1/* -*- linux-c -*-
2 *
3 *  drivers/char/viocons.c
4 *
5 *  iSeries Virtual Terminal
6 *
7 *  Authors: Dave Boutcher <boutcher@us.ibm.com>
8 *           Ryan Arnold <ryanarn@us.ibm.com>
9 *           Colin Devilbiss <devilbis@us.ibm.com>
10 *           Stephen Rothwell <sfr@au1.ibm.com>
11 *
12 * (C) Copyright 2000, 2001, 2002, 2003, 2004 IBM Corporation
13 *
14 * This program is free software;  you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) anyu later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22 * General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 */
28#include <linux/kernel.h>
29#include <linux/proc_fs.h>
30#include <linux/errno.h>
31#include <linux/vmalloc.h>
32#include <linux/mm.h>
33#include <linux/console.h>
34#include <linux/module.h>
35#include <asm/uaccess.h>
36#include <linux/init.h>
37#include <linux/wait.h>
38#include <linux/spinlock.h>
39#include <asm/ioctls.h>
40#include <linux/kd.h>
41#include <linux/tty.h>
42#include <linux/tty_flip.h>
43#include <linux/sysrq.h>
44
45#include <asm/firmware.h>
46#include <asm/iseries/vio.h>
47#include <asm/iseries/hv_lp_event.h>
48#include <asm/iseries/hv_call_event.h>
49#include <asm/iseries/hv_lp_config.h>
50#include <asm/iseries/hv_call.h>
51
52#ifdef CONFIG_VT
53#error You must turn off CONFIG_VT to use CONFIG_VIOCONS
54#endif
55
56#define VIOTTY_MAGIC (0x0DCB)
57#define VTTY_PORTS 10
58
59#define VIOCONS_KERN_WARN	KERN_WARNING "viocons: "
60#define VIOCONS_KERN_INFO	KERN_INFO "viocons: "
61
62static DEFINE_SPINLOCK(consolelock);
63static DEFINE_SPINLOCK(consoleloglock);
64
65static int vio_sysrq_pressed;
66
67#define VIOCHAR_NUM_BUF		16
68
69/*
70 * Our port information.  We store a pointer to one entry in the
71 * tty_driver_data
72 */
73static struct port_info {
74	int magic;
75	struct tty_struct *tty;
76	HvLpIndex lp;
77	u8 vcons;
78	u64 seq;	/* sequence number of last HV send */
79	u64 ack;	/* last ack from HV */
80/*
81 * When we get writes faster than we can send it to the partition,
82 * buffer the data here. Note that used is a bit map of used buffers.
83 * It had better have enough bits to hold VIOCHAR_NUM_BUF the bitops assume
84 * it is a multiple of unsigned long
85 */
86	unsigned long used;
87	u8 *buffer[VIOCHAR_NUM_BUF];
88	int bufferBytes[VIOCHAR_NUM_BUF];
89	int curbuf;
90	int bufferOverflow;
91	int overflowMessage;
92} port_info[VTTY_PORTS];
93
94#define viochar_is_console(pi)	((pi) == &port_info[0])
95#define viochar_port(pi)	((pi) - &port_info[0])
96
97static void initDataEvent(struct viocharlpevent *viochar, HvLpIndex lp);
98
99static struct tty_driver *viotty_driver;
100
101static void hvlog(char *fmt, ...)
102{
103	int i;
104	unsigned long flags;
105	va_list args;
106	static char buf[256];
107
108	spin_lock_irqsave(&consoleloglock, flags);
109	va_start(args, fmt);
110	i = vscnprintf(buf, sizeof(buf) - 1, fmt, args);
111	va_end(args);
112	buf[i++] = '\r';
113	HvCall_writeLogBuffer(buf, i);
114	spin_unlock_irqrestore(&consoleloglock, flags);
115}
116
117static void hvlogOutput(const char *buf, int count)
118{
119	unsigned long flags;
120	int begin;
121	int index;
122	static const char cr = '\r';
123
124	begin = 0;
125	spin_lock_irqsave(&consoleloglock, flags);
126	for (index = 0; index < count; index++) {
127		if (buf[index] == '\n') {
128			/*
129			 * Start right after the last '\n' or at the zeroth
130			 * array position and output the number of characters
131			 * including the newline.
132			 */
133			HvCall_writeLogBuffer(&buf[begin], index - begin + 1);
134			begin = index + 1;
135			HvCall_writeLogBuffer(&cr, 1);
136		}
137	}
138	if ((index - begin) > 0)
139		HvCall_writeLogBuffer(&buf[begin], index - begin);
140	spin_unlock_irqrestore(&consoleloglock, flags);
141}
142
143/*
144 * Make sure we're pointing to a valid port_info structure.  Shamelessly
145 * plagerized from serial.c
146 */
147static inline int viotty_paranoia_check(struct port_info *pi,
148					char *name, const char *routine)
149{
150	static const char *bad_pi_addr = VIOCONS_KERN_WARN
151		"warning: bad address for port_info struct (%s) in %s\n";
152	static const char *badmagic = VIOCONS_KERN_WARN
153		"warning: bad magic number for port_info struct (%s) in %s\n";
154
155	if ((pi < &port_info[0]) || (viochar_port(pi) > VTTY_PORTS)) {
156		printk(bad_pi_addr, name, routine);
157		return 1;
158	}
159	if (pi->magic != VIOTTY_MAGIC) {
160		printk(badmagic, name, routine);
161		return 1;
162	}
163	return 0;
164}
165
166/*
167 * Add data to our pending-send buffers.
168 *
169 * NOTE: Don't use printk in here because it gets nastily recursive.
170 * hvlog can be used to log to the hypervisor buffer
171 */
172static int buffer_add(struct port_info *pi, const char *buf, size_t len)
173{
174	size_t bleft;
175	size_t curlen;
176	const char *curbuf;
177	int nextbuf;
178
179	curbuf = buf;
180	bleft = len;
181	while (bleft > 0) {
182		/*
183		 * If there is no space left in the current buffer, we have
184		 * filled everything up, so return.  If we filled the previous
185		 * buffer we would already have moved to the next one.
186		 */
187		if (pi->bufferBytes[pi->curbuf] == VIOCHAR_MAX_DATA) {
188			hvlog ("\n\rviocons: No overflow buffer available for memcpy().\n");
189			pi->bufferOverflow++;
190			pi->overflowMessage = 1;
191			break;
192		}
193
194		/*
195		 * Turn on the "used" bit for this buffer.  If it's already on,
196		 * that's fine.
197		 */
198		set_bit(pi->curbuf, &pi->used);
199
200		/*
201		 * See if this buffer has been allocated.  If not, allocate it.
202		 */
203		if (pi->buffer[pi->curbuf] == NULL) {
204			pi->buffer[pi->curbuf] =
205			    kmalloc(VIOCHAR_MAX_DATA, GFP_ATOMIC);
206			if (pi->buffer[pi->curbuf] == NULL) {
207				hvlog("\n\rviocons: kmalloc failed allocating spaces for buffer %d.",
208					pi->curbuf);
209				break;
210			}
211		}
212
213		/* Figure out how much we can copy into this buffer. */
214		if (bleft < (VIOCHAR_MAX_DATA - pi->bufferBytes[pi->curbuf]))
215			curlen = bleft;
216		else
217			curlen = VIOCHAR_MAX_DATA - pi->bufferBytes[pi->curbuf];
218
219		/* Copy the data into the buffer. */
220		memcpy(pi->buffer[pi->curbuf] + pi->bufferBytes[pi->curbuf],
221				curbuf, curlen);
222
223		pi->bufferBytes[pi->curbuf] += curlen;
224		curbuf += curlen;
225		bleft -= curlen;
226
227		/*
228		 * Now see if we've filled this buffer.  If not then
229		 * we'll try to use it again later.  If we've filled it
230		 * up then we'll advance the curbuf to the next in the
231		 * circular queue.
232		 */
233		if (pi->bufferBytes[pi->curbuf] == VIOCHAR_MAX_DATA) {
234			nextbuf = (pi->curbuf + 1) % VIOCHAR_NUM_BUF;
235			/*
236			 * Move to the next buffer if it hasn't been used yet
237			 */
238			if (test_bit(nextbuf, &pi->used) == 0)
239				pi->curbuf = nextbuf;
240		}
241	}
242	return len - bleft;
243}
244
245/*
246 * Send pending data
247 *
248 * NOTE: Don't use printk in here because it gets nastily recursive.
249 * hvlog can be used to log to the hypervisor buffer
250 */
251static void send_buffers(struct port_info *pi)
252{
253	HvLpEvent_Rc hvrc;
254	int nextbuf;
255	struct viocharlpevent *viochar;
256	unsigned long flags;
257
258	spin_lock_irqsave(&consolelock, flags);
259
260	viochar = (struct viocharlpevent *)
261	    vio_get_event_buffer(viomajorsubtype_chario);
262
263	/* Make sure we got a buffer */
264	if (viochar == NULL) {
265		hvlog("\n\rviocons: Can't get viochar buffer in sendBuffers().");
266		spin_unlock_irqrestore(&consolelock, flags);
267		return;
268	}
269
270	if (pi->used == 0) {
271		hvlog("\n\rviocons: in sendbuffers(), but no buffers used.\n");
272		vio_free_event_buffer(viomajorsubtype_chario, viochar);
273		spin_unlock_irqrestore(&consolelock, flags);
274		return;
275	}
276
277	/*
278	 * curbuf points to the buffer we're filling.  We want to
279	 * start sending AFTER this one.
280	 */
281	nextbuf = (pi->curbuf + 1) % VIOCHAR_NUM_BUF;
282
283	/*
284	 * Loop until we find a buffer with the used bit on
285	 */
286	while (test_bit(nextbuf, &pi->used) == 0)
287		nextbuf = (nextbuf + 1) % VIOCHAR_NUM_BUF;
288
289	initDataEvent(viochar, pi->lp);
290
291	/*
292	 * While we have buffers with data, and our send window
293	 * is open, send them
294	 */
295	while ((test_bit(nextbuf, &pi->used)) &&
296	       ((pi->seq - pi->ack) < VIOCHAR_WINDOW)) {
297		viochar->len = pi->bufferBytes[nextbuf];
298		viochar->event.xCorrelationToken = pi->seq++;
299		viochar->event.xSizeMinus1 =
300			offsetof(struct viocharlpevent, data) + viochar->len;
301
302		memcpy(viochar->data, pi->buffer[nextbuf], viochar->len);
303
304		hvrc = HvCallEvent_signalLpEvent(&viochar->event);
305		if (hvrc) {
306			/*
307			 * MUST unlock the spinlock before doing a printk
308			 */
309			vio_free_event_buffer(viomajorsubtype_chario, viochar);
310			spin_unlock_irqrestore(&consolelock, flags);
311
312			printk(VIOCONS_KERN_WARN
313			       "error sending event! return code %d\n",
314			       (int)hvrc);
315			return;
316		}
317
318		/*
319		 * clear the used bit, zero the number of bytes in
320		 * this buffer, and move to the next buffer
321		 */
322		clear_bit(nextbuf, &pi->used);
323		pi->bufferBytes[nextbuf] = 0;
324		nextbuf = (nextbuf + 1) % VIOCHAR_NUM_BUF;
325	}
326
327	/*
328	 * If we have emptied all the buffers, start at 0 again.
329	 * this will re-use any allocated buffers
330	 */
331	if (pi->used == 0) {
332		pi->curbuf = 0;
333
334		if (pi->overflowMessage)
335			pi->overflowMessage = 0;
336
337		if (pi->tty) {
338			tty_wakeup(pi->tty);
339		}
340	}
341
342	vio_free_event_buffer(viomajorsubtype_chario, viochar);
343	spin_unlock_irqrestore(&consolelock, flags);
344}
345
346/*
347 * Our internal writer.  Gets called both from the console device and
348 * the tty device.  the tty pointer will be NULL if called from the console.
349 * Return total number of bytes "written".
350 *
351 * NOTE: Don't use printk in here because it gets nastily recursive.  hvlog
352 * can be used to log to the hypervisor buffer
353 */
354static int internal_write(struct port_info *pi, const char *buf, size_t len)
355{
356	HvLpEvent_Rc hvrc;
357	size_t bleft;
358	size_t curlen;
359	const char *curbuf;
360	unsigned long flags;
361	struct viocharlpevent *viochar;
362
363	/*
364	 * Write to the hvlog of inbound data are now done prior to
365	 * calling internal_write() since internal_write() is only called in
366	 * the event that an lp event path is active, which isn't the case for
367	 * logging attempts prior to console initialization.
368	 *
369	 * If there is already data queued for this port, send it prior to
370	 * attempting to send any new data.
371	 */
372	if (pi->used)
373		send_buffers(pi);
374
375	spin_lock_irqsave(&consolelock, flags);
376
377	viochar = vio_get_event_buffer(viomajorsubtype_chario);
378	if (viochar == NULL) {
379		spin_unlock_irqrestore(&consolelock, flags);
380		hvlog("\n\rviocons: Can't get vio buffer in internal_write().");
381		return -EAGAIN;
382	}
383	initDataEvent(viochar, pi->lp);
384
385	curbuf = buf;
386	bleft = len;
387
388	while ((bleft > 0) && (pi->used == 0) &&
389	       ((pi->seq - pi->ack) < VIOCHAR_WINDOW)) {
390		if (bleft > VIOCHAR_MAX_DATA)
391			curlen = VIOCHAR_MAX_DATA;
392		else
393			curlen = bleft;
394
395		viochar->event.xCorrelationToken = pi->seq++;
396		memcpy(viochar->data, curbuf, curlen);
397		viochar->len = curlen;
398		viochar->event.xSizeMinus1 =
399		    offsetof(struct viocharlpevent, data) + curlen;
400
401		hvrc = HvCallEvent_signalLpEvent(&viochar->event);
402		if (hvrc) {
403			hvlog("viocons: error sending event! %d\n", (int)hvrc);
404			goto out;
405		}
406		curbuf += curlen;
407		bleft -= curlen;
408	}
409
410	/* If we didn't send it all, buffer as much of it as we can. */
411	if (bleft > 0)
412		bleft -= buffer_add(pi, curbuf, bleft);
413out:
414	vio_free_event_buffer(viomajorsubtype_chario, viochar);
415	spin_unlock_irqrestore(&consolelock, flags);
416	return len - bleft;
417}
418
419static struct port_info *get_port_data(struct tty_struct *tty)
420{
421	unsigned long flags;
422	struct port_info *pi;
423
424	spin_lock_irqsave(&consolelock, flags);
425	if (tty) {
426		pi = (struct port_info *)tty->driver_data;
427		if (!pi || viotty_paranoia_check(pi, tty->name,
428					     "get_port_data")) {
429			pi = NULL;
430		}
431	} else
432		/*
433		 * If this is the console device, use the lp from
434		 * the first port entry
435		 */
436		pi = &port_info[0];
437	spin_unlock_irqrestore(&consolelock, flags);
438	return pi;
439}
440
441/*
442 * Initialize the common fields in a charLpEvent
443 */
444static void initDataEvent(struct viocharlpevent *viochar, HvLpIndex lp)
445{
446	struct HvLpEvent *hev = &viochar->event;
447
448	memset(viochar, 0, sizeof(struct viocharlpevent));
449
450	hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DEFERRED_ACK |
451		HV_LP_EVENT_INT;
452	hev->xType = HvLpEvent_Type_VirtualIo;
453	hev->xSubtype = viomajorsubtype_chario | viochardata;
454	hev->xSourceLp = HvLpConfig_getLpIndex();
455	hev->xTargetLp = lp;
456	hev->xSizeMinus1 = sizeof(struct viocharlpevent);
457	hev->xSourceInstanceId = viopath_sourceinst(lp);
458	hev->xTargetInstanceId = viopath_targetinst(lp);
459}
460
461/*
462 * early console device write
463 */
464static void viocons_write_early(struct console *co, const char *s, unsigned count)
465{
466	hvlogOutput(s, count);
467}
468
469/*
470 * console device write
471 */
472static void viocons_write(struct console *co, const char *s, unsigned count)
473{
474	int index;
475	int begin;
476	struct port_info *pi;
477
478	static const char cr = '\r';
479
480	/*
481	 * Check port data first because the target LP might be valid but
482	 * simply not active, in which case we want to hvlog the output.
483	 */
484	pi = get_port_data(NULL);
485	if (pi == NULL) {
486		hvlog("\n\rviocons_write: unable to get port data.");
487		return;
488	}
489
490	hvlogOutput(s, count);
491
492	if (!viopath_isactive(pi->lp))
493		return;
494
495	/*
496	 * Any newline character found will cause a
497	 * carriage return character to be emitted as well.
498	 */
499	begin = 0;
500	for (index = 0; index < count; index++) {
501		if (s[index] == '\n') {
502			/*
503			 * Newline found. Print everything up to and
504			 * including the newline
505			 */
506			internal_write(pi, &s[begin], index - begin + 1);
507			begin = index + 1;
508			/* Emit a carriage return as well */
509			internal_write(pi, &cr, 1);
510		}
511	}
512
513	/* If any characters left to write, write them now */
514	if ((index - begin) > 0)
515		internal_write(pi, &s[begin], index - begin);
516}
517
518/*
519 * Work out the device associate with this console
520 */
521static struct tty_driver *viocons_device(struct console *c, int *index)
522{
523	*index = c->index;
524	return viotty_driver;
525}
526
527/*
528 * console device I/O methods
529 */
530static struct console viocons_early = {
531	.name = "viocons",
532	.write = viocons_write_early,
533	.flags = CON_PRINTBUFFER,
534	.index = -1,
535};
536
537static struct console viocons = {
538	.name = "viocons",
539	.write = viocons_write,
540	.device = viocons_device,
541	.flags = CON_PRINTBUFFER,
542	.index = -1,
543};
544
545/*
546 * TTY Open method
547 */
548static int viotty_open(struct tty_struct *tty, struct file *filp)
549{
550	int port;
551	unsigned long flags;
552	struct port_info *pi;
553
554	port = tty->index;
555
556	if ((port < 0) || (port >= VTTY_PORTS))
557		return -ENODEV;
558
559	spin_lock_irqsave(&consolelock, flags);
560
561	pi = &port_info[port];
562	/* If some other TTY is already connected here, reject the open */
563	if ((pi->tty) && (pi->tty != tty)) {
564		spin_unlock_irqrestore(&consolelock, flags);
565		printk(VIOCONS_KERN_WARN
566		       "attempt to open device twice from different ttys\n");
567		return -EBUSY;
568	}
569	tty->driver_data = pi;
570	pi->tty = tty;
571	spin_unlock_irqrestore(&consolelock, flags);
572
573	return 0;
574}
575
576/*
577 * TTY Close method
578 */
579static void viotty_close(struct tty_struct *tty, struct file *filp)
580{
581	unsigned long flags;
582	struct port_info *pi;
583
584	spin_lock_irqsave(&consolelock, flags);
585	pi = (struct port_info *)tty->driver_data;
586
587	if (!pi || viotty_paranoia_check(pi, tty->name, "viotty_close")) {
588		spin_unlock_irqrestore(&consolelock, flags);
589		return;
590	}
591	if (tty->count == 1)
592		pi->tty = NULL;
593	spin_unlock_irqrestore(&consolelock, flags);
594}
595
596/*
597 * TTY Write method
598 */
599static int viotty_write(struct tty_struct *tty, const unsigned char *buf,
600		int count)
601{
602	struct port_info *pi;
603
604	pi = get_port_data(tty);
605	if (pi == NULL) {
606		hvlog("\n\rviotty_write: no port data.");
607		return -ENODEV;
608	}
609
610	if (viochar_is_console(pi))
611		hvlogOutput(buf, count);
612
613	/*
614	 * If the path to this LP is closed, don't bother doing anything more.
615	 * just dump the data on the floor and return count.  For some reason
616	 * some user level programs will attempt to probe available tty's and
617	 * they'll attempt a viotty_write on an invalid port which maps to an
618	 * invalid target lp.  If this is the case then ignore the
619	 * viotty_write call and, since the viopath isn't active to this
620	 * partition, return count.
621	 */
622	if (!viopath_isactive(pi->lp))
623		return count;
624
625	return internal_write(pi, buf, count);
626}
627
628/*
629 * TTY put_char method
630 */
631static void viotty_put_char(struct tty_struct *tty, unsigned char ch)
632{
633	struct port_info *pi;
634
635	pi = get_port_data(tty);
636	if (pi == NULL)
637		return;
638
639	/* This will append '\r' as well if the char is '\n' */
640	if (viochar_is_console(pi))
641		hvlogOutput(&ch, 1);
642
643	if (viopath_isactive(pi->lp))
644		internal_write(pi, &ch, 1);
645}
646
647/*
648 * TTY write_room method
649 */
650static int viotty_write_room(struct tty_struct *tty)
651{
652	int i;
653	int room = 0;
654	struct port_info *pi;
655	unsigned long flags;
656
657	spin_lock_irqsave(&consolelock, flags);
658	pi = (struct port_info *)tty->driver_data;
659	if (!pi || viotty_paranoia_check(pi, tty->name, "viotty_write_room")) {
660		spin_unlock_irqrestore(&consolelock, flags);
661		return 0;
662	}
663
664	/* If no buffers are used, return the max size. */
665	if (pi->used == 0) {
666		spin_unlock_irqrestore(&consolelock, flags);
667		return VIOCHAR_MAX_DATA * VIOCHAR_NUM_BUF;
668	}
669
670	/*
671	 * We retain the spinlock because we want to get an accurate
672	 * count and it can change on us between each operation if we
673	 * don't hold the spinlock.
674	 */
675	for (i = 0; ((i < VIOCHAR_NUM_BUF) && (room < VIOCHAR_MAX_DATA)); i++)
676		room += (VIOCHAR_MAX_DATA - pi->bufferBytes[i]);
677	spin_unlock_irqrestore(&consolelock, flags);
678
679	if (room > VIOCHAR_MAX_DATA)
680		room = VIOCHAR_MAX_DATA;
681	return room;
682}
683
684/*
685 * TTY chars_in_buffer method
686 */
687static int viotty_chars_in_buffer(struct tty_struct *tty)
688{
689	return 0;
690}
691
692static int viotty_ioctl(struct tty_struct *tty, struct file *file,
693			unsigned int cmd, unsigned long arg)
694{
695	switch (cmd) {
696	/*
697	 * the ioctls below read/set the flags usually shown in the leds
698	 * don't use them - they will go away without warning
699	 */
700	case KDGETLED:
701	case KDGKBLED:
702		return put_user(0, (char *)arg);
703
704	case KDSKBLED:
705		return 0;
706	}
707
708	return n_tty_ioctl(tty, file, cmd, arg);
709}
710
711/*
712 * Handle an open charLpEvent.  Could be either interrupt or ack
713 */
714static void vioHandleOpenEvent(struct HvLpEvent *event)
715{
716	unsigned long flags;
717	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
718	u8 port = cevent->virtual_device;
719	struct port_info *pi;
720	int reject = 0;
721
722	if (hvlpevent_is_ack(event)) {
723		if (port >= VTTY_PORTS)
724			return;
725
726		spin_lock_irqsave(&consolelock, flags);
727		/* Got the lock, don't cause console output */
728
729		pi = &port_info[port];
730		if (event->xRc == HvLpEvent_Rc_Good) {
731			pi->seq = pi->ack = 0;
732			/*
733			 * This line allows connections from the primary
734			 * partition but once one is connected from the
735			 * primary partition nothing short of a reboot
736			 * of linux will allow access from the hosting
737			 * partition again without a required iSeries fix.
738			 */
739			pi->lp = event->xTargetLp;
740		}
741
742		spin_unlock_irqrestore(&consolelock, flags);
743		if (event->xRc != HvLpEvent_Rc_Good)
744			printk(VIOCONS_KERN_WARN
745			       "handle_open_event: event->xRc == (%d).\n",
746			       event->xRc);
747
748		if (event->xCorrelationToken != 0) {
749			atomic_t *aptr= (atomic_t *)event->xCorrelationToken;
750			atomic_set(aptr, 1);
751		} else
752			printk(VIOCONS_KERN_WARN
753			       "weird...got open ack without atomic\n");
754		return;
755	}
756
757	/* This had better require an ack, otherwise complain */
758	if (!hvlpevent_need_ack(event)) {
759		printk(VIOCONS_KERN_WARN "viocharopen without ack bit!\n");
760		return;
761	}
762
763	spin_lock_irqsave(&consolelock, flags);
764	/* Got the lock, don't cause console output */
765
766	/* Make sure this is a good virtual tty */
767	if (port >= VTTY_PORTS) {
768		event->xRc = HvLpEvent_Rc_SubtypeError;
769		cevent->subtype_result_code = viorc_openRejected;
770		/*
771		 * Flag state here since we can't printk while holding
772		 * a spinlock.
773		 */
774		reject = 1;
775	} else {
776		pi = &port_info[port];
777		if ((pi->lp != HvLpIndexInvalid) &&
778				(pi->lp != event->xSourceLp)) {
779			/*
780			 * If this is tty is already connected to a different
781			 * partition, fail.
782			 */
783			event->xRc = HvLpEvent_Rc_SubtypeError;
784			cevent->subtype_result_code = viorc_openRejected;
785			reject = 2;
786		} else {
787			pi->lp = event->xSourceLp;
788			event->xRc = HvLpEvent_Rc_Good;
789			cevent->subtype_result_code = viorc_good;
790			pi->seq = pi->ack = 0;
791			reject = 0;
792		}
793	}
794
795	spin_unlock_irqrestore(&consolelock, flags);
796
797	if (reject == 1)
798		printk(VIOCONS_KERN_WARN "open rejected: bad virtual tty.\n");
799	else if (reject == 2)
800		printk(VIOCONS_KERN_WARN
801			"open rejected: console in exclusive use by another partition.\n");
802
803	/* Return the acknowledgement */
804	HvCallEvent_ackLpEvent(event);
805}
806
807/*
808 * Handle a close charLpEvent.  This should ONLY be an Interrupt because the
809 * virtual console should never actually issue a close event to the hypervisor
810 * because the virtual console never goes away.  A close event coming from the
811 * hypervisor simply means that there are no client consoles connected to the
812 * virtual console.
813 *
814 * Regardless of the number of connections masqueraded on the other side of
815 * the hypervisor ONLY ONE close event should be called to accompany the ONE
816 * open event that is called.  The close event should ONLY be called when NO
817 * MORE connections (masqueraded or not) exist on the other side of the
818 * hypervisor.
819 */
820static void vioHandleCloseEvent(struct HvLpEvent *event)
821{
822	unsigned long flags;
823	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
824	u8 port = cevent->virtual_device;
825
826	if (hvlpevent_is_int(event)) {
827		if (port >= VTTY_PORTS) {
828			printk(VIOCONS_KERN_WARN
829					"close message from invalid virtual device.\n");
830			return;
831		}
832
833		/* For closes, just mark the console partition invalid */
834		spin_lock_irqsave(&consolelock, flags);
835		/* Got the lock, don't cause console output */
836
837		if (port_info[port].lp == event->xSourceLp)
838			port_info[port].lp = HvLpIndexInvalid;
839
840		spin_unlock_irqrestore(&consolelock, flags);
841		printk(VIOCONS_KERN_INFO "close from %d\n", event->xSourceLp);
842	} else
843		printk(VIOCONS_KERN_WARN
844				"got unexpected close acknowlegement\n");
845}
846
847/*
848 * Handle a config charLpEvent.  Could be either interrupt or ack
849 */
850static void vioHandleConfig(struct HvLpEvent *event)
851{
852	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
853
854	HvCall_writeLogBuffer(cevent->data, cevent->len);
855
856	if (cevent->data[0] == 0x01)
857		printk(VIOCONS_KERN_INFO "window resized to %d: %d: %d: %d\n",
858		       cevent->data[1], cevent->data[2],
859		       cevent->data[3], cevent->data[4]);
860	else
861		printk(VIOCONS_KERN_WARN "unknown config event\n");
862}
863
864/*
865 * Handle a data charLpEvent.
866 */
867static void vioHandleData(struct HvLpEvent *event)
868{
869	struct tty_struct *tty;
870	unsigned long flags;
871	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
872	struct port_info *pi;
873	int index;
874	int num_pushed;
875	u8 port = cevent->virtual_device;
876
877	if (port >= VTTY_PORTS) {
878		printk(VIOCONS_KERN_WARN "data on invalid virtual device %d\n",
879				port);
880		return;
881	}
882
883	/*
884	 * Hold the spinlock so that we don't take an interrupt that
885	 * changes tty between the time we fetch the port_info
886	 * pointer and the time we paranoia check.
887	 */
888	spin_lock_irqsave(&consolelock, flags);
889	pi = &port_info[port];
890
891	/*
892	 * Change 05/01/2003 - Ryan Arnold: If a partition other than
893	 * the current exclusive partition tries to send us data
894	 * events then just drop them on the floor because we don't
895	 * want his stinking data.  He isn't authorized to receive
896	 * data because he wasn't the first one to get the console,
897	 * therefore he shouldn't be allowed to send data either.
898	 * This will work without an iSeries fix.
899	 */
900	if (pi->lp != event->xSourceLp) {
901		spin_unlock_irqrestore(&consolelock, flags);
902		return;
903	}
904
905	tty = pi->tty;
906	if (tty == NULL) {
907		spin_unlock_irqrestore(&consolelock, flags);
908		printk(VIOCONS_KERN_WARN "no tty for virtual device %d\n",
909				port);
910		return;
911	}
912
913	if (tty->magic != TTY_MAGIC) {
914		spin_unlock_irqrestore(&consolelock, flags);
915		printk(VIOCONS_KERN_WARN "tty bad magic\n");
916		return;
917	}
918
919	/*
920	 * Just to be paranoid, make sure the tty points back to this port
921	 */
922	pi = (struct port_info *)tty->driver_data;
923	if (!pi || viotty_paranoia_check(pi, tty->name, "vioHandleData")) {
924		spin_unlock_irqrestore(&consolelock, flags);
925		return;
926	}
927	spin_unlock_irqrestore(&consolelock, flags);
928
929	/*
930	 * Change 07/21/2003 - Ryan Arnold: functionality added to
931	 * support sysrq utilizing ^O as the sysrq key.  The sysrq
932	 * functionality will only work if built into the kernel and
933	 * then only if sysrq is enabled through the proc filesystem.
934	 */
935	num_pushed = 0;
936	for (index = 0; index < cevent->len; index++) {
937		/*
938		 * Will be optimized away if !CONFIG_MAGIC_SYSRQ:
939		 */
940		if (sysrq_on()) {
941			/* 0x0f is the ascii character for ^O */
942			if (cevent->data[index] == '\x0f') {
943				vio_sysrq_pressed = 1;
944				/*
945				 * continue because we don't want to add
946				 * the sysrq key into the data string.
947				 */
948				continue;
949			} else if (vio_sysrq_pressed) {
950				handle_sysrq(cevent->data[index], tty);
951				vio_sysrq_pressed = 0;
952				/*
953				 * continue because we don't want to add
954				 * the sysrq sequence into the data string.
955				 */
956				continue;
957			}
958		}
959		/*
960		 * The sysrq sequence isn't included in this check if
961		 * sysrq is enabled and compiled into the kernel because
962		 * the sequence will never get inserted into the buffer.
963		 * Don't attempt to copy more data into the buffer than we
964		 * have room for because it would fail without indication.
965		 */
966		if(tty_insert_flip_char(tty, cevent->data[index], TTY_NORMAL) == 0) {
967			printk(VIOCONS_KERN_WARN "input buffer overflow!\n");
968			break;
969		}
970		num_pushed++;
971	}
972
973	if (num_pushed)
974		tty_flip_buffer_push(tty);
975}
976
977/*
978 * Handle an ack charLpEvent.
979 */
980static void vioHandleAck(struct HvLpEvent *event)
981{
982	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
983	unsigned long flags;
984	u8 port = cevent->virtual_device;
985
986	if (port >= VTTY_PORTS) {
987		printk(VIOCONS_KERN_WARN "data on invalid virtual device\n");
988		return;
989	}
990
991	spin_lock_irqsave(&consolelock, flags);
992	port_info[port].ack = event->xCorrelationToken;
993	spin_unlock_irqrestore(&consolelock, flags);
994
995	if (port_info[port].used)
996		send_buffers(&port_info[port]);
997}
998
999/*
1000 * Handle charLpEvents and route to the appropriate routine
1001 */
1002static void vioHandleCharEvent(struct HvLpEvent *event)
1003{
1004	int charminor;
1005
1006	if (event == NULL)
1007		return;
1008
1009	charminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
1010	switch (charminor) {
1011	case viocharopen:
1012		vioHandleOpenEvent(event);
1013		break;
1014	case viocharclose:
1015		vioHandleCloseEvent(event);
1016		break;
1017	case viochardata:
1018		vioHandleData(event);
1019		break;
1020	case viocharack:
1021		vioHandleAck(event);
1022		break;
1023	case viocharconfig:
1024		vioHandleConfig(event);
1025		break;
1026	default:
1027		if (hvlpevent_is_int(event) && hvlpevent_need_ack(event)) {
1028			event->xRc = HvLpEvent_Rc_InvalidSubtype;
1029			HvCallEvent_ackLpEvent(event);
1030		}
1031	}
1032}
1033
1034/*
1035 * Send an open event
1036 */
1037static int send_open(HvLpIndex remoteLp, void *sem)
1038{
1039	return HvCallEvent_signalLpEventFast(remoteLp,
1040			HvLpEvent_Type_VirtualIo,
1041			viomajorsubtype_chario | viocharopen,
1042			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
1043			viopath_sourceinst(remoteLp),
1044			viopath_targetinst(remoteLp),
1045			(u64)(unsigned long)sem, VIOVERSION << 16,
1046			0, 0, 0, 0);
1047}
1048
1049static const struct tty_operations serial_ops = {
1050	.open = viotty_open,
1051	.close = viotty_close,
1052	.write = viotty_write,
1053	.put_char = viotty_put_char,
1054	.write_room = viotty_write_room,
1055	.chars_in_buffer = viotty_chars_in_buffer,
1056	.ioctl = viotty_ioctl,
1057};
1058
1059static int __init viocons_init2(void)
1060{
1061	atomic_t wait_flag;
1062	int rc;
1063
1064	if (!firmware_has_feature(FW_FEATURE_ISERIES))
1065		return -ENODEV;
1066
1067	/* +2 for fudge */
1068	rc = viopath_open(HvLpConfig_getPrimaryLpIndex(),
1069			viomajorsubtype_chario, VIOCHAR_WINDOW + 2);
1070	if (rc)
1071		printk(VIOCONS_KERN_WARN "error opening to primary %d\n", rc);
1072
1073	if (viopath_hostLp == HvLpIndexInvalid)
1074		vio_set_hostlp();
1075
1076	/*
1077	 * And if the primary is not the same as the hosting LP, open to the
1078	 * hosting lp
1079	 */
1080	if ((viopath_hostLp != HvLpIndexInvalid) &&
1081	    (viopath_hostLp != HvLpConfig_getPrimaryLpIndex())) {
1082		printk(VIOCONS_KERN_INFO "open path to hosting (%d)\n",
1083				viopath_hostLp);
1084		rc = viopath_open(viopath_hostLp, viomajorsubtype_chario,
1085				VIOCHAR_WINDOW + 2);	/* +2 for fudge */
1086		if (rc)
1087			printk(VIOCONS_KERN_WARN
1088				"error opening to partition %d: %d\n",
1089				viopath_hostLp, rc);
1090	}
1091
1092	if (vio_setHandler(viomajorsubtype_chario, vioHandleCharEvent) < 0)
1093		printk(VIOCONS_KERN_WARN
1094				"error seting handler for console events!\n");
1095
1096	/*
1097	 * First, try to open the console to the hosting lp.
1098	 * Wait on a semaphore for the response.
1099	 */
1100	atomic_set(&wait_flag, 0);
1101	if ((viopath_isactive(viopath_hostLp)) &&
1102	    (send_open(viopath_hostLp, (void *)&wait_flag) == 0)) {
1103		printk(VIOCONS_KERN_INFO "hosting partition %d\n",
1104			viopath_hostLp);
1105		while (atomic_read(&wait_flag) == 0)
1106			mb();
1107		atomic_set(&wait_flag, 0);
1108	}
1109
1110	/*
1111	 * If we don't have an active console, try the primary
1112	 */
1113	if ((!viopath_isactive(port_info[0].lp)) &&
1114	    (viopath_isactive(HvLpConfig_getPrimaryLpIndex())) &&
1115	    (send_open(HvLpConfig_getPrimaryLpIndex(), (void *)&wait_flag)
1116	     == 0)) {
1117		printk(VIOCONS_KERN_INFO "opening console to primary partition\n");
1118		while (atomic_read(&wait_flag) == 0)
1119			mb();
1120	}
1121
1122	/* Initialize the tty_driver structure */
1123	viotty_driver = alloc_tty_driver(VTTY_PORTS);
1124	viotty_driver->owner = THIS_MODULE;
1125	viotty_driver->driver_name = "vioconsole";
1126	viotty_driver->name = "tty";
1127	viotty_driver->name_base = 1;
1128	viotty_driver->major = TTY_MAJOR;
1129	viotty_driver->minor_start = 1;
1130	viotty_driver->type = TTY_DRIVER_TYPE_CONSOLE;
1131	viotty_driver->subtype = 1;
1132	viotty_driver->init_termios = tty_std_termios;
1133	viotty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
1134	tty_set_operations(viotty_driver, &serial_ops);
1135
1136	if (tty_register_driver(viotty_driver)) {
1137		printk(VIOCONS_KERN_WARN "couldn't register console driver\n");
1138		put_tty_driver(viotty_driver);
1139		viotty_driver = NULL;
1140	}
1141
1142	unregister_console(&viocons_early);
1143	register_console(&viocons);
1144
1145	return 0;
1146}
1147
1148static int __init viocons_init(void)
1149{
1150	int i;
1151
1152	if (!firmware_has_feature(FW_FEATURE_ISERIES))
1153		return -ENODEV;
1154
1155	printk(VIOCONS_KERN_INFO "registering console\n");
1156	for (i = 0; i < VTTY_PORTS; i++) {
1157		port_info[i].lp = HvLpIndexInvalid;
1158		port_info[i].magic = VIOTTY_MAGIC;
1159	}
1160	HvCall_setLogBufferFormatAndCodepage(HvCall_LogBuffer_ASCII, 437);
1161	add_preferred_console("viocons", 0, NULL);
1162	register_console(&viocons_early);
1163	return 0;
1164}
1165
1166console_initcall(viocons_init);
1167module_init(viocons_init2);
1168