1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 #include <linux/irqreturn.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
14 #include <kern_util.h>
17 #define LINE_BUFSIZE 4096
19 static irqreturn_t
line_interrupt(int irq
, void *data
)
21 struct chan
*chan
= data
;
22 struct line
*line
= chan
->line
;
25 chan_interrupt(line
, irq
);
31 * Returns the free space inside the ring buffer of this line.
33 * Should be called while holding line->lock (this does not modify data).
35 static unsigned int write_room(struct line
*line
)
39 if (line
->buffer
== NULL
)
40 return LINE_BUFSIZE
- 1;
42 /* This is for the case where the buffer is wrapped! */
43 n
= line
->head
- line
->tail
;
46 n
+= LINE_BUFSIZE
; /* The other case */
50 unsigned int line_write_room(struct tty_struct
*tty
)
52 struct line
*line
= tty
->driver_data
;
56 spin_lock_irqsave(&line
->lock
, flags
);
57 room
= write_room(line
);
58 spin_unlock_irqrestore(&line
->lock
, flags
);
63 unsigned int line_chars_in_buffer(struct tty_struct
*tty
)
65 struct line
*line
= tty
->driver_data
;
69 spin_lock_irqsave(&line
->lock
, flags
);
70 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
71 ret
= LINE_BUFSIZE
- (write_room(line
) + 1);
72 spin_unlock_irqrestore(&line
->lock
, flags
);
78 * This copies the content of buf into the circular buffer associated with
80 * The return value is the number of characters actually copied, i.e. the ones
81 * for which there was space: this function is not supposed to ever flush out
82 * the circular buffer.
84 * Must be called while holding line->lock!
86 static int buffer_data(struct line
*line
, const char *buf
, int len
)
90 if (line
->buffer
== NULL
) {
91 line
->buffer
= kmalloc(LINE_BUFSIZE
, GFP_ATOMIC
);
92 if (line
->buffer
== NULL
) {
93 printk(KERN_ERR
"buffer_data - atomic allocation "
97 line
->head
= line
->buffer
;
98 line
->tail
= line
->buffer
;
101 room
= write_room(line
);
102 len
= (len
> room
) ? room
: len
;
104 end
= line
->buffer
+ LINE_BUFSIZE
- line
->tail
;
107 memcpy(line
->tail
, buf
, len
);
111 /* The circular buffer is wrapping */
112 memcpy(line
->tail
, buf
, end
);
114 memcpy(line
->buffer
, buf
, len
- end
);
115 line
->tail
= line
->buffer
+ len
- end
;
122 * Flushes the ring buffer to the output channels. That is, write_chan is
123 * called, passing it line->head as buffer, and an appropriate count.
125 * On exit, returns 1 when the buffer is empty,
126 * 0 when the buffer is not empty on exit,
127 * and -errno when an error occurred.
129 * Must be called while holding line->lock!*/
130 static int flush_buffer(struct line
*line
)
134 if ((line
->buffer
== NULL
) || (line
->head
== line
->tail
))
137 if (line
->tail
< line
->head
) {
138 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
139 count
= line
->buffer
+ LINE_BUFSIZE
- line
->head
;
141 n
= write_chan(line
->chan_out
, line
->head
, count
,
142 line
->driver
->write_irq
);
147 * We have flushed from ->head to buffer end, now we
148 * must flush only from the beginning to ->tail.
150 line
->head
= line
->buffer
;
157 count
= line
->tail
- line
->head
;
158 n
= write_chan(line
->chan_out
, line
->head
, count
,
159 line
->driver
->write_irq
);
165 return line
->head
== line
->tail
;
168 void line_flush_buffer(struct tty_struct
*tty
)
170 struct line
*line
= tty
->driver_data
;
173 spin_lock_irqsave(&line
->lock
, flags
);
175 spin_unlock_irqrestore(&line
->lock
, flags
);
179 * We map both ->flush_chars and ->put_char (which go in pair) onto
180 * ->flush_buffer and ->write. Hope it's not that bad.
182 void line_flush_chars(struct tty_struct
*tty
)
184 line_flush_buffer(tty
);
187 int line_write(struct tty_struct
*tty
, const unsigned char *buf
, int len
)
189 struct line
*line
= tty
->driver_data
;
193 spin_lock_irqsave(&line
->lock
, flags
);
194 if (line
->head
!= line
->tail
)
195 ret
= buffer_data(line
, buf
, len
);
197 n
= write_chan(line
->chan_out
, buf
, len
,
198 line
->driver
->write_irq
);
207 ret
+= buffer_data(line
, buf
+ n
, len
);
210 spin_unlock_irqrestore(&line
->lock
, flags
);
214 void line_throttle(struct tty_struct
*tty
)
216 struct line
*line
= tty
->driver_data
;
218 deactivate_chan(line
->chan_in
, line
->driver
->read_irq
);
222 void line_unthrottle(struct tty_struct
*tty
)
224 struct line
*line
= tty
->driver_data
;
227 chan_interrupt(line
, line
->driver
->read_irq
);
230 static irqreturn_t
line_write_interrupt(int irq
, void *data
)
232 struct chan
*chan
= data
;
233 struct line
*line
= chan
->line
;
237 * Interrupts are disabled here because genirq keep irqs disabled when
238 * calling the action handler.
241 spin_lock(&line
->lock
);
242 err
= flush_buffer(line
);
244 spin_unlock(&line
->lock
);
246 } else if ((err
< 0) && (err
!= -EAGAIN
)) {
247 line
->head
= line
->buffer
;
248 line
->tail
= line
->buffer
;
250 spin_unlock(&line
->lock
);
252 tty_port_tty_wakeup(&line
->port
);
257 int line_setup_irq(int fd
, int input
, int output
, struct line
*line
, void *data
)
259 const struct line_driver
*driver
= line
->driver
;
263 err
= um_request_irq(driver
->read_irq
, fd
, IRQ_READ
,
264 line_interrupt
, IRQF_SHARED
,
265 driver
->read_irq_name
, data
);
271 err
= um_request_irq(driver
->write_irq
, fd
, IRQ_WRITE
,
272 line_write_interrupt
, IRQF_SHARED
,
273 driver
->write_irq_name
, data
);
281 static int line_activate(struct tty_port
*port
, struct tty_struct
*tty
)
284 struct line
*line
= tty
->driver_data
;
286 ret
= enable_chan(line
);
291 chan_enable_winch(line
->chan_out
, port
);
295 chan_window_size(line
, &tty
->winsize
.ws_row
,
296 &tty
->winsize
.ws_col
);
301 static void unregister_winch(struct tty_struct
*tty
);
303 static void line_destruct(struct tty_port
*port
)
305 struct tty_struct
*tty
= tty_port_tty_get(port
);
306 struct line
*line
= tty
->driver_data
;
309 unregister_winch(tty
);
314 static const struct tty_port_operations line_port_ops
= {
315 .activate
= line_activate
,
316 .destruct
= line_destruct
,
319 int line_open(struct tty_struct
*tty
, struct file
*filp
)
321 struct line
*line
= tty
->driver_data
;
323 return tty_port_open(&line
->port
, tty
, filp
);
326 int line_install(struct tty_driver
*driver
, struct tty_struct
*tty
,
331 ret
= tty_standard_install(driver
, tty
);
335 tty
->driver_data
= line
;
340 void line_close(struct tty_struct
*tty
, struct file
* filp
)
342 struct line
*line
= tty
->driver_data
;
344 tty_port_close(&line
->port
, tty
, filp
);
347 void line_hangup(struct tty_struct
*tty
)
349 struct line
*line
= tty
->driver_data
;
351 tty_port_hangup(&line
->port
);
354 void close_lines(struct line
*lines
, int nlines
)
358 for(i
= 0; i
< nlines
; i
++)
359 close_chan(&lines
[i
]);
362 int setup_one_line(struct line
*lines
, int n
, char *init
,
363 const struct chan_opts
*opts
, char **error_out
)
365 struct line
*line
= &lines
[n
];
366 struct tty_driver
*driver
= line
->driver
->driver
;
369 if (line
->port
.count
) {
370 *error_out
= "Device is already open";
374 if (!strcmp(init
, "none")) {
377 kfree(line
->init_str
);
378 tty_unregister_device(driver
, n
);
379 parse_chan_pair(NULL
, line
, n
, opts
, error_out
);
383 char *new = kstrdup(init
, GFP_KERNEL
);
385 *error_out
= "Failed to allocate memory";
389 tty_unregister_device(driver
, n
);
390 kfree(line
->init_str
);
392 line
->init_str
= new;
394 err
= parse_chan_pair(new, line
, n
, opts
, error_out
);
396 struct device
*d
= tty_port_register_device(&line
->port
,
399 *error_out
= "Failed to register device";
401 parse_chan_pair(NULL
, line
, n
, opts
, error_out
);
405 line
->init_str
= NULL
;
415 * Common setup code for both startup command line and mconsole initialization.
416 * @lines contains the array (of size @num) to modify;
417 * @init is the setup string;
418 * @error_out is an error string in the case of failure;
421 int line_setup(char **conf
, unsigned int num
, char **def
,
422 char *init
, char *name
)
428 * We said con=/ssl= instead of con#=, so we are configuring all
434 unsigned n
= simple_strtoul(init
, &end
, 0);
437 error
= "Couldn't parse device number";
441 error
= "Device number out of range";
449 printk(KERN_ERR
"Failed to set up %s with "
450 "configuration string \"%s\" : %s\n", name
, init
, error
);
454 int line_config(struct line
*lines
, unsigned int num
, char *str
,
455 const struct chan_opts
*opts
, char **error_out
)
461 *error_out
= "Can't configure all devices from mconsole";
465 n
= simple_strtoul(str
, &end
, 0);
467 *error_out
= "Couldn't parse device number";
471 *error_out
= "Device number out of range";
475 return setup_one_line(lines
, n
, end
, opts
, error_out
);
478 int line_get_config(char *name
, struct line
*lines
, unsigned int num
, char *str
,
479 int size
, char **error_out
)
485 dev
= simple_strtoul(name
, &end
, 0);
486 if ((*end
!= '\0') || (end
== name
)) {
487 *error_out
= "line_get_config failed to parse device number";
491 if ((dev
< 0) || (dev
>= num
)) {
492 *error_out
= "device number out of range";
499 CONFIG_CHUNK(str
, size
, n
, "none", 1);
501 struct tty_struct
*tty
= tty_port_tty_get(&line
->port
);
503 CONFIG_CHUNK(str
, size
, n
, line
->init_str
, 1);
505 n
= chan_config_string(line
, str
, size
, error_out
);
513 int line_id(char **str
, int *start_out
, int *end_out
)
518 n
= simple_strtoul(*str
, &end
, 0);
519 if ((*end
!= '\0') || (end
== *str
))
528 int line_remove(struct line
*lines
, unsigned int num
, int n
, char **error_out
)
531 *error_out
= "Device number out of range";
534 return setup_one_line(lines
, n
, "none", NULL
, error_out
);
537 int register_lines(struct line_driver
*line_driver
,
538 const struct tty_operations
*ops
,
539 struct line
*lines
, int nlines
)
541 struct tty_driver
*driver
;
545 driver
= tty_alloc_driver(nlines
, TTY_DRIVER_REAL_RAW
|
546 TTY_DRIVER_DYNAMIC_DEV
);
548 return PTR_ERR(driver
);
550 driver
->driver_name
= line_driver
->name
;
551 driver
->name
= line_driver
->device_name
;
552 driver
->major
= line_driver
->major
;
553 driver
->minor_start
= line_driver
->minor_start
;
554 driver
->type
= line_driver
->type
;
555 driver
->subtype
= line_driver
->subtype
;
556 driver
->init_termios
= tty_std_termios
;
558 for (i
= 0; i
< nlines
; i
++) {
559 tty_port_init(&lines
[i
].port
);
560 lines
[i
].port
.ops
= &line_port_ops
;
561 spin_lock_init(&lines
[i
].lock
);
562 lines
[i
].driver
= line_driver
;
563 INIT_LIST_HEAD(&lines
[i
].chan_list
);
565 tty_set_operations(driver
, ops
);
567 err
= tty_register_driver(driver
);
569 printk(KERN_ERR
"register_lines : can't register %s driver\n",
571 tty_driver_kref_put(driver
);
572 for (i
= 0; i
< nlines
; i
++)
573 tty_port_destroy(&lines
[i
].port
);
577 line_driver
->driver
= driver
;
578 mconsole_register_dev(&line_driver
->mc
);
582 static DEFINE_SPINLOCK(winch_handler_lock
);
583 static LIST_HEAD(winch_handlers
);
586 struct list_head list
;
590 struct tty_port
*port
;
592 struct work_struct work
;
595 static void __free_winch(struct work_struct
*work
)
597 struct winch
*winch
= container_of(work
, struct winch
, work
);
598 um_free_irq(WINCH_IRQ
, winch
);
600 if (winch
->pid
!= -1)
601 os_kill_process(winch
->pid
, 1);
602 if (winch
->stack
!= 0)
603 free_stack(winch
->stack
, 0);
607 static void free_winch(struct winch
*winch
)
613 __free_winch(&winch
->work
);
616 static irqreturn_t
winch_interrupt(int irq
, void *data
)
618 struct winch
*winch
= data
;
619 struct tty_struct
*tty
;
627 err
= generic_read(fd
, &c
, NULL
);
629 if (err
!= -EAGAIN
) {
631 list_del(&winch
->list
);
633 printk(KERN_ERR
"winch_interrupt : "
634 "read failed, errno = %d\n", -err
);
635 printk(KERN_ERR
"fd %d is losing SIGWINCH "
636 "support\n", winch
->tty_fd
);
637 INIT_WORK(&winch
->work
, __free_winch
);
638 schedule_work(&winch
->work
);
644 tty
= tty_port_tty_get(winch
->port
);
646 line
= tty
->driver_data
;
648 chan_window_size(line
, &tty
->winsize
.ws_row
,
649 &tty
->winsize
.ws_col
);
650 pgrp
= tty_get_pgrp(tty
);
652 kill_pgrp(pgrp
, SIGWINCH
, 1);
661 void register_winch_irq(int fd
, int tty_fd
, int pid
, struct tty_port
*port
,
666 winch
= kmalloc(sizeof(*winch
), GFP_KERNEL
);
668 printk(KERN_ERR
"register_winch_irq - kmalloc failed\n");
672 *winch
= ((struct winch
) { .list
= LIST_HEAD_INIT(winch
->list
),
679 if (um_request_irq(WINCH_IRQ
, fd
, IRQ_READ
, winch_interrupt
,
680 IRQF_SHARED
, "winch", winch
) < 0) {
681 printk(KERN_ERR
"register_winch_irq - failed to register "
686 spin_lock(&winch_handler_lock
);
687 list_add(&winch
->list
, &winch_handlers
);
688 spin_unlock(&winch_handler_lock
);
695 os_kill_process(pid
, 1);
698 free_stack(stack
, 0);
701 static void unregister_winch(struct tty_struct
*tty
)
703 struct list_head
*ele
, *next
;
705 struct tty_struct
*wtty
;
707 spin_lock(&winch_handler_lock
);
709 list_for_each_safe(ele
, next
, &winch_handlers
) {
710 winch
= list_entry(ele
, struct winch
, list
);
711 wtty
= tty_port_tty_get(winch
->port
);
713 list_del(&winch
->list
);
714 spin_unlock(&winch_handler_lock
);
720 spin_unlock(&winch_handler_lock
);
723 static void winch_cleanup(void)
727 spin_lock(&winch_handler_lock
);
728 while ((winch
= list_first_entry_or_null(&winch_handlers
,
729 struct winch
, list
))) {
730 list_del(&winch
->list
);
731 spin_unlock(&winch_handler_lock
);
735 spin_lock(&winch_handler_lock
);
738 spin_unlock(&winch_handler_lock
);
740 __uml_exitcall(winch_cleanup
);
742 char *add_xterm_umid(char *base
)
751 len
= strlen(base
) + strlen(" ()") + strlen(umid
) + 1;
752 title
= kmalloc(len
, GFP_KERNEL
);
754 printk(KERN_ERR
"Failed to allocate buffer for xterm title\n");
758 snprintf(title
, len
, "%s (%s)", base
, umid
);