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eadb86ab SO |
1 | /* |
2 | * Driver for s390 eadm subchannels | |
3 | * | |
4 | * Copyright IBM Corp. 2012 | |
5 | * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com> | |
6 | */ | |
7 | ||
2e73c2cf | 8 | #include <linux/kernel_stat.h> |
6aa2677a | 9 | #include <linux/completion.h> |
eadb86ab SO |
10 | #include <linux/workqueue.h> |
11 | #include <linux/spinlock.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/timer.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/list.h> | |
17 | ||
18 | #include <asm/css_chars.h> | |
19 | #include <asm/debug.h> | |
20 | #include <asm/isc.h> | |
21 | #include <asm/cio.h> | |
22 | #include <asm/scsw.h> | |
23 | #include <asm/eadm.h> | |
24 | ||
25 | #include "eadm_sch.h" | |
26 | #include "ioasm.h" | |
27 | #include "cio.h" | |
28 | #include "css.h" | |
29 | #include "orb.h" | |
30 | ||
31 | MODULE_DESCRIPTION("driver for s390 eadm subchannels"); | |
32 | MODULE_LICENSE("GPL"); | |
33 | ||
34 | #define EADM_TIMEOUT (5 * HZ) | |
35 | static DEFINE_SPINLOCK(list_lock); | |
36 | static LIST_HEAD(eadm_list); | |
37 | ||
38 | static debug_info_t *eadm_debug; | |
39 | ||
40 | #define EADM_LOG(imp, txt) do { \ | |
41 | debug_text_event(eadm_debug, imp, txt); \ | |
42 | } while (0) | |
43 | ||
44 | static void EADM_LOG_HEX(int level, void *data, int length) | |
45 | { | |
8e6a8285 | 46 | if (!debug_level_enabled(eadm_debug, level)) |
eadb86ab SO |
47 | return; |
48 | while (length > 0) { | |
49 | debug_event(eadm_debug, level, data, length); | |
50 | length -= eadm_debug->buf_size; | |
51 | data += eadm_debug->buf_size; | |
52 | } | |
53 | } | |
54 | ||
55 | static void orb_init(union orb *orb) | |
56 | { | |
57 | memset(orb, 0, sizeof(union orb)); | |
58 | orb->eadm.compat1 = 1; | |
59 | orb->eadm.compat2 = 1; | |
60 | orb->eadm.fmt = 1; | |
61 | orb->eadm.x = 1; | |
62 | } | |
63 | ||
64 | static int eadm_subchannel_start(struct subchannel *sch, struct aob *aob) | |
65 | { | |
66 | union orb *orb = &get_eadm_private(sch)->orb; | |
67 | int cc; | |
68 | ||
69 | orb_init(orb); | |
70 | orb->eadm.aob = (u32)__pa(aob); | |
71 | orb->eadm.intparm = (u32)(addr_t)sch; | |
72 | orb->eadm.key = PAGE_DEFAULT_KEY >> 4; | |
73 | ||
74 | EADM_LOG(6, "start"); | |
75 | EADM_LOG_HEX(6, &sch->schid, sizeof(sch->schid)); | |
76 | ||
77 | cc = ssch(sch->schid, orb); | |
78 | switch (cc) { | |
79 | case 0: | |
80 | sch->schib.scsw.eadm.actl |= SCSW_ACTL_START_PEND; | |
81 | break; | |
82 | case 1: /* status pending */ | |
83 | case 2: /* busy */ | |
84 | return -EBUSY; | |
85 | case 3: /* not operational */ | |
86 | return -ENODEV; | |
87 | } | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static int eadm_subchannel_clear(struct subchannel *sch) | |
92 | { | |
93 | int cc; | |
94 | ||
95 | cc = csch(sch->schid); | |
96 | if (cc) | |
97 | return -ENODEV; | |
98 | ||
99 | sch->schib.scsw.eadm.actl |= SCSW_ACTL_CLEAR_PEND; | |
100 | return 0; | |
101 | } | |
102 | ||
103 | static void eadm_subchannel_timeout(unsigned long data) | |
104 | { | |
105 | struct subchannel *sch = (struct subchannel *) data; | |
106 | ||
107 | spin_lock_irq(sch->lock); | |
108 | EADM_LOG(1, "timeout"); | |
109 | EADM_LOG_HEX(1, &sch->schid, sizeof(sch->schid)); | |
110 | if (eadm_subchannel_clear(sch)) | |
111 | EADM_LOG(0, "clear failed"); | |
112 | spin_unlock_irq(sch->lock); | |
113 | } | |
114 | ||
115 | static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires) | |
116 | { | |
117 | struct eadm_private *private = get_eadm_private(sch); | |
118 | ||
119 | if (expires == 0) { | |
120 | del_timer(&private->timer); | |
121 | return; | |
122 | } | |
123 | if (timer_pending(&private->timer)) { | |
124 | if (mod_timer(&private->timer, jiffies + expires)) | |
125 | return; | |
126 | } | |
127 | private->timer.function = eadm_subchannel_timeout; | |
128 | private->timer.data = (unsigned long) sch; | |
129 | private->timer.expires = jiffies + expires; | |
130 | add_timer(&private->timer); | |
131 | } | |
132 | ||
133 | static void eadm_subchannel_irq(struct subchannel *sch) | |
134 | { | |
135 | struct eadm_private *private = get_eadm_private(sch); | |
136 | struct eadm_scsw *scsw = &sch->schib.scsw.eadm; | |
137 | struct irb *irb = (struct irb *)&S390_lowcore.irb; | |
138 | int error = 0; | |
139 | ||
140 | EADM_LOG(6, "irq"); | |
141 | EADM_LOG_HEX(6, irb, sizeof(*irb)); | |
142 | ||
420f42ec | 143 | inc_irq_stat(IRQIO_ADM); |
2e73c2cf | 144 | |
eadb86ab SO |
145 | if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) |
146 | && scsw->eswf == 1 && irb->esw.eadm.erw.r) | |
147 | error = -EIO; | |
148 | ||
149 | if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC) | |
150 | error = -ETIMEDOUT; | |
151 | ||
152 | eadm_subchannel_set_timeout(sch, 0); | |
153 | ||
154 | if (private->state != EADM_BUSY) { | |
155 | EADM_LOG(1, "irq unsol"); | |
156 | EADM_LOG_HEX(1, irb, sizeof(*irb)); | |
157 | private->state = EADM_NOT_OPER; | |
158 | css_sched_sch_todo(sch, SCH_TODO_EVAL); | |
159 | return; | |
160 | } | |
161 | scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error); | |
162 | private->state = EADM_IDLE; | |
6aa2677a SO |
163 | |
164 | if (private->completion) | |
165 | complete(private->completion); | |
eadb86ab SO |
166 | } |
167 | ||
168 | static struct subchannel *eadm_get_idle_sch(void) | |
169 | { | |
170 | struct eadm_private *private; | |
171 | struct subchannel *sch; | |
172 | unsigned long flags; | |
173 | ||
174 | spin_lock_irqsave(&list_lock, flags); | |
175 | list_for_each_entry(private, &eadm_list, head) { | |
176 | sch = private->sch; | |
177 | spin_lock(sch->lock); | |
178 | if (private->state == EADM_IDLE) { | |
179 | private->state = EADM_BUSY; | |
180 | list_move_tail(&private->head, &eadm_list); | |
181 | spin_unlock(sch->lock); | |
182 | spin_unlock_irqrestore(&list_lock, flags); | |
183 | ||
184 | return sch; | |
185 | } | |
186 | spin_unlock(sch->lock); | |
187 | } | |
188 | spin_unlock_irqrestore(&list_lock, flags); | |
189 | ||
190 | return NULL; | |
191 | } | |
192 | ||
193 | static int eadm_start_aob(struct aob *aob) | |
194 | { | |
195 | struct eadm_private *private; | |
196 | struct subchannel *sch; | |
197 | unsigned long flags; | |
198 | int ret; | |
199 | ||
200 | sch = eadm_get_idle_sch(); | |
201 | if (!sch) | |
202 | return -EBUSY; | |
203 | ||
204 | spin_lock_irqsave(sch->lock, flags); | |
205 | eadm_subchannel_set_timeout(sch, EADM_TIMEOUT); | |
206 | ret = eadm_subchannel_start(sch, aob); | |
207 | if (!ret) | |
208 | goto out_unlock; | |
209 | ||
210 | /* Handle start subchannel failure. */ | |
211 | eadm_subchannel_set_timeout(sch, 0); | |
212 | private = get_eadm_private(sch); | |
213 | private->state = EADM_NOT_OPER; | |
214 | css_sched_sch_todo(sch, SCH_TODO_EVAL); | |
215 | ||
216 | out_unlock: | |
217 | spin_unlock_irqrestore(sch->lock, flags); | |
218 | ||
219 | return ret; | |
220 | } | |
221 | ||
222 | static int eadm_subchannel_probe(struct subchannel *sch) | |
223 | { | |
224 | struct eadm_private *private; | |
225 | int ret; | |
226 | ||
227 | private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); | |
228 | if (!private) | |
229 | return -ENOMEM; | |
230 | ||
231 | INIT_LIST_HEAD(&private->head); | |
232 | init_timer(&private->timer); | |
233 | ||
234 | spin_lock_irq(sch->lock); | |
235 | set_eadm_private(sch, private); | |
236 | private->state = EADM_IDLE; | |
237 | private->sch = sch; | |
238 | sch->isc = EADM_SCH_ISC; | |
239 | ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); | |
240 | if (ret) { | |
241 | set_eadm_private(sch, NULL); | |
242 | spin_unlock_irq(sch->lock); | |
243 | kfree(private); | |
244 | goto out; | |
245 | } | |
246 | spin_unlock_irq(sch->lock); | |
247 | ||
248 | spin_lock_irq(&list_lock); | |
249 | list_add(&private->head, &eadm_list); | |
250 | spin_unlock_irq(&list_lock); | |
251 | ||
252 | if (dev_get_uevent_suppress(&sch->dev)) { | |
253 | dev_set_uevent_suppress(&sch->dev, 0); | |
254 | kobject_uevent(&sch->dev.kobj, KOBJ_ADD); | |
255 | } | |
256 | out: | |
257 | return ret; | |
258 | } | |
259 | ||
260 | static void eadm_quiesce(struct subchannel *sch) | |
261 | { | |
6aa2677a SO |
262 | struct eadm_private *private = get_eadm_private(sch); |
263 | DECLARE_COMPLETION_ONSTACK(completion); | |
eadb86ab SO |
264 | int ret; |
265 | ||
6aa2677a SO |
266 | spin_lock_irq(sch->lock); |
267 | if (private->state != EADM_BUSY) | |
268 | goto disable; | |
269 | ||
270 | if (eadm_subchannel_clear(sch)) | |
271 | goto disable; | |
272 | ||
273 | private->completion = &completion; | |
274 | spin_unlock_irq(sch->lock); | |
275 | ||
276 | wait_for_completion_io(&completion); | |
277 | ||
278 | spin_lock_irq(sch->lock); | |
279 | private->completion = NULL; | |
280 | ||
281 | disable: | |
282 | eadm_subchannel_set_timeout(sch, 0); | |
eadb86ab | 283 | do { |
eadb86ab | 284 | ret = cio_disable_subchannel(sch); |
eadb86ab | 285 | } while (ret == -EBUSY); |
6aa2677a SO |
286 | |
287 | spin_unlock_irq(sch->lock); | |
eadb86ab SO |
288 | } |
289 | ||
290 | static int eadm_subchannel_remove(struct subchannel *sch) | |
291 | { | |
292 | struct eadm_private *private = get_eadm_private(sch); | |
293 | ||
294 | spin_lock_irq(&list_lock); | |
295 | list_del(&private->head); | |
296 | spin_unlock_irq(&list_lock); | |
297 | ||
298 | eadm_quiesce(sch); | |
299 | ||
300 | spin_lock_irq(sch->lock); | |
301 | set_eadm_private(sch, NULL); | |
302 | spin_unlock_irq(sch->lock); | |
303 | ||
304 | kfree(private); | |
305 | ||
306 | return 0; | |
307 | } | |
308 | ||
309 | static void eadm_subchannel_shutdown(struct subchannel *sch) | |
310 | { | |
311 | eadm_quiesce(sch); | |
312 | } | |
313 | ||
314 | static int eadm_subchannel_freeze(struct subchannel *sch) | |
315 | { | |
316 | return cio_disable_subchannel(sch); | |
317 | } | |
318 | ||
319 | static int eadm_subchannel_restore(struct subchannel *sch) | |
320 | { | |
321 | return cio_enable_subchannel(sch, (u32)(unsigned long)sch); | |
322 | } | |
323 | ||
324 | /** | |
325 | * eadm_subchannel_sch_event - process subchannel event | |
326 | * @sch: subchannel | |
327 | * @process: non-zero if function is called in process context | |
328 | * | |
329 | * An unspecified event occurred for this subchannel. Adjust data according | |
330 | * to the current operational state of the subchannel. Return zero when the | |
331 | * event has been handled sufficiently or -EAGAIN when this function should | |
332 | * be called again in process context. | |
333 | */ | |
334 | static int eadm_subchannel_sch_event(struct subchannel *sch, int process) | |
335 | { | |
336 | struct eadm_private *private; | |
337 | unsigned long flags; | |
338 | int ret = 0; | |
339 | ||
340 | spin_lock_irqsave(sch->lock, flags); | |
341 | if (!device_is_registered(&sch->dev)) | |
342 | goto out_unlock; | |
343 | ||
344 | if (work_pending(&sch->todo_work)) | |
345 | goto out_unlock; | |
346 | ||
347 | if (cio_update_schib(sch)) { | |
348 | css_sched_sch_todo(sch, SCH_TODO_UNREG); | |
349 | goto out_unlock; | |
350 | } | |
351 | private = get_eadm_private(sch); | |
352 | if (private->state == EADM_NOT_OPER) | |
353 | private->state = EADM_IDLE; | |
354 | ||
355 | out_unlock: | |
356 | spin_unlock_irqrestore(sch->lock, flags); | |
357 | ||
358 | return ret; | |
359 | } | |
360 | ||
361 | static struct css_device_id eadm_subchannel_ids[] = { | |
362 | { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, }, | |
363 | { /* end of list */ }, | |
364 | }; | |
365 | MODULE_DEVICE_TABLE(css, eadm_subchannel_ids); | |
366 | ||
367 | static struct css_driver eadm_subchannel_driver = { | |
368 | .drv = { | |
369 | .name = "eadm_subchannel", | |
370 | .owner = THIS_MODULE, | |
371 | }, | |
372 | .subchannel_type = eadm_subchannel_ids, | |
373 | .irq = eadm_subchannel_irq, | |
374 | .probe = eadm_subchannel_probe, | |
375 | .remove = eadm_subchannel_remove, | |
376 | .shutdown = eadm_subchannel_shutdown, | |
377 | .sch_event = eadm_subchannel_sch_event, | |
378 | .freeze = eadm_subchannel_freeze, | |
379 | .thaw = eadm_subchannel_restore, | |
380 | .restore = eadm_subchannel_restore, | |
381 | }; | |
382 | ||
383 | static struct eadm_ops eadm_ops = { | |
384 | .eadm_start = eadm_start_aob, | |
385 | .owner = THIS_MODULE, | |
386 | }; | |
387 | ||
388 | static int __init eadm_sch_init(void) | |
389 | { | |
390 | int ret; | |
391 | ||
392 | if (!css_general_characteristics.eadm) | |
393 | return -ENXIO; | |
394 | ||
395 | eadm_debug = debug_register("eadm_log", 16, 1, 16); | |
396 | if (!eadm_debug) | |
397 | return -ENOMEM; | |
398 | ||
399 | debug_register_view(eadm_debug, &debug_hex_ascii_view); | |
400 | debug_set_level(eadm_debug, 2); | |
401 | ||
402 | isc_register(EADM_SCH_ISC); | |
403 | ret = css_driver_register(&eadm_subchannel_driver); | |
404 | if (ret) | |
405 | goto cleanup; | |
406 | ||
407 | register_eadm_ops(&eadm_ops); | |
408 | return ret; | |
409 | ||
410 | cleanup: | |
411 | isc_unregister(EADM_SCH_ISC); | |
412 | debug_unregister(eadm_debug); | |
413 | return ret; | |
414 | } | |
415 | ||
416 | static void __exit eadm_sch_exit(void) | |
417 | { | |
418 | unregister_eadm_ops(&eadm_ops); | |
419 | css_driver_unregister(&eadm_subchannel_driver); | |
420 | isc_unregister(EADM_SCH_ISC); | |
421 | debug_unregister(eadm_debug); | |
422 | } | |
423 | module_init(eadm_sch_init); | |
424 | module_exit(eadm_sch_exit); |