1/*
2 * iSeries vio driver interface to hvc_console.c
3 *
4 * This code is based heavily on hvc_vio.c and viocons.c
5 *
6 * Copyright (C) 2006 Stephen Rothwell, IBM Corporation
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
21 */
22#include <stdarg.h>
23#include <linux/types.h>
24#include <linux/init.h>
25#include <linux/kernel.h>
26#include <linux/spinlock.h>
27#include <linux/console.h>
28
29#include <asm/hvconsole.h>
30#include <asm/vio.h>
31#include <asm/prom.h>
32#include <asm/firmware.h>
33#include <asm/iseries/vio.h>
34#include <asm/iseries/hv_call.h>
35#include <asm/iseries/hv_lp_config.h>
36#include <asm/iseries/hv_lp_event.h>
37
38#include "hvc_console.h"
39
40#define VTTY_PORTS 10
41
42static DEFINE_SPINLOCK(consolelock);
43static DEFINE_SPINLOCK(consoleloglock);
44
45static const char hvc_driver_name[] = "hvc_console";
46
47#define IN_BUF_SIZE	200
48
49/*
50 * Our port information.
51 */
52static struct port_info {
53	HvLpIndex lp;
54	u64 seq;	/* sequence number of last HV send */
55	u64 ack;	/* last ack from HV */
56	struct hvc_struct *hp;
57	int in_start;
58	int in_end;
59	unsigned char in_buf[IN_BUF_SIZE];
60} port_info[VTTY_PORTS] = {
61	[ 0 ... VTTY_PORTS - 1 ] = {
62		.lp = HvLpIndexInvalid
63	}
64};
65
66#define viochar_is_console(pi)	((pi) == &port_info[0])
67
68static struct vio_device_id hvc_driver_table[] __devinitdata = {
69	{"serial", "IBM,iSeries-vty"},
70	{ "", "" }
71};
72MODULE_DEVICE_TABLE(vio, hvc_driver_table);
73
74static void hvlog(char *fmt, ...)
75{
76	int i;
77	unsigned long flags;
78	va_list args;
79	static char buf[256];
80
81	spin_lock_irqsave(&consoleloglock, flags);
82	va_start(args, fmt);
83	i = vscnprintf(buf, sizeof(buf) - 1, fmt, args);
84	va_end(args);
85	buf[i++] = '\r';
86	HvCall_writeLogBuffer(buf, i);
87	spin_unlock_irqrestore(&consoleloglock, flags);
88}
89
90/*
91 * Initialize the common fields in a charLpEvent
92 */
93static void init_data_event(struct viocharlpevent *viochar, HvLpIndex lp)
94{
95	struct HvLpEvent *hev = &viochar->event;
96
97	memset(viochar, 0, sizeof(struct viocharlpevent));
98
99	hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DEFERRED_ACK |
100		HV_LP_EVENT_INT;
101	hev->xType = HvLpEvent_Type_VirtualIo;
102	hev->xSubtype = viomajorsubtype_chario | viochardata;
103	hev->xSourceLp = HvLpConfig_getLpIndex();
104	hev->xTargetLp = lp;
105	hev->xSizeMinus1 = sizeof(struct viocharlpevent);
106	hev->xSourceInstanceId = viopath_sourceinst(lp);
107	hev->xTargetInstanceId = viopath_targetinst(lp);
108}
109
110static int get_chars(uint32_t vtermno, char *buf, int count)
111{
112	struct port_info *pi;
113	int n = 0;
114	unsigned long flags;
115
116	if (vtermno >= VTTY_PORTS)
117		return -EINVAL;
118	if (count == 0)
119		return 0;
120
121	pi = &port_info[vtermno];
122	spin_lock_irqsave(&consolelock, flags);
123
124	if (pi->in_end == 0)
125		goto done;
126
127	n = pi->in_end - pi->in_start;
128	if (n > count)
129		n = count;
130	memcpy(buf, &pi->in_buf[pi->in_start], n);
131	pi->in_start += n;
132	if (pi->in_start == pi->in_end) {
133		pi->in_start = 0;
134		pi->in_end = 0;
135	}
136done:
137	spin_unlock_irqrestore(&consolelock, flags);
138	return n;
139}
140
141static int put_chars(uint32_t vtermno, const char *buf, int count)
142{
143	struct viocharlpevent *viochar;
144	struct port_info *pi;
145	HvLpEvent_Rc hvrc;
146	unsigned long flags;
147	int sent = 0;
148
149	if (vtermno >= VTTY_PORTS)
150		return -EINVAL;
151
152	pi = &port_info[vtermno];
153
154	spin_lock_irqsave(&consolelock, flags);
155
156	if (viochar_is_console(pi) && !viopath_isactive(pi->lp)) {
157		HvCall_writeLogBuffer(buf, count);
158		sent = count;
159		goto done;
160	}
161
162	viochar = vio_get_event_buffer(viomajorsubtype_chario);
163	if (viochar == NULL) {
164		hvlog("\n\rviocons: Can't get viochar buffer.");
165		goto done;
166	}
167
168	while ((count > 0) && ((pi->seq - pi->ack) < VIOCHAR_WINDOW)) {
169		int len;
170
171		len = (count > VIOCHAR_MAX_DATA) ? VIOCHAR_MAX_DATA : count;
172
173		if (viochar_is_console(pi))
174			HvCall_writeLogBuffer(buf, len);
175
176		init_data_event(viochar, pi->lp);
177
178		viochar->len = len;
179		viochar->event.xCorrelationToken = pi->seq++;
180		viochar->event.xSizeMinus1 =
181			offsetof(struct viocharlpevent, data) + len;
182
183		memcpy(viochar->data, buf, len);
184
185		hvrc = HvCallEvent_signalLpEvent(&viochar->event);
186		if (hvrc)
187			hvlog("\n\rerror sending event! return code %d\n\r",
188				(int)hvrc);
189		sent += len;
190		count -= len;
191		buf += len;
192	}
193
194	vio_free_event_buffer(viomajorsubtype_chario, viochar);
195done:
196	spin_unlock_irqrestore(&consolelock, flags);
197	return sent;
198}
199
200static struct hv_ops hvc_get_put_ops = {
201	.get_chars = get_chars,
202	.put_chars = put_chars,
203};
204
205static int __devinit hvc_vio_probe(struct vio_dev *vdev,
206			const struct vio_device_id *id)
207{
208	struct hvc_struct *hp;
209	struct port_info *pi;
210
211	/* probed with invalid parameters. */
212	if (!vdev || !id)
213		return -EPERM;
214
215	if (vdev->unit_address >= VTTY_PORTS)
216		return -ENODEV;
217
218	pi = &port_info[vdev->unit_address];
219
220	hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
221			VIOCHAR_MAX_DATA);
222	if (IS_ERR(hp))
223		return PTR_ERR(hp);
224	pi->hp = hp;
225	dev_set_drvdata(&vdev->dev, pi);
226
227	return 0;
228}
229
230static int __devexit hvc_vio_remove(struct vio_dev *vdev)
231{
232	struct port_info *pi = dev_get_drvdata(&vdev->dev);
233	struct hvc_struct *hp = pi->hp;
234
235	return hvc_remove(hp);
236}
237
238static struct vio_driver hvc_vio_driver = {
239	.id_table	= hvc_driver_table,
240	.probe		= hvc_vio_probe,
241	.remove		= hvc_vio_remove,
242	.driver		= {
243		.name	= hvc_driver_name,
244		.owner	= THIS_MODULE,
245	}
246};
247
248static void hvc_open_event(struct HvLpEvent *event)
249{
250	unsigned long flags;
251	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
252	u8 port = cevent->virtual_device;
253	struct port_info *pi;
254	int reject = 0;
255
256	if (hvlpevent_is_ack(event)) {
257		if (port >= VTTY_PORTS)
258			return;
259
260		spin_lock_irqsave(&consolelock, flags);
261
262		pi = &port_info[port];
263		if (event->xRc == HvLpEvent_Rc_Good) {
264			pi->seq = pi->ack = 0;
265			/*
266			 * This line allows connections from the primary
267			 * partition but once one is connected from the
268			 * primary partition nothing short of a reboot
269			 * of linux will allow access from the hosting
270			 * partition again without a required iSeries fix.
271			 */
272			pi->lp = event->xTargetLp;
273		}
274
275		spin_unlock_irqrestore(&consolelock, flags);
276		if (event->xRc != HvLpEvent_Rc_Good)
277			printk(KERN_WARNING
278			       "hvc: handle_open_event: event->xRc == (%d).\n",
279			       event->xRc);
280
281		if (event->xCorrelationToken != 0) {
282			atomic_t *aptr= (atomic_t *)event->xCorrelationToken;
283			atomic_set(aptr, 1);
284		} else
285			printk(KERN_WARNING
286			       "hvc: weird...got open ack without atomic\n");
287		return;
288	}
289
290	/* This had better require an ack, otherwise complain */
291	if (!hvlpevent_need_ack(event)) {
292		printk(KERN_WARNING "hvc: viocharopen without ack bit!\n");
293		return;
294	}
295
296	spin_lock_irqsave(&consolelock, flags);
297
298	/* Make sure this is a good virtual tty */
299	if (port >= VTTY_PORTS) {
300		event->xRc = HvLpEvent_Rc_SubtypeError;
301		cevent->subtype_result_code = viorc_openRejected;
302		/*
303		 * Flag state here since we can't printk while holding
304		 * the consolelock spinlock.
305		 */
306		reject = 1;
307	} else {
308		pi = &port_info[port];
309		if ((pi->lp != HvLpIndexInvalid) &&
310				(pi->lp != event->xSourceLp)) {
311			/*
312			 * If this is tty is already connected to a different
313			 * partition, fail.
314			 */
315			event->xRc = HvLpEvent_Rc_SubtypeError;
316			cevent->subtype_result_code = viorc_openRejected;
317			reject = 2;
318		} else {
319			pi->lp = event->xSourceLp;
320			event->xRc = HvLpEvent_Rc_Good;
321			cevent->subtype_result_code = viorc_good;
322			pi->seq = pi->ack = 0;
323		}
324	}
325
326	spin_unlock_irqrestore(&consolelock, flags);
327
328	if (reject == 1)
329		printk(KERN_WARNING "hvc: open rejected: bad virtual tty.\n");
330	else if (reject == 2)
331		printk(KERN_WARNING "hvc: open rejected: console in exclusive "
332				"use by another partition.\n");
333
334	/* Return the acknowledgement */
335	HvCallEvent_ackLpEvent(event);
336}
337
338/*
339 * Handle a close charLpEvent.  This should ONLY be an Interrupt because the
340 * virtual console should never actually issue a close event to the hypervisor
341 * because the virtual console never goes away.  A close event coming from the
342 * hypervisor simply means that there are no client consoles connected to the
343 * virtual console.
344 */
345static void hvc_close_event(struct HvLpEvent *event)
346{
347	unsigned long flags;
348	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
349	u8 port = cevent->virtual_device;
350
351	if (!hvlpevent_is_int(event)) {
352		printk(KERN_WARNING
353			"hvc: got unexpected close acknowlegement\n");
354		return;
355	}
356
357	if (port >= VTTY_PORTS) {
358		printk(KERN_WARNING
359			"hvc: close message from invalid virtual device.\n");
360		return;
361	}
362
363	/* For closes, just mark the console partition invalid */
364	spin_lock_irqsave(&consolelock, flags);
365
366	if (port_info[port].lp == event->xSourceLp)
367		port_info[port].lp = HvLpIndexInvalid;
368
369	spin_unlock_irqrestore(&consolelock, flags);
370}
371
372static void hvc_data_event(struct HvLpEvent *event)
373{
374	unsigned long flags;
375	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
376	struct port_info *pi;
377	int n;
378	u8 port = cevent->virtual_device;
379
380	if (port >= VTTY_PORTS) {
381		printk(KERN_WARNING "hvc: data on invalid virtual device %d\n",
382				port);
383		return;
384	}
385	if (cevent->len == 0)
386		return;
387
388	/*
389	 * Change 05/01/2003 - Ryan Arnold: If a partition other than
390	 * the current exclusive partition tries to send us data
391	 * events then just drop them on the floor because we don't
392	 * want his stinking data.  He isn't authorized to receive
393	 * data because he wasn't the first one to get the console,
394	 * therefore he shouldn't be allowed to send data either.
395	 * This will work without an iSeries fix.
396	 */
397	pi = &port_info[port];
398	if (pi->lp != event->xSourceLp)
399		return;
400
401	spin_lock_irqsave(&consolelock, flags);
402
403	n = IN_BUF_SIZE - pi->in_end;
404	if (n > cevent->len)
405		n = cevent->len;
406	if (n > 0) {
407		memcpy(&pi->in_buf[pi->in_end], cevent->data, n);
408		pi->in_end += n;
409	}
410	spin_unlock_irqrestore(&consolelock, flags);
411	if (n == 0)
412		printk(KERN_WARNING "hvc: input buffer overflow\n");
413}
414
415static void hvc_ack_event(struct HvLpEvent *event)
416{
417	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
418	unsigned long flags;
419	u8 port = cevent->virtual_device;
420
421	if (port >= VTTY_PORTS) {
422		printk(KERN_WARNING "hvc: data on invalid virtual device\n");
423		return;
424	}
425
426	spin_lock_irqsave(&consolelock, flags);
427	port_info[port].ack = event->xCorrelationToken;
428	spin_unlock_irqrestore(&consolelock, flags);
429}
430
431static void hvc_config_event(struct HvLpEvent *event)
432{
433	struct viocharlpevent *cevent = (struct viocharlpevent *)event;
434
435	if (cevent->data[0] == 0x01)
436		printk(KERN_INFO "hvc: window resized to %d: %d: %d: %d\n",
437		       cevent->data[1], cevent->data[2],
438		       cevent->data[3], cevent->data[4]);
439	else
440		printk(KERN_WARNING "hvc: unknown config event\n");
441}
442
443static void hvc_handle_event(struct HvLpEvent *event)
444{
445	int charminor;
446
447	if (event == NULL)
448		return;
449
450	charminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
451	switch (charminor) {
452	case viocharopen:
453		hvc_open_event(event);
454		break;
455	case viocharclose:
456		hvc_close_event(event);
457		break;
458	case viochardata:
459		hvc_data_event(event);
460		break;
461	case viocharack:
462		hvc_ack_event(event);
463		break;
464	case viocharconfig:
465		hvc_config_event(event);
466		break;
467	default:
468		if (hvlpevent_is_int(event) && hvlpevent_need_ack(event)) {
469			event->xRc = HvLpEvent_Rc_InvalidSubtype;
470			HvCallEvent_ackLpEvent(event);
471		}
472	}
473}
474
475static int send_open(HvLpIndex remoteLp, void *sem)
476{
477	return HvCallEvent_signalLpEventFast(remoteLp,
478			HvLpEvent_Type_VirtualIo,
479			viomajorsubtype_chario | viocharopen,
480			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
481			viopath_sourceinst(remoteLp),
482			viopath_targetinst(remoteLp),
483			(u64)(unsigned long)sem, VIOVERSION << 16,
484			0, 0, 0, 0);
485}
486
487static int hvc_vio_init(void)
488{
489	atomic_t wait_flag;
490	int rc;
491
492	if (!firmware_has_feature(FW_FEATURE_ISERIES))
493		return -EIO;
494
495	/* +2 for fudge */
496	rc = viopath_open(HvLpConfig_getPrimaryLpIndex(),
497			viomajorsubtype_chario, VIOCHAR_WINDOW + 2);
498	if (rc)
499		printk(KERN_WARNING "hvc: error opening to primary %d\n", rc);
500
501	if (viopath_hostLp == HvLpIndexInvalid)
502		vio_set_hostlp();
503
504	/*
505	 * And if the primary is not the same as the hosting LP, open to the
506	 * hosting lp
507	 */
508	if ((viopath_hostLp != HvLpIndexInvalid) &&
509	    (viopath_hostLp != HvLpConfig_getPrimaryLpIndex())) {
510		printk(KERN_INFO "hvc: open path to hosting (%d)\n",
511				viopath_hostLp);
512		rc = viopath_open(viopath_hostLp, viomajorsubtype_chario,
513				VIOCHAR_WINDOW + 2);	/* +2 for fudge */
514		if (rc)
515			printk(KERN_WARNING
516				"error opening to partition %d: %d\n",
517				viopath_hostLp, rc);
518	}
519
520	if (vio_setHandler(viomajorsubtype_chario, hvc_handle_event) < 0)
521		printk(KERN_WARNING
522			"hvc: error seting handler for console events!\n");
523
524	/*
525	 * First, try to open the console to the hosting lp.
526	 * Wait on a semaphore for the response.
527	 */
528	atomic_set(&wait_flag, 0);
529	if ((viopath_isactive(viopath_hostLp)) &&
530	    (send_open(viopath_hostLp, &wait_flag) == 0)) {
531		printk(KERN_INFO "hvc: hosting partition %d\n", viopath_hostLp);
532		while (atomic_read(&wait_flag) == 0)
533			mb();
534		atomic_set(&wait_flag, 0);
535	}
536
537	/*
538	 * If we don't have an active console, try the primary
539	 */
540	if ((!viopath_isactive(port_info[0].lp)) &&
541	    (viopath_isactive(HvLpConfig_getPrimaryLpIndex())) &&
542	    (send_open(HvLpConfig_getPrimaryLpIndex(), &wait_flag) == 0)) {
543		printk(KERN_INFO "hvc: opening console to primary partition\n");
544		while (atomic_read(&wait_flag) == 0)
545			mb();
546	}
547
548	/* Register as a vio device to receive callbacks */
549	rc = vio_register_driver(&hvc_vio_driver);
550
551	return rc;
552}
553module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
554
555static void hvc_vio_exit(void)
556{
557	vio_unregister_driver(&hvc_vio_driver);
558}
559module_exit(hvc_vio_exit);
560
561/* the device tree order defines our numbering */
562static int hvc_find_vtys(void)
563{
564	struct device_node *vty;
565	int num_found = 0;
566
567	for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
568			vty = of_find_node_by_name(vty, "vty")) {
569		const uint32_t *vtermno;
570
571		/* We have statically defined space for only a certain number
572		 * of console adapters.
573		 */
574		if ((num_found >= MAX_NR_HVC_CONSOLES) ||
575				(num_found >= VTTY_PORTS))
576			break;
577
578		vtermno = of_get_property(vty, "reg", NULL);
579		if (!vtermno)
580			continue;
581
582		if (!of_device_is_compatible(vty, "IBM,iSeries-vty"))
583			continue;
584
585		if (num_found == 0)
586			add_preferred_console("hvc", 0, NULL);
587		hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
588		++num_found;
589	}
590
591	return num_found;
592}
593console_initcall(hvc_find_vtys);
594