 | sclp_trace_bin(prio + 1, evbuf, |
| 143 | min((int)evbuf->length, (int)SCLP_TRACE_EVENT_MAX_SIZE), |
| 144 | err ? evbuf->length : 0); |
| 145 | } |
| 146 | |
| 147 | static inline void sclp_trace_req(int prio, char *id, struct sclp_req *req, |
| 148 | bool err) |
| 149 | { |
| 150 | struct sccb_header *sccb = req->sccb; |
| 151 | union { |
| 152 | struct { |
| 153 | u16 status; |
| 154 | u16 response; |
| 155 | u16 timeout; |
| 156 | u16 start_count; |
| 157 | }; |
| 158 | u64 b; |
| 159 | } summary; |
| 160 | |
| 161 | summary.status = req->status; |
| 162 | summary.response = sccb ? sccb->response_code : 0; |
| 163 | summary.timeout = (u16)req->queue_timeout; |
| 164 | summary.start_count = (u16)req->start_count; |
| 165 | |
| 166 | sclp_trace(prio, id, __pa(sccb), summary.b, err); |
| 167 | } |
| 168 | |
| 169 | static inline void sclp_trace_register(int prio, char *id, u32 a, u64 b, |
| 170 | struct sclp_register *reg) |
| 171 | { |
| 172 | struct { |
| 173 | u64 receive; |
| 174 | u64 send; |
| 175 | } d; |
| 176 | |
| 177 | d.receive = reg->receive_mask; |
| 178 | d.send = reg->send_mask; |
| 179 | |
| 180 | sclp_trace(prio, id, a, b, false); |
| 181 | sclp_trace_bin(prio, &d, sizeof(d), 0); |
| 182 | } |
| 183 | |
| 184 | static int __init sclp_setup_console_pages(char *str) |
| 185 | { |
| 186 | int pages, rc; |
| 187 | |
| 188 | rc = kstrtoint(str, 0, &pages); |
| 189 | if (!rc && pages >= SCLP_CONSOLE_PAGES) |
| 190 | sclp_console_pages = pages; |
| 191 | return 1; |
| 192 | } |
| 193 | |
| 194 | __setup("sclp_con_pages=", sclp_setup_console_pages); |
| 195 | |
| 196 | static int __init sclp_setup_console_drop(char *str) |
| 197 | { |
| 198 | int drop, rc; |
| 199 | |
| 200 | rc = kstrtoint(str, 0, &drop); |
| 201 | if (!rc) |
| 202 | sclp_console_drop = drop; |
| 203 | return 1; |
| 204 | } |
| 205 | |
| 206 | __setup("sclp_con_drop=", sclp_setup_console_drop); |
| 207 | |
| 208 | /* Timer for request retries. */ |
| 209 | static struct timer_list sclp_request_timer; |
| 210 | |
| 211 | /* Timer for queued requests. */ |
| 212 | static struct timer_list sclp_queue_timer; |
| 213 | |
| 214 | /* Internal state: is a request active at the sclp? */ |
| 215 | static volatile enum sclp_running_state_t { |
| 216 | sclp_running_state_idle, |
| 217 | sclp_running_state_running, |
| 218 | sclp_running_state_reset_pending |
| 219 | } sclp_running_state = sclp_running_state_idle; |
| 220 | |
| 221 | /* Internal state: is a read request pending? */ |
| 222 | static volatile enum sclp_reading_state_t { |
| 223 | sclp_reading_state_idle, |
| 224 | sclp_reading_state_reading |
| 225 | } sclp_reading_state = sclp_reading_state_idle; |
| 226 | |
| 227 | /* Internal state: is the driver currently serving requests? */ |
| 228 | static volatile enum sclp_activation_state_t { |
| 229 | sclp_activation_state_active, |
| 230 | sclp_activation_state_deactivating, |
| 231 | sclp_activation_state_inactive, |
| 232 | sclp_activation_state_activating |
| 233 | } sclp_activation_state = sclp_activation_state_active; |
| 234 | |
| 235 | /* Internal state: is an init mask request pending? */ |
| 236 | static volatile enum sclp_mask_state_t { |
| 237 | sclp_mask_state_idle, |
| 238 | sclp_mask_state_initializing |
| 239 | } sclp_mask_state = sclp_mask_state_idle; |
| 240 | |
| 241 | /* Maximum retry counts */ |
| 242 | #define SCLP_INIT_RETRY 3 |
| 243 | #define SCLP_MASK_RETRY 3 |
| 244 | |
| 245 | /* Timeout intervals in seconds.*/ |
| 246 | #define SCLP_BUSY_INTERVAL 10 |
| 247 | #define SCLP_RETRY_INTERVAL 30 |
| 248 | |
| 249 | static void sclp_request_timeout(bool force_restart); |
| 250 | static void sclp_process_queue(void); |
| 251 | static void __sclp_make_read_req(void); |
| 252 | static int sclp_init_mask(int calculate); |
| 253 | static int sclp_init(void); |
| 254 | |
| 255 | static void |
| 256 | __sclp_queue_read_req(void) |
| 257 | { |
| 258 | if (sclp_reading_state == sclp_reading_state_idle) { |
| 259 | sclp_reading_state = sclp_reading_state_reading; |
| 260 | __sclp_make_read_req(); |
| 261 | /* Add request to head of queue */ |
| 262 | list_add(&sclp_read_req.list, &sclp_req_queue); |
| 263 | } |
| 264 | } |
| 265 | |
| 266 | /* Set up request retry timer. Called while sclp_lock is locked. */ |
| 267 | static inline void |
| 268 | __sclp_set_request_timer(unsigned long time, void (*cb)(struct timer_list *)) |
| 269 | { |
| 270 | del_timer(&sclp_request_timer); |
| 271 | sclp_request_timer.function = cb; |
| 272 | sclp_request_timer.expires = jiffies + time; |
| 273 | add_timer(&sclp_request_timer); |
| 274 | } |
| 275 | |
| 276 | static void sclp_request_timeout_restart(struct timer_list *unused) |
| 277 | { |
| 278 | sclp_request_timeout(true); |
| 279 | } |
| 280 | |
| 281 | static void sclp_request_timeout_normal(struct timer_list *unused) |
| 282 | { |
| 283 | sclp_request_timeout(false); |
| 284 | } |
| 285 | |
| 286 | /* Request timeout handler. Restart the request queue. If force_restart, |
| 287 | * force restart of running request. */ |
| 288 | static void sclp_request_timeout(bool force_restart) |
| 289 | { |
| 290 | unsigned long flags; |
| 291 | |
| 292 | /* TMO: A timeout occurred (a=force_restart) */ |
| 293 | sclp_trace(2, "TMO", force_restart, 0, true); |
| 294 | |
| 295 | spin_lock_irqsave(&sclp_lock, flags); |
| 296 | if (force_restart) { |
| 297 | if (sclp_running_state == sclp_running_state_running) { |
| 298 | /* Break running state and queue NOP read event request |
| 299 | * to get a defined interface state. */ |
| 300 | __sclp_queue_read_req(); |
| 301 | sclp_running_state = sclp_running_state_idle; |
| 302 | } |
| 303 | } else { |
| 304 | __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, |
| 305 | sclp_request_timeout_normal); |
| 306 | } |
| 307 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 308 | sclp_process_queue(); |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * Returns the expire value in jiffies of the next pending request timeout, |
| 313 | * if any. Needs to be called with sclp_lock. |
| 314 | */ |
| 315 | static unsigned long __sclp_req_queue_find_next_timeout(void) |
| 316 | { |
| 317 | unsigned long expires_next = 0; |
| 318 | struct sclp_req *req; |
| 319 | |
| 320 | list_for_each_entry(req, &sclp_req_queue, list) { |
| 321 | if (!req->queue_expires) |
| 322 | continue; |
| 323 | if (!expires_next || |
| 324 | (time_before(req->queue_expires, expires_next))) |
| 325 | expires_next = req->queue_expires; |
| 326 | } |
| 327 | return expires_next; |
| 328 | } |
| 329 | |
| 330 | /* |
| 331 | * Returns expired request, if any, and removes it from the list. |
| 332 | */ |
| 333 | static struct sclp_req *__sclp_req_queue_remove_expired_req(void) |
| 334 | { |
| 335 | unsigned long flags, now; |
| 336 | struct sclp_req *req; |
| 337 | |
| 338 | spin_lock_irqsave(&sclp_lock, flags); |
| 339 | now = jiffies; |
| 340 | /* Don't need list_for_each_safe because we break out after list_del */ |
| 341 | list_for_each_entry(req, &sclp_req_queue, list) { |
| 342 | if (!req->queue_expires) |
| 343 | continue; |
| 344 | if (time_before_eq(req->queue_expires, now)) { |
| 345 | if (req->status == SCLP_REQ_QUEUED) { |
| 346 | req->status = SCLP_REQ_QUEUED_TIMEOUT; |
| 347 | list_del(&req->list); |
| 348 | goto out; |
| 349 | } |
| 350 | } |
| 351 | } |
| 352 | req = NULL; |
| 353 | out: |
| 354 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 355 | return req; |
| 356 | } |
| 357 | |
| 358 | /* |
| 359 | * Timeout handler for queued requests. Removes request from list and |
| 360 | * invokes callback. This timer can be set per request in situations where |
| 361 | * waiting too long would be harmful to the system, e.g. during SE reboot. |
| 362 | */ |
| 363 | static void sclp_req_queue_timeout(struct timer_list *unused) |
| 364 | { |
| 365 | unsigned long flags, expires_next; |
| 366 | struct sclp_req *req; |
| 367 | |
| 368 | do { |
| 369 | req = __sclp_req_queue_remove_expired_req(); |
| 370 | |
| 371 | if (req) { |
| 372 | /* RQTM: Request timed out (a=sccb, b=summary) */ |
| 373 | sclp_trace_req(2, "RQTM", req, true); |
| 374 | } |
| 375 | |
| 376 | if (req && req->callback) |
| 377 | req->callback(req, req->callback_data); |
| 378 | } while (req); |
| 379 | |
| 380 | spin_lock_irqsave(&sclp_lock, flags); |
| 381 | expires_next = __sclp_req_queue_find_next_timeout(); |
| 382 | if (expires_next) |
| 383 | mod_timer(&sclp_queue_timer, expires_next); |
| 384 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 385 | } |
| 386 | |
| 387 | static int sclp_service_call_trace(sclp_cmdw_t command, void *sccb) |
| 388 | { |
| 389 | static u64 srvc_count; |
| 390 | int rc; |
| 391 | |
| 392 | /* SRV1: Service call about to be issued (a=command, b=sccb address) */ |
| 393 | sclp_trace_sccb(0, "SRV1", command, (u64)sccb, command, sccb, false); |
| 394 | |
| 395 | rc = sclp_service_call(command, sccb); |
| 396 | |
| 397 | /* SRV2: Service call was issued (a=rc, b=SRVC sequence number) */ |
| 398 | sclp_trace(0, "SRV2", -rc, ++srvc_count, rc != 0); |
| 399 | |
| 400 | if (rc == 0) |
| 401 | active_cmd = command; |
| 402 | |
| 403 | return rc; |
| 404 | } |
| 405 | |
| 406 | /* Try to start a request. Return zero if the request was successfully |
| 407 | * started or if it will be started at a later time. Return non-zero otherwise. |
| 408 | * Called while sclp_lock is locked. */ |
| 409 | static int |
| 410 | __sclp_start_request(struct sclp_req *req) |
| 411 | { |
| 412 | int rc; |
| 413 | |
| 414 | if (sclp_running_state != sclp_running_state_idle) |
| 415 | return 0; |
| 416 | del_timer(&sclp_request_timer); |
| 417 | rc = sclp_service_call_trace(req->command, req->sccb); |
| 418 | req->start_count++; |
| 419 | |
| 420 | if (rc == 0) { |
| 421 | /* Successfully started request */ |
| 422 | req->status = SCLP_REQ_RUNNING; |
| 423 | sclp_running_state = sclp_running_state_running; |
| 424 | __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, |
| 425 | sclp_request_timeout_restart); |
| 426 | return 0; |
| 427 | } else if (rc == -EBUSY) { |
| 428 | /* Try again later */ |
| 429 | __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, |
| 430 | sclp_request_timeout_normal); |
| 431 | return 0; |
| 432 | } |
| 433 | /* Request failed */ |
| 434 | req->status = SCLP_REQ_FAILED; |
| 435 | return rc; |
| 436 | } |
| 437 | |
| 438 | /* Try to start queued requests. */ |
| 439 | static void |
| 440 | sclp_process_queue(void) |
| 441 | { |
| 442 | struct sclp_req *req; |
| 443 | int rc; |
| 444 | unsigned long flags; |
| 445 | |
| 446 | spin_lock_irqsave(&sclp_lock, flags); |
| 447 | if (sclp_running_state != sclp_running_state_idle) { |
| 448 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 449 | return; |
| 450 | } |
| 451 | del_timer(&sclp_request_timer); |
| 452 | while (!list_empty(&sclp_req_queue)) { |
| 453 | req = list_entry(sclp_req_queue.next, struct sclp_req, list); |
| 454 | rc = __sclp_start_request(req); |
| 455 | if (rc == 0) |
| 456 | break; |
| 457 | /* Request failed */ |
| 458 | if (req->start_count > 1) { |
| 459 | /* Cannot abort already submitted request - could still |
| 460 | * be active at the SCLP */ |
| 461 | __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, |
| 462 | sclp_request_timeout_normal); |
| 463 | break; |
| 464 | } |
| 465 | /* Post-processing for aborted request */ |
| 466 | list_del(&req->list); |
| 467 | |
| 468 | /* RQAB: Request aborted (a=sccb, b=summary) */ |
| 469 | sclp_trace_req(2, "RQAB", req, true); |
| 470 | |
| 471 | if (req->callback) { |
| 472 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 473 | req->callback(req, req->callback_data); |
| 474 | spin_lock_irqsave(&sclp_lock, flags); |
| 475 | } |
| 476 | } |
| 477 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 478 | } |
| 479 | |
| 480 | static int __sclp_can_add_request(struct sclp_req *req) |
| 481 | { |
| 482 | if (req == &sclp_init_req) |
| 483 | return 1; |
| 484 | if (sclp_init_state != sclp_init_state_initialized) |
| 485 | return 0; |
| 486 | if (sclp_activation_state != sclp_activation_state_active) |
| 487 | return 0; |
| 488 | return 1; |
| 489 | } |
| 490 | |
| 491 | /* Queue a new request. Return zero on success, non-zero otherwise. */ |
| 492 | int |
| 493 | sclp_add_request(struct sclp_req *req) |
| 494 | { |
| 495 | unsigned long flags; |
| 496 | int rc; |
| 497 | |
| 498 | spin_lock_irqsave(&sclp_lock, flags); |
| 499 | if (!__sclp_can_add_request(req)) { |
| 500 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 501 | return -EIO; |
| 502 | } |
| 503 | |
| 504 | /* RQAD: Request was added (a=sccb, b=caller) */ |
| 505 | sclp_trace(2, "RQAD", __pa(req->sccb), _RET_IP_, false); |
| 506 | |
| 507 | req->status = SCLP_REQ_QUEUED; |
| 508 | req->start_count = 0; |
| 509 | list_add_tail(&req->list, &sclp_req_queue); |
| 510 | rc = 0; |
| 511 | if (req->queue_timeout) { |
| 512 | req->queue_expires = jiffies + req->queue_timeout * HZ; |
| 513 | if (!timer_pending(&sclp_queue_timer) || |
| 514 | time_after(sclp_queue_timer.expires, req->queue_expires)) |
| 515 | mod_timer(&sclp_queue_timer, req->queue_expires); |
| 516 | } else |
| 517 | req->queue_expires = 0; |
| 518 | /* Start if request is first in list */ |
| 519 | if (sclp_running_state == sclp_running_state_idle && |
| 520 | req->list.prev == &sclp_req_queue) { |
| 521 | rc = __sclp_start_request(req); |
| 522 | if (rc) |
| 523 | list_del(&req->list); |
| 524 | } |
| 525 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 526 | return rc; |
| 527 | } |
| 528 | |
| 529 | EXPORT_SYMBOL(sclp_add_request); |
| 530 | |
| 531 | /* Dispatch events found in request buffer to registered listeners. Return 0 |
| 532 | * if all events were dispatched, non-zero otherwise. */ |
| 533 | static int |
| 534 | sclp_dispatch_evbufs(struct sccb_header *sccb) |
| 535 | { |
| 536 | unsigned long flags; |
| 537 | struct evbuf_header *evbuf; |
| 538 | struct list_head *l; |
| 539 | struct sclp_register *reg; |
| 540 | int offset; |
| 541 | int rc; |
| 542 | |
| 543 | spin_lock_irqsave(&sclp_lock, flags); |
| 544 | rc = 0; |
| 545 | for (offset = sizeof(struct sccb_header); offset < sccb->length; |
| 546 | offset += evbuf->length) { |
| 547 | evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); |
| 548 | /* Check for malformed hardware response */ |
| 549 | if (evbuf->length == 0) |
| 550 | break; |
| 551 | /* Search for event handler */ |
| 552 | reg = NULL; |
| 553 | list_for_each(l, &sclp_reg_list) { |
| 554 | reg = list_entry(l, struct sclp_register, list); |
| 555 | if (reg->receive_mask & SCLP_EVTYP_MASK(evbuf->type)) |
| 556 | break; |
| 557 | else |
| 558 | reg = NULL; |
| 559 | } |
| 560 | |
| 561 | /* EVNT: Event callback (b=receiver) */ |
| 562 | sclp_trace_evbuf(2, "EVNT", 0, reg ? (u64)reg->receiver_fn : 0, |
| 563 | evbuf, !reg); |
| 564 | |
| 565 | if (reg && reg->receiver_fn) { |
| 566 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 567 | reg->receiver_fn(evbuf); |
| 568 | spin_lock_irqsave(&sclp_lock, flags); |
| 569 | } else if (reg == NULL) |
| 570 | rc = -EOPNOTSUPP; |
| 571 | } |
| 572 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 573 | return rc; |
| 574 | } |
| 575 | |
| 576 | /* Read event data request callback. */ |
| 577 | static void |
| 578 | sclp_read_cb(struct sclp_req *req, void *data) |
| 579 | { |
| 580 | unsigned long flags; |
| 581 | struct sccb_header *sccb; |
| 582 | |
| 583 | sccb = (struct sccb_header *) req->sccb; |
| 584 | if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || |
| 585 | sccb->response_code == 0x220)) |
| 586 | sclp_dispatch_evbufs(sccb); |
| 587 | spin_lock_irqsave(&sclp_lock, flags); |
| 588 | sclp_reading_state = sclp_reading_state_idle; |
| 589 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 590 | } |
| 591 | |
| 592 | /* Prepare read event data request. Called while sclp_lock is locked. */ |
| 593 | static void __sclp_make_read_req(void) |
| 594 | { |
| 595 | struct sccb_header *sccb; |
| 596 | |
| 597 | sccb = (struct sccb_header *) sclp_read_sccb; |
| 598 | clear_page(sccb); |
| 599 | memset(&sclp_read_req, 0, sizeof(struct sclp_req)); |
| 600 | sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; |
| 601 | sclp_read_req.status = SCLP_REQ_QUEUED; |
| 602 | sclp_read_req.start_count = 0; |
| 603 | sclp_read_req.callback = sclp_read_cb; |
| 604 | sclp_read_req.sccb = sccb; |
| 605 | sccb->length = PAGE_SIZE; |
| 606 | sccb->function_code = 0; |
| 607 | sccb->control_mask[2] = 0x80; |
| 608 | } |
| 609 | |
| 610 | /* Search request list for request with matching sccb. Return request if found, |
| 611 | * NULL otherwise. Called while sclp_lock is locked. */ |
| 612 | static inline struct sclp_req * |
| 613 | __sclp_find_req(u32 sccb) |
| 614 | { |
| 615 | struct list_head *l; |
| 616 | struct sclp_req *req; |
| 617 | |
| 618 | list_for_each(l, &sclp_req_queue) { |
| 619 | req = list_entry(l, struct sclp_req, list); |
| 620 | if (sccb == __pa(req->sccb)) |
| 621 | return req; |
| 622 | } |
| 623 | return NULL; |
| 624 | } |
| 625 | |
| 626 | static bool ok_response(u32 sccb_int, sclp_cmdw_t cmd) |
| 627 | { |
| 628 | struct sccb_header *sccb = (struct sccb_header *)__va(sccb_int); |
| 629 | struct evbuf_header *evbuf; |
| 630 | u16 response; |
| 631 | |
| 632 | if (!sccb) |
| 633 | return true; |
| 634 | |
| 635 | /* Check SCCB response. */ |
| 636 | response = sccb->response_code & 0xff; |
| 637 | if (response != 0x10 && response != 0x20) |
| 638 | return false; |
| 639 | |
| 640 | /* Check event-processed flag on outgoing events. */ |
| 641 | if (cmd == SCLP_CMDW_WRITE_EVENT_DATA) { |
| 642 | evbuf = (struct evbuf_header *)(sccb + 1); |
| 643 | if (!(evbuf->flags & 0x80)) |
| 644 | return false; |
| 645 | } |
| 646 | |
| 647 | return true; |
| 648 | } |
| 649 | |
| 650 | /* Handler for external interruption. Perform request post-processing. |
| 651 | * Prepare read event data request if necessary. Start processing of next |
| 652 | * request on queue. */ |
| 653 | static void sclp_interrupt_handler(struct ext_code ext_code, |
| 654 | unsigned int param32, unsigned long param64) |
| 655 | { |
| 656 | struct sclp_req *req; |
| 657 | u32 finished_sccb; |
| 658 | u32 evbuf_pending; |
| 659 | |
| 660 | inc_irq_stat(IRQEXT_SCP); |
| 661 | spin_lock(&sclp_lock); |
| 662 | finished_sccb = param32 & 0xfffffff8; |
| 663 | evbuf_pending = param32 & 0x3; |
| 664 | |
| 665 | /* INT: Interrupt received (a=intparm, b=cmd) */ |
| 666 | sclp_trace_sccb(0, "INT", param32, active_cmd, active_cmd, |
| 667 | (struct sccb_header *)__va(finished_sccb), |
| 668 | !ok_response(finished_sccb, active_cmd)); |
| 669 | |
| 670 | if (finished_sccb) { |
| 671 | del_timer(&sclp_request_timer); |
| 672 | sclp_running_state = sclp_running_state_reset_pending; |
| 673 | req = __sclp_find_req(finished_sccb); |
| 674 | if (req) { |
| 675 | /* Request post-processing */ |
| 676 | list_del(&req->list); |
| 677 | req->status = SCLP_REQ_DONE; |
| 678 | |
| 679 | /* RQOK: Request success (a=sccb, b=summary) */ |
| 680 | sclp_trace_req(2, "RQOK", req, false); |
| 681 | |
| 682 | if (req->callback) { |
| 683 | spin_unlock(&sclp_lock); |
| 684 | req->callback(req, req->callback_data); |
| 685 | spin_lock(&sclp_lock); |
| 686 | } |
| 687 | } else { |
| 688 | /* UNEX: Unexpected SCCB completion (a=sccb address) */ |
| 689 | sclp_trace(0, "UNEX", finished_sccb, 0, true); |
| 690 | } |
| 691 | sclp_running_state = sclp_running_state_idle; |
| 692 | active_cmd = 0; |
| 693 | } |
| 694 | if (evbuf_pending && |
| 695 | sclp_activation_state == sclp_activation_state_active) |
| 696 | __sclp_queue_read_req(); |
| 697 | spin_unlock(&sclp_lock); |
| 698 | sclp_process_queue(); |
| 699 | } |
| 700 | |
| 701 | /* Convert interval in jiffies to TOD ticks. */ |
| 702 | static inline u64 |
| 703 | sclp_tod_from_jiffies(unsigned long jiffies) |
| 704 | { |
| 705 | return (u64) (jiffies / HZ) << 32; |
| 706 | } |
| 707 | |
| 708 | /* Wait until a currently running request finished. Note: while this function |
| 709 | * is running, no timers are served on the calling CPU. */ |
| 710 | void |
| 711 | sclp_sync_wait(void) |
| 712 | { |
| 713 | unsigned long long old_tick; |
| 714 | unsigned long flags; |
| 715 | unsigned long cr0, cr0_sync; |
| 716 | static u64 sync_count; |
| 717 | u64 timeout; |
| 718 | int irq_context; |
| 719 | |
| 720 | /* SYN1: Synchronous wait start (a=runstate, b=sync count) */ |
| 721 | sclp_trace(4, "SYN1", sclp_running_state, ++sync_count, false); |
| 722 | |
| 723 | /* We'll be disabling timer interrupts, so we need a custom timeout |
| 724 | * mechanism */ |
| 725 | timeout = 0; |
| 726 | if (timer_pending(&sclp_request_timer)) { |
| 727 | /* Get timeout TOD value */ |
| 728 | timeout = get_tod_clock_fast() + |
| 729 | sclp_tod_from_jiffies(sclp_request_timer.expires - |
| 730 | jiffies); |
| 731 | } |
| 732 | local_irq_save(flags); |
| 733 | /* Prevent bottom half from executing once we force interrupts open */ |
| 734 | irq_context = in_interrupt(); |
| 735 | if (!irq_context) |
| 736 | local_bh_disable(); |
| 737 | /* Enable service-signal interruption, disable timer interrupts */ |
| 738 | old_tick = local_tick_disable(); |
| 739 | trace_hardirqs_on(); |
| 740 | __ctl_store(cr0, 0, 0); |
| 741 | cr0_sync = cr0 & ~CR0_IRQ_SUBCLASS_MASK; |
| 742 | cr0_sync |= 1UL << (63 - 54); |
| 743 | __ctl_load(cr0_sync, 0, 0); |
| 744 | __arch_local_irq_stosm(0x01); |
| 745 | /* Loop until driver state indicates finished request */ |
| 746 | while (sclp_running_state != sclp_running_state_idle) { |
| 747 | /* Check for expired request timer */ |
| 748 | if (get_tod_clock_fast() > timeout && del_timer(&sclp_request_timer)) |
| 749 | sclp_request_timer.function(&sclp_request_timer); |
| 750 | cpu_relax(); |
| 751 | } |
| 752 | local_irq_disable(); |
| 753 | __ctl_load(cr0, 0, 0); |
| 754 | if (!irq_context) |
| 755 | _local_bh_enable(); |
| 756 | local_tick_enable(old_tick); |
| 757 | local_irq_restore(flags); |
| 758 | |
| 759 | /* SYN2: Synchronous wait end (a=runstate, b=sync_count) */ |
| 760 | sclp_trace(4, "SYN2", sclp_running_state, sync_count, false); |
| 761 | } |
| 762 | EXPORT_SYMBOL(sclp_sync_wait); |
| 763 | |
| 764 | /* Dispatch changes in send and receive mask to registered listeners. */ |
| 765 | static void |
| 766 | sclp_dispatch_state_change(void) |
| 767 | { |
| 768 | struct list_head *l; |
| 769 | struct sclp_register *reg; |
| 770 | unsigned long flags; |
| 771 | sccb_mask_t receive_mask; |
| 772 | sccb_mask_t send_mask; |
| 773 | |
| 774 | do { |
| 775 | spin_lock_irqsave(&sclp_lock, flags); |
| 776 | reg = NULL; |
| 777 | list_for_each(l, &sclp_reg_list) { |
| 778 | reg = list_entry(l, struct sclp_register, list); |
| 779 | receive_mask = reg->send_mask & sclp_receive_mask; |
| 780 | send_mask = reg->receive_mask & sclp_send_mask; |
| 781 | if (reg->sclp_receive_mask != receive_mask || |
| 782 | reg->sclp_send_mask != send_mask) { |
| 783 | reg->sclp_receive_mask = receive_mask; |
| 784 | reg->sclp_send_mask = send_mask; |
| 785 | break; |
| 786 | } else |
| 787 | reg = NULL; |
| 788 | } |
| 789 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 790 | if (reg && reg->state_change_fn) { |
| 791 | /* STCG: State-change callback (b=callback) */ |
| 792 | sclp_trace(2, "STCG", 0, (u64)reg->state_change_fn, |
| 793 | false); |
| 794 | |
| 795 | reg->state_change_fn(reg); |
| 796 | } |
| 797 | } while (reg); |
| 798 | } |
| 799 | |
| 800 | struct sclp_statechangebuf { |
| 801 | struct evbuf_header header; |
| 802 | u8 validity_sclp_active_facility_mask : 1; |
| 803 | u8 validity_sclp_receive_mask : 1; |
| 804 | u8 validity_sclp_send_mask : 1; |
| 805 | u8 validity_read_data_function_mask : 1; |
| 806 | u16 _zeros : 12; |
| 807 | u16 mask_length; |
| 808 | u64 sclp_active_facility_mask; |
| 809 | u8 masks[2 * 1021 + 4]; /* variable length */ |
| 810 | /* |
| 811 | * u8 sclp_receive_mask[mask_length]; |
| 812 | * u8 sclp_send_mask[mask_length]; |
| 813 | * u32 read_data_function_mask; |
| 814 | */ |
| 815 | } __attribute__((packed)); |
| 816 | |
| 817 | |
| 818 | /* State change event callback. Inform listeners of changes. */ |
| 819 | static void |
| 820 | sclp_state_change_cb(struct evbuf_header *evbuf) |
| 821 | { |
| 822 | unsigned long flags; |
| 823 | struct sclp_statechangebuf *scbuf; |
| 824 | |
| 825 | BUILD_BUG_ON(sizeof(struct sclp_statechangebuf) > PAGE_SIZE); |
| 826 | |
| 827 | scbuf = (struct sclp_statechangebuf *) evbuf; |
| 828 | spin_lock_irqsave(&sclp_lock, flags); |
| 829 | if (scbuf->validity_sclp_receive_mask) |
| 830 | sclp_receive_mask = sccb_get_recv_mask(scbuf); |
| 831 | if (scbuf->validity_sclp_send_mask) |
| 832 | sclp_send_mask = sccb_get_send_mask(scbuf); |
| 833 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 834 | if (scbuf->validity_sclp_active_facility_mask) |
| 835 | sclp.facilities = scbuf->sclp_active_facility_mask; |
| 836 | sclp_dispatch_state_change(); |
| 837 | } |
| 838 | |
| 839 | static struct sclp_register sclp_state_change_event = { |
| 840 | .receive_mask = EVTYP_STATECHANGE_MASK, |
| 841 | .receiver_fn = sclp_state_change_cb |
| 842 | }; |
| 843 | |
| 844 | /* Calculate receive and send mask of currently registered listeners. |
| 845 | * Called while sclp_lock is locked. */ |
| 846 | static inline void |
| 847 | __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) |
| 848 | { |
| 849 | struct list_head *l; |
| 850 | struct sclp_register *t; |
| 851 | |
| 852 | *receive_mask = 0; |
| 853 | *send_mask = 0; |
| 854 | list_for_each(l, &sclp_reg_list) { |
| 855 | t = list_entry(l, struct sclp_register, list); |
| 856 | *receive_mask |= t->receive_mask; |
| 857 | *send_mask |= t->send_mask; |
| 858 | } |
| 859 | } |
| 860 | |
| 861 | /* Register event listener. Return 0 on success, non-zero otherwise. */ |
| 862 | int |
| 863 | sclp_register(struct sclp_register *reg) |
| 864 | { |
| 865 | unsigned long flags; |
| 866 | sccb_mask_t receive_mask; |
| 867 | sccb_mask_t send_mask; |
| 868 | int rc; |
| 869 | |
| 870 | /* REG: Event listener registered (b=caller) */ |
| 871 | sclp_trace_register(2, "REG", 0, _RET_IP_, reg); |
| 872 | |
| 873 | rc = sclp_init(); |
| 874 | if (rc) |
| 875 | return rc; |
| 876 | spin_lock_irqsave(&sclp_lock, flags); |
| 877 | /* Check event mask for collisions */ |
| 878 | __sclp_get_mask(&receive_mask, &send_mask); |
| 879 | if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { |
| 880 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 881 | return -EBUSY; |
| 882 | } |
| 883 | /* Trigger initial state change callback */ |
| 884 | reg->sclp_receive_mask = 0; |
| 885 | reg->sclp_send_mask = 0; |
| 886 | list_add(®->list, &sclp_reg_list); |
| 887 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 888 | rc = sclp_init_mask(1); |
| 889 | if (rc) { |
| 890 | spin_lock_irqsave(&sclp_lock, flags); |
| 891 | list_del(®->list); |
| 892 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 893 | } |
| 894 | return rc; |
| 895 | } |
| 896 | |
| 897 | EXPORT_SYMBOL(sclp_register); |
| 898 | |
| 899 | /* Unregister event listener. */ |
| 900 | void |
| 901 | sclp_unregister(struct sclp_register *reg) |
| 902 | { |
| 903 | unsigned long flags; |
| 904 | |
| 905 | /* UREG: Event listener unregistered (b=caller) */ |
| 906 | sclp_trace_register(2, "UREG", 0, _RET_IP_, reg); |
| 907 | |
| 908 | spin_lock_irqsave(&sclp_lock, flags); |
| 909 | list_del(®->list); |
| 910 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 911 | sclp_init_mask(1); |
| 912 | } |
| 913 | |
| 914 | EXPORT_SYMBOL(sclp_unregister); |
| 915 | |
| 916 | /* Remove event buffers which are marked processed. Return the number of |
| 917 | * remaining event buffers. */ |
| 918 | int |
| 919 | sclp_remove_processed(struct sccb_header *sccb) |
| 920 | { |
| 921 | struct evbuf_header *evbuf; |
| 922 | int unprocessed; |
| 923 | u16 remaining; |
| 924 | |
| 925 | evbuf = (struct evbuf_header *) (sccb + 1); |
| 926 | unprocessed = 0; |
| 927 | remaining = sccb->length - sizeof(struct sccb_header); |
| 928 | while (remaining > 0) { |
| 929 | remaining -= evbuf->length; |
| 930 | if (evbuf->flags & 0x80) { |
| 931 | sccb->length -= evbuf->length; |
| 932 | memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), |
| 933 | remaining); |
| 934 | } else { |
| 935 | unprocessed++; |
| 936 | evbuf = (struct evbuf_header *) |
| 937 | ((addr_t) evbuf + evbuf->length); |
| 938 | } |
| 939 | } |
| 940 | return unprocessed; |
| 941 | } |
| 942 | |
| 943 | EXPORT_SYMBOL(sclp_remove_processed); |
| 944 | |
| 945 | /* Prepare init mask request. Called while sclp_lock is locked. */ |
| 946 | static inline void |
| 947 | __sclp_make_init_req(sccb_mask_t receive_mask, sccb_mask_t send_mask) |
| 948 | { |
| 949 | struct init_sccb *sccb = sclp_init_sccb; |
| 950 | |
| 951 | clear_page(sccb); |
| 952 | memset(&sclp_init_req, 0, sizeof(struct sclp_req)); |
| 953 | sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; |
| 954 | sclp_init_req.status = SCLP_REQ_FILLED; |
| 955 | sclp_init_req.start_count = 0; |
| 956 | sclp_init_req.callback = NULL; |
| 957 | sclp_init_req.callback_data = NULL; |
| 958 | sclp_init_req.sccb = sccb; |
| 959 | sccb->header.length = sizeof(*sccb); |
| 960 | if (sclp_mask_compat_mode) |
| 961 | sccb->mask_length = SCLP_MASK_SIZE_COMPAT; |
| 962 | else |
| 963 | sccb->mask_length = sizeof(sccb_mask_t); |
| 964 | sccb_set_recv_mask(sccb, receive_mask); |
| 965 | sccb_set_send_mask(sccb, send_mask); |
| 966 | sccb_set_sclp_recv_mask(sccb, 0); |
| 967 | sccb_set_sclp_send_mask(sccb, 0); |
| 968 | } |
| 969 | |
| 970 | /* Start init mask request. If calculate is non-zero, calculate the mask as |
| 971 | * requested by registered listeners. Use zero mask otherwise. Return 0 on |
| 972 | * success, non-zero otherwise. */ |
| 973 | static int |
| 974 | sclp_init_mask(int calculate) |
| 975 | { |
| 976 | unsigned long flags; |
| 977 | struct init_sccb *sccb = sclp_init_sccb; |
| 978 | sccb_mask_t receive_mask; |
| 979 | sccb_mask_t send_mask; |
| 980 | int retry; |
| 981 | int rc; |
| 982 | unsigned long wait; |
| 983 | |
| 984 | spin_lock_irqsave(&sclp_lock, flags); |
| 985 | /* Check if interface is in appropriate state */ |
| 986 | if (sclp_mask_state != sclp_mask_state_idle) { |
| 987 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 988 | return -EBUSY; |
| 989 | } |
| 990 | if (sclp_activation_state == sclp_activation_state_inactive) { |
| 991 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 992 | return -EINVAL; |
| 993 | } |
| 994 | sclp_mask_state = sclp_mask_state_initializing; |
| 995 | /* Determine mask */ |
| 996 | if (calculate) |
| 997 | __sclp_get_mask(&receive_mask, &send_mask); |
| 998 | else { |
| 999 | receive_mask = 0; |
| 1000 | send_mask = 0; |
| 1001 | } |
| 1002 | rc = -EIO; |
| 1003 | for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { |
| 1004 | /* Prepare request */ |
| 1005 | __sclp_make_init_req(receive_mask, send_mask); |
| 1006 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1007 | if (sclp_add_request(&sclp_init_req)) { |
| 1008 | /* Try again later */ |
| 1009 | wait = jiffies + SCLP_BUSY_INTERVAL * HZ; |
| 1010 | while (time_before(jiffies, wait)) |
| 1011 | sclp_sync_wait(); |
| 1012 | spin_lock_irqsave(&sclp_lock, flags); |
| 1013 | continue; |
| 1014 | } |
| 1015 | while (sclp_init_req.status != SCLP_REQ_DONE && |
| 1016 | sclp_init_req.status != SCLP_REQ_FAILED) |
| 1017 | sclp_sync_wait(); |
| 1018 | spin_lock_irqsave(&sclp_lock, flags); |
| 1019 | if (sclp_init_req.status == SCLP_REQ_DONE && |
| 1020 | sccb->header.response_code == 0x20) { |
| 1021 | /* Successful request */ |
| 1022 | if (calculate) { |
| 1023 | sclp_receive_mask = sccb_get_sclp_recv_mask(sccb); |
| 1024 | sclp_send_mask = sccb_get_sclp_send_mask(sccb); |
| 1025 | } else { |
| 1026 | sclp_receive_mask = 0; |
| 1027 | sclp_send_mask = 0; |
| 1028 | } |
| 1029 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1030 | sclp_dispatch_state_change(); |
| 1031 | spin_lock_irqsave(&sclp_lock, flags); |
| 1032 | rc = 0; |
| 1033 | break; |
| 1034 | } |
| 1035 | } |
| 1036 | sclp_mask_state = sclp_mask_state_idle; |
| 1037 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1038 | return rc; |
| 1039 | } |
| 1040 | |
| 1041 | /* Deactivate SCLP interface. On success, new requests will be rejected, |
| 1042 | * events will no longer be dispatched. Return 0 on success, non-zero |
| 1043 | * otherwise. */ |
| 1044 | int |
| 1045 | sclp_deactivate(void) |
| 1046 | { |
| 1047 | unsigned long flags; |
| 1048 | int rc; |
| 1049 | |
| 1050 | spin_lock_irqsave(&sclp_lock, flags); |
| 1051 | /* Deactivate can only be called when active */ |
| 1052 | if (sclp_activation_state != sclp_activation_state_active) { |
| 1053 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1054 | return -EINVAL; |
| 1055 | } |
| 1056 | sclp_activation_state = sclp_activation_state_deactivating; |
| 1057 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1058 | rc = sclp_init_mask(0); |
| 1059 | spin_lock_irqsave(&sclp_lock, flags); |
| 1060 | if (rc == 0) |
| 1061 | sclp_activation_state = sclp_activation_state_inactive; |
| 1062 | else |
| 1063 | sclp_activation_state = sclp_activation_state_active; |
| 1064 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1065 | return rc; |
| 1066 | } |
| 1067 | |
| 1068 | EXPORT_SYMBOL(sclp_deactivate); |
| 1069 | |
| 1070 | /* Reactivate SCLP interface after sclp_deactivate. On success, new |
| 1071 | * requests will be accepted, events will be dispatched again. Return 0 on |
| 1072 | * success, non-zero otherwise. */ |
| 1073 | int |
| 1074 | sclp_reactivate(void) |
| 1075 | { |
| 1076 | unsigned long flags; |
| 1077 | int rc; |
| 1078 | |
| 1079 | spin_lock_irqsave(&sclp_lock, flags); |
| 1080 | /* Reactivate can only be called when inactive */ |
| 1081 | if (sclp_activation_state != sclp_activation_state_inactive) { |
| 1082 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1083 | return -EINVAL; |
| 1084 | } |
| 1085 | sclp_activation_state = sclp_activation_state_activating; |
| 1086 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1087 | rc = sclp_init_mask(1); |
| 1088 | spin_lock_irqsave(&sclp_lock, flags); |
| 1089 | if (rc == 0) |
| 1090 | sclp_activation_state = sclp_activation_state_active; |
| 1091 | else |
| 1092 | sclp_activation_state = sclp_activation_state_inactive; |
| 1093 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1094 | return rc; |
| 1095 | } |
| 1096 | |
| 1097 | EXPORT_SYMBOL(sclp_reactivate); |
| 1098 | |
| 1099 | /* Handler for external interruption used during initialization. Modify |
| 1100 | * request state to done. */ |
| 1101 | static void sclp_check_handler(struct ext_code ext_code, |
| 1102 | unsigned int param32, unsigned long param64) |
| 1103 | { |
| 1104 | u32 finished_sccb; |
| 1105 | |
| 1106 | inc_irq_stat(IRQEXT_SCP); |
| 1107 | finished_sccb = param32 & 0xfffffff8; |
| 1108 | /* Is this the interrupt we are waiting for? */ |
| 1109 | if (finished_sccb == 0) |
| 1110 | return; |
| 1111 | if (finished_sccb != __pa(sclp_init_sccb)) |
| 1112 | panic("sclp: unsolicited interrupt for buffer at 0x%x\n", |
| 1113 | finished_sccb); |
| 1114 | spin_lock(&sclp_lock); |
| 1115 | if (sclp_running_state == sclp_running_state_running) { |
| 1116 | sclp_init_req.status = SCLP_REQ_DONE; |
| 1117 | sclp_running_state = sclp_running_state_idle; |
| 1118 | } |
| 1119 | spin_unlock(&sclp_lock); |
| 1120 | } |
| 1121 | |
| 1122 | /* Initial init mask request timed out. Modify request state to failed. */ |
| 1123 | static void |
| 1124 | sclp_check_timeout(struct timer_list *unused) |
| 1125 | { |
| 1126 | unsigned long flags; |
| 1127 | |
| 1128 | spin_lock_irqsave(&sclp_lock, flags); |
| 1129 | if (sclp_running_state == sclp_running_state_running) { |
| 1130 | sclp_init_req.status = SCLP_REQ_FAILED; |
| 1131 | sclp_running_state = sclp_running_state_idle; |
| 1132 | } |
| 1133 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1134 | } |
| 1135 | |
| 1136 | /* Perform a check of the SCLP interface. Return zero if the interface is |
| 1137 | * available and there are no pending requests from a previous instance. |
| 1138 | * Return non-zero otherwise. */ |
| 1139 | static int |
| 1140 | sclp_check_interface(void) |
| 1141 | { |
| 1142 | struct init_sccb *sccb; |
| 1143 | unsigned long flags; |
| 1144 | int retry; |
| 1145 | int rc; |
| 1146 | |
| 1147 | spin_lock_irqsave(&sclp_lock, flags); |
| 1148 | /* Prepare init mask command */ |
| 1149 | rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); |
| 1150 | if (rc) { |
| 1151 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1152 | return rc; |
| 1153 | } |
| 1154 | for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { |
| 1155 | __sclp_make_init_req(0, 0); |
| 1156 | sccb = (struct init_sccb *) sclp_init_req.sccb; |
| 1157 | rc = sclp_service_call_trace(sclp_init_req.command, sccb); |
| 1158 | if (rc == -EIO) |
| 1159 | break; |
| 1160 | sclp_init_req.status = SCLP_REQ_RUNNING; |
| 1161 | sclp_running_state = sclp_running_state_running; |
| 1162 | __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, |
| 1163 | sclp_check_timeout); |
| 1164 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1165 | /* Enable service-signal interruption - needs to happen |
| 1166 | * with IRQs enabled. */ |
| 1167 | irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); |
| 1168 | /* Wait for signal from interrupt or timeout */ |
| 1169 | sclp_sync_wait(); |
| 1170 | /* Disable service-signal interruption - needs to happen |
| 1171 | * with IRQs enabled. */ |
| 1172 | irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); |
| 1173 | spin_lock_irqsave(&sclp_lock, flags); |
| 1174 | del_timer(&sclp_request_timer); |
| 1175 | rc = -EBUSY; |
| 1176 | if (sclp_init_req.status == SCLP_REQ_DONE) { |
| 1177 | if (sccb->header.response_code == 0x20) { |
| 1178 | rc = 0; |
| 1179 | break; |
| 1180 | } else if (sccb->header.response_code == 0x74f0) { |
| 1181 | if (!sclp_mask_compat_mode) { |
| 1182 | sclp_mask_compat_mode = true; |
| 1183 | retry = 0; |
| 1184 | } |
| 1185 | } |
| 1186 | } |
| 1187 | } |
| 1188 | unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); |
| 1189 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1190 | return rc; |
| 1191 | } |
| 1192 | |
| 1193 | /* Reboot event handler. Reset send and receive mask to prevent pending SCLP |
| 1194 | * events from interfering with rebooted system. */ |
| 1195 | static int |
| 1196 | sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) |
| 1197 | { |
| 1198 | sclp_deactivate(); |
| 1199 | return NOTIFY_DONE; |
| 1200 | } |
| 1201 | |
| 1202 | static struct notifier_block sclp_reboot_notifier = { |
| 1203 | .notifier_call = sclp_reboot_event |
| 1204 | }; |
| 1205 | |
| 1206 | static ssize_t con_pages_show(struct device_driver *dev, char *buf) |
| 1207 | { |
| 1208 | return sprintf(buf, "%i\n", sclp_console_pages); |
| 1209 | } |
| 1210 | |
| 1211 | static DRIVER_ATTR_RO(con_pages); |
| 1212 | |
| 1213 | static ssize_t con_drop_show(struct device_driver *dev, char *buf) |
| 1214 | { |
| 1215 | return sprintf(buf, "%i\n", sclp_console_drop); |
| 1216 | } |
| 1217 | |
| 1218 | static DRIVER_ATTR_RO(con_drop); |
| 1219 | |
| 1220 | static ssize_t con_full_show(struct device_driver *dev, char *buf) |
| 1221 | { |
| 1222 | return sprintf(buf, "%lu\n", sclp_console_full); |
| 1223 | } |
| 1224 | |
| 1225 | static DRIVER_ATTR_RO(con_full); |
| 1226 | |
| 1227 | static struct attribute *sclp_drv_attrs[] = { |
| 1228 | &driver_attr_con_pages.attr, |
| 1229 | &driver_attr_con_drop.attr, |
| 1230 | &driver_attr_con_full.attr, |
| 1231 | NULL, |
| 1232 | }; |
| 1233 | static struct attribute_group sclp_drv_attr_group = { |
| 1234 | .attrs = sclp_drv_attrs, |
| 1235 | }; |
| 1236 | static const struct attribute_group *sclp_drv_attr_groups[] = { |
| 1237 | &sclp_drv_attr_group, |
| 1238 | NULL, |
| 1239 | }; |
| 1240 | |
| 1241 | static struct platform_driver sclp_pdrv = { |
| 1242 | .driver = { |
| 1243 | .name = "sclp", |
| 1244 | .groups = sclp_drv_attr_groups, |
| 1245 | }, |
| 1246 | }; |
| 1247 | |
| 1248 | /* Initialize SCLP driver. Return zero if driver is operational, non-zero |
| 1249 | * otherwise. */ |
| 1250 | static int |
| 1251 | sclp_init(void) |
| 1252 | { |
| 1253 | unsigned long flags; |
| 1254 | int rc = 0; |
| 1255 | |
| 1256 | spin_lock_irqsave(&sclp_lock, flags); |
| 1257 | /* Check for previous or running initialization */ |
| 1258 | if (sclp_init_state != sclp_init_state_uninitialized) |
| 1259 | goto fail_unlock; |
| 1260 | sclp_init_state = sclp_init_state_initializing; |
| 1261 | sclp_read_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA); |
| 1262 | sclp_init_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA); |
| 1263 | BUG_ON(!sclp_read_sccb || !sclp_init_sccb); |
| 1264 | /* Set up variables */ |
| 1265 | list_add(&sclp_state_change_event.list, &sclp_reg_list); |
| 1266 | timer_setup(&sclp_request_timer, NULL, 0); |
| 1267 | timer_setup(&sclp_queue_timer, sclp_req_queue_timeout, 0); |
| 1268 | /* Check interface */ |
| 1269 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1270 | rc = sclp_check_interface(); |
| 1271 | spin_lock_irqsave(&sclp_lock, flags); |
| 1272 | if (rc) |
| 1273 | goto fail_init_state_uninitialized; |
| 1274 | /* Register reboot handler */ |
| 1275 | rc = register_reboot_notifier(&sclp_reboot_notifier); |
| 1276 | if (rc) |
| 1277 | goto fail_init_state_uninitialized; |
| 1278 | /* Register interrupt handler */ |
| 1279 | rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler); |
| 1280 | if (rc) |
| 1281 | goto fail_unregister_reboot_notifier; |
| 1282 | sclp_init_state = sclp_init_state_initialized; |
| 1283 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1284 | /* Enable service-signal external interruption - needs to happen with |
| 1285 | * IRQs enabled. */ |
| 1286 | irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); |
| 1287 | sclp_init_mask(1); |
| 1288 | return 0; |
| 1289 | |
| 1290 | fail_unregister_reboot_notifier: |
| 1291 | unregister_reboot_notifier(&sclp_reboot_notifier); |
| 1292 | fail_init_state_uninitialized: |
| 1293 | sclp_init_state = sclp_init_state_uninitialized; |
| 1294 | free_page((unsigned long) sclp_read_sccb); |
| 1295 | free_page((unsigned long) sclp_init_sccb); |
| 1296 | fail_unlock: |
| 1297 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 1298 | return rc; |
| 1299 | } |
| 1300 | |
| 1301 | static __init int sclp_initcall(void) |
| 1302 | { |
| 1303 | int rc; |
| 1304 | |
| 1305 | rc = platform_driver_register(&sclp_pdrv); |
| 1306 | if (rc) |
| 1307 | return rc; |
| 1308 | |
| 1309 | return sclp_init(); |
| 1310 | } |
| 1311 | |
| 1312 | arch_initcall(sclp_initcall); |