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                 spin_lock_irqsave(&consoleloglock, flags);
 157                 HvCall_writeLogBuffer(buf, count);
 158                 spin_unlock_irqrestore(&consoleloglock, flags);
 159                 sent = count;
 160                 goto done;
 161         }
 162
 163         viochar = vio_get_event_buffer(viomajorsubtype_chario);
 164         if (viochar == NULL) {
 165                 hvlog("\n\rviocons: Can't get viochar buffer.");
 166                 goto done;
 167         }
 168
 169         while ((count > 0) && ((pi->seq - pi->ack) < VIOCHAR_WINDOW)) {
 170                 int len;
 171
 172                 len = (count > VIOCHAR_MAX_DATA) ? VIOCHAR_MAX_DATA : count;
 173
 174                 if (viochar_is_console(pi)) {
 175                         spin_lock_irqsave(&consoleloglock, flags);
 176                         HvCall_writeLogBuffer(buf, len);
 177                         spin_unlock_irqrestore(&consoleloglock, flags);
 178                 }
 179
 180                 init_data_event(viochar, pi->lp);
 181
 182                 viochar->len = len;
 183                 viochar->event.xCorrelationToken = pi->seq++;
 184                 viochar->event.xSizeMinus1 =
 185                         offsetof(struct viocharlpevent, data) + len;
 186
 187                 memcpy(viochar->data, buf, len);
 188
 189                 hvrc = HvCallEvent_signalLpEvent(&viochar->event);
 190                 if (hvrc)
 191                         hvlog("\n\rerror sending event! return code %d\n\r",
 192                                 (int)hvrc);
 193                 sent += len;
 194                 count -= len;
 195                 buf += len;
 196         }
 197
 198         vio_free_event_buffer(viomajorsubtype_chario, viochar);
 199 done:
 200         spin_unlock_irqrestore(&consolelock, flags);
 201         return sent;
 202 }
 203
 204 static struct hv_ops hvc_get_put_ops = {
 205         .get_chars = get_chars,
 206         .put_chars = put_chars,
 207 };
 208
 209 static int __devinit hvc_vio_probe(struct vio_dev *vdev,
 210                         const struct vio_device_id *id)
 211 {
 212         struct hvc_struct *hp;
 213         struct port_info *pi;
 214
 215         /* probed with invalid parameters. */
 216         if (!vdev || !id)
 217                 return -EPERM;
 218
 219         if (vdev->unit_address >= VTTY_PORTS)
 220                 return -ENODEV;
 221
 222         pi = &port_info[vdev->unit_address];
 223
 224         hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
 225                         VIOCHAR_MAX_DATA);
 226         if (IS_ERR(hp))
 227                 return PTR_ERR(hp);
 228         pi->hp = hp;
 229         dev_set_drvdata(&vdev->dev, pi);
 230
 231         return 0;
 232 }
 233
 234 static int __devexit hvc_vio_remove(struct vio_dev *vdev)
 235 {
 236         struct port_info *pi = dev_get_drvdata(&vdev->dev);
 237         struct hvc_struct *hp = pi->hp;
 238
 239         return hvc_remove(hp);
 240 }
 241
 242 static struct vio_driver hvc_vio_driver = {
 243         .id_table       = hvc_driver_table,
 244         .probe          = hvc_vio_probe,
 245         .remove         = hvc_vio_remove,
 246         .driver         = {
 247                 .name   = hvc_driver_name,
 248                 .owner  = THIS_MODULE,
 249         }
 250 };
 251
 252 static void hvc_open_event(struct HvLpEvent *event)
 253 {
 254         unsigned long flags;
 255         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
 256         u8 port = cevent->virtual_device;
 257         struct port_info *pi;
 258         int reject = 0;
 259
 260         if (hvlpevent_is_ack(event)) {
 261                 if (port >= VTTY_PORTS)
 262                         return;
 263
 264                 spin_lock_irqsave(&consolelock, flags);
 265
 266                 pi = &port_info[port];
 267                 if (event->xRc == HvLpEvent_Rc_Good) {
 268                         pi->seq = pi->ack = 0;
 269                         /*
 270                          * This line allows connections from the primary
 271                          * partition but once one is connected from the
 272                          * primary partition nothing short of a reboot
 273                          * of linux will allow access from the hosting
 274                          * partition again without a required iSeries fix.
 275                          */
 276                         pi->lp = event->xTargetLp;
 277                 }
 278
 279                 spin_unlock_irqrestore(&consolelock, flags);
 280                 if (event->xRc != HvLpEvent_Rc_Good)
 281                         printk(KERN_WARNING
 282                                "hvc: handle_open_event: event->xRc == (%d).\n",
 283                                event->xRc);
 284
 285                 if (event->xCorrelationToken != 0) {
 286                         atomic_t *aptr= (atomic_t *)event->xCorrelationToken;
 287                         atomic_set(aptr, 1);
 288                 } else
 289                         printk(KERN_WARNING
 290                                "hvc: weird...got open ack without atomic\n");
 291                 return;
 292         }
 293
 294         /* This had better require an ack, otherwise complain */
 295         if (!hvlpevent_need_ack(event)) {
 296                 printk(KERN_WARNING "hvc: viocharopen without ack bit!\n");
 297                 return;
 298         }
 299
 300         spin_lock_irqsave(&consolelock, flags);
 301
 302         /* Make sure this is a good virtual tty */
 303         if (port >= VTTY_PORTS) {
 304                 event->xRc = HvLpEvent_Rc_SubtypeError;
 305                 cevent->subtype_result_code = viorc_openRejected;
 306                 /*
 307                  * Flag state here since we can't printk while holding
 308                  * the consolelock spinlock.
 309                  */
 310                 reject = 1;
 311         } else {
 312                 pi = &port_info[port];
 313                 if ((pi->lp != HvLpIndexInvalid) &&
 314                                 (pi->lp != event->xSourceLp)) {
 315                         /*
 316                          * If this is tty is already connected to a different
 317                          * partition, fail.
 318                          */
 319                         event->xRc = HvLpEvent_Rc_SubtypeError;
 320                         cevent->subtype_result_code = viorc_openRejected;
 321                         reject = 2;
 322                 } else {
 323                         pi->lp = event->xSourceLp;
 324                         event->xRc = HvLpEvent_Rc_Good;
 325                         cevent->subtype_result_code = viorc_good;
 326                         pi->seq = pi->ack = 0;
 327                 }
 328         }
 329
 330         spin_unlock_irqrestore(&consolelock, flags);
 331
 332         if (reject == 1)
 333                 printk(KERN_WARNING "hvc: open rejected: bad virtual tty.\n");
 334         else if (reject == 2)
 335                 printk(KERN_WARNING "hvc: open rejected: console in exclusive "
 336                                 "use by another partition.\n");
 337
 338         /* Return the acknowledgement */
 339         HvCallEvent_ackLpEvent(event);
 340 }
 341
 342 /*
 343  * Handle a close charLpEvent.  This should ONLY be an Interrupt because the
 344  * virtual console should never actually issue a close event to the hypervisor
 345  * because the virtual console never goes away.  A close event coming from the
 346  * hypervisor simply means that there are no client consoles connected to the
 347  * virtual console.
 348  */
 349 static void hvc_close_event(struct HvLpEvent *event)
 350 {
 351         unsigned long flags;
 352         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
 353         u8 port = cevent->virtual_device;
 354
 355         if (!hvlpevent_is_int(event)) {
 356                 printk(KERN_WARNING
 357                         "hvc: got unexpected close acknowlegement\n");
 358                 return;
 359         }
 360
 361         if (port >= VTTY_PORTS) {
 362                 printk(KERN_WARNING
 363                         "hvc: close message from invalid virtual device.\n");
 364                 return;
 365         }
 366
 367         /* For closes, just mark the console partition invalid */
 368         spin_lock_irqsave(&consolelock, flags);
 369
 370         if (port_info[port].lp == event->xSourceLp)
 371                 port_info[port].lp = HvLpIndexInvalid;
 372
 373         spin_unlock_irqrestore(&consolelock, flags);
 374 }
 375
 376 static void hvc_data_event(struct HvLpEvent *event)
 377 {
 378         unsigned long flags;
 379         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
 380         struct port_info *pi;
 381         int n;
 382         u8 port = cevent->virtual_device;
 383
 384         if (port >= VTTY_PORTS) {
 385                 printk(KERN_WARNING "hvc: data on invalid virtual device %d\n",
 386                                 port);
 387                 return;
 388         }
 389         if (cevent->len == 0)
 390                 return;
 391
 392         /*
 393          * Change 05/01/2003 - Ryan Arnold: If a partition other than
 394          * the current exclusive partition tries to send us data
 395          * events then just drop them on the floor because we don't
 396          * want his stinking data.  He isn't authorized to receive
 397          * data because he wasn't the first one to get the console,
 398          * therefore he shouldn't be allowed to send data either.
 399          * This will work without an iSeries fix.
 400          */
 401         pi = &port_info[port];
 402         if (pi->lp != event->xSourceLp)
 403                 return;
 404
 405         spin_lock_irqsave(&consolelock, flags);
 406
 407         n = IN_BUF_SIZE - pi->in_end;
 408         if (n > cevent->len)
 409                 n = cevent->len;
 410         if (n > 0) {
 411                 memcpy(&pi->in_buf[pi->in_end], cevent->data, n);
 412                 pi->in_end += n;
 413         }
 414         spin_unlock_irqrestore(&consolelock, flags);
 415         if (n == 0)
 416                 printk(KERN_WARNING "hvc: input buffer overflow\n");
 417 }
 418
 419 static void hvc_ack_event(struct HvLpEvent *event)
 420 {
 421         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
 422         unsigned long flags;
 423         u8 port = cevent->virtual_device;
 424
 425         if (port >= VTTY_PORTS) {
 426                 printk(KERN_WARNING "hvc: data on invalid virtual device\n");
 427                 return;
 428         }
 429
 430         spin_lock_irqsave(&consolelock, flags);
 431         port_info[port].ack = event->xCorrelationToken;
 432         spin_unlock_irqrestore(&consolelock, flags);
 433 }
 434
 435 static void hvc_config_event(struct HvLpEvent *event)
 436 {
 437         struct viocharlpevent *cevent = (struct viocharlpevent *)event;
 438
 439         if (cevent->data[0] == 0x01)
 440                 printk(KERN_INFO "hvc: window resized to %d: %d: %d: %d\n",
 441                        cevent->data[1], cevent->data[2],
 442                        cevent->data[3], cevent->data[4]);
 443         else
 444                 printk(KERN_WARNING "hvc: unknown config event\n");
 445 }
 446
 447 static void hvc_handle_event(struct HvLpEvent *event)
 448 {
 449         int charminor;
 450
 451         if (event == NULL)
 452                 return;
 453
 454         charminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
 455         switch (charminor) {
 456         case viocharopen:
 457                 hvc_open_event(event);
 458                 break;
 459         case viocharclose:
 460                 hvc_close_event(event);
 461                 break;
 462         case viochardata:
 463                 hvc_data_event(event);
 464                 break;
 465         case viocharack:
 466                 hvc_ack_event(event);
 467                 break;
 468         case viocharconfig:
 469                 hvc_config_event(event);
 470                 break;
 471         default:
 472                 if (hvlpevent_is_int(event) && hvlpevent_need_ack(event)) {
 473                         event->xRc = HvLpEvent_Rc_InvalidSubtype;
 474                         HvCallEvent_ackLpEvent(event);
 475                 }
 476         }
 477 }
 478
 479 static int send_open(HvLpIndex remoteLp, void *sem)
 480 {
 481         return HvCallEvent_signalLpEventFast(remoteLp,
 482                         HvLpEvent_Type_VirtualIo,
 483                         viomajorsubtype_chario | viocharopen,
 484                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 485                         viopath_sourceinst(remoteLp),
 486                         viopath_targetinst(remoteLp),
 487                         (u64)(unsigned long)sem, VIOVERSION << 16,
 488                         0, 0, 0, 0);
 489 }
 490
 491 static int hvc_vio_init(void)
 492 {
 493         atomic_t wait_flag;
 494         int rc;
 495
 496         /* +2 for fudge */
 497         rc = viopath_open(HvLpConfig_getPrimaryLpIndex(),
 498                         viomajorsubtype_chario, VIOCHAR_WINDOW + 2);
 499         if (rc)
 500                 printk(KERN_WARNING "hvc: error opening to primary %d\n", rc);
 501
 502         if (viopath_hostLp == HvLpIndexInvalid)
 503                 vio_set_hostlp();
 504
 505         /*
 506          * And if the primary is not the same as the hosting LP, open to the
 507          * hosting lp
 508          */
 509         if ((viopath_hostLp != HvLpIndexInvalid) &&
 510             (viopath_hostLp != HvLpConfig_getPrimaryLpIndex())) {
 511                 printk(KERN_INFO "hvc: open path to hosting (%d)\n",
 512                                 viopath_hostLp);
 513                 rc = viopath_open(viopath_hostLp, viomajorsubtype_chario,
 514                                 VIOCHAR_WINDOW + 2);    /* +2 for fudge */
 515                 if (rc)
 516                         printk(KERN_WARNING
 517                                 "error opening to partition %d: %d\n",
 518                                 viopath_hostLp, rc);
 519         }
 520
 521         if (vio_setHandler(viomajorsubtype_chario, hvc_handle_event) < 0)
 522                 printk(KERN_WARNING
 523                         "hvc: error seting handler for console events!\n");
 524
 525         /*
 526          * First, try to open the console to the hosting lp.
 527          * Wait on a semaphore for the response.
 528          */
 529         atomic_set(&wait_flag, 0);
 530         if ((viopath_isactive(viopath_hostLp)) &&
 531             (send_open(viopath_hostLp, &wait_flag) == 0)) {
 532                 printk(KERN_INFO "hvc: hosting partition %d\n", viopath_hostLp);
 533                 while (atomic_read(&wait_flag) == 0)
 534                         mb();
 535                 atomic_set(&wait_flag, 0);
 536         }
 537
 538         /*
 539          * If we don't have an active console, try the primary
 540          */
 541         if ((!viopath_isactive(port_info[0].lp)) &&
 542             (viopath_isactive(HvLpConfig_getPrimaryLpIndex())) &&
 543             (send_open(HvLpConfig_getPrimaryLpIndex(), &wait_flag) == 0)) {
 544                 printk(KERN_INFO "hvc: opening console to primary partition\n");
 545                 while (atomic_read(&wait_flag) == 0)
 546                         mb();
 547         }
 548
 549         /* Register as a vio device to receive callbacks */
 550         rc = vio_register_driver(&hvc_vio_driver);
 551
 552         return rc;
 553 }
 554 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
 555
 556 static void hvc_vio_exit(void)
 557 {
 558         vio_unregister_driver(&hvc_vio_driver);
 559 }
 560 module_exit(hvc_vio_exit);
 561
 562 /* the device tree order defines our numbering */
 563 static int hvc_find_vtys(void)
 564 {
 565         struct device_node *vty;
 566         int num_found = 0;
 567
 568         for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
 569                         vty = of_find_node_by_name(vty, "vty")) {
 570                 uint32_t *vtermno;
 571
 572                 /* We have statically defined space for only a certain number
 573                  * of console adapters.
 574                  */
 575                 if ((num_found >= MAX_NR_HVC_CONSOLES) ||
 576                                 (num_found >= VTTY_PORTS))
 577                         break;
 578
 579                 vtermno = (uint32_t *)get_property(vty, "reg", NULL);
 580                 if (!vtermno)
 581                         continue;
 582
 583                 if (!device_is_compatible(vty, "IBM,iSeries-vty"))
 584                         continue;
 585
 586                 if (num_found == 0)
 587                         add_preferred_console("hvc", 0, NULL);
 588                 hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
 589                 ++num_found;
 590         }
 591
 592         return num_found;
 593 }
 594 console_initcall(hvc_find_vtys);