f144a947bd17aaa8549230e307c13def30296822
[sfrench/cifs-2.6.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 struct hv_ops hvc_get_put_ops = {
201         .get_chars = get_chars,
202         .put_chars = put_chars,
203 };
204
205 static 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
230 static 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
238 static 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
248 static 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  */
345 static 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
372 static 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
415 static 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
431 static 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
443 static 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
475 static 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
487 static 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 }
553 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
554
555 static void hvc_vio_exit(void)
556 {
557         vio_unregister_driver(&hvc_vio_driver);
558 }
559 module_exit(hvc_vio_exit);
560
561 /* the device tree order defines our numbering */
562 static 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 = get_property(vty, "reg", NULL);
579                 if (!vtermno)
580                         continue;
581
582                 if (!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 }
593 console_initcall(hvc_find_vtys);