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        struct hlist_node *n;
 957
 958        hlist_for_each_entry(lp, n, &ldc_channel_list, list) {
 959                if (lp->id == id)
 960                        return 1;
 961        }
 962        return 0;
 963}
 964
 965static int alloc_queue(const char *name, unsigned long num_entries,
 966                       struct ldc_packet **base, unsigned long *ra)
 967{
 968        unsigned long size, order;
 969        void *q;
 970
 971        size = num_entries * LDC_PACKET_SIZE;
 972        order = get_order(size);
 973
 974        q = (void *) __get_free_pages(GFP_KERNEL, order);
 975        if (!q) {
 976                printk(KERN_ERR PFX "Alloc of %s queue failed with "
 977                       "size=%lu order=%lu\n", name, size, order);
 978                return -ENOMEM;
 979        }
 980
 981        memset(q, 0, PAGE_SIZE << order);
 982
 983        *base = q;
 984        *ra = __pa(q);
 985
 986        return 0;
 987}
 988
 989static void free_queue(unsigned long num_entries, struct ldc_packet *q)
 990{
 991        unsigned long size, order;
 992
 993        if (!q)
 994                return;
 995
 996        size = num_entries * LDC_PACKET_SIZE;
 997        order = get_order(size);
 998
 999        free_pages((unsigned long)q, order);
1000}
1001
1002/* XXX Make this configurable... XXX */
1003#define LDC_IOTABLE_SIZE        (8 * 1024)
1004
1005static int ldc_iommu_init(struct ldc_channel *lp)
1006{
1007        unsigned long sz, num_tsb_entries, tsbsize, order;
1008        struct ldc_iommu *iommu = &lp->iommu;
1009        struct ldc_mtable_entry *table;
1010        unsigned long hv_err;
1011        int err;
1012
1013        num_tsb_entries = LDC_IOTABLE_SIZE;
1014        tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1015
1016        spin_lock_init(&iommu->lock);
1017
1018        sz = num_tsb_entries / 8;
1019        sz = (sz + 7UL) & ~7UL;
1020        iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1021        if (!iommu->arena.map) {
1022                printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1023                return -ENOMEM;
1024        }
1025
1026        iommu->arena.limit = num_tsb_entries;
1027
1028        order = get_order(tsbsize);
1029
1030        table = (struct ldc_mtable_entry *)
1031                __get_free_pages(GFP_KERNEL, order);
1032        err = -ENOMEM;
1033        if (!table) {
1034                printk(KERN_ERR PFX "Alloc of MTE table failed, "
1035                       "size=%lu order=%lu\n", tsbsize, order);
1036                goto out_free_map;
1037        }
1038
1039        memset(table, 0, PAGE_SIZE << order);
1040
1041        iommu->page_table = table;
1042
1043        hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1044                                         num_tsb_entries);
1045        err = -EINVAL;
1046        if (hv_err)
1047                goto out_free_table;
1048
1049        return 0;
1050
1051out_free_table:
1052        free_pages((unsigned long) table, order);
1053        iommu->page_table = NULL;
1054
1055out_free_map:
1056        kfree(iommu->arena.map);
1057        iommu->arena.map = NULL;
1058
1059        return err;
1060}
1061
1062static void ldc_iommu_release(struct ldc_channel *lp)
1063{
1064        struct ldc_iommu *iommu = &lp->iommu;
1065        unsigned long num_tsb_entries, tsbsize, order;
1066
1067        (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1068
1069        num_tsb_entries = iommu->arena.limit;
1070        tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1071        order = get_order(tsbsize);
1072
1073        free_pages((unsigned long) iommu->page_table, order);
1074        iommu->page_table = NULL;
1075
1076        kfree(iommu->arena.map);
1077        iommu->arena.map = NULL;
1078}
1079
1080struct ldc_channel *ldc_alloc(unsigned long id,
1081                              const struct ldc_channel_config *cfgp,
1082                              void *event_arg)
1083{
1084        struct ldc_channel *lp;
1085        const struct ldc_mode_ops *mops;
1086        unsigned long dummy1, dummy2, hv_err;
1087        u8 mss, *mssbuf;
1088        int err;
1089
1090        err = -ENODEV;
1091        if (!ldom_domaining_enabled)
1092                goto out_err;
1093
1094        err = -EINVAL;
1095        if (!cfgp)
1096                goto out_err;
1097
1098        switch (cfgp->mode) {
1099        case LDC_MODE_RAW:
1100                mops = &raw_ops;
1101                mss = LDC_PACKET_SIZE;
1102                break;
1103
1104        case LDC_MODE_UNRELIABLE:
1105                mops = &nonraw_ops;
1106                mss = LDC_PACKET_SIZE - 8;
1107                break;
1108
1109        case LDC_MODE_STREAM:
1110                mops = &stream_ops;
1111                mss = LDC_PACKET_SIZE - 8 - 8;
1112                break;
1113
1114        default:
1115                goto out_err;
1116        }
1117
1118        if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1119                goto out_err;
1120
1121        hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1122        err = -ENODEV;
1123        if (hv_err == HV_ECHANNEL)
1124                goto out_err;
1125
1126        err = -EEXIST;
1127        if (__ldc_channel_exists(id))
1128                goto out_err;
1129
1130        mssbuf = NULL;
1131
1132        lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1133        err = -ENOMEM;
1134        if (!lp)
1135                goto out_err;
1136
1137        spin_lock_init(&lp->lock);
1138
1139        lp->id = id;
1140
1141        err = ldc_iommu_init(lp);
1142        if (err)
1143                goto out_free_ldc;
1144
1145        lp->mops = mops;
1146        lp->mss = mss;
1147
1148        lp->cfg = *cfgp;
1149        if (!lp->cfg.mtu)
1150                lp->cfg.mtu = LDC_DEFAULT_MTU;
1151
1152        if (lp->cfg.mode == LDC_MODE_STREAM) {
1153                mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1154                if (!mssbuf) {
1155                        err = -ENOMEM;
1156                        goto out_free_iommu;
1157                }
1158                lp->mssbuf = mssbuf;
1159        }
1160
1161        lp->event_arg = event_arg;
1162
1163        /* XXX allow setting via ldc_channel_config to override defaults
1164         * XXX or use some formula based upon mtu
1165         */
1166        lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1167        lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1168
1169        err = alloc_queue("TX", lp->tx_num_entries,
1170                          &lp->tx_base, &lp->tx_ra);
1171        if (err)
1172                goto out_free_mssbuf;
1173
1174        err = alloc_queue("RX", lp->rx_num_entries,
1175                          &lp->rx_base, &lp->rx_ra);
1176        if (err)
1177                goto out_free_txq;
1178
1179        lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1180
1181        lp->hs_state = LDC_HS_CLOSED;
1182        ldc_set_state(lp, LDC_STATE_INIT);
1183
1184        INIT_HLIST_NODE(&lp->list);
1185        hlist_add_head(&lp->list, &ldc_channel_list);
1186
1187        INIT_HLIST_HEAD(&lp->mh_list);
1188
1189        return lp;
1190
1191out_free_txq:
1192        free_queue(lp->tx_num_entries, lp->tx_base);
1193
1194out_free_mssbuf:
1195        kfree(mssbuf);
1196
1197out_free_iommu:
1198        ldc_iommu_release(lp);
1199
1200out_free_ldc:
1201        kfree(lp);
1202
1203out_err:
1204        return ERR_PTR(err);
1205}
1206EXPORT_SYMBOL(ldc_alloc);
1207
1208void ldc_free(struct ldc_channel *lp)
1209{
1210        if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1211                free_irq(lp->cfg.rx_irq, lp);
1212                free_irq(lp->cfg.tx_irq, lp);
1213        }
1214
1215        if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1216                sun4v_ldc_tx_qconf(lp->id, 0, 0);
1217                sun4v_ldc_rx_qconf(lp->id, 0, 0);
1218                lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1219        }
1220        if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1221                free_queue(lp->tx_num_entries, lp->tx_base);
1222                free_queue(lp->rx_num_entries, lp->rx_base);
1223                lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1224        }
1225
1226        hlist_del(&lp->list);
1227
1228        kfree(lp->mssbuf);
1229
1230        ldc_iommu_release(lp);
1231
1232        kfree(lp);
1233}
1234EXPORT_SYMBOL(ldc_free);
1235
1236/* Bind the channel.  This registers the LDC queues with
1237 * the hypervisor and puts the channel into a pseudo-listening
1238 * state.  This does not initiate a handshake, ldc_connect() does
1239 * that.
1240 */
1241int ldc_bind(struct ldc_channel *lp, const char *name)
1242{
1243        unsigned long hv_err, flags;
1244        int err = -EINVAL;
1245
1246        if (!name ||
1247            (lp->state != LDC_STATE_INIT))
1248                return -EINVAL;
1249
1250        snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1251        snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1252
1253        err = request_irq(lp->cfg.rx_irq, ldc_rx, IRQF_DISABLED,
1254                          lp->rx_irq_name, lp);
1255        if (err)
1256                return err;
1257
1258        err = request_irq(lp->cfg.tx_irq, ldc_tx, IRQF_DISABLED,
1259                          lp->tx_irq_name, lp);
1260        if (err) {
1261                free_irq(lp->cfg.rx_irq, lp);
1262                return err;
1263        }
1264
1265
1266        spin_lock_irqsave(&lp->lock, flags);
1267
1268        enable_irq(lp->cfg.rx_irq);
1269        enable_irq(lp->cfg.tx_irq);
1270
1271        lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1272
1273        err = -ENODEV;
1274        hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1275        if (hv_err)
1276                goto out_free_irqs;
1277
1278        hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1279        if (hv_err)
1280                goto out_free_irqs;
1281
1282        hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1283        if (hv_err)
1284                goto out_unmap_tx;
1285
1286        hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1287        if (hv_err)
1288                goto out_unmap_tx;
1289
1290        lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1291
1292        hv_err = sun4v_ldc_tx_get_state(lp->id,
1293                                        &lp->tx_head,
1294                                        &lp->tx_tail,
1295                                        &lp->chan_state);
1296        err = -EBUSY;
1297        if (hv_err)
1298                goto out_unmap_rx;
1299
1300        lp->tx_acked = lp->tx_head;
1301
1302        lp->hs_state = LDC_HS_OPEN;
1303        ldc_set_state(lp, LDC_STATE_BOUND);
1304
1305        spin_unlock_irqrestore(&lp->lock, flags);
1306
1307        return 0;
1308
1309out_unmap_rx:
1310        lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1311        sun4v_ldc_rx_qconf(lp->id, 0, 0);
1312
1313out_unmap_tx:
1314        sun4v_ldc_tx_qconf(lp->id, 0, 0);
1315
1316out_free_irqs:
1317        lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1318        free_irq(lp->cfg.tx_irq, lp);
1319        free_irq(lp->cfg.rx_irq, lp);
1320
1321        spin_unlock_irqrestore(&lp->lock, flags);
1322
1323        return err;
1324}
1325EXPORT_SYMBOL(ldc_bind);
1326
1327int ldc_connect(struct ldc_channel *lp)
1328{
1329        unsigned long flags;
1330        int err;
1331
1332        if (lp->cfg.mode == LDC_MODE_RAW)
1333                return -EINVAL;
1334
1335        spin_lock_irqsave(&lp->lock, flags);
1336
1337        if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1338            !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1339            lp->hs_state != LDC_HS_OPEN)
1340                err = -EINVAL;
1341        else
1342                err = start_handshake(lp);
1343
1344        spin_unlock_irqrestore(&lp->lock, flags);
1345
1346        return err;
1347}
1348EXPORT_SYMBOL(ldc_connect);
1349
1350int ldc_disconnect(struct ldc_channel *lp)
1351{
1352        unsigned long hv_err, flags;
1353        int err;
1354
1355        if (lp->cfg.mode == LDC_MODE_RAW)
1356                return -EINVAL;
1357
1358        if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1359            !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1360                return -EINVAL;
1361
1362        spin_lock_irqsave(&lp->lock, flags);
1363
1364        err = -ENODEV;
1365        hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1366        if (hv_err)
1367                goto out_err;
1368
1369        hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1370        if (hv_err)
1371                goto out_err;
1372
1373        hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1374        if (hv_err)
1375                goto out_err;
1376
1377        hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1378        if (hv_err)
1379                goto out_err;
1380
1381        ldc_set_state(lp, LDC_STATE_BOUND);
1382        lp->hs_state = LDC_HS_OPEN;
1383        lp->flags |= LDC_FLAG_RESET;
1384
1385        spin_unlock_irqrestore(&lp->lock, flags);
1386
1387        return 0;
1388
1389out_err:
1390        sun4v_ldc_tx_qconf(lp->id, 0, 0);
1391        sun4v_ldc_rx_qconf(lp->id, 0, 0);
1392        free_irq(lp->cfg.tx_irq, lp);
1393        free_irq(lp->cfg.rx_irq, lp);
1394        lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1395                       LDC_FLAG_REGISTERED_QUEUES);
1396        ldc_set_state(lp, LDC_STATE_INIT);
1397
1398        spin_unlock_irqrestore(&lp->lock, flags);
1399
1400        return err;
1401}
1402EXPORT_SYMBOL(ldc_disconnect);
1403
1404int ldc_state(struct ldc_channel *lp)
1405{
1406        return lp->state;
1407}
1408EXPORT_SYMBOL(ldc_state);
1409
1410static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1411{
1412        struct ldc_packet *p;
1413        unsigned long new_tail;
1414        int err;
1415
1416        if (size > LDC_PACKET_SIZE)
1417                return -EMSGSIZE;
1418
1419        p = data_get_tx_packet(lp, &new_tail);
1420        if (!p)
1421                return -EAGAIN;
1422
1423        memcpy(p, buf, size);
1424
1425        err = send_tx_packet(lp, p, new_tail);
1426        if (!err)
1427                err = size;
1428
1429        return err;
1430}
1431
1432static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1433{
1434        struct ldc_packet *p;
1435        unsigned long hv_err, new;
1436        int err;
1437
1438        if (size < LDC_PACKET_SIZE)
1439                return -EINVAL;
1440
1441        hv_err = sun4v_ldc_rx_get_state(lp->id,
1442                                        &lp->rx_head,
1443                                        &lp->rx_tail,
1444                                        &lp->chan_state);
1445        if (hv_err)
1446                return ldc_abort(lp);
1447
1448        if (lp->chan_state == LDC_CHANNEL_DOWN ||
1449            lp->chan_state == LDC_CHANNEL_RESETTING)
1450                return -ECONNRESET;
1451
1452        if (lp->rx_head == lp->rx_tail)
1453                return 0;
1454
1455        p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1456        memcpy(buf, p, LDC_PACKET_SIZE);
1457
1458        new = rx_advance(lp, lp->rx_head);
1459        lp->rx_head = new;
1460
1461        err = __set_rx_head(lp, new);
1462        if (err < 0)
1463                err = -ECONNRESET;
1464        else
1465                err = LDC_PACKET_SIZE;
1466
1467        return err;
1468}
1469
1470static const struct ldc_mode_ops raw_ops = {
1471        .write          =       write_raw,
1472        .read           =       read_raw,
1473};
1474
1475static int write_nonraw(struct ldc_channel *lp, const void *buf,
1476                        unsigned int size)
1477{
1478        unsigned long hv_err, tail;
1479        unsigned int copied;
1480        u32 seq;
1481        int err;
1482
1483        hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1484                                        &lp->chan_state);
1485        if (unlikely(hv_err))
1486                return -EBUSY;
1487
1488        if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1489                return ldc_abort(lp);
1490
1491        if (!tx_has_space_for(lp, size))
1492                return -EAGAIN;
1493
1494        seq = lp->snd_nxt;
1495        copied = 0;
1496        tail = lp->tx_tail;
1497        while (copied < size) {
1498                struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1499                u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1500                            p->u.u_data :
1501                            p->u.r.r_data);
1502                int data_len;
1503
1504                p->type = LDC_DATA;
1505                p->stype = LDC_INFO;
1506                p->ctrl = 0;
1507
1508                data_len = size - copied;
1509                if (data_len > lp->mss)
1510                        data_len = lp->mss;
1511
1512                BUG_ON(data_len > LDC_LEN);
1513
1514                p->env = (data_len |
1515                          (copied == 0 ? LDC_START : 0) |
1516                          (data_len == size - copied ? LDC_STOP : 0));
1517
1518                p->seqid = ++seq;
1519
1520                ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1521                       p->type,
1522                       p->stype,
1523                       p->ctrl,
1524                       p->env,
1525                       p->seqid);
1526
1527                memcpy(data, buf, data_len);
1528                buf += data_len;
1529                copied += data_len;
1530
1531                tail = tx_advance(lp, tail);
1532        }
1533
1534        err = set_tx_tail(lp, tail);
1535        if (!err) {
1536                lp->snd_nxt = seq;
1537                err = size;
1538        }
1539
1540        return err;
1541}
1542
1543static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1544                      struct ldc_packet *first_frag)
1545{
1546        int err;
1547
1548        if (first_frag)
1549                lp->rcv_nxt = first_frag->seqid - 1;
1550
1551        err = send_data_nack(lp, p);
1552        if (err)
1553                return err;
1554
1555        err = __set_rx_head(lp, lp->rx_tail);
1556        if (err < 0)
1557                return ldc_abort(lp);
1558
1559        return 0;
1560}
1561
1562static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1563{
1564        if (p->stype & LDC_ACK) {
1565                int err = process_data_ack(lp, p);
1566                if (err)
1567                        return err;
1568        }
1569        if (p->stype & LDC_NACK)
1570                return ldc_abort(lp);
1571
1572        return 0;
1573}
1574
1575static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1576{
1577        unsigned long dummy;
1578        int limit = 1000;
1579
1580        ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1581               cur_head, lp->rx_head, lp->rx_tail);
1582        while (limit-- > 0) {
1583                unsigned long hv_err;
1584
1585                hv_err = sun4v_ldc_rx_get_state(lp->id,
1586                                                &dummy,
1587                                                &lp->rx_tail,
1588                                                &lp->chan_state);
1589                if (hv_err)
1590                        return ldc_abort(lp);
1591
1592                if (lp->chan_state == LDC_CHANNEL_DOWN ||
1593                    lp->chan_state == LDC_CHANNEL_RESETTING)
1594                        return -ECONNRESET;
1595
1596                if (cur_head != lp->rx_tail) {
1597                        ldcdbg(DATA, "DATA WAIT DONE "
1598                               "head[%lx] tail[%lx] chan_state[%lx]\n",
1599                               dummy, lp->rx_tail, lp->chan_state);
1600                        return 0;
1601                }
1602
1603                udelay(1);
1604        }
1605        return -EAGAIN;
1606}
1607
1608static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1609{
1610        int err = __set_rx_head(lp, head);
1611
1612        if (err < 0)
1613                return ldc_abort(lp);
1614
1615        lp->rx_head = head;
1616        return 0;
1617}
1618
1619static void send_data_ack(struct ldc_channel *lp)
1620{
1621        unsigned long new_tail;
1622        struct ldc_packet *p;
1623
1624        p = data_get_tx_packet(lp, &new_tail);
1625        if (likely(p)) {
1626                int err;
1627
1628                memset(p, 0, sizeof(*p));
1629                p->type = LDC_DATA;
1630                p->stype = LDC_ACK;
1631                p->ctrl = 0;
1632                p->seqid = lp->snd_nxt + 1;
1633                p->u.r.ackid = lp->rcv_nxt;
1634
1635                err = send_tx_packet(lp, p, new_tail);
1636                if (!err)
1637                        lp->snd_nxt++;
1638        }
1639}
1640
1641static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1642{
1643        struct ldc_packet *first_frag;
1644        unsigned long hv_err, new;
1645        int err, copied;
1646
1647        hv_err = sun4v_ldc_rx_get_state(lp->id,
1648                                        &lp->rx_head,
1649                                        &lp->rx_tail,
1650                                        &lp->chan_state);
1651        if (hv_err)
1652                return ldc_abort(lp);
1653
1654        if (lp->chan_state == LDC_CHANNEL_DOWN ||
1655            lp->chan_state == LDC_CHANNEL_RESETTING)
1656                return -ECONNRESET;
1657
1658        if (lp->rx_head == lp->rx_tail)
1659                return 0;
1660
1661        first_frag = NULL;
1662        copied = err = 0;
1663        new = lp->rx_head;
1664        while (1) {
1665                struct ldc_packet *p;
1666                int pkt_len;
1667
1668                BUG_ON(new == lp->rx_tail);
1669                p = lp->rx_base + (new / LDC_PACKET_SIZE);
1670
1671                ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1672                       "rcv_nxt[%08x]\n",
1673                       p->type,
1674                       p->stype,
1675                       p->ctrl,
1676                       p->env,
1677                       p->seqid,
1678                       p->u.r.ackid,
1679                       lp->rcv_nxt);
1680
1681                if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1682                        err = rx_bad_seq(lp, p, first_frag);
1683                        copied = 0;
1684                        break;
1685                }
1686
1687                if (p->type & LDC_CTRL) {
1688                        err = process_control_frame(lp, p);
1689                        if (err < 0)
1690                                break;
1691                        err = 0;
1692                }
1693
1694                lp->rcv_nxt = p->seqid;
1695
1696                if (!(p->type & LDC_DATA)) {
1697                        new = rx_advance(lp, new);
1698                        goto no_data;
1699                }
1700                if (p->stype & (LDC_ACK | LDC_NACK)) {
1701                        err = data_ack_nack(lp, p);
1702                        if (err)
1703                                break;
1704                }
1705                if (!(p->stype & LDC_INFO)) {
1706                        new = rx_advance(lp, new);
1707                        err = rx_set_head(lp, new);
1708                        if (err)
1709                                break;
1710                        goto no_data;
1711                }
1712
1713                pkt_len = p->env & LDC_LEN;
1714
1715                /* Every initial packet starts with the START bit set.
1716                 *
1717                 * Singleton packets will have both START+STOP set.
1718                 *
1719                 * Fragments will have START set in the first frame, STOP
1720                 * set in the last frame, and neither bit set in middle
1721                 * frames of the packet.
1722                 *
1723                 * Therefore if we are at the beginning of a packet and
1724                 * we don't see START, or we are in the middle of a fragmented
1725                 * packet and do see START, we are unsynchronized and should
1726                 * flush the RX queue.
1727                 */
1728                if ((first_frag == NULL && !(p->env & LDC_START)) ||
1729                    (first_frag != NULL &&  (p->env & LDC_START))) {
1730                        if (!first_frag)
1731                                new = rx_advance(lp, new);
1732
1733                        err = rx_set_head(lp, new);
1734                        if (err)
1735                                break;
1736
1737                        if (!first_frag)
1738                                goto no_data;
1739                }
1740                if (!first_frag)
1741                        first_frag = p;
1742
1743                if (pkt_len > size - copied) {
1744                        /* User didn't give us a big enough buffer,
1745                         * what to do?  This is a pretty serious error.
1746                         *
1747                         * Since we haven't updated the RX ring head to
1748                         * consume any of the packets, signal the error
1749                         * to the user and just leave the RX ring alone.
1750                         *
1751                         * This seems the best behavior because this allows
1752                         * a user of the LDC layer to start with a small
1753                         * RX buffer for ldc_read() calls and use -EMSGSIZE
1754                         * as a cue to enlarge it's read buffer.
1755                         */
1756                        err = -EMSGSIZE;
1757                        break;
1758                }
1759
1760                /* Ok, we are gonna eat this one.  */
1761                new = rx_advance(lp, new);
1762
1763                memcpy(buf,
1764                       (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1765                        p->u.u_data : p->u.r.r_data), pkt_len);
1766                buf += pkt_len;
1767                copied += pkt_len;
1768
1769                if (p->env & LDC_STOP)
1770                        break;
1771
1772no_data:
1773                if (new == lp->rx_tail) {
1774                        err = rx_data_wait(lp, new);
1775                        if (err)
1776                                break;
1777                }
1778        }
1779
1780        if (!err)
1781                err = rx_set_head(lp, new);
1782
1783        if (err && first_frag)
1784                lp->rcv_nxt = first_frag->seqid - 1;
1785
1786        if (!err) {
1787                err = copied;
1788                if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1789                        send_data_ack(lp);
1790        }
1791
1792        return err;
1793}
1794
1795static const struct ldc_mode_ops nonraw_ops = {
1796        .write          =       write_nonraw,
1797        .read           =       read_nonraw,
1798};
1799
1800static int write_stream(struct ldc_channel *lp, const void *buf,
1801                        unsigned int size)
1802{
1803        if (size > lp->cfg.mtu)
1804                size = lp->cfg.mtu;
1805        return write_nonraw(lp, buf, size);
1806}
1807
1808static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1809{
1810        if (!lp->mssbuf_len) {
1811                int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1812                if (err < 0)
1813                        return err;
1814
1815                lp->mssbuf_len = err;
1816                lp->mssbuf_off = 0;
1817        }
1818
1819        if (size > lp->mssbuf_len)
1820                size = lp->mssbuf_len;
1821        memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1822
1823        lp->mssbuf_off += size;
1824        lp->mssbuf_len -= size;
1825
1826        return size;
1827}
1828
1829static const struct ldc_mode_ops stream_ops = {
1830        .write          =       write_stream,
1831        .read           =       read_stream,
1832};
1833
1834int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1835{
1836        unsigned long flags;
1837        int err;
1838
1839        if (!buf)
1840                return -EINVAL;
1841
1842        if (!size)
1843                return 0;
1844
1845        spin_lock_irqsave(&lp->lock, flags);
1846
1847        if (lp->hs_state != LDC_HS_COMPLETE)
1848                err = -ENOTCONN;
1849        else
1850                err = lp->mops->write(lp, buf, size);
1851
1852        spin_unlock_irqrestore(&lp->lock, flags);
1853
1854        return err;
1855}
1856EXPORT_SYMBOL(ldc_write);
1857
1858int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1859{
1860        unsigned long flags;
1861        int err;
1862
1863        if (!buf)
1864                return -EINVAL;
1865
1866        if (!size)
1867                return 0;
1868
1869        spin_lock_irqsave(&lp->lock, flags);
1870
1871        if (lp->hs_state != LDC_HS_COMPLETE)
1872                err = -ENOTCONN;
1873        else
1874                err = lp->mops->read(lp, buf, size);
1875
1876        spin_unlock_irqrestore(&lp->lock, flags);
1877
1878        return err;
1879}
1880EXPORT_SYMBOL(ldc_read);
1881
1882static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1883{
1884        struct iommu_arena *arena = &iommu->arena;
1885        unsigned long n, start, end, limit;
1886        int pass;
1887
1888        limit = arena->limit;
1889        start = arena->hint;
1890        pass = 0;
1891
1892again:
1893        n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
1894        end = n + npages;
1895        if (unlikely(end >= limit)) {
1896                if (likely(pass < 1)) {
1897                        limit = start;
1898                        start = 0;
1899                        pass++;
1900                        goto again;
1901                } else {
1902                        /* Scanned the whole thing, give up. */
1903                        return -1;
1904                }
1905        }
1906        bitmap_set(arena->map, n, npages);
1907
1908        arena->hint = end;
1909
1910        return n;
1911}
1912
1913#define COOKIE_PGSZ_CODE        0xf000000000000000ULL
1914#define COOKIE_PGSZ_CODE_SHIFT  60ULL
1915
1916static u64 pagesize_code(void)
1917{
1918        switch (PAGE_SIZE) {
1919        default:
1920        case (8ULL * 1024ULL):
1921                return 0;
1922        case (64ULL * 1024ULL):
1923                return 1;
1924        case (512ULL * 1024ULL):
1925                return 2;
1926        case (4ULL * 1024ULL * 1024ULL):
1927                return 3;
1928        case (32ULL * 1024ULL * 1024ULL):
1929                return 4;
1930        case (256ULL * 1024ULL * 1024ULL):
1931                return 5;
1932        }
1933}
1934
1935static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1936{
1937        return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1938                (index << PAGE_SHIFT) |
1939                page_offset);
1940}
1941
1942static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1943{
1944        u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1945
1946        cookie &= ~COOKIE_PGSZ_CODE;
1947
1948        *shift = szcode * 3;
1949
1950        return (cookie >> (13ULL + (szcode * 3ULL)));
1951}
1952
1953static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1954                                             unsigned long npages)
1955{
1956        long entry;
1957
1958        entry = arena_alloc(iommu, npages);
1959        if (unlikely(entry < 0))
1960                return NULL;
1961
1962        return iommu->page_table + entry;
1963}
1964
1965static u64 perm_to_mte(unsigned int map_perm)
1966{
1967        u64 mte_base;
1968
1969        mte_base = pagesize_code();
1970
1971        if (map_perm & LDC_MAP_SHADOW) {
1972                if (map_perm & LDC_MAP_R)
1973                        mte_base |= LDC_MTE_COPY_R;
1974                if (map_perm & LDC_MAP_W)
1975                        mte_base |= LDC_MTE_COPY_W;
1976        }
1977        if (map_perm & LDC_MAP_DIRECT) {
1978                if (map_perm & LDC_MAP_R)
1979                        mte_base |= LDC_MTE_READ;
1980                if (map_perm & LDC_MAP_W)
1981                        mte_base |= LDC_MTE_WRITE;
1982                if (map_perm & LDC_MAP_X)
1983                        mte_base |= LDC_MTE_EXEC;
1984        }
1985        if (map_perm & LDC_MAP_IO) {
1986                if (map_perm & LDC_MAP_R)
1987                        mte_base |= LDC_MTE_IOMMU_R;
1988                if (map_perm & LDC_MAP_W)
1989                        mte_base |= LDC_MTE_IOMMU_W;
1990        }
1991
1992        return mte_base;
1993}
1994
1995static int pages_in_region(unsigned long base, long len)
1996{
1997        int count = 0;
1998
1999        do {
2000                unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
2001
2002                len -= (new - base);
2003                base = new;
2004                count++;
2005        } while (len > 0);
2006
2007        return count;
2008}
2009
2010struct cookie_state {
2011        struct ldc_mtable_entry         *page_table;
2012        struct ldc_trans_cookie         *cookies;
2013        u64                             mte_base;
2014        u64                             prev_cookie;
2015        u32                             pte_idx;
2016        u32                             nc;
2017};
2018
2019static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2020                         unsigned long off, unsigned long len)
2021{
2022        do {
2023                unsigned long tlen, new = pa + PAGE_SIZE;
2024                u64 this_cookie;
2025
2026                sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2027
2028                tlen = PAGE_SIZE;
2029                if (off)
2030                        tlen = PAGE_SIZE - off;
2031                if (tlen > len)
2032                        tlen = len;
2033
2034                this_cookie = make_cookie(sp->pte_idx,
2035                                          pagesize_code(), off);
2036
2037                off = 0;
2038
2039                if (this_cookie == sp->prev_cookie) {
2040                        sp->cookies[sp->nc - 1].cookie_size += tlen;
2041                } else {
2042                        sp->cookies[sp->nc].cookie_addr = this_cookie;
2043                        sp->cookies[sp->nc].cookie_size = tlen;
2044                        sp->nc++;
2045                }
2046                sp->prev_cookie = this_cookie + tlen;
2047
2048                sp->pte_idx++;
2049
2050                len -= tlen;
2051                pa = new;
2052        } while (len > 0);
2053}
2054
2055static int sg_count_one(struct scatterlist *sg)
2056{
2057        unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2058        long len = sg->length;
2059
2060        if ((sg->offset | len) & (8UL - 1))
2061                return -EFAULT;
2062
2063        return pages_in_region(base + sg->offset, len);
2064}
2065
2066static int sg_count_pages(struct scatterlist *sg, int num_sg)
2067{
2068        int count;
2069        int i;
2070
2071        count = 0;
2072        for (i = 0; i < num_sg; i++) {
2073                int err = sg_count_one(sg + i);
2074                if (err < 0)
2075                        return err;
2076                count += err;
2077        }
2078
2079        return count;
2080}
2081
2082int ldc_map_sg(struct ldc_channel *lp,
2083               struct scatterlist *sg, int num_sg,
2084               struct ldc_trans_cookie *cookies, int ncookies,
2085               unsigned int map_perm)
2086{
2087        unsigned long i, npages, flags;
2088        struct ldc_mtable_entry *base;
2089        struct cookie_state state;
2090        struct ldc_iommu *iommu;
2091        int err;
2092
2093        if (map_perm & ~LDC_MAP_ALL)
2094                return -EINVAL;
2095
2096        err = sg_count_pages(sg, num_sg);
2097        if (err < 0)
2098                return err;
2099
2100        npages = err;
2101        if (err > ncookies)
2102                return -EMSGSIZE;
2103
2104        iommu = &lp->iommu;
2105
2106        spin_lock_irqsave(&iommu->lock, flags);
2107        base = alloc_npages(iommu, npages);
2108        spin_unlock_irqrestore(&iommu->lock, flags);
2109
2110        if (!base)
2111                return -ENOMEM;
2112
2113        state.page_table = iommu->page_table;
2114        state.cookies = cookies;
2115        state.mte_base = perm_to_mte(map_perm);
2116        state.prev_cookie = ~(u64)0;
2117        state.pte_idx = (base - iommu->page_table);
2118        state.nc = 0;
2119
2120        for (i = 0; i < num_sg; i++)
2121                fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2122                             sg[i].offset, sg[i].length);
2123
2124        return state.nc;
2125}
2126EXPORT_SYMBOL(ldc_map_sg);
2127
2128int ldc_map_single(struct ldc_channel *lp,
2129                   void *buf, unsigned int len,
2130                   struct ldc_trans_cookie *cookies, int ncookies,
2131                   unsigned int map_perm)
2132{
2133        unsigned long npages, pa, flags;
2134        struct ldc_mtable_entry *base;
2135        struct cookie_state state;
2136        struct ldc_iommu *iommu;
2137
2138        if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2139                return -EINVAL;
2140
2141        pa = __pa(buf);
2142        if ((pa | len) & (8UL - 1))
2143                return -EFAULT;
2144
2145        npages = pages_in_region(pa, len);
2146
2147        iommu = &lp->iommu;
2148
2149        spin_lock_irqsave(&iommu->lock, flags);
2150        base = alloc_npages(iommu, npages);
2151        spin_unlock_irqrestore(&iommu->lock, flags);
2152
2153        if (!base)
2154                return -ENOMEM;
2155
2156        state.page_table = iommu->page_table;
2157        state.cookies = cookies;
2158        state.mte_base = perm_to_mte(map_perm);
2159        state.prev_cookie = ~(u64)0;
2160        state.pte_idx = (base - iommu->page_table);
2161        state.nc = 0;
2162        fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2163        BUG_ON(state.nc != 1);
2164
2165        return state.nc;
2166}
2167EXPORT_SYMBOL(ldc_map_single);
2168
2169static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2170                        u64 cookie, u64 size)
2171{
2172        struct iommu_arena *arena = &iommu->arena;
2173        unsigned long i, shift, index, npages;
2174        struct ldc_mtable_entry *base;
2175
2176        npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2177        index = cookie_to_index(cookie, &shift);
2178        base = iommu->page_table + index;
2179
2180        BUG_ON(index > arena->limit ||
2181               (index + npages) > arena->limit);
2182
2183        for (i = 0; i < npages; i++) {
2184                if (base->cookie)
2185                        sun4v_ldc_revoke(id, cookie + (i << shift),
2186                                         base->cookie);
2187                base->mte = 0;
2188                __clear_bit(index + i, arena->map);
2189        }
2190}
2191
2192void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2193               int ncookies)
2194{
2195        struct ldc_iommu *iommu = &lp->iommu;
2196        unsigned long flags;
2197        int i;
2198
2199        spin_lock_irqsave(&iommu->lock, flags);
2200        for (i = 0; i < ncookies; i++) {
2201                u64 addr = cookies[i].cookie_addr;
2202                u64 size = cookies[i].cookie_size;
2203
2204                free_npages(lp->id, iommu, addr, size);
2205        }
2206        spin_unlock_irqrestore(&iommu->lock, flags);
2207}
2208EXPORT_SYMBOL(ldc_unmap);
2209
2210int ldc_copy(struct ldc_channel *lp, int copy_dir,
2211             void *buf, unsigned int len, unsigned long offset,
2212             struct ldc_trans_cookie *cookies, int ncookies)
2213{
2214        unsigned int orig_len;
2215        unsigned long ra;
2216        int i;
2217
2218        if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2219                printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2220                       lp->id, copy_dir);
2221                return -EINVAL;
2222        }
2223
2224        ra = __pa(buf);
2225        if ((ra | len | offset) & (8UL - 1)) {
2226                printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2227                       "ra[%lx] len[%x] offset[%lx]\n",
2228                       lp->id, ra, len, offset);
2229                return -EFAULT;
2230        }
2231
2232        if (lp->hs_state != LDC_HS_COMPLETE ||
2233            (lp->flags & LDC_FLAG_RESET)) {
2234                printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2235                       "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2236                return -ECONNRESET;
2237        }
2238
2239        orig_len = len;
2240        for (i = 0; i < ncookies; i++) {
2241                unsigned long cookie_raddr = cookies[i].cookie_addr;
2242                unsigned long this_len = cookies[i].cookie_size;
2243                unsigned long actual_len;
2244
2245                if (unlikely(offset)) {
2246                        unsigned long this_off = offset;
2247
2248                        if (this_off > this_len)
2249                                this_off = this_len;
2250
2251                        offset -= this_off;
2252                        this_len -= this_off;
2253                        if (!this_len)
2254                                continue;
2255                        cookie_raddr += this_off;
2256                }
2257
2258                if (this_len > len)
2259                        this_len = len;
2260
2261                while (1) {
2262                        unsigned long hv_err;
2263
2264                        hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2265                                                cookie_raddr, ra,
2266                                                this_len, &actual_len);
2267                        if (unlikely(hv_err)) {
2268                                printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2269                                       "HV error %lu\n",
2270                                       lp->id, hv_err);
2271                                if (lp->hs_state != LDC_HS_COMPLETE ||
2272                                    (lp->flags & LDC_FLAG_RESET))
2273                                        return -ECONNRESET;
2274                                else
2275                                        return -EFAULT;
2276                        }
2277
2278                        cookie_raddr += actual_len;
2279                        ra += actual_len;
2280                        len -= actual_len;
2281                        if (actual_len == this_len)
2282                                break;
2283
2284                        this_len -= actual_len;
2285                }
2286
2287                if (!len)
2288                        break;
2289        }
2290
2291        /* It is caller policy what to do about short copies.
2292         * For example, a networking driver can declare the
2293         * packet a runt and drop it.
2294         */
2295
2296        return orig_len - len;
2297}
2298EXPORT_SYMBOL(ldc_copy);
2299
2300void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2301                          struct ldc_trans_cookie *cookies, int *ncookies,
2302                          unsigned int map_perm)
2303{
2304        void *buf;
2305        int err;
2306
2307        if (len & (8UL - 1))
2308                return ERR_PTR(-EINVAL);
2309
2310        buf = kzalloc(len, GFP_KERNEL);
2311        if (!buf)
2312                return ERR_PTR(-ENOMEM);
2313
2314        err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2315        if (err < 0) {
2316                kfree(buf);
2317                return ERR_PTR(err);
2318        }
2319        *ncookies = err;
2320
2321        return buf;
2322}
2323EXPORT_SYMBOL(ldc_alloc_exp_dring);
2324
2325void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2326                        struct ldc_trans_cookie *cookies, int ncookies)
2327{
2328        ldc_unmap(lp, cookies, ncookies);
2329        kfree(buf);
2330}
2331EXPORT_SYMBOL(ldc_free_exp_dring);
2332
2333static int __init ldc_init(void)
2334{
2335        unsigned long major, minor;
2336        struct mdesc_handle *hp;
2337        const u64 *v;
2338        int err;
2339        u64 mp;
2340
2341        hp = mdesc_grab();
2342        if (!hp)
2343                return -ENODEV;
2344
2345        mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2346        err = -ENODEV;
2347        if (mp == MDESC_NODE_NULL)
2348                goto out;
2349
2350        v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2351        if (!v)
2352                goto out;
2353
2354        major = 1;
2355        minor = 0;
2356        if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2357                printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2358                goto out;
2359        }
2360
2361        printk(KERN_INFO "%s", version);
2362
2363        if (!*v) {
2364                printk(KERN_INFO PFX "Domaining disabled.\n");
2365                goto out;
2366        }
2367        ldom_domaining_enabled = 1;
2368        err = 0;
2369
2370out:
2371        mdesc_release(hp);
2372        return err;
2373}
2374
2375core_initcall(ldc_init);
2376