linux/arch/sparc/kernel/ldc.c
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   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
  30static char version[] =
  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 */
  38struct 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
  74struct ldc_version {
  75        u16 major;
  76        u16 minor;
  77};
  78
  79/* Ordered from largest major to lowest.  */
  80static 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
  87struct ldc_channel;
  88
  89struct ldc_mode_ops {
  90        int (*write)(struct ldc_channel *, const void *, unsigned int);
  91        int (*read)(struct ldc_channel *, void *, unsigned int);
  92};
  93
  94static const struct ldc_mode_ops raw_ops;
  95static const struct ldc_mode_ops nonraw_ops;
  96static const struct ldc_mode_ops stream_ops;
  97
  98int ldom_domaining_enabled;
  99
 100struct 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
 107struct 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...) \
 172do {    if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
 173                printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
 174} while (0)
 175
 176static 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
 194static 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
 203static 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
 212static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
 213{
 214        return __advance(off, lp->rx_num_entries);
 215}
 216
 217static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
 218{
 219        return __advance(off, lp->tx_num_entries);
 220}
 221
 222static 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 */
 245static 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
 252static 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
 277static 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
 294static 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 */
 322static 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
 342static 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
 351static 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
 369static 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
 391static 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
 412static 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
 429static 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
 449static 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
 468static 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
 488static 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
 514static 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
 559static 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
 574static 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
 608static 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
 626static 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
 648static 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
 670static 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
 690static 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
 708static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
 709{
 710        return lp->rcv_nxt + 1 == seqid;
 711}
 712
 713static 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
 731static 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
 752static int process_error_frame(struct ldc_channel *lp,
 753                               struct ldc_packet *p)
 754{
 755        return ldc_abort(lp);
 756}
 757
 758static 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
 780static 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
 790static 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) {
 836handshake_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
 900out:
 901        spin_unlock_irqrestore(&lp->lock, flags);
 902
 903        send_events(lp, event_mask);
 904
 905        return IRQ_HANDLED;
 906}
 907
 908static 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 */
 951static HLIST_HEAD(ldc_channel_list);
 952
 953static int __ldc_channel_exists(unsigned long id)
 954{
 955        struct ldc_channel *lp;
 956
 957        hlist_for_each_entry(lp, &ldc_channel_list, list) {
 958                if (lp->id == id)
 959                        return 1;
 960        }
 961        return 0;
 962}
 963
 964static int alloc_queue(const char *name, unsigned long num_entries,
 965                       struct ldc_packet **base, unsigned long *ra)
 966{
 967        unsigned long size, order;
 968        void *q;
 969
 970        size = num_entries * LDC_PACKET_SIZE;
 971        order = get_order(size);
 972
 973        q = (void *) __get_free_pages(GFP_KERNEL, order);
 974        if (!q) {
 975                printk(KERN_ERR PFX "Alloc of %s queue failed with "
 976                       "size=%lu order=%lu\n", name, size, order);
 977                return -ENOMEM;
 978        }
 979
 980        memset(q, 0, PAGE_SIZE << order);
 981
 982        *base = q;
 983        *ra = __pa(q);
 984
 985        return 0;
 986}
 987
 988static void free_queue(unsigned long num_entries, struct ldc_packet *q)
 989{
 990        unsigned long size, order;
 991
 992        if (!q)
 993                return;
 994
 995        size = num_entries * LDC_PACKET_SIZE;
 996        order = get_order(size);
 997
 998        free_pages((unsigned long)q, order);
 999}
1000
1001/* XXX Make this configurable... XXX */
1002#define LDC_IOTABLE_SIZE        (8 * 1024)
1003
1004static int ldc_iommu_init(struct ldc_channel *lp)
1005{
1006        unsigned long sz, num_tsb_entries, tsbsize, order;
1007        struct ldc_iommu *iommu = &lp->iommu;
1008        struct ldc_mtable_entry *table;
1009        unsigned long hv_err;
1010        int err;
1011
1012        num_tsb_entries = LDC_IOTABLE_SIZE;
1013        tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1014
1015        spin_lock_init(&iommu->lock);
1016
1017        sz = num_tsb_entries / 8;
1018        sz = (sz + 7UL) & ~7UL;
1019        iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1020        if (!iommu->arena.map) {
1021                printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1022                return -ENOMEM;
1023        }
1024
1025        iommu->arena.limit = num_tsb_entries;
1026
1027        order = get_order(tsbsize);
1028
1029        table = (struct ldc_mtable_entry *)
1030                __get_free_pages(GFP_KERNEL, order);
1031        err = -ENOMEM;
1032        if (!table) {
1033                printk(KERN_ERR PFX "Alloc of MTE table failed, "
1034                       "size=%lu order=%lu\n", tsbsize, order);
1035                goto out_free_map;
1036        }
1037
1038        memset(table, 0, PAGE_SIZE << order);
1039
1040        iommu->page_table = table;
1041
1042        hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1043                                         num_tsb_entries);
1044        err = -EINVAL;
1045        if (hv_err)
1046                goto out_free_table;
1047
1048        return 0;
1049
1050out_free_table:
1051        free_pages((unsigned long) table, order);
1052        iommu->page_table = NULL;
1053
1054out_free_map:
1055        kfree(iommu->arena.map);
1056        iommu->arena.map = NULL;
1057
1058        return err;
1059}
1060
1061static void ldc_iommu_release(struct ldc_channel *lp)
1062{
1063        struct ldc_iommu *iommu = &lp->iommu;
1064        unsigned long num_tsb_entries, tsbsize, order;
1065
1066        (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1067
1068        num_tsb_entries = iommu->arena.limit;
1069        tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1070        order = get_order(tsbsize);
1071
1072        free_pages((unsigned long) iommu->page_table, order);
1073        iommu->page_table = NULL;
1074
1075        kfree(iommu->arena.map);
1076        iommu->arena.map = NULL;
1077}
1078
1079struct ldc_channel *ldc_alloc(unsigned long id,
1080                              const struct ldc_channel_config *cfgp,
1081                              void *event_arg)
1082{
1083        struct ldc_channel *lp;
1084        const struct ldc_mode_ops *mops;
1085        unsigned long dummy1, dummy2, hv_err;
1086        u8 mss, *mssbuf;
1087        int err;
1088
1089        err = -ENODEV;
1090        if (!ldom_domaining_enabled)
1091                goto out_err;
1092
1093        err = -EINVAL;
1094        if (!cfgp)
1095                goto out_err;
1096
1097        switch (cfgp->mode) {
1098        case LDC_MODE_RAW:
1099                mops = &raw_ops;
1100                mss = LDC_PACKET_SIZE;
1101                break;
1102
1103        case LDC_MODE_UNRELIABLE:
1104                mops = &nonraw_ops;
1105                mss = LDC_PACKET_SIZE - 8;
1106                break;
1107
1108        case LDC_MODE_STREAM:
1109                mops = &stream_ops;
1110                mss = LDC_PACKET_SIZE - 8 - 8;
1111                break;
1112
1113        default:
1114                goto out_err;
1115        }
1116
1117        if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1118                goto out_err;
1119
1120        hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1121        err = -ENODEV;
1122        if (hv_err == HV_ECHANNEL)
1123                goto out_err;
1124
1125        err = -EEXIST;
1126        if (__ldc_channel_exists(id))
1127                goto out_err;
1128
1129        mssbuf = NULL;
1130
1131        lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1132        err = -ENOMEM;
1133        if (!lp)
1134                goto out_err;
1135
1136        spin_lock_init(&lp->lock);
1137
1138        lp->id = id;
1139
1140        err = ldc_iommu_init(lp);
1141        if (err)
1142                goto out_free_ldc;
1143
1144        lp->mops = mops;
1145        lp->mss = mss;
1146
1147        lp->cfg = *cfgp;
1148        if (!lp->cfg.mtu)
1149                lp->cfg.mtu = LDC_DEFAULT_MTU;
1150
1151        if (lp->cfg.mode == LDC_MODE_STREAM) {
1152                mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1153                if (!mssbuf) {
1154                        err = -ENOMEM;
1155                        goto out_free_iommu;
1156                }
1157                lp->mssbuf = mssbuf;
1158        }
1159
1160        lp->event_arg = event_arg;
1161
1162        /* XXX allow setting via ldc_channel_config to override defaults
1163         * XXX or use some formula based upon mtu
1164         */
1165        lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1166        lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1167
1168        err = alloc_queue("TX", lp->tx_num_entries,
1169                          &lp->tx_base, &lp->tx_ra);
1170        if (err)
1171                goto out_free_mssbuf;
1172
1173        err = alloc_queue("RX", lp->rx_num_entries,
1174                          &lp->rx_base, &lp->rx_ra);
1175        if (err)
1176                goto out_free_txq;
1177
1178        lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1179
1180        lp->hs_state = LDC_HS_CLOSED;
1181        ldc_set_state(lp, LDC_STATE_INIT);
1182
1183        INIT_HLIST_NODE(&lp->list);
1184        hlist_add_head(&lp->list, &ldc_channel_list);
1185
1186        INIT_HLIST_HEAD(&lp->mh_list);
1187
1188        return lp;
1189
1190out_free_txq:
1191        free_queue(lp->tx_num_entries, lp->tx_base);
1192
1193out_free_mssbuf:
1194        kfree(mssbuf);
1195
1196out_free_iommu:
1197        ldc_iommu_release(lp);
1198
1199out_free_ldc:
1200        kfree(lp);
1201
1202out_err:
1203        return ERR_PTR(err);
1204}
1205EXPORT_SYMBOL(ldc_alloc);
1206
1207void ldc_free(struct ldc_channel *lp)
1208{
1209        if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1210                free_irq(lp->cfg.rx_irq, lp);
1211                free_irq(lp->cfg.tx_irq, lp);
1212        }
1213
1214        if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1215                sun4v_ldc_tx_qconf(lp->id, 0, 0);
1216                sun4v_ldc_rx_qconf(lp->id, 0, 0);
1217                lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1218        }
1219        if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1220                free_queue(lp->tx_num_entries, lp->tx_base);
1221                free_queue(lp->rx_num_entries, lp->rx_base);
1222                lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1223        }
1224
1225        hlist_del(&lp->list);
1226
1227        kfree(lp->mssbuf);
1228
1229        ldc_iommu_release(lp);
1230
1231        kfree(lp);
1232}
1233EXPORT_SYMBOL(ldc_free);
1234
1235/* Bind the channel.  This registers the LDC queues with
1236 * the hypervisor and puts the channel into a pseudo-listening
1237 * state.  This does not initiate a handshake, ldc_connect() does
1238 * that.
1239 */
1240int ldc_bind(struct ldc_channel *lp, const char *name)
1241{
1242        unsigned long hv_err, flags;
1243        int err = -EINVAL;
1244
1245        if (!name ||
1246            (lp->state != LDC_STATE_INIT))
1247                return -EINVAL;
1248
1249        snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1250        snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1251
1252        err = request_irq(lp->cfg.rx_irq, ldc_rx, IRQF_DISABLED,
1253                          lp->rx_irq_name, lp);
1254        if (err)
1255                return err;
1256
1257        err = request_irq(lp->cfg.tx_irq, ldc_tx, IRQF_DISABLED,
1258                          lp->tx_irq_name, lp);
1259        if (err) {
1260                free_irq(lp->cfg.rx_irq, lp);
1261                return err;
1262        }
1263
1264
1265        spin_lock_irqsave(&lp->lock, flags);
1266
1267        enable_irq(lp->cfg.rx_irq);
1268        enable_irq(lp->cfg.tx_irq);
1269
1270        lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1271
1272        err = -ENODEV;
1273        hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1274        if (hv_err)
1275                goto out_free_irqs;
1276
1277        hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1278        if (hv_err)
1279                goto out_free_irqs;
1280
1281        hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1282        if (hv_err)
1283                goto out_unmap_tx;
1284
1285        hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1286        if (hv_err)
1287                goto out_unmap_tx;
1288
1289        lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1290
1291        hv_err = sun4v_ldc_tx_get_state(lp->id,
1292                                        &lp->tx_head,
1293                                        &lp->tx_tail,
1294                                        &lp->chan_state);
1295        err = -EBUSY;
1296        if (hv_err)
1297                goto out_unmap_rx;
1298
1299        lp->tx_acked = lp->tx_head;
1300
1301        lp->hs_state = LDC_HS_OPEN;
1302        ldc_set_state(lp, LDC_STATE_BOUND);
1303
1304        spin_unlock_irqrestore(&lp->lock, flags);
1305
1306        return 0;
1307
1308out_unmap_rx:
1309        lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1310        sun4v_ldc_rx_qconf(lp->id, 0, 0);
1311
1312out_unmap_tx:
1313        sun4v_ldc_tx_qconf(lp->id, 0, 0);
1314
1315out_free_irqs:
1316        lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1317        free_irq(lp->cfg.tx_irq, lp);
1318        free_irq(lp->cfg.rx_irq, lp);
1319
1320        spin_unlock_irqrestore(&lp->lock, flags);
1321
1322        return err;
1323}
1324EXPORT_SYMBOL(ldc_bind);
1325
1326int ldc_connect(struct ldc_channel *lp)
1327{
1328        unsigned long flags;
1329        int err;
1330
1331        if (lp->cfg.mode == LDC_MODE_RAW)
1332                return -EINVAL;
1333
1334        spin_lock_irqsave(&lp->lock, flags);
1335
1336        if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1337            !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1338            lp->hs_state != LDC_HS_OPEN)
1339                err = -EINVAL;
1340        else
1341                err = start_handshake(lp);
1342
1343        spin_unlock_irqrestore(&lp->lock, flags);
1344
1345        return err;
1346}
1347EXPORT_SYMBOL(ldc_connect);
1348
1349int ldc_disconnect(struct ldc_channel *lp)
1350{
1351        unsigned long hv_err, flags;
1352        int err;
1353
1354        if (lp->cfg.mode == LDC_MODE_RAW)
1355                return -EINVAL;
1356
1357        if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1358            !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1359                return -EINVAL;
1360
1361        spin_lock_irqsave(&lp->lock, flags);
1362
1363        err = -ENODEV;
1364        hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1365        if (hv_err)
1366                goto out_err;
1367
1368        hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1369        if (hv_err)
1370                goto out_err;
1371
1372        hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1373        if (hv_err)
1374                goto out_err;
1375
1376        hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1377        if (hv_err)
1378                goto out_err;
1379
1380        ldc_set_state(lp, LDC_STATE_BOUND);
1381        lp->hs_state = LDC_HS_OPEN;
1382        lp->flags |= LDC_FLAG_RESET;
1383
1384        spin_unlock_irqrestore(&lp->lock, flags);
1385
1386        return 0;
1387
1388out_err:
1389        sun4v_ldc_tx_qconf(lp->id, 0, 0);
1390        sun4v_ldc_rx_qconf(lp->id, 0, 0);
1391        free_irq(lp->cfg.tx_irq, lp);
1392        free_irq(lp->cfg.rx_irq, lp);
1393        lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1394                       LDC_FLAG_REGISTERED_QUEUES);
1395        ldc_set_state(lp, LDC_STATE_INIT);
1396
1397        spin_unlock_irqrestore(&lp->lock, flags);
1398
1399        return err;
1400}
1401EXPORT_SYMBOL(ldc_disconnect);
1402
1403int ldc_state(struct ldc_channel *lp)
1404{
1405        return lp->state;
1406}
1407EXPORT_SYMBOL(ldc_state);
1408
1409static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1410{
1411        struct ldc_packet *p;
1412        unsigned long new_tail;
1413        int err;
1414
1415        if (size > LDC_PACKET_SIZE)
1416                return -EMSGSIZE;
1417
1418        p = data_get_tx_packet(lp, &new_tail);
1419        if (!p)
1420                return -EAGAIN;
1421
1422        memcpy(p, buf, size);
1423
1424        err = send_tx_packet(lp, p, new_tail);
1425        if (!err)
1426                err = size;
1427
1428        return err;
1429}
1430
1431static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1432{
1433        struct ldc_packet *p;
1434        unsigned long hv_err, new;
1435        int err;
1436
1437        if (size < LDC_PACKET_SIZE)
1438                return -EINVAL;
1439
1440        hv_err = sun4v_ldc_rx_get_state(lp->id,
1441                                        &lp->rx_head,
1442                                        &lp->rx_tail,
1443                                        &lp->chan_state);
1444        if (hv_err)
1445                return ldc_abort(lp);
1446
1447        if (lp->chan_state == LDC_CHANNEL_DOWN ||
1448            lp->chan_state == LDC_CHANNEL_RESETTING)
1449                return -ECONNRESET;
1450
1451        if (lp->rx_head == lp->rx_tail)
1452                return 0;
1453
1454        p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1455        memcpy(buf, p, LDC_PACKET_SIZE);
1456
1457        new = rx_advance(lp, lp->rx_head);
1458        lp->rx_head = new;
1459
1460        err = __set_rx_head(lp, new);
1461        if (err < 0)
1462                err = -ECONNRESET;
1463        else
1464                err = LDC_PACKET_SIZE;
1465
1466        return err;
1467}
1468
1469static const struct ldc_mode_ops raw_ops = {
1470        .write          =       write_raw,
1471        .read           =       read_raw,
1472};
1473
1474static int write_nonraw(struct ldc_channel *lp, const void *buf,
1475                        unsigned int size)
1476{
1477        unsigned long hv_err, tail;
1478        unsigned int copied;
1479        u32 seq;
1480        int err;
1481
1482        hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1483                                        &lp->chan_state);
1484        if (unlikely(hv_err))
1485                return -EBUSY;
1486
1487        if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1488                return ldc_abort(lp);
1489
1490        if (!tx_has_space_for(lp, size))
1491                return -EAGAIN;
1492
1493        seq = lp->snd_nxt;
1494        copied = 0;
1495        tail = lp->tx_tail;
1496        while (copied < size) {
1497                struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1498                u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1499                            p->u.u_data :
1500                            p->u.r.r_data);
1501                int data_len;
1502
1503                p->type = LDC_DATA;
1504                p->stype = LDC_INFO;
1505                p->ctrl = 0;
1506
1507                data_len = size - copied;
1508                if (data_len > lp->mss)
1509                        data_len = lp->mss;
1510
1511                BUG_ON(data_len > LDC_LEN);
1512
1513                p->env = (data_len |
1514                          (copied == 0 ? LDC_START : 0) |
1515                          (data_len == size - copied ? LDC_STOP : 0));
1516
1517                p->seqid = ++seq;
1518
1519                ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1520                       p->type,
1521                       p->stype,
1522                       p->ctrl,
1523                       p->env,
1524                       p->seqid);
1525
1526                memcpy(data, buf, data_len);
1527                buf += data_len;
1528                copied += data_len;
1529
1530                tail = tx_advance(lp, tail);
1531        }
1532
1533        err = set_tx_tail(lp, tail);
1534        if (!err) {
1535                lp->snd_nxt = seq;
1536                err = size;
1537        }
1538
1539        return err;
1540}
1541
1542static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1543                      struct ldc_packet *first_frag)
1544{
1545        int err;
1546
1547        if (first_frag)
1548                lp->rcv_nxt = first_frag->seqid - 1;
1549
1550        err = send_data_nack(lp, p);
1551        if (err)
1552                return err;
1553
1554        err = __set_rx_head(lp, lp->rx_tail);
1555        if (err < 0)
1556                return ldc_abort(lp);
1557
1558        return 0;
1559}
1560
1561static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1562{
1563        if (p->stype & LDC_ACK) {
1564                int err = process_data_ack(lp, p);
1565                if (err)
1566                        return err;
1567        }
1568        if (p->stype & LDC_NACK)
1569                return ldc_abort(lp);
1570
1571        return 0;
1572}
1573
1574static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1575{
1576        unsigned long dummy;
1577        int limit = 1000;
1578
1579        ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1580               cur_head, lp->rx_head, lp->rx_tail);
1581        while (limit-- > 0) {
1582                unsigned long hv_err;
1583
1584                hv_err = sun4v_ldc_rx_get_state(lp->id,
1585                                                &dummy,
1586                                                &lp->rx_tail,
1587                                                &lp->chan_state);
1588                if (hv_err)
1589                        return ldc_abort(lp);
1590
1591                if (lp->chan_state == LDC_CHANNEL_DOWN ||
1592                    lp->chan_state == LDC_CHANNEL_RESETTING)
1593                        return -ECONNRESET;
1594
1595                if (cur_head != lp->rx_tail) {
1596                        ldcdbg(DATA, "DATA WAIT DONE "
1597                               "head[%lx] tail[%lx] chan_state[%lx]\n",
1598                               dummy, lp->rx_tail, lp->chan_state);
1599                        return 0;
1600                }
1601
1602                udelay(1);
1603        }
1604        return -EAGAIN;
1605}
1606
1607static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1608{
1609        int err = __set_rx_head(lp, head);
1610
1611        if (err < 0)
1612                return ldc_abort(lp);
1613
1614        lp->rx_head = head;
1615        return 0;
1616}
1617
1618static void send_data_ack(struct ldc_channel *lp)
1619{
1620        unsigned long new_tail;
1621        struct ldc_packet *p;
1622
1623        p = data_get_tx_packet(lp, &new_tail);
1624        if (likely(p)) {
1625                int err;
1626
1627                memset(p, 0, sizeof(*p));
1628                p->type = LDC_DATA;
1629                p->stype = LDC_ACK;
1630                p->ctrl = 0;
1631                p->seqid = lp->snd_nxt + 1;
1632                p->u.r.ackid = lp->rcv_nxt;
1633
1634                err = send_tx_packet(lp, p, new_tail);
1635                if (!err)
1636                        lp->snd_nxt++;
1637        }
1638}
1639
1640static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1641{
1642        struct ldc_packet *first_frag;
1643        unsigned long hv_err, new;
1644        int err, copied;
1645
1646        hv_err = sun4v_ldc_rx_get_state(lp->id,
1647                                        &lp->rx_head,
1648                                        &lp->rx_tail,
1649                                        &lp->chan_state);
1650        if (hv_err)
1651                return ldc_abort(lp);
1652
1653        if (lp->chan_state == LDC_CHANNEL_DOWN ||
1654            lp->chan_state == LDC_CHANNEL_RESETTING)
1655                return -ECONNRESET;
1656
1657        if (lp->rx_head == lp->rx_tail)
1658                return 0;
1659
1660        first_frag = NULL;
1661        copied = err = 0;
1662        new = lp->rx_head;
1663        while (1) {
1664                struct ldc_packet *p;
1665                int pkt_len;
1666
1667                BUG_ON(new == lp->rx_tail);
1668                p = lp->rx_base + (new / LDC_PACKET_SIZE);
1669
1670                ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1671                       "rcv_nxt[%08x]\n",
1672                       p->type,
1673                       p->stype,
1674                       p->ctrl,
1675                       p->env,
1676                       p->seqid,
1677                       p->u.r.ackid,
1678                       lp->rcv_nxt);
1679
1680                if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1681                        err = rx_bad_seq(lp, p, first_frag);
1682                        copied = 0;
1683                        break;
1684                }
1685
1686                if (p->type & LDC_CTRL) {
1687                        err = process_control_frame(lp, p);
1688                        if (err < 0)
1689                                break;
1690                        err = 0;
1691                }
1692
1693                lp->rcv_nxt = p->seqid;
1694
1695                if (!(p->type & LDC_DATA)) {
1696                        new = rx_advance(lp, new);
1697                        goto no_data;
1698                }
1699                if (p->stype & (LDC_ACK | LDC_NACK)) {
1700                        err = data_ack_nack(lp, p);
1701                        if (err)
1702                                break;
1703                }
1704                if (!(p->stype & LDC_INFO)) {
1705                        new = rx_advance(lp, new);
1706                        err = rx_set_head(lp, new);
1707                        if (err)
1708                                break;
1709                        goto no_data;
1710                }
1711
1712                pkt_len = p->env & LDC_LEN;
1713
1714                /* Every initial packet starts with the START bit set.
1715                 *
1716                 * Singleton packets will have both START+STOP set.
1717                 *
1718                 * Fragments will have START set in the first frame, STOP
1719                 * set in the last frame, and neither bit set in middle
1720                 * frames of the packet.
1721                 *
1722                 * Therefore if we are at the beginning of a packet and
1723                 * we don't see START, or we are in the middle of a fragmented
1724                 * packet and do see START, we are unsynchronized and should
1725                 * flush the RX queue.
1726                 */
1727                if ((first_frag == NULL && !(p->env & LDC_START)) ||
1728                    (first_frag != NULL &&  (p->env & LDC_START))) {
1729                        if (!first_frag)
1730                                new = rx_advance(lp, new);
1731
1732                        err = rx_set_head(lp, new);
1733                        if (err)
1734                                break;
1735
1736                        if (!first_frag)
1737                                goto no_data;
1738                }
1739                if (!first_frag)
1740                        first_frag = p;
1741
1742                if (pkt_len > size - copied) {
1743                        /* User didn't give us a big enough buffer,
1744                         * what to do?  This is a pretty serious error.
1745                         *
1746                         * Since we haven't updated the RX ring head to
1747                         * consume any of the packets, signal the error
1748                         * to the user and just leave the RX ring alone.
1749                         *
1750                         * This seems the best behavior because this allows
1751                         * a user of the LDC layer to start with a small
1752                         * RX buffer for ldc_read() calls and use -EMSGSIZE
1753                         * as a cue to enlarge it's read buffer.
1754                         */
1755                        err = -EMSGSIZE;
1756                        break;
1757                }
1758
1759                /* Ok, we are gonna eat this one.  */
1760                new = rx_advance(lp, new);
1761
1762                memcpy(buf,
1763                       (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1764                        p->u.u_data : p->u.r.r_data), pkt_len);
1765                buf += pkt_len;
1766                copied += pkt_len;
1767
1768                if (p->env & LDC_STOP)
1769                        break;
1770
1771no_data:
1772                if (new == lp->rx_tail) {
1773                        err = rx_data_wait(lp, new);
1774                        if (err)
1775                                break;
1776                }
1777        }
1778
1779        if (!err)
1780                err = rx_set_head(lp, new);
1781
1782        if (err && first_frag)
1783                lp->rcv_nxt = first_frag->seqid - 1;
1784
1785        if (!err) {
1786                err = copied;
1787                if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1788                        send_data_ack(lp);
1789        }
1790
1791        return err;
1792}
1793
1794static const struct ldc_mode_ops nonraw_ops = {
1795        .write          =       write_nonraw,
1796        .read           =       read_nonraw,
1797};
1798
1799static int write_stream(struct ldc_channel *lp, const void *buf,
1800                        unsigned int size)
1801{
1802        if (size > lp->cfg.mtu)
1803                size = lp->cfg.mtu;
1804        return write_nonraw(lp, buf, size);
1805}
1806
1807static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1808{
1809        if (!lp->mssbuf_len) {
1810                int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1811                if (err < 0)
1812                        return err;
1813
1814                lp->mssbuf_len = err;
1815                lp->mssbuf_off = 0;
1816        }
1817
1818        if (size > lp->mssbuf_len)
1819                size = lp->mssbuf_len;
1820        memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1821
1822        lp->mssbuf_off += size;
1823        lp->mssbuf_len -= size;
1824
1825        return size;
1826}
1827
1828static const struct ldc_mode_ops stream_ops = {
1829        .write          =       write_stream,
1830        .read           =       read_stream,
1831};
1832
1833int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1834{
1835        unsigned long flags;
1836        int err;
1837
1838        if (!buf)
1839                return -EINVAL;
1840
1841        if (!size)
1842                return 0;
1843
1844        spin_lock_irqsave(&lp->lock, flags);
1845
1846        if (lp->hs_state != LDC_HS_COMPLETE)
1847                err = -ENOTCONN;
1848        else
1849                err = lp->mops->write(lp, buf, size);
1850
1851        spin_unlock_irqrestore(&lp->lock, flags);
1852
1853        return err;
1854}
1855EXPORT_SYMBOL(ldc_write);
1856
1857int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1858{
1859        unsigned long flags;
1860        int err;
1861
1862        if (!buf)
1863                return -EINVAL;
1864
1865        if (!size)
1866                return 0;
1867
1868        spin_lock_irqsave(&lp->lock, flags);
1869
1870        if (lp->hs_state != LDC_HS_COMPLETE)
1871                err = -ENOTCONN;
1872        else
1873                err = lp->mops->read(lp, buf, size);
1874
1875        spin_unlock_irqrestore(&lp->lock, flags);
1876
1877        return err;
1878}
1879EXPORT_SYMBOL(ldc_read);
1880
1881static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1882{
1883        struct iommu_arena *arena = &iommu->arena;
1884        unsigned long n, start, end, limit;
1885        int pass;
1886
1887        limit = arena->limit;
1888        start = arena->hint;
1889        pass = 0;
1890
1891again:
1892        n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
1893        end = n + npages;
1894        if (unlikely(end >= limit)) {
1895                if (likely(pass < 1)) {
1896                        limit = start;
1897                        start = 0;
1898                        pass++;
1899                        goto again;
1900                } else {
1901                        /* Scanned the whole thing, give up. */
1902                        return -1;
1903                }
1904        }
1905        bitmap_set(arena->map, n, npages);
1906
1907        arena->hint = end;
1908
1909        return n;
1910}
1911
1912#define COOKIE_PGSZ_CODE        0xf000000000000000ULL
1913#define COOKIE_PGSZ_CODE_SHIFT  60ULL
1914
1915static u64 pagesize_code(void)
1916{
1917        switch (PAGE_SIZE) {
1918        default:
1919        case (8ULL * 1024ULL):
1920                return 0;
1921        case (64ULL * 1024ULL):
1922                return 1;
1923        case (512ULL * 1024ULL):
1924                return 2;
1925        case (4ULL * 1024ULL * 1024ULL):
1926                return 3;
1927        case (32ULL * 1024ULL * 1024ULL):
1928                return 4;
1929        case (256ULL * 1024ULL * 1024ULL):
1930                return 5;
1931        }
1932}
1933
1934static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1935{
1936        return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1937                (index << PAGE_SHIFT) |
1938                page_offset);
1939}
1940
1941static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1942{
1943        u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1944
1945        cookie &= ~COOKIE_PGSZ_CODE;
1946
1947        *shift = szcode * 3;
1948
1949        return (cookie >> (13ULL + (szcode * 3ULL)));
1950}
1951
1952static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1953                                             unsigned long npages)
1954{
1955        long entry;
1956
1957        entry = arena_alloc(iommu, npages);
1958        if (unlikely(entry < 0))
1959                return NULL;
1960
1961        return iommu->page_table + entry;
1962}
1963
1964static u64 perm_to_mte(unsigned int map_perm)
1965{
1966        u64 mte_base;
1967
1968        mte_base = pagesize_code();
1969
1970        if (map_perm & LDC_MAP_SHADOW) {
1971                if (map_perm & LDC_MAP_R)
1972                        mte_base |= LDC_MTE_COPY_R;
1973                if (map_perm & LDC_MAP_W)
1974                        mte_base |= LDC_MTE_COPY_W;
1975        }
1976        if (map_perm & LDC_MAP_DIRECT) {
1977                if (map_perm & LDC_MAP_R)
1978                        mte_base |= LDC_MTE_READ;
1979                if (map_perm & LDC_MAP_W)
1980                        mte_base |= LDC_MTE_WRITE;
1981                if (map_perm & LDC_MAP_X)
1982                        mte_base |= LDC_MTE_EXEC;
1983        }
1984        if (map_perm & LDC_MAP_IO) {
1985                if (map_perm & LDC_MAP_R)
1986                        mte_base |= LDC_MTE_IOMMU_R;
1987                if (map_perm & LDC_MAP_W)
1988                        mte_base |= LDC_MTE_IOMMU_W;
1989        }
1990
1991        return mte_base;
1992}
1993
1994static int pages_in_region(unsigned long base, long len)
1995{
1996        int count = 0;
1997
1998        do {
1999                unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
2000
2001                len -= (new - base);
2002                base = new;
2003                count++;
2004        } while (len > 0);
2005
2006        return count;
2007}
2008
2009struct cookie_state {
2010        struct ldc_mtable_entry         *page_table;
2011        struct ldc_trans_cookie         *cookies;
2012        u64                             mte_base;
2013        u64                             prev_cookie;
2014        u32                             pte_idx;
2015        u32                             nc;
2016};
2017
2018static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2019                         unsigned long off, unsigned long len)
2020{
2021        do {
2022                unsigned long tlen, new = pa + PAGE_SIZE;
2023                u64 this_cookie;
2024
2025                sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2026
2027                tlen = PAGE_SIZE;
2028                if (off)
2029                        tlen = PAGE_SIZE - off;
2030                if (tlen > len)
2031                        tlen = len;
2032
2033                this_cookie = make_cookie(sp->pte_idx,
2034                                          pagesize_code(), off);
2035
2036                off = 0;
2037
2038                if (this_cookie == sp->prev_cookie) {
2039                        sp->cookies[sp->nc - 1].cookie_size += tlen;
2040                } else {
2041                        sp->cookies[sp->nc].cookie_addr = this_cookie;
2042                        sp->cookies[sp->nc].cookie_size = tlen;
2043                        sp->nc++;
2044                }
2045                sp->prev_cookie = this_cookie + tlen;
2046
2047                sp->pte_idx++;
2048
2049                len -= tlen;
2050                pa = new;
2051        } while (len > 0);
2052}
2053
2054static int sg_count_one(struct scatterlist *sg)
2055{
2056        unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2057        long len = sg->length;
2058
2059        if ((sg->offset | len) & (8UL - 1))
2060                return -EFAULT;
2061
2062        return pages_in_region(base + sg->offset, len);
2063}
2064
2065static int sg_count_pages(struct scatterlist *sg, int num_sg)
2066{
2067        int count;
2068        int i;
2069
2070        count = 0;
2071        for (i = 0; i < num_sg; i++) {
2072                int err = sg_count_one(sg + i);
2073                if (err < 0)
2074                        return err;
2075                count += err;
2076        }
2077
2078        return count;
2079}
2080
2081int ldc_map_sg(struct ldc_channel *lp,
2082               struct scatterlist *sg, int num_sg,
2083               struct ldc_trans_cookie *cookies, int ncookies,
2084               unsigned int map_perm)
2085{
2086        unsigned long i, npages, flags;
2087        struct ldc_mtable_entry *base;
2088        struct cookie_state state;
2089        struct ldc_iommu *iommu;
2090        int err;
2091
2092        if (map_perm & ~LDC_MAP_ALL)
2093                return -EINVAL;
2094
2095        err = sg_count_pages(sg, num_sg);
2096        if (err < 0)
2097                return err;
2098
2099        npages = err;
2100        if (err > ncookies)
2101                return -EMSGSIZE;
2102
2103        iommu = &lp->iommu;
2104
2105        spin_lock_irqsave(&iommu->lock, flags);
2106        base = alloc_npages(iommu, npages);
2107        spin_unlock_irqrestore(&iommu->lock, flags);
2108
2109        if (!base)
2110                return -ENOMEM;
2111
2112        state.page_table = iommu->page_table;
2113        state.cookies = cookies;
2114        state.mte_base = perm_to_mte(map_perm);
2115        state.prev_cookie = ~(u64)0;
2116        state.pte_idx = (base - iommu->page_table);
2117        state.nc = 0;
2118
2119        for (i = 0; i < num_sg; i++)
2120                fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2121                             sg[i].offset, sg[i].length);
2122
2123        return state.nc;
2124}
2125EXPORT_SYMBOL(ldc_map_sg);
2126
2127int ldc_map_single(struct ldc_channel *lp,
2128                   void *buf, unsigned int len,
2129                   struct ldc_trans_cookie *cookies, int ncookies,
2130                   unsigned int map_perm)
2131{
2132        unsigned long npages, pa, flags;
2133        struct ldc_mtable_entry *base;
2134        struct cookie_state state;
2135        struct ldc_iommu *iommu;
2136
2137        if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2138                return -EINVAL;
2139
2140        pa = __pa(buf);
2141        if ((pa | len) & (8UL - 1))
2142                return -EFAULT;
2143
2144        npages = pages_in_region(pa, len);
2145
2146        iommu = &lp->iommu;
2147
2148        spin_lock_irqsave(&iommu->lock, flags);
2149        base = alloc_npages(iommu, npages);
2150        spin_unlock_irqrestore(&iommu->lock, flags);
2151
2152        if (!base)
2153                return -ENOMEM;
2154
2155        state.page_table = iommu->page_table;
2156        state.cookies = cookies;
2157        state.mte_base = perm_to_mte(map_perm);
2158        state.prev_cookie = ~(u64)0;
2159        state.pte_idx = (base - iommu->page_table);
2160        state.nc = 0;
2161        fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2162        BUG_ON(state.nc != 1);
2163
2164        return state.nc;
2165}
2166EXPORT_SYMBOL(ldc_map_single);
2167
2168static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2169                        u64 cookie, u64 size)
2170{
2171        struct iommu_arena *arena = &iommu->arena;
2172        unsigned long i, shift, index, npages;
2173        struct ldc_mtable_entry *base;
2174
2175        npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2176        index = cookie_to_index(cookie, &shift);
2177        base = iommu->page_table + index;
2178
2179        BUG_ON(index > arena->limit ||
2180               (index + npages) > arena->limit);
2181
2182        for (i = 0; i < npages; i++) {
2183                if (base->cookie)
2184                        sun4v_ldc_revoke(id, cookie + (i << shift),
2185                                         base->cookie);
2186                base->mte = 0;
2187                __clear_bit(index + i, arena->map);
2188        }
2189}
2190
2191void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2192               int ncookies)
2193{
2194        struct ldc_iommu *iommu = &lp->iommu;
2195        unsigned long flags;
2196        int i;
2197
2198        spin_lock_irqsave(&iommu->lock, flags);
2199        for (i = 0; i < ncookies; i++) {
2200                u64 addr = cookies[i].cookie_addr;
2201                u64 size = cookies[i].cookie_size;
2202
2203                free_npages(lp->id, iommu, addr, size);
2204        }
2205        spin_unlock_irqrestore(&iommu->lock, flags);
2206}
2207EXPORT_SYMBOL(ldc_unmap);
2208
2209int ldc_copy(struct ldc_channel *lp, int copy_dir,
2210             void *buf, unsigned int len, unsigned long offset,
2211             struct ldc_trans_cookie *cookies, int ncookies)
2212{
2213        unsigned int orig_len;
2214        unsigned long ra;
2215        int i;
2216
2217        if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2218                printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2219                       lp->id, copy_dir);
2220                return -EINVAL;
2221        }
2222
2223        ra = __pa(buf);
2224        if ((ra | len | offset) & (8UL - 1)) {
2225                printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2226                       "ra[%lx] len[%x] offset[%lx]\n",
2227                       lp->id, ra, len, offset);
2228                return -EFAULT;
2229        }
2230
2231        if (lp->hs_state != LDC_HS_COMPLETE ||
2232            (lp->flags & LDC_FLAG_RESET)) {
2233                printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2234                       "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2235                return -ECONNRESET;
2236        }
2237
2238        orig_len = len;
2239        for (i = 0; i < ncookies; i++) {
2240                unsigned long cookie_raddr = cookies[i].cookie_addr;
2241                unsigned long this_len = cookies[i].cookie_size;
2242                unsigned long actual_len;
2243
2244                if (unlikely(offset)) {
2245                        unsigned long this_off = offset;
2246
2247                        if (this_off > this_len)
2248                                this_off = this_len;
2249
2250                        offset -= this_off;
2251                        this_len -= this_off;
2252                        if (!this_len)
2253                                continue;
2254                        cookie_raddr += this_off;
2255                }
2256
2257                if (this_len > len)
2258                        this_len = len;
2259
2260                while (1) {
2261                        unsigned long hv_err;
2262
2263                        hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2264                                                cookie_raddr, ra,
2265                                                this_len, &actual_len);
2266                        if (unlikely(hv_err)) {
2267                                printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2268                                       "HV error %lu\n",
2269                                       lp->id, hv_err);
2270                                if (lp->hs_state != LDC_HS_COMPLETE ||
2271                                    (lp->flags & LDC_FLAG_RESET))
2272                                        return -ECONNRESET;
2273                                else
2274                                        return -EFAULT;
2275                        }
2276
2277                        cookie_raddr += actual_len;
2278                        ra += actual_len;
2279                        len -= actual_len;
2280                        if (actual_len == this_len)
2281                                break;
2282
2283                        this_len -= actual_len;
2284                }
2285
2286                if (!len)
2287                        break;
2288        }
2289
2290        /* It is caller policy what to do about short copies.
2291         * For example, a networking driver can declare the
2292         * packet a runt and drop it.
2293         */
2294
2295        return orig_len - len;
2296}
2297EXPORT_SYMBOL(ldc_copy);
2298
2299void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2300                          struct ldc_trans_cookie *cookies, int *ncookies,
2301                          unsigned int map_perm)
2302{
2303        void *buf;
2304        int err;
2305
2306        if (len & (8UL - 1))
2307                return ERR_PTR(-EINVAL);
2308
2309        buf = kzalloc(len, GFP_KERNEL);
2310        if (!buf)
2311                return ERR_PTR(-ENOMEM);
2312
2313        err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2314        if (err < 0) {
2315                kfree(buf);
2316                return ERR_PTR(err);
2317        }
2318        *ncookies = err;
2319
2320        return buf;
2321}
2322EXPORT_SYMBOL(ldc_alloc_exp_dring);
2323
2324void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2325                        struct ldc_trans_cookie *cookies, int ncookies)
2326{
2327        ldc_unmap(lp, cookies, ncookies);
2328        kfree(buf);
2329}
2330EXPORT_SYMBOL(ldc_free_exp_dring);
2331
2332static int __init ldc_init(void)
2333{
2334        unsigned long major, minor;
2335        struct mdesc_handle *hp;
2336        const u64 *v;
2337        int err;
2338        u64 mp;
2339
2340        hp = mdesc_grab();
2341        if (!hp)
2342                return -ENODEV;
2343
2344        mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2345        err = -ENODEV;
2346        if (mp == MDESC_NODE_NULL)
2347                goto out;
2348
2349        v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2350        if (!v)
2351                goto out;
2352
2353        major = 1;
2354        minor = 0;
2355        if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2356                printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2357                goto out;
2358        }
2359
2360        printk(KERN_INFO "%s", version);
2361
2362        if (!*v) {
2363                printk(KERN_INFO PFX "Domaining disabled.\n");
2364                goto out;
2365        }
2366        ldom_domaining_enabled = 1;
2367        err = 0;
2368
2369out:
2370        mdesc_release(hp);
2371        return err;
2372}
2373
2374core_initcall(ldc_init);
2375