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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 | #define DRV_MODULE_NAME "vcc" |
18 | #define DRV_MODULE_VERSION "1.1" | |
19 | #define DRV_MODULE_RELDATE "July 1, 2017" | |
20 | ||
ce808b74 JR |
21 | static char version[] = |
22 | DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")"; | |
23 | ||
f283ebd5 JR |
24 | MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver"); |
25 | MODULE_LICENSE("GPL"); | |
26 | MODULE_VERSION(DRV_MODULE_VERSION); | |
27 | ||
5d171050 JR |
28 | struct vcc_port { |
29 | struct vio_driver_state vio; | |
30 | ||
31 | spinlock_t lock; | |
32 | char *domain; | |
33 | struct tty_struct *tty; /* only populated while dev is open */ | |
34 | unsigned long index; /* index into the vcc_table */ | |
35 | ||
36 | u64 refcnt; | |
37 | bool excl_locked; | |
38 | ||
39 | bool removed; | |
40 | ||
41 | /* This buffer is required to support the tty write_room interface | |
42 | * and guarantee that any characters that the driver accepts will | |
43 | * be eventually sent, either immediately or later. | |
44 | */ | |
45 | int chars_in_buffer; | |
46 | struct vio_vcc buffer; | |
47 | ||
48 | struct timer_list rx_timer; | |
49 | struct timer_list tx_timer; | |
50 | }; | |
51 | ||
52 | /* Microseconds that thread will delay waiting for a vcc port ref */ | |
53 | #define VCC_REF_DELAY 100 | |
54 | ||
ce808b74 JR |
55 | #define VCC_MAX_PORTS 1024 |
56 | #define VCC_MINOR_START 0 /* must be zero */ | |
f8c55335 | 57 | #define VCC_BUFF_LEN VIO_VCC_MTU_SIZE |
ce808b74 | 58 | |
8868e44a JR |
59 | #define VCC_CTL_BREAK -1 |
60 | #define VCC_CTL_HUP -2 | |
61 | ||
ce808b74 JR |
62 | static const char vcc_driver_name[] = "vcc"; |
63 | static const char vcc_device_node[] = "vcc"; | |
64 | static struct tty_driver *vcc_tty_driver; | |
65 | ||
5d171050 JR |
66 | static struct vcc_port *vcc_table[VCC_MAX_PORTS]; |
67 | static DEFINE_SPINLOCK(vcc_table_lock); | |
68 | ||
f283ebd5 JR |
69 | int vcc_dbg; |
70 | int vcc_dbg_ldc; | |
71 | int vcc_dbg_vio; | |
72 | ||
73 | module_param(vcc_dbg, uint, 0664); | |
74 | module_param(vcc_dbg_ldc, uint, 0664); | |
75 | module_param(vcc_dbg_vio, uint, 0664); | |
76 | ||
77 | #define VCC_DBG_DRV 0x1 | |
78 | #define VCC_DBG_LDC 0x2 | |
79 | #define VCC_DBG_PKT 0x4 | |
80 | ||
81 | #define vccdbg(f, a...) \ | |
82 | do { \ | |
83 | if (vcc_dbg & VCC_DBG_DRV) \ | |
84 | pr_info(f, ## a); \ | |
85 | } while (0) \ | |
86 | ||
87 | #define vccdbgl(l) \ | |
88 | do { \ | |
89 | if (vcc_dbg & VCC_DBG_LDC) \ | |
90 | ldc_print(l); \ | |
91 | } while (0) \ | |
92 | ||
93 | #define vccdbgp(pkt) \ | |
94 | do { \ | |
95 | if (vcc_dbg & VCC_DBG_PKT) { \ | |
96 | int i; \ | |
97 | for (i = 0; i < pkt.tag.stype; i++) \ | |
98 | pr_info("[%c]", pkt.data[i]); \ | |
99 | } \ | |
100 | } while (0) \ | |
101 | ||
ce808b74 JR |
102 | /* Note: Be careful when adding flags to this line discipline. Don't |
103 | * add anything that will cause echoing or we'll go into recursive | |
104 | * loop echoing chars back and forth with the console drivers. | |
105 | */ | |
5bd0ea91 | 106 | static const struct ktermios vcc_tty_termios = { |
ce808b74 JR |
107 | .c_iflag = IGNBRK | IGNPAR, |
108 | .c_oflag = OPOST, | |
109 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
110 | .c_cc = INIT_C_CC, | |
111 | .c_ispeed = 38400, | |
112 | .c_ospeed = 38400 | |
113 | }; | |
114 | ||
5d171050 JR |
115 | /** |
116 | * vcc_table_add() - Add VCC port to the VCC table | |
117 | * @port: pointer to the VCC port | |
118 | * | |
119 | * Return: index of the port in the VCC table on success, | |
120 | * -1 on failure | |
121 | */ | |
122 | static int vcc_table_add(struct vcc_port *port) | |
123 | { | |
124 | unsigned long flags; | |
125 | int i; | |
126 | ||
127 | spin_lock_irqsave(&vcc_table_lock, flags); | |
128 | for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) { | |
129 | if (!vcc_table[i]) { | |
130 | vcc_table[i] = port; | |
131 | break; | |
132 | } | |
133 | } | |
134 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
135 | ||
136 | if (i < VCC_MAX_PORTS) | |
137 | return i; | |
138 | else | |
139 | return -1; | |
140 | } | |
141 | ||
142 | /** | |
143 | * vcc_table_remove() - Removes a VCC port from the VCC table | |
144 | * @index: Index into the VCC table | |
145 | */ | |
146 | static void vcc_table_remove(unsigned long index) | |
147 | { | |
148 | unsigned long flags; | |
149 | ||
150 | if (WARN_ON(index >= VCC_MAX_PORTS)) | |
151 | return; | |
152 | ||
153 | spin_lock_irqsave(&vcc_table_lock, flags); | |
154 | vcc_table[index] = NULL; | |
155 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
156 | } | |
157 | ||
158 | /** | |
159 | * vcc_get() - Gets a reference to VCC port | |
160 | * @index: Index into the VCC table | |
161 | * @excl: Indicates if an exclusive access is requested | |
162 | * | |
163 | * Return: reference to the VCC port, if found | |
164 | * NULL, if port not found | |
165 | */ | |
166 | static struct vcc_port *vcc_get(unsigned long index, bool excl) | |
167 | { | |
168 | struct vcc_port *port; | |
169 | unsigned long flags; | |
170 | ||
171 | try_again: | |
172 | spin_lock_irqsave(&vcc_table_lock, flags); | |
173 | ||
174 | port = vcc_table[index]; | |
175 | if (!port) { | |
176 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
177 | return NULL; | |
178 | } | |
179 | ||
180 | if (!excl) { | |
181 | if (port->excl_locked) { | |
182 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
183 | udelay(VCC_REF_DELAY); | |
184 | goto try_again; | |
185 | } | |
186 | port->refcnt++; | |
187 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
188 | return port; | |
189 | } | |
190 | ||
191 | if (port->refcnt) { | |
192 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
193 | /* Threads wanting exclusive access will wait half the time, | |
194 | * probably giving them higher priority in the case of | |
195 | * multiple waiters. | |
196 | */ | |
197 | udelay(VCC_REF_DELAY/2); | |
198 | goto try_again; | |
199 | } | |
200 | ||
201 | port->refcnt++; | |
202 | port->excl_locked = true; | |
203 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
204 | ||
205 | return port; | |
206 | } | |
207 | ||
208 | /** | |
209 | * vcc_put() - Returns a reference to VCC port | |
210 | * @port: pointer to VCC port | |
211 | * @excl: Indicates if the returned reference is an exclusive reference | |
212 | * | |
213 | * Note: It's the caller's responsibility to ensure the correct value | |
214 | * for the excl flag | |
215 | */ | |
216 | static void vcc_put(struct vcc_port *port, bool excl) | |
217 | { | |
218 | unsigned long flags; | |
219 | ||
220 | if (!port) | |
221 | return; | |
222 | ||
223 | spin_lock_irqsave(&vcc_table_lock, flags); | |
224 | ||
225 | /* check if caller attempted to put with the wrong flags */ | |
226 | if (WARN_ON((excl && !port->excl_locked) || | |
227 | (!excl && port->excl_locked))) | |
228 | goto done; | |
229 | ||
230 | port->refcnt--; | |
231 | ||
232 | if (excl) | |
233 | port->excl_locked = false; | |
234 | ||
235 | done: | |
236 | spin_unlock_irqrestore(&vcc_table_lock, flags); | |
237 | } | |
238 | ||
239 | /** | |
240 | * vcc_get_ne() - Get a non-exclusive reference to VCC port | |
241 | * @index: Index into the VCC table | |
242 | * | |
243 | * Gets a non-exclusive reference to VCC port, if it's not removed | |
244 | * | |
245 | * Return: pointer to the VCC port, if found | |
246 | * NULL, if port not found | |
247 | */ | |
248 | static struct vcc_port *vcc_get_ne(unsigned long index) | |
249 | { | |
250 | struct vcc_port *port; | |
251 | ||
252 | port = vcc_get(index, false); | |
253 | ||
254 | if (port && port->removed) { | |
255 | vcc_put(port, false); | |
256 | return NULL; | |
257 | } | |
258 | ||
259 | return port; | |
260 | } | |
261 | ||
f8c55335 JR |
262 | static void vcc_kick_rx(struct vcc_port *port) |
263 | { | |
264 | struct vio_driver_state *vio = &port->vio; | |
265 | ||
266 | assert_spin_locked(&port->lock); | |
267 | ||
268 | if (!timer_pending(&port->rx_timer) && !port->removed) { | |
269 | disable_irq_nosync(vio->vdev->rx_irq); | |
270 | port->rx_timer.expires = (jiffies + 1); | |
271 | add_timer(&port->rx_timer); | |
272 | } | |
273 | } | |
274 | ||
275 | static void vcc_kick_tx(struct vcc_port *port) | |
276 | { | |
277 | assert_spin_locked(&port->lock); | |
278 | ||
279 | if (!timer_pending(&port->tx_timer) && !port->removed) { | |
280 | port->tx_timer.expires = (jiffies + 1); | |
281 | add_timer(&port->tx_timer); | |
282 | } | |
283 | } | |
284 | ||
285 | static int vcc_rx_check(struct tty_struct *tty, int size) | |
286 | { | |
287 | if (WARN_ON(!tty || !tty->port)) | |
288 | return 1; | |
289 | ||
290 | /* tty_buffer_request_room won't sleep because it uses | |
291 | * GFP_ATOMIC flag to allocate buffer | |
292 | */ | |
293 | if (test_bit(TTY_THROTTLED, &tty->flags) || | |
294 | (tty_buffer_request_room(tty->port, VCC_BUFF_LEN) < VCC_BUFF_LEN)) | |
295 | return 0; | |
296 | ||
297 | return 1; | |
298 | } | |
299 | ||
300 | static int vcc_rx(struct tty_struct *tty, char *buf, int size) | |
301 | { | |
302 | int len = 0; | |
303 | ||
304 | if (WARN_ON(!tty || !tty->port)) | |
305 | return len; | |
306 | ||
307 | len = tty_insert_flip_string(tty->port, buf, size); | |
308 | if (len) | |
309 | tty_flip_buffer_push(tty->port); | |
310 | ||
311 | return len; | |
312 | } | |
313 | ||
314 | static int vcc_ldc_read(struct vcc_port *port) | |
315 | { | |
316 | struct vio_driver_state *vio = &port->vio; | |
317 | struct tty_struct *tty; | |
318 | struct vio_vcc pkt; | |
319 | int rv = 0; | |
320 | ||
321 | tty = port->tty; | |
322 | if (!tty) { | |
323 | rv = ldc_rx_reset(vio->lp); | |
324 | vccdbg("VCC: reset rx q: rv=%d\n", rv); | |
325 | goto done; | |
326 | } | |
327 | ||
328 | /* Read as long as LDC has incoming data. */ | |
329 | while (1) { | |
330 | if (!vcc_rx_check(tty, VIO_VCC_MTU_SIZE)) { | |
331 | vcc_kick_rx(port); | |
332 | break; | |
333 | } | |
334 | ||
335 | vccdbgl(vio->lp); | |
336 | ||
337 | rv = ldc_read(vio->lp, &pkt, sizeof(pkt)); | |
338 | if (rv <= 0) | |
339 | break; | |
340 | ||
341 | vccdbg("VCC: ldc_read()=%d\n", rv); | |
342 | vccdbg("TAG [%02x:%02x:%04x:%08x]\n", | |
343 | pkt.tag.type, pkt.tag.stype, | |
344 | pkt.tag.stype_env, pkt.tag.sid); | |
345 | ||
346 | if (pkt.tag.type == VIO_TYPE_DATA) { | |
347 | vccdbgp(pkt); | |
348 | /* vcc_rx_check ensures memory availability */ | |
349 | vcc_rx(tty, pkt.data, pkt.tag.stype); | |
350 | } else { | |
351 | pr_err("VCC: unknown msg [%02x:%02x:%04x:%08x]\n", | |
352 | pkt.tag.type, pkt.tag.stype, | |
353 | pkt.tag.stype_env, pkt.tag.sid); | |
354 | rv = -ECONNRESET; | |
355 | break; | |
356 | } | |
357 | ||
358 | WARN_ON(rv != LDC_PACKET_SIZE); | |
359 | } | |
360 | ||
361 | done: | |
362 | return rv; | |
363 | } | |
364 | ||
4790b6dc | 365 | static void vcc_rx_timer(struct timer_list *t) |
f8c55335 | 366 | { |
4790b6dc | 367 | struct vcc_port *port = from_timer(port, t, rx_timer); |
f8c55335 | 368 | struct vio_driver_state *vio; |
f8c55335 JR |
369 | unsigned long flags; |
370 | int rv; | |
371 | ||
f8c55335 JR |
372 | spin_lock_irqsave(&port->lock, flags); |
373 | port->rx_timer.expires = 0; | |
374 | ||
375 | vio = &port->vio; | |
376 | ||
377 | enable_irq(vio->vdev->rx_irq); | |
378 | ||
379 | if (!port->tty || port->removed) | |
380 | goto done; | |
381 | ||
382 | rv = vcc_ldc_read(port); | |
383 | if (rv == -ECONNRESET) | |
384 | vio_conn_reset(vio); | |
385 | ||
386 | done: | |
387 | spin_unlock_irqrestore(&port->lock, flags); | |
388 | vcc_put(port, false); | |
389 | } | |
390 | ||
4790b6dc | 391 | static void vcc_tx_timer(struct timer_list *t) |
f8c55335 | 392 | { |
4790b6dc | 393 | struct vcc_port *port = from_timer(port, t, tx_timer); |
f8c55335 JR |
394 | struct vio_vcc *pkt; |
395 | unsigned long flags; | |
396 | int tosend = 0; | |
397 | int rv; | |
398 | ||
f8c55335 JR |
399 | spin_lock_irqsave(&port->lock, flags); |
400 | port->tx_timer.expires = 0; | |
401 | ||
402 | if (!port->tty || port->removed) | |
403 | goto done; | |
404 | ||
405 | tosend = min(VCC_BUFF_LEN, port->chars_in_buffer); | |
406 | if (!tosend) | |
407 | goto done; | |
408 | ||
409 | pkt = &port->buffer; | |
410 | pkt->tag.type = VIO_TYPE_DATA; | |
411 | pkt->tag.stype = tosend; | |
412 | vccdbgl(port->vio.lp); | |
413 | ||
414 | rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend)); | |
415 | WARN_ON(!rv); | |
416 | ||
417 | if (rv < 0) { | |
418 | vccdbg("VCC: ldc_write()=%d\n", rv); | |
419 | vcc_kick_tx(port); | |
420 | } else { | |
421 | struct tty_struct *tty = port->tty; | |
422 | ||
423 | port->chars_in_buffer = 0; | |
424 | if (tty) | |
425 | tty_wakeup(tty); | |
426 | } | |
427 | ||
428 | done: | |
429 | spin_unlock_irqrestore(&port->lock, flags); | |
430 | vcc_put(port, false); | |
431 | } | |
432 | ||
103b9b0b JR |
433 | /** |
434 | * vcc_event() - LDC event processing engine | |
435 | * @arg: VCC private data | |
436 | * @event: LDC event | |
437 | * | |
438 | * Handles LDC events for VCC | |
439 | */ | |
5d171050 JR |
440 | static void vcc_event(void *arg, int event) |
441 | { | |
103b9b0b JR |
442 | struct vio_driver_state *vio; |
443 | struct vcc_port *port; | |
444 | unsigned long flags; | |
445 | int rv; | |
446 | ||
447 | port = arg; | |
448 | vio = &port->vio; | |
449 | ||
450 | spin_lock_irqsave(&port->lock, flags); | |
451 | ||
452 | switch (event) { | |
453 | case LDC_EVENT_RESET: | |
454 | case LDC_EVENT_UP: | |
455 | vio_link_state_change(vio, event); | |
456 | break; | |
457 | ||
458 | case LDC_EVENT_DATA_READY: | |
459 | rv = vcc_ldc_read(port); | |
460 | if (rv == -ECONNRESET) | |
461 | vio_conn_reset(vio); | |
462 | break; | |
463 | ||
464 | default: | |
465 | pr_err("VCC: unexpected LDC event(%d)\n", event); | |
466 | } | |
467 | ||
468 | spin_unlock_irqrestore(&port->lock, flags); | |
5d171050 JR |
469 | } |
470 | ||
471 | static struct ldc_channel_config vcc_ldc_cfg = { | |
472 | .event = vcc_event, | |
473 | .mtu = VIO_VCC_MTU_SIZE, | |
474 | .mode = LDC_MODE_RAW, | |
475 | .debug = 0, | |
476 | }; | |
477 | ||
478 | /* Ordered from largest major to lowest */ | |
479 | static struct vio_version vcc_versions[] = { | |
480 | { .major = 1, .minor = 0 }, | |
481 | }; | |
482 | ||
8f03f948 JR |
483 | static struct tty_port_operations vcc_port_ops = { 0 }; |
484 | ||
8868e44a JR |
485 | static ssize_t vcc_sysfs_domain_show(struct device *dev, |
486 | struct device_attribute *attr, | |
487 | char *buf) | |
488 | { | |
489 | struct vcc_port *port; | |
490 | int rv; | |
491 | ||
492 | port = dev_get_drvdata(dev); | |
493 | if (!port) | |
494 | return -ENODEV; | |
495 | ||
496 | rv = scnprintf(buf, PAGE_SIZE, "%s\n", port->domain); | |
497 | ||
498 | return rv; | |
499 | } | |
500 | ||
501 | static int vcc_send_ctl(struct vcc_port *port, int ctl) | |
502 | { | |
503 | struct vio_vcc pkt; | |
504 | int rv; | |
505 | ||
506 | pkt.tag.type = VIO_TYPE_CTRL; | |
507 | pkt.tag.sid = ctl; | |
508 | pkt.tag.stype = 0; | |
509 | ||
510 | rv = ldc_write(port->vio.lp, &pkt, sizeof(pkt.tag)); | |
511 | WARN_ON(!rv); | |
512 | vccdbg("VCC: ldc_write(%ld)=%d\n", sizeof(pkt.tag), rv); | |
513 | ||
514 | return rv; | |
515 | } | |
516 | ||
517 | static ssize_t vcc_sysfs_break_store(struct device *dev, | |
518 | struct device_attribute *attr, | |
519 | const char *buf, size_t count) | |
520 | { | |
521 | struct vcc_port *port; | |
522 | unsigned long flags; | |
523 | int rv = count; | |
524 | int brk; | |
525 | ||
526 | port = dev_get_drvdata(dev); | |
527 | if (!port) | |
528 | return -ENODEV; | |
529 | ||
530 | spin_lock_irqsave(&port->lock, flags); | |
531 | ||
532 | if (sscanf(buf, "%ud", &brk) != 1 || brk != 1) | |
533 | rv = -EINVAL; | |
534 | else if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0) | |
f8c55335 | 535 | vcc_kick_tx(port); |
8868e44a JR |
536 | |
537 | spin_unlock_irqrestore(&port->lock, flags); | |
538 | ||
539 | return rv; | |
540 | } | |
541 | ||
542 | static DEVICE_ATTR(domain, 0400, vcc_sysfs_domain_show, NULL); | |
543 | static DEVICE_ATTR(break, 0200, NULL, vcc_sysfs_break_store); | |
544 | ||
545 | static struct attribute *vcc_sysfs_entries[] = { | |
546 | &dev_attr_domain.attr, | |
547 | &dev_attr_break.attr, | |
548 | NULL | |
549 | }; | |
550 | ||
551 | static struct attribute_group vcc_attribute_group = { | |
552 | .name = NULL, | |
553 | .attrs = vcc_sysfs_entries, | |
554 | }; | |
555 | ||
5d171050 JR |
556 | /** |
557 | * vcc_probe() - Initialize VCC port | |
558 | * @vdev: Pointer to VIO device of the new VCC port | |
559 | * @id: VIO device ID | |
560 | * | |
561 | * Initializes a VCC port to receive serial console data from | |
562 | * the guest domain. Sets up a TTY end point on the control | |
563 | * domain. Sets up VIO/LDC link between the guest & control | |
564 | * domain endpoints. | |
565 | * | |
566 | * Return: status of the probe | |
567 | */ | |
568 | static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id) | |
569 | { | |
570 | struct mdesc_handle *hp; | |
571 | struct vcc_port *port; | |
572 | struct device *dev; | |
573 | const char *domain; | |
574 | char *name; | |
575 | u64 node; | |
576 | int rv; | |
577 | ||
578 | vccdbg("VCC: name=%s\n", dev_name(&vdev->dev)); | |
579 | ||
580 | if (!vcc_tty_driver) { | |
581 | pr_err("VCC: TTY driver not registered\n"); | |
582 | return -ENODEV; | |
583 | } | |
584 | ||
585 | port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL); | |
586 | if (!port) | |
587 | return -ENOMEM; | |
588 | ||
589 | name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL); | |
590 | ||
591 | rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions, | |
592 | ARRAY_SIZE(vcc_versions), NULL, name); | |
593 | if (rv) | |
594 | goto free_port; | |
595 | ||
596 | port->vio.debug = vcc_dbg_vio; | |
597 | vcc_ldc_cfg.debug = vcc_dbg_ldc; | |
598 | ||
599 | rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port); | |
600 | if (rv) | |
601 | goto free_port; | |
602 | ||
603 | spin_lock_init(&port->lock); | |
604 | ||
605 | port->index = vcc_table_add(port); | |
606 | if (port->index == -1) { | |
607 | pr_err("VCC: no more TTY indices left for allocation\n"); | |
ff62255a | 608 | rv = -ENOMEM; |
5d171050 JR |
609 | goto free_ldc; |
610 | } | |
611 | ||
612 | /* Register the device using VCC table index as TTY index */ | |
613 | dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev); | |
614 | if (IS_ERR(dev)) { | |
615 | rv = PTR_ERR(dev); | |
616 | goto free_table; | |
617 | } | |
618 | ||
619 | hp = mdesc_grab(); | |
620 | ||
621 | node = vio_vdev_node(hp, vdev); | |
622 | if (node == MDESC_NODE_NULL) { | |
623 | rv = -ENXIO; | |
624 | mdesc_release(hp); | |
625 | goto unreg_tty; | |
626 | } | |
627 | ||
628 | domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL); | |
629 | if (!domain) { | |
630 | rv = -ENXIO; | |
631 | mdesc_release(hp); | |
632 | goto unreg_tty; | |
633 | } | |
634 | port->domain = kstrdup(domain, GFP_KERNEL); | |
635 | ||
636 | mdesc_release(hp); | |
637 | ||
8868e44a JR |
638 | rv = sysfs_create_group(&vdev->dev.kobj, &vcc_attribute_group); |
639 | if (rv) | |
640 | goto free_domain; | |
641 | ||
4790b6dc KC |
642 | timer_setup(&port->rx_timer, vcc_rx_timer, 0); |
643 | timer_setup(&port->tx_timer, vcc_tx_timer, 0); | |
f8c55335 | 644 | |
5d171050 JR |
645 | dev_set_drvdata(&vdev->dev, port); |
646 | ||
647 | /* It's possible to receive IRQs in the middle of vio_port_up. Disable | |
648 | * IRQs until the port is up. | |
649 | */ | |
650 | disable_irq_nosync(vdev->rx_irq); | |
651 | vio_port_up(&port->vio); | |
652 | enable_irq(vdev->rx_irq); | |
653 | ||
654 | return 0; | |
655 | ||
8868e44a JR |
656 | free_domain: |
657 | kfree(port->domain); | |
5d171050 JR |
658 | unreg_tty: |
659 | tty_unregister_device(vcc_tty_driver, port->index); | |
660 | free_table: | |
661 | vcc_table_remove(port->index); | |
662 | free_ldc: | |
663 | vio_ldc_free(&port->vio); | |
664 | free_port: | |
665 | kfree(name); | |
666 | kfree(port); | |
667 | ||
668 | return rv; | |
669 | } | |
670 | ||
671 | /** | |
672 | * vcc_remove() - Terminate a VCC port | |
673 | * @vdev: Pointer to VIO device of the VCC port | |
674 | * | |
675 | * Terminates a VCC port. Sets up the teardown of TTY and | |
676 | * VIO/LDC link between guest and primary domains. | |
677 | * | |
678 | * Return: status of removal | |
679 | */ | |
680 | static int vcc_remove(struct vio_dev *vdev) | |
681 | { | |
682 | struct vcc_port *port = dev_get_drvdata(&vdev->dev); | |
683 | ||
684 | if (!port) | |
685 | return -ENODEV; | |
686 | ||
f8c55335 JR |
687 | del_timer_sync(&port->rx_timer); |
688 | del_timer_sync(&port->tx_timer); | |
689 | ||
5d171050 JR |
690 | /* If there's a process with the device open, do a synchronous |
691 | * hangup of the TTY. This *may* cause the process to call close | |
692 | * asynchronously, but it's not guaranteed. | |
693 | */ | |
694 | if (port->tty) | |
695 | tty_vhangup(port->tty); | |
696 | ||
697 | /* Get exclusive reference to VCC, ensures that there are no other | |
698 | * clients to this port | |
699 | */ | |
700 | port = vcc_get(port->index, true); | |
701 | ||
702 | if (WARN_ON(!port)) | |
703 | return -ENODEV; | |
704 | ||
705 | tty_unregister_device(vcc_tty_driver, port->index); | |
706 | ||
707 | del_timer_sync(&port->vio.timer); | |
708 | vio_ldc_free(&port->vio); | |
8868e44a | 709 | sysfs_remove_group(&vdev->dev.kobj, &vcc_attribute_group); |
5d171050 | 710 | dev_set_drvdata(&vdev->dev, NULL); |
5d171050 JR |
711 | if (port->tty) { |
712 | port->removed = true; | |
713 | vcc_put(port, true); | |
714 | } else { | |
715 | vcc_table_remove(port->index); | |
716 | ||
717 | kfree(port->vio.name); | |
718 | kfree(port->domain); | |
719 | kfree(port); | |
720 | } | |
721 | ||
722 | return 0; | |
723 | } | |
724 | ||
725 | static const struct vio_device_id vcc_match[] = { | |
726 | { | |
727 | .type = "vcc-port", | |
728 | }, | |
729 | {}, | |
730 | }; | |
731 | MODULE_DEVICE_TABLE(vio, vcc_match); | |
732 | ||
733 | static struct vio_driver vcc_driver = { | |
734 | .id_table = vcc_match, | |
735 | .probe = vcc_probe, | |
736 | .remove = vcc_remove, | |
737 | .name = "vcc", | |
738 | }; | |
739 | ||
63a71744 JR |
740 | static int vcc_open(struct tty_struct *tty, struct file *vcc_file) |
741 | { | |
742 | struct vcc_port *port; | |
743 | ||
744 | if (unlikely(!tty)) { | |
745 | pr_err("VCC: open: Invalid TTY handle\n"); | |
746 | return -ENXIO; | |
747 | } | |
748 | ||
749 | if (tty->count > 1) | |
750 | return -EBUSY; | |
751 | ||
752 | port = vcc_get_ne(tty->index); | |
753 | if (unlikely(!port)) { | |
754 | pr_err("VCC: open: Failed to find VCC port\n"); | |
755 | return -ENODEV; | |
756 | } | |
757 | ||
758 | if (unlikely(!port->vio.lp)) { | |
759 | pr_err("VCC: open: LDC channel not configured\n"); | |
760 | vcc_put(port, false); | |
761 | return -EPIPE; | |
762 | } | |
763 | vccdbgl(port->vio.lp); | |
764 | ||
765 | vcc_put(port, false); | |
766 | ||
767 | if (unlikely(!tty->port)) { | |
768 | pr_err("VCC: open: TTY port not found\n"); | |
769 | return -ENXIO; | |
770 | } | |
771 | ||
772 | if (unlikely(!tty->port->ops)) { | |
773 | pr_err("VCC: open: TTY ops not defined\n"); | |
774 | return -ENXIO; | |
775 | } | |
776 | ||
777 | return tty_port_open(tty->port, tty, vcc_file); | |
778 | } | |
779 | ||
780 | static void vcc_close(struct tty_struct *tty, struct file *vcc_file) | |
781 | { | |
782 | if (unlikely(!tty)) { | |
783 | pr_err("VCC: close: Invalid TTY handle\n"); | |
784 | return; | |
785 | } | |
786 | ||
787 | if (unlikely(tty->count > 1)) | |
788 | return; | |
789 | ||
790 | if (unlikely(!tty->port)) { | |
791 | pr_err("VCC: close: TTY port not found\n"); | |
792 | return; | |
793 | } | |
794 | ||
795 | tty_port_close(tty->port, tty, vcc_file); | |
796 | } | |
797 | ||
6a3ff25b JR |
798 | static void vcc_ldc_hup(struct vcc_port *port) |
799 | { | |
800 | unsigned long flags; | |
801 | ||
802 | spin_lock_irqsave(&port->lock, flags); | |
803 | ||
804 | if (vcc_send_ctl(port, VCC_CTL_HUP) < 0) | |
805 | vcc_kick_tx(port); | |
806 | ||
807 | spin_unlock_irqrestore(&port->lock, flags); | |
808 | } | |
809 | ||
810 | static void vcc_hangup(struct tty_struct *tty) | |
811 | { | |
812 | struct vcc_port *port; | |
813 | ||
814 | if (unlikely(!tty)) { | |
815 | pr_err("VCC: hangup: Invalid TTY handle\n"); | |
816 | return; | |
817 | } | |
818 | ||
819 | port = vcc_get_ne(tty->index); | |
820 | if (unlikely(!port)) { | |
821 | pr_err("VCC: hangup: Failed to find VCC port\n"); | |
822 | return; | |
823 | } | |
824 | ||
825 | if (unlikely(!tty->port)) { | |
826 | pr_err("VCC: hangup: TTY port not found\n"); | |
827 | vcc_put(port, false); | |
828 | return; | |
829 | } | |
830 | ||
831 | vcc_ldc_hup(port); | |
832 | ||
833 | vcc_put(port, false); | |
834 | ||
835 | tty_port_hangup(tty->port); | |
836 | } | |
837 | ||
cf045260 JR |
838 | static int vcc_write(struct tty_struct *tty, const unsigned char *buf, |
839 | int count) | |
840 | { | |
841 | struct vcc_port *port; | |
842 | struct vio_vcc *pkt; | |
843 | unsigned long flags; | |
844 | int total_sent = 0; | |
845 | int tosend = 0; | |
846 | int rv = -EINVAL; | |
847 | ||
848 | if (unlikely(!tty)) { | |
849 | pr_err("VCC: write: Invalid TTY handle\n"); | |
850 | return -ENXIO; | |
851 | } | |
852 | ||
853 | port = vcc_get_ne(tty->index); | |
854 | if (unlikely(!port)) { | |
855 | pr_err("VCC: write: Failed to find VCC port"); | |
856 | return -ENODEV; | |
857 | } | |
858 | ||
859 | spin_lock_irqsave(&port->lock, flags); | |
860 | ||
861 | pkt = &port->buffer; | |
862 | pkt->tag.type = VIO_TYPE_DATA; | |
863 | ||
864 | while (count > 0) { | |
865 | /* Minimum of data to write and space available */ | |
866 | tosend = min(count, (VCC_BUFF_LEN - port->chars_in_buffer)); | |
867 | ||
868 | if (!tosend) | |
869 | break; | |
870 | ||
871 | memcpy(&pkt->data[port->chars_in_buffer], &buf[total_sent], | |
872 | tosend); | |
873 | port->chars_in_buffer += tosend; | |
874 | pkt->tag.stype = tosend; | |
875 | ||
876 | vccdbg("TAG [%02x:%02x:%04x:%08x]\n", pkt->tag.type, | |
877 | pkt->tag.stype, pkt->tag.stype_env, pkt->tag.sid); | |
878 | vccdbg("DATA [%s]\n", pkt->data); | |
879 | vccdbgl(port->vio.lp); | |
880 | ||
881 | /* Since we know we have enough room in VCC buffer for tosend | |
882 | * we record that it was sent regardless of whether the | |
883 | * hypervisor actually took it because we have it buffered. | |
884 | */ | |
885 | rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend)); | |
886 | vccdbg("VCC: write: ldc_write(%d)=%d\n", | |
887 | (VIO_TAG_SIZE + tosend), rv); | |
888 | ||
889 | total_sent += tosend; | |
890 | count -= tosend; | |
891 | if (rv < 0) { | |
892 | vcc_kick_tx(port); | |
893 | break; | |
894 | } | |
895 | ||
896 | port->chars_in_buffer = 0; | |
897 | } | |
898 | ||
899 | spin_unlock_irqrestore(&port->lock, flags); | |
900 | ||
901 | vcc_put(port, false); | |
902 | ||
903 | vccdbg("VCC: write: total=%d rv=%d", total_sent, rv); | |
904 | ||
905 | return total_sent ? total_sent : rv; | |
906 | } | |
907 | ||
908 | static int vcc_write_room(struct tty_struct *tty) | |
909 | { | |
910 | struct vcc_port *port; | |
911 | u64 num; | |
912 | ||
913 | if (unlikely(!tty)) { | |
914 | pr_err("VCC: write_room: Invalid TTY handle\n"); | |
915 | return -ENXIO; | |
916 | } | |
917 | ||
918 | port = vcc_get_ne(tty->index); | |
919 | if (unlikely(!port)) { | |
920 | pr_err("VCC: write_room: Failed to find VCC port\n"); | |
921 | return -ENODEV; | |
922 | } | |
923 | ||
924 | num = VCC_BUFF_LEN - port->chars_in_buffer; | |
925 | ||
926 | vcc_put(port, false); | |
927 | ||
928 | return num; | |
929 | } | |
930 | ||
aeee7deb JR |
931 | static int vcc_chars_in_buffer(struct tty_struct *tty) |
932 | { | |
933 | struct vcc_port *port; | |
934 | u64 num; | |
935 | ||
936 | if (unlikely(!tty)) { | |
937 | pr_err("VCC: chars_in_buffer: Invalid TTY handle\n"); | |
938 | return -ENXIO; | |
939 | } | |
940 | ||
941 | port = vcc_get_ne(tty->index); | |
942 | if (unlikely(!port)) { | |
943 | pr_err("VCC: chars_in_buffer: Failed to find VCC port\n"); | |
944 | return -ENODEV; | |
945 | } | |
946 | ||
947 | num = port->chars_in_buffer; | |
948 | ||
949 | vcc_put(port, false); | |
950 | ||
951 | return num; | |
952 | } | |
953 | ||
e942e577 JR |
954 | static int vcc_break_ctl(struct tty_struct *tty, int state) |
955 | { | |
956 | struct vcc_port *port; | |
957 | unsigned long flags; | |
958 | ||
959 | if (unlikely(!tty)) { | |
960 | pr_err("VCC: break_ctl: Invalid TTY handle\n"); | |
961 | return -ENXIO; | |
962 | } | |
963 | ||
964 | port = vcc_get_ne(tty->index); | |
965 | if (unlikely(!port)) { | |
966 | pr_err("VCC: break_ctl: Failed to find VCC port\n"); | |
967 | return -ENODEV; | |
968 | } | |
969 | ||
970 | /* Turn off break */ | |
971 | if (state == 0) { | |
972 | vcc_put(port, false); | |
973 | return 0; | |
974 | } | |
975 | ||
976 | spin_lock_irqsave(&port->lock, flags); | |
977 | ||
978 | if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0) | |
979 | vcc_kick_tx(port); | |
980 | ||
981 | spin_unlock_irqrestore(&port->lock, flags); | |
982 | ||
983 | vcc_put(port, false); | |
984 | ||
985 | return 0; | |
986 | } | |
987 | ||
8f03f948 JR |
988 | static int vcc_install(struct tty_driver *driver, struct tty_struct *tty) |
989 | { | |
990 | struct vcc_port *port_vcc; | |
991 | struct tty_port *port_tty; | |
992 | int ret; | |
993 | ||
994 | if (unlikely(!tty)) { | |
995 | pr_err("VCC: install: Invalid TTY handle\n"); | |
996 | return -ENXIO; | |
997 | } | |
998 | ||
999 | if (tty->index >= VCC_MAX_PORTS) | |
1000 | return -EINVAL; | |
1001 | ||
1002 | ret = tty_standard_install(driver, tty); | |
1003 | if (ret) | |
1004 | return ret; | |
1005 | ||
1006 | port_tty = kzalloc(sizeof(struct tty_port), GFP_KERNEL); | |
1007 | if (!port_tty) | |
1008 | return -ENOMEM; | |
1009 | ||
1010 | port_vcc = vcc_get(tty->index, true); | |
1011 | if (!port_vcc) { | |
1012 | pr_err("VCC: install: Failed to find VCC port\n"); | |
1013 | tty->port = NULL; | |
1014 | kfree(port_tty); | |
1015 | return -ENODEV; | |
1016 | } | |
1017 | ||
1018 | tty_port_init(port_tty); | |
1019 | port_tty->ops = &vcc_port_ops; | |
1020 | tty->port = port_tty; | |
1021 | ||
1022 | port_vcc->tty = tty; | |
1023 | ||
1024 | vcc_put(port_vcc, true); | |
1025 | ||
1026 | return 0; | |
1027 | } | |
1028 | ||
1029 | static void vcc_cleanup(struct tty_struct *tty) | |
1030 | { | |
1031 | struct vcc_port *port; | |
1032 | ||
1033 | if (unlikely(!tty)) { | |
1034 | pr_err("VCC: cleanup: Invalid TTY handle\n"); | |
1035 | return; | |
1036 | } | |
1037 | ||
1038 | port = vcc_get(tty->index, true); | |
1039 | if (port) { | |
1040 | port->tty = NULL; | |
1041 | ||
1042 | if (port->removed) { | |
1043 | vcc_table_remove(tty->index); | |
1044 | kfree(port->vio.name); | |
1045 | kfree(port->domain); | |
1046 | kfree(port); | |
1047 | } else { | |
1048 | vcc_put(port, true); | |
1049 | } | |
1050 | } | |
1051 | ||
1052 | tty_port_destroy(tty->port); | |
1053 | kfree(tty->port); | |
1054 | tty->port = NULL; | |
1055 | } | |
1056 | ||
63a71744 | 1057 | static const struct tty_operations vcc_ops = { |
aeee7deb JR |
1058 | .open = vcc_open, |
1059 | .close = vcc_close, | |
1060 | .hangup = vcc_hangup, | |
1061 | .write = vcc_write, | |
1062 | .write_room = vcc_write_room, | |
1063 | .chars_in_buffer = vcc_chars_in_buffer, | |
e942e577 | 1064 | .break_ctl = vcc_break_ctl, |
8f03f948 JR |
1065 | .install = vcc_install, |
1066 | .cleanup = vcc_cleanup, | |
63a71744 | 1067 | }; |
ce808b74 JR |
1068 | |
1069 | #define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW) | |
1070 | ||
1071 | static int vcc_tty_init(void) | |
55bd2133 | 1072 | { |
ce808b74 JR |
1073 | int rv; |
1074 | ||
1075 | pr_info("VCC: %s\n", version); | |
1076 | ||
1077 | vcc_tty_driver = tty_alloc_driver(VCC_MAX_PORTS, VCC_TTY_FLAGS); | |
c6b4ee9e | 1078 | if (IS_ERR(vcc_tty_driver)) { |
ce808b74 | 1079 | pr_err("VCC: TTY driver alloc failed\n"); |
c6b4ee9e | 1080 | return PTR_ERR(vcc_tty_driver); |
ce808b74 JR |
1081 | } |
1082 | ||
1083 | vcc_tty_driver->driver_name = vcc_driver_name; | |
1084 | vcc_tty_driver->name = vcc_device_node; | |
1085 | ||
1086 | vcc_tty_driver->minor_start = VCC_MINOR_START; | |
1087 | vcc_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
1088 | vcc_tty_driver->init_termios = vcc_tty_termios; | |
1089 | ||
1090 | tty_set_operations(vcc_tty_driver, &vcc_ops); | |
1091 | ||
1092 | rv = tty_register_driver(vcc_tty_driver); | |
1093 | if (rv) { | |
1094 | pr_err("VCC: TTY driver registration failed\n"); | |
1095 | put_tty_driver(vcc_tty_driver); | |
1096 | vcc_tty_driver = NULL; | |
1097 | return rv; | |
1098 | } | |
1099 | ||
1100 | vccdbg("VCC: TTY driver registered\n"); | |
1101 | ||
55bd2133 JR |
1102 | return 0; |
1103 | } | |
1104 | ||
ce808b74 JR |
1105 | static void vcc_tty_exit(void) |
1106 | { | |
1107 | tty_unregister_driver(vcc_tty_driver); | |
1108 | put_tty_driver(vcc_tty_driver); | |
1109 | vccdbg("VCC: TTY driver unregistered\n"); | |
1110 | ||
1111 | vcc_tty_driver = NULL; | |
1112 | } | |
1113 | ||
1114 | static int __init vcc_init(void) | |
1115 | { | |
1116 | int rv; | |
1117 | ||
1118 | rv = vcc_tty_init(); | |
1119 | if (rv) { | |
1120 | pr_err("VCC: TTY init failed\n"); | |
1121 | return rv; | |
1122 | } | |
1123 | ||
5d171050 JR |
1124 | rv = vio_register_driver(&vcc_driver); |
1125 | if (rv) { | |
1126 | pr_err("VCC: VIO driver registration failed\n"); | |
1127 | vcc_tty_exit(); | |
1128 | } else { | |
1129 | vccdbg("VCC: VIO driver registered successfully\n"); | |
1130 | } | |
1131 | ||
ce808b74 JR |
1132 | return rv; |
1133 | } | |
1134 | ||
55bd2133 JR |
1135 | static void __exit vcc_exit(void) |
1136 | { | |
5d171050 JR |
1137 | vio_unregister_driver(&vcc_driver); |
1138 | vccdbg("VCC: VIO driver unregistered\n"); | |
ce808b74 JR |
1139 | vcc_tty_exit(); |
1140 | vccdbg("VCC: TTY driver unregistered\n"); | |
55bd2133 JR |
1141 | } |
1142 | ||
1143 | module_init(vcc_init); | |
1144 | module_exit(vcc_exit); |