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/module.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
  18 #include <asm/hypervisor.h>
  19 #include <asm/iommu.h>
  20 #include <asm/page.h>
  21 #include <asm/ldc.h>
  22 #include <asm/mdesc.h>
  23
  24 #define DRV_MODULE_NAME         "ldc"
  25 #define PFX DRV_MODULE_NAME     ": "
  26 #define DRV_MODULE_VERSION      "1.1"
  27 #define DRV_MODULE_RELDATE      "July 22, 2008"
  28
  29 static char version[] __devinitdata =
  30         DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
  31 #define LDC_PACKET_SIZE         64
  32
  33 /* Packet header layout for unreliable and reliable mode frames.
  34  * When in RAW mode, packets are simply straight 64-byte payloads
  35  * with no headers.
  36  */
  37 struct ldc_packet {
  38         u8                      type;
  39 #define LDC_CTRL                0x01
  40 #define LDC_DATA                0x02
  41 #define LDC_ERR                 0x10
  42
  43         u8                      stype;
  44 #define LDC_INFO                0x01
  45 #define LDC_ACK                 0x02
  46 #define LDC_NACK                0x04
  47
  48         u8                      ctrl;
  49 #define LDC_VERS                0x01 /* Link Version            */
  50 #define LDC_RTS                 0x02 /* Request To Send         */
  51 #define LDC_RTR                 0x03 /* Ready To Receive        */
  52 #define LDC_RDX                 0x04 /* Ready for Data eXchange */
  53 #define LDC_CTRL_MSK            0x0f
  54
  55         u8                      env;
  56 #define LDC_LEN                 0x3f
  57 #define LDC_FRAG_MASK           0xc0
  58 #define LDC_START               0x40
  59 #define LDC_STOP                0x80
  60
  61         u32                     seqid;
  62
  63         union {
  64                 u8              u_data[LDC_PACKET_SIZE - 8];
  65                 struct {
  66                         u32     pad;
  67                         u32     ackid;
  68                         u8      r_data[LDC_PACKET_SIZE - 8 - 8];
  69                 } r;
  70         } u;
  71 };
  72
  73 struct ldc_version {
  74         u16 major;
  75         u16 minor;
  76 };
  77
  78 /* Ordered from largest major to lowest.  */
  79 static struct ldc_version ver_arr[] = {
  80         { .major = 1, .minor = 0 },
  81 };
  82
  83 #define LDC_DEFAULT_MTU                 (4 * LDC_PACKET_SIZE)
  84 #define LDC_DEFAULT_NUM_ENTRIES         (PAGE_SIZE / LDC_PACKET_SIZE)
  85
  86 struct ldc_channel;
  87
  88 struct ldc_mode_ops {
  89         int (*write)(struct ldc_channel *, const void *, unsigned int);
  90         int (*read)(struct ldc_channel *, void *, unsigned int);
  91 };
  92
  93 static const struct ldc_mode_ops raw_ops;
  94 static const struct ldc_mode_ops nonraw_ops;
  95 static const struct ldc_mode_ops stream_ops;
  96
  97 int ldom_domaining_enabled;
  98
  99 struct ldc_iommu {
 100         /* Protects arena alloc/free.  */
 101         spinlock_t                      lock;
 102         struct iommu_arena              arena;
 103         struct ldc_mtable_entry         *page_table;
 104 };
 105
 106 struct ldc_channel {
 107         /* Protects all operations that depend upon channel state.  */
 108         spinlock_t                      lock;
 109
 110         unsigned long                   id;
 111
 112         u8                              *mssbuf;
 113         u32                             mssbuf_len;
 114         u32                             mssbuf_off;
 115
 116         struct ldc_packet               *tx_base;
 117         unsigned long                   tx_head;
 118         unsigned long                   tx_tail;
 119         unsigned long                   tx_num_entries;
 120         unsigned long                   tx_ra;
 121
 122         unsigned long                   tx_acked;
 123
 124         struct ldc_packet               *rx_base;
 125         unsigned long                   rx_head;
 126         unsigned long                   rx_tail;
 127         unsigned long                   rx_num_entries;
 128         unsigned long                   rx_ra;
 129
 130         u32                             rcv_nxt;
 131         u32                             snd_nxt;
 132
 133         unsigned long                   chan_state;
 134
 135         struct ldc_channel_config       cfg;
 136         void                            *event_arg;
 137
 138         const struct ldc_mode_ops       *mops;
 139
 140         struct ldc_iommu                iommu;
 141
 142         struct ldc_version              ver;
 143
 144         u8                              hs_state;
 145 #define LDC_HS_CLOSED                   0x00
 146 #define LDC_HS_OPEN                     0x01
 147 #define LDC_HS_GOTVERS                  0x02
 148 #define LDC_HS_SENTRTR                  0x03
 149 #define LDC_HS_GOTRTR                   0x04
 150 #define LDC_HS_COMPLETE                 0x10
 151
 152         u8                              flags;
 153 #define LDC_FLAG_ALLOCED_QUEUES         0x01
 154 #define LDC_FLAG_REGISTERED_QUEUES      0x02
 155 #define LDC_FLAG_REGISTERED_IRQS        0x04
 156 #define LDC_FLAG_RESET                  0x10
 157
 158         u8                              mss;
 159         u8                              state;
 160
 161 #define LDC_IRQ_NAME_MAX                32
 162         char                            rx_irq_name[LDC_IRQ_NAME_MAX];
 163         char                            tx_irq_name[LDC_IRQ_NAME_MAX];
 164
 165         struct hlist_head               mh_list;
 166
 167         struct hlist_node               list;
 168 };
 169
 170 #define ldcdbg(TYPE, f, a...) \
 171 do {    if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
 172                 printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
 173 } while (0)
 174
 175 static const char *state_to_str(u8 state)
 176 {
 177         switch (state) {
 178         case LDC_STATE_INVALID:
 179                 return "INVALID";
 180         case LDC_STATE_INIT:
 181                 return "INIT";
 182         case LDC_STATE_BOUND:
 183                 return "BOUND";
 184         case LDC_STATE_READY:
 185                 return "READY";
 186         case LDC_STATE_CONNECTED:
 187                 return "CONNECTED";
 188         default:
 189                 return "<UNKNOWN>";
 190         }
 191 }
 192
 193 static void ldc_set_state(struct ldc_channel *lp, u8 state)
 194 {
 195         ldcdbg(STATE, "STATE (%s) --> (%s)\n",
 196                state_to_str(lp->state),
 197                state_to_str(state));
 198
 199         lp->state = state;
 200 }
 201
 202 static unsigned long __advance(unsigned long off, unsigned long num_entries)
 203 {
 204         off += LDC_PACKET_SIZE;
 205         if (off == (num_entries * LDC_PACKET_SIZE))
 206                 off = 0;
 207
 208         return off;
 209 }
 210
 211 static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
 212 {
 213         return __advance(off, lp->rx_num_entries);
 214 }
 215
 216 static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
 217 {
 218         return __advance(off, lp->tx_num_entries);
 219 }
 220
 221 static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp,
 222                                                   unsigned long *new_tail)
 223 {
 224         struct ldc_packet *p;
 225         unsigned long t;
 226
 227         t = tx_advance(lp, lp->tx_tail);
 228         if (t == lp->tx_head)
 229                 return NULL;
 230
 231         *new_tail = t;
 232
 233         p = lp->tx_base;
 234         return p + (lp->tx_tail / LDC_PACKET_SIZE);
 235 }
 236
 237 /* When we are in reliable or stream mode, have to track the next packet
 238  * we haven't gotten an ACK for in the TX queue using tx_acked.  We have
 239  * to be careful not to stomp over the queue past that point.  During
 240  * the handshake, we don't have TX data packets pending in the queue
 241  * and that's why handshake_get_tx_packet() need not be mindful of
 242  * lp->tx_acked.
 243  */
 244 static unsigned long head_for_data(struct ldc_channel *lp)
 245 {
 246         if (lp->cfg.mode == LDC_MODE_STREAM)
 247                 return lp->tx_acked;
 248         return lp->tx_head;
 249 }
 250
 251 static int tx_has_space_for(struct ldc_channel *lp, unsigned int size)
 252 {
 253         unsigned long limit, tail, new_tail, diff;
 254         unsigned int mss;
 255
 256         limit = head_for_data(lp);
 257         tail = lp->tx_tail;
 258         new_tail = tx_advance(lp, tail);
 259         if (new_tail == limit)
 260                 return 0;
 261
 262         if (limit > new_tail)
 263                 diff = limit - new_tail;
 264         else
 265                 diff = (limit +
 266                         ((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail));
 267         diff /= LDC_PACKET_SIZE;
 268         mss = lp->mss;
 269
 270         if (diff * mss < size)
 271                 return 0;
 272
 273         return 1;
 274 }
 275
 276 static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp,
 277                                              unsigned long *new_tail)
 278 {
 279         struct ldc_packet *p;
 280         unsigned long h, t;
 281
 282         h = head_for_data(lp);
 283         t = tx_advance(lp, lp->tx_tail);
 284         if (t == h)
 285                 return NULL;
 286
 287         *new_tail = t;
 288
 289         p = lp->tx_base;
 290         return p + (lp->tx_tail / LDC_PACKET_SIZE);
 291 }
 292
 293 static int set_tx_tail(struct ldc_channel *lp, unsigned long tail)
 294 {
 295         unsigned long orig_tail = lp->tx_tail;
 296         int limit = 1000;
 297
 298         lp->tx_tail = tail;
 299         while (limit-- > 0) {
 300                 unsigned long err;
 301
 302                 err = sun4v_ldc_tx_set_qtail(lp->id, tail);
 303                 if (!err)
 304                         return 0;
 305
 306                 if (err != HV_EWOULDBLOCK) {
 307                         lp->tx_tail = orig_tail;
 308                         return -EINVAL;
 309                 }
 310                 udelay(1);
 311         }
 312
 313         lp->tx_tail = orig_tail;
 314         return -EBUSY;
 315 }
 316
 317 /* This just updates the head value in the hypervisor using
 318  * a polling loop with a timeout.  The caller takes care of
 319  * upating software state representing the head change, if any.
 320  */
 321 static int __set_rx_head(struct ldc_channel *lp, unsigned long head)
 322 {
 323         int limit = 1000;
 324
 325         while (limit-- > 0) {
 326                 unsigned long err;
 327
 328                 err = sun4v_ldc_rx_set_qhead(lp->id, head);
 329                 if (!err)
 330                         return 0;
 331
 332                 if (err != HV_EWOULDBLOCK)
 333                         return -EINVAL;
 334
 335                 udelay(1);
 336         }
 337
 338         return -EBUSY;
 339 }
 340
 341 static int send_tx_packet(struct ldc_channel *lp,
 342                           struct ldc_packet *p,
 343                           unsigned long new_tail)
 344 {
 345         BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE)));
 346
 347         return set_tx_tail(lp, new_tail);
 348 }
 349
 350 static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp,
 351                                                  u8 stype, u8 ctrl,
 352                                                  void *data, int dlen,
 353                                                  unsigned long *new_tail)
 354 {
 355         struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail);
 356
 357         if (p) {
 358                 memset(p, 0, sizeof(*p));
 359                 p->type = LDC_CTRL;
 360                 p->stype = stype;
 361                 p->ctrl = ctrl;
 362                 if (data)
 363                         memcpy(p->u.u_data, data, dlen);
 364         }
 365         return p;
 366 }
 367
 368 static int start_handshake(struct ldc_channel *lp)
 369 {
 370         struct ldc_packet *p;
 371         struct ldc_version *ver;
 372         unsigned long new_tail;
 373
 374         ver = &ver_arr[0];
 375
 376         ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n",
 377                ver->major, ver->minor);
 378
 379         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
 380                                    ver, sizeof(*ver), &new_tail);
 381         if (p) {
 382                 int err = send_tx_packet(lp, p, new_tail);
 383                 if (!err)
 384                         lp->flags &= ~LDC_FLAG_RESET;
 385                 return err;
 386         }
 387         return -EBUSY;
 388 }
 389
 390 static int send_version_nack(struct ldc_channel *lp,
 391                              u16 major, u16 minor)
 392 {
 393         struct ldc_packet *p;
 394         struct ldc_version ver;
 395         unsigned long new_tail;
 396
 397         ver.major = major;
 398         ver.minor = minor;
 399
 400         p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS,
 401                                    &ver, sizeof(ver), &new_tail);
 402         if (p) {
 403                 ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n",
 404                        ver.major, ver.minor);
 405
 406                 return send_tx_packet(lp, p, new_tail);
 407         }
 408         return -EBUSY;
 409 }
 410
 411 static int send_version_ack(struct ldc_channel *lp,
 412                             struct ldc_version *vp)
 413 {
 414         struct ldc_packet *p;
 415         unsigned long new_tail;
 416
 417         p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS,
 418                                    vp, sizeof(*vp), &new_tail);
 419         if (p) {
 420                 ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n",
 421                        vp->major, vp->minor);
 422
 423                 return send_tx_packet(lp, p, new_tail);
 424         }
 425         return -EBUSY;
 426 }
 427
 428 static int send_rts(struct ldc_channel *lp)
 429 {
 430         struct ldc_packet *p;
 431         unsigned long new_tail;
 432
 433         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0,
 434                                    &new_tail);
 435         if (p) {
 436                 p->env = lp->cfg.mode;
 437                 p->seqid = 0;
 438                 lp->rcv_nxt = 0;
 439
 440                 ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n",
 441                        p->env, p->seqid);
 442
 443                 return send_tx_packet(lp, p, new_tail);
 444         }
 445         return -EBUSY;
 446 }
 447
 448 static int send_rtr(struct ldc_channel *lp)
 449 {
 450         struct ldc_packet *p;
 451         unsigned long new_tail;
 452
 453         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0,
 454                                    &new_tail);
 455         if (p) {
 456                 p->env = lp->cfg.mode;
 457                 p->seqid = 0;
 458
 459                 ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n",
 460                        p->env, p->seqid);
 461
 462                 return send_tx_packet(lp, p, new_tail);
 463         }
 464         return -EBUSY;
 465 }
 466
 467 static int send_rdx(struct ldc_channel *lp)
 468 {
 469         struct ldc_packet *p;
 470         unsigned long new_tail;
 471
 472         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0,
 473                                    &new_tail);
 474         if (p) {
 475                 p->env = 0;
 476                 p->seqid = ++lp->snd_nxt;
 477                 p->u.r.ackid = lp->rcv_nxt;
 478
 479                 ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n",
 480                        p->env, p->seqid, p->u.r.ackid);
 481
 482                 return send_tx_packet(lp, p, new_tail);
 483         }
 484         return -EBUSY;
 485 }
 486
 487 static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt)
 488 {
 489         struct ldc_packet *p;
 490         unsigned long new_tail;
 491         int err;
 492
 493         p = data_get_tx_packet(lp, &new_tail);
 494         if (!p)
 495                 return -EBUSY;
 496         memset(p, 0, sizeof(*p));
 497         p->type = data_pkt->type;
 498         p->stype = LDC_NACK;
 499         p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK;
 500         p->seqid = lp->snd_nxt + 1;
 501         p->u.r.ackid = lp->rcv_nxt;
 502
 503         ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n",
 504                p->type, p->ctrl, p->seqid, p->u.r.ackid);
 505
 506         err = send_tx_packet(lp, p, new_tail);
 507         if (!err)
 508                 lp->snd_nxt++;
 509
 510         return err;
 511 }
 512
 513 static int ldc_abort(struct ldc_channel *lp)
 514 {
 515         unsigned long hv_err;
 516
 517         ldcdbg(STATE, "ABORT\n");
 518
 519         /* We report but do not act upon the hypervisor errors because
 520          * there really isn't much we can do if they fail at this point.
 521          */
 522         hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
 523         if (hv_err)
 524                 printk(KERN_ERR PFX "ldc_abort: "
 525                        "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
 526                        lp->id, lp->tx_ra, lp->tx_num_entries, hv_err);
 527
 528         hv_err = sun4v_ldc_tx_get_state(lp->id,
 529                                         &lp->tx_head,
 530                                         &lp->tx_tail,
 531                                         &lp->chan_state);
 532         if (hv_err)
 533                 printk(KERN_ERR PFX "ldc_abort: "
 534                        "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n",
 535                        lp->id, hv_err);
 536
 537         hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
 538         if (hv_err)
 539                 printk(KERN_ERR PFX "ldc_abort: "
 540                        "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
 541                        lp->id, lp->rx_ra, lp->rx_num_entries, hv_err);
 542
 543         /* Refetch the RX queue state as well, because we could be invoked
 544          * here in the queue processing context.
 545          */
 546         hv_err = sun4v_ldc_rx_get_state(lp->id,
 547                                         &lp->rx_head,
 548                                         &lp->rx_tail,
 549                                         &lp->chan_state);
 550         if (hv_err)
 551                 printk(KERN_ERR PFX "ldc_abort: "
 552                        "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n",
 553                        lp->id, hv_err);
 554
 555         return -ECONNRESET;
 556 }
 557
 558 static struct ldc_version *find_by_major(u16 major)
 559 {
 560         struct ldc_version *ret = NULL;
 561         int i;
 562
 563         for (i = 0; i < ARRAY_SIZE(ver_arr); i++) {
 564                 struct ldc_version *v = &ver_arr[i];
 565                 if (v->major <= major) {
 566                         ret = v;
 567                         break;
 568                 }
 569         }
 570         return ret;
 571 }
 572
 573 static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp)
 574 {
 575         struct ldc_version *vap;
 576         int err;
 577
 578         ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n",
 579                vp->major, vp->minor);
 580
 581         if (lp->hs_state == LDC_HS_GOTVERS) {
 582                 lp->hs_state = LDC_HS_OPEN;
 583                 memset(&lp->ver, 0, sizeof(lp->ver));
 584         }
 585
 586         vap = find_by_major(vp->major);
 587         if (!vap) {
 588                 err = send_version_nack(lp, 0, 0);
 589         } else if (vap->major != vp->major) {
 590                 err = send_version_nack(lp, vap->major, vap->minor);
 591         } else {
 592                 struct ldc_version ver = *vp;
 593                 if (ver.minor > vap->minor)
 594                         ver.minor = vap->minor;
 595                 err = send_version_ack(lp, &ver);
 596                 if (!err) {
 597                         lp->ver = ver;
 598                         lp->hs_state = LDC_HS_GOTVERS;
 599                 }
 600         }
 601         if (err)
 602                 return ldc_abort(lp);
 603
 604         return 0;
 605 }
 606
 607 static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp)
 608 {
 609         ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n",
 610                vp->major, vp->minor);
 611
 612         if (lp->hs_state == LDC_HS_GOTVERS) {
 613                 if (lp->ver.major != vp->major ||
 614                     lp->ver.minor != vp->minor)
 615                         return ldc_abort(lp);
 616         } else {
 617                 lp->ver = *vp;
 618                 lp->hs_state = LDC_HS_GOTVERS;
 619         }
 620         if (send_rts(lp))
 621                 return ldc_abort(lp);
 622         return 0;
 623 }
 624
 625 static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp)
 626 {
 627         struct ldc_version *vap;
 628         struct ldc_packet *p;
 629         unsigned long new_tail;
 630
 631         if (vp->major == 0 && vp->minor == 0)
 632                 return ldc_abort(lp);
 633
 634         vap = find_by_major(vp->major);
 635         if (!vap)
 636                 return ldc_abort(lp);
 637
 638         p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
 639                                            vap, sizeof(*vap),
 640                                            &new_tail);
 641         if (!p)
 642                 return ldc_abort(lp);
 643
 644         return send_tx_packet(lp, p, new_tail);
 645 }
 646
 647 static int process_version(struct ldc_channel *lp,
 648                            struct ldc_packet *p)
 649 {
 650         struct ldc_version *vp;
 651
 652         vp = (struct ldc_version *) p->u.u_data;
 653
 654         switch (p->stype) {
 655         case LDC_INFO:
 656                 return process_ver_info(lp, vp);
 657
 658         case LDC_ACK:
 659                 return process_ver_ack(lp, vp);
 660
 661         case LDC_NACK:
 662                 return process_ver_nack(lp, vp);
 663
 664         default:
 665                 return ldc_abort(lp);
 666         }
 667 }
 668
 669 static int process_rts(struct ldc_channel *lp,
 670                        struct ldc_packet *p)
 671 {
 672         ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n",
 673                p->stype, p->seqid, p->env);
 674
 675         if (p->stype     != LDC_INFO       ||
 676             lp->hs_state != LDC_HS_GOTVERS ||
 677             p->env       != lp->cfg.mode)
 678                 return ldc_abort(lp);
 679
 680         lp->snd_nxt = p->seqid;
 681         lp->rcv_nxt = p->seqid;
 682         lp->hs_state = LDC_HS_SENTRTR;
 683         if (send_rtr(lp))
 684                 return ldc_abort(lp);
 685
 686         return 0;
 687 }
 688
 689 static int process_rtr(struct ldc_channel *lp,
 690                        struct ldc_packet *p)
 691 {
 692         ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n",
 693                p->stype, p->seqid, p->env);
 694
 695         if (p->stype     != LDC_INFO ||
 696             p->env       != lp->cfg.mode)
 697                 return ldc_abort(lp);
 698
 699         lp->snd_nxt = p->seqid;
 700         lp->hs_state = LDC_HS_COMPLETE;
 701         ldc_set_state(lp, LDC_STATE_CONNECTED);
 702         send_rdx(lp);
 703
 704         return LDC_EVENT_UP;
 705 }
 706
 707 static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
 708 {
 709         return lp->rcv_nxt + 1 == seqid;
 710 }
 711
 712 static int process_rdx(struct ldc_channel *lp,
 713                        struct ldc_packet *p)
 714 {
 715         ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n",
 716                p->stype, p->seqid, p->env, p->u.r.ackid);
 717
 718         if (p->stype != LDC_INFO ||
 719             !(rx_seq_ok(lp, p->seqid)))
 720                 return ldc_abort(lp);
 721
 722         lp->rcv_nxt = p->seqid;
 723
 724         lp->hs_state = LDC_HS_COMPLETE;
 725         ldc_set_state(lp, LDC_STATE_CONNECTED);
 726
 727         return LDC_EVENT_UP;
 728 }
 729
 730 static int process_control_frame(struct ldc_channel *lp,
 731                                  struct ldc_packet *p)
 732 {
 733         switch (p->ctrl) {
 734         case LDC_VERS:
 735                 return process_version(lp, p);
 736
 737         case LDC_RTS:
 738                 return process_rts(lp, p);
 739
 740         case LDC_RTR:
 741                 return process_rtr(lp, p);
 742
 743         case LDC_RDX:
 744                 return process_rdx(lp, p);
 745
 746         default:
 747                 return ldc_abort(lp);
 748         }
 749 }
 750
 751 static int process_error_frame(struct ldc_channel *lp,
 752                                struct ldc_packet *p)
 753 {
 754         return ldc_abort(lp);
 755 }
 756
 757 static int process_data_ack(struct ldc_channel *lp,
 758                             struct ldc_packet *ack)
 759 {
 760         unsigned long head = lp->tx_acked;
 761         u32 ackid = ack->u.r.ackid;
 762
 763         while (1) {
 764                 struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE);
 765
 766                 head = tx_advance(lp, head);
 767
 768                 if (p->seqid == ackid) {
 769                         lp->tx_acked = head;
 770                         return 0;
 771                 }
 772                 if (head == lp->tx_tail)
 773                         return ldc_abort(lp);
 774         }
 775
 776         return 0;
 777 }
 778
 779 static void send_events(struct ldc_channel *lp, unsigned int event_mask)
 780 {
 781         if (event_mask & LDC_EVENT_RESET)
 782                 lp->cfg.event(lp->event_arg, LDC_EVENT_RESET);
 783         if (event_mask & LDC_EVENT_UP)
 784                 lp->cfg.event(lp->event_arg, LDC_EVENT_UP);
 785         if (event_mask & LDC_EVENT_DATA_READY)
 786                 lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
 787 }
 788
 789 static irqreturn_t ldc_rx(int irq, void *dev_id)
 790 {
 791         struct ldc_channel *lp = dev_id;
 792         unsigned long orig_state, hv_err, flags;
 793         unsigned int event_mask;
 794
 795         spin_lock_irqsave(&lp->lock, flags);
 796
 797         orig_state = lp->chan_state;
 798         hv_err = sun4v_ldc_rx_get_state(lp->id,
 799                                         &lp->rx_head,
 800                                         &lp->rx_tail,
 801                                         &lp->chan_state);
 802
 803         ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
 804                orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
 805
 806         event_mask = 0;
 807
 808         if (lp->cfg.mode == LDC_MODE_RAW &&
 809             lp->chan_state == LDC_CHANNEL_UP) {
 810                 lp->hs_state = LDC_HS_COMPLETE;
 811                 ldc_set_state(lp, LDC_STATE_CONNECTED);
 812
 813                 event_mask |= LDC_EVENT_UP;
 814
 815                 orig_state = lp->chan_state;
 816         }
 817
 818         /* If we are in reset state, flush the RX queue and ignore
 819          * everything.
 820          */
 821         if (lp->flags & LDC_FLAG_RESET) {
 822                 (void) __set_rx_head(lp, lp->rx_tail);
 823                 goto out;
 824         }
 825
 826         /* Once we finish the handshake, we let the ldc_read()
 827          * paths do all of the control frame and state management.
 828          * Just trigger the callback.
 829          */
 830         if (lp->hs_state == LDC_HS_COMPLETE) {
 831 handshake_complete:
 832                 if (lp->chan_state != orig_state) {
 833                         unsigned int event = LDC_EVENT_RESET;
 834
 835                         if (lp->chan_state == LDC_CHANNEL_UP)
 836                                 event = LDC_EVENT_UP;
 837
 838                         event_mask |= event;
 839                 }
 840                 if (lp->rx_head != lp->rx_tail)
 841                         event_mask |= LDC_EVENT_DATA_READY;
 842
 843                 goto out;
 844         }
 845
 846         if (lp->chan_state != orig_state)
 847                 goto out;
 848
 849         while (lp->rx_head != lp->rx_tail) {
 850                 struct ldc_packet *p;
 851                 unsigned long new;
 852                 int err;
 853
 854                 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
 855
 856                 switch (p->type) {
 857                 case LDC_CTRL:
 858                         err = process_control_frame(lp, p);
 859                         if (err > 0)
 860                                 event_mask |= err;
 861                         break;
 862
 863                 case LDC_DATA:
 864                         event_mask |= LDC_EVENT_DATA_READY;
 865                         err = 0;
 866                         break;
 867
 868                 case LDC_ERR:
 869                         err = process_error_frame(lp, p);
 870                         break;
 871
 872                 default:
 873                         err = ldc_abort(lp);
 874                         break;
 875                 }
 876
 877                 if (err < 0)
 878                         break;
 879
 880                 new = lp->rx_head;
 881                 new += LDC_PACKET_SIZE;
 882                 if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
 883                         new = 0;
 884                 lp->rx_head = new;
 885
 886                 err = __set_rx_head(lp, new);
 887                 if (err < 0) {
 888                         (void) ldc_abort(lp);
 889                         break;
 890                 }
 891                 if (lp->hs_state == LDC_HS_COMPLETE)
 892                         goto handshake_complete;
 893         }
 894
 895 out:
 896         spin_unlock_irqrestore(&lp->lock, flags);
 897
 898         send_events(lp, event_mask);
 899
 900         return IRQ_HANDLED;
 901 }
 902
 903 static irqreturn_t ldc_tx(int irq, void *dev_id)
 904 {
 905         struct ldc_channel *lp = dev_id;
 906         unsigned long flags, hv_err, orig_state;
 907         unsigned int event_mask = 0;
 908
 909         spin_lock_irqsave(&lp->lock, flags);
 910
 911         orig_state = lp->chan_state;
 912         hv_err = sun4v_ldc_tx_get_state(lp->id,
 913                                         &lp->tx_head,
 914                                         &lp->tx_tail,
 915                                         &lp->chan_state);
 916
 917         ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
 918                orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
 919
 920         if (lp->cfg.mode == LDC_MODE_RAW &&
 921             lp->chan_state == LDC_CHANNEL_UP) {
 922                 lp->hs_state = LDC_HS_COMPLETE;
 923                 ldc_set_state(lp, LDC_STATE_CONNECTED);
 924
 925                 event_mask |= LDC_EVENT_UP;
 926         }
 927
 928         spin_unlock_irqrestore(&lp->lock, flags);
 929
 930         send_events(lp, event_mask);
 931
 932         return IRQ_HANDLED;
 933 }
 934
 935 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
 936  * XXX that addition and removal from the ldc_channel_list has
 937  * XXX atomicity, otherwise the __ldc_channel_exists() check is
 938  * XXX totally pointless as another thread can slip into ldc_alloc()
 939  * XXX and add a channel with the same ID.  There also needs to be
 940  * XXX a spinlock for ldc_channel_list.
 941  */
 942 static HLIST_HEAD(ldc_channel_list);
 943
 944 static int __ldc_channel_exists(unsigned long id)
 945 {
 946         struct ldc_channel *lp;
 947         struct hlist_node *n;
 948
 949         hlist_for_each_entry(lp, n, &ldc_channel_list, list) {
 950                 if (lp->id == id)
 951                         return 1;
 952         }
 953         return 0;
 954 }
 955
 956 static int alloc_queue(const char *name, unsigned long num_entries,
 957                        struct ldc_packet **base, unsigned long *ra)
 958 {
 959         unsigned long size, order;
 960         void *q;
 961
 962         size = num_entries * LDC_PACKET_SIZE;
 963         order = get_order(size);
 964
 965         q = (void *) __get_free_pages(GFP_KERNEL, order);
 966         if (!q) {
 967                 printk(KERN_ERR PFX "Alloc of %s queue failed with "
 968                        "size=%lu order=%lu\n", name, size, order);
 969                 return -ENOMEM;
 970         }
 971
 972         memset(q, 0, PAGE_SIZE << order);
 973
 974         *base = q;
 975         *ra = __pa(q);
 976
 977         return 0;
 978 }
 979
 980 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
 981 {
 982         unsigned long size, order;
 983
 984         if (!q)
 985                 return;
 986
 987         size = num_entries * LDC_PACKET_SIZE;
 988         order = get_order(size);
 989
 990         free_pages((unsigned long)q, order);
 991 }
 992
 993 /* XXX Make this configurable... XXX */
 994 #define LDC_IOTABLE_SIZE        (8 * 1024)
 995
 996 static int ldc_iommu_init(struct ldc_channel *lp)
 997 {
 998         unsigned long sz, num_tsb_entries, tsbsize, order;
 999         struct ldc_iommu *iommu = &lp->iommu;
1000         struct ldc_mtable_entry *table;
1001         unsigned long hv_err;
1002         int err;
1003
1004         num_tsb_entries = LDC_IOTABLE_SIZE;
1005         tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1006
1007         spin_lock_init(&iommu->lock);
1008
1009         sz = num_tsb_entries / 8;
1010         sz = (sz + 7UL) & ~7UL;
1011         iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1012         if (!iommu->arena.map) {
1013                 printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1014                 return -ENOMEM;
1015         }
1016
1017         iommu->arena.limit = num_tsb_entries;
1018
1019         order = get_order(tsbsize);
1020
1021         table = (struct ldc_mtable_entry *)
1022                 __get_free_pages(GFP_KERNEL, order);
1023         err = -ENOMEM;
1024         if (!table) {
1025                 printk(KERN_ERR PFX "Alloc of MTE table failed, "
1026                        "size=%lu order=%lu\n", tsbsize, order);
1027                 goto out_free_map;
1028         }
1029
1030         memset(table, 0, PAGE_SIZE << order);
1031
1032         iommu->page_table = table;
1033
1034         hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1035                                          num_tsb_entries);
1036         err = -EINVAL;
1037         if (hv_err)
1038                 goto out_free_table;
1039
1040         return 0;
1041
1042 out_free_table:
1043         free_pages((unsigned long) table, order);
1044         iommu->page_table = NULL;
1045
1046 out_free_map:
1047         kfree(iommu->arena.map);
1048         iommu->arena.map = NULL;
1049
1050         return err;
1051 }
1052
1053 static void ldc_iommu_release(struct ldc_channel *lp)
1054 {
1055         struct ldc_iommu *iommu = &lp->iommu;
1056         unsigned long num_tsb_entries, tsbsize, order;
1057
1058         (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1059
1060         num_tsb_entries = iommu->arena.limit;
1061         tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1062         order = get_order(tsbsize);
1063
1064         free_pages((unsigned long) iommu->page_table, order);
1065         iommu->page_table = NULL;
1066
1067         kfree(iommu->arena.map);
1068         iommu->arena.map = NULL;
1069 }
1070
1071 struct ldc_channel *ldc_alloc(unsigned long id,
1072                               const struct ldc_channel_config *cfgp,
1073                               void *event_arg)
1074 {
1075         struct ldc_channel *lp;
1076         const struct ldc_mode_ops *mops;
1077         unsigned long dummy1, dummy2, hv_err;
1078         u8 mss, *mssbuf;
1079         int err;
1080
1081         err = -ENODEV;
1082         if (!ldom_domaining_enabled)
1083                 goto out_err;
1084
1085         err = -EINVAL;
1086         if (!cfgp)
1087                 goto out_err;
1088
1089         switch (cfgp->mode) {
1090         case LDC_MODE_RAW:
1091                 mops = &raw_ops;
1092                 mss = LDC_PACKET_SIZE;
1093                 break;
1094
1095         case LDC_MODE_UNRELIABLE:
1096                 mops = &nonraw_ops;
1097                 mss = LDC_PACKET_SIZE - 8;
1098                 break;
1099
1100         case LDC_MODE_STREAM:
1101                 mops = &stream_ops;
1102                 mss = LDC_PACKET_SIZE - 8 - 8;
1103                 break;
1104
1105         default:
1106                 goto out_err;
1107         }
1108
1109         if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1110                 goto out_err;
1111
1112         hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1113         err = -ENODEV;
1114         if (hv_err == HV_ECHANNEL)
1115                 goto out_err;
1116
1117         err = -EEXIST;
1118         if (__ldc_channel_exists(id))
1119                 goto out_err;
1120
1121         mssbuf = NULL;
1122
1123         lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1124         err = -ENOMEM;
1125         if (!lp)
1126                 goto out_err;
1127
1128         spin_lock_init(&lp->lock);
1129
1130         lp->id = id;
1131
1132         err = ldc_iommu_init(lp);
1133         if (err)
1134                 goto out_free_ldc;
1135
1136         lp->mops = mops;
1137         lp->mss = mss;
1138
1139         lp->cfg = *cfgp;
1140         if (!lp->cfg.mtu)
1141                 lp->cfg.mtu = LDC_DEFAULT_MTU;
1142
1143         if (lp->cfg.mode == LDC_MODE_STREAM) {
1144                 mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1145                 if (!mssbuf) {
1146                         err = -ENOMEM;
1147                         goto out_free_iommu;
1148                 }
1149                 lp->mssbuf = mssbuf;
1150         }
1151
1152         lp->event_arg = event_arg;
1153
1154         /* XXX allow setting via ldc_channel_config to override defaults
1155          * XXX or use some formula based upon mtu
1156          */
1157         lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1158         lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1159
1160         err = alloc_queue("TX", lp->tx_num_entries,
1161                           &lp->tx_base, &lp->tx_ra);
1162         if (err)
1163                 goto out_free_mssbuf;
1164
1165         err = alloc_queue("RX", lp->rx_num_entries,
1166                           &lp->rx_base, &lp->rx_ra);
1167         if (err)
1168                 goto out_free_txq;
1169
1170         lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1171
1172         lp->hs_state = LDC_HS_CLOSED;
1173         ldc_set_state(lp, LDC_STATE_INIT);
1174
1175         INIT_HLIST_NODE(&lp->list);
1176         hlist_add_head(&lp->list, &ldc_channel_list);
1177
1178         INIT_HLIST_HEAD(&lp->mh_list);
1179
1180         return lp;
1181
1182 out_free_txq:
1183         free_queue(lp->tx_num_entries, lp->tx_base);
1184
1185 out_free_mssbuf:
1186         kfree(mssbuf);
1187
1188 out_free_iommu:
1189         ldc_iommu_release(lp);
1190
1191 out_free_ldc:
1192         kfree(lp);
1193
1194 out_err:
1195         return ERR_PTR(err);
1196 }
1197 EXPORT_SYMBOL(ldc_alloc);
1198
1199 void ldc_free(struct ldc_channel *lp)
1200 {
1201         if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1202                 free_irq(lp->cfg.rx_irq, lp);
1203                 free_irq(lp->cfg.tx_irq, lp);
1204         }
1205
1206         if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1207                 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1208                 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1209                 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1210         }
1211         if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1212                 free_queue(lp->tx_num_entries, lp->tx_base);
1213                 free_queue(lp->rx_num_entries, lp->rx_base);
1214                 lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1215         }
1216
1217         hlist_del(&lp->list);
1218
1219         kfree(lp->mssbuf);
1220
1221         ldc_iommu_release(lp);
1222
1223         kfree(lp);
1224 }
1225 EXPORT_SYMBOL(ldc_free);
1226
1227 /* Bind the channel.  This registers the LDC queues with
1228  * the hypervisor and puts the channel into a pseudo-listening
1229  * state.  This does not initiate a handshake, ldc_connect() does
1230  * that.
1231  */
1232 int ldc_bind(struct ldc_channel *lp, const char *name)
1233 {
1234         unsigned long hv_err, flags;
1235         int err = -EINVAL;
1236
1237         if (!name ||
1238             (lp->state != LDC_STATE_INIT))
1239                 return -EINVAL;
1240
1241         snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1242         snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1243
1244         err = request_irq(lp->cfg.rx_irq, ldc_rx,
1245                           IRQF_SAMPLE_RANDOM | IRQF_SHARED,
1246                           lp->rx_irq_name, lp);
1247         if (err)
1248                 return err;
1249
1250         err = request_irq(lp->cfg.tx_irq, ldc_tx,
1251                           IRQF_SAMPLE_RANDOM | IRQF_SHARED,
1252                           lp->tx_irq_name, lp);
1253         if (err) {
1254                 free_irq(lp->cfg.rx_irq, lp);
1255                 return err;
1256         }
1257
1258
1259         spin_lock_irqsave(&lp->lock, flags);
1260
1261         enable_irq(lp->cfg.rx_irq);
1262         enable_irq(lp->cfg.tx_irq);
1263
1264         lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1265
1266         err = -ENODEV;
1267         hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1268         if (hv_err)
1269                 goto out_free_irqs;
1270
1271         hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1272         if (hv_err)
1273                 goto out_free_irqs;
1274
1275         hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1276         if (hv_err)
1277                 goto out_unmap_tx;
1278
1279         hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1280         if (hv_err)
1281                 goto out_unmap_tx;
1282
1283         lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1284
1285         hv_err = sun4v_ldc_tx_get_state(lp->id,
1286                                         &lp->tx_head,
1287                                         &lp->tx_tail,
1288                                         &lp->chan_state);
1289         err = -EBUSY;
1290         if (hv_err)
1291                 goto out_unmap_rx;
1292
1293         lp->tx_acked = lp->tx_head;
1294
1295         lp->hs_state = LDC_HS_OPEN;
1296         ldc_set_state(lp, LDC_STATE_BOUND);
1297
1298         spin_unlock_irqrestore(&lp->lock, flags);
1299
1300         return 0;
1301
1302 out_unmap_rx:
1303         lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1304         sun4v_ldc_rx_qconf(lp->id, 0, 0);
1305
1306 out_unmap_tx:
1307         sun4v_ldc_tx_qconf(lp->id, 0, 0);
1308
1309 out_free_irqs:
1310         lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1311         free_irq(lp->cfg.tx_irq, lp);
1312         free_irq(lp->cfg.rx_irq, lp);
1313
1314         spin_unlock_irqrestore(&lp->lock, flags);
1315
1316         return err;
1317 }
1318 EXPORT_SYMBOL(ldc_bind);
1319
1320 int ldc_connect(struct ldc_channel *lp)
1321 {
1322         unsigned long flags;
1323         int err;
1324
1325         if (lp->cfg.mode == LDC_MODE_RAW)
1326                 return -EINVAL;
1327
1328         spin_lock_irqsave(&lp->lock, flags);
1329
1330         if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1331             !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1332             lp->hs_state != LDC_HS_OPEN)
1333                 err = -EINVAL;
1334         else
1335                 err = start_handshake(lp);
1336
1337         spin_unlock_irqrestore(&lp->lock, flags);
1338
1339         return err;
1340 }
1341 EXPORT_SYMBOL(ldc_connect);
1342
1343 int ldc_disconnect(struct ldc_channel *lp)
1344 {
1345         unsigned long hv_err, flags;
1346         int err;
1347
1348         if (lp->cfg.mode == LDC_MODE_RAW)
1349                 return -EINVAL;
1350
1351         if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1352             !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1353                 return -EINVAL;
1354
1355         spin_lock_irqsave(&lp->lock, flags);
1356
1357         err = -ENODEV;
1358         hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1359         if (hv_err)
1360                 goto out_err;
1361
1362         hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1363         if (hv_err)
1364                 goto out_err;
1365
1366         hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1367         if (hv_err)
1368                 goto out_err;
1369
1370         hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1371         if (hv_err)
1372                 goto out_err;
1373
1374         ldc_set_state(lp, LDC_STATE_BOUND);
1375         lp->hs_state = LDC_HS_OPEN;
1376         lp->flags |= LDC_FLAG_RESET;
1377
1378         spin_unlock_irqrestore(&lp->lock, flags);
1379
1380         return 0;
1381
1382 out_err:
1383         sun4v_ldc_tx_qconf(lp->id, 0, 0);
1384         sun4v_ldc_rx_qconf(lp->id, 0, 0);
1385         free_irq(lp->cfg.tx_irq, lp);
1386         free_irq(lp->cfg.rx_irq, lp);
1387         lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1388                        LDC_FLAG_REGISTERED_QUEUES);
1389         ldc_set_state(lp, LDC_STATE_INIT);
1390
1391         spin_unlock_irqrestore(&lp->lock, flags);
1392
1393         return err;
1394 }
1395 EXPORT_SYMBOL(ldc_disconnect);
1396
1397 int ldc_state(struct ldc_channel *lp)
1398 {
1399         return lp->state;
1400 }
1401 EXPORT_SYMBOL(ldc_state);
1402
1403 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1404 {
1405         struct ldc_packet *p;
1406         unsigned long new_tail;
1407         int err;
1408
1409         if (size > LDC_PACKET_SIZE)
1410                 return -EMSGSIZE;
1411
1412         p = data_get_tx_packet(lp, &new_tail);
1413         if (!p)
1414                 return -EAGAIN;
1415
1416         memcpy(p, buf, size);
1417
1418         err = send_tx_packet(lp, p, new_tail);
1419         if (!err)
1420                 err = size;
1421
1422         return err;
1423 }
1424
1425 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1426 {
1427         struct ldc_packet *p;
1428         unsigned long hv_err, new;
1429         int err;
1430
1431         if (size < LDC_PACKET_SIZE)
1432                 return -EINVAL;
1433
1434         hv_err = sun4v_ldc_rx_get_state(lp->id,
1435                                         &lp->rx_head,
1436                                         &lp->rx_tail,
1437                                         &lp->chan_state);
1438         if (hv_err)
1439                 return ldc_abort(lp);
1440
1441         if (lp->chan_state == LDC_CHANNEL_DOWN ||
1442             lp->chan_state == LDC_CHANNEL_RESETTING)
1443                 return -ECONNRESET;
1444
1445         if (lp->rx_head == lp->rx_tail)
1446                 return 0;
1447
1448         p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1449         memcpy(buf, p, LDC_PACKET_SIZE);
1450
1451         new = rx_advance(lp, lp->rx_head);
1452         lp->rx_head = new;
1453
1454         err = __set_rx_head(lp, new);
1455         if (err < 0)
1456                 err = -ECONNRESET;
1457         else
1458                 err = LDC_PACKET_SIZE;
1459
1460         return err;
1461 }
1462
1463 static const struct ldc_mode_ops raw_ops = {
1464         .write          =       write_raw,
1465         .read           =       read_raw,
1466 };
1467
1468 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1469                         unsigned int size)
1470 {
1471         unsigned long hv_err, tail;
1472         unsigned int copied;
1473         u32 seq;
1474         int err;
1475
1476         hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1477                                         &lp->chan_state);
1478         if (unlikely(hv_err))
1479                 return -EBUSY;
1480
1481         if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1482                 return ldc_abort(lp);
1483
1484         if (!tx_has_space_for(lp, size))
1485                 return -EAGAIN;
1486
1487         seq = lp->snd_nxt;
1488         copied = 0;
1489         tail = lp->tx_tail;
1490         while (copied < size) {
1491                 struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1492                 u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1493                             p->u.u_data :
1494                             p->u.r.r_data);
1495                 int data_len;
1496
1497                 p->type = LDC_DATA;
1498                 p->stype = LDC_INFO;
1499                 p->ctrl = 0;
1500
1501                 data_len = size - copied;
1502                 if (data_len > lp->mss)
1503                         data_len = lp->mss;
1504
1505                 BUG_ON(data_len > LDC_LEN);
1506
1507                 p->env = (data_len |
1508                           (copied == 0 ? LDC_START : 0) |
1509                           (data_len == size - copied ? LDC_STOP : 0));
1510
1511                 p->seqid = ++seq;
1512
1513                 ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1514                        p->type,
1515                        p->stype,
1516                        p->ctrl,
1517                        p->env,
1518                        p->seqid);
1519
1520                 memcpy(data, buf, data_len);
1521                 buf += data_len;
1522                 copied += data_len;
1523
1524                 tail = tx_advance(lp, tail);
1525         }
1526
1527         err = set_tx_tail(lp, tail);
1528         if (!err) {
1529                 lp->snd_nxt = seq;
1530                 err = size;
1531         }
1532
1533         return err;
1534 }
1535
1536 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1537                       struct ldc_packet *first_frag)
1538 {
1539         int err;
1540
1541         if (first_frag)
1542                 lp->rcv_nxt = first_frag->seqid - 1;
1543
1544         err = send_data_nack(lp, p);
1545         if (err)
1546                 return err;
1547
1548         err = __set_rx_head(lp, lp->rx_tail);
1549         if (err < 0)
1550                 return ldc_abort(lp);
1551
1552         return 0;
1553 }
1554
1555 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1556 {
1557         if (p->stype & LDC_ACK) {
1558                 int err = process_data_ack(lp, p);
1559                 if (err)
1560                         return err;
1561         }
1562         if (p->stype & LDC_NACK)
1563                 return ldc_abort(lp);
1564
1565         return 0;
1566 }
1567
1568 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1569 {
1570         unsigned long dummy;
1571         int limit = 1000;
1572
1573         ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1574                cur_head, lp->rx_head, lp->rx_tail);
1575         while (limit-- > 0) {
1576                 unsigned long hv_err;
1577
1578                 hv_err = sun4v_ldc_rx_get_state(lp->id,
1579                                                 &dummy,
1580                                                 &lp->rx_tail,
1581                                                 &lp->chan_state);
1582                 if (hv_err)
1583                         return ldc_abort(lp);
1584
1585                 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1586                     lp->chan_state == LDC_CHANNEL_RESETTING)
1587                         return -ECONNRESET;
1588
1589                 if (cur_head != lp->rx_tail) {
1590                         ldcdbg(DATA, "DATA WAIT DONE "
1591                                "head[%lx] tail[%lx] chan_state[%lx]\n",
1592                                dummy, lp->rx_tail, lp->chan_state);
1593                         return 0;
1594                 }
1595
1596                 udelay(1);
1597         }
1598         return -EAGAIN;
1599 }
1600
1601 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1602 {
1603         int err = __set_rx_head(lp, head);
1604
1605         if (err < 0)
1606                 return ldc_abort(lp);
1607
1608         lp->rx_head = head;
1609         return 0;
1610 }
1611
1612 static void send_data_ack(struct ldc_channel *lp)
1613 {
1614         unsigned long new_tail;
1615         struct ldc_packet *p;
1616
1617         p = data_get_tx_packet(lp, &new_tail);
1618         if (likely(p)) {
1619                 int err;
1620
1621                 memset(p, 0, sizeof(*p));
1622                 p->type = LDC_DATA;
1623                 p->stype = LDC_ACK;
1624                 p->ctrl = 0;
1625                 p->seqid = lp->snd_nxt + 1;
1626                 p->u.r.ackid = lp->rcv_nxt;
1627
1628                 err = send_tx_packet(lp, p, new_tail);
1629                 if (!err)
1630                         lp->snd_nxt++;
1631         }
1632 }
1633
1634 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1635 {
1636         struct ldc_packet *first_frag;
1637         unsigned long hv_err, new;
1638         int err, copied;
1639
1640         hv_err = sun4v_ldc_rx_get_state(lp->id,
1641                                         &lp->rx_head,
1642                                         &lp->rx_tail,
1643                                         &lp->chan_state);
1644         if (hv_err)
1645                 return ldc_abort(lp);
1646
1647         if (lp->chan_state == LDC_CHANNEL_DOWN ||
1648             lp->chan_state == LDC_CHANNEL_RESETTING)
1649                 return -ECONNRESET;
1650
1651         if (lp->rx_head == lp->rx_tail)
1652                 return 0;
1653
1654         first_frag = NULL;
1655         copied = err = 0;
1656         new = lp->rx_head;
1657         while (1) {
1658                 struct ldc_packet *p;
1659                 int pkt_len;
1660
1661                 BUG_ON(new == lp->rx_tail);
1662                 p = lp->rx_base + (new / LDC_PACKET_SIZE);
1663
1664                 ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1665                        "rcv_nxt[%08x]\n",
1666                        p->type,
1667                        p->stype,
1668                        p->ctrl,
1669                        p->env,
1670                        p->seqid,
1671                        p->u.r.ackid,
1672                        lp->rcv_nxt);
1673
1674                 if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1675                         err = rx_bad_seq(lp, p, first_frag);
1676                         copied = 0;
1677                         break;
1678                 }
1679
1680                 if (p->type & LDC_CTRL) {
1681                         err = process_control_frame(lp, p);
1682                         if (err < 0)
1683                                 break;
1684                         err = 0;
1685                 }
1686
1687                 lp->rcv_nxt = p->seqid;
1688
1689                 if (!(p->type & LDC_DATA)) {
1690                         new = rx_advance(lp, new);
1691                         goto no_data;
1692                 }
1693                 if (p->stype & (LDC_ACK | LDC_NACK)) {
1694                         err = data_ack_nack(lp, p);
1695                         if (err)
1696                                 break;
1697                 }
1698                 if (!(p->stype & LDC_INFO)) {
1699                         new = rx_advance(lp, new);
1700                         err = rx_set_head(lp, new);
1701                         if (err)
1702                                 break;
1703                         goto no_data;
1704                 }
1705
1706                 pkt_len = p->env & LDC_LEN;
1707
1708                 /* Every initial packet starts with the START bit set.
1709                  *
1710                  * Singleton packets will have both START+STOP set.
1711                  *
1712                  * Fragments will have START set in the first frame, STOP
1713                  * set in the last frame, and neither bit set in middle
1714                  * frames of the packet.
1715                  *
1716                  * Therefore if we are at the beginning of a packet and
1717                  * we don't see START, or we are in the middle of a fragmented
1718                  * packet and do see START, we are unsynchronized and should
1719                  * flush the RX queue.
1720                  */
1721                 if ((first_frag == NULL && !(p->env & LDC_START)) ||
1722                     (first_frag != NULL &&  (p->env & LDC_START))) {
1723                         if (!first_frag)
1724                                 new = rx_advance(lp, new);
1725
1726                         err = rx_set_head(lp, new);
1727                         if (err)
1728                                 break;
1729
1730                         if (!first_frag)
1731                                 goto no_data;
1732                 }
1733                 if (!first_frag)
1734                         first_frag = p;
1735
1736                 if (pkt_len > size - copied) {
1737                         /* User didn't give us a big enough buffer,
1738                          * what to do?  This is a pretty serious error.
1739                          *
1740                          * Since we haven't updated the RX ring head to
1741                          * consume any of the packets, signal the error
1742                          * to the user and just leave the RX ring alone.
1743                          *
1744                          * This seems the best behavior because this allows
1745                          * a user of the LDC layer to start with a small
1746                          * RX buffer for ldc_read() calls and use -EMSGSIZE
1747                          * as a cue to enlarge it's read buffer.
1748                          */
1749                         err = -EMSGSIZE;
1750                         break;
1751                 }
1752
1753                 /* Ok, we are gonna eat this one.  */
1754                 new = rx_advance(lp, new);
1755
1756                 memcpy(buf,
1757                        (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1758                         p->u.u_data : p->u.r.r_data), pkt_len);
1759                 buf += pkt_len;
1760                 copied += pkt_len;
1761
1762                 if (p->env & LDC_STOP)
1763                         break;
1764
1765 no_data:
1766                 if (new == lp->rx_tail) {
1767                         err = rx_data_wait(lp, new);
1768                         if (err)
1769                                 break;
1770                 }
1771         }
1772
1773         if (!err)
1774                 err = rx_set_head(lp, new);
1775
1776         if (err && first_frag)
1777                 lp->rcv_nxt = first_frag->seqid - 1;
1778
1779         if (!err) {
1780                 err = copied;
1781                 if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1782                         send_data_ack(lp);
1783         }
1784
1785         return err;
1786 }
1787
1788 static const struct ldc_mode_ops nonraw_ops = {
1789         .write          =       write_nonraw,
1790         .read           =       read_nonraw,
1791 };
1792
1793 static int write_stream(struct ldc_channel *lp, const void *buf,
1794                         unsigned int size)
1795 {
1796         if (size > lp->cfg.mtu)
1797                 size = lp->cfg.mtu;
1798         return write_nonraw(lp, buf, size);
1799 }
1800
1801 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1802 {
1803         if (!lp->mssbuf_len) {
1804                 int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1805                 if (err < 0)
1806                         return err;
1807
1808                 lp->mssbuf_len = err;
1809                 lp->mssbuf_off = 0;
1810         }
1811
1812         if (size > lp->mssbuf_len)
1813                 size = lp->mssbuf_len;
1814         memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1815
1816         lp->mssbuf_off += size;
1817         lp->mssbuf_len -= size;
1818
1819         return size;
1820 }
1821
1822 static const struct ldc_mode_ops stream_ops = {
1823         .write          =       write_stream,
1824         .read           =       read_stream,
1825 };
1826
1827 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1828 {
1829         unsigned long flags;
1830         int err;
1831
1832         if (!buf)
1833                 return -EINVAL;
1834
1835         if (!size)
1836                 return 0;
1837
1838         spin_lock_irqsave(&lp->lock, flags);
1839
1840         if (lp->hs_state != LDC_HS_COMPLETE)
1841                 err = -ENOTCONN;
1842         else
1843                 err = lp->mops->write(lp, buf, size);
1844
1845         spin_unlock_irqrestore(&lp->lock, flags);
1846
1847         return err;
1848 }
1849 EXPORT_SYMBOL(ldc_write);
1850
1851 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1852 {
1853         unsigned long flags;
1854         int err;
1855
1856         if (!buf)
1857                 return -EINVAL;
1858
1859         if (!size)
1860                 return 0;
1861
1862         spin_lock_irqsave(&lp->lock, flags);
1863
1864         if (lp->hs_state != LDC_HS_COMPLETE)
1865                 err = -ENOTCONN;
1866         else
1867                 err = lp->mops->read(lp, buf, size);
1868
1869         spin_unlock_irqrestore(&lp->lock, flags);
1870
1871         return err;
1872 }
1873 EXPORT_SYMBOL(ldc_read);
1874
1875 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1876 {
1877         struct iommu_arena *arena = &iommu->arena;
1878         unsigned long n, i, start, end, limit;
1879         int pass;
1880
1881         limit = arena->limit;
1882         start = arena->hint;
1883         pass = 0;
1884
1885 again:
1886         n = find_next_zero_bit(arena->map, limit, start);
1887         end = n + npages;
1888         if (unlikely(end >= limit)) {
1889                 if (likely(pass < 1)) {
1890                         limit = start;
1891                         start = 0;
1892                         pass++;
1893                         goto again;
1894                 } else {
1895                         /* Scanned the whole thing, give up. */
1896                         return -1;
1897                 }
1898         }
1899
1900         for (i = n; i < end; i++) {
1901                 if (test_bit(i, arena->map)) {
1902                         start = i + 1;
1903                         goto again;
1904                 }
1905         }
1906
1907         for (i = n; i < end; i++)
1908                 __set_bit(i, arena->map);
1909
1910         arena->hint = end;
1911
1912         return n;
1913 }
1914
1915 #define COOKIE_PGSZ_CODE        0xf000000000000000ULL
1916 #define COOKIE_PGSZ_CODE_SHIFT  60ULL
1917
1918 static u64 pagesize_code(void)
1919 {
1920         switch (PAGE_SIZE) {
1921         default:
1922         case (8ULL * 1024ULL):
1923                 return 0;
1924         case (64ULL * 1024ULL):
1925                 return 1;
1926         case (512ULL * 1024ULL):
1927                 return 2;
1928         case (4ULL * 1024ULL * 1024ULL):
1929                 return 3;
1930         case (32ULL * 1024ULL * 1024ULL):
1931                 return 4;
1932         case (256ULL * 1024ULL * 1024ULL):
1933                 return 5;
1934         }
1935 }
1936
1937 static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1938 {
1939         return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1940                 (index << PAGE_SHIFT) |
1941                 page_offset);
1942 }
1943
1944 static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1945 {
1946         u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1947
1948         cookie &= ~COOKIE_PGSZ_CODE;
1949
1950         *shift = szcode * 3;
1951
1952         return (cookie >> (13ULL + (szcode * 3ULL)));
1953 }
1954
1955 static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1956                                              unsigned long npages)
1957 {
1958         long entry;
1959
1960         entry = arena_alloc(iommu, npages);
1961         if (unlikely(entry < 0))
1962                 return NULL;
1963
1964         return iommu->page_table + entry;
1965 }
1966
1967 static u64 perm_to_mte(unsigned int map_perm)
1968 {
1969         u64 mte_base;
1970
1971         mte_base = pagesize_code();
1972
1973         if (map_perm & LDC_MAP_SHADOW) {
1974                 if (map_perm & LDC_MAP_R)
1975                         mte_base |= LDC_MTE_COPY_R;
1976                 if (map_perm & LDC_MAP_W)
1977                         mte_base |= LDC_MTE_COPY_W;
1978         }
1979         if (map_perm & LDC_MAP_DIRECT) {
1980                 if (map_perm & LDC_MAP_R)
1981                         mte_base |= LDC_MTE_READ;
1982                 if (map_perm & LDC_MAP_W)
1983                         mte_base |= LDC_MTE_WRITE;
1984                 if (map_perm & LDC_MAP_X)
1985                         mte_base |= LDC_MTE_EXEC;
1986         }
1987         if (map_perm & LDC_MAP_IO) {
1988                 if (map_perm & LDC_MAP_R)
1989                         mte_base |= LDC_MTE_IOMMU_R;
1990                 if (map_perm & LDC_MAP_W)
1991                         mte_base |= LDC_MTE_IOMMU_W;
1992         }
1993
1994         return mte_base;
1995 }
1996
1997 static int pages_in_region(unsigned long base, long len)
1998 {
1999         int count = 0;
2000
2001         do {
2002                 unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
2003
2004                 len -= (new - base);
2005                 base = new;
2006                 count++;
2007         } while (len > 0);
2008
2009         return count;
2010 }
2011
2012 struct cookie_state {
2013         struct ldc_mtable_entry         *page_table;
2014         struct ldc_trans_cookie         *cookies;
2015         u64                             mte_base;
2016         u64                             prev_cookie;
2017         u32                             pte_idx;
2018         u32                             nc;
2019 };
2020
2021 static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2022                          unsigned long off, unsigned long len)
2023 {
2024         do {
2025                 unsigned long tlen, new = pa + PAGE_SIZE;
2026                 u64 this_cookie;
2027
2028                 sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2029
2030                 tlen = PAGE_SIZE;
2031                 if (off)
2032                         tlen = PAGE_SIZE - off;
2033                 if (tlen > len)
2034                         tlen = len;
2035
2036                 this_cookie = make_cookie(sp->pte_idx,
2037                                           pagesize_code(), off);
2038
2039                 off = 0;
2040
2041                 if (this_cookie == sp->prev_cookie) {
2042                         sp->cookies[sp->nc - 1].cookie_size += tlen;
2043                 } else {
2044                         sp->cookies[sp->nc].cookie_addr = this_cookie;
2045                         sp->cookies[sp->nc].cookie_size = tlen;
2046                         sp->nc++;
2047                 }
2048                 sp->prev_cookie = this_cookie + tlen;
2049
2050                 sp->pte_idx++;
2051
2052                 len -= tlen;
2053                 pa = new;
2054         } while (len > 0);
2055 }
2056
2057 static int sg_count_one(struct scatterlist *sg)
2058 {
2059         unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2060         long len = sg->length;
2061
2062         if ((sg->offset | len) & (8UL - 1))
2063                 return -EFAULT;
2064
2065         return pages_in_region(base + sg->offset, len);
2066 }
2067
2068 static int sg_count_pages(struct scatterlist *sg, int num_sg)
2069 {
2070         int count;
2071         int i;
2072
2073         count = 0;
2074         for (i = 0; i < num_sg; i++) {
2075                 int err = sg_count_one(sg + i);
2076                 if (err < 0)
2077                         return err;
2078                 count += err;
2079         }
2080
2081         return count;
2082 }
2083
2084 int ldc_map_sg(struct ldc_channel *lp,
2085                struct scatterlist *sg, int num_sg,
2086                struct ldc_trans_cookie *cookies, int ncookies,
2087                unsigned int map_perm)
2088 {
2089         unsigned long i, npages, flags;
2090         struct ldc_mtable_entry *base;
2091         struct cookie_state state;
2092         struct ldc_iommu *iommu;
2093         int err;
2094
2095         if (map_perm & ~LDC_MAP_ALL)
2096                 return -EINVAL;
2097
2098         err = sg_count_pages(sg, num_sg);
2099         if (err < 0)
2100                 return err;
2101
2102         npages = err;
2103         if (err > ncookies)
2104                 return -EMSGSIZE;
2105
2106         iommu = &lp->iommu;
2107
2108         spin_lock_irqsave(&iommu->lock, flags);
2109         base = alloc_npages(iommu, npages);
2110         spin_unlock_irqrestore(&iommu->lock, flags);
2111
2112         if (!base)
2113                 return -ENOMEM;
2114
2115         state.page_table = iommu->page_table;
2116         state.cookies = cookies;
2117         state.mte_base = perm_to_mte(map_perm);
2118         state.prev_cookie = ~(u64)0;
2119         state.pte_idx = (base - iommu->page_table);
2120         state.nc = 0;
2121
2122         for (i = 0; i < num_sg; i++)
2123                 fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2124                              sg[i].offset, sg[i].length);
2125
2126         return state.nc;
2127 }
2128 EXPORT_SYMBOL(ldc_map_sg);
2129
2130 int ldc_map_single(struct ldc_channel *lp,
2131                    void *buf, unsigned int len,
2132                    struct ldc_trans_cookie *cookies, int ncookies,
2133                    unsigned int map_perm)
2134 {
2135         unsigned long npages, pa, flags;
2136         struct ldc_mtable_entry *base;
2137         struct cookie_state state;
2138         struct ldc_iommu *iommu;
2139
2140         if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2141                 return -EINVAL;
2142
2143         pa = __pa(buf);
2144         if ((pa | len) & (8UL - 1))
2145                 return -EFAULT;
2146
2147         npages = pages_in_region(pa, len);
2148
2149         iommu = &lp->iommu;
2150
2151         spin_lock_irqsave(&iommu->lock, flags);
2152         base = alloc_npages(iommu, npages);
2153         spin_unlock_irqrestore(&iommu->lock, flags);
2154
2155         if (!base)
2156                 return -ENOMEM;
2157
2158         state.page_table = iommu->page_table;
2159         state.cookies = cookies;
2160         state.mte_base = perm_to_mte(map_perm);
2161         state.prev_cookie = ~(u64)0;
2162         state.pte_idx = (base - iommu->page_table);
2163         state.nc = 0;
2164         fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2165         BUG_ON(state.nc != 1);
2166
2167         return state.nc;
2168 }
2169 EXPORT_SYMBOL(ldc_map_single);
2170
2171 static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2172                         u64 cookie, u64 size)
2173 {
2174         struct iommu_arena *arena = &iommu->arena;
2175         unsigned long i, shift, index, npages;
2176         struct ldc_mtable_entry *base;
2177
2178         npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2179         index = cookie_to_index(cookie, &shift);
2180         base = iommu->page_table + index;
2181
2182         BUG_ON(index > arena->limit ||
2183                (index + npages) > arena->limit);
2184
2185         for (i = 0; i < npages; i++) {
2186                 if (base->cookie)
2187                         sun4v_ldc_revoke(id, cookie + (i << shift),
2188                                          base->cookie);
2189                 base->mte = 0;
2190                 __clear_bit(index + i, arena->map);
2191         }
2192 }
2193
2194 void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2195                int ncookies)
2196 {
2197         struct ldc_iommu *iommu = &lp->iommu;
2198         unsigned long flags;
2199         int i;
2200
2201         spin_lock_irqsave(&iommu->lock, flags);
2202         for (i = 0; i < ncookies; i++) {
2203                 u64 addr = cookies[i].cookie_addr;
2204                 u64 size = cookies[i].cookie_size;
2205
2206                 free_npages(lp->id, iommu, addr, size);
2207         }
2208         spin_unlock_irqrestore(&iommu->lock, flags);
2209 }
2210 EXPORT_SYMBOL(ldc_unmap);
2211
2212 int ldc_copy(struct ldc_channel *lp, int copy_dir,
2213              void *buf, unsigned int len, unsigned long offset,
2214              struct ldc_trans_cookie *cookies, int ncookies)
2215 {
2216         unsigned int orig_len;
2217         unsigned long ra;
2218         int i;
2219
2220         if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2221                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2222                        lp->id, copy_dir);
2223                 return -EINVAL;
2224         }
2225
2226         ra = __pa(buf);
2227         if ((ra | len | offset) & (8UL - 1)) {
2228                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2229                        "ra[%lx] len[%x] offset[%lx]\n",
2230                        lp->id, ra, len, offset);
2231                 return -EFAULT;
2232         }
2233
2234         if (lp->hs_state != LDC_HS_COMPLETE ||
2235             (lp->flags & LDC_FLAG_RESET)) {
2236                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2237                        "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2238                 return -ECONNRESET;
2239         }
2240
2241         orig_len = len;
2242         for (i = 0; i < ncookies; i++) {
2243                 unsigned long cookie_raddr = cookies[i].cookie_addr;
2244                 unsigned long this_len = cookies[i].cookie_size;
2245                 unsigned long actual_len;
2246
2247                 if (unlikely(offset)) {
2248                         unsigned long this_off = offset;
2249
2250                         if (this_off > this_len)
2251                                 this_off = this_len;
2252
2253                         offset -= this_off;
2254                         this_len -= this_off;
2255                         if (!this_len)
2256                                 continue;
2257                         cookie_raddr += this_off;
2258                 }
2259
2260                 if (this_len > len)
2261                         this_len = len;
2262
2263                 while (1) {
2264                         unsigned long hv_err;
2265
2266                         hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2267                                                 cookie_raddr, ra,
2268                                                 this_len, &actual_len);
2269                         if (unlikely(hv_err)) {
2270                                 printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2271                                        "HV error %lu\n",
2272                                        lp->id, hv_err);
2273                                 if (lp->hs_state != LDC_HS_COMPLETE ||
2274                                     (lp->flags & LDC_FLAG_RESET))
2275                                         return -ECONNRESET;
2276                                 else
2277                                         return -EFAULT;
2278                         }
2279
2280                         cookie_raddr += actual_len;
2281                         ra += actual_len;
2282                         len -= actual_len;
2283                         if (actual_len == this_len)
2284                                 break;
2285
2286                         this_len -= actual_len;
2287                 }
2288
2289                 if (!len)
2290                         break;
2291         }
2292
2293         /* It is caller policy what to do about short copies.
2294          * For example, a networking driver can declare the
2295          * packet a runt and drop it.
2296          */
2297
2298         return orig_len - len;
2299 }
2300 EXPORT_SYMBOL(ldc_copy);
2301
2302 void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2303                           struct ldc_trans_cookie *cookies, int *ncookies,
2304                           unsigned int map_perm)
2305 {
2306         void *buf;
2307         int err;
2308
2309         if (len & (8UL - 1))
2310                 return ERR_PTR(-EINVAL);
2311
2312         buf = kzalloc(len, GFP_KERNEL);
2313         if (!buf)
2314                 return ERR_PTR(-ENOMEM);
2315
2316         err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2317         if (err < 0) {
2318                 kfree(buf);
2319                 return ERR_PTR(err);
2320         }
2321         *ncookies = err;
2322
2323         return buf;
2324 }
2325 EXPORT_SYMBOL(ldc_alloc_exp_dring);
2326
2327 void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2328                         struct ldc_trans_cookie *cookies, int ncookies)
2329 {
2330         ldc_unmap(lp, cookies, ncookies);
2331         kfree(buf);
2332 }
2333 EXPORT_SYMBOL(ldc_free_exp_dring);
2334
2335 static int __init ldc_init(void)
2336 {
2337         unsigned long major, minor;
2338         struct mdesc_handle *hp;
2339         const u64 *v;
2340         int err;
2341         u64 mp;
2342
2343         hp = mdesc_grab();
2344         if (!hp)
2345                 return -ENODEV;
2346
2347         mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2348         err = -ENODEV;
2349         if (mp == MDESC_NODE_NULL)
2350                 goto out;
2351
2352         v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2353         if (!v)
2354                 goto out;
2355
2356         major = 1;
2357         minor = 0;
2358         if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2359                 printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2360                 goto out;
2361         }
2362
2363         printk(KERN_INFO "%s", version);
2364
2365         if (!*v) {
2366                 printk(KERN_INFO PFX "Domaining disabled.\n");
2367                 goto out;
2368         }
2369         ldom_domaining_enabled = 1;
2370         err = 0;
2371
2372 out:
2373         mdesc_release(hp);
2374         return err;
2375 }
2376
2377 core_initcall(ldc_init);