]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - arch/um/drivers/line.c
015209a9881529bd9495460338b048f65adc7994
2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include "linux/irqreturn.h"
8 #include "linux/sched.h"
9 #include "linux/slab.h"
13 #include "kern_util.h"
16 #define LINE_BUFSIZE 4096
18 static irqreturn_t
line_interrupt(int irq
, void *data
)
20 struct chan
*chan
= data
;
21 struct line
*line
= chan
->line
;
24 chan_interrupt(&line
->chan_list
, &line
->task
, line
->tty
, irq
);
28 static void line_timer_cb(struct work_struct
*work
)
30 struct line
*line
= container_of(work
, struct line
, task
.work
);
33 chan_interrupt(&line
->chan_list
, &line
->task
, line
->tty
,
34 line
->driver
->read_irq
);
38 * Returns the free space inside the ring buffer of this line.
40 * Should be called while holding line->lock (this does not modify data).
42 static int write_room(struct line
*line
)
46 if (line
->buffer
== NULL
)
47 return LINE_BUFSIZE
- 1;
49 /* This is for the case where the buffer is wrapped! */
50 n
= line
->head
- line
->tail
;
53 n
+= LINE_BUFSIZE
; /* The other case */
57 int line_write_room(struct tty_struct
*tty
)
59 struct line
*line
= tty
->driver_data
;
63 spin_lock_irqsave(&line
->lock
, flags
);
64 room
= write_room(line
);
65 spin_unlock_irqrestore(&line
->lock
, flags
);
70 int line_chars_in_buffer(struct tty_struct
*tty
)
72 struct line
*line
= tty
->driver_data
;
76 spin_lock_irqsave(&line
->lock
, flags
);
77 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
78 ret
= LINE_BUFSIZE
- (write_room(line
) + 1);
79 spin_unlock_irqrestore(&line
->lock
, flags
);
85 * This copies the content of buf into the circular buffer associated with
87 * The return value is the number of characters actually copied, i.e. the ones
88 * for which there was space: this function is not supposed to ever flush out
89 * the circular buffer.
91 * Must be called while holding line->lock!
93 static int buffer_data(struct line
*line
, const char *buf
, int len
)
97 if (line
->buffer
== NULL
) {
98 line
->buffer
= kmalloc(LINE_BUFSIZE
, GFP_ATOMIC
);
99 if (line
->buffer
== NULL
) {
100 printk(KERN_ERR
"buffer_data - atomic allocation "
104 line
->head
= line
->buffer
;
105 line
->tail
= line
->buffer
;
108 room
= write_room(line
);
109 len
= (len
> room
) ? room
: len
;
111 end
= line
->buffer
+ LINE_BUFSIZE
- line
->tail
;
114 memcpy(line
->tail
, buf
, len
);
118 /* The circular buffer is wrapping */
119 memcpy(line
->tail
, buf
, end
);
121 memcpy(line
->buffer
, buf
, len
- end
);
122 line
->tail
= line
->buffer
+ len
- end
;
129 * Flushes the ring buffer to the output channels. That is, write_chan is
130 * called, passing it line->head as buffer, and an appropriate count.
132 * On exit, returns 1 when the buffer is empty,
133 * 0 when the buffer is not empty on exit,
134 * and -errno when an error occurred.
136 * Must be called while holding line->lock!*/
137 static int flush_buffer(struct line
*line
)
141 if ((line
->buffer
== NULL
) || (line
->head
== line
->tail
))
144 if (line
->tail
< line
->head
) {
145 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
146 count
= line
->buffer
+ LINE_BUFSIZE
- line
->head
;
148 n
= write_chan(&line
->chan_list
, line
->head
, count
,
149 line
->driver
->write_irq
);
154 * We have flushed from ->head to buffer end, now we
155 * must flush only from the beginning to ->tail.
157 line
->head
= line
->buffer
;
164 count
= line
->tail
- line
->head
;
165 n
= write_chan(&line
->chan_list
, line
->head
, count
,
166 line
->driver
->write_irq
);
172 return line
->head
== line
->tail
;
175 void line_flush_buffer(struct tty_struct
*tty
)
177 struct line
*line
= tty
->driver_data
;
180 spin_lock_irqsave(&line
->lock
, flags
);
182 spin_unlock_irqrestore(&line
->lock
, flags
);
186 * We map both ->flush_chars and ->put_char (which go in pair) onto
187 * ->flush_buffer and ->write. Hope it's not that bad.
189 void line_flush_chars(struct tty_struct
*tty
)
191 line_flush_buffer(tty
);
194 int line_put_char(struct tty_struct
*tty
, unsigned char ch
)
196 return line_write(tty
, &ch
, sizeof(ch
));
199 int line_write(struct tty_struct
*tty
, const unsigned char *buf
, int len
)
201 struct line
*line
= tty
->driver_data
;
205 spin_lock_irqsave(&line
->lock
, flags
);
206 if (line
->head
!= line
->tail
)
207 ret
= buffer_data(line
, buf
, len
);
209 n
= write_chan(&line
->chan_list
, buf
, len
,
210 line
->driver
->write_irq
);
219 ret
+= buffer_data(line
, buf
+ n
, len
);
222 spin_unlock_irqrestore(&line
->lock
, flags
);
226 void line_set_termios(struct tty_struct
*tty
, struct ktermios
* old
)
231 static const struct {
236 /* don't print these, they flood the log ... */
237 { TCGETS
, NULL
, "TCGETS" },
238 { TCSETS
, NULL
, "TCSETS" },
239 { TCSETSW
, NULL
, "TCSETSW" },
240 { TCFLSH
, NULL
, "TCFLSH" },
241 { TCSBRK
, NULL
, "TCSBRK" },
243 /* general tty stuff */
244 { TCSETSF
, KERN_DEBUG
, "TCSETSF" },
245 { TCGETA
, KERN_DEBUG
, "TCGETA" },
246 { TIOCMGET
, KERN_DEBUG
, "TIOCMGET" },
247 { TCSBRKP
, KERN_DEBUG
, "TCSBRKP" },
248 { TIOCMSET
, KERN_DEBUG
, "TIOCMSET" },
250 /* linux-specific ones */
251 { TIOCLINUX
, KERN_INFO
, "TIOCLINUX" },
252 { KDGKBMODE
, KERN_INFO
, "KDGKBMODE" },
253 { KDGKBTYPE
, KERN_INFO
, "KDGKBTYPE" },
254 { KDSIGACCEPT
, KERN_INFO
, "KDSIGACCEPT" },
257 int line_ioctl(struct tty_struct
*tty
, unsigned int cmd
,
278 /* Note: these are out of date as we now have TCGETS2 etc but this
279 whole lot should probably go away */
304 for (i
= 0; i
< ARRAY_SIZE(tty_ioctls
); i
++)
305 if (cmd
== tty_ioctls
[i
].cmd
)
307 if (i
== ARRAY_SIZE(tty_ioctls
)) {
308 printk(KERN_ERR
"%s: %s: unknown ioctl: 0x%x\n",
309 __func__
, tty
->name
, cmd
);
317 void line_throttle(struct tty_struct
*tty
)
319 struct line
*line
= tty
->driver_data
;
321 deactivate_chan(&line
->chan_list
, line
->driver
->read_irq
);
325 void line_unthrottle(struct tty_struct
*tty
)
327 struct line
*line
= tty
->driver_data
;
330 chan_interrupt(&line
->chan_list
, &line
->task
, tty
,
331 line
->driver
->read_irq
);
334 * Maybe there is enough stuff pending that calling the interrupt
335 * throttles us again. In this case, line->throttled will be 1
336 * again and we shouldn't turn the interrupt back on.
338 if (!line
->throttled
)
339 reactivate_chan(&line
->chan_list
, line
->driver
->read_irq
);
342 static irqreturn_t
line_write_interrupt(int irq
, void *data
)
344 struct chan
*chan
= data
;
345 struct line
*line
= chan
->line
;
346 struct tty_struct
*tty
= line
->tty
;
350 * Interrupts are disabled here because genirq keep irqs disabled when
351 * calling the action handler.
354 spin_lock(&line
->lock
);
355 err
= flush_buffer(line
);
358 } else if (err
< 0) {
359 line
->head
= line
->buffer
;
360 line
->tail
= line
->buffer
;
362 spin_unlock(&line
->lock
);
371 int line_setup_irq(int fd
, int input
, int output
, struct line
*line
, void *data
)
373 const struct line_driver
*driver
= line
->driver
;
374 int err
= 0, flags
= IRQF_SHARED
| IRQF_SAMPLE_RANDOM
;
377 err
= um_request_irq(driver
->read_irq
, fd
, IRQ_READ
,
378 line_interrupt
, flags
,
379 driver
->read_irq_name
, data
);
383 err
= um_request_irq(driver
->write_irq
, fd
, IRQ_WRITE
,
384 line_write_interrupt
, flags
,
385 driver
->write_irq_name
, data
);
391 * Normally, a driver like this can rely mostly on the tty layer
392 * locking, particularly when it comes to the driver structure.
393 * However, in this case, mconsole requests can come in "from the
394 * side", and race with opens and closes.
396 * mconsole config requests will want to be sure the device isn't in
397 * use, and get_config, open, and close will want a stable
398 * configuration. The checking and modification of the configuration
399 * is done under a spinlock. Checking whether the device is in use is
400 * line->tty->count > 1, also under the spinlock.
402 * line->count serves to decide whether the device should be enabled or
403 * disabled on the host. If it's equal to 0, then we are doing the
404 * first open or last close. Otherwise, open and close just return.
407 int line_open(struct line
*lines
, struct tty_struct
*tty
)
409 struct line
*line
= &lines
[tty
->index
];
412 mutex_lock(&line
->count_lock
);
420 BUG_ON(tty
->driver_data
);
421 tty
->driver_data
= line
;
424 err
= enable_chan(line
);
425 if (err
) /* line_close() will be called by our caller */
428 INIT_DELAYED_WORK(&line
->task
, line_timer_cb
);
431 chan_enable_winch(&line
->chan_list
, tty
);
435 chan_window_size(&line
->chan_list
, &tty
->winsize
.ws_row
,
436 &tty
->winsize
.ws_col
);
438 mutex_unlock(&line
->count_lock
);
442 static void unregister_winch(struct tty_struct
*tty
);
444 void line_close(struct tty_struct
*tty
, struct file
* filp
)
446 struct line
*line
= tty
->driver_data
;
449 * If line_open fails (and tty->driver_data is never set),
450 * tty_open will call line_close. So just return in this case.
455 /* We ignore the error anyway! */
458 mutex_lock(&line
->count_lock
);
459 BUG_ON(!line
->valid
);
465 tty
->driver_data
= NULL
;
468 unregister_winch(tty
);
473 mutex_unlock(&line
->count_lock
);
476 void close_lines(struct line
*lines
, int nlines
)
480 for(i
= 0; i
< nlines
; i
++)
481 close_chan(&lines
[i
].chan_list
, 0);
484 static int setup_one_line(struct line
*lines
, int n
, char *init
,
485 const struct chan_opts
*opts
, char **error_out
)
487 struct line
*line
= &lines
[n
];
488 struct tty_driver
*driver
= line
->driver
->driver
;
491 mutex_lock(&line
->count_lock
);
494 *error_out
= "Device is already open";
498 if (!strcmp(init
, "none")) {
501 kfree(line
->init_str
);
502 tty_unregister_device(driver
, n
);
503 parse_chan_pair(NULL
, line
, n
, opts
, error_out
);
507 char *new = kstrdup(init
, GFP_KERNEL
);
509 *error_out
= "Failed to allocate memory";
513 tty_unregister_device(driver
, n
);
514 line
->init_str
= new;
516 err
= parse_chan_pair(new, line
, n
, opts
, error_out
);
518 struct device
*d
= tty_register_device(driver
, n
, NULL
);
520 *error_out
= "Failed to register device";
522 parse_chan_pair(NULL
, line
, n
, opts
, error_out
);
526 line
->init_str
= NULL
;
532 mutex_unlock(&line
->count_lock
);
537 * Common setup code for both startup command line and mconsole initialization.
538 * @lines contains the array (of size @num) to modify;
539 * @init is the setup string;
540 * @error_out is an error string in the case of failure;
543 int line_setup(char **conf
, unsigned int num
, char **def
,
544 char *init
, char *name
)
550 * We said con=/ssl= instead of con#=, so we are configuring all
556 unsigned n
= simple_strtoul(init
, &end
, 0);
559 error
= "Couldn't parse device number";
563 error
= "Device number out of range";
571 printk(KERN_ERR
"Failed to set up %s with "
572 "configuration string \"%s\" : %s\n", name
, init
, error
);
576 int line_config(struct line
*lines
, unsigned int num
, char *str
,
577 const struct chan_opts
*opts
, char **error_out
)
583 *error_out
= "Can't configure all devices from mconsole";
587 n
= simple_strtoul(str
, &end
, 0);
589 *error_out
= "Couldn't parse device number";
593 *error_out
= "Device number out of range";
597 return setup_one_line(lines
, n
, end
, opts
, error_out
);
600 int line_get_config(char *name
, struct line
*lines
, unsigned int num
, char *str
,
601 int size
, char **error_out
)
607 dev
= simple_strtoul(name
, &end
, 0);
608 if ((*end
!= '\0') || (end
== name
)) {
609 *error_out
= "line_get_config failed to parse device number";
613 if ((dev
< 0) || (dev
>= num
)) {
614 *error_out
= "device number out of range";
620 mutex_lock(&line
->count_lock
);
622 CONFIG_CHUNK(str
, size
, n
, "none", 1);
623 else if (line
->tty
== NULL
)
624 CONFIG_CHUNK(str
, size
, n
, line
->init_str
, 1);
625 else n
= chan_config_string(&line
->chan_list
, str
, size
, error_out
);
626 mutex_unlock(&line
->count_lock
);
631 int line_id(char **str
, int *start_out
, int *end_out
)
636 n
= simple_strtoul(*str
, &end
, 0);
637 if ((*end
!= '\0') || (end
== *str
))
646 int line_remove(struct line
*lines
, unsigned int num
, int n
, char **error_out
)
649 *error_out
= "Device number out of range";
652 return setup_one_line(lines
, n
, "none", NULL
, error_out
);
655 int register_lines(struct line_driver
*line_driver
,
656 const struct tty_operations
*ops
,
657 struct line
*lines
, int nlines
)
659 struct tty_driver
*driver
= alloc_tty_driver(nlines
);
665 driver
->driver_name
= line_driver
->name
;
666 driver
->name
= line_driver
->device_name
;
667 driver
->major
= line_driver
->major
;
668 driver
->minor_start
= line_driver
->minor_start
;
669 driver
->type
= line_driver
->type
;
670 driver
->subtype
= line_driver
->subtype
;
671 driver
->flags
= TTY_DRIVER_REAL_RAW
| TTY_DRIVER_DYNAMIC_DEV
;
672 driver
->init_termios
= tty_std_termios
;
673 tty_set_operations(driver
, ops
);
675 err
= tty_register_driver(driver
);
677 printk(KERN_ERR
"register_lines : can't register %s driver\n",
679 put_tty_driver(driver
);
683 line_driver
->driver
= driver
;
684 mconsole_register_dev(&line_driver
->mc
);
688 static DEFINE_SPINLOCK(winch_handler_lock
);
689 static LIST_HEAD(winch_handlers
);
691 void lines_init(struct line
*lines
, int nlines
, struct chan_opts
*opts
)
697 for(i
= 0; i
< nlines
; i
++) {
699 INIT_LIST_HEAD(&line
->chan_list
);
701 if (line
->init_str
== NULL
)
704 if (setup_one_line(lines
, i
, line
->init_str
, opts
, &error
))
705 printk(KERN_ERR
"setup_one_line failed for "
706 "device %d : %s\n", i
, error
);
711 struct list_head list
;
715 struct tty_struct
*tty
;
717 struct work_struct work
;
720 static void __free_winch(struct work_struct
*work
)
722 struct winch
*winch
= container_of(work
, struct winch
, work
);
723 free_irq(WINCH_IRQ
, winch
);
725 if (winch
->pid
!= -1)
726 os_kill_process(winch
->pid
, 1);
727 if (winch
->stack
!= 0)
728 free_stack(winch
->stack
, 0);
732 static void free_winch(struct winch
*winch
)
738 list_del(&winch
->list
);
739 __free_winch(&winch
->work
);
742 static irqreturn_t
winch_interrupt(int irq
, void *data
)
744 struct winch
*winch
= data
;
745 struct tty_struct
*tty
;
752 err
= generic_read(fd
, &c
, NULL
);
754 if (err
!= -EAGAIN
) {
756 list_del(&winch
->list
);
758 printk(KERN_ERR
"winch_interrupt : "
759 "read failed, errno = %d\n", -err
);
760 printk(KERN_ERR
"fd %d is losing SIGWINCH "
761 "support\n", winch
->tty_fd
);
762 INIT_WORK(&winch
->work
, __free_winch
);
763 schedule_work(&winch
->work
);
771 line
= tty
->driver_data
;
773 chan_window_size(&line
->chan_list
, &tty
->winsize
.ws_row
,
774 &tty
->winsize
.ws_col
);
775 kill_pgrp(tty
->pgrp
, SIGWINCH
, 1);
780 reactivate_fd(winch
->fd
, WINCH_IRQ
);
784 void register_winch_irq(int fd
, int tty_fd
, int pid
, struct tty_struct
*tty
,
789 winch
= kmalloc(sizeof(*winch
), GFP_KERNEL
);
791 printk(KERN_ERR
"register_winch_irq - kmalloc failed\n");
795 *winch
= ((struct winch
) { .list
= LIST_HEAD_INIT(winch
->list
),
802 if (um_request_irq(WINCH_IRQ
, fd
, IRQ_READ
, winch_interrupt
,
803 IRQF_SHARED
| IRQF_SAMPLE_RANDOM
,
804 "winch", winch
) < 0) {
805 printk(KERN_ERR
"register_winch_irq - failed to register "
810 spin_lock(&winch_handler_lock
);
811 list_add(&winch
->list
, &winch_handlers
);
812 spin_unlock(&winch_handler_lock
);
819 os_kill_process(pid
, 1);
822 free_stack(stack
, 0);
825 static void unregister_winch(struct tty_struct
*tty
)
827 struct list_head
*ele
, *next
;
830 spin_lock(&winch_handler_lock
);
832 list_for_each_safe(ele
, next
, &winch_handlers
) {
833 winch
= list_entry(ele
, struct winch
, list
);
834 if (winch
->tty
== tty
) {
839 spin_unlock(&winch_handler_lock
);
842 static void winch_cleanup(void)
844 struct list_head
*ele
, *next
;
847 spin_lock(&winch_handler_lock
);
849 list_for_each_safe(ele
, next
, &winch_handlers
) {
850 winch
= list_entry(ele
, struct winch
, list
);
854 spin_unlock(&winch_handler_lock
);
856 __uml_exitcall(winch_cleanup
);
858 char *add_xterm_umid(char *base
)
867 len
= strlen(base
) + strlen(" ()") + strlen(umid
) + 1;
868 title
= kmalloc(len
, GFP_KERNEL
);
870 printk(KERN_ERR
"Failed to allocate buffer for xterm title\n");
874 snprintf(title
, len
, "%s (%s)", base
, umid
);