1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* vcc.c: sun4v virtual channel concentrator |
3 | * |
4 | * Copyright (C) 2017 Oracle. All rights reserved. |
5 | */ |
6 | |
7 | #include <linux/delay.h> |
8 | #include <linux/interrupt.h> |
9 | #include <linux/module.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/sysfs.h> |
12 | #include <linux/tty.h> |
13 | #include <linux/tty_flip.h> |
14 | #include <linux/termios_internal.h> |
15 | #include <asm/vio.h> |
16 | #include <asm/ldc.h> |
17 | |
18 | MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver" ); |
19 | MODULE_LICENSE("GPL" ); |
20 | MODULE_VERSION("1.1" ); |
21 | |
22 | struct vcc_port { |
23 | struct vio_driver_state vio; |
24 | |
25 | spinlock_t lock; |
26 | char *domain; |
27 | struct tty_struct *tty; /* only populated while dev is open */ |
28 | unsigned long index; /* index into the vcc_table */ |
29 | |
30 | u64 refcnt; |
31 | bool excl_locked; |
32 | |
33 | bool removed; |
34 | |
35 | /* This buffer is required to support the tty write_room interface |
36 | * and guarantee that any characters that the driver accepts will |
37 | * be eventually sent, either immediately or later. |
38 | */ |
39 | size_t chars_in_buffer; |
40 | struct vio_vcc buffer; |
41 | |
42 | struct timer_list rx_timer; |
43 | struct timer_list tx_timer; |
44 | }; |
45 | |
46 | /* Microseconds that thread will delay waiting for a vcc port ref */ |
47 | #define VCC_REF_DELAY 100 |
48 | |
49 | #define VCC_MAX_PORTS 1024 |
50 | #define VCC_MINOR_START 0 /* must be zero */ |
51 | #define VCC_BUFF_LEN VIO_VCC_MTU_SIZE |
52 | |
53 | #define VCC_CTL_BREAK -1 |
54 | #define VCC_CTL_HUP -2 |
55 | |
56 | static struct tty_driver *vcc_tty_driver; |
57 | |
58 | static struct vcc_port *vcc_table[VCC_MAX_PORTS]; |
59 | static DEFINE_SPINLOCK(vcc_table_lock); |
60 | |
61 | static unsigned int vcc_dbg; |
62 | static unsigned int vcc_dbg_ldc; |
63 | static unsigned int vcc_dbg_vio; |
64 | |
65 | module_param(vcc_dbg, uint, 0664); |
66 | module_param(vcc_dbg_ldc, uint, 0664); |
67 | module_param(vcc_dbg_vio, uint, 0664); |
68 | |
69 | #define VCC_DBG_DRV 0x1 |
70 | #define VCC_DBG_LDC 0x2 |
71 | #define VCC_DBG_PKT 0x4 |
72 | |
73 | #define vccdbg(f, a...) \ |
74 | do { \ |
75 | if (vcc_dbg & VCC_DBG_DRV) \ |
76 | pr_info(f, ## a); \ |
77 | } while (0) \ |
78 | |
79 | #define vccdbgl(l) \ |
80 | do { \ |
81 | if (vcc_dbg & VCC_DBG_LDC) \ |
82 | ldc_print(l); \ |
83 | } while (0) \ |
84 | |
85 | #define vccdbgp(pkt) \ |
86 | do { \ |
87 | if (vcc_dbg & VCC_DBG_PKT) { \ |
88 | int i; \ |
89 | for (i = 0; i < pkt.tag.stype; i++) \ |
90 | pr_info("[%c]", pkt.data[i]); \ |
91 | } \ |
92 | } while (0) \ |
93 | |
94 | /* Note: Be careful when adding flags to this line discipline. Don't |
95 | * add anything that will cause echoing or we'll go into recursive |
96 | * loop echoing chars back and forth with the console drivers. |
97 | */ |
98 | static const struct ktermios vcc_tty_termios = { |
99 | .c_iflag = IGNBRK | IGNPAR, |
100 | .c_oflag = OPOST, |
101 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, |
102 | .c_cc = INIT_C_CC, |
103 | .c_ispeed = 38400, |
104 | .c_ospeed = 38400 |
105 | }; |
106 | |
107 | /** |
108 | * vcc_table_add() - Add VCC port to the VCC table |
109 | * @port: pointer to the VCC port |
110 | * |
111 | * Return: index of the port in the VCC table on success, |
112 | * -1 on failure |
113 | */ |
114 | static int vcc_table_add(struct vcc_port *port) |
115 | { |
116 | unsigned long flags; |
117 | int i; |
118 | |
119 | spin_lock_irqsave(&vcc_table_lock, flags); |
120 | for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) { |
121 | if (!vcc_table[i]) { |
122 | vcc_table[i] = port; |
123 | break; |
124 | } |
125 | } |
126 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
127 | |
128 | if (i < VCC_MAX_PORTS) |
129 | return i; |
130 | else |
131 | return -1; |
132 | } |
133 | |
134 | /** |
135 | * vcc_table_remove() - Removes a VCC port from the VCC table |
136 | * @index: Index into the VCC table |
137 | */ |
138 | static void vcc_table_remove(unsigned long index) |
139 | { |
140 | unsigned long flags; |
141 | |
142 | if (WARN_ON(index >= VCC_MAX_PORTS)) |
143 | return; |
144 | |
145 | spin_lock_irqsave(&vcc_table_lock, flags); |
146 | vcc_table[index] = NULL; |
147 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
148 | } |
149 | |
150 | /** |
151 | * vcc_get() - Gets a reference to VCC port |
152 | * @index: Index into the VCC table |
153 | * @excl: Indicates if an exclusive access is requested |
154 | * |
155 | * Return: reference to the VCC port, if found |
156 | * NULL, if port not found |
157 | */ |
158 | static struct vcc_port *vcc_get(unsigned long index, bool excl) |
159 | { |
160 | struct vcc_port *port; |
161 | unsigned long flags; |
162 | |
163 | try_again: |
164 | spin_lock_irqsave(&vcc_table_lock, flags); |
165 | |
166 | port = vcc_table[index]; |
167 | if (!port) { |
168 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
169 | return NULL; |
170 | } |
171 | |
172 | if (!excl) { |
173 | if (port->excl_locked) { |
174 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
175 | udelay(VCC_REF_DELAY); |
176 | goto try_again; |
177 | } |
178 | port->refcnt++; |
179 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
180 | return port; |
181 | } |
182 | |
183 | if (port->refcnt) { |
184 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
185 | /* Threads wanting exclusive access will wait half the time, |
186 | * probably giving them higher priority in the case of |
187 | * multiple waiters. |
188 | */ |
189 | udelay(VCC_REF_DELAY/2); |
190 | goto try_again; |
191 | } |
192 | |
193 | port->refcnt++; |
194 | port->excl_locked = true; |
195 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
196 | |
197 | return port; |
198 | } |
199 | |
200 | /** |
201 | * vcc_put() - Returns a reference to VCC port |
202 | * @port: pointer to VCC port |
203 | * @excl: Indicates if the returned reference is an exclusive reference |
204 | * |
205 | * Note: It's the caller's responsibility to ensure the correct value |
206 | * for the excl flag |
207 | */ |
208 | static void vcc_put(struct vcc_port *port, bool excl) |
209 | { |
210 | unsigned long flags; |
211 | |
212 | if (!port) |
213 | return; |
214 | |
215 | spin_lock_irqsave(&vcc_table_lock, flags); |
216 | |
217 | /* check if caller attempted to put with the wrong flags */ |
218 | if (WARN_ON((excl && !port->excl_locked) || |
219 | (!excl && port->excl_locked))) |
220 | goto done; |
221 | |
222 | port->refcnt--; |
223 | |
224 | if (excl) |
225 | port->excl_locked = false; |
226 | |
227 | done: |
228 | spin_unlock_irqrestore(&vcc_table_lock, flags); |
229 | } |
230 | |
231 | /** |
232 | * vcc_get_ne() - Get a non-exclusive reference to VCC port |
233 | * @index: Index into the VCC table |
234 | * |
235 | * Gets a non-exclusive reference to VCC port, if it's not removed |
236 | * |
237 | * Return: pointer to the VCC port, if found |
238 | * NULL, if port not found |
239 | */ |
240 | static struct vcc_port *vcc_get_ne(unsigned long index) |
241 | { |
242 | struct vcc_port *port; |
243 | |
244 | port = vcc_get(index, false); |
245 | |
246 | if (port && port->removed) { |
247 | vcc_put(port, false); |
248 | return NULL; |
249 | } |
250 | |
251 | return port; |
252 | } |
253 | |
254 | static void vcc_kick_rx(struct vcc_port *port) |
255 | { |
256 | struct vio_driver_state *vio = &port->vio; |
257 | |
258 | assert_spin_locked(&port->lock); |
259 | |
260 | if (!timer_pending(&port->rx_timer) && !port->removed) { |
261 | disable_irq_nosync(vio->vdev->rx_irq); |
262 | port->rx_timer.expires = (jiffies + 1); |
263 | add_timer(&port->rx_timer); |
264 | } |
265 | } |
266 | |
267 | static void vcc_kick_tx(struct vcc_port *port) |
268 | { |
269 | assert_spin_locked(&port->lock); |
270 | |
271 | if (!timer_pending(&port->tx_timer) && !port->removed) { |
272 | port->tx_timer.expires = (jiffies + 1); |
273 | add_timer(&port->tx_timer); |
274 | } |
275 | } |
276 | |
277 | static int vcc_rx_check(struct tty_struct *tty, int size) |
278 | { |
279 | if (WARN_ON(!tty || !tty->port)) |
280 | return 1; |
281 | |
282 | /* tty_buffer_request_room won't sleep because it uses |
283 | * GFP_ATOMIC flag to allocate buffer |
284 | */ |
285 | if (test_bit(TTY_THROTTLED, &tty->flags) || |
286 | (tty_buffer_request_room(tty->port, VCC_BUFF_LEN) < VCC_BUFF_LEN)) |
287 | return 0; |
288 | |
289 | return 1; |
290 | } |
291 | |
292 | static int vcc_rx(struct tty_struct *tty, char *buf, int size) |
293 | { |
294 | int len = 0; |
295 | |
296 | if (WARN_ON(!tty || !tty->port)) |
297 | return len; |
298 | |
299 | len = tty_insert_flip_string(tty->port, buf, size); |
300 | if (len) |
301 | tty_flip_buffer_push(tty->port); |
302 | |
303 | return len; |
304 | } |
305 | |
306 | static int vcc_ldc_read(struct vcc_port *port) |
307 | { |
308 | struct vio_driver_state *vio = &port->vio; |
309 | struct tty_struct *tty; |
310 | struct vio_vcc pkt; |
311 | int rv = 0; |
312 | |
313 | tty = port->tty; |
314 | if (!tty) { |
315 | rv = ldc_rx_reset(vio->lp); |
316 | vccdbg("VCC: reset rx q: rv=%d\n" , rv); |
317 | goto done; |
318 | } |
319 | |
320 | /* Read as long as LDC has incoming data. */ |
321 | while (1) { |
322 | if (!vcc_rx_check(tty, VIO_VCC_MTU_SIZE)) { |
323 | vcc_kick_rx(port); |
324 | break; |
325 | } |
326 | |
327 | vccdbgl(vio->lp); |
328 | |
329 | rv = ldc_read(vio->lp, &pkt, sizeof(pkt)); |
330 | if (rv <= 0) |
331 | break; |
332 | |
333 | vccdbg("VCC: ldc_read()=%d\n" , rv); |
334 | vccdbg("TAG [%02x:%02x:%04x:%08x]\n" , |
335 | pkt.tag.type, pkt.tag.stype, |
336 | pkt.tag.stype_env, pkt.tag.sid); |
337 | |
338 | if (pkt.tag.type == VIO_TYPE_DATA) { |
339 | vccdbgp(pkt); |
340 | /* vcc_rx_check ensures memory availability */ |
341 | vcc_rx(tty, buf: pkt.data, size: pkt.tag.stype); |
342 | } else { |
343 | pr_err("VCC: unknown msg [%02x:%02x:%04x:%08x]\n" , |
344 | pkt.tag.type, pkt.tag.stype, |
345 | pkt.tag.stype_env, pkt.tag.sid); |
346 | rv = -ECONNRESET; |
347 | break; |
348 | } |
349 | |
350 | WARN_ON(rv != LDC_PACKET_SIZE); |
351 | } |
352 | |
353 | done: |
354 | return rv; |
355 | } |
356 | |
357 | static void vcc_rx_timer(struct timer_list *t) |
358 | { |
359 | struct vcc_port *port = from_timer(port, t, rx_timer); |
360 | struct vio_driver_state *vio; |
361 | unsigned long flags; |
362 | int rv; |
363 | |
364 | spin_lock_irqsave(&port->lock, flags); |
365 | port->rx_timer.expires = 0; |
366 | |
367 | vio = &port->vio; |
368 | |
369 | enable_irq(vio->vdev->rx_irq); |
370 | |
371 | if (!port->tty || port->removed) |
372 | goto done; |
373 | |
374 | rv = vcc_ldc_read(port); |
375 | if (rv == -ECONNRESET) |
376 | vio_conn_reset(vio); |
377 | |
378 | done: |
379 | spin_unlock_irqrestore(&port->lock, flags); |
380 | vcc_put(port, false); |
381 | } |
382 | |
383 | static void vcc_tx_timer(struct timer_list *t) |
384 | { |
385 | struct vcc_port *port = from_timer(port, t, tx_timer); |
386 | struct vio_vcc *pkt; |
387 | unsigned long flags; |
388 | size_t tosend = 0; |
389 | int rv; |
390 | |
391 | spin_lock_irqsave(&port->lock, flags); |
392 | port->tx_timer.expires = 0; |
393 | |
394 | if (!port->tty || port->removed) |
395 | goto done; |
396 | |
397 | tosend = min(VCC_BUFF_LEN, port->chars_in_buffer); |
398 | if (!tosend) |
399 | goto done; |
400 | |
401 | pkt = &port->buffer; |
402 | pkt->tag.type = VIO_TYPE_DATA; |
403 | pkt->tag.stype = tosend; |
404 | vccdbgl(port->vio.lp); |
405 | |
406 | rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend)); |
407 | WARN_ON(!rv); |
408 | |
409 | if (rv < 0) { |
410 | vccdbg("VCC: ldc_write()=%d\n" , rv); |
411 | vcc_kick_tx(port); |
412 | } else { |
413 | struct tty_struct *tty = port->tty; |
414 | |
415 | port->chars_in_buffer = 0; |
416 | if (tty) |
417 | tty_wakeup(tty); |
418 | } |
419 | |
420 | done: |
421 | spin_unlock_irqrestore(&port->lock, flags); |
422 | vcc_put(port, false); |
423 | } |
424 | |
425 | /** |
426 | * vcc_event() - LDC event processing engine |
427 | * @arg: VCC private data |
428 | * @event: LDC event |
429 | * |
430 | * Handles LDC events for VCC |
431 | */ |
432 | static void vcc_event(void *arg, int event) |
433 | { |
434 | struct vio_driver_state *vio; |
435 | struct vcc_port *port; |
436 | unsigned long flags; |
437 | int rv; |
438 | |
439 | port = arg; |
440 | vio = &port->vio; |
441 | |
442 | spin_lock_irqsave(&port->lock, flags); |
443 | |
444 | switch (event) { |
445 | case LDC_EVENT_RESET: |
446 | case LDC_EVENT_UP: |
447 | vio_link_state_change(vio, event); |
448 | break; |
449 | |
450 | case LDC_EVENT_DATA_READY: |
451 | rv = vcc_ldc_read(port); |
452 | if (rv == -ECONNRESET) |
453 | vio_conn_reset(vio); |
454 | break; |
455 | |
456 | default: |
457 | pr_err("VCC: unexpected LDC event(%d)\n" , event); |
458 | } |
459 | |
460 | spin_unlock_irqrestore(&port->lock, flags); |
461 | } |
462 | |
463 | static struct ldc_channel_config vcc_ldc_cfg = { |
464 | .event = vcc_event, |
465 | .mtu = VIO_VCC_MTU_SIZE, |
466 | .mode = LDC_MODE_RAW, |
467 | .debug = 0, |
468 | }; |
469 | |
470 | /* Ordered from largest major to lowest */ |
471 | static struct vio_version vcc_versions[] = { |
472 | { .major = 1, .minor = 0 }, |
473 | }; |
474 | |
475 | static struct tty_port_operations vcc_port_ops = { 0 }; |
476 | |
477 | static ssize_t domain_show(struct device *dev, |
478 | struct device_attribute *attr, |
479 | char *buf) |
480 | { |
481 | struct vcc_port *port; |
482 | int rv; |
483 | |
484 | port = dev_get_drvdata(dev); |
485 | if (!port) |
486 | return -ENODEV; |
487 | |
488 | rv = scnprintf(buf, PAGE_SIZE, "%s\n" , port->domain); |
489 | |
490 | return rv; |
491 | } |
492 | |
493 | static int vcc_send_ctl(struct vcc_port *port, int ctl) |
494 | { |
495 | struct vio_vcc pkt; |
496 | int rv; |
497 | |
498 | pkt.tag.type = VIO_TYPE_CTRL; |
499 | pkt.tag.sid = ctl; |
500 | pkt.tag.stype = 0; |
501 | |
502 | rv = ldc_write(port->vio.lp, &pkt, sizeof(pkt.tag)); |
503 | WARN_ON(!rv); |
504 | vccdbg("VCC: ldc_write(%ld)=%d\n" , sizeof(pkt.tag), rv); |
505 | |
506 | return rv; |
507 | } |
508 | |
509 | static ssize_t break_store(struct device *dev, |
510 | struct device_attribute *attr, |
511 | const char *buf, size_t count) |
512 | { |
513 | struct vcc_port *port; |
514 | unsigned long flags; |
515 | int rv = count; |
516 | int brk; |
517 | |
518 | port = dev_get_drvdata(dev); |
519 | if (!port) |
520 | return -ENODEV; |
521 | |
522 | spin_lock_irqsave(&port->lock, flags); |
523 | |
524 | if (sscanf(buf, "%ud" , &brk) != 1 || brk != 1) |
525 | rv = -EINVAL; |
526 | else if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0) |
527 | vcc_kick_tx(port); |
528 | |
529 | spin_unlock_irqrestore(&port->lock, flags); |
530 | |
531 | return rv; |
532 | } |
533 | |
534 | static DEVICE_ATTR_ADMIN_RO(domain); |
535 | static DEVICE_ATTR_WO(break); |
536 | |
537 | static struct attribute *vcc_sysfs_entries[] = { |
538 | &dev_attr_domain.attr, |
539 | &dev_attr_break.attr, |
540 | NULL |
541 | }; |
542 | |
543 | static struct attribute_group vcc_attribute_group = { |
544 | .name = NULL, |
545 | .attrs = vcc_sysfs_entries, |
546 | }; |
547 | |
548 | /** |
549 | * vcc_probe() - Initialize VCC port |
550 | * @vdev: Pointer to VIO device of the new VCC port |
551 | * @id: VIO device ID |
552 | * |
553 | * Initializes a VCC port to receive serial console data from |
554 | * the guest domain. Sets up a TTY end point on the control |
555 | * domain. Sets up VIO/LDC link between the guest & control |
556 | * domain endpoints. |
557 | * |
558 | * Return: status of the probe |
559 | */ |
560 | static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id) |
561 | { |
562 | struct mdesc_handle *hp; |
563 | struct vcc_port *port; |
564 | struct device *dev; |
565 | const char *domain; |
566 | char *name; |
567 | u64 node; |
568 | int rv; |
569 | |
570 | vccdbg("VCC: name=%s\n" , dev_name(&vdev->dev)); |
571 | |
572 | if (!vcc_tty_driver) { |
573 | pr_err("VCC: TTY driver not registered\n" ); |
574 | return -ENODEV; |
575 | } |
576 | |
577 | port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL); |
578 | if (!port) |
579 | return -ENOMEM; |
580 | |
581 | name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL); |
582 | if (!name) { |
583 | rv = -ENOMEM; |
584 | goto free_port; |
585 | } |
586 | |
587 | rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions, |
588 | ARRAY_SIZE(vcc_versions), NULL, name); |
589 | if (rv) |
590 | goto free_name; |
591 | |
592 | port->vio.debug = vcc_dbg_vio; |
593 | vcc_ldc_cfg.debug = vcc_dbg_ldc; |
594 | |
595 | rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port); |
596 | if (rv) |
597 | goto free_name; |
598 | |
599 | spin_lock_init(&port->lock); |
600 | |
601 | port->index = vcc_table_add(port); |
602 | if (port->index == -1) { |
603 | pr_err("VCC: no more TTY indices left for allocation\n" ); |
604 | rv = -ENOMEM; |
605 | goto free_ldc; |
606 | } |
607 | |
608 | /* Register the device using VCC table index as TTY index */ |
609 | dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev); |
610 | if (IS_ERR(dev)) { |
611 | rv = PTR_ERR(dev); |
612 | goto free_table; |
613 | } |
614 | |
615 | hp = mdesc_grab(); |
616 | |
617 | node = vio_vdev_node(hp, vdev); |
618 | if (node == MDESC_NODE_NULL) { |
619 | rv = -ENXIO; |
620 | mdesc_release(hp); |
621 | goto unreg_tty; |
622 | } |
623 | |
624 | domain = mdesc_get_property(hp, node, "vcc-domain-name" , NULL); |
625 | if (!domain) { |
626 | rv = -ENXIO; |
627 | mdesc_release(hp); |
628 | goto unreg_tty; |
629 | } |
630 | port->domain = kstrdup(domain, GFP_KERNEL); |
631 | if (!port->domain) { |
632 | rv = -ENOMEM; |
633 | goto unreg_tty; |
634 | } |
635 | |
636 | |
637 | mdesc_release(hp); |
638 | |
639 | rv = sysfs_create_group(&vdev->dev.kobj, &vcc_attribute_group); |
640 | if (rv) |
641 | goto free_domain; |
642 | |
643 | timer_setup(&port->rx_timer, vcc_rx_timer, 0); |
644 | timer_setup(&port->tx_timer, vcc_tx_timer, 0); |
645 | |
646 | dev_set_drvdata(&vdev->dev, port); |
647 | |
648 | /* It's possible to receive IRQs in the middle of vio_port_up. Disable |
649 | * IRQs until the port is up. |
650 | */ |
651 | disable_irq_nosync(vdev->rx_irq); |
652 | vio_port_up(&port->vio); |
653 | enable_irq(vdev->rx_irq); |
654 | |
655 | return 0; |
656 | |
657 | free_domain: |
658 | kfree(port->domain); |
659 | unreg_tty: |
660 | tty_unregister_device(vcc_tty_driver, port->index); |
661 | free_table: |
662 | vcc_table_remove(index: port->index); |
663 | free_ldc: |
664 | vio_ldc_free(&port->vio); |
665 | free_name: |
666 | kfree(name); |
667 | free_port: |
668 | kfree(port); |
669 | |
670 | return rv; |
671 | } |
672 | |
673 | /** |
674 | * vcc_remove() - Terminate a VCC port |
675 | * @vdev: Pointer to VIO device of the VCC port |
676 | * |
677 | * Terminates a VCC port. Sets up the teardown of TTY and |
678 | * VIO/LDC link between guest and primary domains. |
679 | * |
680 | * Return: status of removal |
681 | */ |
682 | static void vcc_remove(struct vio_dev *vdev) |
683 | { |
684 | struct vcc_port *port = dev_get_drvdata(&vdev->dev); |
685 | |
686 | del_timer_sync(&port->rx_timer); |
687 | del_timer_sync(&port->tx_timer); |
688 | |
689 | /* If there's a process with the device open, do a synchronous |
690 | * hangup of the TTY. This *may* cause the process to call close |
691 | * asynchronously, but it's not guaranteed. |
692 | */ |
693 | if (port->tty) |
694 | tty_vhangup(port->tty); |
695 | |
696 | /* Get exclusive reference to VCC, ensures that there are no other |
697 | * clients to this port. This cannot fail. |
698 | */ |
699 | vcc_get(port->index, true); |
700 | |
701 | tty_unregister_device(vcc_tty_driver, port->index); |
702 | |
703 | del_timer_sync(&port->vio.timer); |
704 | vio_ldc_free(&port->vio); |
705 | sysfs_remove_group(&vdev->dev.kobj, &vcc_attribute_group); |
706 | dev_set_drvdata(&vdev->dev, NULL); |
707 | if (port->tty) { |
708 | port->removed = true; |
709 | vcc_put(port, true); |
710 | } else { |
711 | vcc_table_remove(index: port->index); |
712 | |
713 | kfree(port->vio.name); |
714 | kfree(port->domain); |
715 | kfree(port); |
716 | } |
717 | } |
718 | |
719 | static const struct vio_device_id vcc_match[] = { |
720 | { |
721 | .type = "vcc-port" , |
722 | }, |
723 | {}, |
724 | }; |
725 | MODULE_DEVICE_TABLE(vio, vcc_match); |
726 | |
727 | static struct vio_driver vcc_driver = { |
728 | .id_table = vcc_match, |
729 | .probe = vcc_probe, |
730 | .remove = vcc_remove, |
731 | .name = "vcc" , |
732 | }; |
733 | |
734 | static int vcc_open(struct tty_struct *tty, struct file *vcc_file) |
735 | { |
736 | struct vcc_port *port; |
737 | |
738 | if (tty->count > 1) |
739 | return -EBUSY; |
740 | |
741 | port = vcc_get_ne(index: tty->index); |
742 | if (unlikely(!port)) { |
743 | pr_err("VCC: open: Failed to find VCC port\n" ); |
744 | return -ENODEV; |
745 | } |
746 | |
747 | if (unlikely(!port->vio.lp)) { |
748 | pr_err("VCC: open: LDC channel not configured\n" ); |
749 | vcc_put(port, false); |
750 | return -EPIPE; |
751 | } |
752 | vccdbgl(port->vio.lp); |
753 | |
754 | vcc_put(port, false); |
755 | |
756 | if (unlikely(!tty->port)) { |
757 | pr_err("VCC: open: TTY port not found\n" ); |
758 | return -ENXIO; |
759 | } |
760 | |
761 | if (unlikely(!tty->port->ops)) { |
762 | pr_err("VCC: open: TTY ops not defined\n" ); |
763 | return -ENXIO; |
764 | } |
765 | |
766 | return tty_port_open(tty->port, tty, vcc_file); |
767 | } |
768 | |
769 | static void vcc_close(struct tty_struct *tty, struct file *vcc_file) |
770 | { |
771 | if (unlikely(tty->count > 1)) |
772 | return; |
773 | |
774 | if (unlikely(!tty->port)) { |
775 | pr_err("VCC: close: TTY port not found\n" ); |
776 | return; |
777 | } |
778 | |
779 | tty_port_close(tty->port, tty, vcc_file); |
780 | } |
781 | |
782 | static void vcc_ldc_hup(struct vcc_port *port) |
783 | { |
784 | unsigned long flags; |
785 | |
786 | spin_lock_irqsave(&port->lock, flags); |
787 | |
788 | if (vcc_send_ctl(port, VCC_CTL_HUP) < 0) |
789 | vcc_kick_tx(port); |
790 | |
791 | spin_unlock_irqrestore(&port->lock, flags); |
792 | } |
793 | |
794 | static void vcc_hangup(struct tty_struct *tty) |
795 | { |
796 | struct vcc_port *port; |
797 | |
798 | port = vcc_get_ne(index: tty->index); |
799 | if (unlikely(!port)) { |
800 | pr_err("VCC: hangup: Failed to find VCC port\n" ); |
801 | return; |
802 | } |
803 | |
804 | if (unlikely(!tty->port)) { |
805 | pr_err("VCC: hangup: TTY port not found\n" ); |
806 | vcc_put(port, false); |
807 | return; |
808 | } |
809 | |
810 | vcc_ldc_hup(port); |
811 | |
812 | vcc_put(port, false); |
813 | |
814 | tty_port_hangup(tty->port); |
815 | } |
816 | |
817 | static ssize_t vcc_write(struct tty_struct *tty, const u8 *buf, size_t count) |
818 | { |
819 | struct vcc_port *port; |
820 | struct vio_vcc *pkt; |
821 | unsigned long flags; |
822 | size_t total_sent = 0; |
823 | size_t tosend = 0; |
824 | int rv = -EINVAL; |
825 | |
826 | port = vcc_get_ne(index: tty->index); |
827 | if (unlikely(!port)) { |
828 | pr_err("VCC: write: Failed to find VCC port" ); |
829 | return -ENODEV; |
830 | } |
831 | |
832 | spin_lock_irqsave(&port->lock, flags); |
833 | |
834 | pkt = &port->buffer; |
835 | pkt->tag.type = VIO_TYPE_DATA; |
836 | |
837 | while (count > 0) { |
838 | /* Minimum of data to write and space available */ |
839 | tosend = min_t(size_t, count, |
840 | (VCC_BUFF_LEN - port->chars_in_buffer)); |
841 | |
842 | if (!tosend) |
843 | break; |
844 | |
845 | memcpy(&pkt->data[port->chars_in_buffer], &buf[total_sent], |
846 | tosend); |
847 | port->chars_in_buffer += tosend; |
848 | pkt->tag.stype = tosend; |
849 | |
850 | vccdbg("TAG [%02x:%02x:%04x:%08x]\n" , pkt->tag.type, |
851 | pkt->tag.stype, pkt->tag.stype_env, pkt->tag.sid); |
852 | vccdbg("DATA [%s]\n" , pkt->data); |
853 | vccdbgl(port->vio.lp); |
854 | |
855 | /* Since we know we have enough room in VCC buffer for tosend |
856 | * we record that it was sent regardless of whether the |
857 | * hypervisor actually took it because we have it buffered. |
858 | */ |
859 | rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend)); |
860 | vccdbg("VCC: write: ldc_write(%zu)=%d\n" , |
861 | (VIO_TAG_SIZE + tosend), rv); |
862 | |
863 | total_sent += tosend; |
864 | count -= tosend; |
865 | if (rv < 0) { |
866 | vcc_kick_tx(port); |
867 | break; |
868 | } |
869 | |
870 | port->chars_in_buffer = 0; |
871 | } |
872 | |
873 | spin_unlock_irqrestore(&port->lock, flags); |
874 | |
875 | vcc_put(port, false); |
876 | |
877 | vccdbg("VCC: write: total=%zu rv=%d" , total_sent, rv); |
878 | |
879 | return total_sent ? total_sent : rv; |
880 | } |
881 | |
882 | static unsigned int vcc_write_room(struct tty_struct *tty) |
883 | { |
884 | struct vcc_port *port; |
885 | unsigned int num; |
886 | |
887 | port = vcc_get_ne(index: tty->index); |
888 | if (unlikely(!port)) { |
889 | pr_err("VCC: write_room: Failed to find VCC port\n" ); |
890 | return 0; |
891 | } |
892 | |
893 | num = VCC_BUFF_LEN - port->chars_in_buffer; |
894 | |
895 | vcc_put(port, false); |
896 | |
897 | return num; |
898 | } |
899 | |
900 | static unsigned int vcc_chars_in_buffer(struct tty_struct *tty) |
901 | { |
902 | struct vcc_port *port; |
903 | unsigned int num; |
904 | |
905 | port = vcc_get_ne(index: tty->index); |
906 | if (unlikely(!port)) { |
907 | pr_err("VCC: chars_in_buffer: Failed to find VCC port\n" ); |
908 | return 0; |
909 | } |
910 | |
911 | num = port->chars_in_buffer; |
912 | |
913 | vcc_put(port, false); |
914 | |
915 | return num; |
916 | } |
917 | |
918 | static int vcc_break_ctl(struct tty_struct *tty, int state) |
919 | { |
920 | struct vcc_port *port; |
921 | unsigned long flags; |
922 | |
923 | port = vcc_get_ne(index: tty->index); |
924 | if (unlikely(!port)) { |
925 | pr_err("VCC: break_ctl: Failed to find VCC port\n" ); |
926 | return -ENODEV; |
927 | } |
928 | |
929 | /* Turn off break */ |
930 | if (state == 0) { |
931 | vcc_put(port, false); |
932 | return 0; |
933 | } |
934 | |
935 | spin_lock_irqsave(&port->lock, flags); |
936 | |
937 | if (vcc_send_ctl(port, VCC_CTL_BREAK) < 0) |
938 | vcc_kick_tx(port); |
939 | |
940 | spin_unlock_irqrestore(&port->lock, flags); |
941 | |
942 | vcc_put(port, false); |
943 | |
944 | return 0; |
945 | } |
946 | |
947 | static int vcc_install(struct tty_driver *driver, struct tty_struct *tty) |
948 | { |
949 | struct vcc_port *port_vcc; |
950 | struct tty_port *port_tty; |
951 | int ret; |
952 | |
953 | if (tty->index >= VCC_MAX_PORTS) |
954 | return -EINVAL; |
955 | |
956 | ret = tty_standard_install(driver, tty); |
957 | if (ret) |
958 | return ret; |
959 | |
960 | port_tty = kzalloc(sizeof(struct tty_port), GFP_KERNEL); |
961 | if (!port_tty) |
962 | return -ENOMEM; |
963 | |
964 | port_vcc = vcc_get(tty->index, true); |
965 | if (!port_vcc) { |
966 | pr_err("VCC: install: Failed to find VCC port\n" ); |
967 | tty->port = NULL; |
968 | kfree(port_tty); |
969 | return -ENODEV; |
970 | } |
971 | |
972 | tty_port_init(port_tty); |
973 | port_tty->ops = &vcc_port_ops; |
974 | tty->port = port_tty; |
975 | |
976 | port_vcc->tty = tty; |
977 | |
978 | vcc_put(port_vcc, true); |
979 | |
980 | return 0; |
981 | } |
982 | |
983 | static void vcc_cleanup(struct tty_struct *tty) |
984 | { |
985 | struct vcc_port *port; |
986 | |
987 | port = vcc_get(tty->index, true); |
988 | if (port) { |
989 | port->tty = NULL; |
990 | |
991 | if (port->removed) { |
992 | vcc_table_remove(index: tty->index); |
993 | kfree(port->vio.name); |
994 | kfree(port->domain); |
995 | kfree(port); |
996 | } else { |
997 | vcc_put(port, true); |
998 | } |
999 | } |
1000 | |
1001 | tty_port_destroy(tty->port); |
1002 | kfree(tty->port); |
1003 | tty->port = NULL; |
1004 | } |
1005 | |
1006 | static const struct tty_operations vcc_ops = { |
1007 | .open = vcc_open, |
1008 | .close = vcc_close, |
1009 | .hangup = vcc_hangup, |
1010 | .write = vcc_write, |
1011 | .write_room = vcc_write_room, |
1012 | .chars_in_buffer = vcc_chars_in_buffer, |
1013 | .break_ctl = vcc_break_ctl, |
1014 | .install = vcc_install, |
1015 | .cleanup = vcc_cleanup, |
1016 | }; |
1017 | |
1018 | #define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW) |
1019 | |
1020 | static int vcc_tty_init(void) |
1021 | { |
1022 | int rv; |
1023 | |
1024 | vcc_tty_driver = tty_alloc_driver(VCC_MAX_PORTS, VCC_TTY_FLAGS); |
1025 | if (IS_ERR(vcc_tty_driver)) { |
1026 | pr_err("VCC: TTY driver alloc failed\n" ); |
1027 | return PTR_ERR(vcc_tty_driver); |
1028 | } |
1029 | |
1030 | vcc_tty_driver->driver_name = "vcc" ; |
1031 | vcc_tty_driver->name = "vcc" ; |
1032 | |
1033 | vcc_tty_driver->minor_start = VCC_MINOR_START; |
1034 | vcc_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; |
1035 | vcc_tty_driver->init_termios = vcc_tty_termios; |
1036 | |
1037 | tty_set_operations(vcc_tty_driver, &vcc_ops); |
1038 | |
1039 | rv = tty_register_driver(vcc_tty_driver); |
1040 | if (rv) { |
1041 | pr_err("VCC: TTY driver registration failed\n" ); |
1042 | tty_driver_kref_put(vcc_tty_driver); |
1043 | vcc_tty_driver = NULL; |
1044 | return rv; |
1045 | } |
1046 | |
1047 | vccdbg("VCC: TTY driver registered\n" ); |
1048 | |
1049 | return 0; |
1050 | } |
1051 | |
1052 | static void vcc_tty_exit(void) |
1053 | { |
1054 | tty_unregister_driver(vcc_tty_driver); |
1055 | tty_driver_kref_put(vcc_tty_driver); |
1056 | vccdbg("VCC: TTY driver unregistered\n" ); |
1057 | |
1058 | vcc_tty_driver = NULL; |
1059 | } |
1060 | |
1061 | static int __init vcc_init(void) |
1062 | { |
1063 | int rv; |
1064 | |
1065 | rv = vcc_tty_init(); |
1066 | if (rv) { |
1067 | pr_err("VCC: TTY init failed\n" ); |
1068 | return rv; |
1069 | } |
1070 | |
1071 | rv = vio_register_driver(&vcc_driver); |
1072 | if (rv) { |
1073 | pr_err("VCC: VIO driver registration failed\n" ); |
1074 | vcc_tty_exit(); |
1075 | } else { |
1076 | vccdbg("VCC: VIO driver registered successfully\n" ); |
1077 | } |
1078 | |
1079 | return rv; |
1080 | } |
1081 | |
1082 | static void __exit vcc_exit(void) |
1083 | { |
1084 | vio_unregister_driver(&vcc_driver); |
1085 | vccdbg("VCC: VIO driver unregistered\n" ); |
1086 | vcc_tty_exit(); |
1087 | vccdbg("VCC: TTY driver unregistered\n" ); |
1088 | } |
1089 | |
1090 | module_init(vcc_init); |
1091 | module_exit(vcc_exit); |
1092 | |