Commit | Line | Data |
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f16aa97d | 1 | // SPDX-License-Identifier: GPL-2.0 |
55bd2133 JR |
2 | /* vcc.c: sun4v virtual channel concentrator |
3 | * | |
4 | * Copyright (C) 2017 Oracle. All rights reserved. | |
5 | */ | |
6 | ||
5d171050 JR |
7 | #include <linux/delay.h> |
8 | #include <linux/interrupt.h> | |
55bd2133 | 9 | #include <linux/module.h> |
5d171050 | 10 | #include <linux/slab.h> |
8868e44a | 11 | #include <linux/sysfs.h> |
ce808b74 | 12 | #include <linux/tty.h> |
f8c55335 | 13 | #include <linux/tty_flip.h> |
5d171050 JR |
14 | #include <asm/vio.h> |
15 | #include <asm/ldc.h> | |
55bd2133 | 16 | |
f283ebd5 JR |
17 | MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver"); |
18 | MODULE_LICENSE("GPL"); | |
73300191 | 19 | MODULE_VERSION("1.1"); |
f283ebd5 | 20 | |
5d171050 JR |
21 | struct vcc_port { |
22 | struct vio_driver_state vio; | |
23 | ||
24 | spinlock_t lock; | |
25 | char *domain; | |
26 | struct tty_struct *tty; /* only populated while dev is open */ | |
27 | unsigned long index; /* index into the vcc_table */ | |
28 | ||
29 | u64 refcnt; | |
30 | bool excl_locked; | |
31 | ||
32 | bool removed; | |
33 | ||
34 | /* This buffer is required to support the tty write_room interface | |
35 | * and guarantee that any characters that the driver accepts will | |
36 | * be eventually sent, either immediately or later. | |
37 | */ | |
38 | int chars_in_buffer; | |
39 | struct vio_vcc buffer; | |
40 | ||
41 | struct timer_list rx_timer; | |
42 | struct timer_list tx_timer; | |
43 | }; | |
44 | ||
45 | /* Microseconds that thread will delay waiting for a vcc port ref */ | |
46 | #define VCC_REF_DELAY 100 | |
47 | ||
ce808b74 JR |
48 | #define VCC_MAX_PORTS 1024 |
49 | #define VCC_MINOR_START 0 /* must be zero */ | |
f8c55335 | 50 | #define VCC_BUFF_LEN VIO_VCC_MTU_SIZE |
ce808b74 | 51 | |
8868e44a JR |
52 | #define VCC_CTL_BREAK -1 |
53 | #define VCC_CTL_HUP -2 | |
54 | ||
ce808b74 JR |
55 | static struct tty_driver *vcc_tty_driver; |
56 | ||
5d171050 JR |
57 | static struct vcc_port *vcc_table[VCC_MAX_PORTS]; |
58 | static DEFINE_SPINLOCK(vcc_table_lock); | |
59 | ||
4c472fc0 JS |
60 | static unsigned int vcc_dbg; |
61 | static unsigned int vcc_dbg_ldc; | |
62 | static unsigned int vcc_dbg_vio; | |
f283ebd5 JR |
63 | |
64 | module_param(vcc_dbg, uint, 0664); | |
65 | module_param(vcc_dbg_ldc, uint, 0664); | |
66 | module_param(vcc_dbg_vio, uint, 0664); | |
67 | ||
68 | #define VCC_DBG_DRV 0x1 | |
69 | #define VCC_DBG_LDC 0x2 | |
70 | #define VCC_DBG_PKT 0x4 | |
71 | ||
72 | #define vccdbg(f, a...) \ | |
73 | do { \ | |
74 | if (vcc_dbg & VCC_DBG_DRV) \ | |
75 | pr_info(f, ## a); \ | |
76 | } while (0) \ | |
77 | ||
78 | #define vccdbgl(l) \ | |
79 | do { \ | |
80 | if (vcc_dbg & VCC_DBG_LDC) \ | |
81 | ldc_print(l); \ | |
82 | } while (0) \ | |
83 | ||
84 | #define vccdbgp(pkt) \ | |
85 | do { \ | |
86 | if (vcc_dbg & VCC_DBG_PKT) { \ | |
87 | int i; \ | |
88 | for (i = 0; i < pkt.tag.stype; i++) \ | |
89 | pr_info("[%c]", pkt.data[i]); \ | |
90 | } \ | |
91 | } while (0) \ | |
92 | ||
ce808b74 JR |
93 | /* Note: Be careful when adding flags to this line discipline. Don't |
94 | * add anything that will cause echoing or we'll go into recursive | |
95 | * loop echoing chars back and forth with the console drivers. | |
96 | */ | |
5bd0ea91 | 97 | static const struct ktermios vcc_tty_termios = { |
ce808b74 JR |
98 | .c_iflag = IGNBRK | IGNPAR, |
99 | .c_oflag = OPOST, | |
100 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
101 | .c_cc = INIT_C_CC, | |
102 | .c_ispeed = 38400, | |
103 | .c_ospeed = 38400 | |
104 | }; | |
105 | ||
5d171050 JR |
106 | /** |
107 | * vcc_table_add() - Add VCC port to the VCC table | |
108 | * @port: pointer to the VCC port | |
109 | * | |
110 | * Return: index of the port in the VCC table on success, | |
111 | * -1 on failure | |
112 | */ | |
113 | static int vcc_table_add(struct vcc_port *port) | |
114 | { | |
115 | unsigned long flags; | |
116 | int i; | |
117 | ||
118 | spin_lock_irqsave(&vcc_table_lock, flags); | |
119 | for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) { | |
120 | if (!vcc_table[i]) { | |
121 | vcc_table[i] = port; | |
122 | break; | |
123 | } | |
124 | } | |
125 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
126 | ||
127 | if (i < VCC_MAX_PORTS) | |
128 | return i; | |
129 | else | |
130 | return -1; | |
131 | } | |
132 | ||
133 | /** | |
134 | * vcc_table_remove() - Removes a VCC port from the VCC table | |
135 | * @index: Index into the VCC table | |
136 | */ | |
137 | static void vcc_table_remove(unsigned long index) | |
138 | { | |
139 | unsigned long flags; | |
140 | ||
141 | if (WARN_ON(index >= VCC_MAX_PORTS)) | |
142 | return; | |
143 | ||
144 | spin_lock_irqsave(&vcc_table_lock, flags); | |
145 | vcc_table[index] = NULL; | |
146 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
147 | } | |
148 | ||
149 | /** | |
150 | * vcc_get() - Gets a reference to VCC port | |
151 | * @index: Index into the VCC table | |
152 | * @excl: Indicates if an exclusive access is requested | |
153 | * | |
154 | * Return: reference to the VCC port, if found | |
155 | * NULL, if port not found | |
156 | */ | |
157 | static struct vcc_port *vcc_get(unsigned long index, bool excl) | |
158 | { | |
159 | struct vcc_port *port; | |
160 | unsigned long flags; | |
161 | ||
162 | try_again: | |
163 | spin_lock_irqsave(&vcc_table_lock, flags); | |
164 | ||
165 | port = vcc_table[index]; | |
166 | if (!port) { | |
167 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
168 | return NULL; | |
169 | } | |
170 | ||
171 | if (!excl) { | |
172 | if (port->excl_locked) { | |
173 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
174 | udelay(VCC_REF_DELAY); | |
175 | goto try_again; | |
176 | } | |
177 | port->refcnt++; | |
178 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
179 | return port; | |
180 | } | |
181 | ||
182 | if (port->refcnt) { | |
183 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
184 | /* Threads wanting exclusive access will wait half the time, | |
185 | * probably giving them higher priority in the case of | |
186 | * multiple waiters. | |
187 | */ | |
188 | udelay(VCC_REF_DELAY/2); | |
189 | goto try_again; | |
190 | } | |
191 | ||
192 | port->refcnt++; | |
193 | port->excl_locked = true; | |
194 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
195 | ||
196 | return port; | |
197 | } | |
198 | ||
199 | /** | |
200 | * vcc_put() - Returns a reference to VCC port | |
201 | * @port: pointer to VCC port | |
202 | * @excl: Indicates if the returned reference is an exclusive reference | |
203 | * | |
204 | * Note: It's the caller's responsibility to ensure the correct value | |
205 | * for the excl flag | |
206 | */ | |
207 | static void vcc_put(struct vcc_port *port, bool excl) | |
208 | { | |
209 | unsigned long flags; | |
210 | ||
211 | if (!port) | |
212 | return; | |
213 | ||
214 | spin_lock_irqsave(&vcc_table_lock, flags); | |
215 | ||
216 | /* check if caller attempted to put with the wrong flags */ | |
217 | if (WARN_ON((excl && !port->excl_locked) || | |
218 | (!excl && port->excl_locked))) | |
219 | goto done; | |
220 | ||
221 | port->refcnt--; | |
222 | ||
223 | if (excl) | |
224 | port->excl_locked = false; | |
225 | ||
226 | done: | |
227 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
228 | } | |
229 | ||
230 | /** | |
231 | * vcc_get_ne() - Get a non-exclusive reference to VCC port | |
232 | * @index: Index into the VCC table | |
233 | * | |
234 | * Gets a non-exclusive reference to VCC port, if it's not removed | |
235 | * | |
236 | * Return: pointer to the VCC port, if found | |
237 | * NULL, if port not found | |
238 | */ | |
239 | static struct vcc_port *vcc_get_ne(unsigned long index) | |
240 | { | |
241 | struct vcc_port *port; | |
242 | ||
243 | port = vcc_get(index, false); | |
244 | ||
245 | if (port && port->removed) { | |
246 | vcc_put(port, false); | |
247 | return NULL; | |
248 | } | |
249 | ||
250 | return port; | |
251 | } | |
252 | ||
f8c55335 JR |
253 | static void vcc_kick_rx(struct vcc_port *port) |
254 | { | |
255 | struct vio_driver_state *vio = &port->vio; | |
256 | ||
257 | assert_spin_locked(&port->lock); | |
258 | ||
259 | if (!timer_pending(&port->rx_timer) && !port->removed) { | |
260 | disable_irq_nosync(vio->vdev->rx_irq); | |
261 | port->rx_timer.expires = (jiffies + 1); | |
262 | add_timer(&port->rx_timer); | |
263 | } | |
264 | } | |
265 | ||
266 | static void vcc_kick_tx(struct vcc_port *port) | |
267 | { | |
268 | assert_spin_locked(&port->lock); | |
269 | ||
270 | if (!timer_pending(&port->tx_timer) && !port->removed) { | |
271 | port->tx_timer.expires = (jiffies + 1); | |
272 | add_timer(&port->tx_timer); | |
273 | } | |
274 | } | |
275 | ||
276 | static int vcc_rx_check(struct tty_struct *tty, int size) | |
277 | { | |
278 | if (WARN_ON(!tty || !tty->port)) | |
279 | return 1; | |
280 | ||
281 | /* tty_buffer_request_room won't sleep because it uses | |
282 | * GFP_ATOMIC flag to allocate buffer | |
283 | */ | |
284 | if (test_bit(TTY_THROTTLED, &tty->flags) || | |
285 | (tty_buffer_request_room(tty->port, VCC_BUFF_LEN) < VCC_BUFF_LEN)) | |
286 | return 0; | |
287 | ||
288 | return 1; | |
289 | } | |
290 | ||
291 | static int vcc_rx(struct tty_struct *tty, char *buf, int size) | |
292 | { | |
293 | int len = 0; | |
294 | ||
295 | if (WARN_ON(!tty || !tty->port)) | |
296 | return len; | |
297 | ||
298 | len = tty_insert_flip_string(tty->port, buf, size); | |
299 | if (len) | |
300 | tty_flip_buffer_push(tty->port); | |
301 | ||
302 | return len; | |
303 | } | |
304 | ||
305 | static int vcc_ldc_read(struct vcc_port *port) | |
306 | { | |
307 | struct vio_driver_state *vio = &port->vio; | |
308 | struct tty_struct *tty; | |
309 | struct vio_vcc pkt; | |
310 | int rv = 0; | |
311 | ||
312 | tty = port->tty; | |
313 | if (!tty) { | |
314 | rv = ldc_rx_reset(vio->lp); | |
315 | vccdbg("VCC: reset rx q: rv=%d\n", rv); | |
316 | goto done; | |
317 | } | |
318 | ||
319 | /* Read as long as LDC has incoming data. */ | |
320 | while (1) { | |
321 | if (!vcc_rx_check(tty, VIO_VCC_MTU_SIZE)) { | |
322 | vcc_kick_rx(port); | |
323 | break; | |
324 | } | |
325 | ||
326 | vccdbgl(vio->lp); | |
327 | ||
328 | rv = ldc_read(vio->lp, &pkt, sizeof(pkt)); | |
329 | if (rv <= 0) | |
330 | break; | |
331 | ||
332 | vccdbg("VCC: ldc_read()=%d\n", rv); | |
333 | vccdbg("TAG [%02x:%02x:%04x:%08x]\n", | |
334 | pkt.tag.type, pkt.tag.stype, | |
335 | pkt.tag.stype_env, pkt.tag.sid); | |
336 | ||
337 | if (pkt.tag.type == VIO_TYPE_DATA) { | |
338 | vccdbgp(pkt); | |
339 | /* vcc_rx_check ensures memory availability */ | |
340 | vcc_rx(tty, pkt.data, pkt.tag.stype); | |
341 | } else { | |
342 | pr_err("VCC: unknown msg [%02x:%02x:%04x:%08x]\n", | |
343 | pkt.tag.type, pkt.tag.stype, | |
344 | pkt.tag.stype_env, pkt.tag.sid); | |
345 | rv = -ECONNRESET; | |
346 | break; | |
347 | } | |
348 | ||
349 | WARN_ON(rv != LDC_PACKET_SIZE); | |
350 | } | |
351 | ||
352 | done: | |
353 | return rv; | |
354 | } | |
355 | ||
4790b6dc | 356 | static void vcc_rx_timer(struct timer_list *t) |
f8c55335 | 357 | { |
4790b6dc | 358 | struct vcc_port *port = from_timer(port, t, rx_timer); |
f8c55335 | 359 | struct vio_driver_state *vio; |
f8c55335 JR |
360 | unsigned long flags; |
361 | int rv; | |
362 | ||
f8c55335 JR |
363 | spin_lock_irqsave(&port->lock, flags); |
364 | port->rx_timer.expires = 0; | |
365 | ||
366 | vio = &port->vio; | |
367 | ||
368 | enable_irq(vio->vdev->rx_irq); | |
369 | ||
370 | if (!port->tty || port->removed) | |
371 | goto done; | |
372 | ||
373 | rv = vcc_ldc_read(port); | |
374 | if (rv == -ECONNRESET) | |
375 | vio_conn_reset(vio); | |
376 | ||
377 | done: | |
378 | spin_unlock_irqrestore(&port->lock, flags); | |
379 | vcc_put(port, false); | |
380 | } | |
381 | ||
4790b6dc | 382 | static void vcc_tx_timer(struct timer_list *t) |
f8c55335 | 383 | { |
4790b6dc | 384 | struct vcc_port *port = from_timer(port, t, tx_timer); |
f8c55335 JR |
385 | struct vio_vcc *pkt; |
386 | unsigned long flags; | |
387 | int tosend = 0; | |
388 | int rv; | |
389 | ||
f8c55335 JR |
390 | spin_lock_irqsave(&port->lock, flags); |
391 | port->tx_timer.expires = 0; | |
392 | ||
393 | if (!port->tty || port->removed) | |
394 | goto done; | |
395 | ||
396 | tosend = min(VCC_BUFF_LEN, port->chars_in_buffer); | |
397 | if (!tosend) | |
398 | goto done; | |
399 | ||
400 | pkt = &port->buffer; | |
401 | pkt->tag.type = VIO_TYPE_DATA; | |
402 | pkt->tag.stype = tosend; | |
403 | vccdbgl(port->vio.lp); | |
404 | ||
405 | rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend)); | |
406 | WARN_ON(!rv); | |
407 | ||
408 | if (rv < 0) { | |
409 | vccdbg("VCC: ldc_write()=%d\n", rv); | |
410 | vcc_kick_tx(port); | |
411 | } else { | |
412 | struct tty_struct *tty = port->tty; | |
413 | ||
414 | port->chars_in_buffer = 0; | |
415 | if (tty) | |
416 | tty_wakeup(tty); | |
417 | } | |
418 | ||
419 | done: | |
420 | spin_unlock_irqrestore(&port->lock, flags); | |
421 | vcc_put(port, false); | |
422 | } | |
423 | ||
103b9b0b JR |
424 | /** |
425 | * vcc_event() - LDC event processing engine | |
426 | * @arg: VCC private data | |
427 | * @event: LDC event | |
428 | * | |
429 | * Handles LDC events for VCC | |
430 | */ | |
5d171050 JR |
431 | static void vcc_event(void *arg, int event) |
432 | { | |
103b9b0b JR |
433 | struct vio_driver_state *vio; |
434 | struct vcc_port *port; | |
435 | unsigned long flags; | |
436 | int rv; | |
437 | ||
438 | port = arg; | |
439 | vio = &port->vio; | |
440 | ||
441 | spin_lock_irqsave(&port->lock, flags); | |
442 | ||
443 | switch (event) { | |
444 | case LDC_EVENT_RESET: | |
445 | case LDC_EVENT_UP: | |
446 | vio_link_state_change(vio, event); | |
447 | break; | |
448 | ||
449 | case LDC_EVENT_DATA_READY: | |
450 | rv = vcc_ldc_read(port); | |
451 | if (rv == -ECONNRESET) | |
452 | vio_conn_reset(vio); | |
453 | break; | |
454 | ||
455 | default: | |
456 | pr_err("VCC: unexpected LDC event(%d)\n", event); | |
457 | } | |
458 | ||
459 | spin_unlock_irqrestore(&port->lock, flags); | |
5d171050 JR |
460 | } |
461 | ||
462 | static struct ldc_channel_config vcc_ldc_cfg = { | |
463 | .event = vcc_event, | |
464 | .mtu = VIO_VCC_MTU_SIZE, | |
465 | .mode = LDC_MODE_RAW, | |
466 | .debug = 0, | |
467 | }; | |
468 | ||
469 | /* Ordered from largest major to lowest */ | |
470 | static struct vio_version vcc_versions[] = { | |
471 | { .major = 1, .minor = 0 }, | |
472 | }; | |
473 | ||
8f03f948 JR |
474 | static struct tty_port_operations vcc_port_ops = { 0 }; |
475 | ||
2877389f ZL |
476 | static ssize_t domain_show(struct device *dev, |
477 | struct device_attribute *attr, | |
478 | char *buf) | |
8868e44a JR |
479 | { |
480 | struct vcc_port *port; | |
481 | int rv; | |
482 | ||
483 | port = dev_get_drvdata(dev); | |
484 | if (!port) | |
485 | return -ENODEV; | |
486 | ||
487 | rv = scnprintf(buf, PAGE_SIZE, "%s\n", port->domain); | |
488 | ||
489 | return rv; | |
490 | } | |
491 | ||
492 | static int vcc_send_ctl(struct vcc_port *port, int ctl) | |
493 | { | |
494 | struct vio_vcc pkt; | |
495 | int rv; | |
496 | ||
497 | pkt.tag.type = VIO_TYPE_CTRL; | |
498 | pkt.tag.sid = ctl; | |
499 | pkt.tag.stype = 0; | |
500 | ||
501 | rv = ldc_write(port->vio.lp, &pkt, sizeof(pkt.tag)); | |
502 | WARN_ON(!rv); | |
503 | vccdbg("VCC: ldc_write(%ld)=%d\n", sizeof(pkt.tag), rv); | |
504 | ||
505 | return rv; | |
506 | } | |
507 | ||
2877389f ZL |
508 | static ssize_t break_store(struct device *dev, |
509 | struct device_attribute *attr, | |
510 | const char *buf, size_t count) | |
8868e44a JR |
511 | { |
512 | struct vcc_port *port; | |
513 | unsigned long flags; | |
514 | int rv = count; | |
515 | int brk; | |
516 | ||
517 | port = dev_get_drvdata(dev); | |
518 | if (!port) | |
519 | return -ENODEV; | |
520 | ||
521 | spin_lock_irqsave(&port->lock, flags); | |
522 | ||
523 | if (sscanf(buf, "%ud", &brk) != 1 || brk != 1) | |
524 | rv = -EINVAL; | |
525 | else if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0) | |
f8c55335 | 526 | vcc_kick_tx(port); |
8868e44a JR |
527 | |
528 | spin_unlock_irqrestore(&port->lock, flags); | |
529 | ||
530 | return rv; | |
531 | } | |
532 | ||
2877389f ZL |
533 | static DEVICE_ATTR_ADMIN_RO(domain); |
534 | static DEVICE_ATTR_WO(break); | |
8868e44a JR |
535 | |
536 | static struct attribute *vcc_sysfs_entries[] = { | |
537 | &dev_attr_domain.attr, | |
538 | &dev_attr_break.attr, | |
539 | NULL | |
540 | }; | |
541 | ||
542 | static struct attribute_group vcc_attribute_group = { | |
543 | .name = NULL, | |
544 | .attrs = vcc_sysfs_entries, | |
545 | }; | |
546 | ||
5d171050 JR |
547 | /** |
548 | * vcc_probe() - Initialize VCC port | |
549 | * @vdev: Pointer to VIO device of the new VCC port | |
550 | * @id: VIO device ID | |
551 | * | |
552 | * Initializes a VCC port to receive serial console data from | |
553 | * the guest domain. Sets up a TTY end point on the control | |
554 | * domain. Sets up VIO/LDC link between the guest & control | |
555 | * domain endpoints. | |
556 | * | |
557 | * Return: status of the probe | |
558 | */ | |
559 | static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id) | |
560 | { | |
561 | struct mdesc_handle *hp; | |
562 | struct vcc_port *port; | |
563 | struct device *dev; | |
564 | const char *domain; | |
565 | char *name; | |
566 | u64 node; | |
567 | int rv; | |
568 | ||
569 | vccdbg("VCC: name=%s\n", dev_name(&vdev->dev)); | |
570 | ||
571 | if (!vcc_tty_driver) { | |
572 | pr_err("VCC: TTY driver not registered\n"); | |
573 | return -ENODEV; | |
574 | } | |
575 | ||
576 | port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL); | |
577 | if (!port) | |
578 | return -ENOMEM; | |
579 | ||
580 | name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL); | |
581 | ||
582 | rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions, | |
583 | ARRAY_SIZE(vcc_versions), NULL, name); | |
584 | if (rv) | |
585 | goto free_port; | |
586 | ||
587 | port->vio.debug = vcc_dbg_vio; | |
588 | vcc_ldc_cfg.debug = vcc_dbg_ldc; | |
589 | ||
590 | rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port); | |
591 | if (rv) | |
592 | goto free_port; | |
593 | ||
594 | spin_lock_init(&port->lock); | |
595 | ||
596 | port->index = vcc_table_add(port); | |
597 | if (port->index == -1) { | |
598 | pr_err("VCC: no more TTY indices left for allocation\n"); | |
ff62255a | 599 | rv = -ENOMEM; |
5d171050 JR |
600 | goto free_ldc; |
601 | } | |
602 | ||
603 | /* Register the device using VCC table index as TTY index */ | |
604 | dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev); | |
605 | if (IS_ERR(dev)) { | |
606 | rv = PTR_ERR(dev); | |
607 | goto free_table; | |
608 | } | |
609 | ||
610 | hp = mdesc_grab(); | |
611 | ||
612 | node = vio_vdev_node(hp, vdev); | |
613 | if (node == MDESC_NODE_NULL) { | |
614 | rv = -ENXIO; | |
615 | mdesc_release(hp); | |
616 | goto unreg_tty; | |
617 | } | |
618 | ||
619 | domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL); | |
620 | if (!domain) { | |
621 | rv = -ENXIO; | |
622 | mdesc_release(hp); | |
623 | goto unreg_tty; | |
624 | } | |
625 | port->domain = kstrdup(domain, GFP_KERNEL); | |
626 | ||
627 | mdesc_release(hp); | |
628 | ||
8868e44a JR |
629 | rv = sysfs_create_group(&vdev->dev.kobj, &vcc_attribute_group); |
630 | if (rv) | |
631 | goto free_domain; | |
632 | ||
4790b6dc KC |
633 | timer_setup(&port->rx_timer, vcc_rx_timer, 0); |
634 | timer_setup(&port->tx_timer, vcc_tx_timer, 0); | |
f8c55335 | 635 | |
5d171050 JR |
636 | dev_set_drvdata(&vdev->dev, port); |
637 | ||
638 | /* It's possible to receive IRQs in the middle of vio_port_up. Disable | |
639 | * IRQs until the port is up. | |
640 | */ | |
641 | disable_irq_nosync(vdev->rx_irq); | |
642 | vio_port_up(&port->vio); | |
643 | enable_irq(vdev->rx_irq); | |
644 | ||
645 | return 0; | |
646 | ||
8868e44a JR |
647 | free_domain: |
648 | kfree(port->domain); | |
5d171050 JR |
649 | unreg_tty: |
650 | tty_unregister_device(vcc_tty_driver, port->index); | |
651 | free_table: | |
652 | vcc_table_remove(port->index); | |
653 | free_ldc: | |
654 | vio_ldc_free(&port->vio); | |
655 | free_port: | |
656 | kfree(name); | |
657 | kfree(port); | |
658 | ||
659 | return rv; | |
660 | } | |
661 | ||
662 | /** | |
663 | * vcc_remove() - Terminate a VCC port | |
664 | * @vdev: Pointer to VIO device of the VCC port | |
665 | * | |
666 | * Terminates a VCC port. Sets up the teardown of TTY and | |
667 | * VIO/LDC link between guest and primary domains. | |
668 | * | |
669 | * Return: status of removal | |
670 | */ | |
1553573c | 671 | static void vcc_remove(struct vio_dev *vdev) |
5d171050 JR |
672 | { |
673 | struct vcc_port *port = dev_get_drvdata(&vdev->dev); | |
674 | ||
f8c55335 JR |
675 | del_timer_sync(&port->rx_timer); |
676 | del_timer_sync(&port->tx_timer); | |
677 | ||
5d171050 JR |
678 | /* If there's a process with the device open, do a synchronous |
679 | * hangup of the TTY. This *may* cause the process to call close | |
680 | * asynchronously, but it's not guaranteed. | |
681 | */ | |
682 | if (port->tty) | |
683 | tty_vhangup(port->tty); | |
684 | ||
685 | /* Get exclusive reference to VCC, ensures that there are no other | |
63e34e70 | 686 | * clients to this port. This cannot fail. |
5d171050 | 687 | */ |
63e34e70 | 688 | vcc_get(port->index, true); |
5d171050 JR |
689 | |
690 | tty_unregister_device(vcc_tty_driver, port->index); | |
691 | ||
692 | del_timer_sync(&port->vio.timer); | |
693 | vio_ldc_free(&port->vio); | |
8868e44a | 694 | sysfs_remove_group(&vdev->dev.kobj, &vcc_attribute_group); |
5d171050 | 695 | dev_set_drvdata(&vdev->dev, NULL); |
5d171050 JR |
696 | if (port->tty) { |
697 | port->removed = true; | |
698 | vcc_put(port, true); | |
699 | } else { | |
700 | vcc_table_remove(port->index); | |
701 | ||
702 | kfree(port->vio.name); | |
703 | kfree(port->domain); | |
704 | kfree(port); | |
705 | } | |
5d171050 JR |
706 | } |
707 | ||
708 | static const struct vio_device_id vcc_match[] = { | |
709 | { | |
710 | .type = "vcc-port", | |
711 | }, | |
712 | {}, | |
713 | }; | |
714 | MODULE_DEVICE_TABLE(vio, vcc_match); | |
715 | ||
716 | static struct vio_driver vcc_driver = { | |
717 | .id_table = vcc_match, | |
718 | .probe = vcc_probe, | |
719 | .remove = vcc_remove, | |
720 | .name = "vcc", | |
721 | }; | |
722 | ||
63a71744 JR |
723 | static int vcc_open(struct tty_struct *tty, struct file *vcc_file) |
724 | { | |
725 | struct vcc_port *port; | |
726 | ||
63a71744 JR |
727 | if (tty->count > 1) |
728 | return -EBUSY; | |
729 | ||
730 | port = vcc_get_ne(tty->index); | |
731 | if (unlikely(!port)) { | |
732 | pr_err("VCC: open: Failed to find VCC port\n"); | |
733 | return -ENODEV; | |
734 | } | |
735 | ||
736 | if (unlikely(!port->vio.lp)) { | |
737 | pr_err("VCC: open: LDC channel not configured\n"); | |
738 | vcc_put(port, false); | |
739 | return -EPIPE; | |
740 | } | |
741 | vccdbgl(port->vio.lp); | |
742 | ||
743 | vcc_put(port, false); | |
744 | ||
745 | if (unlikely(!tty->port)) { | |
746 | pr_err("VCC: open: TTY port not found\n"); | |
747 | return -ENXIO; | |
748 | } | |
749 | ||
750 | if (unlikely(!tty->port->ops)) { | |
751 | pr_err("VCC: open: TTY ops not defined\n"); | |
752 | return -ENXIO; | |
753 | } | |
754 | ||
755 | return tty_port_open(tty->port, tty, vcc_file); | |
756 | } | |
757 | ||
758 | static void vcc_close(struct tty_struct *tty, struct file *vcc_file) | |
759 | { | |
63a71744 JR |
760 | if (unlikely(tty->count > 1)) |
761 | return; | |
762 | ||
763 | if (unlikely(!tty->port)) { | |
764 | pr_err("VCC: close: TTY port not found\n"); | |
765 | return; | |
766 | } | |
767 | ||
768 | tty_port_close(tty->port, tty, vcc_file); | |
769 | } | |
770 | ||
6a3ff25b JR |
771 | static void vcc_ldc_hup(struct vcc_port *port) |
772 | { | |
773 | unsigned long flags; | |
774 | ||
775 | spin_lock_irqsave(&port->lock, flags); | |
776 | ||
777 | if (vcc_send_ctl(port, VCC_CTL_HUP) < 0) | |
778 | vcc_kick_tx(port); | |
779 | ||
780 | spin_unlock_irqrestore(&port->lock, flags); | |
781 | } | |
782 | ||
783 | static void vcc_hangup(struct tty_struct *tty) | |
784 | { | |
785 | struct vcc_port *port; | |
786 | ||
6a3ff25b JR |
787 | port = vcc_get_ne(tty->index); |
788 | if (unlikely(!port)) { | |
789 | pr_err("VCC: hangup: Failed to find VCC port\n"); | |
790 | return; | |
791 | } | |
792 | ||
793 | if (unlikely(!tty->port)) { | |
794 | pr_err("VCC: hangup: TTY port not found\n"); | |
795 | vcc_put(port, false); | |
796 | return; | |
797 | } | |
798 | ||
799 | vcc_ldc_hup(port); | |
800 | ||
801 | vcc_put(port, false); | |
802 | ||
803 | tty_port_hangup(tty->port); | |
804 | } | |
805 | ||
cf045260 JR |
806 | static int vcc_write(struct tty_struct *tty, const unsigned char *buf, |
807 | int count) | |
808 | { | |
809 | struct vcc_port *port; | |
810 | struct vio_vcc *pkt; | |
811 | unsigned long flags; | |
812 | int total_sent = 0; | |
813 | int tosend = 0; | |
814 | int rv = -EINVAL; | |
815 | ||
cf045260 JR |
816 | port = vcc_get_ne(tty->index); |
817 | if (unlikely(!port)) { | |
818 | pr_err("VCC: write: Failed to find VCC port"); | |
819 | return -ENODEV; | |
820 | } | |
821 | ||
822 | spin_lock_irqsave(&port->lock, flags); | |
823 | ||
824 | pkt = &port->buffer; | |
825 | pkt->tag.type = VIO_TYPE_DATA; | |
826 | ||
827 | while (count > 0) { | |
828 | /* Minimum of data to write and space available */ | |
829 | tosend = min(count, (VCC_BUFF_LEN - port->chars_in_buffer)); | |
830 | ||
831 | if (!tosend) | |
832 | break; | |
833 | ||
834 | memcpy(&pkt->data[port->chars_in_buffer], &buf[total_sent], | |
835 | tosend); | |
836 | port->chars_in_buffer += tosend; | |
837 | pkt->tag.stype = tosend; | |
838 | ||
839 | vccdbg("TAG [%02x:%02x:%04x:%08x]\n", pkt->tag.type, | |
840 | pkt->tag.stype, pkt->tag.stype_env, pkt->tag.sid); | |
841 | vccdbg("DATA [%s]\n", pkt->data); | |
842 | vccdbgl(port->vio.lp); | |
843 | ||
844 | /* Since we know we have enough room in VCC buffer for tosend | |
845 | * we record that it was sent regardless of whether the | |
846 | * hypervisor actually took it because we have it buffered. | |
847 | */ | |
848 | rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend)); | |
849 | vccdbg("VCC: write: ldc_write(%d)=%d\n", | |
850 | (VIO_TAG_SIZE + tosend), rv); | |
851 | ||
852 | total_sent += tosend; | |
853 | count -= tosend; | |
854 | if (rv < 0) { | |
855 | vcc_kick_tx(port); | |
856 | break; | |
857 | } | |
858 | ||
859 | port->chars_in_buffer = 0; | |
860 | } | |
861 | ||
862 | spin_unlock_irqrestore(&port->lock, flags); | |
863 | ||
864 | vcc_put(port, false); | |
865 | ||
866 | vccdbg("VCC: write: total=%d rv=%d", total_sent, rv); | |
867 | ||
868 | return total_sent ? total_sent : rv; | |
869 | } | |
870 | ||
03b3b1a2 | 871 | static unsigned int vcc_write_room(struct tty_struct *tty) |
cf045260 JR |
872 | { |
873 | struct vcc_port *port; | |
03b3b1a2 | 874 | unsigned int num; |
cf045260 | 875 | |
cf045260 JR |
876 | port = vcc_get_ne(tty->index); |
877 | if (unlikely(!port)) { | |
878 | pr_err("VCC: write_room: Failed to find VCC port\n"); | |
6bfbfcfc | 879 | return 0; |
cf045260 JR |
880 | } |
881 | ||
882 | num = VCC_BUFF_LEN - port->chars_in_buffer; | |
883 | ||
884 | vcc_put(port, false); | |
885 | ||
886 | return num; | |
887 | } | |
888 | ||
fff4ef17 | 889 | static unsigned int vcc_chars_in_buffer(struct tty_struct *tty) |
aeee7deb JR |
890 | { |
891 | struct vcc_port *port; | |
fff4ef17 | 892 | unsigned int num; |
aeee7deb | 893 | |
aeee7deb JR |
894 | port = vcc_get_ne(tty->index); |
895 | if (unlikely(!port)) { | |
896 | pr_err("VCC: chars_in_buffer: Failed to find VCC port\n"); | |
10eb63e5 | 897 | return 0; |
aeee7deb JR |
898 | } |
899 | ||
900 | num = port->chars_in_buffer; | |
901 | ||
902 | vcc_put(port, false); | |
903 | ||
904 | return num; | |
905 | } | |
906 | ||
e942e577 JR |
907 | static int vcc_break_ctl(struct tty_struct *tty, int state) |
908 | { | |
909 | struct vcc_port *port; | |
910 | unsigned long flags; | |
911 | ||
e942e577 JR |
912 | port = vcc_get_ne(tty->index); |
913 | if (unlikely(!port)) { | |
914 | pr_err("VCC: break_ctl: Failed to find VCC port\n"); | |
915 | return -ENODEV; | |
916 | } | |
917 | ||
918 | /* Turn off break */ | |
919 | if (state == 0) { | |
920 | vcc_put(port, false); | |
921 | return 0; | |
922 | } | |
923 | ||
924 | spin_lock_irqsave(&port->lock, flags); | |
925 | ||
926 | if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0) | |
927 | vcc_kick_tx(port); | |
928 | ||
929 | spin_unlock_irqrestore(&port->lock, flags); | |
930 | ||
931 | vcc_put(port, false); | |
932 | ||
933 | return 0; | |
934 | } | |
935 | ||
8f03f948 JR |
936 | static int vcc_install(struct tty_driver *driver, struct tty_struct *tty) |
937 | { | |
938 | struct vcc_port *port_vcc; | |
939 | struct tty_port *port_tty; | |
940 | int ret; | |
941 | ||
8f03f948 JR |
942 | if (tty->index >= VCC_MAX_PORTS) |
943 | return -EINVAL; | |
944 | ||
945 | ret = tty_standard_install(driver, tty); | |
946 | if (ret) | |
947 | return ret; | |
948 | ||
949 | port_tty = kzalloc(sizeof(struct tty_port), GFP_KERNEL); | |
950 | if (!port_tty) | |
951 | return -ENOMEM; | |
952 | ||
953 | port_vcc = vcc_get(tty->index, true); | |
954 | if (!port_vcc) { | |
955 | pr_err("VCC: install: Failed to find VCC port\n"); | |
956 | tty->port = NULL; | |
957 | kfree(port_tty); | |
958 | return -ENODEV; | |
959 | } | |
960 | ||
961 | tty_port_init(port_tty); | |
962 | port_tty->ops = &vcc_port_ops; | |
963 | tty->port = port_tty; | |
964 | ||
965 | port_vcc->tty = tty; | |
966 | ||
967 | vcc_put(port_vcc, true); | |
968 | ||
969 | return 0; | |
970 | } | |
971 | ||
972 | static void vcc_cleanup(struct tty_struct *tty) | |
973 | { | |
974 | struct vcc_port *port; | |
975 | ||
8f03f948 JR |
976 | port = vcc_get(tty->index, true); |
977 | if (port) { | |
978 | port->tty = NULL; | |
979 | ||
980 | if (port->removed) { | |
981 | vcc_table_remove(tty->index); | |
982 | kfree(port->vio.name); | |
983 | kfree(port->domain); | |
984 | kfree(port); | |
985 | } else { | |
986 | vcc_put(port, true); | |
987 | } | |
988 | } | |
989 | ||
990 | tty_port_destroy(tty->port); | |
991 | kfree(tty->port); | |
992 | tty->port = NULL; | |
993 | } | |
994 | ||
63a71744 | 995 | static const struct tty_operations vcc_ops = { |
aeee7deb JR |
996 | .open = vcc_open, |
997 | .close = vcc_close, | |
998 | .hangup = vcc_hangup, | |
999 | .write = vcc_write, | |
1000 | .write_room = vcc_write_room, | |
1001 | .chars_in_buffer = vcc_chars_in_buffer, | |
e942e577 | 1002 | .break_ctl = vcc_break_ctl, |
8f03f948 JR |
1003 | .install = vcc_install, |
1004 | .cleanup = vcc_cleanup, | |
63a71744 | 1005 | }; |
ce808b74 JR |
1006 | |
1007 | #define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW) | |
1008 | ||
1009 | static int vcc_tty_init(void) | |
55bd2133 | 1010 | { |
ce808b74 JR |
1011 | int rv; |
1012 | ||
ce808b74 | 1013 | vcc_tty_driver = tty_alloc_driver(VCC_MAX_PORTS, VCC_TTY_FLAGS); |
c6b4ee9e | 1014 | if (IS_ERR(vcc_tty_driver)) { |
ce808b74 | 1015 | pr_err("VCC: TTY driver alloc failed\n"); |
c6b4ee9e | 1016 | return PTR_ERR(vcc_tty_driver); |
ce808b74 JR |
1017 | } |
1018 | ||
9af6f74d JS |
1019 | vcc_tty_driver->driver_name = "vcc"; |
1020 | vcc_tty_driver->name = "vcc"; | |
ce808b74 JR |
1021 | |
1022 | vcc_tty_driver->minor_start = VCC_MINOR_START; | |
1023 | vcc_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
1024 | vcc_tty_driver->init_termios = vcc_tty_termios; | |
1025 | ||
1026 | tty_set_operations(vcc_tty_driver, &vcc_ops); | |
1027 | ||
1028 | rv = tty_register_driver(vcc_tty_driver); | |
1029 | if (rv) { | |
1030 | pr_err("VCC: TTY driver registration failed\n"); | |
9f90a4dd | 1031 | tty_driver_kref_put(vcc_tty_driver); |
ce808b74 JR |
1032 | vcc_tty_driver = NULL; |
1033 | return rv; | |
1034 | } | |
1035 | ||
1036 | vccdbg("VCC: TTY driver registered\n"); | |
1037 | ||
55bd2133 JR |
1038 | return 0; |
1039 | } | |
1040 | ||
ce808b74 JR |
1041 | static void vcc_tty_exit(void) |
1042 | { | |
1043 | tty_unregister_driver(vcc_tty_driver); | |
9f90a4dd | 1044 | tty_driver_kref_put(vcc_tty_driver); |
ce808b74 JR |
1045 | vccdbg("VCC: TTY driver unregistered\n"); |
1046 | ||
1047 | vcc_tty_driver = NULL; | |
1048 | } | |
1049 | ||
1050 | static int __init vcc_init(void) | |
1051 | { | |
1052 | int rv; | |
1053 | ||
1054 | rv = vcc_tty_init(); | |
1055 | if (rv) { | |
1056 | pr_err("VCC: TTY init failed\n"); | |
1057 | return rv; | |
1058 | } | |
1059 | ||
5d171050 JR |
1060 | rv = vio_register_driver(&vcc_driver); |
1061 | if (rv) { | |
1062 | pr_err("VCC: VIO driver registration failed\n"); | |
1063 | vcc_tty_exit(); | |
1064 | } else { | |
1065 | vccdbg("VCC: VIO driver registered successfully\n"); | |
1066 | } | |
1067 | ||
ce808b74 JR |
1068 | return rv; |
1069 | } | |
1070 | ||
55bd2133 JR |
1071 | static void __exit vcc_exit(void) |
1072 | { | |
5d171050 JR |
1073 | vio_unregister_driver(&vcc_driver); |
1074 | vccdbg("VCC: VIO driver unregistered\n"); | |
ce808b74 JR |
1075 | vcc_tty_exit(); |
1076 | vccdbg("VCC: TTY driver unregistered\n"); | |
55bd2133 JR |
1077 | } |
1078 | ||
1079 | module_init(vcc_init); | |
1080 | module_exit(vcc_exit); |