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