Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * drivers/s390/char/sclp.c |
| 3 | * core function to access sclp interface |
| 4 | * |
| 5 | * S390 version |
| 6 | * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| 7 | * Author(s): Martin Peschke <mpeschke@de.ibm.com> |
| 8 | * Martin Schwidefsky <schwidefsky@de.ibm.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/err.h> |
| 13 | #include <linux/spinlock.h> |
| 14 | #include <linux/interrupt.h> |
| 15 | #include <linux/timer.h> |
| 16 | #include <linux/reboot.h> |
| 17 | #include <linux/jiffies.h> |
| 18 | #include <asm/types.h> |
| 19 | #include <asm/s390_ext.h> |
| 20 | |
| 21 | #include "sclp.h" |
| 22 | |
| 23 | #define SCLP_HEADER "sclp: " |
| 24 | |
| 25 | /* Structure for register_early_external_interrupt. */ |
| 26 | static ext_int_info_t ext_int_info_hwc; |
| 27 | |
| 28 | /* Lock to protect internal data consistency. */ |
| 29 | static DEFINE_SPINLOCK(sclp_lock); |
| 30 | |
| 31 | /* Mask of events that we can receive from the sclp interface. */ |
| 32 | static sccb_mask_t sclp_receive_mask; |
| 33 | |
| 34 | /* Mask of events that we can send to the sclp interface. */ |
| 35 | static sccb_mask_t sclp_send_mask; |
| 36 | |
| 37 | /* List of registered event listeners and senders. */ |
| 38 | static struct list_head sclp_reg_list; |
| 39 | |
| 40 | /* List of queued requests. */ |
| 41 | static struct list_head sclp_req_queue; |
| 42 | |
| 43 | /* Data for read and and init requests. */ |
| 44 | static struct sclp_req sclp_read_req; |
| 45 | static struct sclp_req sclp_init_req; |
| 46 | static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); |
| 47 | static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); |
| 48 | |
| 49 | /* Timer for request retries. */ |
| 50 | static struct timer_list sclp_request_timer; |
| 51 | |
| 52 | /* Internal state: is the driver initialized? */ |
| 53 | static volatile enum sclp_init_state_t { |
| 54 | sclp_init_state_uninitialized, |
| 55 | sclp_init_state_initializing, |
| 56 | sclp_init_state_initialized |
| 57 | } sclp_init_state = sclp_init_state_uninitialized; |
| 58 | |
| 59 | /* Internal state: is a request active at the sclp? */ |
| 60 | static volatile enum sclp_running_state_t { |
| 61 | sclp_running_state_idle, |
| 62 | sclp_running_state_running |
| 63 | } sclp_running_state = sclp_running_state_idle; |
| 64 | |
| 65 | /* Internal state: is a read request pending? */ |
| 66 | static volatile enum sclp_reading_state_t { |
| 67 | sclp_reading_state_idle, |
| 68 | sclp_reading_state_reading |
| 69 | } sclp_reading_state = sclp_reading_state_idle; |
| 70 | |
| 71 | /* Internal state: is the driver currently serving requests? */ |
| 72 | static volatile enum sclp_activation_state_t { |
| 73 | sclp_activation_state_active, |
| 74 | sclp_activation_state_deactivating, |
| 75 | sclp_activation_state_inactive, |
| 76 | sclp_activation_state_activating |
| 77 | } sclp_activation_state = sclp_activation_state_active; |
| 78 | |
| 79 | /* Internal state: is an init mask request pending? */ |
| 80 | static volatile enum sclp_mask_state_t { |
| 81 | sclp_mask_state_idle, |
| 82 | sclp_mask_state_initializing |
| 83 | } sclp_mask_state = sclp_mask_state_idle; |
| 84 | |
| 85 | /* Maximum retry counts */ |
| 86 | #define SCLP_INIT_RETRY 3 |
| 87 | #define SCLP_MASK_RETRY 3 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
| 89 | /* Timeout intervals in seconds.*/ |
Peter Oberparleiter | 25fab9e | 2006-02-11 17:55:59 -0800 | [diff] [blame] | 90 | #define SCLP_BUSY_INTERVAL 10 |
| 91 | #define SCLP_RETRY_INTERVAL 15 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | |
| 93 | static void sclp_process_queue(void); |
| 94 | static int sclp_init_mask(int calculate); |
| 95 | static int sclp_init(void); |
| 96 | |
| 97 | /* Perform service call. Return 0 on success, non-zero otherwise. */ |
| 98 | static int |
| 99 | service_call(sclp_cmdw_t command, void *sccb) |
| 100 | { |
| 101 | int cc; |
| 102 | |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 103 | asm volatile( |
| 104 | " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ |
| 105 | " ipm %0\n" |
| 106 | " srl %0,28" |
| 107 | : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) |
| 108 | : "cc", "memory"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | if (cc == 3) |
| 110 | return -EIO; |
| 111 | if (cc == 2) |
| 112 | return -EBUSY; |
| 113 | return 0; |
| 114 | } |
| 115 | |
| 116 | /* Request timeout handler. Restart the request queue. If DATA is non-zero, |
| 117 | * force restart of running request. */ |
| 118 | static void |
| 119 | sclp_request_timeout(unsigned long data) |
| 120 | { |
| 121 | unsigned long flags; |
| 122 | |
| 123 | if (data) { |
| 124 | spin_lock_irqsave(&sclp_lock, flags); |
| 125 | sclp_running_state = sclp_running_state_idle; |
| 126 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 127 | } |
| 128 | sclp_process_queue(); |
| 129 | } |
| 130 | |
| 131 | /* Set up request retry timer. Called while sclp_lock is locked. */ |
| 132 | static inline void |
| 133 | __sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), |
| 134 | unsigned long data) |
| 135 | { |
| 136 | del_timer(&sclp_request_timer); |
| 137 | sclp_request_timer.function = function; |
| 138 | sclp_request_timer.data = data; |
| 139 | sclp_request_timer.expires = jiffies + time; |
| 140 | add_timer(&sclp_request_timer); |
| 141 | } |
| 142 | |
| 143 | /* Try to start a request. Return zero if the request was successfully |
| 144 | * started or if it will be started at a later time. Return non-zero otherwise. |
| 145 | * Called while sclp_lock is locked. */ |
| 146 | static int |
| 147 | __sclp_start_request(struct sclp_req *req) |
| 148 | { |
| 149 | int rc; |
| 150 | |
| 151 | if (sclp_running_state != sclp_running_state_idle) |
| 152 | return 0; |
| 153 | del_timer(&sclp_request_timer); |
Peter Oberparleiter | 25fab9e | 2006-02-11 17:55:59 -0800 | [diff] [blame] | 154 | rc = service_call(req->command, req->sccb); |
| 155 | req->start_count++; |
| 156 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | if (rc == 0) { |
| 158 | /* Sucessfully started request */ |
| 159 | req->status = SCLP_REQ_RUNNING; |
| 160 | sclp_running_state = sclp_running_state_running; |
| 161 | __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, |
| 162 | sclp_request_timeout, 1); |
| 163 | return 0; |
| 164 | } else if (rc == -EBUSY) { |
| 165 | /* Try again later */ |
| 166 | __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, |
| 167 | sclp_request_timeout, 0); |
| 168 | return 0; |
| 169 | } |
| 170 | /* Request failed */ |
| 171 | req->status = SCLP_REQ_FAILED; |
| 172 | return rc; |
| 173 | } |
| 174 | |
| 175 | /* Try to start queued requests. */ |
| 176 | static void |
| 177 | sclp_process_queue(void) |
| 178 | { |
| 179 | struct sclp_req *req; |
| 180 | int rc; |
| 181 | unsigned long flags; |
| 182 | |
| 183 | spin_lock_irqsave(&sclp_lock, flags); |
| 184 | if (sclp_running_state != sclp_running_state_idle) { |
| 185 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 186 | return; |
| 187 | } |
| 188 | del_timer(&sclp_request_timer); |
| 189 | while (!list_empty(&sclp_req_queue)) { |
| 190 | req = list_entry(sclp_req_queue.next, struct sclp_req, list); |
| 191 | rc = __sclp_start_request(req); |
| 192 | if (rc == 0) |
| 193 | break; |
| 194 | /* Request failed. */ |
| 195 | list_del(&req->list); |
| 196 | if (req->callback) { |
| 197 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 198 | req->callback(req, req->callback_data); |
| 199 | spin_lock_irqsave(&sclp_lock, flags); |
| 200 | } |
| 201 | } |
| 202 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 203 | } |
| 204 | |
| 205 | /* Queue a new request. Return zero on success, non-zero otherwise. */ |
| 206 | int |
| 207 | sclp_add_request(struct sclp_req *req) |
| 208 | { |
| 209 | unsigned long flags; |
| 210 | int rc; |
| 211 | |
| 212 | spin_lock_irqsave(&sclp_lock, flags); |
| 213 | if ((sclp_init_state != sclp_init_state_initialized || |
| 214 | sclp_activation_state != sclp_activation_state_active) && |
| 215 | req != &sclp_init_req) { |
| 216 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 217 | return -EIO; |
| 218 | } |
| 219 | req->status = SCLP_REQ_QUEUED; |
| 220 | req->start_count = 0; |
| 221 | list_add_tail(&req->list, &sclp_req_queue); |
| 222 | rc = 0; |
| 223 | /* Start if request is first in list */ |
| 224 | if (req->list.prev == &sclp_req_queue) { |
| 225 | rc = __sclp_start_request(req); |
| 226 | if (rc) |
| 227 | list_del(&req->list); |
| 228 | } |
| 229 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 230 | return rc; |
| 231 | } |
| 232 | |
| 233 | EXPORT_SYMBOL(sclp_add_request); |
| 234 | |
| 235 | /* Dispatch events found in request buffer to registered listeners. Return 0 |
| 236 | * if all events were dispatched, non-zero otherwise. */ |
| 237 | static int |
| 238 | sclp_dispatch_evbufs(struct sccb_header *sccb) |
| 239 | { |
| 240 | unsigned long flags; |
| 241 | struct evbuf_header *evbuf; |
| 242 | struct list_head *l; |
| 243 | struct sclp_register *reg; |
| 244 | int offset; |
| 245 | int rc; |
| 246 | |
| 247 | spin_lock_irqsave(&sclp_lock, flags); |
| 248 | rc = 0; |
| 249 | for (offset = sizeof(struct sccb_header); offset < sccb->length; |
| 250 | offset += evbuf->length) { |
| 251 | /* Search for event handler */ |
| 252 | evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); |
| 253 | reg = NULL; |
| 254 | list_for_each(l, &sclp_reg_list) { |
| 255 | reg = list_entry(l, struct sclp_register, list); |
| 256 | if (reg->receive_mask & (1 << (32 - evbuf->type))) |
| 257 | break; |
| 258 | else |
| 259 | reg = NULL; |
| 260 | } |
| 261 | if (reg && reg->receiver_fn) { |
| 262 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 263 | reg->receiver_fn(evbuf); |
| 264 | spin_lock_irqsave(&sclp_lock, flags); |
| 265 | } else if (reg == NULL) |
| 266 | rc = -ENOSYS; |
| 267 | } |
| 268 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 269 | return rc; |
| 270 | } |
| 271 | |
| 272 | /* Read event data request callback. */ |
| 273 | static void |
| 274 | sclp_read_cb(struct sclp_req *req, void *data) |
| 275 | { |
| 276 | unsigned long flags; |
| 277 | struct sccb_header *sccb; |
| 278 | |
| 279 | sccb = (struct sccb_header *) req->sccb; |
| 280 | if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || |
| 281 | sccb->response_code == 0x220)) |
| 282 | sclp_dispatch_evbufs(sccb); |
| 283 | spin_lock_irqsave(&sclp_lock, flags); |
| 284 | sclp_reading_state = sclp_reading_state_idle; |
| 285 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 286 | } |
| 287 | |
| 288 | /* Prepare read event data request. Called while sclp_lock is locked. */ |
| 289 | static inline void |
| 290 | __sclp_make_read_req(void) |
| 291 | { |
| 292 | struct sccb_header *sccb; |
| 293 | |
| 294 | sccb = (struct sccb_header *) sclp_read_sccb; |
| 295 | clear_page(sccb); |
| 296 | memset(&sclp_read_req, 0, sizeof(struct sclp_req)); |
| 297 | sclp_read_req.command = SCLP_CMDW_READDATA; |
| 298 | sclp_read_req.status = SCLP_REQ_QUEUED; |
| 299 | sclp_read_req.start_count = 0; |
| 300 | sclp_read_req.callback = sclp_read_cb; |
| 301 | sclp_read_req.sccb = sccb; |
| 302 | sccb->length = PAGE_SIZE; |
| 303 | sccb->function_code = 0; |
| 304 | sccb->control_mask[2] = 0x80; |
| 305 | } |
| 306 | |
| 307 | /* Search request list for request with matching sccb. Return request if found, |
| 308 | * NULL otherwise. Called while sclp_lock is locked. */ |
| 309 | static inline struct sclp_req * |
| 310 | __sclp_find_req(u32 sccb) |
| 311 | { |
| 312 | struct list_head *l; |
| 313 | struct sclp_req *req; |
| 314 | |
| 315 | list_for_each(l, &sclp_req_queue) { |
| 316 | req = list_entry(l, struct sclp_req, list); |
| 317 | if (sccb == (u32) (addr_t) req->sccb) |
| 318 | return req; |
| 319 | } |
| 320 | return NULL; |
| 321 | } |
| 322 | |
| 323 | /* Handler for external interruption. Perform request post-processing. |
| 324 | * Prepare read event data request if necessary. Start processing of next |
| 325 | * request on queue. */ |
| 326 | static void |
Heiko Carstens | 5a489b9 | 2006-10-06 16:38:35 +0200 | [diff] [blame^] | 327 | sclp_interrupt_handler(__u16 code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | { |
| 329 | struct sclp_req *req; |
| 330 | u32 finished_sccb; |
| 331 | u32 evbuf_pending; |
| 332 | |
| 333 | spin_lock(&sclp_lock); |
| 334 | finished_sccb = S390_lowcore.ext_params & 0xfffffff8; |
| 335 | evbuf_pending = S390_lowcore.ext_params & 0x3; |
| 336 | if (finished_sccb) { |
| 337 | req = __sclp_find_req(finished_sccb); |
| 338 | if (req) { |
| 339 | /* Request post-processing */ |
| 340 | list_del(&req->list); |
| 341 | req->status = SCLP_REQ_DONE; |
| 342 | if (req->callback) { |
| 343 | spin_unlock(&sclp_lock); |
| 344 | req->callback(req, req->callback_data); |
| 345 | spin_lock(&sclp_lock); |
| 346 | } |
| 347 | } |
| 348 | sclp_running_state = sclp_running_state_idle; |
| 349 | } |
| 350 | if (evbuf_pending && sclp_receive_mask != 0 && |
| 351 | sclp_reading_state == sclp_reading_state_idle && |
| 352 | sclp_activation_state == sclp_activation_state_active ) { |
| 353 | sclp_reading_state = sclp_reading_state_reading; |
| 354 | __sclp_make_read_req(); |
| 355 | /* Add request to head of queue */ |
| 356 | list_add(&sclp_read_req.list, &sclp_req_queue); |
| 357 | } |
| 358 | spin_unlock(&sclp_lock); |
| 359 | sclp_process_queue(); |
| 360 | } |
| 361 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | /* Convert interval in jiffies to TOD ticks. */ |
| 363 | static inline u64 |
| 364 | sclp_tod_from_jiffies(unsigned long jiffies) |
| 365 | { |
| 366 | return (u64) (jiffies / HZ) << 32; |
| 367 | } |
| 368 | |
| 369 | /* Wait until a currently running request finished. Note: while this function |
| 370 | * is running, no timers are served on the calling CPU. */ |
| 371 | void |
| 372 | sclp_sync_wait(void) |
| 373 | { |
Heiko Carstens | 1f194a4 | 2006-07-03 00:24:46 -0700 | [diff] [blame] | 374 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | unsigned long cr0, cr0_sync; |
| 376 | u64 timeout; |
| 377 | |
| 378 | /* We'll be disabling timer interrupts, so we need a custom timeout |
| 379 | * mechanism */ |
| 380 | timeout = 0; |
| 381 | if (timer_pending(&sclp_request_timer)) { |
| 382 | /* Get timeout TOD value */ |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 383 | timeout = get_clock() + |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | sclp_tod_from_jiffies(sclp_request_timer.expires - |
| 385 | jiffies); |
| 386 | } |
Heiko Carstens | 1f194a4 | 2006-07-03 00:24:46 -0700 | [diff] [blame] | 387 | local_irq_save(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | /* Prevent bottom half from executing once we force interrupts open */ |
| 389 | local_bh_disable(); |
| 390 | /* Enable service-signal interruption, disable timer interrupts */ |
Heiko Carstens | 1f194a4 | 2006-07-03 00:24:46 -0700 | [diff] [blame] | 391 | trace_hardirqs_on(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | __ctl_store(cr0, 0, 0); |
| 393 | cr0_sync = cr0; |
| 394 | cr0_sync |= 0x00000200; |
| 395 | cr0_sync &= 0xFFFFF3AC; |
| 396 | __ctl_load(cr0_sync, 0, 0); |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 397 | __raw_local_irq_stosm(0x01); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | /* Loop until driver state indicates finished request */ |
| 399 | while (sclp_running_state != sclp_running_state_idle) { |
| 400 | /* Check for expired request timer */ |
| 401 | if (timer_pending(&sclp_request_timer) && |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 402 | get_clock() > timeout && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | del_timer(&sclp_request_timer)) |
| 404 | sclp_request_timer.function(sclp_request_timer.data); |
| 405 | barrier(); |
| 406 | cpu_relax(); |
| 407 | } |
Heiko Carstens | 1f194a4 | 2006-07-03 00:24:46 -0700 | [diff] [blame] | 408 | local_irq_disable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | __ctl_load(cr0, 0, 0); |
Heiko Carstens | 1f194a4 | 2006-07-03 00:24:46 -0700 | [diff] [blame] | 410 | _local_bh_enable(); |
| 411 | local_irq_restore(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | } |
| 413 | |
| 414 | EXPORT_SYMBOL(sclp_sync_wait); |
| 415 | |
| 416 | /* Dispatch changes in send and receive mask to registered listeners. */ |
| 417 | static inline void |
| 418 | sclp_dispatch_state_change(void) |
| 419 | { |
| 420 | struct list_head *l; |
| 421 | struct sclp_register *reg; |
| 422 | unsigned long flags; |
| 423 | sccb_mask_t receive_mask; |
| 424 | sccb_mask_t send_mask; |
| 425 | |
| 426 | do { |
| 427 | spin_lock_irqsave(&sclp_lock, flags); |
| 428 | reg = NULL; |
| 429 | list_for_each(l, &sclp_reg_list) { |
| 430 | reg = list_entry(l, struct sclp_register, list); |
| 431 | receive_mask = reg->receive_mask & sclp_receive_mask; |
| 432 | send_mask = reg->send_mask & sclp_send_mask; |
| 433 | if (reg->sclp_receive_mask != receive_mask || |
| 434 | reg->sclp_send_mask != send_mask) { |
| 435 | reg->sclp_receive_mask = receive_mask; |
| 436 | reg->sclp_send_mask = send_mask; |
| 437 | break; |
| 438 | } else |
| 439 | reg = NULL; |
| 440 | } |
| 441 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 442 | if (reg && reg->state_change_fn) |
| 443 | reg->state_change_fn(reg); |
| 444 | } while (reg); |
| 445 | } |
| 446 | |
| 447 | struct sclp_statechangebuf { |
| 448 | struct evbuf_header header; |
| 449 | u8 validity_sclp_active_facility_mask : 1; |
| 450 | u8 validity_sclp_receive_mask : 1; |
| 451 | u8 validity_sclp_send_mask : 1; |
| 452 | u8 validity_read_data_function_mask : 1; |
| 453 | u16 _zeros : 12; |
| 454 | u16 mask_length; |
| 455 | u64 sclp_active_facility_mask; |
| 456 | sccb_mask_t sclp_receive_mask; |
| 457 | sccb_mask_t sclp_send_mask; |
| 458 | u32 read_data_function_mask; |
| 459 | } __attribute__((packed)); |
| 460 | |
| 461 | |
| 462 | /* State change event callback. Inform listeners of changes. */ |
| 463 | static void |
| 464 | sclp_state_change_cb(struct evbuf_header *evbuf) |
| 465 | { |
| 466 | unsigned long flags; |
| 467 | struct sclp_statechangebuf *scbuf; |
| 468 | |
| 469 | scbuf = (struct sclp_statechangebuf *) evbuf; |
| 470 | if (scbuf->mask_length != sizeof(sccb_mask_t)) |
| 471 | return; |
| 472 | spin_lock_irqsave(&sclp_lock, flags); |
| 473 | if (scbuf->validity_sclp_receive_mask) |
| 474 | sclp_receive_mask = scbuf->sclp_receive_mask; |
| 475 | if (scbuf->validity_sclp_send_mask) |
| 476 | sclp_send_mask = scbuf->sclp_send_mask; |
| 477 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 478 | sclp_dispatch_state_change(); |
| 479 | } |
| 480 | |
| 481 | static struct sclp_register sclp_state_change_event = { |
| 482 | .receive_mask = EvTyp_StateChange_Mask, |
| 483 | .receiver_fn = sclp_state_change_cb |
| 484 | }; |
| 485 | |
| 486 | /* Calculate receive and send mask of currently registered listeners. |
| 487 | * Called while sclp_lock is locked. */ |
| 488 | static inline void |
| 489 | __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) |
| 490 | { |
| 491 | struct list_head *l; |
| 492 | struct sclp_register *t; |
| 493 | |
| 494 | *receive_mask = 0; |
| 495 | *send_mask = 0; |
| 496 | list_for_each(l, &sclp_reg_list) { |
| 497 | t = list_entry(l, struct sclp_register, list); |
| 498 | *receive_mask |= t->receive_mask; |
| 499 | *send_mask |= t->send_mask; |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | /* Register event listener. Return 0 on success, non-zero otherwise. */ |
| 504 | int |
| 505 | sclp_register(struct sclp_register *reg) |
| 506 | { |
| 507 | unsigned long flags; |
| 508 | sccb_mask_t receive_mask; |
| 509 | sccb_mask_t send_mask; |
| 510 | int rc; |
| 511 | |
| 512 | rc = sclp_init(); |
| 513 | if (rc) |
| 514 | return rc; |
| 515 | spin_lock_irqsave(&sclp_lock, flags); |
| 516 | /* Check event mask for collisions */ |
| 517 | __sclp_get_mask(&receive_mask, &send_mask); |
| 518 | if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { |
| 519 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 520 | return -EBUSY; |
| 521 | } |
| 522 | /* Trigger initial state change callback */ |
| 523 | reg->sclp_receive_mask = 0; |
| 524 | reg->sclp_send_mask = 0; |
| 525 | list_add(®->list, &sclp_reg_list); |
| 526 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 527 | rc = sclp_init_mask(1); |
| 528 | if (rc) { |
| 529 | spin_lock_irqsave(&sclp_lock, flags); |
| 530 | list_del(®->list); |
| 531 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 532 | } |
| 533 | return rc; |
| 534 | } |
| 535 | |
| 536 | EXPORT_SYMBOL(sclp_register); |
| 537 | |
| 538 | /* Unregister event listener. */ |
| 539 | void |
| 540 | sclp_unregister(struct sclp_register *reg) |
| 541 | { |
| 542 | unsigned long flags; |
| 543 | |
| 544 | spin_lock_irqsave(&sclp_lock, flags); |
| 545 | list_del(®->list); |
| 546 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 547 | sclp_init_mask(1); |
| 548 | } |
| 549 | |
| 550 | EXPORT_SYMBOL(sclp_unregister); |
| 551 | |
| 552 | /* Remove event buffers which are marked processed. Return the number of |
| 553 | * remaining event buffers. */ |
| 554 | int |
| 555 | sclp_remove_processed(struct sccb_header *sccb) |
| 556 | { |
| 557 | struct evbuf_header *evbuf; |
| 558 | int unprocessed; |
| 559 | u16 remaining; |
| 560 | |
| 561 | evbuf = (struct evbuf_header *) (sccb + 1); |
| 562 | unprocessed = 0; |
| 563 | remaining = sccb->length - sizeof(struct sccb_header); |
| 564 | while (remaining > 0) { |
| 565 | remaining -= evbuf->length; |
| 566 | if (evbuf->flags & 0x80) { |
| 567 | sccb->length -= evbuf->length; |
| 568 | memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), |
| 569 | remaining); |
| 570 | } else { |
| 571 | unprocessed++; |
| 572 | evbuf = (struct evbuf_header *) |
| 573 | ((addr_t) evbuf + evbuf->length); |
| 574 | } |
| 575 | } |
| 576 | return unprocessed; |
| 577 | } |
| 578 | |
| 579 | EXPORT_SYMBOL(sclp_remove_processed); |
| 580 | |
| 581 | struct init_sccb { |
| 582 | struct sccb_header header; |
| 583 | u16 _reserved; |
| 584 | u16 mask_length; |
| 585 | sccb_mask_t receive_mask; |
| 586 | sccb_mask_t send_mask; |
| 587 | sccb_mask_t sclp_send_mask; |
| 588 | sccb_mask_t sclp_receive_mask; |
| 589 | } __attribute__((packed)); |
| 590 | |
| 591 | /* Prepare init mask request. Called while sclp_lock is locked. */ |
| 592 | static inline void |
| 593 | __sclp_make_init_req(u32 receive_mask, u32 send_mask) |
| 594 | { |
| 595 | struct init_sccb *sccb; |
| 596 | |
| 597 | sccb = (struct init_sccb *) sclp_init_sccb; |
| 598 | clear_page(sccb); |
| 599 | memset(&sclp_init_req, 0, sizeof(struct sclp_req)); |
| 600 | sclp_init_req.command = SCLP_CMDW_WRITEMASK; |
| 601 | sclp_init_req.status = SCLP_REQ_FILLED; |
| 602 | sclp_init_req.start_count = 0; |
| 603 | sclp_init_req.callback = NULL; |
| 604 | sclp_init_req.callback_data = NULL; |
| 605 | sclp_init_req.sccb = sccb; |
| 606 | sccb->header.length = sizeof(struct init_sccb); |
| 607 | sccb->mask_length = sizeof(sccb_mask_t); |
| 608 | sccb->receive_mask = receive_mask; |
| 609 | sccb->send_mask = send_mask; |
| 610 | sccb->sclp_receive_mask = 0; |
| 611 | sccb->sclp_send_mask = 0; |
| 612 | } |
| 613 | |
| 614 | /* Start init mask request. If calculate is non-zero, calculate the mask as |
| 615 | * requested by registered listeners. Use zero mask otherwise. Return 0 on |
| 616 | * success, non-zero otherwise. */ |
| 617 | static int |
| 618 | sclp_init_mask(int calculate) |
| 619 | { |
| 620 | unsigned long flags; |
| 621 | struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; |
| 622 | sccb_mask_t receive_mask; |
| 623 | sccb_mask_t send_mask; |
| 624 | int retry; |
| 625 | int rc; |
| 626 | unsigned long wait; |
| 627 | |
| 628 | spin_lock_irqsave(&sclp_lock, flags); |
| 629 | /* Check if interface is in appropriate state */ |
| 630 | if (sclp_mask_state != sclp_mask_state_idle) { |
| 631 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 632 | return -EBUSY; |
| 633 | } |
| 634 | if (sclp_activation_state == sclp_activation_state_inactive) { |
| 635 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 636 | return -EINVAL; |
| 637 | } |
| 638 | sclp_mask_state = sclp_mask_state_initializing; |
| 639 | /* Determine mask */ |
| 640 | if (calculate) |
| 641 | __sclp_get_mask(&receive_mask, &send_mask); |
| 642 | else { |
| 643 | receive_mask = 0; |
| 644 | send_mask = 0; |
| 645 | } |
| 646 | rc = -EIO; |
| 647 | for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { |
| 648 | /* Prepare request */ |
| 649 | __sclp_make_init_req(receive_mask, send_mask); |
| 650 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 651 | if (sclp_add_request(&sclp_init_req)) { |
| 652 | /* Try again later */ |
| 653 | wait = jiffies + SCLP_BUSY_INTERVAL * HZ; |
| 654 | while (time_before(jiffies, wait)) |
| 655 | sclp_sync_wait(); |
| 656 | spin_lock_irqsave(&sclp_lock, flags); |
| 657 | continue; |
| 658 | } |
| 659 | while (sclp_init_req.status != SCLP_REQ_DONE && |
| 660 | sclp_init_req.status != SCLP_REQ_FAILED) |
| 661 | sclp_sync_wait(); |
| 662 | spin_lock_irqsave(&sclp_lock, flags); |
| 663 | if (sclp_init_req.status == SCLP_REQ_DONE && |
| 664 | sccb->header.response_code == 0x20) { |
| 665 | /* Successful request */ |
| 666 | if (calculate) { |
| 667 | sclp_receive_mask = sccb->sclp_receive_mask; |
| 668 | sclp_send_mask = sccb->sclp_send_mask; |
| 669 | } else { |
| 670 | sclp_receive_mask = 0; |
| 671 | sclp_send_mask = 0; |
| 672 | } |
| 673 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 674 | sclp_dispatch_state_change(); |
| 675 | spin_lock_irqsave(&sclp_lock, flags); |
| 676 | rc = 0; |
| 677 | break; |
| 678 | } |
| 679 | } |
| 680 | sclp_mask_state = sclp_mask_state_idle; |
| 681 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 682 | return rc; |
| 683 | } |
| 684 | |
| 685 | /* Deactivate SCLP interface. On success, new requests will be rejected, |
| 686 | * events will no longer be dispatched. Return 0 on success, non-zero |
| 687 | * otherwise. */ |
| 688 | int |
| 689 | sclp_deactivate(void) |
| 690 | { |
| 691 | unsigned long flags; |
| 692 | int rc; |
| 693 | |
| 694 | spin_lock_irqsave(&sclp_lock, flags); |
| 695 | /* Deactivate can only be called when active */ |
| 696 | if (sclp_activation_state != sclp_activation_state_active) { |
| 697 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 698 | return -EINVAL; |
| 699 | } |
| 700 | sclp_activation_state = sclp_activation_state_deactivating; |
| 701 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 702 | rc = sclp_init_mask(0); |
| 703 | spin_lock_irqsave(&sclp_lock, flags); |
| 704 | if (rc == 0) |
| 705 | sclp_activation_state = sclp_activation_state_inactive; |
| 706 | else |
| 707 | sclp_activation_state = sclp_activation_state_active; |
| 708 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 709 | return rc; |
| 710 | } |
| 711 | |
| 712 | EXPORT_SYMBOL(sclp_deactivate); |
| 713 | |
| 714 | /* Reactivate SCLP interface after sclp_deactivate. On success, new |
| 715 | * requests will be accepted, events will be dispatched again. Return 0 on |
| 716 | * success, non-zero otherwise. */ |
| 717 | int |
| 718 | sclp_reactivate(void) |
| 719 | { |
| 720 | unsigned long flags; |
| 721 | int rc; |
| 722 | |
| 723 | spin_lock_irqsave(&sclp_lock, flags); |
| 724 | /* Reactivate can only be called when inactive */ |
| 725 | if (sclp_activation_state != sclp_activation_state_inactive) { |
| 726 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 727 | return -EINVAL; |
| 728 | } |
| 729 | sclp_activation_state = sclp_activation_state_activating; |
| 730 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 731 | rc = sclp_init_mask(1); |
| 732 | spin_lock_irqsave(&sclp_lock, flags); |
| 733 | if (rc == 0) |
| 734 | sclp_activation_state = sclp_activation_state_active; |
| 735 | else |
| 736 | sclp_activation_state = sclp_activation_state_inactive; |
| 737 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 738 | return rc; |
| 739 | } |
| 740 | |
| 741 | EXPORT_SYMBOL(sclp_reactivate); |
| 742 | |
| 743 | /* Handler for external interruption used during initialization. Modify |
| 744 | * request state to done. */ |
| 745 | static void |
Heiko Carstens | 5a489b9 | 2006-10-06 16:38:35 +0200 | [diff] [blame^] | 746 | sclp_check_handler(__u16 code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | { |
| 748 | u32 finished_sccb; |
| 749 | |
| 750 | finished_sccb = S390_lowcore.ext_params & 0xfffffff8; |
| 751 | /* Is this the interrupt we are waiting for? */ |
| 752 | if (finished_sccb == 0) |
| 753 | return; |
| 754 | if (finished_sccb != (u32) (addr_t) sclp_init_sccb) { |
| 755 | printk(KERN_WARNING SCLP_HEADER "unsolicited interrupt " |
| 756 | "for buffer at 0x%x\n", finished_sccb); |
| 757 | return; |
| 758 | } |
| 759 | spin_lock(&sclp_lock); |
| 760 | if (sclp_running_state == sclp_running_state_running) { |
| 761 | sclp_init_req.status = SCLP_REQ_DONE; |
| 762 | sclp_running_state = sclp_running_state_idle; |
| 763 | } |
| 764 | spin_unlock(&sclp_lock); |
| 765 | } |
| 766 | |
| 767 | /* Initial init mask request timed out. Modify request state to failed. */ |
| 768 | static void |
| 769 | sclp_check_timeout(unsigned long data) |
| 770 | { |
| 771 | unsigned long flags; |
| 772 | |
| 773 | spin_lock_irqsave(&sclp_lock, flags); |
| 774 | if (sclp_running_state == sclp_running_state_running) { |
| 775 | sclp_init_req.status = SCLP_REQ_FAILED; |
| 776 | sclp_running_state = sclp_running_state_idle; |
| 777 | } |
| 778 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 779 | } |
| 780 | |
| 781 | /* Perform a check of the SCLP interface. Return zero if the interface is |
| 782 | * available and there are no pending requests from a previous instance. |
| 783 | * Return non-zero otherwise. */ |
| 784 | static int |
| 785 | sclp_check_interface(void) |
| 786 | { |
| 787 | struct init_sccb *sccb; |
| 788 | unsigned long flags; |
| 789 | int retry; |
| 790 | int rc; |
| 791 | |
| 792 | spin_lock_irqsave(&sclp_lock, flags); |
| 793 | /* Prepare init mask command */ |
| 794 | rc = register_early_external_interrupt(0x2401, sclp_check_handler, |
| 795 | &ext_int_info_hwc); |
| 796 | if (rc) { |
| 797 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 798 | return rc; |
| 799 | } |
| 800 | for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { |
| 801 | __sclp_make_init_req(0, 0); |
| 802 | sccb = (struct init_sccb *) sclp_init_req.sccb; |
| 803 | rc = service_call(sclp_init_req.command, sccb); |
| 804 | if (rc == -EIO) |
| 805 | break; |
| 806 | sclp_init_req.status = SCLP_REQ_RUNNING; |
| 807 | sclp_running_state = sclp_running_state_running; |
| 808 | __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, |
| 809 | sclp_check_timeout, 0); |
| 810 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 811 | /* Enable service-signal interruption - needs to happen |
| 812 | * with IRQs enabled. */ |
| 813 | ctl_set_bit(0, 9); |
| 814 | /* Wait for signal from interrupt or timeout */ |
| 815 | sclp_sync_wait(); |
| 816 | /* Disable service-signal interruption - needs to happen |
| 817 | * with IRQs enabled. */ |
| 818 | ctl_clear_bit(0,9); |
| 819 | spin_lock_irqsave(&sclp_lock, flags); |
| 820 | del_timer(&sclp_request_timer); |
| 821 | if (sclp_init_req.status == SCLP_REQ_DONE && |
| 822 | sccb->header.response_code == 0x20) { |
| 823 | rc = 0; |
| 824 | break; |
| 825 | } else |
| 826 | rc = -EBUSY; |
| 827 | } |
| 828 | unregister_early_external_interrupt(0x2401, sclp_check_handler, |
| 829 | &ext_int_info_hwc); |
| 830 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 831 | return rc; |
| 832 | } |
| 833 | |
| 834 | /* Reboot event handler. Reset send and receive mask to prevent pending SCLP |
| 835 | * events from interfering with rebooted system. */ |
| 836 | static int |
| 837 | sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) |
| 838 | { |
| 839 | sclp_deactivate(); |
| 840 | return NOTIFY_DONE; |
| 841 | } |
| 842 | |
| 843 | static struct notifier_block sclp_reboot_notifier = { |
| 844 | .notifier_call = sclp_reboot_event |
| 845 | }; |
| 846 | |
| 847 | /* Initialize SCLP driver. Return zero if driver is operational, non-zero |
| 848 | * otherwise. */ |
| 849 | static int |
| 850 | sclp_init(void) |
| 851 | { |
| 852 | unsigned long flags; |
| 853 | int rc; |
| 854 | |
| 855 | if (!MACHINE_HAS_SCLP) |
| 856 | return -ENODEV; |
| 857 | spin_lock_irqsave(&sclp_lock, flags); |
| 858 | /* Check for previous or running initialization */ |
| 859 | if (sclp_init_state != sclp_init_state_uninitialized) { |
| 860 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 861 | return 0; |
| 862 | } |
| 863 | sclp_init_state = sclp_init_state_initializing; |
| 864 | /* Set up variables */ |
| 865 | INIT_LIST_HEAD(&sclp_req_queue); |
| 866 | INIT_LIST_HEAD(&sclp_reg_list); |
| 867 | list_add(&sclp_state_change_event.list, &sclp_reg_list); |
| 868 | init_timer(&sclp_request_timer); |
| 869 | /* Check interface */ |
| 870 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 871 | rc = sclp_check_interface(); |
| 872 | spin_lock_irqsave(&sclp_lock, flags); |
| 873 | if (rc) { |
| 874 | sclp_init_state = sclp_init_state_uninitialized; |
| 875 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 876 | return rc; |
| 877 | } |
| 878 | /* Register reboot handler */ |
| 879 | rc = register_reboot_notifier(&sclp_reboot_notifier); |
| 880 | if (rc) { |
| 881 | sclp_init_state = sclp_init_state_uninitialized; |
| 882 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 883 | return rc; |
| 884 | } |
| 885 | /* Register interrupt handler */ |
| 886 | rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler, |
| 887 | &ext_int_info_hwc); |
| 888 | if (rc) { |
| 889 | unregister_reboot_notifier(&sclp_reboot_notifier); |
| 890 | sclp_init_state = sclp_init_state_uninitialized; |
| 891 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 892 | return rc; |
| 893 | } |
| 894 | sclp_init_state = sclp_init_state_initialized; |
| 895 | spin_unlock_irqrestore(&sclp_lock, flags); |
| 896 | /* Enable service-signal external interruption - needs to happen with |
| 897 | * IRQs enabled. */ |
| 898 | ctl_set_bit(0, 9); |
| 899 | sclp_init_mask(1); |
| 900 | return 0; |
| 901 | } |