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staging: erofs: integrate decompression inplace
[linux/fpc-iii.git] / drivers / tty / serial / sunhv.c
blob63e34d868de8f32973b163267b0f45777bdfaaf2
1 // SPDX-License-Identifier: GPL-2.0
2 /* sunhv.c: Serial driver for SUN4V hypervisor console.
3 *
4 * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
5 */
6
7 #include <linux/kernel.h>
8 #include <linux/errno.h>
9 #include <linux/tty.h>
10 #include <linux/tty_flip.h>
11 #include <linux/major.h>
12 #include <linux/circ_buf.h>
13 #include <linux/serial.h>
14 #include <linux/sysrq.h>
15 #include <linux/console.h>
16 #include <linux/spinlock.h>
17 #include <linux/slab.h>
18 #include <linux/delay.h>
19 #include <linux/init.h>
20 #include <linux/of_device.h>
21
22 #include <asm/hypervisor.h>
23 #include <asm/spitfire.h>
24 #include <asm/prom.h>
25 #include <asm/irq.h>
26 #include <asm/setup.h>
27
28 #if defined(CONFIG_MAGIC_SYSRQ)
29 #define SUPPORT_SYSRQ
30 #endif
31
32 #include <linux/serial_core.h>
33 #include <linux/sunserialcore.h>
34
35 #define CON_BREAK ((long)-1)
36 #define CON_HUP ((long)-2)
37
38 #define IGNORE_BREAK 0x1
39 #define IGNORE_ALL 0x2
40
41 static char *con_write_page;
42 static char *con_read_page;
43
44 static int hung_up = 0;
45
46 static void transmit_chars_putchar(struct uart_port *port, struct circ_buf *xmit)
47 {
48 while (!uart_circ_empty(xmit)) {
49 long status = sun4v_con_putchar(xmit->buf[xmit->tail]);
50
51 if (status != HV_EOK)
52 break;
53
54 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
55 port->icount.tx++;
56 }
57 }
58
59 static void transmit_chars_write(struct uart_port *port, struct circ_buf *xmit)
60 {
61 while (!uart_circ_empty(xmit)) {
62 unsigned long ra = __pa(xmit->buf + xmit->tail);
63 unsigned long len, status, sent;
64
65 len = CIRC_CNT_TO_END(xmit->head, xmit->tail,
66 UART_XMIT_SIZE);
67 status = sun4v_con_write(ra, len, &sent);
68 if (status != HV_EOK)
69 break;
70 xmit->tail = (xmit->tail + sent) & (UART_XMIT_SIZE - 1);
71 port->icount.tx += sent;
72 }
73 }
74
75 static int receive_chars_getchar(struct uart_port *port)
76 {
77 int saw_console_brk = 0;
78 int limit = 10000;
79
80 while (limit-- > 0) {
81 long status;
82 long c = sun4v_con_getchar(&status);
83
84 if (status == HV_EWOULDBLOCK)
85 break;
86
87 if (c == CON_BREAK) {
88 if (uart_handle_break(port))
89 continue;
90 saw_console_brk = 1;
91 c = 0;
92 }
93
94 if (c == CON_HUP) {
95 hung_up = 1;
96 uart_handle_dcd_change(port, 0);
97 } else if (hung_up) {
98 hung_up = 0;
99 uart_handle_dcd_change(port, 1);
100 }
101
102 if (port->state == NULL) {
103 uart_handle_sysrq_char(port, c);
104 continue;
105 }
106
107 port->icount.rx++;
108
109 if (uart_handle_sysrq_char(port, c))
110 continue;
111
112 tty_insert_flip_char(&port->state->port, c, TTY_NORMAL);
113 }
114
115 return saw_console_brk;
116 }
117
118 static int receive_chars_read(struct uart_port *port)
119 {
120 static int saw_console_brk;
121 int limit = 10000;
122
123 while (limit-- > 0) {
124 unsigned long ra = __pa(con_read_page);
125 unsigned long bytes_read, i;
126 long stat = sun4v_con_read(ra, PAGE_SIZE, &bytes_read);
127
128 if (stat != HV_EOK) {
129 bytes_read = 0;
130
131 if (stat == CON_BREAK) {
132 if (saw_console_brk)
133 sun_do_break();
134
135 if (uart_handle_break(port))
136 continue;
137 saw_console_brk = 1;
138 *con_read_page = 0;
139 bytes_read = 1;
140 } else if (stat == CON_HUP) {
141 hung_up = 1;
142 uart_handle_dcd_change(port, 0);
143 continue;
144 } else {
145 /* HV_EWOULDBLOCK, etc. */
146 break;
147 }
148 }
149
150 if (hung_up) {
151 hung_up = 0;
152 uart_handle_dcd_change(port, 1);
153 }
154
155 if (port->sysrq != 0 && *con_read_page) {
156 for (i = 0; i < bytes_read; i++)
157 uart_handle_sysrq_char(port, con_read_page[i]);
158 saw_console_brk = 0;
159 }
160
161 if (port->state == NULL)
162 continue;
163
164 port->icount.rx += bytes_read;
165
166 tty_insert_flip_string(&port->state->port, con_read_page,
167 bytes_read);
168 }
169
170 return saw_console_brk;
171 }
172
173 struct sunhv_ops {
174 void (*transmit_chars)(struct uart_port *port, struct circ_buf *xmit);
175 int (*receive_chars)(struct uart_port *port);
176 };
177
178 static const struct sunhv_ops bychar_ops = {
179 .transmit_chars = transmit_chars_putchar,
180 .receive_chars = receive_chars_getchar,
181 };
182
183 static const struct sunhv_ops bywrite_ops = {
184 .transmit_chars = transmit_chars_write,
185 .receive_chars = receive_chars_read,
186 };
187
188 static const struct sunhv_ops *sunhv_ops = &bychar_ops;
189
190 static struct tty_port *receive_chars(struct uart_port *port)
191 {
192 struct tty_port *tport = NULL;
193
194 if (port->state != NULL) /* Unopened serial console */
195 tport = &port->state->port;
196
197 if (sunhv_ops->receive_chars(port))
198 sun_do_break();
199
200 return tport;
201 }
202
203 static void transmit_chars(struct uart_port *port)
204 {
205 struct circ_buf *xmit;
206
207 if (!port->state)
208 return;
209
210 xmit = &port->state->xmit;
211 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
212 return;
213
214 sunhv_ops->transmit_chars(port, xmit);
215
216 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
217 uart_write_wakeup(port);
218 }
219
220 static irqreturn_t sunhv_interrupt(int irq, void *dev_id)
221 {
222 struct uart_port *port = dev_id;
223 struct tty_port *tport;
224 unsigned long flags;
225
226 spin_lock_irqsave(&port->lock, flags);
227 tport = receive_chars(port);
228 transmit_chars(port);
229 spin_unlock_irqrestore(&port->lock, flags);
230
231 if (tport)
232 tty_flip_buffer_push(tport);
233
234 return IRQ_HANDLED;
235 }
236
237 /* port->lock is not held. */
238 static unsigned int sunhv_tx_empty(struct uart_port *port)
239 {
240 /* Transmitter is always empty for us. If the circ buffer
241 * is non-empty or there is an x_char pending, our caller
242 * will do the right thing and ignore what we return here.
243 */
244 return TIOCSER_TEMT;
245 }
246
247 /* port->lock held by caller. */
248 static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl)
249 {
250 return;
251 }
252
253 /* port->lock is held by caller and interrupts are disabled. */
254 static unsigned int sunhv_get_mctrl(struct uart_port *port)
255 {
256 return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS;
257 }
258
259 /* port->lock held by caller. */
260 static void sunhv_stop_tx(struct uart_port *port)
261 {
262 return;
263 }
264
265 /* port->lock held by caller. */
266 static void sunhv_start_tx(struct uart_port *port)
267 {
268 transmit_chars(port);
269 }
270
271 /* port->lock is not held. */
272 static void sunhv_send_xchar(struct uart_port *port, char ch)
273 {
274 unsigned long flags;
275 int limit = 10000;
276
277 if (ch == __DISABLED_CHAR)
278 return;
279
280 spin_lock_irqsave(&port->lock, flags);
281
282 while (limit-- > 0) {
283 long status = sun4v_con_putchar(ch);
284 if (status == HV_EOK)
285 break;
286 udelay(1);
287 }
288
289 spin_unlock_irqrestore(&port->lock, flags);
290 }
291
292 /* port->lock held by caller. */
293 static void sunhv_stop_rx(struct uart_port *port)
294 {
295 }
296
297 /* port->lock is not held. */
298 static void sunhv_break_ctl(struct uart_port *port, int break_state)
299 {
300 if (break_state) {
301 unsigned long flags;
302 int limit = 10000;
303
304 spin_lock_irqsave(&port->lock, flags);
305
306 while (limit-- > 0) {
307 long status = sun4v_con_putchar(CON_BREAK);
308 if (status == HV_EOK)
309 break;
310 udelay(1);
311 }
312
313 spin_unlock_irqrestore(&port->lock, flags);
314 }
315 }
316
317 /* port->lock is not held. */
318 static int sunhv_startup(struct uart_port *port)
319 {
320 return 0;
321 }
322
323 /* port->lock is not held. */
324 static void sunhv_shutdown(struct uart_port *port)
325 {
326 }
327
328 /* port->lock is not held. */
329 static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios,
330 struct ktermios *old)
331 {
332 unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
333 unsigned int quot = uart_get_divisor(port, baud);
334 unsigned int iflag, cflag;
335 unsigned long flags;
336
337 spin_lock_irqsave(&port->lock, flags);
338
339 iflag = termios->c_iflag;
340 cflag = termios->c_cflag;
341
342 port->ignore_status_mask = 0;
343 if (iflag & IGNBRK)
344 port->ignore_status_mask |= IGNORE_BREAK;
345 if ((cflag & CREAD) == 0)
346 port->ignore_status_mask |= IGNORE_ALL;
347
348 /* XXX */
349 uart_update_timeout(port, cflag,
350 (port->uartclk / (16 * quot)));
351
352 spin_unlock_irqrestore(&port->lock, flags);
353 }
354
355 static const char *sunhv_type(struct uart_port *port)
356 {
357 return "SUN4V HCONS";
358 }
359
360 static void sunhv_release_port(struct uart_port *port)
361 {
362 }
363
364 static int sunhv_request_port(struct uart_port *port)
365 {
366 return 0;
367 }
368
369 static void sunhv_config_port(struct uart_port *port, int flags)
370 {
371 }
372
373 static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser)
374 {
375 return -EINVAL;
376 }
377
378 static const struct uart_ops sunhv_pops = {
379 .tx_empty = sunhv_tx_empty,
380 .set_mctrl = sunhv_set_mctrl,
381 .get_mctrl = sunhv_get_mctrl,
382 .stop_tx = sunhv_stop_tx,
383 .start_tx = sunhv_start_tx,
384 .send_xchar = sunhv_send_xchar,
385 .stop_rx = sunhv_stop_rx,
386 .break_ctl = sunhv_break_ctl,
387 .startup = sunhv_startup,
388 .shutdown = sunhv_shutdown,
389 .set_termios = sunhv_set_termios,
390 .type = sunhv_type,
391 .release_port = sunhv_release_port,
392 .request_port = sunhv_request_port,
393 .config_port = sunhv_config_port,
394 .verify_port = sunhv_verify_port,
395 };
396
397 static struct uart_driver sunhv_reg = {
398 .owner = THIS_MODULE,
399 .driver_name = "sunhv",
400 .dev_name = "ttyS",
401 .major = TTY_MAJOR,
402 };
403
404 static struct uart_port *sunhv_port;
405
406 void sunhv_migrate_hvcons_irq(int cpu)
407 {
408 /* Migrate hvcons irq to param cpu */
409 irq_force_affinity(sunhv_port->irq, cpumask_of(cpu));
410 }
411
412 /* Copy 's' into the con_write_page, decoding "\n" into
413 * "\r\n" along the way. We have to return two lengths
414 * because the caller needs to know how much to advance
415 * 's' and also how many bytes to output via con_write_page.
416 */
417 static int fill_con_write_page(const char *s, unsigned int n,
418 unsigned long *page_bytes)
419 {
420 const char *orig_s = s;
421 char *p = con_write_page;
422 int left = PAGE_SIZE;
423
424 while (n--) {
425 if (*s == '\n') {
426 if (left < 2)
427 break;
428 *p++ = '\r';
429 left--;
430 } else if (left < 1)
431 break;
432 *p++ = *s++;
433 left--;
434 }
435 *page_bytes = p - con_write_page;
436 return s - orig_s;
437 }
438
439 static void sunhv_console_write_paged(struct console *con, const char *s, unsigned n)
440 {
441 struct uart_port *port = sunhv_port;
442 unsigned long flags;
443 int locked = 1;
444
445 if (port->sysrq || oops_in_progress)
446 locked = spin_trylock_irqsave(&port->lock, flags);
447 else
448 spin_lock_irqsave(&port->lock, flags);
449
450 while (n > 0) {
451 unsigned long ra = __pa(con_write_page);
452 unsigned long page_bytes;
453 unsigned int cpy = fill_con_write_page(s, n,
454 &page_bytes);
455
456 n -= cpy;
457 s += cpy;
458 while (page_bytes > 0) {
459 unsigned long written;
460 int limit = 1000000;
461
462 while (limit--) {
463 unsigned long stat;
464
465 stat = sun4v_con_write(ra, page_bytes,
466 &written);
467 if (stat == HV_EOK)
468 break;
469 udelay(1);
470 }
471 if (limit < 0)
472 break;
473 page_bytes -= written;
474 ra += written;
475 }
476 }
477
478 if (locked)
479 spin_unlock_irqrestore(&port->lock, flags);
480 }
481
482 static inline void sunhv_console_putchar(struct uart_port *port, char c)
483 {
484 int limit = 1000000;
485
486 while (limit-- > 0) {
487 long status = sun4v_con_putchar(c);
488 if (status == HV_EOK)
489 break;
490 udelay(1);
491 }
492 }
493
494 static void sunhv_console_write_bychar(struct console *con, const char *s, unsigned n)
495 {
496 struct uart_port *port = sunhv_port;
497 unsigned long flags;
498 int i, locked = 1;
499
500 if (port->sysrq || oops_in_progress)
501 locked = spin_trylock_irqsave(&port->lock, flags);
502 else
503 spin_lock_irqsave(&port->lock, flags);
504
505 for (i = 0; i < n; i++) {
506 if (*s == '\n')
507 sunhv_console_putchar(port, '\r');
508 sunhv_console_putchar(port, *s++);
509 }
510
511 if (locked)
512 spin_unlock_irqrestore(&port->lock, flags);
513 }
514
515 static struct console sunhv_console = {
516 .name = "ttyHV",
517 .write = sunhv_console_write_bychar,
518 .device = uart_console_device,
519 .flags = CON_PRINTBUFFER,
520 .index = -1,
521 .data = &sunhv_reg,
522 };
523
524 static int hv_probe(struct platform_device *op)
525 {
526 struct uart_port *port;
527 unsigned long minor;
528 int err;
529
530 if (op->archdata.irqs[0] == 0xffffffff)
531 return -ENODEV;
532
533 port = kzalloc(sizeof(struct uart_port), GFP_KERNEL);
534 if (unlikely(!port))
535 return -ENOMEM;
536
537 minor = 1;
538 if (sun4v_hvapi_register(HV_GRP_CORE, 1, &minor) == 0 &&
539 minor >= 1) {
540 err = -ENOMEM;
541 con_write_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
542 if (!con_write_page)
543 goto out_free_port;
544
545 con_read_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
546 if (!con_read_page)
547 goto out_free_con_write_page;
548
549 sunhv_console.write = sunhv_console_write_paged;
550 sunhv_ops = &bywrite_ops;
551 }
552
553 sunhv_port = port;
554
555 port->line = 0;
556 port->ops = &sunhv_pops;
557 port->type = PORT_SUNHV;
558 port->uartclk = ( 29491200 / 16 ); /* arbitrary */
559
560 port->membase = (unsigned char __iomem *) __pa(port);
561
562 port->irq = op->archdata.irqs[0];
563
564 port->dev = &op->dev;
565
566 err = sunserial_register_minors(&sunhv_reg, 1);
567 if (err)
568 goto out_free_con_read_page;
569
570 sunserial_console_match(&sunhv_console, op->dev.of_node,
571 &sunhv_reg, port->line, false);
572
573 err = uart_add_one_port(&sunhv_reg, port);
574 if (err)
575 goto out_unregister_driver;
576
577 err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port);
578 if (err)
579 goto out_remove_port;
580
581 platform_set_drvdata(op, port);
582
583 return 0;
584
585 out_remove_port:
586 uart_remove_one_port(&sunhv_reg, port);
587
588 out_unregister_driver:
589 sunserial_unregister_minors(&sunhv_reg, 1);
590
591 out_free_con_read_page:
592 kfree(con_read_page);
593
594 out_free_con_write_page:
595 kfree(con_write_page);
596
597 out_free_port:
598 kfree(port);
599 sunhv_port = NULL;
600 return err;
601 }
602
603 static int hv_remove(struct platform_device *dev)
604 {
605 struct uart_port *port = platform_get_drvdata(dev);
606
607 free_irq(port->irq, port);
608
609 uart_remove_one_port(&sunhv_reg, port);
610
611 sunserial_unregister_minors(&sunhv_reg, 1);
612 kfree(con_read_page);
613 kfree(con_write_page);
614 kfree(port);
615 sunhv_port = NULL;
616
617 return 0;
618 }
619
620 static const struct of_device_id hv_match[] = {
621 {
622 .name = "console",
623 .compatible = "qcn",
624 },
625 {
626 .name = "console",
627 .compatible = "SUNW,sun4v-console",
628 },
629 {},
630 };
631
632 static struct platform_driver hv_driver = {
633 .driver = {
634 .name = "hv",
635 .of_match_table = hv_match,
636 },
637 .probe = hv_probe,
638 .remove = hv_remove,
639 };
640
641 static int __init sunhv_init(void)
642 {
643 if (tlb_type != hypervisor)
644 return -ENODEV;
645
646 return platform_driver_register(&hv_driver);
647 }
648 device_initcall(sunhv_init);
649
650 #if 0 /* ...def MODULE ; never supported as such */
651 MODULE_AUTHOR("David S. Miller");
652 MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
653 MODULE_VERSION("2.0");
654 MODULE_LICENSE("GPL");
655 #endif
Linux with added FPC-III support