Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-3.10.git] / drivers / char / hvc_iseries.c
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
42 static DEFINE_SPINLOCK(consolelock);
43 static DEFINE_SPINLOCK(consoleloglock);
44
45 static const char hvc_driver_name[] = "hvc_console";
46
47 #define IN_BUF_SIZE     200
48
49 /*
50  * Our port information.
51  */
52 static 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
68 static struct vio_device_id hvc_driver_table[] __devinitdata = {
69         {"serial", "IBM,iSeries-vty"},
70         { "", "" }
71 };
72 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
73
74 static 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  */
93 static 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
110 static 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         }
136 done:
137         spin_unlock_irqrestore(&consolelock, flags);
138         return n;
139 }
140
141 static 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);
195 done:
196         spin_unlock_irqrestore(&consolelock, flags);
197         return sent;
198 }
199
200 static const struct hv_ops hvc_get_put_ops = {
201         .get_chars = get_chars,
202         .put_chars = put_chars,
203         .notifier_add = notifier_add_irq,
204         .notifier_del = notifier_del_irq,
205         .notifier_hangup = notifier_hangup_irq,
206 };
207
208 static int __devinit hvc_vio_probe(struct vio_dev *vdev,
209                         const struct vio_device_id *id)
210 {
211         struct hvc_struct *hp;
212         struct port_info *pi;
213
214         /* probed with invalid parameters. */
215         if (!vdev || !id)
216                 return -EPERM;
217
218         if (vdev->unit_address >= VTTY_PORTS)
219                 return -ENODEV;
220
221         pi = &port_info[vdev->unit_address];
222
223         hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
224                         VIOCHAR_MAX_DATA);
225         if (IS_ERR(hp))
226                 return PTR_ERR(hp);
227         pi->hp = hp;
228         dev_set_drvdata(&vdev->dev, pi);
229
230         return 0;
231 }
232
233 static int __devexit hvc_vio_remove(struct vio_dev *vdev)
234 {
235         struct port_info *pi = dev_get_drvdata(&vdev->dev);
236         struct hvc_struct *hp = pi->hp;
237
238         return hvc_remove(hp);
239 }
240
241 static struct vio_driver hvc_vio_driver = {
242         .id_table       = hvc_driver_table,
243         .probe          = hvc_vio_probe,
244         .remove         = __devexit_p(hvc_vio_remove),
245         .driver         = {
246                 .name   = hvc_driver_name,
247                 .owner  = THIS_MODULE,
248         }
249 };
250
251 static void hvc_open_event(struct HvLpEvent *event)
252 {
253         unsigned long flags;
254         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
255         u8 port = cevent->virtual_device;
256         struct port_info *pi;
257         int reject = 0;
258
259         if (hvlpevent_is_ack(event)) {
260                 if (port >= VTTY_PORTS)
261                         return;
262
263                 spin_lock_irqsave(&consolelock, flags);
264
265                 pi = &port_info[port];
266                 if (event->xRc == HvLpEvent_Rc_Good) {
267                         pi->seq = pi->ack = 0;
268                         /*
269                          * This line allows connections from the primary
270                          * partition but once one is connected from the
271                          * primary partition nothing short of a reboot
272                          * of linux will allow access from the hosting
273                          * partition again without a required iSeries fix.
274                          */
275                         pi->lp = event->xTargetLp;
276                 }
277
278                 spin_unlock_irqrestore(&consolelock, flags);
279                 if (event->xRc != HvLpEvent_Rc_Good)
280                         printk(KERN_WARNING
281                                "hvc: handle_open_event: event->xRc == (%d).\n",
282                                event->xRc);
283
284                 if (event->xCorrelationToken != 0) {
285                         atomic_t *aptr= (atomic_t *)event->xCorrelationToken;
286                         atomic_set(aptr, 1);
287                 } else
288                         printk(KERN_WARNING
289                                "hvc: weird...got open ack without atomic\n");
290                 return;
291         }
292
293         /* This had better require an ack, otherwise complain */
294         if (!hvlpevent_need_ack(event)) {
295                 printk(KERN_WARNING "hvc: viocharopen without ack bit!\n");
296                 return;
297         }
298
299         spin_lock_irqsave(&consolelock, flags);
300
301         /* Make sure this is a good virtual tty */
302         if (port >= VTTY_PORTS) {
303                 event->xRc = HvLpEvent_Rc_SubtypeError;
304                 cevent->subtype_result_code = viorc_openRejected;
305                 /*
306                  * Flag state here since we can't printk while holding
307                  * the consolelock spinlock.
308                  */
309                 reject = 1;
310         } else {
311                 pi = &port_info[port];
312                 if ((pi->lp != HvLpIndexInvalid) &&
313                                 (pi->lp != event->xSourceLp)) {
314                         /*
315                          * If this is tty is already connected to a different
316                          * partition, fail.
317                          */
318                         event->xRc = HvLpEvent_Rc_SubtypeError;
319                         cevent->subtype_result_code = viorc_openRejected;
320                         reject = 2;
321                 } else {
322                         pi->lp = event->xSourceLp;
323                         event->xRc = HvLpEvent_Rc_Good;
324                         cevent->subtype_result_code = viorc_good;
325                         pi->seq = pi->ack = 0;
326                 }
327         }
328
329         spin_unlock_irqrestore(&consolelock, flags);
330
331         if (reject == 1)
332                 printk(KERN_WARNING "hvc: open rejected: bad virtual tty.\n");
333         else if (reject == 2)
334                 printk(KERN_WARNING "hvc: open rejected: console in exclusive "
335                                 "use by another partition.\n");
336
337         /* Return the acknowledgement */
338         HvCallEvent_ackLpEvent(event);
339 }
340
341 /*
342  * Handle a close charLpEvent.  This should ONLY be an Interrupt because the
343  * virtual console should never actually issue a close event to the hypervisor
344  * because the virtual console never goes away.  A close event coming from the
345  * hypervisor simply means that there are no client consoles connected to the
346  * virtual console.
347  */
348 static void hvc_close_event(struct HvLpEvent *event)
349 {
350         unsigned long flags;
351         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
352         u8 port = cevent->virtual_device;
353
354         if (!hvlpevent_is_int(event)) {
355                 printk(KERN_WARNING
356                         "hvc: got unexpected close acknowledgement\n");
357                 return;
358         }
359
360         if (port >= VTTY_PORTS) {
361                 printk(KERN_WARNING
362                         "hvc: close message from invalid virtual device.\n");
363                 return;
364         }
365
366         /* For closes, just mark the console partition invalid */
367         spin_lock_irqsave(&consolelock, flags);
368
369         if (port_info[port].lp == event->xSourceLp)
370                 port_info[port].lp = HvLpIndexInvalid;
371
372         spin_unlock_irqrestore(&consolelock, flags);
373 }
374
375 static void hvc_data_event(struct HvLpEvent *event)
376 {
377         unsigned long flags;
378         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
379         struct port_info *pi;
380         int n;
381         u8 port = cevent->virtual_device;
382
383         if (port >= VTTY_PORTS) {
384                 printk(KERN_WARNING "hvc: data on invalid virtual device %d\n",
385                                 port);
386                 return;
387         }
388         if (cevent->len == 0)
389                 return;
390
391         /*
392          * Change 05/01/2003 - Ryan Arnold: If a partition other than
393          * the current exclusive partition tries to send us data
394          * events then just drop them on the floor because we don't
395          * want his stinking data.  He isn't authorized to receive
396          * data because he wasn't the first one to get the console,
397          * therefore he shouldn't be allowed to send data either.
398          * This will work without an iSeries fix.
399          */
400         pi = &port_info[port];
401         if (pi->lp != event->xSourceLp)
402                 return;
403
404         spin_lock_irqsave(&consolelock, flags);
405
406         n = IN_BUF_SIZE - pi->in_end;
407         if (n > cevent->len)
408                 n = cevent->len;
409         if (n > 0) {
410                 memcpy(&pi->in_buf[pi->in_end], cevent->data, n);
411                 pi->in_end += n;
412         }
413         spin_unlock_irqrestore(&consolelock, flags);
414         if (n == 0)
415                 printk(KERN_WARNING "hvc: input buffer overflow\n");
416 }
417
418 static void hvc_ack_event(struct HvLpEvent *event)
419 {
420         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
421         unsigned long flags;
422         u8 port = cevent->virtual_device;
423
424         if (port >= VTTY_PORTS) {
425                 printk(KERN_WARNING "hvc: data on invalid virtual device\n");
426                 return;
427         }
428
429         spin_lock_irqsave(&consolelock, flags);
430         port_info[port].ack = event->xCorrelationToken;
431         spin_unlock_irqrestore(&consolelock, flags);
432 }
433
434 static void hvc_config_event(struct HvLpEvent *event)
435 {
436         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
437
438         if (cevent->data[0] == 0x01)
439                 printk(KERN_INFO "hvc: window resized to %d: %d: %d: %d\n",
440                        cevent->data[1], cevent->data[2],
441                        cevent->data[3], cevent->data[4]);
442         else
443                 printk(KERN_WARNING "hvc: unknown config event\n");
444 }
445
446 static void hvc_handle_event(struct HvLpEvent *event)
447 {
448         int charminor;
449
450         if (event == NULL)
451                 return;
452
453         charminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
454         switch (charminor) {
455         case viocharopen:
456                 hvc_open_event(event);
457                 break;
458         case viocharclose:
459                 hvc_close_event(event);
460                 break;
461         case viochardata:
462                 hvc_data_event(event);
463                 break;
464         case viocharack:
465                 hvc_ack_event(event);
466                 break;
467         case viocharconfig:
468                 hvc_config_event(event);
469                 break;
470         default:
471                 if (hvlpevent_is_int(event) && hvlpevent_need_ack(event)) {
472                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
473                         HvCallEvent_ackLpEvent(event);
474                 }
475         }
476 }
477
478 static int __init send_open(HvLpIndex remoteLp, void *sem)
479 {
480         return HvCallEvent_signalLpEventFast(remoteLp,
481                         HvLpEvent_Type_VirtualIo,
482                         viomajorsubtype_chario | viocharopen,
483                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
484                         viopath_sourceinst(remoteLp),
485                         viopath_targetinst(remoteLp),
486                         (u64)(unsigned long)sem, VIOVERSION << 16,
487                         0, 0, 0, 0);
488 }
489
490 static int __init hvc_vio_init(void)
491 {
492         atomic_t wait_flag;
493         int rc;
494
495         if (!firmware_has_feature(FW_FEATURE_ISERIES))
496                 return -EIO;
497
498         /* +2 for fudge */
499         rc = viopath_open(HvLpConfig_getPrimaryLpIndex(),
500                         viomajorsubtype_chario, VIOCHAR_WINDOW + 2);
501         if (rc)
502                 printk(KERN_WARNING "hvc: error opening to primary %d\n", rc);
503
504         if (viopath_hostLp == HvLpIndexInvalid)
505                 vio_set_hostlp();
506
507         /*
508          * And if the primary is not the same as the hosting LP, open to the
509          * hosting lp
510          */
511         if ((viopath_hostLp != HvLpIndexInvalid) &&
512             (viopath_hostLp != HvLpConfig_getPrimaryLpIndex())) {
513                 printk(KERN_INFO "hvc: open path to hosting (%d)\n",
514                                 viopath_hostLp);
515                 rc = viopath_open(viopath_hostLp, viomajorsubtype_chario,
516                                 VIOCHAR_WINDOW + 2);    /* +2 for fudge */
517                 if (rc)
518                         printk(KERN_WARNING
519                                 "error opening to partition %d: %d\n",
520                                 viopath_hostLp, rc);
521         }
522
523         if (vio_setHandler(viomajorsubtype_chario, hvc_handle_event) < 0)
524                 printk(KERN_WARNING
525                         "hvc: error seting handler for console events!\n");
526
527         /*
528          * First, try to open the console to the hosting lp.
529          * Wait on a semaphore for the response.
530          */
531         atomic_set(&wait_flag, 0);
532         if ((viopath_isactive(viopath_hostLp)) &&
533             (send_open(viopath_hostLp, &wait_flag) == 0)) {
534                 printk(KERN_INFO "hvc: hosting partition %d\n", viopath_hostLp);
535                 while (atomic_read(&wait_flag) == 0)
536                         mb();
537                 atomic_set(&wait_flag, 0);
538         }
539
540         /*
541          * If we don't have an active console, try the primary
542          */
543         if ((!viopath_isactive(port_info[0].lp)) &&
544             (viopath_isactive(HvLpConfig_getPrimaryLpIndex())) &&
545             (send_open(HvLpConfig_getPrimaryLpIndex(), &wait_flag) == 0)) {
546                 printk(KERN_INFO "hvc: opening console to primary partition\n");
547                 while (atomic_read(&wait_flag) == 0)
548                         mb();
549         }
550
551         /* Register as a vio device to receive callbacks */
552         rc = vio_register_driver(&hvc_vio_driver);
553
554         return rc;
555 }
556 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
557
558 static void __exit hvc_vio_exit(void)
559 {
560         vio_unregister_driver(&hvc_vio_driver);
561 }
562 module_exit(hvc_vio_exit);
563
564 /* the device tree order defines our numbering */
565 static int __init hvc_find_vtys(void)
566 {
567         struct device_node *vty;
568         int num_found = 0;
569
570         for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
571                         vty = of_find_node_by_name(vty, "vty")) {
572                 const uint32_t *vtermno;
573
574                 /* We have statically defined space for only a certain number
575                  * of console adapters.
576                  */
577                 if ((num_found >= MAX_NR_HVC_CONSOLES) ||
578                                 (num_found >= VTTY_PORTS)) {
579                         of_node_put(vty);
580                         break;
581                 }
582
583                 vtermno = of_get_property(vty, "reg", NULL);
584                 if (!vtermno)
585                         continue;
586
587                 if (!of_device_is_compatible(vty, "IBM,iSeries-vty"))
588                         continue;
589
590                 if (num_found == 0)
591                         add_preferred_console("hvc", 0, NULL);
592                 hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
593                 ++num_found;
594         }
595
596         return num_found;
597 }
598 console_initcall(hvc_find_vtys);