arch/sparc/kernel/ldc.c

   1 /* ldc.c: Logical Domain Channel link-layer protocol driver.
   2  *
   3  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/export.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/delay.h>
  11 #include <linux/errno.h>
  12 #include <linux/string.h>
  13 #include <linux/scatterlist.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/list.h>
  16 #include <linux/init.h>
  17 #include <linux/bitmap.h>
  18
  19 #include <asm/hypervisor.h>
  20 #include <asm/iommu.h>
  21 #include <asm/page.h>
  22 #include <asm/ldc.h>
  23 #include <asm/mdesc.h>
  24
  25 #define DRV_MODULE_NAME         "ldc"
  26 #define PFX DRV_MODULE_NAME     ": "
  27 #define DRV_MODULE_VERSION      "1.1"
  28 #define DRV_MODULE_RELDATE      "July 22, 2008"
  29
  30 static char version[] __devinitdata =
  31         DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
  32 #define LDC_PACKET_SIZE         64
  33
  34 /* Packet header layout for unreliable and reliable mode frames.
  35  * When in RAW mode, packets are simply straight 64-byte payloads
  36  * with no headers.
  37  */
  38 struct ldc_packet {
  39         u8                      type;
  40 #define LDC_CTRL                0x01
  41 #define LDC_DATA                0x02
  42 #define LDC_ERR                 0x10
  43
  44         u8                      stype;
  45 #define LDC_INFO                0x01
  46 #define LDC_ACK                 0x02
  47 #define LDC_NACK                0x04
  48
  49         u8                      ctrl;
  50 #define LDC_VERS                0x01 /* Link Version            */
  51 #define LDC_RTS                 0x02 /* Request To Send         */
  52 #define LDC_RTR                 0x03 /* Ready To Receive        */
  53 #define LDC_RDX                 0x04 /* Ready for Data eXchange */
  54 #define LDC_CTRL_MSK            0x0f
  55
  56         u8                      env;
  57 #define LDC_LEN                 0x3f
  58 #define LDC_FRAG_MASK           0xc0
  59 #define LDC_START               0x40
  60 #define LDC_STOP                0x80
  61
  62         u32                     seqid;
  63
  64         union {
  65                 u8              u_data[LDC_PACKET_SIZE - 8];
  66                 struct {
  67                         u32     pad;
  68                         u32     ackid;
  69                         u8      r_data[LDC_PACKET_SIZE - 8 - 8];
  70                 } r;
  71         } u;
  72 };
  73
  74 struct ldc_version {
  75         u16 major;
  76         u16 minor;
  77 };
  78
  79 /* Ordered from largest major to lowest.  */
  80 static struct ldc_version ver_arr[] = {
  81         { .major = 1, .minor = 0 },
  82 };
  83
  84 #define LDC_DEFAULT_MTU                 (4 * LDC_PACKET_SIZE)
  85 #define LDC_DEFAULT_NUM_ENTRIES         (PAGE_SIZE / LDC_PACKET_SIZE)
  86
  87 struct ldc_channel;
  88
  89 struct ldc_mode_ops {
  90         int (*write)(struct ldc_channel *, const void *, unsigned int);
  91         int (*read)(struct ldc_channel *, void *, unsigned int);
  92 };
  93
  94 static const struct ldc_mode_ops raw_ops;
  95 static const struct ldc_mode_ops nonraw_ops;
  96 static const struct ldc_mode_ops stream_ops;
  97
  98 int ldom_domaining_enabled;
  99
 100 struct ldc_iommu {
 101         /* Protects arena alloc/free.  */
 102         spinlock_t                      lock;
 103         struct iommu_arena              arena;
 104         struct ldc_mtable_entry         *page_table;
 105 };
 106
 107 struct ldc_channel {
 108         /* Protects all operations that depend upon channel state.  */
 109         spinlock_t                      lock;
 110
 111         unsigned long                   id;
 112
 113         u8                              *mssbuf;
 114         u32                             mssbuf_len;
 115         u32                             mssbuf_off;
 116
 117         struct ldc_packet               *tx_base;
 118         unsigned long                   tx_head;
 119         unsigned long                   tx_tail;
 120         unsigned long                   tx_num_entries;
 121         unsigned long                   tx_ra;
 122
 123         unsigned long                   tx_acked;
 124
 125         struct ldc_packet               *rx_base;
 126         unsigned long                   rx_head;
 127         unsigned long                   rx_tail;
 128         unsigned long                   rx_num_entries;
 129         unsigned long                   rx_ra;
 130
 131         u32                             rcv_nxt;
 132         u32                             snd_nxt;
 133
 134         unsigned long                   chan_state;
 135
 136         struct ldc_channel_config       cfg;
 137         void                            *event_arg;
 138
 139         const struct ldc_mode_ops       *mops;
 140
 141         struct ldc_iommu                iommu;
 142
 143         struct ldc_version              ver;
 144
 145         u8                              hs_state;
 146 #define LDC_HS_CLOSED                   0x00
 147 #define LDC_HS_OPEN                     0x01
 148 #define LDC_HS_GOTVERS                  0x02
 149 #define LDC_HS_SENTRTR                  0x03
 150 #define LDC_HS_GOTRTR                   0x04
 151 #define LDC_HS_COMPLETE                 0x10
 152
 153         u8                              flags;
 154 #define LDC_FLAG_ALLOCED_QUEUES         0x01
 155 #define LDC_FLAG_REGISTERED_QUEUES      0x02
 156 #define LDC_FLAG_REGISTERED_IRQS        0x04
 157 #define LDC_FLAG_RESET                  0x10
 158
 159         u8                              mss;
 160         u8                              state;
 161
 162 #define LDC_IRQ_NAME_MAX                32
 163         char                            rx_irq_name[LDC_IRQ_NAME_MAX];
 164         char                            tx_irq_name[LDC_IRQ_NAME_MAX];
 165
 166         struct hlist_head               mh_list;
 167
 168         struct hlist_node               list;
 169 };
 170
 171 #define ldcdbg(TYPE, f, a...) \
 172 do {    if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
 173                 printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
 174 } while (0)
 175
 176 static const char *state_to_str(u8 state)
 177 {
 178         switch (state) {
 179         case LDC_STATE_INVALID:
 180                 return "INVALID";
 181         case LDC_STATE_INIT:
 182                 return "INIT";
 183         case LDC_STATE_BOUND:
 184                 return "BOUND";
 185         case LDC_STATE_READY:
 186                 return "READY";
 187         case LDC_STATE_CONNECTED:
 188                 return "CONNECTED";
 189         default:
 190                 return "<UNKNOWN>";
 191         }
 192 }
 193
 194 static void ldc_set_state(struct ldc_channel *lp, u8 state)
 195 {
 196         ldcdbg(STATE, "STATE (%s) --> (%s)\n",
 197                state_to_str(lp->state),
 198                state_to_str(state));
 199
 200         lp->state = state;
 201 }
 202
 203 static unsigned long __advance(unsigned long off, unsigned long num_entries)
 204 {
 205         off += LDC_PACKET_SIZE;
 206         if (off == (num_entries * LDC_PACKET_SIZE))
 207                 off = 0;
 208
 209         return off;
 210 }
 211
 212 static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
 213 {
 214         return __advance(off, lp->rx_num_entries);
 215 }
 216
 217 static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
 218 {
 219         return __advance(off, lp->tx_num_entries);
 220 }
 221
 222 static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp,
 223                                                   unsigned long *new_tail)
 224 {
 225         struct ldc_packet *p;
 226         unsigned long t;
 227
 228         t = tx_advance(lp, lp->tx_tail);
 229         if (t == lp->tx_head)
 230                 return NULL;
 231
 232         *new_tail = t;
 233
 234         p = lp->tx_base;
 235         return p + (lp->tx_tail / LDC_PACKET_SIZE);
 236 }
 237
 238 /* When we are in reliable or stream mode, have to track the next packet
 239  * we haven't gotten an ACK for in the TX queue using tx_acked.  We have
 240  * to be careful not to stomp over the queue past that point.  During
 241  * the handshake, we don't have TX data packets pending in the queue
 242  * and that's why handshake_get_tx_packet() need not be mindful of
 243  * lp->tx_acked.
 244  */
 245 static unsigned long head_for_data(struct ldc_channel *lp)
 246 {
 247         if (lp->cfg.mode == LDC_MODE_STREAM)
 248                 return lp->tx_acked;
 249         return lp->tx_head;
 250 }
 251
 252 static int tx_has_space_for(struct ldc_channel *lp, unsigned int size)
 253 {
 254         unsigned long limit, tail, new_tail, diff;
 255         unsigned int mss;
 256
 257         limit = head_for_data(lp);
 258         tail = lp->tx_tail;
 259         new_tail = tx_advance(lp, tail);
 260         if (new_tail == limit)
 261                 return 0;
 262
 263         if (limit > new_tail)
 264                 diff = limit - new_tail;
 265         else
 266                 diff = (limit +
 267                         ((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail));
 268         diff /= LDC_PACKET_SIZE;
 269         mss = lp->mss;
 270
 271         if (diff * mss < size)
 272                 return 0;
 273
 274         return 1;
 275 }
 276
 277 static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp,
 278                                              unsigned long *new_tail)
 279 {
 280         struct ldc_packet *p;
 281         unsigned long h, t;
 282
 283         h = head_for_data(lp);
 284         t = tx_advance(lp, lp->tx_tail);
 285         if (t == h)
 286                 return NULL;
 287
 288         *new_tail = t;
 289
 290         p = lp->tx_base;
 291         return p + (lp->tx_tail / LDC_PACKET_SIZE);
 292 }
 293
 294 static int set_tx_tail(struct ldc_channel *lp, unsigned long tail)
 295 {
 296         unsigned long orig_tail = lp->tx_tail;
 297         int limit = 1000;
 298
 299         lp->tx_tail = tail;
 300         while (limit-- > 0) {
 301                 unsigned long err;
 302
 303                 err = sun4v_ldc_tx_set_qtail(lp->id, tail);
 304                 if (!err)
 305                         return 0;
 306
 307                 if (err != HV_EWOULDBLOCK) {
 308                         lp->tx_tail = orig_tail;
 309                         return -EINVAL;
 310                 }
 311                 udelay(1);
 312         }
 313
 314         lp->tx_tail = orig_tail;
 315         return -EBUSY;
 316 }
 317
 318 /* This just updates the head value in the hypervisor using
 319  * a polling loop with a timeout.  The caller takes care of
 320  * upating software state representing the head change, if any.
 321  */
 322 static int __set_rx_head(struct ldc_channel *lp, unsigned long head)
 323 {
 324         int limit = 1000;
 325
 326         while (limit-- > 0) {
 327                 unsigned long err;
 328
 329                 err = sun4v_ldc_rx_set_qhead(lp->id, head);
 330                 if (!err)
 331                         return 0;
 332
 333                 if (err != HV_EWOULDBLOCK)
 334                         return -EINVAL;
 335
 336                 udelay(1);
 337         }
 338
 339         return -EBUSY;
 340 }
 341
 342 static int send_tx_packet(struct ldc_channel *lp,
 343                           struct ldc_packet *p,
 344                           unsigned long new_tail)
 345 {
 346         BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE)));
 347
 348         return set_tx_tail(lp, new_tail);
 349 }
 350
 351 static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp,
 352                                                  u8 stype, u8 ctrl,
 353                                                  void *data, int dlen,
 354                                                  unsigned long *new_tail)
 355 {
 356         struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail);
 357
 358         if (p) {
 359                 memset(p, 0, sizeof(*p));
 360                 p->type = LDC_CTRL;
 361                 p->stype = stype;
 362                 p->ctrl = ctrl;
 363                 if (data)
 364                         memcpy(p->u.u_data, data, dlen);
 365         }
 366         return p;
 367 }
 368
 369 static int start_handshake(struct ldc_channel *lp)
 370 {
 371         struct ldc_packet *p;
 372         struct ldc_version *ver;
 373         unsigned long new_tail;
 374
 375         ver = &ver_arr[0];
 376
 377         ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n",
 378                ver->major, ver->minor);
 379
 380         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
 381                                    ver, sizeof(*ver), &new_tail);
 382         if (p) {
 383                 int err = send_tx_packet(lp, p, new_tail);
 384                 if (!err)
 385                         lp->flags &= ~LDC_FLAG_RESET;
 386                 return err;
 387         }
 388         return -EBUSY;
 389 }
 390
 391 static int send_version_nack(struct ldc_channel *lp,
 392                              u16 major, u16 minor)
 393 {
 394         struct ldc_packet *p;
 395         struct ldc_version ver;
 396         unsigned long new_tail;
 397
 398         ver.major = major;
 399         ver.minor = minor;
 400
 401         p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS,
 402                                    &ver, sizeof(ver), &new_tail);
 403         if (p) {
 404                 ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n",
 405                        ver.major, ver.minor);
 406
 407                 return send_tx_packet(lp, p, new_tail);
 408         }
 409         return -EBUSY;
 410 }
 411
 412 static int send_version_ack(struct ldc_channel *lp,
 413                             struct ldc_version *vp)
 414 {
 415         struct ldc_packet *p;
 416         unsigned long new_tail;
 417
 418         p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS,
 419                                    vp, sizeof(*vp), &new_tail);
 420         if (p) {
 421                 ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n",
 422                        vp->major, vp->minor);
 423
 424                 return send_tx_packet(lp, p, new_tail);
 425         }
 426         return -EBUSY;
 427 }
 428
 429 static int send_rts(struct ldc_channel *lp)
 430 {
 431         struct ldc_packet *p;
 432         unsigned long new_tail;
 433
 434         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0,
 435                                    &new_tail);
 436         if (p) {
 437                 p->env = lp->cfg.mode;
 438                 p->seqid = 0;
 439                 lp->rcv_nxt = 0;
 440
 441                 ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n",
 442                        p->env, p->seqid);
 443
 444                 return send_tx_packet(lp, p, new_tail);
 445         }
 446         return -EBUSY;
 447 }
 448
 449 static int send_rtr(struct ldc_channel *lp)
 450 {
 451         struct ldc_packet *p;
 452         unsigned long new_tail;
 453
 454         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0,
 455                                    &new_tail);
 456         if (p) {
 457                 p->env = lp->cfg.mode;
 458                 p->seqid = 0;
 459
 460                 ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n",
 461                        p->env, p->seqid);
 462
 463                 return send_tx_packet(lp, p, new_tail);
 464         }
 465         return -EBUSY;
 466 }
 467
 468 static int send_rdx(struct ldc_channel *lp)
 469 {
 470         struct ldc_packet *p;
 471         unsigned long new_tail;
 472
 473         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0,
 474                                    &new_tail);
 475         if (p) {
 476                 p->env = 0;
 477                 p->seqid = ++lp->snd_nxt;
 478                 p->u.r.ackid = lp->rcv_nxt;
 479
 480                 ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n",
 481                        p->env, p->seqid, p->u.r.ackid);
 482
 483                 return send_tx_packet(lp, p, new_tail);
 484         }
 485         return -EBUSY;
 486 }
 487
 488 static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt)
 489 {
 490         struct ldc_packet *p;
 491         unsigned long new_tail;
 492         int err;
 493
 494         p = data_get_tx_packet(lp, &new_tail);
 495         if (!p)
 496                 return -EBUSY;
 497         memset(p, 0, sizeof(*p));
 498         p->type = data_pkt->type;
 499         p->stype = LDC_NACK;
 500         p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK;
 501         p->seqid = lp->snd_nxt + 1;
 502         p->u.r.ackid = lp->rcv_nxt;
 503
 504         ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n",
 505                p->type, p->ctrl, p->seqid, p->u.r.ackid);
 506
 507         err = send_tx_packet(lp, p, new_tail);
 508         if (!err)
 509                 lp->snd_nxt++;
 510
 511         return err;
 512 }
 513
 514 static int ldc_abort(struct ldc_channel *lp)
 515 {
 516         unsigned long hv_err;
 517
 518         ldcdbg(STATE, "ABORT\n");
 519
 520         /* We report but do not act upon the hypervisor errors because
 521          * there really isn't much we can do if they fail at this point.
 522          */
 523         hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
 524         if (hv_err)
 525                 printk(KERN_ERR PFX "ldc_abort: "
 526                        "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
 527                        lp->id, lp->tx_ra, lp->tx_num_entries, hv_err);
 528
 529         hv_err = sun4v_ldc_tx_get_state(lp->id,
 530                                         &lp->tx_head,
 531                                         &lp->tx_tail,
 532                                         &lp->chan_state);
 533         if (hv_err)
 534                 printk(KERN_ERR PFX "ldc_abort: "
 535                        "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n",
 536                        lp->id, hv_err);
 537
 538         hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
 539         if (hv_err)
 540                 printk(KERN_ERR PFX "ldc_abort: "
 541                        "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
 542                        lp->id, lp->rx_ra, lp->rx_num_entries, hv_err);
 543
 544         /* Refetch the RX queue state as well, because we could be invoked
 545          * here in the queue processing context.
 546          */
 547         hv_err = sun4v_ldc_rx_get_state(lp->id,
 548                                         &lp->rx_head,
 549                                         &lp->rx_tail,
 550                                         &lp->chan_state);
 551         if (hv_err)
 552                 printk(KERN_ERR PFX "ldc_abort: "
 553                        "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n",
 554                        lp->id, hv_err);
 555
 556         return -ECONNRESET;
 557 }
 558
 559 static struct ldc_version *find_by_major(u16 major)
 560 {
 561         struct ldc_version *ret = NULL;
 562         int i;
 563
 564         for (i = 0; i < ARRAY_SIZE(ver_arr); i++) {
 565                 struct ldc_version *v = &ver_arr[i];
 566                 if (v->major <= major) {
 567                         ret = v;
 568                         break;
 569                 }
 570         }
 571         return ret;
 572 }
 573
 574 static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp)
 575 {
 576         struct ldc_version *vap;
 577         int err;
 578
 579         ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n",
 580                vp->major, vp->minor);
 581
 582         if (lp->hs_state == LDC_HS_GOTVERS) {
 583                 lp->hs_state = LDC_HS_OPEN;
 584                 memset(&lp->ver, 0, sizeof(lp->ver));
 585         }
 586
 587         vap = find_by_major(vp->major);
 588         if (!vap) {
 589                 err = send_version_nack(lp, 0, 0);
 590         } else if (vap->major != vp->major) {
 591                 err = send_version_nack(lp, vap->major, vap->minor);
 592         } else {
 593                 struct ldc_version ver = *vp;
 594                 if (ver.minor > vap->minor)
 595                         ver.minor = vap->minor;
 596                 err = send_version_ack(lp, &ver);
 597                 if (!err) {
 598                         lp->ver = ver;
 599                         lp->hs_state = LDC_HS_GOTVERS;
 600                 }
 601         }
 602         if (err)
 603                 return ldc_abort(lp);
 604
 605         return 0;
 606 }
 607
 608 static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp)
 609 {
 610         ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n",
 611                vp->major, vp->minor);
 612
 613         if (lp->hs_state == LDC_HS_GOTVERS) {
 614                 if (lp->ver.major != vp->major ||
 615                     lp->ver.minor != vp->minor)
 616                         return ldc_abort(lp);
 617         } else {
 618                 lp->ver = *vp;
 619                 lp->hs_state = LDC_HS_GOTVERS;
 620         }
 621         if (send_rts(lp))
 622                 return ldc_abort(lp);
 623         return 0;
 624 }
 625
 626 static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp)
 627 {
 628         struct ldc_version *vap;
 629         struct ldc_packet *p;
 630         unsigned long new_tail;
 631
 632         if (vp->major == 0 && vp->minor == 0)
 633                 return ldc_abort(lp);
 634
 635         vap = find_by_major(vp->major);
 636         if (!vap)
 637                 return ldc_abort(lp);
 638
 639         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
 640                                            vap, sizeof(*vap),
 641                                            &new_tail);
 642         if (!p)
 643                 return ldc_abort(lp);
 644
 645         return send_tx_packet(lp, p, new_tail);
 646 }
 647
 648 static int process_version(struct ldc_channel *lp,
 649                            struct ldc_packet *p)
 650 {
 651         struct ldc_version *vp;
 652
 653         vp = (struct ldc_version *) p->u.u_data;
 654
 655         switch (p->stype) {
 656         case LDC_INFO:
 657                 return process_ver_info(lp, vp);
 658
 659         case LDC_ACK:
 660                 return process_ver_ack(lp, vp);
 661
 662         case LDC_NACK:
 663                 return process_ver_nack(lp, vp);
 664
 665         default:
 666                 return ldc_abort(lp);
 667         }
 668 }
 669
 670 static int process_rts(struct ldc_channel *lp,
 671                        struct ldc_packet *p)
 672 {
 673         ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n",
 674                p->stype, p->seqid, p->env);
 675
 676         if (p->stype     != LDC_INFO       ||
 677             lp->hs_state != LDC_HS_GOTVERS ||
 678             p->env       != lp->cfg.mode)
 679                 return ldc_abort(lp);
 680
 681         lp->snd_nxt = p->seqid;
 682         lp->rcv_nxt = p->seqid;
 683         lp->hs_state = LDC_HS_SENTRTR;
 684         if (send_rtr(lp))
 685                 return ldc_abort(lp);
 686
 687         return 0;
 688 }
 689
 690 static int process_rtr(struct ldc_channel *lp,
 691                        struct ldc_packet *p)
 692 {
 693         ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n",
 694                p->stype, p->seqid, p->env);
 695
 696         if (p->stype     != LDC_INFO ||
 697             p->env       != lp->cfg.mode)
 698                 return ldc_abort(lp);
 699
 700         lp->snd_nxt = p->seqid;
 701         lp->hs_state = LDC_HS_COMPLETE;
 702         ldc_set_state(lp, LDC_STATE_CONNECTED);
 703         send_rdx(lp);
 704
 705         return LDC_EVENT_UP;
 706 }
 707
 708 static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
 709 {
 710         return lp->rcv_nxt + 1 == seqid;
 711 }
 712
 713 static int process_rdx(struct ldc_channel *lp,
 714                        struct ldc_packet *p)
 715 {
 716         ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n",
 717                p->stype, p->seqid, p->env, p->u.r.ackid);
 718
 719         if (p->stype != LDC_INFO ||
 720             !(rx_seq_ok(lp, p->seqid)))
 721                 return ldc_abort(lp);
 722
 723         lp->rcv_nxt = p->seqid;
 724
 725         lp->hs_state = LDC_HS_COMPLETE;
 726         ldc_set_state(lp, LDC_STATE_CONNECTED);
 727
 728         return LDC_EVENT_UP;
 729 }
 730
 731 static int process_control_frame(struct ldc_channel *lp,
 732                                  struct ldc_packet *p)
 733 {
 734         switch (p->ctrl) {
 735         case LDC_VERS:
 736                 return process_version(lp, p);
 737
 738         case LDC_RTS:
 739                 return process_rts(lp, p);
 740
 741         case LDC_RTR:
 742                 return process_rtr(lp, p);
 743
 744         case LDC_RDX:
 745                 return process_rdx(lp, p);
 746
 747         default:
 748                 return ldc_abort(lp);
 749         }
 750 }
 751
 752 static int process_error_frame(struct ldc_channel *lp,
 753                                struct ldc_packet *p)
 754 {
 755         return ldc_abort(lp);
 756 }
 757
 758 static int process_data_ack(struct ldc_channel *lp,
 759                             struct ldc_packet *ack)
 760 {
 761         unsigned long head = lp->tx_acked;
 762         u32 ackid = ack->u.r.ackid;
 763
 764         while (1) {
 765                 struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE);
 766
 767                 head = tx_advance(lp, head);
 768
 769                 if (p->seqid == ackid) {
 770                         lp->tx_acked = head;
 771                         return 0;
 772                 }
 773                 if (head == lp->tx_tail)
 774                         return ldc_abort(lp);
 775         }
 776
 777         return 0;
 778 }
 779
 780 static void send_events(struct ldc_channel *lp, unsigned int event_mask)
 781 {
 782         if (event_mask & LDC_EVENT_RESET)
 783                 lp->cfg.event(lp->event_arg, LDC_EVENT_RESET);
 784         if (event_mask & LDC_EVENT_UP)
 785                 lp->cfg.event(lp->event_arg, LDC_EVENT_UP);
 786         if (event_mask & LDC_EVENT_DATA_READY)
 787                 lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
 788 }
 789
 790 static irqreturn_t ldc_rx(int irq, void *dev_id)
 791 {
 792         struct ldc_channel *lp = dev_id;
 793         unsigned long orig_state, flags;
 794         unsigned int event_mask;
 795
 796         spin_lock_irqsave(&lp->lock, flags);
 797
 798         orig_state = lp->chan_state;
 799
 800         /* We should probably check for hypervisor errors here and
 801          * reset the LDC channel if we get one.
 802          */
 803         sun4v_ldc_rx_get_state(lp->id,
 804                                &lp->rx_head,
 805                                &lp->rx_tail,
 806                                &lp->chan_state);
 807
 808         ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
 809                orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
 810
 811         event_mask = 0;
 812
 813         if (lp->cfg.mode == LDC_MODE_RAW &&
 814             lp->chan_state == LDC_CHANNEL_UP) {
 815                 lp->hs_state = LDC_HS_COMPLETE;
 816                 ldc_set_state(lp, LDC_STATE_CONNECTED);
 817
 818                 event_mask |= LDC_EVENT_UP;
 819
 820                 orig_state = lp->chan_state;
 821         }
 822
 823         /* If we are in reset state, flush the RX queue and ignore
 824          * everything.
 825          */
 826         if (lp->flags & LDC_FLAG_RESET) {
 827                 (void) __set_rx_head(lp, lp->rx_tail);
 828                 goto out;
 829         }
 830
 831         /* Once we finish the handshake, we let the ldc_read()
 832          * paths do all of the control frame and state management.
 833          * Just trigger the callback.
 834          */
 835         if (lp->hs_state == LDC_HS_COMPLETE) {
 836 handshake_complete:
 837                 if (lp->chan_state != orig_state) {
 838                         unsigned int event = LDC_EVENT_RESET;
 839
 840                         if (lp->chan_state == LDC_CHANNEL_UP)
 841                                 event = LDC_EVENT_UP;
 842
 843                         event_mask |= event;
 844                 }
 845                 if (lp->rx_head != lp->rx_tail)
 846                         event_mask |= LDC_EVENT_DATA_READY;
 847
 848                 goto out;
 849         }
 850
 851         if (lp->chan_state != orig_state)
 852                 goto out;
 853
 854         while (lp->rx_head != lp->rx_tail) {
 855                 struct ldc_packet *p;
 856                 unsigned long new;
 857                 int err;
 858
 859                 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
 860
 861                 switch (p->type) {
 862                 case LDC_CTRL:
 863                         err = process_control_frame(lp, p);
 864                         if (err > 0)
 865                                 event_mask |= err;
 866                         break;
 867
 868                 case LDC_DATA:
 869                         event_mask |= LDC_EVENT_DATA_READY;
 870                         err = 0;
 871                         break;
 872
 873                 case LDC_ERR:
 874                         err = process_error_frame(lp, p);
 875                         break;
 876
 877                 default:
 878                         err = ldc_abort(lp);
 879                         break;
 880                 }
 881
 882                 if (err < 0)
 883                         break;
 884
 885                 new = lp->rx_head;
 886                 new += LDC_PACKET_SIZE;
 887                 if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
 888                         new = 0;
 889                 lp->rx_head = new;
 890
 891                 err = __set_rx_head(lp, new);
 892                 if (err < 0) {
 893                         (void) ldc_abort(lp);
 894                         break;
 895                 }
 896                 if (lp->hs_state == LDC_HS_COMPLETE)
 897                         goto handshake_complete;
 898         }
 899
 900 out:
 901         spin_unlock_irqrestore(&lp->lock, flags);
 902
 903         send_events(lp, event_mask);
 904
 905         return IRQ_HANDLED;
 906 }
 907
 908 static irqreturn_t ldc_tx(int irq, void *dev_id)
 909 {
 910         struct ldc_channel *lp = dev_id;
 911         unsigned long flags, orig_state;
 912         unsigned int event_mask = 0;
 913
 914         spin_lock_irqsave(&lp->lock, flags);
 915
 916         orig_state = lp->chan_state;
 917
 918         /* We should probably check for hypervisor errors here and
 919          * reset the LDC channel if we get one.
 920          */
 921         sun4v_ldc_tx_get_state(lp->id,
 922                                &lp->tx_head,
 923                                &lp->tx_tail,
 924                                &lp->chan_state);
 925
 926         ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
 927                orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
 928
 929         if (lp->cfg.mode == LDC_MODE_RAW &&
 930             lp->chan_state == LDC_CHANNEL_UP) {
 931                 lp->hs_state = LDC_HS_COMPLETE;
 932                 ldc_set_state(lp, LDC_STATE_CONNECTED);
 933
 934                 event_mask |= LDC_EVENT_UP;
 935         }
 936
 937         spin_unlock_irqrestore(&lp->lock, flags);
 938
 939         send_events(lp, event_mask);
 940
 941         return IRQ_HANDLED;
 942 }
 943
 944 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
 945  * XXX that addition and removal from the ldc_channel_list has
 946  * XXX atomicity, otherwise the __ldc_channel_exists() check is
 947  * XXX totally pointless as another thread can slip into ldc_alloc()
 948  * XXX and add a channel with the same ID.  There also needs to be
 949  * XXX a spinlock for ldc_channel_list.
 950  */
 951 static HLIST_HEAD(ldc_channel_list);
 952
 953 static int __ldc_channel_exists(unsigned long id)
 954 {
 955         struct ldc_channel *lp;
 956         struct hlist_node *n;
 957
 958         hlist_for_each_entry(lp, n, &ldc_channel_list, list) {
 959                 if (lp->id == id)
 960                         return 1;
 961         }
 962         return 0;
 963 }
 964
 965 static int alloc_queue(const char *name, unsigned long num_entries,
 966                        struct ldc_packet **base, unsigned long *ra)
 967 {
 968         unsigned long size, order;
 969         void *q;
 970
 971         size = num_entries * LDC_PACKET_SIZE;
 972         order = get_order(size);
 973
 974         q = (void *) __get_free_pages(GFP_KERNEL, order);
 975         if (!q) {
 976                 printk(KERN_ERR PFX "Alloc of %s queue failed with "
 977                        "size=%lu order=%lu\n", name, size, order);
 978                 return -ENOMEM;
 979         }
 980
 981         memset(q, 0, PAGE_SIZE << order);
 982
 983         *base = q;
 984         *ra = __pa(q);
 985
 986         return 0;
 987 }
 988
 989 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
 990 {
 991         unsigned long size, order;
 992
 993         if (!q)
 994                 return;
 995
 996         size = num_entries * LDC_PACKET_SIZE;
 997         order = get_order(size);
 998
 999         free_pages((unsigned long)q, order);
1000 }
1001
1002 /* XXX Make this configurable... XXX */
1003 #define LDC_IOTABLE_SIZE        (8 * 1024)
1004
1005 static int ldc_iommu_init(struct ldc_channel *lp)
1006 {
1007         unsigned long sz, num_tsb_entries, tsbsize, order;
1008         struct ldc_iommu *iommu = &lp->iommu;
1009         struct ldc_mtable_entry *table;
1010         unsigned long hv_err;
1011         int err;
1012
1013         num_tsb_entries = LDC_IOTABLE_SIZE;
1014         tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1015
1016         spin_lock_init(&iommu->lock);
1017
1018         sz = num_tsb_entries / 8;
1019         sz = (sz + 7UL) & ~7UL;
1020         iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1021         if (!iommu->arena.map) {
1022                 printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1023                 return -ENOMEM;
1024         }
1025
1026         iommu->arena.limit = num_tsb_entries;
1027
1028         order = get_order(tsbsize);
1029
1030         table = (struct ldc_mtable_entry *)
1031                 __get_free_pages(GFP_KERNEL, order);
1032         err = -ENOMEM;
1033         if (!table) {
1034                 printk(KERN_ERR PFX "Alloc of MTE table failed, "
1035                        "size=%lu order=%lu\n", tsbsize, order);
1036                 goto out_free_map;
1037         }
1038
1039         memset(table, 0, PAGE_SIZE << order);
1040
1041         iommu->page_table = table;
1042
1043         hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1044                                          num_tsb_entries);
1045         err = -EINVAL;
1046         if (hv_err)
1047                 goto out_free_table;
1048
1049         return 0;
1050
1051 out_free_table:
1052         free_pages((unsigned long) table, order);
1053         iommu->page_table = NULL;
1054
1055 out_free_map:
1056         kfree(iommu->arena.map);
1057         iommu->arena.map = NULL;
1058
1059         return err;
1060 }
1061
1062 static void ldc_iommu_release(struct ldc_channel *lp)
1063 {
1064         struct ldc_iommu *iommu = &lp->iommu;
1065         unsigned long num_tsb_entries, tsbsize, order;
1066
1067         (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1068
1069         num_tsb_entries = iommu->arena.limit;
1070         tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1071         order = get_order(tsbsize);
1072
1073         free_pages((unsigned long) iommu->page_table, order);
1074         iommu->page_table = NULL;
1075
1076         kfree(iommu->arena.map);
1077         iommu->arena.map = NULL;
1078 }
1079
1080 struct ldc_channel *ldc_alloc(unsigned long id,
1081                               const struct ldc_channel_config *cfgp,
1082                               void *event_arg)
1083 {
1084         struct ldc_channel *lp;
1085         const struct ldc_mode_ops *mops;
1086         unsigned long dummy1, dummy2, hv_err;
1087         u8 mss, *mssbuf;
1088         int err;
1089
1090         err = -ENODEV;
1091         if (!ldom_domaining_enabled)
1092                 goto out_err;
1093
1094         err = -EINVAL;
1095         if (!cfgp)
1096                 goto out_err;
1097
1098         switch (cfgp->mode) {
1099         case LDC_MODE_RAW:
1100                 mops = &raw_ops;
1101                 mss = LDC_PACKET_SIZE;
1102                 break;
1103
1104         case LDC_MODE_UNRELIABLE:
1105                 mops = &nonraw_ops;
1106                 mss = LDC_PACKET_SIZE - 8;
1107                 break;
1108
1109         case LDC_MODE_STREAM:
1110                 mops = &stream_ops;
1111                 mss = LDC_PACKET_SIZE - 8 - 8;
1112                 break;
1113
1114         default:
1115                 goto out_err;
1116         }
1117
1118         if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1119                 goto out_err;
1120
1121         hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1122         err = -ENODEV;
1123         if (hv_err == HV_ECHANNEL)
1124                 goto out_err;
1125
1126         err = -EEXIST;
1127         if (__ldc_channel_exists(id))
1128                 goto out_err;
1129
1130         mssbuf = NULL;
1131
1132         lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1133         err = -ENOMEM;
1134         if (!lp)
1135                 goto out_err;
1136
1137         spin_lock_init(&lp->lock);
1138
1139         lp->id = id;
1140
1141         err = ldc_iommu_init(lp);
1142         if (err)
1143                 goto out_free_ldc;
1144
1145         lp->mops = mops;
1146         lp->mss = mss;
1147
1148         lp->cfg = *cfgp;
1149         if (!lp->cfg.mtu)
1150                 lp->cfg.mtu = LDC_DEFAULT_MTU;
1151
1152         if (lp->cfg.mode == LDC_MODE_STREAM) {
1153                 mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1154                 if (!mssbuf) {
1155                         err = -ENOMEM;
1156                         goto out_free_iommu;
1157                 }
1158                 lp->mssbuf = mssbuf;
1159         }
1160
1161         lp->event_arg = event_arg;
1162
1163         /* XXX allow setting via ldc_channel_config to override defaults
1164          * XXX or use some formula based upon mtu
1165          */
1166         lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1167         lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1168
1169         err = alloc_queue("TX", lp->tx_num_entries,
1170                           &lp->tx_base, &lp->tx_ra);
1171         if (err)
1172                 goto out_free_mssbuf;
1173
1174         err = alloc_queue("RX", lp->rx_num_entries,
1175                           &lp->rx_base, &lp->rx_ra);
1176         if (err)
1177                 goto out_free_txq;
1178
1179         lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1180
1181         lp->hs_state = LDC_HS_CLOSED;
1182         ldc_set_state(lp, LDC_STATE_INIT);
1183
1184         INIT_HLIST_NODE(&lp->list);
1185         hlist_add_head(&lp->list, &ldc_channel_list);
1186
1187         INIT_HLIST_HEAD(&lp->mh_list);
1188
1189         return lp;
1190
1191 out_free_txq:
1192         free_queue(lp->tx_num_entries, lp->tx_base);
1193
1194 out_free_mssbuf:
1195         kfree(mssbuf);
1196
1197 out_free_iommu:
1198         ldc_iommu_release(lp);
1199
1200 out_free_ldc:
1201         kfree(lp);
1202
1203 out_err:
1204         return ERR_PTR(err);
1205 }
1206 EXPORT_SYMBOL(ldc_alloc);
1207
1208 void ldc_free(struct ldc_channel *lp)
1209 {
1210         if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1211                 free_irq(lp->cfg.rx_irq, lp);
1212                 free_irq(lp->cfg.tx_irq, lp);
1213         }
1214
1215         if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1216                 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1217                 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1218                 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1219         }
1220         if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1221                 free_queue(lp->tx_num_entries, lp->tx_base);
1222                 free_queue(lp->rx_num_entries, lp->rx_base);
1223                 lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1224         }
1225
1226         hlist_del(&lp->list);
1227
1228         kfree(lp->mssbuf);
1229
1230         ldc_iommu_release(lp);
1231
1232         kfree(lp);
1233 }
1234 EXPORT_SYMBOL(ldc_free);
1235
1236 /* Bind the channel.  This registers the LDC queues with
1237  * the hypervisor and puts the channel into a pseudo-listening
1238  * state.  This does not initiate a handshake, ldc_connect() does
1239  * that.
1240  */
1241 int ldc_bind(struct ldc_channel *lp, const char *name)
1242 {
1243         unsigned long hv_err, flags;
1244         int err = -EINVAL;
1245
1246         if (!name ||
1247             (lp->state != LDC_STATE_INIT))
1248                 return -EINVAL;
1249
1250         snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1251         snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1252
1253         err = request_irq(lp->cfg.rx_irq, ldc_rx, IRQF_DISABLED,
1254                           lp->rx_irq_name, lp);
1255         if (err)
1256                 return err;
1257
1258         err = request_irq(lp->cfg.tx_irq, ldc_tx, IRQF_DISABLED,
1259                           lp->tx_irq_name, lp);
1260         if (err) {
1261                 free_irq(lp->cfg.rx_irq, lp);
1262                 return err;
1263         }
1264
1265
1266         spin_lock_irqsave(&lp->lock, flags);
1267
1268         enable_irq(lp->cfg.rx_irq);
1269         enable_irq(lp->cfg.tx_irq);
1270
1271         lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1272
1273         err = -ENODEV;
1274         hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1275         if (hv_err)
1276                 goto out_free_irqs;
1277
1278         hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1279         if (hv_err)
1280                 goto out_free_irqs;
1281
1282         hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1283         if (hv_err)
1284                 goto out_unmap_tx;
1285
1286         hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1287         if (hv_err)
1288                 goto out_unmap_tx;
1289
1290         lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1291
1292         hv_err = sun4v_ldc_tx_get_state(lp->id,
1293                                         &lp->tx_head,
1294                                         &lp->tx_tail,
1295                                         &lp->chan_state);
1296         err = -EBUSY;
1297         if (hv_err)
1298                 goto out_unmap_rx;
1299
1300         lp->tx_acked = lp->tx_head;
1301
1302         lp->hs_state = LDC_HS_OPEN;
1303         ldc_set_state(lp, LDC_STATE_BOUND);
1304
1305         spin_unlock_irqrestore(&lp->lock, flags);
1306
1307         return 0;
1308
1309 out_unmap_rx:
1310         lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1311         sun4v_ldc_rx_qconf(lp->id, 0, 0);
1312
1313 out_unmap_tx:
1314         sun4v_ldc_tx_qconf(lp->id, 0, 0);
1315
1316 out_free_irqs:
1317         lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1318         free_irq(lp->cfg.tx_irq, lp);
1319         free_irq(lp->cfg.rx_irq, lp);
1320
1321         spin_unlock_irqrestore(&lp->lock, flags);
1322
1323         return err;
1324 }
1325 EXPORT_SYMBOL(ldc_bind);
1326
1327 int ldc_connect(struct ldc_channel *lp)
1328 {
1329         unsigned long flags;
1330         int err;
1331
1332         if (lp->cfg.mode == LDC_MODE_RAW)
1333                 return -EINVAL;
1334
1335         spin_lock_irqsave(&lp->lock, flags);
1336
1337         if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1338             !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1339             lp->hs_state != LDC_HS_OPEN)
1340                 err = -EINVAL;
1341         else
1342                 err = start_handshake(lp);
1343
1344         spin_unlock_irqrestore(&lp->lock, flags);
1345
1346         return err;
1347 }
1348 EXPORT_SYMBOL(ldc_connect);
1349
1350 int ldc_disconnect(struct ldc_channel *lp)
1351 {
1352         unsigned long hv_err, flags;
1353         int err;
1354
1355         if (lp->cfg.mode == LDC_MODE_RAW)
1356                 return -EINVAL;
1357
1358         if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1359             !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1360                 return -EINVAL;
1361
1362         spin_lock_irqsave(&lp->lock, flags);
1363
1364         err = -ENODEV;
1365         hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1366         if (hv_err)
1367                 goto out_err;
1368
1369         hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1370         if (hv_err)
1371                 goto out_err;
1372
1373         hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1374         if (hv_err)
1375                 goto out_err;
1376
1377         hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1378         if (hv_err)
1379                 goto out_err;
1380
1381         ldc_set_state(lp, LDC_STATE_BOUND);
1382         lp->hs_state = LDC_HS_OPEN;
1383         lp->flags |= LDC_FLAG_RESET;
1384
1385         spin_unlock_irqrestore(&lp->lock, flags);
1386
1387         return 0;
1388
1389 out_err:
1390         sun4v_ldc_tx_qconf(lp->id, 0, 0);
1391         sun4v_ldc_rx_qconf(lp->id, 0, 0);
1392         free_irq(lp->cfg.tx_irq, lp);
1393         free_irq(lp->cfg.rx_irq, lp);
1394         lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1395                        LDC_FLAG_REGISTERED_QUEUES);
1396         ldc_set_state(lp, LDC_STATE_INIT);
1397
1398         spin_unlock_irqrestore(&lp->lock, flags);
1399
1400         return err;
1401 }
1402 EXPORT_SYMBOL(ldc_disconnect);
1403
1404 int ldc_state(struct ldc_channel *lp)
1405 {
1406         return lp->state;
1407 }
1408 EXPORT_SYMBOL(ldc_state);
1409
1410 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1411 {
1412         struct ldc_packet *p;
1413         unsigned long new_tail;
1414         int err;
1415
1416         if (size > LDC_PACKET_SIZE)
1417                 return -EMSGSIZE;
1418
1419         p = data_get_tx_packet(lp, &new_tail);
1420         if (!p)
1421                 return -EAGAIN;
1422
1423         memcpy(p, buf, size);
1424
1425         err = send_tx_packet(lp, p, new_tail);
1426         if (!err)
1427                 err = size;
1428
1429         return err;
1430 }
1431
1432 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1433 {
1434         struct ldc_packet *p;
1435         unsigned long hv_err, new;
1436         int err;
1437
1438         if (size < LDC_PACKET_SIZE)
1439                 return -EINVAL;
1440
1441         hv_err = sun4v_ldc_rx_get_state(lp->id,
1442                                         &lp->rx_head,
1443                                         &lp->rx_tail,
1444                                         &lp->chan_state);
1445         if (hv_err)
1446                 return ldc_abort(lp);
1447
1448         if (lp->chan_state == LDC_CHANNEL_DOWN ||
1449             lp->chan_state == LDC_CHANNEL_RESETTING)
1450                 return -ECONNRESET;
1451
1452         if (lp->rx_head == lp->rx_tail)
1453                 return 0;
1454
1455         p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1456         memcpy(buf, p, LDC_PACKET_SIZE);
1457
1458         new = rx_advance(lp, lp->rx_head);
1459         lp->rx_head = new;
1460
1461         err = __set_rx_head(lp, new);
1462         if (err < 0)
1463                 err = -ECONNRESET;
1464         else
1465                 err = LDC_PACKET_SIZE;
1466
1467         return err;
1468 }
1469
1470 static const struct ldc_mode_ops raw_ops = {
1471         .write          =       write_raw,
1472         .read           =       read_raw,
1473 };
1474
1475 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1476                         unsigned int size)
1477 {
1478         unsigned long hv_err, tail;
1479         unsigned int copied;
1480         u32 seq;
1481         int err;
1482
1483         hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1484                                         &lp->chan_state);
1485         if (unlikely(hv_err))
1486                 return -EBUSY;
1487
1488         if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1489                 return ldc_abort(lp);
1490
1491         if (!tx_has_space_for(lp, size))
1492                 return -EAGAIN;
1493
1494         seq = lp->snd_nxt;
1495         copied = 0;
1496         tail = lp->tx_tail;
1497         while (copied < size) {
1498                 struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1499                 u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1500                             p->u.u_data :
1501                             p->u.r.r_data);
1502                 int data_len;
1503
1504                 p->type = LDC_DATA;
1505                 p->stype = LDC_INFO;
1506                 p->ctrl = 0;
1507
1508                 data_len = size - copied;
1509                 if (data_len > lp->mss)
1510                         data_len = lp->mss;
1511
1512                 BUG_ON(data_len > LDC_LEN);
1513
1514                 p->env = (data_len |
1515                           (copied == 0 ? LDC_START : 0) |
1516                           (data_len == size - copied ? LDC_STOP : 0));
1517
1518                 p->seqid = ++seq;
1519
1520                 ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1521                        p->type,
1522                        p->stype,
1523                        p->ctrl,
1524                        p->env,
1525                        p->seqid);
1526
1527                 memcpy(data, buf, data_len);
1528                 buf += data_len;
1529                 copied += data_len;
1530
1531                 tail = tx_advance(lp, tail);
1532         }
1533
1534         err = set_tx_tail(lp, tail);
1535         if (!err) {
1536                 lp->snd_nxt = seq;
1537                 err = size;
1538         }
1539
1540         return err;
1541 }
1542
1543 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1544                       struct ldc_packet *first_frag)
1545 {
1546         int err;
1547
1548         if (first_frag)
1549                 lp->rcv_nxt = first_frag->seqid - 1;
1550
1551         err = send_data_nack(lp, p);
1552         if (err)
1553                 return err;
1554
1555         err = __set_rx_head(lp, lp->rx_tail);
1556         if (err < 0)
1557                 return ldc_abort(lp);
1558
1559         return 0;
1560 }
1561
1562 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1563 {
1564         if (p->stype & LDC_ACK) {
1565                 int err = process_data_ack(lp, p);
1566                 if (err)
1567                         return err;
1568         }
1569         if (p->stype & LDC_NACK)
1570                 return ldc_abort(lp);
1571
1572         return 0;
1573 }
1574
1575 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1576 {
1577         unsigned long dummy;
1578         int limit = 1000;
1579
1580         ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1581                cur_head, lp->rx_head, lp->rx_tail);
1582         while (limit-- > 0) {
1583                 unsigned long hv_err;
1584
1585                 hv_err = sun4v_ldc_rx_get_state(lp->id,
1586                                                 &dummy,
1587                                                 &lp->rx_tail,
1588                                                 &lp->chan_state);
1589                 if (hv_err)
1590                         return ldc_abort(lp);
1591
1592                 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1593                     lp->chan_state == LDC_CHANNEL_RESETTING)
1594                         return -ECONNRESET;
1595
1596                 if (cur_head != lp->rx_tail) {
1597                         ldcdbg(DATA, "DATA WAIT DONE "
1598                                "head[%lx] tail[%lx] chan_state[%lx]\n",
1599                                dummy, lp->rx_tail, lp->chan_state);
1600                         return 0;
1601                 }
1602
1603                 udelay(1);
1604         }
1605         return -EAGAIN;
1606 }
1607
1608 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1609 {
1610         int err = __set_rx_head(lp, head);
1611
1612         if (err < 0)
1613                 return ldc_abort(lp);
1614
1615         lp->rx_head = head;
1616         return 0;
1617 }
1618
1619 static void send_data_ack(struct ldc_channel *lp)
1620 {
1621         unsigned long new_tail;
1622         struct ldc_packet *p;
1623
1624         p = data_get_tx_packet(lp, &new_tail);
1625         if (likely(p)) {
1626                 int err;
1627
1628                 memset(p, 0, sizeof(*p));
1629                 p->type = LDC_DATA;
1630                 p->stype = LDC_ACK;
1631                 p->ctrl = 0;
1632                 p->seqid = lp->snd_nxt + 1;
1633                 p->u.r.ackid = lp->rcv_nxt;
1634
1635                 err = send_tx_packet(lp, p, new_tail);
1636                 if (!err)
1637                         lp->snd_nxt++;
1638         }
1639 }
1640
1641 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1642 {
1643         struct ldc_packet *first_frag;
1644         unsigned long hv_err, new;
1645         int err, copied;
1646
1647         hv_err = sun4v_ldc_rx_get_state(lp->id,
1648                                         &lp->rx_head,
1649                                         &lp->rx_tail,
1650                                         &lp->chan_state);
1651         if (hv_err)
1652                 return ldc_abort(lp);
1653
1654         if (lp->chan_state == LDC_CHANNEL_DOWN ||
1655             lp->chan_state == LDC_CHANNEL_RESETTING)
1656                 return -ECONNRESET;
1657
1658         if (lp->rx_head == lp->rx_tail)
1659                 return 0;
1660
1661         first_frag = NULL;
1662         copied = err = 0;
1663         new = lp->rx_head;
1664         while (1) {
1665                 struct ldc_packet *p;
1666                 int pkt_len;
1667
1668                 BUG_ON(new == lp->rx_tail);
1669                 p = lp->rx_base + (new / LDC_PACKET_SIZE);
1670
1671                 ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1672                        "rcv_nxt[%08x]\n",
1673                        p->type,
1674                        p->stype,
1675                        p->ctrl,
1676                        p->env,
1677                        p->seqid,
1678                        p->u.r.ackid,
1679                        lp->rcv_nxt);
1680
1681                 if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1682                         err = rx_bad_seq(lp, p, first_frag);
1683                         copied = 0;
1684                         break;
1685                 }
1686
1687                 if (p->type & LDC_CTRL) {
1688                         err = process_control_frame(lp, p);
1689                         if (err < 0)
1690                                 break;
1691                         err = 0;
1692                 }
1693
1694                 lp->rcv_nxt = p->seqid;
1695
1696                 if (!(p->type & LDC_DATA)) {
1697                         new = rx_advance(lp, new);
1698                         goto no_data;
1699                 }
1700                 if (p->stype & (LDC_ACK | LDC_NACK)) {
1701                         err = data_ack_nack(lp, p);
1702                         if (err)
1703                                 break;
1704                 }
1705                 if (!(p->stype & LDC_INFO)) {
1706                         new = rx_advance(lp, new);
1707                         err = rx_set_head(lp, new);
1708                         if (err)
1709                                 break;
1710                         goto no_data;
1711                 }
1712
1713                 pkt_len = p->env & LDC_LEN;
1714
1715                 /* Every initial packet starts with the START bit set.
1716                  *
1717                  * Singleton packets will have both START+STOP set.
1718                  *
1719                  * Fragments will have START set in the first frame, STOP
1720                  * set in the last frame, and neither bit set in middle
1721                  * frames of the packet.
1722                  *
1723                  * Therefore if we are at the beginning of a packet and
1724                  * we don't see START, or we are in the middle of a fragmented
1725                  * packet and do see START, we are unsynchronized and should
1726                  * flush the RX queue.
1727                  */
1728                 if ((first_frag == NULL && !(p->env & LDC_START)) ||
1729                     (first_frag != NULL &&  (p->env & LDC_START))) {
1730                         if (!first_frag)
1731                                 new = rx_advance(lp, new);
1732
1733                         err = rx_set_head(lp, new);
1734                         if (err)
1735                                 break;
1736
1737                         if (!first_frag)
1738                                 goto no_data;
1739                 }
1740                 if (!first_frag)
1741                         first_frag = p;
1742
1743                 if (pkt_len > size - copied) {
1744                         /* User didn't give us a big enough buffer,
1745                          * what to do?  This is a pretty serious error.
1746                          *
1747                          * Since we haven't updated the RX ring head to
1748                          * consume any of the packets, signal the error
1749                          * to the user and just leave the RX ring alone.
1750                          *
1751                          * This seems the best behavior because this allows
1752                          * a user of the LDC layer to start with a small
1753                          * RX buffer for ldc_read() calls and use -EMSGSIZE
1754                          * as a cue to enlarge it's read buffer.
1755                          */
1756                         err = -EMSGSIZE;
1757                         break;
1758                 }
1759
1760                 /* Ok, we are gonna eat this one.  */
1761                 new = rx_advance(lp, new);
1762
1763                 memcpy(buf,
1764                        (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1765                         p->u.u_data : p->u.r.r_data), pkt_len);
1766                 buf += pkt_len;
1767                 copied += pkt_len;
1768
1769                 if (p->env & LDC_STOP)
1770                         break;
1771
1772 no_data:
1773                 if (new == lp->rx_tail) {
1774                         err = rx_data_wait(lp, new);
1775                         if (err)
1776                                 break;
1777                 }
1778         }
1779
1780         if (!err)
1781                 err = rx_set_head(lp, new);
1782
1783         if (err && first_frag)
1784                 lp->rcv_nxt = first_frag->seqid - 1;
1785
1786         if (!err) {
1787                 err = copied;
1788                 if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1789                         send_data_ack(lp);
1790         }
1791
1792         return err;
1793 }
1794
1795 static const struct ldc_mode_ops nonraw_ops = {
1796         .write          =       write_nonraw,
1797         .read           =       read_nonraw,
1798 };
1799
1800 static int write_stream(struct ldc_channel *lp, const void *buf,
1801                         unsigned int size)
1802 {
1803         if (size > lp->cfg.mtu)
1804                 size = lp->cfg.mtu;
1805         return write_nonraw(lp, buf, size);
1806 }
1807
1808 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1809 {
1810         if (!lp->mssbuf_len) {
1811                 int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1812                 if (err < 0)
1813                         return err;
1814
1815                 lp->mssbuf_len = err;
1816                 lp->mssbuf_off = 0;
1817         }
1818
1819         if (size > lp->mssbuf_len)
1820                 size = lp->mssbuf_len;
1821         memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1822
1823         lp->mssbuf_off += size;
1824         lp->mssbuf_len -= size;
1825
1826         return size;
1827 }
1828
1829 static const struct ldc_mode_ops stream_ops = {
1830         .write          =       write_stream,
1831         .read           =       read_stream,
1832 };
1833
1834 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1835 {
1836         unsigned long flags;
1837         int err;
1838
1839         if (!buf)
1840                 return -EINVAL;
1841
1842         if (!size)
1843                 return 0;
1844
1845         spin_lock_irqsave(&lp->lock, flags);
1846
1847         if (lp->hs_state != LDC_HS_COMPLETE)
1848                 err = -ENOTCONN;
1849         else
1850                 err = lp->mops->write(lp, buf, size);
1851
1852         spin_unlock_irqrestore(&lp->lock, flags);
1853
1854         return err;
1855 }
1856 EXPORT_SYMBOL(ldc_write);
1857
1858 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1859 {
1860         unsigned long flags;
1861         int err;
1862
1863         if (!buf)
1864                 return -EINVAL;
1865
1866         if (!size)
1867                 return 0;
1868
1869         spin_lock_irqsave(&lp->lock, flags);
1870
1871         if (lp->hs_state != LDC_HS_COMPLETE)
1872                 err = -ENOTCONN;
1873         else
1874                 err = lp->mops->read(lp, buf, size);
1875
1876         spin_unlock_irqrestore(&lp->lock, flags);
1877
1878         return err;
1879 }
1880 EXPORT_SYMBOL(ldc_read);
1881
1882 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1883 {
1884         struct iommu_arena *arena = &iommu->arena;
1885         unsigned long n, start, end, limit;
1886         int pass;
1887
1888         limit = arena->limit;
1889         start = arena->hint;
1890         pass = 0;
1891
1892 again:
1893         n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
1894         end = n + npages;
1895         if (unlikely(end >= limit)) {
1896                 if (likely(pass < 1)) {
1897                         limit = start;
1898                         start = 0;
1899                         pass++;
1900                         goto again;
1901                 } else {
1902                         /* Scanned the whole thing, give up. */
1903                         return -1;
1904                 }
1905         }
1906         bitmap_set(arena->map, n, npages);
1907
1908         arena->hint = end;
1909
1910         return n;
1911 }
1912
1913 #define COOKIE_PGSZ_CODE        0xf000000000000000ULL
1914 #define COOKIE_PGSZ_CODE_SHIFT  60ULL
1915
1916 static u64 pagesize_code(void)
1917 {
1918         switch (PAGE_SIZE) {
1919         default:
1920         case (8ULL * 1024ULL):
1921                 return 0;
1922         case (64ULL * 1024ULL):
1923                 return 1;
1924         case (512ULL * 1024ULL):
1925                 return 2;
1926         case (4ULL * 1024ULL * 1024ULL):
1927                 return 3;
1928         case (32ULL * 1024ULL * 1024ULL):
1929                 return 4;
1930         case (256ULL * 1024ULL * 1024ULL):
1931                 return 5;
1932         }
1933 }
1934
1935 static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1936 {
1937         return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1938                 (index << PAGE_SHIFT) |
1939                 page_offset);
1940 }
1941
1942 static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1943 {
1944         u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1945
1946         cookie &= ~COOKIE_PGSZ_CODE;
1947
1948         *shift = szcode * 3;
1949
1950         return (cookie >> (13ULL + (szcode * 3ULL)));
1951 }
1952
1953 static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1954                                              unsigned long npages)
1955 {
1956         long entry;
1957
1958         entry = arena_alloc(iommu, npages);
1959         if (unlikely(entry < 0))
1960                 return NULL;
1961
1962         return iommu->page_table + entry;
1963 }
1964
1965 static u64 perm_to_mte(unsigned int map_perm)
1966 {
1967         u64 mte_base;
1968
1969         mte_base = pagesize_code();
1970
1971         if (map_perm & LDC_MAP_SHADOW) {
1972                 if (map_perm & LDC_MAP_R)
1973                         mte_base |= LDC_MTE_COPY_R;
1974                 if (map_perm & LDC_MAP_W)
1975                         mte_base |= LDC_MTE_COPY_W;
1976         }
1977         if (map_perm & LDC_MAP_DIRECT) {
1978                 if (map_perm & LDC_MAP_R)
1979                         mte_base |= LDC_MTE_READ;
1980                 if (map_perm & LDC_MAP_W)
1981                         mte_base |= LDC_MTE_WRITE;
1982                 if (map_perm & LDC_MAP_X)
1983                         mte_base |= LDC_MTE_EXEC;
1984         }
1985         if (map_perm & LDC_MAP_IO) {
1986                 if (map_perm & LDC_MAP_R)
1987                         mte_base |= LDC_MTE_IOMMU_R;
1988                 if (map_perm & LDC_MAP_W)
1989                         mte_base |= LDC_MTE_IOMMU_W;
1990         }
1991
1992         return mte_base;
1993 }
1994
1995 static int pages_in_region(unsigned long base, long len)
1996 {
1997         int count = 0;
1998
1999         do {
2000                 unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
2001
2002                 len -= (new - base);
2003                 base = new;
2004                 count++;
2005         } while (len > 0);
2006
2007         return count;
2008 }
2009
2010 struct cookie_state {
2011         struct ldc_mtable_entry         *page_table;
2012         struct ldc_trans_cookie         *cookies;
2013         u64                             mte_base;
2014         u64                             prev_cookie;
2015         u32                             pte_idx;
2016         u32                             nc;
2017 };
2018
2019 static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2020                          unsigned long off, unsigned long len)
2021 {
2022         do {
2023                 unsigned long tlen, new = pa + PAGE_SIZE;
2024                 u64 this_cookie;
2025
2026                 sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2027
2028                 tlen = PAGE_SIZE;
2029                 if (off)
2030                         tlen = PAGE_SIZE - off;
2031                 if (tlen > len)
2032                         tlen = len;
2033
2034                 this_cookie = make_cookie(sp->pte_idx,
2035                                           pagesize_code(), off);
2036
2037                 off = 0;
2038
2039                 if (this_cookie == sp->prev_cookie) {
2040                         sp->cookies[sp->nc - 1].cookie_size += tlen;
2041                 } else {
2042                         sp->cookies[sp->nc].cookie_addr = this_cookie;
2043                         sp->cookies[sp->nc].cookie_size = tlen;
2044                         sp->nc++;
2045                 }
2046                 sp->prev_cookie = this_cookie + tlen;
2047
2048                 sp->pte_idx++;
2049
2050                 len -= tlen;
2051                 pa = new;
2052         } while (len > 0);
2053 }
2054
2055 static int sg_count_one(struct scatterlist *sg)
2056 {
2057         unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2058         long len = sg->length;
2059
2060         if ((sg->offset | len) & (8UL - 1))
2061                 return -EFAULT;
2062
2063         return pages_in_region(base + sg->offset, len);
2064 }
2065
2066 static int sg_count_pages(struct scatterlist *sg, int num_sg)
2067 {
2068         int count;
2069         int i;
2070
2071         count = 0;
2072         for (i = 0; i < num_sg; i++) {
2073                 int err = sg_count_one(sg + i);
2074                 if (err < 0)
2075                         return err;
2076                 count += err;
2077         }
2078
2079         return count;
2080 }
2081
2082 int ldc_map_sg(struct ldc_channel *lp,
2083                struct scatterlist *sg, int num_sg,
2084                struct ldc_trans_cookie *cookies, int ncookies,
2085                unsigned int map_perm)
2086 {
2087         unsigned long i, npages, flags;
2088         struct ldc_mtable_entry *base;
2089         struct cookie_state state;
2090         struct ldc_iommu *iommu;
2091         int err;
2092
2093         if (map_perm & ~LDC_MAP_ALL)
2094                 return -EINVAL;
2095
2096         err = sg_count_pages(sg, num_sg);
2097         if (err < 0)
2098                 return err;
2099
2100         npages = err;
2101         if (err > ncookies)
2102                 return -EMSGSIZE;
2103
2104         iommu = &lp->iommu;
2105
2106         spin_lock_irqsave(&iommu->lock, flags);
2107         base = alloc_npages(iommu, npages);
2108         spin_unlock_irqrestore(&iommu->lock, flags);
2109
2110         if (!base)
2111                 return -ENOMEM;
2112
2113         state.page_table = iommu->page_table;
2114         state.cookies = cookies;
2115         state.mte_base = perm_to_mte(map_perm);
2116         state.prev_cookie = ~(u64)0;
2117         state.pte_idx = (base - iommu->page_table);
2118         state.nc = 0;
2119
2120         for (i = 0; i < num_sg; i++)
2121                 fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2122                              sg[i].offset, sg[i].length);
2123
2124         return state.nc;
2125 }
2126 EXPORT_SYMBOL(ldc_map_sg);
2127
2128 int ldc_map_single(struct ldc_channel *lp,
2129                    void *buf, unsigned int len,
2130                    struct ldc_trans_cookie *cookies, int ncookies,
2131                    unsigned int map_perm)
2132 {
2133         unsigned long npages, pa, flags;
2134         struct ldc_mtable_entry *base;
2135         struct cookie_state state;
2136         struct ldc_iommu *iommu;
2137
2138         if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2139                 return -EINVAL;
2140
2141         pa = __pa(buf);
2142         if ((pa | len) & (8UL - 1))
2143                 return -EFAULT;
2144
2145         npages = pages_in_region(pa, len);
2146
2147         iommu = &lp->iommu;
2148
2149         spin_lock_irqsave(&iommu->lock, flags);
2150         base = alloc_npages(iommu, npages);
2151         spin_unlock_irqrestore(&iommu->lock, flags);
2152
2153         if (!base)
2154                 return -ENOMEM;
2155
2156         state.page_table = iommu->page_table;
2157         state.cookies = cookies;
2158         state.mte_base = perm_to_mte(map_perm);
2159         state.prev_cookie = ~(u64)0;
2160         state.pte_idx = (base - iommu->page_table);
2161         state.nc = 0;
2162         fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2163         BUG_ON(state.nc != 1);
2164
2165         return state.nc;
2166 }
2167 EXPORT_SYMBOL(ldc_map_single);
2168
2169 static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2170                         u64 cookie, u64 size)
2171 {
2172         struct iommu_arena *arena = &iommu->arena;
2173         unsigned long i, shift, index, npages;
2174         struct ldc_mtable_entry *base;
2175
2176         npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2177         index = cookie_to_index(cookie, &shift);
2178         base = iommu->page_table + index;
2179
2180         BUG_ON(index > arena->limit ||
2181                (index + npages) > arena->limit);
2182
2183         for (i = 0; i < npages; i++) {
2184                 if (base->cookie)
2185                         sun4v_ldc_revoke(id, cookie + (i << shift),
2186                                          base->cookie);
2187                 base->mte = 0;
2188                 __clear_bit(index + i, arena->map);
2189         }
2190 }
2191
2192 void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2193                int ncookies)
2194 {
2195         struct ldc_iommu *iommu = &lp->iommu;
2196         unsigned long flags;
2197         int i;
2198
2199         spin_lock_irqsave(&iommu->lock, flags);
2200         for (i = 0; i < ncookies; i++) {
2201                 u64 addr = cookies[i].cookie_addr;
2202                 u64 size = cookies[i].cookie_size;
2203
2204                 free_npages(lp->id, iommu, addr, size);
2205         }
2206         spin_unlock_irqrestore(&iommu->lock, flags);
2207 }
2208 EXPORT_SYMBOL(ldc_unmap);
2209
2210 int ldc_copy(struct ldc_channel *lp, int copy_dir,
2211              void *buf, unsigned int len, unsigned long offset,
2212              struct ldc_trans_cookie *cookies, int ncookies)
2213 {
2214         unsigned int orig_len;
2215         unsigned long ra;
2216         int i;
2217
2218         if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2219                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2220                        lp->id, copy_dir);
2221                 return -EINVAL;
2222         }
2223
2224         ra = __pa(buf);
2225         if ((ra | len | offset) & (8UL - 1)) {
2226                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2227                        "ra[%lx] len[%x] offset[%lx]\n",
2228                        lp->id, ra, len, offset);
2229                 return -EFAULT;
2230         }
2231
2232         if (lp->hs_state != LDC_HS_COMPLETE ||
2233             (lp->flags & LDC_FLAG_RESET)) {
2234                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2235                        "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2236                 return -ECONNRESET;
2237         }
2238
2239         orig_len = len;
2240         for (i = 0; i < ncookies; i++) {
2241                 unsigned long cookie_raddr = cookies[i].cookie_addr;
2242                 unsigned long this_len = cookies[i].cookie_size;
2243                 unsigned long actual_len;
2244
2245                 if (unlikely(offset)) {
2246                         unsigned long this_off = offset;
2247
2248                         if (this_off > this_len)
2249                                 this_off = this_len;
2250
2251                         offset -= this_off;
2252                         this_len -= this_off;
2253                         if (!this_len)
2254                                 continue;
2255                         cookie_raddr += this_off;
2256                 }
2257
2258                 if (this_len > len)
2259                         this_len = len;
2260
2261                 while (1) {
2262                         unsigned long hv_err;
2263
2264                         hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2265                                                 cookie_raddr, ra,
2266                                                 this_len, &actual_len);
2267                         if (unlikely(hv_err)) {
2268                                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2269                                        "HV error %lu\n",
2270                                        lp->id, hv_err);
2271                                 if (lp->hs_state != LDC_HS_COMPLETE ||
2272                                     (lp->flags & LDC_FLAG_RESET))
2273                                         return -ECONNRESET;
2274                                 else
2275                                         return -EFAULT;
2276                         }
2277
2278                         cookie_raddr += actual_len;
2279                         ra += actual_len;
2280                         len -= actual_len;
2281                         if (actual_len == this_len)
2282                                 break;
2283
2284                         this_len -= actual_len;
2285                 }
2286
2287                 if (!len)
2288                         break;
2289         }
2290
2291         /* It is caller policy what to do about short copies.
2292          * For example, a networking driver can declare the
2293          * packet a runt and drop it.
2294          */
2295
2296         return orig_len - len;
2297 }
2298 EXPORT_SYMBOL(ldc_copy);
2299
2300 void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2301                           struct ldc_trans_cookie *cookies, int *ncookies,
2302                           unsigned int map_perm)
2303 {
2304         void *buf;
2305         int err;
2306
2307         if (len & (8UL - 1))
2308                 return ERR_PTR(-EINVAL);
2309
2310         buf = kzalloc(len, GFP_KERNEL);
2311         if (!buf)
2312                 return ERR_PTR(-ENOMEM);
2313
2314         err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2315         if (err < 0) {
2316                 kfree(buf);
2317                 return ERR_PTR(err);
2318         }
2319         *ncookies = err;
2320
2321         return buf;
2322 }
2323 EXPORT_SYMBOL(ldc_alloc_exp_dring);
2324
2325 void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2326                         struct ldc_trans_cookie *cookies, int ncookies)
2327 {
2328         ldc_unmap(lp, cookies, ncookies);
2329         kfree(buf);
2330 }
2331 EXPORT_SYMBOL(ldc_free_exp_dring);
2332
2333 static int __init ldc_init(void)
2334 {
2335         unsigned long major, minor;
2336         struct mdesc_handle *hp;
2337         const u64 *v;
2338         int err;
2339         u64 mp;
2340
2341         hp = mdesc_grab();
2342         if (!hp)
2343                 return -ENODEV;
2344
2345         mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2346         err = -ENODEV;
2347         if (mp == MDESC_NODE_NULL)
2348                 goto out;
2349
2350         v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2351         if (!v)
2352                 goto out;
2353
2354         major = 1;
2355         minor = 0;
2356         if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2357                 printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2358                 goto out;
2359         }
2360
2361         printk(KERN_INFO "%s", version);
2362
2363         if (!*v) {
2364                 printk(KERN_INFO PFX "Domaining disabled.\n");
2365                 goto out;
2366         }
2367         ldom_domaining_enabled = 1;
2368         err = 0;
2369
2370 out:
2371         mdesc_release(hp);
2372         return err;
2373 }
2374
2375 core_initcall(ldc_init);