Commit | Line | Data |
---|---|---|
55bd2133 JR |
1 | /* vcc.c: sun4v virtual channel concentrator |
2 | * | |
3 | * Copyright (C) 2017 Oracle. All rights reserved. | |
4 | */ | |
5 | ||
5d171050 JR |
6 | #include <linux/delay.h> |
7 | #include <linux/interrupt.h> | |
55bd2133 | 8 | #include <linux/module.h> |
5d171050 | 9 | #include <linux/slab.h> |
8868e44a | 10 | #include <linux/sysfs.h> |
ce808b74 | 11 | #include <linux/tty.h> |
f8c55335 | 12 | #include <linux/tty_flip.h> |
5d171050 JR |
13 | #include <asm/vio.h> |
14 | #include <asm/ldc.h> | |
55bd2133 | 15 | |
f283ebd5 JR |
16 | #define DRV_MODULE_NAME "vcc" |
17 | #define DRV_MODULE_VERSION "1.1" | |
18 | #define DRV_MODULE_RELDATE "July 1, 2017" | |
19 | ||
ce808b74 JR |
20 | static char version[] = |
21 | DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")"; | |
22 | ||
f283ebd5 JR |
23 | MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver"); |
24 | MODULE_LICENSE("GPL"); | |
25 | MODULE_VERSION(DRV_MODULE_VERSION); | |
26 | ||
5d171050 JR |
27 | struct vcc_port { |
28 | struct vio_driver_state vio; | |
29 | ||
30 | spinlock_t lock; | |
31 | char *domain; | |
32 | struct tty_struct *tty; /* only populated while dev is open */ | |
33 | unsigned long index; /* index into the vcc_table */ | |
34 | ||
35 | u64 refcnt; | |
36 | bool excl_locked; | |
37 | ||
38 | bool removed; | |
39 | ||
40 | /* This buffer is required to support the tty write_room interface | |
41 | * and guarantee that any characters that the driver accepts will | |
42 | * be eventually sent, either immediately or later. | |
43 | */ | |
44 | int chars_in_buffer; | |
45 | struct vio_vcc buffer; | |
46 | ||
47 | struct timer_list rx_timer; | |
48 | struct timer_list tx_timer; | |
49 | }; | |
50 | ||
51 | /* Microseconds that thread will delay waiting for a vcc port ref */ | |
52 | #define VCC_REF_DELAY 100 | |
53 | ||
ce808b74 JR |
54 | #define VCC_MAX_PORTS 1024 |
55 | #define VCC_MINOR_START 0 /* must be zero */ | |
f8c55335 | 56 | #define VCC_BUFF_LEN VIO_VCC_MTU_SIZE |
ce808b74 | 57 | |
8868e44a JR |
58 | #define VCC_CTL_BREAK -1 |
59 | #define VCC_CTL_HUP -2 | |
60 | ||
ce808b74 JR |
61 | static const char vcc_driver_name[] = "vcc"; |
62 | static const char vcc_device_node[] = "vcc"; | |
63 | static struct tty_driver *vcc_tty_driver; | |
64 | ||
5d171050 JR |
65 | static struct vcc_port *vcc_table[VCC_MAX_PORTS]; |
66 | static DEFINE_SPINLOCK(vcc_table_lock); | |
67 | ||
f283ebd5 JR |
68 | int vcc_dbg; |
69 | int vcc_dbg_ldc; | |
70 | int vcc_dbg_vio; | |
71 | ||
72 | module_param(vcc_dbg, uint, 0664); | |
73 | module_param(vcc_dbg_ldc, uint, 0664); | |
74 | module_param(vcc_dbg_vio, uint, 0664); | |
75 | ||
76 | #define VCC_DBG_DRV 0x1 | |
77 | #define VCC_DBG_LDC 0x2 | |
78 | #define VCC_DBG_PKT 0x4 | |
79 | ||
80 | #define vccdbg(f, a...) \ | |
81 | do { \ | |
82 | if (vcc_dbg & VCC_DBG_DRV) \ | |
83 | pr_info(f, ## a); \ | |
84 | } while (0) \ | |
85 | ||
86 | #define vccdbgl(l) \ | |
87 | do { \ | |
88 | if (vcc_dbg & VCC_DBG_LDC) \ | |
89 | ldc_print(l); \ | |
90 | } while (0) \ | |
91 | ||
92 | #define vccdbgp(pkt) \ | |
93 | do { \ | |
94 | if (vcc_dbg & VCC_DBG_PKT) { \ | |
95 | int i; \ | |
96 | for (i = 0; i < pkt.tag.stype; i++) \ | |
97 | pr_info("[%c]", pkt.data[i]); \ | |
98 | } \ | |
99 | } while (0) \ | |
100 | ||
ce808b74 JR |
101 | /* Note: Be careful when adding flags to this line discipline. Don't |
102 | * add anything that will cause echoing or we'll go into recursive | |
103 | * loop echoing chars back and forth with the console drivers. | |
104 | */ | |
105 | static struct ktermios vcc_tty_termios = { | |
106 | .c_iflag = IGNBRK | IGNPAR, | |
107 | .c_oflag = OPOST, | |
108 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
109 | .c_cc = INIT_C_CC, | |
110 | .c_ispeed = 38400, | |
111 | .c_ospeed = 38400 | |
112 | }; | |
113 | ||
5d171050 JR |
114 | /** |
115 | * vcc_table_add() - Add VCC port to the VCC table | |
116 | * @port: pointer to the VCC port | |
117 | * | |
118 | * Return: index of the port in the VCC table on success, | |
119 | * -1 on failure | |
120 | */ | |
121 | static int vcc_table_add(struct vcc_port *port) | |
122 | { | |
123 | unsigned long flags; | |
124 | int i; | |
125 | ||
126 | spin_lock_irqsave(&vcc_table_lock, flags); | |
127 | for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) { | |
128 | if (!vcc_table[i]) { | |
129 | vcc_table[i] = port; | |
130 | break; | |
131 | } | |
132 | } | |
133 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
134 | ||
135 | if (i < VCC_MAX_PORTS) | |
136 | return i; | |
137 | else | |
138 | return -1; | |
139 | } | |
140 | ||
141 | /** | |
142 | * vcc_table_remove() - Removes a VCC port from the VCC table | |
143 | * @index: Index into the VCC table | |
144 | */ | |
145 | static void vcc_table_remove(unsigned long index) | |
146 | { | |
147 | unsigned long flags; | |
148 | ||
149 | if (WARN_ON(index >= VCC_MAX_PORTS)) | |
150 | return; | |
151 | ||
152 | spin_lock_irqsave(&vcc_table_lock, flags); | |
153 | vcc_table[index] = NULL; | |
154 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
155 | } | |
156 | ||
157 | /** | |
158 | * vcc_get() - Gets a reference to VCC port | |
159 | * @index: Index into the VCC table | |
160 | * @excl: Indicates if an exclusive access is requested | |
161 | * | |
162 | * Return: reference to the VCC port, if found | |
163 | * NULL, if port not found | |
164 | */ | |
165 | static struct vcc_port *vcc_get(unsigned long index, bool excl) | |
166 | { | |
167 | struct vcc_port *port; | |
168 | unsigned long flags; | |
169 | ||
170 | try_again: | |
171 | spin_lock_irqsave(&vcc_table_lock, flags); | |
172 | ||
173 | port = vcc_table[index]; | |
174 | if (!port) { | |
175 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
176 | return NULL; | |
177 | } | |
178 | ||
179 | if (!excl) { | |
180 | if (port->excl_locked) { | |
181 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
182 | udelay(VCC_REF_DELAY); | |
183 | goto try_again; | |
184 | } | |
185 | port->refcnt++; | |
186 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
187 | return port; | |
188 | } | |
189 | ||
190 | if (port->refcnt) { | |
191 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
192 | /* Threads wanting exclusive access will wait half the time, | |
193 | * probably giving them higher priority in the case of | |
194 | * multiple waiters. | |
195 | */ | |
196 | udelay(VCC_REF_DELAY/2); | |
197 | goto try_again; | |
198 | } | |
199 | ||
200 | port->refcnt++; | |
201 | port->excl_locked = true; | |
202 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
203 | ||
204 | return port; | |
205 | } | |
206 | ||
207 | /** | |
208 | * vcc_put() - Returns a reference to VCC port | |
209 | * @port: pointer to VCC port | |
210 | * @excl: Indicates if the returned reference is an exclusive reference | |
211 | * | |
212 | * Note: It's the caller's responsibility to ensure the correct value | |
213 | * for the excl flag | |
214 | */ | |
215 | static void vcc_put(struct vcc_port *port, bool excl) | |
216 | { | |
217 | unsigned long flags; | |
218 | ||
219 | if (!port) | |
220 | return; | |
221 | ||
222 | spin_lock_irqsave(&vcc_table_lock, flags); | |
223 | ||
224 | /* check if caller attempted to put with the wrong flags */ | |
225 | if (WARN_ON((excl && !port->excl_locked) || | |
226 | (!excl && port->excl_locked))) | |
227 | goto done; | |
228 | ||
229 | port->refcnt--; | |
230 | ||
231 | if (excl) | |
232 | port->excl_locked = false; | |
233 | ||
234 | done: | |
235 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
236 | } | |
237 | ||
238 | /** | |
239 | * vcc_get_ne() - Get a non-exclusive reference to VCC port | |
240 | * @index: Index into the VCC table | |
241 | * | |
242 | * Gets a non-exclusive reference to VCC port, if it's not removed | |
243 | * | |
244 | * Return: pointer to the VCC port, if found | |
245 | * NULL, if port not found | |
246 | */ | |
247 | static struct vcc_port *vcc_get_ne(unsigned long index) | |
248 | { | |
249 | struct vcc_port *port; | |
250 | ||
251 | port = vcc_get(index, false); | |
252 | ||
253 | if (port && port->removed) { | |
254 | vcc_put(port, false); | |
255 | return NULL; | |
256 | } | |
257 | ||
258 | return port; | |
259 | } | |
260 | ||
f8c55335 JR |
261 | static void vcc_kick_rx(struct vcc_port *port) |
262 | { | |
263 | struct vio_driver_state *vio = &port->vio; | |
264 | ||
265 | assert_spin_locked(&port->lock); | |
266 | ||
267 | if (!timer_pending(&port->rx_timer) && !port->removed) { | |
268 | disable_irq_nosync(vio->vdev->rx_irq); | |
269 | port->rx_timer.expires = (jiffies + 1); | |
270 | add_timer(&port->rx_timer); | |
271 | } | |
272 | } | |
273 | ||
274 | static void vcc_kick_tx(struct vcc_port *port) | |
275 | { | |
276 | assert_spin_locked(&port->lock); | |
277 | ||
278 | if (!timer_pending(&port->tx_timer) && !port->removed) { | |
279 | port->tx_timer.expires = (jiffies + 1); | |
280 | add_timer(&port->tx_timer); | |
281 | } | |
282 | } | |
283 | ||
284 | static int vcc_rx_check(struct tty_struct *tty, int size) | |
285 | { | |
286 | if (WARN_ON(!tty || !tty->port)) | |
287 | return 1; | |
288 | ||
289 | /* tty_buffer_request_room won't sleep because it uses | |
290 | * GFP_ATOMIC flag to allocate buffer | |
291 | */ | |
292 | if (test_bit(TTY_THROTTLED, &tty->flags) || | |
293 | (tty_buffer_request_room(tty->port, VCC_BUFF_LEN) < VCC_BUFF_LEN)) | |
294 | return 0; | |
295 | ||
296 | return 1; | |
297 | } | |
298 | ||
299 | static int vcc_rx(struct tty_struct *tty, char *buf, int size) | |
300 | { | |
301 | int len = 0; | |
302 | ||
303 | if (WARN_ON(!tty || !tty->port)) | |
304 | return len; | |
305 | ||
306 | len = tty_insert_flip_string(tty->port, buf, size); | |
307 | if (len) | |
308 | tty_flip_buffer_push(tty->port); | |
309 | ||
310 | return len; | |
311 | } | |
312 | ||
313 | static int vcc_ldc_read(struct vcc_port *port) | |
314 | { | |
315 | struct vio_driver_state *vio = &port->vio; | |
316 | struct tty_struct *tty; | |
317 | struct vio_vcc pkt; | |
318 | int rv = 0; | |
319 | ||
320 | tty = port->tty; | |
321 | if (!tty) { | |
322 | rv = ldc_rx_reset(vio->lp); | |
323 | vccdbg("VCC: reset rx q: rv=%d\n", rv); | |
324 | goto done; | |
325 | } | |
326 | ||
327 | /* Read as long as LDC has incoming data. */ | |
328 | while (1) { | |
329 | if (!vcc_rx_check(tty, VIO_VCC_MTU_SIZE)) { | |
330 | vcc_kick_rx(port); | |
331 | break; | |
332 | } | |
333 | ||
334 | vccdbgl(vio->lp); | |
335 | ||
336 | rv = ldc_read(vio->lp, &pkt, sizeof(pkt)); | |
337 | if (rv <= 0) | |
338 | break; | |
339 | ||
340 | vccdbg("VCC: ldc_read()=%d\n", rv); | |
341 | vccdbg("TAG [%02x:%02x:%04x:%08x]\n", | |
342 | pkt.tag.type, pkt.tag.stype, | |
343 | pkt.tag.stype_env, pkt.tag.sid); | |
344 | ||
345 | if (pkt.tag.type == VIO_TYPE_DATA) { | |
346 | vccdbgp(pkt); | |
347 | /* vcc_rx_check ensures memory availability */ | |
348 | vcc_rx(tty, pkt.data, pkt.tag.stype); | |
349 | } else { | |
350 | pr_err("VCC: unknown msg [%02x:%02x:%04x:%08x]\n", | |
351 | pkt.tag.type, pkt.tag.stype, | |
352 | pkt.tag.stype_env, pkt.tag.sid); | |
353 | rv = -ECONNRESET; | |
354 | break; | |
355 | } | |
356 | ||
357 | WARN_ON(rv != LDC_PACKET_SIZE); | |
358 | } | |
359 | ||
360 | done: | |
361 | return rv; | |
362 | } | |
363 | ||
364 | static void vcc_rx_timer(unsigned long index) | |
365 | { | |
366 | struct vio_driver_state *vio; | |
367 | struct vcc_port *port; | |
368 | unsigned long flags; | |
369 | int rv; | |
370 | ||
371 | port = vcc_get_ne(index); | |
372 | if (!port) | |
373 | return; | |
374 | ||
375 | spin_lock_irqsave(&port->lock, flags); | |
376 | port->rx_timer.expires = 0; | |
377 | ||
378 | vio = &port->vio; | |
379 | ||
380 | enable_irq(vio->vdev->rx_irq); | |
381 | ||
382 | if (!port->tty || port->removed) | |
383 | goto done; | |
384 | ||
385 | rv = vcc_ldc_read(port); | |
386 | if (rv == -ECONNRESET) | |
387 | vio_conn_reset(vio); | |
388 | ||
389 | done: | |
390 | spin_unlock_irqrestore(&port->lock, flags); | |
391 | vcc_put(port, false); | |
392 | } | |
393 | ||
394 | static void vcc_tx_timer(unsigned long index) | |
395 | { | |
396 | struct vcc_port *port; | |
397 | struct vio_vcc *pkt; | |
398 | unsigned long flags; | |
399 | int tosend = 0; | |
400 | int rv; | |
401 | ||
402 | port = vcc_get_ne(index); | |
403 | if (!port) | |
404 | return; | |
405 | ||
406 | spin_lock_irqsave(&port->lock, flags); | |
407 | port->tx_timer.expires = 0; | |
408 | ||
409 | if (!port->tty || port->removed) | |
410 | goto done; | |
411 | ||
412 | tosend = min(VCC_BUFF_LEN, port->chars_in_buffer); | |
413 | if (!tosend) | |
414 | goto done; | |
415 | ||
416 | pkt = &port->buffer; | |
417 | pkt->tag.type = VIO_TYPE_DATA; | |
418 | pkt->tag.stype = tosend; | |
419 | vccdbgl(port->vio.lp); | |
420 | ||
421 | rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend)); | |
422 | WARN_ON(!rv); | |
423 | ||
424 | if (rv < 0) { | |
425 | vccdbg("VCC: ldc_write()=%d\n", rv); | |
426 | vcc_kick_tx(port); | |
427 | } else { | |
428 | struct tty_struct *tty = port->tty; | |
429 | ||
430 | port->chars_in_buffer = 0; | |
431 | if (tty) | |
432 | tty_wakeup(tty); | |
433 | } | |
434 | ||
435 | done: | |
436 | spin_unlock_irqrestore(&port->lock, flags); | |
437 | vcc_put(port, false); | |
438 | } | |
439 | ||
103b9b0b JR |
440 | /** |
441 | * vcc_event() - LDC event processing engine | |
442 | * @arg: VCC private data | |
443 | * @event: LDC event | |
444 | * | |
445 | * Handles LDC events for VCC | |
446 | */ | |
5d171050 JR |
447 | static void vcc_event(void *arg, int event) |
448 | { | |
103b9b0b JR |
449 | struct vio_driver_state *vio; |
450 | struct vcc_port *port; | |
451 | unsigned long flags; | |
452 | int rv; | |
453 | ||
454 | port = arg; | |
455 | vio = &port->vio; | |
456 | ||
457 | spin_lock_irqsave(&port->lock, flags); | |
458 | ||
459 | switch (event) { | |
460 | case LDC_EVENT_RESET: | |
461 | case LDC_EVENT_UP: | |
462 | vio_link_state_change(vio, event); | |
463 | break; | |
464 | ||
465 | case LDC_EVENT_DATA_READY: | |
466 | rv = vcc_ldc_read(port); | |
467 | if (rv == -ECONNRESET) | |
468 | vio_conn_reset(vio); | |
469 | break; | |
470 | ||
471 | default: | |
472 | pr_err("VCC: unexpected LDC event(%d)\n", event); | |
473 | } | |
474 | ||
475 | spin_unlock_irqrestore(&port->lock, flags); | |
5d171050 JR |
476 | } |
477 | ||
478 | static struct ldc_channel_config vcc_ldc_cfg = { | |
479 | .event = vcc_event, | |
480 | .mtu = VIO_VCC_MTU_SIZE, | |
481 | .mode = LDC_MODE_RAW, | |
482 | .debug = 0, | |
483 | }; | |
484 | ||
485 | /* Ordered from largest major to lowest */ | |
486 | static struct vio_version vcc_versions[] = { | |
487 | { .major = 1, .minor = 0 }, | |
488 | }; | |
489 | ||
8868e44a JR |
490 | static ssize_t vcc_sysfs_domain_show(struct device *dev, |
491 | struct device_attribute *attr, | |
492 | char *buf) | |
493 | { | |
494 | struct vcc_port *port; | |
495 | int rv; | |
496 | ||
497 | port = dev_get_drvdata(dev); | |
498 | if (!port) | |
499 | return -ENODEV; | |
500 | ||
501 | rv = scnprintf(buf, PAGE_SIZE, "%s\n", port->domain); | |
502 | ||
503 | return rv; | |
504 | } | |
505 | ||
506 | static int vcc_send_ctl(struct vcc_port *port, int ctl) | |
507 | { | |
508 | struct vio_vcc pkt; | |
509 | int rv; | |
510 | ||
511 | pkt.tag.type = VIO_TYPE_CTRL; | |
512 | pkt.tag.sid = ctl; | |
513 | pkt.tag.stype = 0; | |
514 | ||
515 | rv = ldc_write(port->vio.lp, &pkt, sizeof(pkt.tag)); | |
516 | WARN_ON(!rv); | |
517 | vccdbg("VCC: ldc_write(%ld)=%d\n", sizeof(pkt.tag), rv); | |
518 | ||
519 | return rv; | |
520 | } | |
521 | ||
522 | static ssize_t vcc_sysfs_break_store(struct device *dev, | |
523 | struct device_attribute *attr, | |
524 | const char *buf, size_t count) | |
525 | { | |
526 | struct vcc_port *port; | |
527 | unsigned long flags; | |
528 | int rv = count; | |
529 | int brk; | |
530 | ||
531 | port = dev_get_drvdata(dev); | |
532 | if (!port) | |
533 | return -ENODEV; | |
534 | ||
535 | spin_lock_irqsave(&port->lock, flags); | |
536 | ||
537 | if (sscanf(buf, "%ud", &brk) != 1 || brk != 1) | |
538 | rv = -EINVAL; | |
539 | else if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0) | |
f8c55335 | 540 | vcc_kick_tx(port); |
8868e44a JR |
541 | |
542 | spin_unlock_irqrestore(&port->lock, flags); | |
543 | ||
544 | return rv; | |
545 | } | |
546 | ||
547 | static DEVICE_ATTR(domain, 0400, vcc_sysfs_domain_show, NULL); | |
548 | static DEVICE_ATTR(break, 0200, NULL, vcc_sysfs_break_store); | |
549 | ||
550 | static struct attribute *vcc_sysfs_entries[] = { | |
551 | &dev_attr_domain.attr, | |
552 | &dev_attr_break.attr, | |
553 | NULL | |
554 | }; | |
555 | ||
556 | static struct attribute_group vcc_attribute_group = { | |
557 | .name = NULL, | |
558 | .attrs = vcc_sysfs_entries, | |
559 | }; | |
560 | ||
5d171050 JR |
561 | /** |
562 | * vcc_probe() - Initialize VCC port | |
563 | * @vdev: Pointer to VIO device of the new VCC port | |
564 | * @id: VIO device ID | |
565 | * | |
566 | * Initializes a VCC port to receive serial console data from | |
567 | * the guest domain. Sets up a TTY end point on the control | |
568 | * domain. Sets up VIO/LDC link between the guest & control | |
569 | * domain endpoints. | |
570 | * | |
571 | * Return: status of the probe | |
572 | */ | |
573 | static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id) | |
574 | { | |
575 | struct mdesc_handle *hp; | |
576 | struct vcc_port *port; | |
577 | struct device *dev; | |
578 | const char *domain; | |
579 | char *name; | |
580 | u64 node; | |
581 | int rv; | |
582 | ||
583 | vccdbg("VCC: name=%s\n", dev_name(&vdev->dev)); | |
584 | ||
585 | if (!vcc_tty_driver) { | |
586 | pr_err("VCC: TTY driver not registered\n"); | |
587 | return -ENODEV; | |
588 | } | |
589 | ||
590 | port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL); | |
591 | if (!port) | |
592 | return -ENOMEM; | |
593 | ||
594 | name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL); | |
595 | ||
596 | rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions, | |
597 | ARRAY_SIZE(vcc_versions), NULL, name); | |
598 | if (rv) | |
599 | goto free_port; | |
600 | ||
601 | port->vio.debug = vcc_dbg_vio; | |
602 | vcc_ldc_cfg.debug = vcc_dbg_ldc; | |
603 | ||
604 | rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port); | |
605 | if (rv) | |
606 | goto free_port; | |
607 | ||
608 | spin_lock_init(&port->lock); | |
609 | ||
610 | port->index = vcc_table_add(port); | |
611 | if (port->index == -1) { | |
612 | pr_err("VCC: no more TTY indices left for allocation\n"); | |
613 | goto free_ldc; | |
614 | } | |
615 | ||
616 | /* Register the device using VCC table index as TTY index */ | |
617 | dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev); | |
618 | if (IS_ERR(dev)) { | |
619 | rv = PTR_ERR(dev); | |
620 | goto free_table; | |
621 | } | |
622 | ||
623 | hp = mdesc_grab(); | |
624 | ||
625 | node = vio_vdev_node(hp, vdev); | |
626 | if (node == MDESC_NODE_NULL) { | |
627 | rv = -ENXIO; | |
628 | mdesc_release(hp); | |
629 | goto unreg_tty; | |
630 | } | |
631 | ||
632 | domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL); | |
633 | if (!domain) { | |
634 | rv = -ENXIO; | |
635 | mdesc_release(hp); | |
636 | goto unreg_tty; | |
637 | } | |
638 | port->domain = kstrdup(domain, GFP_KERNEL); | |
639 | ||
640 | mdesc_release(hp); | |
641 | ||
8868e44a JR |
642 | rv = sysfs_create_group(&vdev->dev.kobj, &vcc_attribute_group); |
643 | if (rv) | |
644 | goto free_domain; | |
645 | ||
f8c55335 JR |
646 | init_timer(&port->rx_timer); |
647 | port->rx_timer.function = vcc_rx_timer; | |
648 | port->rx_timer.data = port->index; | |
649 | ||
650 | init_timer(&port->tx_timer); | |
651 | port->tx_timer.function = vcc_tx_timer; | |
652 | port->tx_timer.data = port->index; | |
653 | ||
5d171050 JR |
654 | dev_set_drvdata(&vdev->dev, port); |
655 | ||
656 | /* It's possible to receive IRQs in the middle of vio_port_up. Disable | |
657 | * IRQs until the port is up. | |
658 | */ | |
659 | disable_irq_nosync(vdev->rx_irq); | |
660 | vio_port_up(&port->vio); | |
661 | enable_irq(vdev->rx_irq); | |
662 | ||
663 | return 0; | |
664 | ||
8868e44a JR |
665 | free_domain: |
666 | kfree(port->domain); | |
5d171050 JR |
667 | unreg_tty: |
668 | tty_unregister_device(vcc_tty_driver, port->index); | |
669 | free_table: | |
670 | vcc_table_remove(port->index); | |
671 | free_ldc: | |
672 | vio_ldc_free(&port->vio); | |
673 | free_port: | |
674 | kfree(name); | |
675 | kfree(port); | |
676 | ||
677 | return rv; | |
678 | } | |
679 | ||
680 | /** | |
681 | * vcc_remove() - Terminate a VCC port | |
682 | * @vdev: Pointer to VIO device of the VCC port | |
683 | * | |
684 | * Terminates a VCC port. Sets up the teardown of TTY and | |
685 | * VIO/LDC link between guest and primary domains. | |
686 | * | |
687 | * Return: status of removal | |
688 | */ | |
689 | static int vcc_remove(struct vio_dev *vdev) | |
690 | { | |
691 | struct vcc_port *port = dev_get_drvdata(&vdev->dev); | |
692 | ||
693 | if (!port) | |
694 | return -ENODEV; | |
695 | ||
f8c55335 JR |
696 | del_timer_sync(&port->rx_timer); |
697 | del_timer_sync(&port->tx_timer); | |
698 | ||
5d171050 JR |
699 | /* If there's a process with the device open, do a synchronous |
700 | * hangup of the TTY. This *may* cause the process to call close | |
701 | * asynchronously, but it's not guaranteed. | |
702 | */ | |
703 | if (port->tty) | |
704 | tty_vhangup(port->tty); | |
705 | ||
706 | /* Get exclusive reference to VCC, ensures that there are no other | |
707 | * clients to this port | |
708 | */ | |
709 | port = vcc_get(port->index, true); | |
710 | ||
711 | if (WARN_ON(!port)) | |
712 | return -ENODEV; | |
713 | ||
714 | tty_unregister_device(vcc_tty_driver, port->index); | |
715 | ||
716 | del_timer_sync(&port->vio.timer); | |
717 | vio_ldc_free(&port->vio); | |
8868e44a | 718 | sysfs_remove_group(&vdev->dev.kobj, &vcc_attribute_group); |
5d171050 | 719 | dev_set_drvdata(&vdev->dev, NULL); |
5d171050 JR |
720 | if (port->tty) { |
721 | port->removed = true; | |
722 | vcc_put(port, true); | |
723 | } else { | |
724 | vcc_table_remove(port->index); | |
725 | ||
726 | kfree(port->vio.name); | |
727 | kfree(port->domain); | |
728 | kfree(port); | |
729 | } | |
730 | ||
731 | return 0; | |
732 | } | |
733 | ||
734 | static const struct vio_device_id vcc_match[] = { | |
735 | { | |
736 | .type = "vcc-port", | |
737 | }, | |
738 | {}, | |
739 | }; | |
740 | MODULE_DEVICE_TABLE(vio, vcc_match); | |
741 | ||
742 | static struct vio_driver vcc_driver = { | |
743 | .id_table = vcc_match, | |
744 | .probe = vcc_probe, | |
745 | .remove = vcc_remove, | |
746 | .name = "vcc", | |
747 | }; | |
748 | ||
63a71744 JR |
749 | static int vcc_open(struct tty_struct *tty, struct file *vcc_file) |
750 | { | |
751 | struct vcc_port *port; | |
752 | ||
753 | if (unlikely(!tty)) { | |
754 | pr_err("VCC: open: Invalid TTY handle\n"); | |
755 | return -ENXIO; | |
756 | } | |
757 | ||
758 | if (tty->count > 1) | |
759 | return -EBUSY; | |
760 | ||
761 | port = vcc_get_ne(tty->index); | |
762 | if (unlikely(!port)) { | |
763 | pr_err("VCC: open: Failed to find VCC port\n"); | |
764 | return -ENODEV; | |
765 | } | |
766 | ||
767 | if (unlikely(!port->vio.lp)) { | |
768 | pr_err("VCC: open: LDC channel not configured\n"); | |
769 | vcc_put(port, false); | |
770 | return -EPIPE; | |
771 | } | |
772 | vccdbgl(port->vio.lp); | |
773 | ||
774 | vcc_put(port, false); | |
775 | ||
776 | if (unlikely(!tty->port)) { | |
777 | pr_err("VCC: open: TTY port not found\n"); | |
778 | return -ENXIO; | |
779 | } | |
780 | ||
781 | if (unlikely(!tty->port->ops)) { | |
782 | pr_err("VCC: open: TTY ops not defined\n"); | |
783 | return -ENXIO; | |
784 | } | |
785 | ||
786 | return tty_port_open(tty->port, tty, vcc_file); | |
787 | } | |
788 | ||
789 | static void vcc_close(struct tty_struct *tty, struct file *vcc_file) | |
790 | { | |
791 | if (unlikely(!tty)) { | |
792 | pr_err("VCC: close: Invalid TTY handle\n"); | |
793 | return; | |
794 | } | |
795 | ||
796 | if (unlikely(tty->count > 1)) | |
797 | return; | |
798 | ||
799 | if (unlikely(!tty->port)) { | |
800 | pr_err("VCC: close: TTY port not found\n"); | |
801 | return; | |
802 | } | |
803 | ||
804 | tty_port_close(tty->port, tty, vcc_file); | |
805 | } | |
806 | ||
807 | static const struct tty_operations vcc_ops = { | |
808 | .open = vcc_open, | |
809 | .close = vcc_close, | |
810 | }; | |
ce808b74 JR |
811 | |
812 | #define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW) | |
813 | ||
814 | static int vcc_tty_init(void) | |
55bd2133 | 815 | { |
ce808b74 JR |
816 | int rv; |
817 | ||
818 | pr_info("VCC: %s\n", version); | |
819 | ||
820 | vcc_tty_driver = tty_alloc_driver(VCC_MAX_PORTS, VCC_TTY_FLAGS); | |
821 | if (!vcc_tty_driver) { | |
822 | pr_err("VCC: TTY driver alloc failed\n"); | |
823 | return -ENOMEM; | |
824 | } | |
825 | ||
826 | vcc_tty_driver->driver_name = vcc_driver_name; | |
827 | vcc_tty_driver->name = vcc_device_node; | |
828 | ||
829 | vcc_tty_driver->minor_start = VCC_MINOR_START; | |
830 | vcc_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
831 | vcc_tty_driver->init_termios = vcc_tty_termios; | |
832 | ||
833 | tty_set_operations(vcc_tty_driver, &vcc_ops); | |
834 | ||
835 | rv = tty_register_driver(vcc_tty_driver); | |
836 | if (rv) { | |
837 | pr_err("VCC: TTY driver registration failed\n"); | |
838 | put_tty_driver(vcc_tty_driver); | |
839 | vcc_tty_driver = NULL; | |
840 | return rv; | |
841 | } | |
842 | ||
843 | vccdbg("VCC: TTY driver registered\n"); | |
844 | ||
55bd2133 JR |
845 | return 0; |
846 | } | |
847 | ||
ce808b74 JR |
848 | static void vcc_tty_exit(void) |
849 | { | |
850 | tty_unregister_driver(vcc_tty_driver); | |
851 | put_tty_driver(vcc_tty_driver); | |
852 | vccdbg("VCC: TTY driver unregistered\n"); | |
853 | ||
854 | vcc_tty_driver = NULL; | |
855 | } | |
856 | ||
857 | static int __init vcc_init(void) | |
858 | { | |
859 | int rv; | |
860 | ||
861 | rv = vcc_tty_init(); | |
862 | if (rv) { | |
863 | pr_err("VCC: TTY init failed\n"); | |
864 | return rv; | |
865 | } | |
866 | ||
5d171050 JR |
867 | rv = vio_register_driver(&vcc_driver); |
868 | if (rv) { | |
869 | pr_err("VCC: VIO driver registration failed\n"); | |
870 | vcc_tty_exit(); | |
871 | } else { | |
872 | vccdbg("VCC: VIO driver registered successfully\n"); | |
873 | } | |
874 | ||
ce808b74 JR |
875 | return rv; |
876 | } | |
877 | ||
55bd2133 JR |
878 | static void __exit vcc_exit(void) |
879 | { | |
5d171050 JR |
880 | vio_unregister_driver(&vcc_driver); |
881 | vccdbg("VCC: VIO driver unregistered\n"); | |
ce808b74 JR |
882 | vcc_tty_exit(); |
883 | vccdbg("VCC: TTY driver unregistered\n"); | |
55bd2133 JR |
884 | } |
885 | ||
886 | module_init(vcc_init); | |
887 | module_exit(vcc_exit); |