2 * drivers/s390/char/sclp_vt220.c
3 * SCLP VT220 terminal driver.
6 * Copyright IBM Corp. 2003,2008
7 * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
10 #include <linux/module.h>
11 #include <linux/spinlock.h>
12 #include <linux/list.h>
13 #include <linux/wait.h>
14 #include <linux/timer.h>
15 #include <linux/kernel.h>
16 #include <linux/tty.h>
17 #include <linux/tty_driver.h>
18 #include <linux/tty_flip.h>
19 #include <linux/errno.h>
21 #include <linux/major.h>
22 #include <linux/console.h>
23 #include <linux/kdev_t.h>
24 #include <linux/bootmem.h>
25 #include <linux/interrupt.h>
26 #include <linux/init.h>
27 #include <asm/uaccess.h>
30 #define SCLP_VT220_PRINT_HEADER "sclp vt220 tty driver: "
31 #define SCLP_VT220_MAJOR TTY_MAJOR
32 #define SCLP_VT220_MINOR 65
33 #define SCLP_VT220_DRIVER_NAME "sclp_vt220"
34 #define SCLP_VT220_DEVICE_NAME "ttysclp"
35 #define SCLP_VT220_CONSOLE_NAME "ttyS"
36 #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */
37 #define SCLP_VT220_BUF_SIZE 80
39 /* Representation of a single write request */
40 struct sclp_vt220_request
{
41 struct list_head list
;
42 struct sclp_req sclp_req
;
47 struct sclp_vt220_sccb
{
48 struct sccb_header header
;
49 struct evbuf_header evbuf
;
52 #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \
53 sizeof(struct sclp_vt220_request) - \
54 sizeof(struct sclp_vt220_sccb))
56 /* Structures and data needed to register tty driver */
57 static struct tty_driver
*sclp_vt220_driver
;
59 /* The tty_struct that the kernel associated with us */
60 static struct tty_struct
*sclp_vt220_tty
;
62 /* Lock to protect internal data from concurrent access */
63 static spinlock_t sclp_vt220_lock
;
65 /* List of empty pages to be used as write request buffers */
66 static struct list_head sclp_vt220_empty
;
68 /* List of pending requests */
69 static struct list_head sclp_vt220_outqueue
;
71 /* Number of requests in outqueue */
72 static int sclp_vt220_outqueue_count
;
74 /* Timer used for delaying write requests to merge subsequent messages into
76 static struct timer_list sclp_vt220_timer
;
78 /* Pointer to current request buffer which has been partially filled but not
80 static struct sclp_vt220_request
*sclp_vt220_current_request
;
82 /* Number of characters in current request buffer */
83 static int sclp_vt220_buffered_chars
;
85 /* Flag indicating whether this driver has already been initialized */
86 static int sclp_vt220_initialized
= 0;
88 /* Flag indicating that sclp_vt220_current_request should really
89 * have been already queued but wasn't because the SCLP was processing
91 static int sclp_vt220_flush_later
;
93 static void sclp_vt220_receiver_fn(struct evbuf_header
*evbuf
);
94 static int __sclp_vt220_emit(struct sclp_vt220_request
*request
);
95 static void sclp_vt220_emit_current(void);
97 /* Registration structure for our interest in SCLP event buffers */
98 static struct sclp_register sclp_vt220_register
= {
99 .send_mask
= EVTYP_VT220MSG_MASK
,
100 .receive_mask
= EVTYP_VT220MSG_MASK
,
101 .state_change_fn
= NULL
,
102 .receiver_fn
= sclp_vt220_receiver_fn
107 * Put provided request buffer back into queue and check emit pending
108 * buffers if necessary.
111 sclp_vt220_process_queue(struct sclp_vt220_request
*request
)
117 /* Put buffer back to list of empty buffers */
118 page
= request
->sclp_req
.sccb
;
119 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
120 /* Move request from outqueue to empty queue */
121 list_del(&request
->list
);
122 sclp_vt220_outqueue_count
--;
123 list_add_tail((struct list_head
*) page
, &sclp_vt220_empty
);
124 /* Check if there is a pending buffer on the out queue. */
126 if (!list_empty(&sclp_vt220_outqueue
))
127 request
= list_entry(sclp_vt220_outqueue
.next
,
128 struct sclp_vt220_request
, list
);
129 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
130 } while (request
&& __sclp_vt220_emit(request
));
131 if (request
== NULL
&& sclp_vt220_flush_later
)
132 sclp_vt220_emit_current();
133 /* Check if the tty needs a wake up call */
134 if (sclp_vt220_tty
!= NULL
) {
135 tty_wakeup(sclp_vt220_tty
);
139 #define SCLP_BUFFER_MAX_RETRY 1
142 * Callback through which the result of a write request is reported by the
146 sclp_vt220_callback(struct sclp_req
*request
, void *data
)
148 struct sclp_vt220_request
*vt220_request
;
149 struct sclp_vt220_sccb
*sccb
;
151 vt220_request
= (struct sclp_vt220_request
*) data
;
152 if (request
->status
== SCLP_REQ_FAILED
) {
153 sclp_vt220_process_queue(vt220_request
);
156 sccb
= (struct sclp_vt220_sccb
*) vt220_request
->sclp_req
.sccb
;
158 /* Check SCLP response code and choose suitable action */
159 switch (sccb
->header
.response_code
) {
163 case 0x05f0: /* Target resource in improper state */
166 case 0x0340: /* Contained SCLP equipment check */
167 if (++vt220_request
->retry_count
> SCLP_BUFFER_MAX_RETRY
)
169 /* Remove processed buffers and requeue rest */
170 if (sclp_remove_processed((struct sccb_header
*) sccb
) > 0) {
171 /* Not all buffers were processed */
172 sccb
->header
.response_code
= 0x0000;
173 vt220_request
->sclp_req
.status
= SCLP_REQ_FILLED
;
174 if (sclp_add_request(request
) == 0)
179 case 0x0040: /* SCLP equipment check */
180 if (++vt220_request
->retry_count
> SCLP_BUFFER_MAX_RETRY
)
182 sccb
->header
.response_code
= 0x0000;
183 vt220_request
->sclp_req
.status
= SCLP_REQ_FILLED
;
184 if (sclp_add_request(request
) == 0)
191 sclp_vt220_process_queue(vt220_request
);
195 * Emit vt220 request buffer to SCLP. Return zero on success, non-zero
199 __sclp_vt220_emit(struct sclp_vt220_request
*request
)
201 if (!(sclp_vt220_register
.sclp_receive_mask
& EVTYP_VT220MSG_MASK
)) {
202 request
->sclp_req
.status
= SCLP_REQ_FAILED
;
205 request
->sclp_req
.command
= SCLP_CMDW_WRITE_EVENT_DATA
;
206 request
->sclp_req
.status
= SCLP_REQ_FILLED
;
207 request
->sclp_req
.callback
= sclp_vt220_callback
;
208 request
->sclp_req
.callback_data
= (void *) request
;
210 return sclp_add_request(&request
->sclp_req
);
214 * Queue and emit given request.
217 sclp_vt220_emit(struct sclp_vt220_request
*request
)
222 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
223 list_add_tail(&request
->list
, &sclp_vt220_outqueue
);
224 count
= sclp_vt220_outqueue_count
++;
225 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
226 /* Emit only the first buffer immediately - callback takes care of
228 if (count
== 0 && __sclp_vt220_emit(request
))
229 sclp_vt220_process_queue(request
);
233 * Queue and emit current request. Return zero on success, non-zero otherwise.
236 sclp_vt220_emit_current(void)
239 struct sclp_vt220_request
*request
;
240 struct sclp_vt220_sccb
*sccb
;
242 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
244 if (sclp_vt220_current_request
!= NULL
) {
245 sccb
= (struct sclp_vt220_sccb
*)
246 sclp_vt220_current_request
->sclp_req
.sccb
;
247 /* Only emit buffers with content */
248 if (sccb
->header
.length
!= sizeof(struct sclp_vt220_sccb
)) {
249 request
= sclp_vt220_current_request
;
250 sclp_vt220_current_request
= NULL
;
251 if (timer_pending(&sclp_vt220_timer
))
252 del_timer(&sclp_vt220_timer
);
254 sclp_vt220_flush_later
= 0;
256 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
258 sclp_vt220_emit(request
);
261 #define SCLP_NORMAL_WRITE 0x00
264 * Helper function to initialize a page with the sclp request structure.
266 static struct sclp_vt220_request
*
267 sclp_vt220_initialize_page(void *page
)
269 struct sclp_vt220_request
*request
;
270 struct sclp_vt220_sccb
*sccb
;
272 /* Place request structure at end of page */
273 request
= ((struct sclp_vt220_request
*)
274 ((addr_t
) page
+ PAGE_SIZE
)) - 1;
275 request
->retry_count
= 0;
276 request
->sclp_req
.sccb
= page
;
277 /* SCCB goes at start of page */
278 sccb
= (struct sclp_vt220_sccb
*) page
;
279 memset((void *) sccb
, 0, sizeof(struct sclp_vt220_sccb
));
280 sccb
->header
.length
= sizeof(struct sclp_vt220_sccb
);
281 sccb
->header
.function_code
= SCLP_NORMAL_WRITE
;
282 sccb
->header
.response_code
= 0x0000;
283 sccb
->evbuf
.type
= EVTYP_VT220MSG
;
284 sccb
->evbuf
.length
= sizeof(struct evbuf_header
);
289 static inline unsigned int
290 sclp_vt220_space_left(struct sclp_vt220_request
*request
)
292 struct sclp_vt220_sccb
*sccb
;
293 sccb
= (struct sclp_vt220_sccb
*) request
->sclp_req
.sccb
;
294 return PAGE_SIZE
- sizeof(struct sclp_vt220_request
) -
298 static inline unsigned int
299 sclp_vt220_chars_stored(struct sclp_vt220_request
*request
)
301 struct sclp_vt220_sccb
*sccb
;
302 sccb
= (struct sclp_vt220_sccb
*) request
->sclp_req
.sccb
;
303 return sccb
->evbuf
.length
- sizeof(struct evbuf_header
);
307 * Add msg to buffer associated with request. Return the number of characters
311 sclp_vt220_add_msg(struct sclp_vt220_request
*request
,
312 const unsigned char *msg
, int count
, int convertlf
)
314 struct sclp_vt220_sccb
*sccb
;
320 if (count
> sclp_vt220_space_left(request
))
321 count
= sclp_vt220_space_left(request
);
325 sccb
= (struct sclp_vt220_sccb
*) request
->sclp_req
.sccb
;
326 buffer
= (void *) ((addr_t
) sccb
+ sccb
->header
.length
);
329 /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/
331 (from
< count
) && (to
< sclp_vt220_space_left(request
));
333 /* Retrieve character */
335 /* Perform conversion */
337 if (to
+ 1 < sclp_vt220_space_left(request
)) {
338 ((unsigned char *) buffer
)[to
++] = c
;
339 ((unsigned char *) buffer
)[to
++] = 0x0d;
344 ((unsigned char *) buffer
)[to
++] = c
;
346 sccb
->header
.length
+= to
;
347 sccb
->evbuf
.length
+= to
;
350 memcpy(buffer
, (const void *) msg
, count
);
351 sccb
->header
.length
+= count
;
352 sccb
->evbuf
.length
+= count
;
358 * Emit buffer after having waited long enough for more data to arrive.
361 sclp_vt220_timeout(unsigned long data
)
363 sclp_vt220_emit_current();
366 #define BUFFER_MAX_DELAY HZ/20
369 * Internal implementation of the write function. Write COUNT bytes of data
371 * to the SCLP interface. In case that the data does not fit into the current
372 * write buffer, emit the current one and allocate a new one. If there are no
373 * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE
374 * is non-zero, the buffer will be scheduled for emitting after a timeout -
375 * otherwise the user has to explicitly call the flush function.
376 * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message
377 * buffer should be converted to 0x0a 0x0d. After completion, return the number
381 __sclp_vt220_write(const unsigned char *buf
, int count
, int do_schedule
,
382 int convertlf
, int may_fail
)
392 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
394 /* Create an sclp output buffer if none exists yet */
395 if (sclp_vt220_current_request
== NULL
) {
396 while (list_empty(&sclp_vt220_empty
)) {
397 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
402 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
404 page
= (void *) sclp_vt220_empty
.next
;
405 list_del((struct list_head
*) page
);
406 sclp_vt220_current_request
=
407 sclp_vt220_initialize_page(page
);
409 /* Try to write the string to the current request buffer */
410 written
= sclp_vt220_add_msg(sclp_vt220_current_request
,
411 buf
, count
, convertlf
);
412 overall_written
+= written
;
413 if (written
== count
)
416 * Not all characters could be written to the current
417 * output buffer. Emit the buffer, create a new buffer
418 * and then output the rest of the string.
420 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
421 sclp_vt220_emit_current();
422 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
426 /* Setup timer to output current console buffer after some time */
427 if (sclp_vt220_current_request
!= NULL
&&
428 !timer_pending(&sclp_vt220_timer
) && do_schedule
) {
429 sclp_vt220_timer
.function
= sclp_vt220_timeout
;
430 sclp_vt220_timer
.data
= 0UL;
431 sclp_vt220_timer
.expires
= jiffies
+ BUFFER_MAX_DELAY
;
432 add_timer(&sclp_vt220_timer
);
434 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
436 return overall_written
;
440 * This routine is called by the kernel to write a series of
441 * characters to the tty device. The characters may come from
442 * user space or kernel space. This routine will return the
443 * number of characters actually accepted for writing.
446 sclp_vt220_write(struct tty_struct
*tty
, const unsigned char *buf
, int count
)
448 return __sclp_vt220_write(buf
, count
, 1, 0, 1);
451 #define SCLP_VT220_SESSION_ENDED 0x01
452 #define SCLP_VT220_SESSION_STARTED 0x80
453 #define SCLP_VT220_SESSION_DATA 0x00
456 * Called by the SCLP to report incoming event buffers.
459 sclp_vt220_receiver_fn(struct evbuf_header
*evbuf
)
464 /* Ignore input if device is not open */
465 if (sclp_vt220_tty
== NULL
)
468 buffer
= (char *) ((addr_t
) evbuf
+ sizeof(struct evbuf_header
));
469 count
= evbuf
->length
- sizeof(struct evbuf_header
);
472 case SCLP_VT220_SESSION_ENDED
:
473 case SCLP_VT220_SESSION_STARTED
:
475 case SCLP_VT220_SESSION_DATA
:
476 /* Send input to line discipline */
479 tty_insert_flip_string(sclp_vt220_tty
, buffer
, count
);
480 tty_flip_buffer_push(sclp_vt220_tty
);
486 * This routine is called when a particular tty device is opened.
489 sclp_vt220_open(struct tty_struct
*tty
, struct file
*filp
)
491 if (tty
->count
== 1) {
492 sclp_vt220_tty
= tty
;
493 tty
->driver_data
= kmalloc(SCLP_VT220_BUF_SIZE
, GFP_KERNEL
);
494 if (tty
->driver_data
== NULL
)
496 tty
->low_latency
= 0;
502 * This routine is called when a particular tty device is closed.
505 sclp_vt220_close(struct tty_struct
*tty
, struct file
*filp
)
507 if (tty
->count
== 1) {
508 sclp_vt220_tty
= NULL
;
509 kfree(tty
->driver_data
);
510 tty
->driver_data
= NULL
;
515 * This routine is called by the kernel to write a single
516 * character to the tty device. If the kernel uses this routine,
517 * it must call the flush_chars() routine (if defined) when it is
518 * done stuffing characters into the driver.
521 sclp_vt220_put_char(struct tty_struct
*tty
, unsigned char ch
)
523 return __sclp_vt220_write(&ch
, 1, 0, 0, 1);
527 * This routine is called by the kernel after it has written a
528 * series of characters to the tty device using put_char().
531 sclp_vt220_flush_chars(struct tty_struct
*tty
)
533 if (sclp_vt220_outqueue_count
== 0)
534 sclp_vt220_emit_current();
536 sclp_vt220_flush_later
= 1;
540 * This routine returns the numbers of characters the tty driver
541 * will accept for queuing to be written. This number is subject
542 * to change as output buffers get emptied, or if the output flow
546 sclp_vt220_write_room(struct tty_struct
*tty
)
552 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
554 if (sclp_vt220_current_request
!= NULL
)
555 count
= sclp_vt220_space_left(sclp_vt220_current_request
);
556 list_for_each(l
, &sclp_vt220_empty
)
557 count
+= SCLP_VT220_MAX_CHARS_PER_BUFFER
;
558 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
563 * Return number of buffered chars.
566 sclp_vt220_chars_in_buffer(struct tty_struct
*tty
)
570 struct sclp_vt220_request
*r
;
573 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
575 if (sclp_vt220_current_request
!= NULL
)
576 count
= sclp_vt220_chars_stored(sclp_vt220_current_request
);
577 list_for_each(l
, &sclp_vt220_outqueue
) {
578 r
= list_entry(l
, struct sclp_vt220_request
, list
);
579 count
+= sclp_vt220_chars_stored(r
);
581 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
586 __sclp_vt220_flush_buffer(void)
590 sclp_vt220_emit_current();
591 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
592 if (timer_pending(&sclp_vt220_timer
))
593 del_timer(&sclp_vt220_timer
);
594 while (sclp_vt220_outqueue_count
> 0) {
595 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
597 spin_lock_irqsave(&sclp_vt220_lock
, flags
);
599 spin_unlock_irqrestore(&sclp_vt220_lock
, flags
);
603 * Pass on all buffers to the hardware. Return only when there are no more
607 sclp_vt220_flush_buffer(struct tty_struct
*tty
)
609 sclp_vt220_emit_current();
613 * Initialize all relevant components and register driver with system.
615 static void __init
__sclp_vt220_cleanup(void)
617 struct list_head
*page
, *p
;
619 list_for_each_safe(page
, p
, &sclp_vt220_empty
) {
621 if (slab_is_available())
622 free_page((unsigned long) page
);
624 free_bootmem((unsigned long) page
, PAGE_SIZE
);
626 if (!list_empty(&sclp_vt220_register
.list
))
627 sclp_unregister(&sclp_vt220_register
);
628 sclp_vt220_initialized
= 0;
631 static int __init
__sclp_vt220_init(void)
638 if (sclp_vt220_initialized
)
640 sclp_vt220_initialized
= 1;
641 spin_lock_init(&sclp_vt220_lock
);
642 INIT_LIST_HEAD(&sclp_vt220_empty
);
643 INIT_LIST_HEAD(&sclp_vt220_outqueue
);
644 init_timer(&sclp_vt220_timer
);
645 sclp_vt220_current_request
= NULL
;
646 sclp_vt220_buffered_chars
= 0;
647 sclp_vt220_outqueue_count
= 0;
648 sclp_vt220_tty
= NULL
;
649 sclp_vt220_flush_later
= 0;
651 /* Allocate pages for output buffering */
652 num_pages
= slab_is_available() ? MAX_KMEM_PAGES
: MAX_CONSOLE_PAGES
;
653 for (i
= 0; i
< num_pages
; i
++) {
654 if (slab_is_available())
655 page
= (void *) get_zeroed_page(GFP_KERNEL
| GFP_DMA
);
657 page
= alloc_bootmem_low_pages(PAGE_SIZE
);
659 __sclp_vt220_cleanup();
662 list_add_tail((struct list_head
*) page
, &sclp_vt220_empty
);
664 rc
= sclp_register(&sclp_vt220_register
);
666 printk(KERN_ERR SCLP_VT220_PRINT_HEADER
667 "could not register vt220 - "
668 "sclp_register returned %d\n", rc
);
669 __sclp_vt220_cleanup();
674 static const struct tty_operations sclp_vt220_ops
= {
675 .open
= sclp_vt220_open
,
676 .close
= sclp_vt220_close
,
677 .write
= sclp_vt220_write
,
678 .put_char
= sclp_vt220_put_char
,
679 .flush_chars
= sclp_vt220_flush_chars
,
680 .write_room
= sclp_vt220_write_room
,
681 .chars_in_buffer
= sclp_vt220_chars_in_buffer
,
682 .flush_buffer
= sclp_vt220_flush_buffer
,
686 * Register driver with SCLP and Linux and initialize internal tty structures.
688 static int __init
sclp_vt220_tty_init(void)
690 struct tty_driver
*driver
;
694 /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve
695 * symmetry between VM and LPAR systems regarding ttyS1. */
696 driver
= alloc_tty_driver(1);
699 cleanup
= !sclp_vt220_initialized
;
700 rc
= __sclp_vt220_init();
704 driver
->owner
= THIS_MODULE
;
705 driver
->driver_name
= SCLP_VT220_DRIVER_NAME
;
706 driver
->name
= SCLP_VT220_DEVICE_NAME
;
707 driver
->major
= SCLP_VT220_MAJOR
;
708 driver
->minor_start
= SCLP_VT220_MINOR
;
709 driver
->type
= TTY_DRIVER_TYPE_SYSTEM
;
710 driver
->subtype
= SYSTEM_TYPE_TTY
;
711 driver
->init_termios
= tty_std_termios
;
712 driver
->flags
= TTY_DRIVER_REAL_RAW
;
713 tty_set_operations(driver
, &sclp_vt220_ops
);
715 rc
= tty_register_driver(driver
);
717 printk(KERN_ERR SCLP_VT220_PRINT_HEADER
718 "could not register tty - "
719 "tty_register_driver returned %d\n", rc
);
722 sclp_vt220_driver
= driver
;
727 __sclp_vt220_cleanup();
729 put_tty_driver(driver
);
732 __initcall(sclp_vt220_tty_init
);
734 #ifdef CONFIG_SCLP_VT220_CONSOLE
737 sclp_vt220_con_write(struct console
*con
, const char *buf
, unsigned int count
)
739 __sclp_vt220_write((const unsigned char *) buf
, count
, 1, 1, 0);
742 static struct tty_driver
*
743 sclp_vt220_con_device(struct console
*c
, int *index
)
746 return sclp_vt220_driver
;
750 * This routine is called from panic when the kernel is going to give up.
751 * We have to make sure that all buffers will be flushed to the SCLP.
752 * Note that this function may be called from within an interrupt context.
755 sclp_vt220_con_unblank(void)
757 __sclp_vt220_flush_buffer();
760 /* Structure needed to register with printk */
761 static struct console sclp_vt220_console
=
763 .name
= SCLP_VT220_CONSOLE_NAME
,
764 .write
= sclp_vt220_con_write
,
765 .device
= sclp_vt220_con_device
,
766 .unblank
= sclp_vt220_con_unblank
,
767 .flags
= CON_PRINTBUFFER
,
768 .index
= SCLP_VT220_CONSOLE_INDEX
772 sclp_vt220_con_init(void)
776 INIT_LIST_HEAD(&sclp_vt220_register
.list
);
777 if (!CONSOLE_IS_SCLP
)
779 rc
= __sclp_vt220_init();
782 /* Attach linux console */
783 register_console(&sclp_vt220_console
);
787 console_initcall(sclp_vt220_con_init
);
788 #endif /* CONFIG_SCLP_VT220_CONSOLE */