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Commit | Line | Data |
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1da177e4 LT |
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> | |
b3d00c3b | 18 | #include <linux/init.h> |
1da177e4 LT |
19 | #include <asm/types.h> |
20 | #include <asm/s390_ext.h> | |
21 | ||
22 | #include "sclp.h" | |
23 | ||
24 | #define SCLP_HEADER "sclp: " | |
25 | ||
26 | /* Structure for register_early_external_interrupt. */ | |
27 | static ext_int_info_t ext_int_info_hwc; | |
28 | ||
29 | /* Lock to protect internal data consistency. */ | |
30 | static DEFINE_SPINLOCK(sclp_lock); | |
31 | ||
d082d3ce | 32 | /* Mask of events that we can send to the sclp interface. */ |
1da177e4 LT |
33 | static sccb_mask_t sclp_receive_mask; |
34 | ||
d082d3ce | 35 | /* Mask of events that we can receive from the sclp interface. */ |
1da177e4 LT |
36 | static sccb_mask_t sclp_send_mask; |
37 | ||
38 | /* List of registered event listeners and senders. */ | |
39 | static struct list_head sclp_reg_list; | |
40 | ||
41 | /* List of queued requests. */ | |
42 | static struct list_head sclp_req_queue; | |
43 | ||
44 | /* Data for read and and init requests. */ | |
45 | static struct sclp_req sclp_read_req; | |
46 | static struct sclp_req sclp_init_req; | |
47 | static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); | |
48 | static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); | |
49 | ||
50 | /* Timer for request retries. */ | |
51 | static struct timer_list sclp_request_timer; | |
52 | ||
53 | /* Internal state: is the driver initialized? */ | |
54 | static volatile enum sclp_init_state_t { | |
55 | sclp_init_state_uninitialized, | |
56 | sclp_init_state_initializing, | |
57 | sclp_init_state_initialized | |
58 | } sclp_init_state = sclp_init_state_uninitialized; | |
59 | ||
60 | /* Internal state: is a request active at the sclp? */ | |
61 | static volatile enum sclp_running_state_t { | |
62 | sclp_running_state_idle, | |
dbd8ae63 PO |
63 | sclp_running_state_running, |
64 | sclp_running_state_reset_pending | |
1da177e4 LT |
65 | } sclp_running_state = sclp_running_state_idle; |
66 | ||
67 | /* Internal state: is a read request pending? */ | |
68 | static volatile enum sclp_reading_state_t { | |
69 | sclp_reading_state_idle, | |
70 | sclp_reading_state_reading | |
71 | } sclp_reading_state = sclp_reading_state_idle; | |
72 | ||
73 | /* Internal state: is the driver currently serving requests? */ | |
74 | static volatile enum sclp_activation_state_t { | |
75 | sclp_activation_state_active, | |
76 | sclp_activation_state_deactivating, | |
77 | sclp_activation_state_inactive, | |
78 | sclp_activation_state_activating | |
79 | } sclp_activation_state = sclp_activation_state_active; | |
80 | ||
81 | /* Internal state: is an init mask request pending? */ | |
82 | static volatile enum sclp_mask_state_t { | |
83 | sclp_mask_state_idle, | |
84 | sclp_mask_state_initializing | |
85 | } sclp_mask_state = sclp_mask_state_idle; | |
86 | ||
87 | /* Maximum retry counts */ | |
88 | #define SCLP_INIT_RETRY 3 | |
89 | #define SCLP_MASK_RETRY 3 | |
1da177e4 LT |
90 | |
91 | /* Timeout intervals in seconds.*/ | |
25fab9eb | 92 | #define SCLP_BUSY_INTERVAL 10 |
dbd8ae63 | 93 | #define SCLP_RETRY_INTERVAL 30 |
1da177e4 LT |
94 | |
95 | static void sclp_process_queue(void); | |
364c8558 | 96 | static void __sclp_make_read_req(void); |
1da177e4 LT |
97 | static int sclp_init_mask(int calculate); |
98 | static int sclp_init(void); | |
99 | ||
100 | /* Perform service call. Return 0 on success, non-zero otherwise. */ | |
ab14de6c HC |
101 | int |
102 | sclp_service_call(sclp_cmdw_t command, void *sccb) | |
1da177e4 LT |
103 | { |
104 | int cc; | |
105 | ||
94c12cc7 MS |
106 | asm volatile( |
107 | " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ | |
108 | " ipm %0\n" | |
109 | " srl %0,28" | |
110 | : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) | |
111 | : "cc", "memory"); | |
1da177e4 LT |
112 | if (cc == 3) |
113 | return -EIO; | |
114 | if (cc == 2) | |
115 | return -EBUSY; | |
116 | return 0; | |
117 | } | |
118 | ||
dbd8ae63 | 119 | |
1da177e4 | 120 | static void |
dbd8ae63 | 121 | __sclp_queue_read_req(void) |
1da177e4 | 122 | { |
dbd8ae63 PO |
123 | if (sclp_reading_state == sclp_reading_state_idle) { |
124 | sclp_reading_state = sclp_reading_state_reading; | |
125 | __sclp_make_read_req(); | |
126 | /* Add request to head of queue */ | |
127 | list_add(&sclp_read_req.list, &sclp_req_queue); | |
1da177e4 | 128 | } |
1da177e4 LT |
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 | ||
dbd8ae63 PO |
143 | /* Request timeout handler. Restart the request queue. If DATA is non-zero, |
144 | * force restart of running request. */ | |
145 | static void | |
146 | sclp_request_timeout(unsigned long data) | |
147 | { | |
148 | unsigned long flags; | |
149 | ||
150 | spin_lock_irqsave(&sclp_lock, flags); | |
151 | if (data) { | |
152 | if (sclp_running_state == sclp_running_state_running) { | |
153 | /* Break running state and queue NOP read event request | |
154 | * to get a defined interface state. */ | |
155 | __sclp_queue_read_req(); | |
156 | sclp_running_state = sclp_running_state_idle; | |
157 | } | |
158 | } else { | |
159 | __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, | |
160 | sclp_request_timeout, 0); | |
161 | } | |
162 | spin_unlock_irqrestore(&sclp_lock, flags); | |
163 | sclp_process_queue(); | |
164 | } | |
165 | ||
1da177e4 LT |
166 | /* Try to start a request. Return zero if the request was successfully |
167 | * started or if it will be started at a later time. Return non-zero otherwise. | |
168 | * Called while sclp_lock is locked. */ | |
169 | static int | |
170 | __sclp_start_request(struct sclp_req *req) | |
171 | { | |
172 | int rc; | |
173 | ||
174 | if (sclp_running_state != sclp_running_state_idle) | |
175 | return 0; | |
176 | del_timer(&sclp_request_timer); | |
ab14de6c | 177 | rc = sclp_service_call(req->command, req->sccb); |
25fab9eb PO |
178 | req->start_count++; |
179 | ||
1da177e4 LT |
180 | if (rc == 0) { |
181 | /* Sucessfully started request */ | |
182 | req->status = SCLP_REQ_RUNNING; | |
183 | sclp_running_state = sclp_running_state_running; | |
184 | __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, | |
185 | sclp_request_timeout, 1); | |
186 | return 0; | |
187 | } else if (rc == -EBUSY) { | |
188 | /* Try again later */ | |
189 | __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, | |
190 | sclp_request_timeout, 0); | |
191 | return 0; | |
192 | } | |
193 | /* Request failed */ | |
194 | req->status = SCLP_REQ_FAILED; | |
195 | return rc; | |
196 | } | |
197 | ||
198 | /* Try to start queued requests. */ | |
199 | static void | |
200 | sclp_process_queue(void) | |
201 | { | |
202 | struct sclp_req *req; | |
203 | int rc; | |
204 | unsigned long flags; | |
205 | ||
206 | spin_lock_irqsave(&sclp_lock, flags); | |
207 | if (sclp_running_state != sclp_running_state_idle) { | |
208 | spin_unlock_irqrestore(&sclp_lock, flags); | |
209 | return; | |
210 | } | |
211 | del_timer(&sclp_request_timer); | |
212 | while (!list_empty(&sclp_req_queue)) { | |
213 | req = list_entry(sclp_req_queue.next, struct sclp_req, list); | |
214 | rc = __sclp_start_request(req); | |
215 | if (rc == 0) | |
216 | break; | |
dbd8ae63 PO |
217 | /* Request failed */ |
218 | if (req->start_count > 1) { | |
219 | /* Cannot abort already submitted request - could still | |
220 | * be active at the SCLP */ | |
221 | __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, | |
222 | sclp_request_timeout, 0); | |
223 | break; | |
224 | } | |
225 | /* Post-processing for aborted request */ | |
1da177e4 LT |
226 | list_del(&req->list); |
227 | if (req->callback) { | |
228 | spin_unlock_irqrestore(&sclp_lock, flags); | |
229 | req->callback(req, req->callback_data); | |
230 | spin_lock_irqsave(&sclp_lock, flags); | |
231 | } | |
232 | } | |
233 | spin_unlock_irqrestore(&sclp_lock, flags); | |
234 | } | |
235 | ||
236 | /* Queue a new request. Return zero on success, non-zero otherwise. */ | |
237 | int | |
238 | sclp_add_request(struct sclp_req *req) | |
239 | { | |
240 | unsigned long flags; | |
241 | int rc; | |
242 | ||
243 | spin_lock_irqsave(&sclp_lock, flags); | |
244 | if ((sclp_init_state != sclp_init_state_initialized || | |
245 | sclp_activation_state != sclp_activation_state_active) && | |
246 | req != &sclp_init_req) { | |
247 | spin_unlock_irqrestore(&sclp_lock, flags); | |
248 | return -EIO; | |
249 | } | |
250 | req->status = SCLP_REQ_QUEUED; | |
251 | req->start_count = 0; | |
252 | list_add_tail(&req->list, &sclp_req_queue); | |
253 | rc = 0; | |
254 | /* Start if request is first in list */ | |
dbd8ae63 PO |
255 | if (sclp_running_state == sclp_running_state_idle && |
256 | req->list.prev == &sclp_req_queue) { | |
1da177e4 LT |
257 | rc = __sclp_start_request(req); |
258 | if (rc) | |
259 | list_del(&req->list); | |
260 | } | |
261 | spin_unlock_irqrestore(&sclp_lock, flags); | |
262 | return rc; | |
263 | } | |
264 | ||
265 | EXPORT_SYMBOL(sclp_add_request); | |
266 | ||
267 | /* Dispatch events found in request buffer to registered listeners. Return 0 | |
268 | * if all events were dispatched, non-zero otherwise. */ | |
269 | static int | |
270 | sclp_dispatch_evbufs(struct sccb_header *sccb) | |
271 | { | |
272 | unsigned long flags; | |
273 | struct evbuf_header *evbuf; | |
274 | struct list_head *l; | |
275 | struct sclp_register *reg; | |
276 | int offset; | |
277 | int rc; | |
278 | ||
279 | spin_lock_irqsave(&sclp_lock, flags); | |
280 | rc = 0; | |
281 | for (offset = sizeof(struct sccb_header); offset < sccb->length; | |
282 | offset += evbuf->length) { | |
1da177e4 | 283 | evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); |
e2e5a0f2 PO |
284 | /* Check for malformed hardware response */ |
285 | if (evbuf->length == 0) | |
286 | break; | |
287 | /* Search for event handler */ | |
1da177e4 LT |
288 | reg = NULL; |
289 | list_for_each(l, &sclp_reg_list) { | |
290 | reg = list_entry(l, struct sclp_register, list); | |
291 | if (reg->receive_mask & (1 << (32 - evbuf->type))) | |
292 | break; | |
293 | else | |
294 | reg = NULL; | |
295 | } | |
296 | if (reg && reg->receiver_fn) { | |
297 | spin_unlock_irqrestore(&sclp_lock, flags); | |
298 | reg->receiver_fn(evbuf); | |
299 | spin_lock_irqsave(&sclp_lock, flags); | |
300 | } else if (reg == NULL) | |
301 | rc = -ENOSYS; | |
302 | } | |
303 | spin_unlock_irqrestore(&sclp_lock, flags); | |
304 | return rc; | |
305 | } | |
306 | ||
307 | /* Read event data request callback. */ | |
308 | static void | |
309 | sclp_read_cb(struct sclp_req *req, void *data) | |
310 | { | |
311 | unsigned long flags; | |
312 | struct sccb_header *sccb; | |
313 | ||
314 | sccb = (struct sccb_header *) req->sccb; | |
315 | if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || | |
316 | sccb->response_code == 0x220)) | |
317 | sclp_dispatch_evbufs(sccb); | |
318 | spin_lock_irqsave(&sclp_lock, flags); | |
319 | sclp_reading_state = sclp_reading_state_idle; | |
320 | spin_unlock_irqrestore(&sclp_lock, flags); | |
321 | } | |
322 | ||
323 | /* Prepare read event data request. Called while sclp_lock is locked. */ | |
364c8558 | 324 | static void __sclp_make_read_req(void) |
1da177e4 LT |
325 | { |
326 | struct sccb_header *sccb; | |
327 | ||
328 | sccb = (struct sccb_header *) sclp_read_sccb; | |
329 | clear_page(sccb); | |
330 | memset(&sclp_read_req, 0, sizeof(struct sclp_req)); | |
ab14de6c | 331 | sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; |
1da177e4 LT |
332 | sclp_read_req.status = SCLP_REQ_QUEUED; |
333 | sclp_read_req.start_count = 0; | |
334 | sclp_read_req.callback = sclp_read_cb; | |
335 | sclp_read_req.sccb = sccb; | |
336 | sccb->length = PAGE_SIZE; | |
337 | sccb->function_code = 0; | |
338 | sccb->control_mask[2] = 0x80; | |
339 | } | |
340 | ||
341 | /* Search request list for request with matching sccb. Return request if found, | |
342 | * NULL otherwise. Called while sclp_lock is locked. */ | |
343 | static inline struct sclp_req * | |
344 | __sclp_find_req(u32 sccb) | |
345 | { | |
346 | struct list_head *l; | |
347 | struct sclp_req *req; | |
348 | ||
349 | list_for_each(l, &sclp_req_queue) { | |
350 | req = list_entry(l, struct sclp_req, list); | |
351 | if (sccb == (u32) (addr_t) req->sccb) | |
352 | return req; | |
353 | } | |
354 | return NULL; | |
355 | } | |
356 | ||
357 | /* Handler for external interruption. Perform request post-processing. | |
358 | * Prepare read event data request if necessary. Start processing of next | |
359 | * request on queue. */ | |
360 | static void | |
5a489b98 | 361 | sclp_interrupt_handler(__u16 code) |
1da177e4 LT |
362 | { |
363 | struct sclp_req *req; | |
364 | u32 finished_sccb; | |
365 | u32 evbuf_pending; | |
366 | ||
367 | spin_lock(&sclp_lock); | |
368 | finished_sccb = S390_lowcore.ext_params & 0xfffffff8; | |
369 | evbuf_pending = S390_lowcore.ext_params & 0x3; | |
370 | if (finished_sccb) { | |
dbd8ae63 PO |
371 | del_timer(&sclp_request_timer); |
372 | sclp_running_state = sclp_running_state_reset_pending; | |
1da177e4 LT |
373 | req = __sclp_find_req(finished_sccb); |
374 | if (req) { | |
375 | /* Request post-processing */ | |
376 | list_del(&req->list); | |
377 | req->status = SCLP_REQ_DONE; | |
378 | if (req->callback) { | |
379 | spin_unlock(&sclp_lock); | |
380 | req->callback(req, req->callback_data); | |
381 | spin_lock(&sclp_lock); | |
382 | } | |
383 | } | |
384 | sclp_running_state = sclp_running_state_idle; | |
385 | } | |
d082d3ce | 386 | if (evbuf_pending && |
dbd8ae63 PO |
387 | sclp_activation_state == sclp_activation_state_active) |
388 | __sclp_queue_read_req(); | |
1da177e4 LT |
389 | spin_unlock(&sclp_lock); |
390 | sclp_process_queue(); | |
391 | } | |
392 | ||
1da177e4 LT |
393 | /* Convert interval in jiffies to TOD ticks. */ |
394 | static inline u64 | |
395 | sclp_tod_from_jiffies(unsigned long jiffies) | |
396 | { | |
397 | return (u64) (jiffies / HZ) << 32; | |
398 | } | |
399 | ||
400 | /* Wait until a currently running request finished. Note: while this function | |
401 | * is running, no timers are served on the calling CPU. */ | |
402 | void | |
403 | sclp_sync_wait(void) | |
404 | { | |
934b2857 | 405 | unsigned long long old_tick; |
1f194a4c | 406 | unsigned long flags; |
1da177e4 LT |
407 | unsigned long cr0, cr0_sync; |
408 | u64 timeout; | |
c59d744b | 409 | int irq_context; |
1da177e4 LT |
410 | |
411 | /* We'll be disabling timer interrupts, so we need a custom timeout | |
412 | * mechanism */ | |
413 | timeout = 0; | |
414 | if (timer_pending(&sclp_request_timer)) { | |
415 | /* Get timeout TOD value */ | |
94c12cc7 | 416 | timeout = get_clock() + |
1da177e4 LT |
417 | sclp_tod_from_jiffies(sclp_request_timer.expires - |
418 | jiffies); | |
419 | } | |
1f194a4c | 420 | local_irq_save(flags); |
1da177e4 | 421 | /* Prevent bottom half from executing once we force interrupts open */ |
c59d744b HC |
422 | irq_context = in_interrupt(); |
423 | if (!irq_context) | |
424 | local_bh_disable(); | |
1da177e4 | 425 | /* Enable service-signal interruption, disable timer interrupts */ |
934b2857 | 426 | old_tick = local_tick_disable(); |
1f194a4c | 427 | trace_hardirqs_on(); |
1da177e4 LT |
428 | __ctl_store(cr0, 0, 0); |
429 | cr0_sync = cr0; | |
934b2857 | 430 | cr0_sync &= 0xffff00a0; |
1da177e4 | 431 | cr0_sync |= 0x00000200; |
1da177e4 | 432 | __ctl_load(cr0_sync, 0, 0); |
94c12cc7 | 433 | __raw_local_irq_stosm(0x01); |
1da177e4 LT |
434 | /* Loop until driver state indicates finished request */ |
435 | while (sclp_running_state != sclp_running_state_idle) { | |
436 | /* Check for expired request timer */ | |
437 | if (timer_pending(&sclp_request_timer) && | |
94c12cc7 | 438 | get_clock() > timeout && |
1da177e4 LT |
439 | del_timer(&sclp_request_timer)) |
440 | sclp_request_timer.function(sclp_request_timer.data); | |
1da177e4 LT |
441 | cpu_relax(); |
442 | } | |
1f194a4c | 443 | local_irq_disable(); |
1da177e4 | 444 | __ctl_load(cr0, 0, 0); |
c59d744b HC |
445 | if (!irq_context) |
446 | _local_bh_enable(); | |
934b2857 | 447 | local_tick_enable(old_tick); |
1f194a4c | 448 | local_irq_restore(flags); |
1da177e4 | 449 | } |
1da177e4 LT |
450 | EXPORT_SYMBOL(sclp_sync_wait); |
451 | ||
452 | /* Dispatch changes in send and receive mask to registered listeners. */ | |
4d284cac | 453 | static void |
1da177e4 LT |
454 | sclp_dispatch_state_change(void) |
455 | { | |
456 | struct list_head *l; | |
457 | struct sclp_register *reg; | |
458 | unsigned long flags; | |
459 | sccb_mask_t receive_mask; | |
460 | sccb_mask_t send_mask; | |
461 | ||
462 | do { | |
463 | spin_lock_irqsave(&sclp_lock, flags); | |
464 | reg = NULL; | |
465 | list_for_each(l, &sclp_reg_list) { | |
466 | reg = list_entry(l, struct sclp_register, list); | |
d082d3ce PO |
467 | receive_mask = reg->send_mask & sclp_receive_mask; |
468 | send_mask = reg->receive_mask & sclp_send_mask; | |
1da177e4 LT |
469 | if (reg->sclp_receive_mask != receive_mask || |
470 | reg->sclp_send_mask != send_mask) { | |
471 | reg->sclp_receive_mask = receive_mask; | |
472 | reg->sclp_send_mask = send_mask; | |
473 | break; | |
474 | } else | |
475 | reg = NULL; | |
476 | } | |
477 | spin_unlock_irqrestore(&sclp_lock, flags); | |
478 | if (reg && reg->state_change_fn) | |
479 | reg->state_change_fn(reg); | |
480 | } while (reg); | |
481 | } | |
482 | ||
483 | struct sclp_statechangebuf { | |
484 | struct evbuf_header header; | |
485 | u8 validity_sclp_active_facility_mask : 1; | |
486 | u8 validity_sclp_receive_mask : 1; | |
487 | u8 validity_sclp_send_mask : 1; | |
488 | u8 validity_read_data_function_mask : 1; | |
489 | u16 _zeros : 12; | |
490 | u16 mask_length; | |
491 | u64 sclp_active_facility_mask; | |
492 | sccb_mask_t sclp_receive_mask; | |
493 | sccb_mask_t sclp_send_mask; | |
494 | u32 read_data_function_mask; | |
495 | } __attribute__((packed)); | |
496 | ||
497 | ||
498 | /* State change event callback. Inform listeners of changes. */ | |
499 | static void | |
500 | sclp_state_change_cb(struct evbuf_header *evbuf) | |
501 | { | |
502 | unsigned long flags; | |
503 | struct sclp_statechangebuf *scbuf; | |
504 | ||
505 | scbuf = (struct sclp_statechangebuf *) evbuf; | |
506 | if (scbuf->mask_length != sizeof(sccb_mask_t)) | |
507 | return; | |
508 | spin_lock_irqsave(&sclp_lock, flags); | |
509 | if (scbuf->validity_sclp_receive_mask) | |
510 | sclp_receive_mask = scbuf->sclp_receive_mask; | |
511 | if (scbuf->validity_sclp_send_mask) | |
512 | sclp_send_mask = scbuf->sclp_send_mask; | |
513 | spin_unlock_irqrestore(&sclp_lock, flags); | |
887d935a HC |
514 | if (scbuf->validity_sclp_active_facility_mask) |
515 | sclp_facilities = scbuf->sclp_active_facility_mask; | |
1da177e4 LT |
516 | sclp_dispatch_state_change(); |
517 | } | |
518 | ||
519 | static struct sclp_register sclp_state_change_event = { | |
6d4740c8 | 520 | .receive_mask = EVTYP_STATECHANGE_MASK, |
1da177e4 LT |
521 | .receiver_fn = sclp_state_change_cb |
522 | }; | |
523 | ||
524 | /* Calculate receive and send mask of currently registered listeners. | |
525 | * Called while sclp_lock is locked. */ | |
526 | static inline void | |
527 | __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) | |
528 | { | |
529 | struct list_head *l; | |
530 | struct sclp_register *t; | |
531 | ||
532 | *receive_mask = 0; | |
533 | *send_mask = 0; | |
534 | list_for_each(l, &sclp_reg_list) { | |
535 | t = list_entry(l, struct sclp_register, list); | |
536 | *receive_mask |= t->receive_mask; | |
537 | *send_mask |= t->send_mask; | |
538 | } | |
539 | } | |
540 | ||
541 | /* Register event listener. Return 0 on success, non-zero otherwise. */ | |
542 | int | |
543 | sclp_register(struct sclp_register *reg) | |
544 | { | |
545 | unsigned long flags; | |
546 | sccb_mask_t receive_mask; | |
547 | sccb_mask_t send_mask; | |
548 | int rc; | |
549 | ||
550 | rc = sclp_init(); | |
551 | if (rc) | |
552 | return rc; | |
553 | spin_lock_irqsave(&sclp_lock, flags); | |
554 | /* Check event mask for collisions */ | |
555 | __sclp_get_mask(&receive_mask, &send_mask); | |
556 | if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { | |
557 | spin_unlock_irqrestore(&sclp_lock, flags); | |
558 | return -EBUSY; | |
559 | } | |
560 | /* Trigger initial state change callback */ | |
561 | reg->sclp_receive_mask = 0; | |
562 | reg->sclp_send_mask = 0; | |
563 | list_add(®->list, &sclp_reg_list); | |
564 | spin_unlock_irqrestore(&sclp_lock, flags); | |
565 | rc = sclp_init_mask(1); | |
566 | if (rc) { | |
567 | spin_lock_irqsave(&sclp_lock, flags); | |
568 | list_del(®->list); | |
569 | spin_unlock_irqrestore(&sclp_lock, flags); | |
570 | } | |
571 | return rc; | |
572 | } | |
573 | ||
574 | EXPORT_SYMBOL(sclp_register); | |
575 | ||
576 | /* Unregister event listener. */ | |
577 | void | |
578 | sclp_unregister(struct sclp_register *reg) | |
579 | { | |
580 | unsigned long flags; | |
581 | ||
582 | spin_lock_irqsave(&sclp_lock, flags); | |
583 | list_del(®->list); | |
584 | spin_unlock_irqrestore(&sclp_lock, flags); | |
585 | sclp_init_mask(1); | |
586 | } | |
587 | ||
588 | EXPORT_SYMBOL(sclp_unregister); | |
589 | ||
590 | /* Remove event buffers which are marked processed. Return the number of | |
591 | * remaining event buffers. */ | |
592 | int | |
593 | sclp_remove_processed(struct sccb_header *sccb) | |
594 | { | |
595 | struct evbuf_header *evbuf; | |
596 | int unprocessed; | |
597 | u16 remaining; | |
598 | ||
599 | evbuf = (struct evbuf_header *) (sccb + 1); | |
600 | unprocessed = 0; | |
601 | remaining = sccb->length - sizeof(struct sccb_header); | |
602 | while (remaining > 0) { | |
603 | remaining -= evbuf->length; | |
604 | if (evbuf->flags & 0x80) { | |
605 | sccb->length -= evbuf->length; | |
606 | memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), | |
607 | remaining); | |
608 | } else { | |
609 | unprocessed++; | |
610 | evbuf = (struct evbuf_header *) | |
611 | ((addr_t) evbuf + evbuf->length); | |
612 | } | |
613 | } | |
614 | return unprocessed; | |
615 | } | |
616 | ||
617 | EXPORT_SYMBOL(sclp_remove_processed); | |
618 | ||
619 | struct init_sccb { | |
620 | struct sccb_header header; | |
621 | u16 _reserved; | |
622 | u16 mask_length; | |
623 | sccb_mask_t receive_mask; | |
624 | sccb_mask_t send_mask; | |
1da177e4 | 625 | sccb_mask_t sclp_receive_mask; |
d082d3ce | 626 | sccb_mask_t sclp_send_mask; |
1da177e4 LT |
627 | } __attribute__((packed)); |
628 | ||
629 | /* Prepare init mask request. Called while sclp_lock is locked. */ | |
630 | static inline void | |
631 | __sclp_make_init_req(u32 receive_mask, u32 send_mask) | |
632 | { | |
633 | struct init_sccb *sccb; | |
634 | ||
635 | sccb = (struct init_sccb *) sclp_init_sccb; | |
636 | clear_page(sccb); | |
637 | memset(&sclp_init_req, 0, sizeof(struct sclp_req)); | |
ab14de6c | 638 | sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; |
1da177e4 LT |
639 | sclp_init_req.status = SCLP_REQ_FILLED; |
640 | sclp_init_req.start_count = 0; | |
641 | sclp_init_req.callback = NULL; | |
642 | sclp_init_req.callback_data = NULL; | |
643 | sclp_init_req.sccb = sccb; | |
644 | sccb->header.length = sizeof(struct init_sccb); | |
645 | sccb->mask_length = sizeof(sccb_mask_t); | |
646 | sccb->receive_mask = receive_mask; | |
647 | sccb->send_mask = send_mask; | |
648 | sccb->sclp_receive_mask = 0; | |
649 | sccb->sclp_send_mask = 0; | |
650 | } | |
651 | ||
652 | /* Start init mask request. If calculate is non-zero, calculate the mask as | |
653 | * requested by registered listeners. Use zero mask otherwise. Return 0 on | |
654 | * success, non-zero otherwise. */ | |
655 | static int | |
656 | sclp_init_mask(int calculate) | |
657 | { | |
658 | unsigned long flags; | |
659 | struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; | |
660 | sccb_mask_t receive_mask; | |
661 | sccb_mask_t send_mask; | |
662 | int retry; | |
663 | int rc; | |
664 | unsigned long wait; | |
665 | ||
666 | spin_lock_irqsave(&sclp_lock, flags); | |
667 | /* Check if interface is in appropriate state */ | |
668 | if (sclp_mask_state != sclp_mask_state_idle) { | |
669 | spin_unlock_irqrestore(&sclp_lock, flags); | |
670 | return -EBUSY; | |
671 | } | |
672 | if (sclp_activation_state == sclp_activation_state_inactive) { | |
673 | spin_unlock_irqrestore(&sclp_lock, flags); | |
674 | return -EINVAL; | |
675 | } | |
676 | sclp_mask_state = sclp_mask_state_initializing; | |
677 | /* Determine mask */ | |
678 | if (calculate) | |
679 | __sclp_get_mask(&receive_mask, &send_mask); | |
680 | else { | |
681 | receive_mask = 0; | |
682 | send_mask = 0; | |
683 | } | |
684 | rc = -EIO; | |
685 | for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { | |
686 | /* Prepare request */ | |
687 | __sclp_make_init_req(receive_mask, send_mask); | |
688 | spin_unlock_irqrestore(&sclp_lock, flags); | |
689 | if (sclp_add_request(&sclp_init_req)) { | |
690 | /* Try again later */ | |
691 | wait = jiffies + SCLP_BUSY_INTERVAL * HZ; | |
692 | while (time_before(jiffies, wait)) | |
693 | sclp_sync_wait(); | |
694 | spin_lock_irqsave(&sclp_lock, flags); | |
695 | continue; | |
696 | } | |
697 | while (sclp_init_req.status != SCLP_REQ_DONE && | |
698 | sclp_init_req.status != SCLP_REQ_FAILED) | |
699 | sclp_sync_wait(); | |
700 | spin_lock_irqsave(&sclp_lock, flags); | |
701 | if (sclp_init_req.status == SCLP_REQ_DONE && | |
702 | sccb->header.response_code == 0x20) { | |
703 | /* Successful request */ | |
704 | if (calculate) { | |
705 | sclp_receive_mask = sccb->sclp_receive_mask; | |
706 | sclp_send_mask = sccb->sclp_send_mask; | |
707 | } else { | |
708 | sclp_receive_mask = 0; | |
709 | sclp_send_mask = 0; | |
710 | } | |
711 | spin_unlock_irqrestore(&sclp_lock, flags); | |
712 | sclp_dispatch_state_change(); | |
713 | spin_lock_irqsave(&sclp_lock, flags); | |
714 | rc = 0; | |
715 | break; | |
716 | } | |
717 | } | |
718 | sclp_mask_state = sclp_mask_state_idle; | |
719 | spin_unlock_irqrestore(&sclp_lock, flags); | |
720 | return rc; | |
721 | } | |
722 | ||
723 | /* Deactivate SCLP interface. On success, new requests will be rejected, | |
724 | * events will no longer be dispatched. Return 0 on success, non-zero | |
725 | * otherwise. */ | |
726 | int | |
727 | sclp_deactivate(void) | |
728 | { | |
729 | unsigned long flags; | |
730 | int rc; | |
731 | ||
732 | spin_lock_irqsave(&sclp_lock, flags); | |
733 | /* Deactivate can only be called when active */ | |
734 | if (sclp_activation_state != sclp_activation_state_active) { | |
735 | spin_unlock_irqrestore(&sclp_lock, flags); | |
736 | return -EINVAL; | |
737 | } | |
738 | sclp_activation_state = sclp_activation_state_deactivating; | |
739 | spin_unlock_irqrestore(&sclp_lock, flags); | |
740 | rc = sclp_init_mask(0); | |
741 | spin_lock_irqsave(&sclp_lock, flags); | |
742 | if (rc == 0) | |
743 | sclp_activation_state = sclp_activation_state_inactive; | |
744 | else | |
745 | sclp_activation_state = sclp_activation_state_active; | |
746 | spin_unlock_irqrestore(&sclp_lock, flags); | |
747 | return rc; | |
748 | } | |
749 | ||
750 | EXPORT_SYMBOL(sclp_deactivate); | |
751 | ||
752 | /* Reactivate SCLP interface after sclp_deactivate. On success, new | |
753 | * requests will be accepted, events will be dispatched again. Return 0 on | |
754 | * success, non-zero otherwise. */ | |
755 | int | |
756 | sclp_reactivate(void) | |
757 | { | |
758 | unsigned long flags; | |
759 | int rc; | |
760 | ||
761 | spin_lock_irqsave(&sclp_lock, flags); | |
762 | /* Reactivate can only be called when inactive */ | |
763 | if (sclp_activation_state != sclp_activation_state_inactive) { | |
764 | spin_unlock_irqrestore(&sclp_lock, flags); | |
765 | return -EINVAL; | |
766 | } | |
767 | sclp_activation_state = sclp_activation_state_activating; | |
768 | spin_unlock_irqrestore(&sclp_lock, flags); | |
769 | rc = sclp_init_mask(1); | |
770 | spin_lock_irqsave(&sclp_lock, flags); | |
771 | if (rc == 0) | |
772 | sclp_activation_state = sclp_activation_state_active; | |
773 | else | |
774 | sclp_activation_state = sclp_activation_state_inactive; | |
775 | spin_unlock_irqrestore(&sclp_lock, flags); | |
776 | return rc; | |
777 | } | |
778 | ||
779 | EXPORT_SYMBOL(sclp_reactivate); | |
780 | ||
781 | /* Handler for external interruption used during initialization. Modify | |
782 | * request state to done. */ | |
783 | static void | |
5a489b98 | 784 | sclp_check_handler(__u16 code) |
1da177e4 LT |
785 | { |
786 | u32 finished_sccb; | |
787 | ||
788 | finished_sccb = S390_lowcore.ext_params & 0xfffffff8; | |
789 | /* Is this the interrupt we are waiting for? */ | |
790 | if (finished_sccb == 0) | |
791 | return; | |
a12c53f4 MS |
792 | if (finished_sccb != (u32) (addr_t) sclp_init_sccb) |
793 | panic("sclp: unsolicited interrupt for buffer at 0x%x\n", | |
794 | finished_sccb); | |
1da177e4 LT |
795 | spin_lock(&sclp_lock); |
796 | if (sclp_running_state == sclp_running_state_running) { | |
797 | sclp_init_req.status = SCLP_REQ_DONE; | |
798 | sclp_running_state = sclp_running_state_idle; | |
799 | } | |
800 | spin_unlock(&sclp_lock); | |
801 | } | |
802 | ||
803 | /* Initial init mask request timed out. Modify request state to failed. */ | |
804 | static void | |
805 | sclp_check_timeout(unsigned long data) | |
806 | { | |
807 | unsigned long flags; | |
808 | ||
809 | spin_lock_irqsave(&sclp_lock, flags); | |
810 | if (sclp_running_state == sclp_running_state_running) { | |
811 | sclp_init_req.status = SCLP_REQ_FAILED; | |
812 | sclp_running_state = sclp_running_state_idle; | |
813 | } | |
814 | spin_unlock_irqrestore(&sclp_lock, flags); | |
815 | } | |
816 | ||
817 | /* Perform a check of the SCLP interface. Return zero if the interface is | |
818 | * available and there are no pending requests from a previous instance. | |
819 | * Return non-zero otherwise. */ | |
820 | static int | |
821 | sclp_check_interface(void) | |
822 | { | |
823 | struct init_sccb *sccb; | |
824 | unsigned long flags; | |
825 | int retry; | |
826 | int rc; | |
827 | ||
828 | spin_lock_irqsave(&sclp_lock, flags); | |
829 | /* Prepare init mask command */ | |
830 | rc = register_early_external_interrupt(0x2401, sclp_check_handler, | |
831 | &ext_int_info_hwc); | |
832 | if (rc) { | |
833 | spin_unlock_irqrestore(&sclp_lock, flags); | |
834 | return rc; | |
835 | } | |
836 | for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { | |
837 | __sclp_make_init_req(0, 0); | |
838 | sccb = (struct init_sccb *) sclp_init_req.sccb; | |
ab14de6c | 839 | rc = sclp_service_call(sclp_init_req.command, sccb); |
1da177e4 LT |
840 | if (rc == -EIO) |
841 | break; | |
842 | sclp_init_req.status = SCLP_REQ_RUNNING; | |
843 | sclp_running_state = sclp_running_state_running; | |
844 | __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, | |
845 | sclp_check_timeout, 0); | |
846 | spin_unlock_irqrestore(&sclp_lock, flags); | |
847 | /* Enable service-signal interruption - needs to happen | |
848 | * with IRQs enabled. */ | |
849 | ctl_set_bit(0, 9); | |
850 | /* Wait for signal from interrupt or timeout */ | |
851 | sclp_sync_wait(); | |
852 | /* Disable service-signal interruption - needs to happen | |
853 | * with IRQs enabled. */ | |
854 | ctl_clear_bit(0,9); | |
855 | spin_lock_irqsave(&sclp_lock, flags); | |
856 | del_timer(&sclp_request_timer); | |
857 | if (sclp_init_req.status == SCLP_REQ_DONE && | |
858 | sccb->header.response_code == 0x20) { | |
859 | rc = 0; | |
860 | break; | |
861 | } else | |
862 | rc = -EBUSY; | |
863 | } | |
864 | unregister_early_external_interrupt(0x2401, sclp_check_handler, | |
865 | &ext_int_info_hwc); | |
866 | spin_unlock_irqrestore(&sclp_lock, flags); | |
867 | return rc; | |
868 | } | |
869 | ||
870 | /* Reboot event handler. Reset send and receive mask to prevent pending SCLP | |
871 | * events from interfering with rebooted system. */ | |
872 | static int | |
873 | sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) | |
874 | { | |
875 | sclp_deactivate(); | |
876 | return NOTIFY_DONE; | |
877 | } | |
878 | ||
879 | static struct notifier_block sclp_reboot_notifier = { | |
880 | .notifier_call = sclp_reboot_event | |
881 | }; | |
882 | ||
883 | /* Initialize SCLP driver. Return zero if driver is operational, non-zero | |
884 | * otherwise. */ | |
885 | static int | |
886 | sclp_init(void) | |
887 | { | |
888 | unsigned long flags; | |
889 | int rc; | |
890 | ||
1da177e4 LT |
891 | spin_lock_irqsave(&sclp_lock, flags); |
892 | /* Check for previous or running initialization */ | |
893 | if (sclp_init_state != sclp_init_state_uninitialized) { | |
894 | spin_unlock_irqrestore(&sclp_lock, flags); | |
895 | return 0; | |
896 | } | |
897 | sclp_init_state = sclp_init_state_initializing; | |
898 | /* Set up variables */ | |
899 | INIT_LIST_HEAD(&sclp_req_queue); | |
900 | INIT_LIST_HEAD(&sclp_reg_list); | |
901 | list_add(&sclp_state_change_event.list, &sclp_reg_list); | |
902 | init_timer(&sclp_request_timer); | |
903 | /* Check interface */ | |
904 | spin_unlock_irqrestore(&sclp_lock, flags); | |
905 | rc = sclp_check_interface(); | |
906 | spin_lock_irqsave(&sclp_lock, flags); | |
907 | if (rc) { | |
908 | sclp_init_state = sclp_init_state_uninitialized; | |
909 | spin_unlock_irqrestore(&sclp_lock, flags); | |
910 | return rc; | |
911 | } | |
912 | /* Register reboot handler */ | |
913 | rc = register_reboot_notifier(&sclp_reboot_notifier); | |
914 | if (rc) { | |
915 | sclp_init_state = sclp_init_state_uninitialized; | |
916 | spin_unlock_irqrestore(&sclp_lock, flags); | |
917 | return rc; | |
918 | } | |
919 | /* Register interrupt handler */ | |
920 | rc = register_early_external_interrupt(0x2401, sclp_interrupt_handler, | |
921 | &ext_int_info_hwc); | |
922 | if (rc) { | |
923 | unregister_reboot_notifier(&sclp_reboot_notifier); | |
924 | sclp_init_state = sclp_init_state_uninitialized; | |
925 | spin_unlock_irqrestore(&sclp_lock, flags); | |
926 | return rc; | |
927 | } | |
928 | sclp_init_state = sclp_init_state_initialized; | |
929 | spin_unlock_irqrestore(&sclp_lock, flags); | |
930 | /* Enable service-signal external interruption - needs to happen with | |
931 | * IRQs enabled. */ | |
932 | ctl_set_bit(0, 9); | |
933 | sclp_init_mask(1); | |
934 | return 0; | |
935 | } | |
b3d00c3b PO |
936 | |
937 | static __init int sclp_initcall(void) | |
938 | { | |
939 | return sclp_init(); | |
940 | } | |
941 | ||
942 | arch_initcall(sclp_initcall); |