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 = 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 }
 593 console_initcall(hvc_find_vtys);