ia64/linux-2.6.18-xen.hg

view drivers/char/generic_serial.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
2 * generic_serial.c
3 *
4 * Copyright (C) 1998/1999 R.E.Wolff@BitWizard.nl
5 *
6 * written for the SX serial driver.
7 * Contains the code that should be shared over all the serial drivers.
8 *
9 * Credit for the idea to do it this way might go to Alan Cox.
10 *
11 *
12 * Version 0.1 -- December, 1998. Initial version.
13 * Version 0.2 -- March, 1999. Some more routines. Bugfixes. Etc.
14 * Version 0.5 -- August, 1999. Some more fixes. Reformat for Linus.
15 *
16 * BitWizard is actively maintaining this file. We sometimes find
17 * that someone submitted changes to this file. We really appreciate
18 * your help, but please submit changes through us. We're doing our
19 * best to be responsive. -- REW
20 * */
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/tty.h>
25 #include <linux/serial.h>
26 #include <linux/mm.h>
27 #include <linux/generic_serial.h>
28 #include <linux/interrupt.h>
29 #include <linux/tty_flip.h>
30 #include <linux/delay.h>
31 #include <asm/semaphore.h>
32 #include <asm/uaccess.h>
34 #define DEBUG
36 static char * tmp_buf;
38 static int gs_debug;
40 #ifdef DEBUG
41 #define gs_dprintk(f, str...) if (gs_debug & f) printk (str)
42 #else
43 #define gs_dprintk(f, str...) /* nothing */
44 #endif
46 #define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter %s\n", __FUNCTION__)
47 #define func_exit() gs_dprintk (GS_DEBUG_FLOW, "gs: exit %s\n", __FUNCTION__)
48 #define NEW_WRITE_LOCKING 1
49 #if NEW_WRITE_LOCKING
50 #define DECL /* Nothing */
51 #define LOCKIT mutex_lock(& port->port_write_mutex);
52 #define RELEASEIT mutex_unlock(&port->port_write_mutex);
53 #else
54 #define DECL unsigned long flags;
55 #define LOCKIT save_flags (flags);cli ()
56 #define RELEASEIT restore_flags (flags)
57 #endif
59 #define RS_EVENT_WRITE_WAKEUP 1
61 module_param(gs_debug, int, 0644);
64 void gs_put_char(struct tty_struct * tty, unsigned char ch)
65 {
66 struct gs_port *port;
67 DECL
69 func_enter ();
71 if (!tty) return;
73 port = tty->driver_data;
75 if (!port) return;
77 if (! (port->flags & ASYNC_INITIALIZED)) return;
79 /* Take a lock on the serial tranmit buffer! */
80 LOCKIT;
82 if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
83 /* Sorry, buffer is full, drop character. Update statistics???? -- REW */
84 RELEASEIT;
85 return;
86 }
88 port->xmit_buf[port->xmit_head++] = ch;
89 port->xmit_head &= SERIAL_XMIT_SIZE - 1;
90 port->xmit_cnt++; /* Characters in buffer */
92 RELEASEIT;
93 func_exit ();
94 }
97 #ifdef NEW_WRITE_LOCKING
99 /*
100 > Problems to take into account are:
101 > -1- Interrupts that empty part of the buffer.
102 > -2- page faults on the access to userspace.
103 > -3- Other processes that are also trying to do a "write".
104 */
106 int gs_write(struct tty_struct * tty,
107 const unsigned char *buf, int count)
108 {
109 struct gs_port *port;
110 int c, total = 0;
111 int t;
113 func_enter ();
115 if (!tty) return 0;
117 port = tty->driver_data;
119 if (!port) return 0;
121 if (! (port->flags & ASYNC_INITIALIZED))
122 return 0;
124 /* get exclusive "write" access to this port (problem 3) */
125 /* This is not a spinlock because we can have a disk access (page
126 fault) in copy_from_user */
127 mutex_lock(& port->port_write_mutex);
129 while (1) {
131 c = count;
133 /* This is safe because we "OWN" the "head". Noone else can
134 change the "head": we own the port_write_mutex. */
135 /* Don't overrun the end of the buffer */
136 t = SERIAL_XMIT_SIZE - port->xmit_head;
137 if (t < c) c = t;
139 /* This is safe because the xmit_cnt can only decrease. This
140 would increase "t", so we might copy too little chars. */
141 /* Don't copy past the "head" of the buffer */
142 t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt;
143 if (t < c) c = t;
145 /* Can't copy more? break out! */
146 if (c <= 0) break;
148 memcpy (port->xmit_buf + port->xmit_head, buf, c);
150 port -> xmit_cnt += c;
151 port -> xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE -1);
152 buf += c;
153 count -= c;
154 total += c;
155 }
156 mutex_unlock(& port->port_write_mutex);
158 gs_dprintk (GS_DEBUG_WRITE, "write: interrupts are %s\n",
159 (port->flags & GS_TX_INTEN)?"enabled": "disabled");
161 if (port->xmit_cnt &&
162 !tty->stopped &&
163 !tty->hw_stopped &&
164 !(port->flags & GS_TX_INTEN)) {
165 port->flags |= GS_TX_INTEN;
166 port->rd->enable_tx_interrupts (port);
167 }
168 func_exit ();
169 return total;
170 }
171 #else
172 /*
173 > Problems to take into account are:
174 > -1- Interrupts that empty part of the buffer.
175 > -2- page faults on the access to userspace.
176 > -3- Other processes that are also trying to do a "write".
177 */
179 int gs_write(struct tty_struct * tty,
180 const unsigned char *buf, int count)
181 {
182 struct gs_port *port;
183 int c, total = 0;
184 int t;
185 unsigned long flags;
187 func_enter ();
189 /* The standard serial driver returns 0 in this case.
190 That sounds to me as "No error, I just didn't get to writing any
191 bytes. Feel free to try again."
192 The "official" way to write n bytes from buf is:
194 for (nwritten = 0;nwritten < n;nwritten += rv) {
195 rv = write (fd, buf+nwritten, n-nwritten);
196 if (rv < 0) break; // Error: bail out. //
197 }
199 which will loop endlessly in this case. The manual page for write
200 agrees with me. In practise almost everybody writes
201 "write (fd, buf,n);" but some people might have had to deal with
202 incomplete writes in the past and correctly implemented it by now...
203 */
205 if (!tty) return -EIO;
207 port = tty->driver_data;
208 if (!port || !port->xmit_buf || !tmp_buf)
209 return -EIO;
211 local_save_flags(flags);
212 while (1) {
213 cli();
214 c = count;
216 /* This is safe because we "OWN" the "head". Noone else can
217 change the "head": we own the port_write_mutex. */
218 /* Don't overrun the end of the buffer */
219 t = SERIAL_XMIT_SIZE - port->xmit_head;
220 if (t < c) c = t;
222 /* This is safe because the xmit_cnt can only decrease. This
223 would increase "t", so we might copy too little chars. */
224 /* Don't copy past the "head" of the buffer */
225 t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt;
226 if (t < c) c = t;
228 /* Can't copy more? break out! */
229 if (c <= 0) {
230 local_restore_flags(flags);
231 break;
232 }
233 memcpy(port->xmit_buf + port->xmit_head, buf, c);
234 port->xmit_head = ((port->xmit_head + c) &
235 (SERIAL_XMIT_SIZE-1));
236 port->xmit_cnt += c;
237 local_restore_flags(flags);
238 buf += c;
239 count -= c;
240 total += c;
241 }
243 if (port->xmit_cnt &&
244 !tty->stopped &&
245 !tty->hw_stopped &&
246 !(port->flags & GS_TX_INTEN)) {
247 port->flags |= GS_TX_INTEN;
248 port->rd->enable_tx_interrupts (port);
249 }
250 func_exit ();
251 return total;
252 }
254 #endif
258 int gs_write_room(struct tty_struct * tty)
259 {
260 struct gs_port *port = tty->driver_data;
261 int ret;
263 func_enter ();
264 ret = SERIAL_XMIT_SIZE - port->xmit_cnt - 1;
265 if (ret < 0)
266 ret = 0;
267 func_exit ();
268 return ret;
269 }
272 int gs_chars_in_buffer(struct tty_struct *tty)
273 {
274 struct gs_port *port = tty->driver_data;
275 func_enter ();
277 func_exit ();
278 return port->xmit_cnt;
279 }
282 static int gs_real_chars_in_buffer(struct tty_struct *tty)
283 {
284 struct gs_port *port;
285 func_enter ();
287 if (!tty) return 0;
288 port = tty->driver_data;
290 if (!port->rd) return 0;
291 if (!port->rd->chars_in_buffer) return 0;
293 func_exit ();
294 return port->xmit_cnt + port->rd->chars_in_buffer (port);
295 }
298 static int gs_wait_tx_flushed (void * ptr, unsigned long timeout)
299 {
300 struct gs_port *port = ptr;
301 unsigned long end_jiffies;
302 int jiffies_to_transmit, charsleft = 0, rv = 0;
303 int rcib;
305 func_enter();
307 gs_dprintk (GS_DEBUG_FLUSH, "port=%p.\n", port);
308 if (port) {
309 gs_dprintk (GS_DEBUG_FLUSH, "xmit_cnt=%x, xmit_buf=%p, tty=%p.\n",
310 port->xmit_cnt, port->xmit_buf, port->tty);
311 }
313 if (!port || port->xmit_cnt < 0 || !port->xmit_buf) {
314 gs_dprintk (GS_DEBUG_FLUSH, "ERROR: !port, !port->xmit_buf or prot->xmit_cnt < 0.\n");
315 func_exit();
316 return -EINVAL; /* This is an error which we don't know how to handle. */
317 }
319 rcib = gs_real_chars_in_buffer(port->tty);
321 if(rcib <= 0) {
322 gs_dprintk (GS_DEBUG_FLUSH, "nothing to wait for.\n");
323 func_exit();
324 return rv;
325 }
326 /* stop trying: now + twice the time it would normally take + seconds */
327 if (timeout == 0) timeout = MAX_SCHEDULE_TIMEOUT;
328 end_jiffies = jiffies;
329 if (timeout != MAX_SCHEDULE_TIMEOUT)
330 end_jiffies += port->baud?(2 * rcib * 10 * HZ / port->baud):0;
331 end_jiffies += timeout;
333 gs_dprintk (GS_DEBUG_FLUSH, "now=%lx, end=%lx (%ld).\n",
334 jiffies, end_jiffies, end_jiffies-jiffies);
336 /* the expression is actually jiffies < end_jiffies, but that won't
337 work around the wraparound. Tricky eh? */
338 while ((charsleft = gs_real_chars_in_buffer (port->tty)) &&
339 time_after (end_jiffies, jiffies)) {
340 /* Units check:
341 chars * (bits/char) * (jiffies /sec) / (bits/sec) = jiffies!
342 check! */
344 charsleft += 16; /* Allow 16 chars more to be transmitted ... */
345 jiffies_to_transmit = port->baud?(1 + charsleft * 10 * HZ / port->baud):0;
346 /* ^^^ Round up.... */
347 if (jiffies_to_transmit <= 0) jiffies_to_transmit = 1;
349 gs_dprintk (GS_DEBUG_FLUSH, "Expect to finish in %d jiffies "
350 "(%d chars).\n", jiffies_to_transmit, charsleft);
352 msleep_interruptible(jiffies_to_msecs(jiffies_to_transmit));
353 if (signal_pending (current)) {
354 gs_dprintk (GS_DEBUG_FLUSH, "Signal pending. Bombing out: ");
355 rv = -EINTR;
356 break;
357 }
358 }
360 gs_dprintk (GS_DEBUG_FLUSH, "charsleft = %d.\n", charsleft);
361 set_current_state (TASK_RUNNING);
363 func_exit();
364 return rv;
365 }
369 void gs_flush_buffer(struct tty_struct *tty)
370 {
371 struct gs_port *port;
372 unsigned long flags;
374 func_enter ();
376 if (!tty) return;
378 port = tty->driver_data;
380 if (!port) return;
382 /* XXX Would the write semaphore do? */
383 spin_lock_irqsave (&port->driver_lock, flags);
384 port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
385 spin_unlock_irqrestore (&port->driver_lock, flags);
387 wake_up_interruptible(&tty->write_wait);
388 tty_wakeup(tty);
389 func_exit ();
390 }
393 void gs_flush_chars(struct tty_struct * tty)
394 {
395 struct gs_port *port;
397 func_enter ();
399 if (!tty) return;
401 port = tty->driver_data;
403 if (!port) return;
405 if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
406 !port->xmit_buf) {
407 func_exit ();
408 return;
409 }
411 /* Beats me -- REW */
412 port->flags |= GS_TX_INTEN;
413 port->rd->enable_tx_interrupts (port);
414 func_exit ();
415 }
418 void gs_stop(struct tty_struct * tty)
419 {
420 struct gs_port *port;
422 func_enter ();
424 if (!tty) return;
426 port = tty->driver_data;
428 if (!port) return;
430 if (port->xmit_cnt &&
431 port->xmit_buf &&
432 (port->flags & GS_TX_INTEN) ) {
433 port->flags &= ~GS_TX_INTEN;
434 port->rd->disable_tx_interrupts (port);
435 }
436 func_exit ();
437 }
440 void gs_start(struct tty_struct * tty)
441 {
442 struct gs_port *port;
444 if (!tty) return;
446 port = tty->driver_data;
448 if (!port) return;
450 if (port->xmit_cnt &&
451 port->xmit_buf &&
452 !(port->flags & GS_TX_INTEN) ) {
453 port->flags |= GS_TX_INTEN;
454 port->rd->enable_tx_interrupts (port);
455 }
456 func_exit ();
457 }
460 static void gs_shutdown_port (struct gs_port *port)
461 {
462 unsigned long flags;
464 func_enter();
466 if (!port) return;
468 if (!(port->flags & ASYNC_INITIALIZED))
469 return;
471 spin_lock_irqsave(&port->driver_lock, flags);
473 if (port->xmit_buf) {
474 free_page((unsigned long) port->xmit_buf);
475 port->xmit_buf = NULL;
476 }
478 if (port->tty)
479 set_bit(TTY_IO_ERROR, &port->tty->flags);
481 port->rd->shutdown_port (port);
483 port->flags &= ~ASYNC_INITIALIZED;
484 spin_unlock_irqrestore(&port->driver_lock, flags);
486 func_exit();
487 }
490 void gs_hangup(struct tty_struct *tty)
491 {
492 struct gs_port *port;
494 func_enter ();
496 if (!tty) return;
498 port = tty->driver_data;
499 tty = port->tty;
500 if (!tty)
501 return;
503 gs_shutdown_port (port);
504 port->flags &= ~(ASYNC_NORMAL_ACTIVE|GS_ACTIVE);
505 port->tty = NULL;
506 port->count = 0;
508 wake_up_interruptible(&port->open_wait);
509 func_exit ();
510 }
513 int gs_block_til_ready(void *port_, struct file * filp)
514 {
515 struct gs_port *port = port_;
516 DECLARE_WAITQUEUE(wait, current);
517 int retval;
518 int do_clocal = 0;
519 int CD;
520 struct tty_struct *tty;
521 unsigned long flags;
523 func_enter ();
525 if (!port) return 0;
527 tty = port->tty;
529 if (!tty) return 0;
531 gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n");
532 /*
533 * If the device is in the middle of being closed, then block
534 * until it's done, and then try again.
535 */
536 if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
537 interruptible_sleep_on(&port->close_wait);
538 if (port->flags & ASYNC_HUP_NOTIFY)
539 return -EAGAIN;
540 else
541 return -ERESTARTSYS;
542 }
544 gs_dprintk (GS_DEBUG_BTR, "after hung up\n");
546 /*
547 * If non-blocking mode is set, or the port is not enabled,
548 * then make the check up front and then exit.
549 */
550 if ((filp->f_flags & O_NONBLOCK) ||
551 (tty->flags & (1 << TTY_IO_ERROR))) {
552 port->flags |= ASYNC_NORMAL_ACTIVE;
553 return 0;
554 }
556 gs_dprintk (GS_DEBUG_BTR, "after nonblock\n");
558 if (C_CLOCAL(tty))
559 do_clocal = 1;
561 /*
562 * Block waiting for the carrier detect and the line to become
563 * free (i.e., not in use by the callout). While we are in
564 * this loop, port->count is dropped by one, so that
565 * rs_close() knows when to free things. We restore it upon
566 * exit, either normal or abnormal.
567 */
568 retval = 0;
570 add_wait_queue(&port->open_wait, &wait);
572 gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n");
573 spin_lock_irqsave(&port->driver_lock, flags);
574 if (!tty_hung_up_p(filp)) {
575 port->count--;
576 }
577 spin_unlock_irqrestore(&port->driver_lock, flags);
578 port->blocked_open++;
579 while (1) {
580 CD = port->rd->get_CD (port);
581 gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD);
582 set_current_state (TASK_INTERRUPTIBLE);
583 if (tty_hung_up_p(filp) ||
584 !(port->flags & ASYNC_INITIALIZED)) {
585 if (port->flags & ASYNC_HUP_NOTIFY)
586 retval = -EAGAIN;
587 else
588 retval = -ERESTARTSYS;
589 break;
590 }
591 if (!(port->flags & ASYNC_CLOSING) &&
592 (do_clocal || CD))
593 break;
594 gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n",
595 (int)signal_pending (current), *(long*)(&current->blocked));
596 if (signal_pending(current)) {
597 retval = -ERESTARTSYS;
598 break;
599 }
600 schedule();
601 }
602 gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n",
603 port->blocked_open);
604 set_current_state (TASK_RUNNING);
605 remove_wait_queue(&port->open_wait, &wait);
606 if (!tty_hung_up_p(filp)) {
607 port->count++;
608 }
609 port->blocked_open--;
610 if (retval)
611 return retval;
613 port->flags |= ASYNC_NORMAL_ACTIVE;
614 func_exit ();
615 return 0;
616 }
619 void gs_close(struct tty_struct * tty, struct file * filp)
620 {
621 unsigned long flags;
622 struct gs_port *port;
624 func_enter ();
626 if (!tty) return;
628 port = (struct gs_port *) tty->driver_data;
630 if (!port) return;
632 if (!port->tty) {
633 /* This seems to happen when this is called from vhangup. */
634 gs_dprintk (GS_DEBUG_CLOSE, "gs: Odd: port->tty is NULL\n");
635 port->tty = tty;
636 }
638 spin_lock_irqsave(&port->driver_lock, flags);
640 if (tty_hung_up_p(filp)) {
641 spin_unlock_irqrestore(&port->driver_lock, flags);
642 if (port->rd->hungup)
643 port->rd->hungup (port);
644 func_exit ();
645 return;
646 }
648 if ((tty->count == 1) && (port->count != 1)) {
649 printk(KERN_ERR "gs: gs_close port %p: bad port count;"
650 " tty->count is 1, port count is %d\n", port, port->count);
651 port->count = 1;
652 }
653 if (--port->count < 0) {
654 printk(KERN_ERR "gs: gs_close port %p: bad port count: %d\n", port, port->count);
655 port->count = 0;
656 }
658 if (port->count) {
659 gs_dprintk(GS_DEBUG_CLOSE, "gs_close port %p: count: %d\n", port, port->count);
660 spin_unlock_irqrestore(&port->driver_lock, flags);
661 func_exit ();
662 return;
663 }
664 port->flags |= ASYNC_CLOSING;
666 /*
667 * Now we wait for the transmit buffer to clear; and we notify
668 * the line discipline to only process XON/XOFF characters.
669 */
670 tty->closing = 1;
671 /* if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
672 tty_wait_until_sent(tty, port->closing_wait); */
674 /*
675 * At this point we stop accepting input. To do this, we
676 * disable the receive line status interrupts, and tell the
677 * interrupt driver to stop checking the data ready bit in the
678 * line status register.
679 */
681 port->rd->disable_rx_interrupts (port);
682 spin_unlock_irqrestore(&port->driver_lock, flags);
684 /* close has no way of returning "EINTR", so discard return value */
685 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
686 gs_wait_tx_flushed (port, port->closing_wait);
688 port->flags &= ~GS_ACTIVE;
690 if (tty->driver->flush_buffer)
691 tty->driver->flush_buffer(tty);
693 tty_ldisc_flush(tty);
694 tty->closing = 0;
696 port->event = 0;
697 port->rd->close (port);
698 port->rd->shutdown_port (port);
699 port->tty = NULL;
701 if (port->blocked_open) {
702 if (port->close_delay) {
703 spin_unlock_irqrestore(&port->driver_lock, flags);
704 msleep_interruptible(jiffies_to_msecs(port->close_delay));
705 spin_lock_irqsave(&port->driver_lock, flags);
706 }
707 wake_up_interruptible(&port->open_wait);
708 }
709 port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING | ASYNC_INITIALIZED);
710 wake_up_interruptible(&port->close_wait);
712 func_exit ();
713 }
716 static unsigned int gs_baudrates[] = {
717 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
718 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
719 };
722 void gs_set_termios (struct tty_struct * tty,
723 struct termios * old_termios)
724 {
725 struct gs_port *port;
726 int baudrate, tmp, rv;
727 struct termios *tiosp;
729 func_enter();
731 if (!tty) return;
733 port = tty->driver_data;
735 if (!port) return;
736 if (!port->tty) {
737 /* This seems to happen when this is called after gs_close. */
738 gs_dprintk (GS_DEBUG_TERMIOS, "gs: Odd: port->tty is NULL\n");
739 port->tty = tty;
740 }
743 tiosp = tty->termios;
745 if (gs_debug & GS_DEBUG_TERMIOS) {
746 gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp);
747 }
749 #if 0
750 /* This is an optimization that is only allowed for dumb cards */
751 /* Smart cards require knowledge of iflags and oflags too: that
752 might change hardware cooking mode.... */
753 #endif
754 if (old_termios) {
755 if( (tiosp->c_iflag == old_termios->c_iflag)
756 && (tiosp->c_oflag == old_termios->c_oflag)
757 && (tiosp->c_cflag == old_termios->c_cflag)
758 && (tiosp->c_lflag == old_termios->c_lflag)
759 && (tiosp->c_line == old_termios->c_line)
760 && (memcmp(tiosp->c_cc, old_termios->c_cc, NCC) == 0)) {
761 gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: optimized away\n");
762 return /* 0 */;
763 }
764 } else
765 gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: no old_termios: "
766 "no optimization\n");
768 if(old_termios && (gs_debug & GS_DEBUG_TERMIOS)) {
769 if(tiosp->c_iflag != old_termios->c_iflag) printk("c_iflag changed\n");
770 if(tiosp->c_oflag != old_termios->c_oflag) printk("c_oflag changed\n");
771 if(tiosp->c_cflag != old_termios->c_cflag) printk("c_cflag changed\n");
772 if(tiosp->c_lflag != old_termios->c_lflag) printk("c_lflag changed\n");
773 if(tiosp->c_line != old_termios->c_line) printk("c_line changed\n");
774 if(!memcmp(tiosp->c_cc, old_termios->c_cc, NCC)) printk("c_cc changed\n");
775 }
777 baudrate = tiosp->c_cflag & CBAUD;
778 if (baudrate & CBAUDEX) {
779 baudrate &= ~CBAUDEX;
780 if ((baudrate < 1) || (baudrate > 4))
781 tiosp->c_cflag &= ~CBAUDEX;
782 else
783 baudrate += 15;
784 }
786 baudrate = gs_baudrates[baudrate];
787 if ((tiosp->c_cflag & CBAUD) == B38400) {
788 if ( (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
789 baudrate = 57600;
790 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
791 baudrate = 115200;
792 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
793 baudrate = 230400;
794 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
795 baudrate = 460800;
796 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
797 baudrate = (port->baud_base / port->custom_divisor);
798 }
800 /* I recommend using THIS instead of the mess in termios (and
801 duplicating the above code). Next we should create a clean
802 interface towards this variable. If your card supports arbitrary
803 baud rates, (e.g. CD1400 or 16550 based cards) then everything
804 will be very easy..... */
805 port->baud = baudrate;
807 /* Two timer ticks seems enough to wakeup something like SLIP driver */
808 /* Baudrate/10 is cps. Divide by HZ to get chars per tick. */
809 tmp = (baudrate / 10 / HZ) * 2;
811 if (tmp < 0) tmp = 0;
812 if (tmp >= SERIAL_XMIT_SIZE) tmp = SERIAL_XMIT_SIZE-1;
814 port->wakeup_chars = tmp;
816 /* We should really wait for the characters to be all sent before
817 changing the settings. -- CAL */
818 rv = gs_wait_tx_flushed (port, MAX_SCHEDULE_TIMEOUT);
819 if (rv < 0) return /* rv */;
821 rv = port->rd->set_real_termios(port);
822 if (rv < 0) return /* rv */;
824 if ((!old_termios ||
825 (old_termios->c_cflag & CRTSCTS)) &&
826 !( tiosp->c_cflag & CRTSCTS)) {
827 tty->stopped = 0;
828 gs_start(tty);
829 }
831 #ifdef tytso_patch_94Nov25_1726
832 /* This "makes sense", Why is it commented out? */
834 if (!(old_termios->c_cflag & CLOCAL) &&
835 (tty->termios->c_cflag & CLOCAL))
836 wake_up_interruptible(&port->gs.open_wait);
837 #endif
839 func_exit();
840 return /* 0 */;
841 }
845 /* Must be called with interrupts enabled */
846 int gs_init_port(struct gs_port *port)
847 {
848 unsigned long flags;
849 unsigned long page;
851 func_enter ();
853 if (!tmp_buf) {
854 page = get_zeroed_page(GFP_KERNEL);
855 spin_lock_irqsave (&port->driver_lock, flags); /* Don't expect this to make a difference. */
856 if (tmp_buf)
857 free_page(page);
858 else
859 tmp_buf = (unsigned char *) page;
860 spin_unlock_irqrestore (&port->driver_lock, flags);
861 if (!tmp_buf) {
862 func_exit ();
863 return -ENOMEM;
864 }
865 }
867 if (port->flags & ASYNC_INITIALIZED) {
868 func_exit ();
869 return 0;
870 }
871 if (!port->xmit_buf) {
872 /* We may sleep in get_zeroed_page() */
873 unsigned long tmp;
875 tmp = get_zeroed_page(GFP_KERNEL);
876 spin_lock_irqsave (&port->driver_lock, flags);
877 if (port->xmit_buf)
878 free_page (tmp);
879 else
880 port->xmit_buf = (unsigned char *) tmp;
881 spin_unlock_irqrestore(&port->driver_lock, flags);
882 if (!port->xmit_buf) {
883 func_exit ();
884 return -ENOMEM;
885 }
886 }
888 spin_lock_irqsave (&port->driver_lock, flags);
889 if (port->tty)
890 clear_bit(TTY_IO_ERROR, &port->tty->flags);
891 mutex_init(&port->port_write_mutex);
892 port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
893 spin_unlock_irqrestore(&port->driver_lock, flags);
894 gs_set_termios(port->tty, NULL);
895 spin_lock_irqsave (&port->driver_lock, flags);
896 port->flags |= ASYNC_INITIALIZED;
897 port->flags &= ~GS_TX_INTEN;
899 spin_unlock_irqrestore(&port->driver_lock, flags);
900 func_exit ();
901 return 0;
902 }
905 int gs_setserial(struct gs_port *port, struct serial_struct __user *sp)
906 {
907 struct serial_struct sio;
909 if (copy_from_user(&sio, sp, sizeof(struct serial_struct)))
910 return(-EFAULT);
912 if (!capable(CAP_SYS_ADMIN)) {
913 if ((sio.baud_base != port->baud_base) ||
914 (sio.close_delay != port->close_delay) ||
915 ((sio.flags & ~ASYNC_USR_MASK) !=
916 (port->flags & ~ASYNC_USR_MASK)))
917 return(-EPERM);
918 }
920 port->flags = (port->flags & ~ASYNC_USR_MASK) |
921 (sio.flags & ASYNC_USR_MASK);
923 port->baud_base = sio.baud_base;
924 port->close_delay = sio.close_delay;
925 port->closing_wait = sio.closing_wait;
926 port->custom_divisor = sio.custom_divisor;
928 gs_set_termios (port->tty, NULL);
930 return 0;
931 }
934 /*****************************************************************************/
936 /*
937 * Generate the serial struct info.
938 */
940 int gs_getserial(struct gs_port *port, struct serial_struct __user *sp)
941 {
942 struct serial_struct sio;
944 memset(&sio, 0, sizeof(struct serial_struct));
945 sio.flags = port->flags;
946 sio.baud_base = port->baud_base;
947 sio.close_delay = port->close_delay;
948 sio.closing_wait = port->closing_wait;
949 sio.custom_divisor = port->custom_divisor;
950 sio.hub6 = 0;
952 /* If you want you can override these. */
953 sio.type = PORT_UNKNOWN;
954 sio.xmit_fifo_size = -1;
955 sio.line = -1;
956 sio.port = -1;
957 sio.irq = -1;
959 if (port->rd->getserial)
960 port->rd->getserial (port, &sio);
962 if (copy_to_user(sp, &sio, sizeof(struct serial_struct)))
963 return -EFAULT;
964 return 0;
966 }
969 void gs_got_break(struct gs_port *port)
970 {
971 func_enter ();
973 tty_insert_flip_char(port->tty, 0, TTY_BREAK);
974 tty_schedule_flip(port->tty);
975 if (port->flags & ASYNC_SAK) {
976 do_SAK (port->tty);
977 }
979 func_exit ();
980 }
983 EXPORT_SYMBOL(gs_put_char);
984 EXPORT_SYMBOL(gs_write);
985 EXPORT_SYMBOL(gs_write_room);
986 EXPORT_SYMBOL(gs_chars_in_buffer);
987 EXPORT_SYMBOL(gs_flush_buffer);
988 EXPORT_SYMBOL(gs_flush_chars);
989 EXPORT_SYMBOL(gs_stop);
990 EXPORT_SYMBOL(gs_start);
991 EXPORT_SYMBOL(gs_hangup);
992 EXPORT_SYMBOL(gs_block_til_ready);
993 EXPORT_SYMBOL(gs_close);
994 EXPORT_SYMBOL(gs_set_termios);
995 EXPORT_SYMBOL(gs_init_port);
996 EXPORT_SYMBOL(gs_setserial);
997 EXPORT_SYMBOL(gs_getserial);
998 EXPORT_SYMBOL(gs_got_break);
1000 MODULE_LICENSE("GPL");