linux/arch/sparc/kernel/ldc.c
<<
>>
Prefs
   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
  29static 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 */
  37struct 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
  73struct ldc_version {
  74        u16 major;
  75        u16 minor;
  76};
  77
  78/* Ordered from largest major to lowest.  */
  79static 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
  86struct ldc_channel;
  87
  88struct ldc_mode_ops {
  89        int (*write)(struct ldc_channel *, const void *, unsigned int);
  90        int (*read)(struct ldc_channel *, void *, unsigned int);
  91};
  92
  93static const struct ldc_mode_ops raw_ops;
  94static const struct ldc_mode_ops nonraw_ops;
  95static const struct ldc_mode_ops stream_ops;
  96
  97int ldom_domaining_enabled;
  98
  99struct 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
 106struct 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...) \
 171do {    if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
 172                printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
 173} while (0)
 174
 175static 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
 193static 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
 202static 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
 211static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
 212{
 213        return __advance(off, lp->rx_num_entries);
 214}
 215
 216static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
 217{
 218        return __advance(off, lp->tx_num_entries);
 219}
 220
 221static 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 */
 244static 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
 251static 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
 276static 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
 293static 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 */
 321static 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
 341static 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
 350static 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
 368static 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
 390static 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
 411static 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
 428static 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
 448static 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
 467static 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
 487static 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
 513static 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
 558static 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
 573static 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
 607static 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
 625static 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
 647static 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
 669static 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
 689static 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
 707static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
 708{
 709        return lp->rcv_nxt + 1 == seqid;
 710}
 711
 712static 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
 730static 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
 751static int process_error_frame(struct ldc_channel *lp,
 752                               struct ldc_packet *p)
 753{
 754        return ldc_abort(lp);
 755}
 756
 757static 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
 779static 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
 789static 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) {
 831handshake_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
 895out:
 896        spin_unlock_irqrestore(&lp->lock, flags);
 897
 898        send_events(lp, event_mask);
 899
 900        return IRQ_HANDLED;
 901}
 902
 903static 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 */
 942static HLIST_HEAD(ldc_channel_list);
 943
 944static 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
 956static 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
 980static 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
 996static 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
1042out_free_table:
1043        free_pages((unsigned long) table, order);
1044        iommu->page_table = NULL;
1045
1046out_free_map:
1047        kfree(iommu->arena.map);
1048        iommu->arena.map = NULL;
1049
1050        return err;
1051}
1052
1053static 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
1071struct 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
1182out_free_txq:
1183        free_queue(lp->tx_num_entries, lp->tx_base);
1184
1185out_free_mssbuf:
1186        kfree(mssbuf);
1187
1188out_free_iommu:
1189        ldc_iommu_release(lp);
1190
1191out_free_ldc:
1192        kfree(lp);
1193
1194out_err:
1195        return ERR_PTR(err);
1196}
1197EXPORT_SYMBOL(ldc_alloc);
1198
1199void 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}
1225EXPORT_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 */
1232int 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_DISABLED | 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_DISABLED | 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
1302out_unmap_rx:
1303        lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1304        sun4v_ldc_rx_qconf(lp->id, 0, 0);
1305
1306out_unmap_tx:
1307        sun4v_ldc_tx_qconf(lp->id, 0, 0);
1308
1309out_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}
1318EXPORT_SYMBOL(ldc_bind);
1319
1320int 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}
1341EXPORT_SYMBOL(ldc_connect);
1342
1343int 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
1382out_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}
1395EXPORT_SYMBOL(ldc_disconnect);
1396
1397int ldc_state(struct ldc_channel *lp)
1398{
1399        return lp->state;
1400}
1401EXPORT_SYMBOL(ldc_state);
1402
1403static 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
1425static 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
1463static const struct ldc_mode_ops raw_ops = {
1464        .write          =       write_raw,
1465        .read           =       read_raw,
1466};
1467
1468static 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
1536static 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
1555static 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
1568static 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
1601static 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
1612static 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
1634static 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
1765no_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
1788static const struct ldc_mode_ops nonraw_ops = {
1789        .write          =       write_nonraw,
1790        .read           =       read_nonraw,
1791};
1792
1793static 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
1801static 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
1822static const struct ldc_mode_ops stream_ops = {
1823        .write          =       write_stream,
1824        .read           =       read_stream,
1825};
1826
1827int 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}
1849EXPORT_SYMBOL(ldc_write);
1850
1851int 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}
1873EXPORT_SYMBOL(ldc_read);
1874
1875static 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
1885again:
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
1918static 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
1937static 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
1944static 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
1955static 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
1967static 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
1997static 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
2012struct 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
2021static 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
2057static 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
2068static 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
2084int 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}
2128EXPORT_SYMBOL(ldc_map_sg);
2129
2130int 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}
2169EXPORT_SYMBOL(ldc_map_single);
2170
2171static 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
2194void 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}
2210EXPORT_SYMBOL(ldc_unmap);
2211
2212int 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}
2300EXPORT_SYMBOL(ldc_copy);
2301
2302void *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}
2325EXPORT_SYMBOL(ldc_alloc_exp_dring);
2326
2327void 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}
2333EXPORT_SYMBOL(ldc_free_exp_dring);
2334
2335static 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
2372out:
2373        mdesc_release(hp);
2374        return err;
2375}
2376
2377core_initcall(ldc_init);
2378