drivers/rpmsg/qcom_glink_native.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016-2017, Linaro Ltd
   4  */
   5
   6 #include <linux/idr.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/list.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/of_address.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regmap.h>
  16 #include <linux/rpmsg.h>
  17 #include <linux/sizes.h>
  18 #include <linux/slab.h>
  19 #include <linux/wait.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/mailbox_client.h>
  22
  23 #include "rpmsg_internal.h"
  24 #include "qcom_glink_native.h"
  25
  26 #define GLINK_NAME_SIZE         32
  27 #define GLINK_VERSION_1         1
  28
  29 #define RPM_GLINK_CID_MIN       1
  30 #define RPM_GLINK_CID_MAX       65536
  31
  32 struct glink_msg {
  33         __le16 cmd;
  34         __le16 param1;
  35         __le32 param2;
  36         u8 data[];
  37 } __packed;
  38
  39 /**
  40  * struct glink_defer_cmd - deferred incoming control message
  41  * @node:       list node
  42  * @msg:        message header
  43  * @data:       payload of the message
  44  *
  45  * Copy of a received control message, to be added to @rx_queue and processed
  46  * by @rx_work of @qcom_glink.
  47  */
  48 struct glink_defer_cmd {
  49         struct list_head node;
  50
  51         struct glink_msg msg;
  52         u8 data[];
  53 };
  54
  55 /**
  56  * struct glink_core_rx_intent - RX intent
  57  * RX intent
  58  *
  59  * @data: pointer to the data (may be NULL for zero-copy)
  60  * @id: remote or local intent ID
  61  * @size: size of the original intent (do not modify)
  62  * @reuse: To mark if the intent can be reused after first use
  63  * @in_use: To mark if intent is already in use for the channel
  64  * @offset: next write offset (initially 0)
  65  * @node:       list node
  66  */
  67 struct glink_core_rx_intent {
  68         void *data;
  69         u32 id;
  70         size_t size;
  71         bool reuse;
  72         bool in_use;
  73         u32 offset;
  74
  75         struct list_head node;
  76 };
  77
  78 /**
  79  * struct qcom_glink - driver context, relates to one remote subsystem
  80  * @dev:        reference to the associated struct device
  81  * @rx_pipe:    pipe object for receive FIFO
  82  * @tx_pipe:    pipe object for transmit FIFO
  83  * @rx_work:    worker for handling received control messages
  84  * @rx_lock:    protects the @rx_queue
  85  * @rx_queue:   queue of received control messages to be processed in @rx_work
  86  * @tx_lock:    synchronizes operations on the tx fifo
  87  * @idr_lock:   synchronizes @lcids and @rcids modifications
  88  * @lcids:      idr of all channels with a known local channel id
  89  * @rcids:      idr of all channels with a known remote channel id
  90  * @features:   remote features
  91  * @intentless: flag to indicate that there is no intent
  92  * @tx_avail_notify: Waitqueue for pending tx tasks
  93  * @sent_read_notify: flag to check cmd sent or not
  94  * @abort_tx:   flag indicating that all tx attempts should fail
  95  */
  96 struct qcom_glink {
  97         struct device *dev;
  98
  99         struct qcom_glink_pipe *rx_pipe;
 100         struct qcom_glink_pipe *tx_pipe;
 101
 102         struct work_struct rx_work;
 103         spinlock_t rx_lock;
 104         struct list_head rx_queue;
 105
 106         spinlock_t tx_lock;
 107
 108         spinlock_t idr_lock;
 109         struct idr lcids;
 110         struct idr rcids;
 111         unsigned long features;
 112
 113         bool intentless;
 114         wait_queue_head_t tx_avail_notify;
 115         bool sent_read_notify;
 116
 117         bool abort_tx;
 118 };
 119
 120 enum {
 121         GLINK_STATE_CLOSED,
 122         GLINK_STATE_OPENING,
 123         GLINK_STATE_OPEN,
 124         GLINK_STATE_CLOSING,
 125 };
 126
 127 /**
 128  * struct glink_channel - internal representation of a channel
 129  * @rpdev:      rpdev reference, only used for primary endpoints
 130  * @ept:        rpmsg endpoint this channel is associated with
 131  * @glink:      qcom_glink context handle
 132  * @refcount:   refcount for the channel object
 133  * @recv_lock:  guard for @ept.cb
 134  * @name:       unique channel name/identifier
 135  * @lcid:       channel id, in local space
 136  * @rcid:       channel id, in remote space
 137  * @intent_lock: lock for protection of @liids, @riids
 138  * @liids:      idr of all local intents
 139  * @riids:      idr of all remote intents
 140  * @intent_work: worker responsible for transmitting rx_done packets
 141  * @done_intents: list of intents that needs to be announced rx_done
 142  * @buf:        receive buffer, for gathering fragments
 143  * @buf_offset: write offset in @buf
 144  * @buf_size:   size of current @buf
 145  * @open_ack:   completed once remote has acked the open-request
 146  * @open_req:   completed once open-request has been received
 147  * @intent_req_lock: Synchronises multiple intent requests
 148  * @intent_req_result: Result of intent request
 149  * @intent_received: flag indicating that an intent has been received
 150  * @intent_req_wq: wait queue for intent_req signalling
 151  */
 152 struct glink_channel {
 153         struct rpmsg_endpoint ept;
 154
 155         struct rpmsg_device *rpdev;
 156         struct qcom_glink *glink;
 157
 158         struct kref refcount;
 159
 160         spinlock_t recv_lock;
 161
 162         char *name;
 163         unsigned int lcid;
 164         unsigned int rcid;
 165
 166         spinlock_t intent_lock;
 167         struct idr liids;
 168         struct idr riids;
 169         struct work_struct intent_work;
 170         struct list_head done_intents;
 171
 172         struct glink_core_rx_intent *buf;
 173         int buf_offset;
 174         int buf_size;
 175
 176         struct completion open_ack;
 177         struct completion open_req;
 178
 179         struct mutex intent_req_lock;
 180         int intent_req_result;
 181         bool intent_received;
 182         wait_queue_head_t intent_req_wq;
 183 };
 184
 185 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 186
 187 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 188
 189 #define GLINK_CMD_VERSION               0
 190 #define GLINK_CMD_VERSION_ACK           1
 191 #define GLINK_CMD_OPEN                  2
 192 #define GLINK_CMD_CLOSE                 3
 193 #define GLINK_CMD_OPEN_ACK              4
 194 #define GLINK_CMD_INTENT                5
 195 #define GLINK_CMD_RX_DONE               6
 196 #define GLINK_CMD_RX_INTENT_REQ         7
 197 #define GLINK_CMD_RX_INTENT_REQ_ACK     8
 198 #define GLINK_CMD_TX_DATA               9
 199 #define GLINK_CMD_CLOSE_ACK             11
 200 #define GLINK_CMD_TX_DATA_CONT          12
 201 #define GLINK_CMD_READ_NOTIF            13
 202 #define GLINK_CMD_RX_DONE_W_REUSE       14
 203 #define GLINK_CMD_SIGNALS               15
 204
 205 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 206
 207 #define NATIVE_DTR_SIG                  NATIVE_DSR_SIG
 208 #define NATIVE_DSR_SIG                  BIT(31)
 209 #define NATIVE_RTS_SIG                  NATIVE_CTS_SIG
 210 #define NATIVE_CTS_SIG                  BIT(30)
 211
 212 static void qcom_glink_rx_done_work(struct work_struct *work);
 213
 214 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 215                                                       const char *name)
 216 {
 217         struct glink_channel *channel;
 218
 219         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 220         if (!channel)
 221                 return ERR_PTR(-ENOMEM);
 222
 223         /* Setup glink internal glink_channel data */
 224         spin_lock_init(&channel->recv_lock);
 225         spin_lock_init(&channel->intent_lock);
 226         mutex_init(&channel->intent_req_lock);
 227
 228         channel->glink = glink;
 229         channel->name = kstrdup(name, GFP_KERNEL);
 230
 231         init_completion(&channel->open_req);
 232         init_completion(&channel->open_ack);
 233         init_waitqueue_head(&channel->intent_req_wq);
 234
 235         INIT_LIST_HEAD(&channel->done_intents);
 236         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 237
 238         idr_init(&channel->liids);
 239         idr_init(&channel->riids);
 240         kref_init(&channel->refcount);
 241
 242         return channel;
 243 }
 244
 245 static void qcom_glink_channel_release(struct kref *ref)
 246 {
 247         struct glink_channel *channel = container_of(ref, struct glink_channel,
 248                                                      refcount);
 249         struct glink_core_rx_intent *intent;
 250         struct glink_core_rx_intent *tmp;
 251         unsigned long flags;
 252         int iid;
 253
 254         /* cancel pending rx_done work */
 255         cancel_work_sync(&channel->intent_work);
 256
 257         spin_lock_irqsave(&channel->intent_lock, flags);
 258         /* Free all non-reuse intents pending rx_done work */
 259         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 260                 if (!intent->reuse) {
 261                         kfree(intent->data);
 262                         kfree(intent);
 263                 }
 264         }
 265
 266         idr_for_each_entry(&channel->liids, tmp, iid) {
 267                 kfree(tmp->data);
 268                 kfree(tmp);
 269         }
 270         idr_destroy(&channel->liids);
 271
 272         idr_for_each_entry(&channel->riids, tmp, iid)
 273                 kfree(tmp);
 274         idr_destroy(&channel->riids);
 275         spin_unlock_irqrestore(&channel->intent_lock, flags);
 276
 277         kfree(channel->name);
 278         kfree(channel);
 279 }
 280
 281 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 282 {
 283         return glink->rx_pipe->avail(glink->rx_pipe);
 284 }
 285
 286 static void qcom_glink_rx_peek(struct qcom_glink *glink,
 287                                void *data, unsigned int offset, size_t count)
 288 {
 289         glink->rx_pipe->peek(glink->rx_pipe, data, offset, count);
 290 }
 291
 292 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 293 {
 294         glink->rx_pipe->advance(glink->rx_pipe, count);
 295 }
 296
 297 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 298 {
 299         return glink->tx_pipe->avail(glink->tx_pipe);
 300 }
 301
 302 static void qcom_glink_tx_write(struct qcom_glink *glink,
 303                                 const void *hdr, size_t hlen,
 304                                 const void *data, size_t dlen)
 305 {
 306         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 307 }
 308
 309 static void qcom_glink_tx_kick(struct qcom_glink *glink)
 310 {
 311         glink->tx_pipe->kick(glink->tx_pipe);
 312 }
 313
 314 static void qcom_glink_send_read_notify(struct qcom_glink *glink)
 315 {
 316         struct glink_msg msg;
 317
 318         msg.cmd = cpu_to_le16(GLINK_CMD_READ_NOTIF);
 319         msg.param1 = 0;
 320         msg.param2 = 0;
 321
 322         qcom_glink_tx_write(glink, &msg, sizeof(msg), NULL, 0);
 323
 324         qcom_glink_tx_kick(glink);
 325 }
 326
 327 static int qcom_glink_tx(struct qcom_glink *glink,
 328                          const void *hdr, size_t hlen,
 329                          const void *data, size_t dlen, bool wait)
 330 {
 331         unsigned int tlen = hlen + dlen;
 332         unsigned long flags;
 333         int ret = 0;
 334
 335         /* Reject packets that are too big */
 336         if (tlen >= glink->tx_pipe->length)
 337                 return -EINVAL;
 338
 339         spin_lock_irqsave(&glink->tx_lock, flags);
 340
 341         if (glink->abort_tx) {
 342                 ret = -EIO;
 343                 goto out;
 344         }
 345
 346         while (qcom_glink_tx_avail(glink) < tlen) {
 347                 if (!wait) {
 348                         ret = -EAGAIN;
 349                         goto out;
 350                 }
 351
 352                 if (glink->abort_tx) {
 353                         ret = -EIO;
 354                         goto out;
 355                 }
 356
 357                 if (!glink->sent_read_notify) {
 358                         glink->sent_read_notify = true;
 359                         qcom_glink_send_read_notify(glink);
 360                 }
 361
 362                 /* Wait without holding the tx_lock */
 363                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 364
 365                 wait_event_timeout(glink->tx_avail_notify,
 366                                    qcom_glink_tx_avail(glink) >= tlen, 10 * HZ);
 367
 368                 spin_lock_irqsave(&glink->tx_lock, flags);
 369
 370                 if (qcom_glink_tx_avail(glink) >= tlen)
 371                         glink->sent_read_notify = false;
 372         }
 373
 374         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 375         qcom_glink_tx_kick(glink);
 376
 377 out:
 378         spin_unlock_irqrestore(&glink->tx_lock, flags);
 379
 380         return ret;
 381 }
 382
 383 static int qcom_glink_send_version(struct qcom_glink *glink)
 384 {
 385         struct glink_msg msg;
 386
 387         msg.cmd = cpu_to_le16(GLINK_CMD_VERSION);
 388         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 389         msg.param2 = cpu_to_le32(glink->features);
 390
 391         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 392 }
 393
 394 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 395 {
 396         struct glink_msg msg;
 397
 398         msg.cmd = cpu_to_le16(GLINK_CMD_VERSION_ACK);
 399         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 400         msg.param2 = cpu_to_le32(glink->features);
 401
 402         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 403 }
 404
 405 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 406                                      struct glink_channel *channel)
 407 {
 408         struct glink_msg msg;
 409
 410         msg.cmd = cpu_to_le16(GLINK_CMD_OPEN_ACK);
 411         msg.param1 = cpu_to_le16(channel->rcid);
 412         msg.param2 = cpu_to_le32(0);
 413
 414         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 415 }
 416
 417 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 418                                              unsigned int cid, bool granted)
 419 {
 420         struct glink_channel *channel;
 421         unsigned long flags;
 422
 423         spin_lock_irqsave(&glink->idr_lock, flags);
 424         channel = idr_find(&glink->rcids, cid);
 425         spin_unlock_irqrestore(&glink->idr_lock, flags);
 426         if (!channel) {
 427                 dev_err(glink->dev, "unable to find channel\n");
 428                 return;
 429         }
 430
 431         WRITE_ONCE(channel->intent_req_result, granted);
 432         wake_up_all(&channel->intent_req_wq);
 433 }
 434
 435 static void qcom_glink_intent_req_abort(struct glink_channel *channel)
 436 {
 437         WRITE_ONCE(channel->intent_req_result, 0);
 438         wake_up_all(&channel->intent_req_wq);
 439 }
 440
 441 /**
 442  * qcom_glink_send_open_req() - send a GLINK_CMD_OPEN request to the remote
 443  * @glink: Ptr to the glink edge
 444  * @channel: Ptr to the channel that the open req is sent
 445  *
 446  * Allocates a local channel id and sends a GLINK_CMD_OPEN message to the remote.
 447  * Will return with refcount held, regardless of outcome.
 448  *
 449  * Return: 0 on success, negative errno otherwise.
 450  */
 451 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 452                                     struct glink_channel *channel)
 453 {
 454         struct {
 455                 struct glink_msg msg;
 456                 u8 name[GLINK_NAME_SIZE];
 457         } __packed req;
 458         int name_len = strlen(channel->name) + 1;
 459         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 460         int ret;
 461         unsigned long flags;
 462
 463         kref_get(&channel->refcount);
 464
 465         spin_lock_irqsave(&glink->idr_lock, flags);
 466         ret = idr_alloc_cyclic(&glink->lcids, channel,
 467                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 468                                GFP_ATOMIC);
 469         spin_unlock_irqrestore(&glink->idr_lock, flags);
 470         if (ret < 0)
 471                 return ret;
 472
 473         channel->lcid = ret;
 474
 475         req.msg.cmd = cpu_to_le16(GLINK_CMD_OPEN);
 476         req.msg.param1 = cpu_to_le16(channel->lcid);
 477         req.msg.param2 = cpu_to_le32(name_len);
 478         strcpy(req.name, channel->name);
 479
 480         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 481         if (ret)
 482                 goto remove_idr;
 483
 484         return 0;
 485
 486 remove_idr:
 487         spin_lock_irqsave(&glink->idr_lock, flags);
 488         idr_remove(&glink->lcids, channel->lcid);
 489         channel->lcid = 0;
 490         spin_unlock_irqrestore(&glink->idr_lock, flags);
 491
 492         return ret;
 493 }
 494
 495 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 496                                       struct glink_channel *channel)
 497 {
 498         struct glink_msg req;
 499
 500         req.cmd = cpu_to_le16(GLINK_CMD_CLOSE);
 501         req.param1 = cpu_to_le16(channel->lcid);
 502         req.param2 = 0;
 503
 504         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 505 }
 506
 507 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 508                                       unsigned int rcid)
 509 {
 510         struct glink_msg req;
 511
 512         req.cmd = cpu_to_le16(GLINK_CMD_CLOSE_ACK);
 513         req.param1 = cpu_to_le16(rcid);
 514         req.param2 = 0;
 515
 516         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 517 }
 518
 519 static void qcom_glink_rx_done_work(struct work_struct *work)
 520 {
 521         struct glink_channel *channel = container_of(work, struct glink_channel,
 522                                                      intent_work);
 523         struct qcom_glink *glink = channel->glink;
 524         struct glink_core_rx_intent *intent, *tmp;
 525         struct {
 526                 u16 id;
 527                 u16 lcid;
 528                 u32 liid;
 529         } __packed cmd;
 530
 531         unsigned int cid = channel->lcid;
 532         unsigned int iid;
 533         bool reuse;
 534         unsigned long flags;
 535
 536         spin_lock_irqsave(&channel->intent_lock, flags);
 537         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 538                 list_del(&intent->node);
 539                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 540                 iid = intent->id;
 541                 reuse = intent->reuse;
 542
 543                 cmd.id = reuse ? GLINK_CMD_RX_DONE_W_REUSE : GLINK_CMD_RX_DONE;
 544                 cmd.lcid = cid;
 545                 cmd.liid = iid;
 546
 547                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 548                 if (!reuse) {
 549                         kfree(intent->data);
 550                         kfree(intent);
 551                 }
 552                 spin_lock_irqsave(&channel->intent_lock, flags);
 553         }
 554         spin_unlock_irqrestore(&channel->intent_lock, flags);
 555 }
 556
 557 static void qcom_glink_rx_done(struct qcom_glink *glink,
 558                                struct glink_channel *channel,
 559                                struct glink_core_rx_intent *intent)
 560 {
 561         /* We don't send RX_DONE to intentless systems */
 562         if (glink->intentless) {
 563                 kfree(intent->data);
 564                 kfree(intent);
 565                 return;
 566         }
 567
 568         /* Take it off the tree of receive intents */
 569         if (!intent->reuse) {
 570                 spin_lock(&channel->intent_lock);
 571                 idr_remove(&channel->liids, intent->id);
 572                 spin_unlock(&channel->intent_lock);
 573         }
 574
 575         /* Schedule the sending of a rx_done indication */
 576         spin_lock(&channel->intent_lock);
 577         list_add_tail(&intent->node, &channel->done_intents);
 578         spin_unlock(&channel->intent_lock);
 579
 580         schedule_work(&channel->intent_work);
 581 }
 582
 583 /**
 584  * qcom_glink_receive_version() - receive version/features from remote system
 585  *
 586  * @glink:      pointer to transport interface
 587  * @version:    remote version
 588  * @features:   remote features
 589  *
 590  * This function is called in response to a remote-initiated version/feature
 591  * negotiation sequence.
 592  */
 593 static void qcom_glink_receive_version(struct qcom_glink *glink,
 594                                        u32 version,
 595                                        u32 features)
 596 {
 597         switch (version) {
 598         case 0:
 599                 break;
 600         case GLINK_VERSION_1:
 601                 glink->features &= features;
 602                 fallthrough;
 603         default:
 604                 qcom_glink_send_version_ack(glink);
 605                 break;
 606         }
 607 }
 608
 609 /**
 610  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 611  *
 612  * @glink:      pointer to transport interface
 613  * @version:    remote version response
 614  * @features:   remote features response
 615  *
 616  * This function is called in response to a local-initiated version/feature
 617  * negotiation sequence and is the counter-offer from the remote side based
 618  * upon the initial version and feature set requested.
 619  */
 620 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 621                                            u32 version,
 622                                            u32 features)
 623 {
 624         switch (version) {
 625         case 0:
 626                 /* Version negotiation failed */
 627                 break;
 628         case GLINK_VERSION_1:
 629                 if (features == glink->features)
 630                         break;
 631
 632                 glink->features &= features;
 633                 fallthrough;
 634         default:
 635                 qcom_glink_send_version(glink);
 636                 break;
 637         }
 638 }
 639
 640 /**
 641  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 642  *      wire format and transmit
 643  * @glink:      The transport to transmit on.
 644  * @channel:    The glink channel
 645  * @granted:    The request response to encode.
 646  *
 647  * Return: 0 on success or standard Linux error code.
 648  */
 649 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 650                                           struct glink_channel *channel,
 651                                           bool granted)
 652 {
 653         struct glink_msg msg;
 654
 655         msg.cmd = cpu_to_le16(GLINK_CMD_RX_INTENT_REQ_ACK);
 656         msg.param1 = cpu_to_le16(channel->lcid);
 657         msg.param2 = cpu_to_le32(granted);
 658
 659         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 660
 661         return 0;
 662 }
 663
 664 /**
 665  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 666  *                         transmit
 667  * @glink:      The transport to transmit on.
 668  * @channel:    The local channel
 669  * @intent:     The intent to pass on to remote.
 670  *
 671  * Return: 0 on success or standard Linux error code.
 672  */
 673 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 674                                        struct glink_channel *channel,
 675                                        struct glink_core_rx_intent *intent)
 676 {
 677         struct command {
 678                 __le16 id;
 679                 __le16 lcid;
 680                 __le32 count;
 681                 __le32 size;
 682                 __le32 liid;
 683         } __packed;
 684         struct command cmd;
 685
 686         cmd.id = cpu_to_le16(GLINK_CMD_INTENT);
 687         cmd.lcid = cpu_to_le16(channel->lcid);
 688         cmd.count = cpu_to_le32(1);
 689         cmd.size = cpu_to_le32(intent->size);
 690         cmd.liid = cpu_to_le32(intent->id);
 691
 692         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 693
 694         return 0;
 695 }
 696
 697 static struct glink_core_rx_intent *
 698 qcom_glink_alloc_intent(struct qcom_glink *glink,
 699                         struct glink_channel *channel,
 700                         size_t size,
 701                         bool reuseable)
 702 {
 703         struct glink_core_rx_intent *intent;
 704         int ret;
 705         unsigned long flags;
 706
 707         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 708         if (!intent)
 709                 return NULL;
 710
 711         intent->data = kzalloc(size, GFP_KERNEL);
 712         if (!intent->data)
 713                 goto free_intent;
 714
 715         spin_lock_irqsave(&channel->intent_lock, flags);
 716         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 717         if (ret < 0) {
 718                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 719                 goto free_data;
 720         }
 721         spin_unlock_irqrestore(&channel->intent_lock, flags);
 722
 723         intent->id = ret;
 724         intent->size = size;
 725         intent->reuse = reuseable;
 726
 727         return intent;
 728
 729 free_data:
 730         kfree(intent->data);
 731 free_intent:
 732         kfree(intent);
 733         return NULL;
 734 }
 735
 736 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 737                                       u32 cid, uint32_t iid,
 738                                       bool reuse)
 739 {
 740         struct glink_core_rx_intent *intent;
 741         struct glink_channel *channel;
 742         unsigned long flags;
 743
 744         spin_lock_irqsave(&glink->idr_lock, flags);
 745         channel = idr_find(&glink->rcids, cid);
 746         spin_unlock_irqrestore(&glink->idr_lock, flags);
 747         if (!channel) {
 748                 dev_err(glink->dev, "invalid channel id received\n");
 749                 return;
 750         }
 751
 752         spin_lock_irqsave(&channel->intent_lock, flags);
 753         intent = idr_find(&channel->riids, iid);
 754
 755         if (!intent) {
 756                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 757                 dev_err(glink->dev, "invalid intent id received\n");
 758                 return;
 759         }
 760
 761         intent->in_use = false;
 762
 763         if (!reuse) {
 764                 idr_remove(&channel->riids, intent->id);
 765                 kfree(intent);
 766         }
 767         spin_unlock_irqrestore(&channel->intent_lock, flags);
 768
 769         if (reuse) {
 770                 WRITE_ONCE(channel->intent_received, true);
 771                 wake_up_all(&channel->intent_req_wq);
 772         }
 773 }
 774
 775 /**
 776  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 777  *                                          from remote side
 778  * @glink:      Pointer to the transport interface
 779  * @cid:        Remote channel ID
 780  * @size:       size of the intent
 781  *
 782  * The function searches for the local channel to which the request for
 783  * rx_intent has arrived and allocates and notifies the remote back
 784  */
 785 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 786                                          u32 cid, size_t size)
 787 {
 788         struct glink_core_rx_intent *intent;
 789         struct glink_channel *channel;
 790         unsigned long flags;
 791
 792         spin_lock_irqsave(&glink->idr_lock, flags);
 793         channel = idr_find(&glink->rcids, cid);
 794         spin_unlock_irqrestore(&glink->idr_lock, flags);
 795
 796         if (!channel) {
 797                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 798                 return;
 799         }
 800
 801         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 802         if (intent)
 803                 qcom_glink_advertise_intent(glink, channel, intent);
 804
 805         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 806 }
 807
 808 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 809 {
 810         struct glink_defer_cmd *dcmd;
 811
 812         extra = ALIGN(extra, 8);
 813
 814         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 815                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 816                 return -ENXIO;
 817         }
 818
 819         dcmd = kzalloc(struct_size(dcmd, data, extra), GFP_ATOMIC);
 820         if (!dcmd)
 821                 return -ENOMEM;
 822
 823         INIT_LIST_HEAD(&dcmd->node);
 824
 825         qcom_glink_rx_peek(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 826
 827         spin_lock(&glink->rx_lock);
 828         list_add_tail(&dcmd->node, &glink->rx_queue);
 829         spin_unlock(&glink->rx_lock);
 830
 831         schedule_work(&glink->rx_work);
 832         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 833
 834         return 0;
 835 }
 836
 837 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 838 {
 839         struct glink_core_rx_intent *intent;
 840         struct glink_channel *channel;
 841         struct {
 842                 struct glink_msg msg;
 843                 __le32 chunk_size;
 844                 __le32 left_size;
 845         } __packed hdr;
 846         unsigned int chunk_size;
 847         unsigned int left_size;
 848         unsigned int rcid;
 849         unsigned int liid;
 850         int ret = 0;
 851         unsigned long flags;
 852
 853         if (avail < sizeof(hdr)) {
 854                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 855                 return -EAGAIN;
 856         }
 857
 858         qcom_glink_rx_peek(glink, &hdr, 0, sizeof(hdr));
 859         chunk_size = le32_to_cpu(hdr.chunk_size);
 860         left_size = le32_to_cpu(hdr.left_size);
 861
 862         if (avail < sizeof(hdr) + chunk_size) {
 863                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 864                 return -EAGAIN;
 865         }
 866
 867         rcid = le16_to_cpu(hdr.msg.param1);
 868         spin_lock_irqsave(&glink->idr_lock, flags);
 869         channel = idr_find(&glink->rcids, rcid);
 870         spin_unlock_irqrestore(&glink->idr_lock, flags);
 871         if (!channel) {
 872                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 873
 874                 /* Drop the message */
 875                 goto advance_rx;
 876         }
 877
 878         if (glink->intentless) {
 879                 /* Might have an ongoing, fragmented, message to append */
 880                 if (!channel->buf) {
 881                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 882                         if (!intent)
 883                                 return -ENOMEM;
 884
 885                         intent->data = kmalloc(chunk_size + left_size,
 886                                                GFP_ATOMIC);
 887                         if (!intent->data) {
 888                                 kfree(intent);
 889                                 return -ENOMEM;
 890                         }
 891
 892                         intent->id = 0xbabababa;
 893                         intent->size = chunk_size + left_size;
 894                         intent->offset = 0;
 895
 896                         channel->buf = intent;
 897                 } else {
 898                         intent = channel->buf;
 899                 }
 900         } else {
 901                 liid = le32_to_cpu(hdr.msg.param2);
 902
 903                 spin_lock_irqsave(&channel->intent_lock, flags);
 904                 intent = idr_find(&channel->liids, liid);
 905                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 906
 907                 if (!intent) {
 908                         dev_err(glink->dev,
 909                                 "no intent found for channel %s intent %d",
 910                                 channel->name, liid);
 911                         ret = -ENOENT;
 912                         goto advance_rx;
 913                 }
 914         }
 915
 916         if (intent->size - intent->offset < chunk_size) {
 917                 dev_err(glink->dev, "Insufficient space in intent\n");
 918
 919                 /* The packet header lied, drop payload */
 920                 goto advance_rx;
 921         }
 922
 923         qcom_glink_rx_peek(glink, intent->data + intent->offset,
 924                            sizeof(hdr), chunk_size);
 925         intent->offset += chunk_size;
 926
 927         /* Handle message when no fragments remain to be received */
 928         if (!left_size) {
 929                 spin_lock(&channel->recv_lock);
 930                 if (channel->ept.cb) {
 931                         channel->ept.cb(channel->ept.rpdev,
 932                                         intent->data,
 933                                         intent->offset,
 934                                         channel->ept.priv,
 935                                         RPMSG_ADDR_ANY);
 936                 }
 937                 spin_unlock(&channel->recv_lock);
 938
 939                 intent->offset = 0;
 940                 channel->buf = NULL;
 941
 942                 qcom_glink_rx_done(glink, channel, intent);
 943         }
 944
 945 advance_rx:
 946         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 947
 948         return ret;
 949 }
 950
 951 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 952                                      unsigned int cid,
 953                                      unsigned int count,
 954                                      size_t avail)
 955 {
 956         struct glink_core_rx_intent *intent;
 957         struct glink_channel *channel;
 958         struct intent_pair {
 959                 __le32 size;
 960                 __le32 iid;
 961         };
 962
 963         struct {
 964                 struct glink_msg msg;
 965                 struct intent_pair intents[];
 966         } __packed * msg;
 967
 968         const size_t msglen = struct_size(msg, intents, count);
 969         int ret;
 970         int i;
 971         unsigned long flags;
 972
 973         if (avail < msglen) {
 974                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 975                 return;
 976         }
 977
 978         spin_lock_irqsave(&glink->idr_lock, flags);
 979         channel = idr_find(&glink->rcids, cid);
 980         spin_unlock_irqrestore(&glink->idr_lock, flags);
 981         if (!channel) {
 982                 dev_err(glink->dev, "intents for non-existing channel\n");
 983                 qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 984                 return;
 985         }
 986
 987         msg = kmalloc(msglen, GFP_ATOMIC);
 988         if (!msg)
 989                 return;
 990
 991         qcom_glink_rx_peek(glink, msg, 0, msglen);
 992
 993         for (i = 0; i < count; ++i) {
 994                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 995                 if (!intent)
 996                         break;
 997
 998                 intent->id = le32_to_cpu(msg->intents[i].iid);
 999                 intent->size = le32_to_cpu(msg->intents[i].size);
1000
1001                 spin_lock_irqsave(&channel->intent_lock, flags);
1002                 ret = idr_alloc(&channel->riids, intent,
1003                                 intent->id, intent->id + 1, GFP_ATOMIC);
1004                 spin_unlock_irqrestore(&channel->intent_lock, flags);
1005
1006                 if (ret < 0)
1007                         dev_err(glink->dev, "failed to store remote intent\n");
1008         }
1009
1010         WRITE_ONCE(channel->intent_received, true);
1011         wake_up_all(&channel->intent_req_wq);
1012
1013         kfree(msg);
1014         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
1015 }
1016
1017 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
1018 {
1019         struct glink_channel *channel;
1020
1021         spin_lock(&glink->idr_lock);
1022         channel = idr_find(&glink->lcids, lcid);
1023         spin_unlock(&glink->idr_lock);
1024         if (!channel) {
1025                 dev_err(glink->dev, "Invalid open ack packet\n");
1026                 return -EINVAL;
1027         }
1028
1029         complete_all(&channel->open_ack);
1030
1031         return 0;
1032 }
1033
1034 /**
1035  * qcom_glink_set_flow_control() - convert a signal cmd to wire format and transmit
1036  * @ept:        Rpmsg endpoint for channel.
1037  * @pause:      Pause transmission
1038  * @dst:        destination address of the endpoint
1039  *
1040  * Return: 0 on success or standard Linux error code.
1041  */
1042 static int qcom_glink_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst)
1043 {
1044         struct glink_channel *channel = to_glink_channel(ept);
1045         struct qcom_glink *glink = channel->glink;
1046         struct glink_msg msg;
1047         u32 sigs = 0;
1048
1049         if (pause)
1050                 sigs |= NATIVE_DTR_SIG | NATIVE_RTS_SIG;
1051
1052         msg.cmd = cpu_to_le16(GLINK_CMD_SIGNALS);
1053         msg.param1 = cpu_to_le16(channel->lcid);
1054         msg.param2 = cpu_to_le32(sigs);
1055
1056         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
1057 }
1058
1059 static void qcom_glink_handle_signals(struct qcom_glink *glink,
1060                                       unsigned int rcid, unsigned int sigs)
1061 {
1062         struct glink_channel *channel;
1063         unsigned long flags;
1064         bool enable;
1065
1066         spin_lock_irqsave(&glink->idr_lock, flags);
1067         channel = idr_find(&glink->rcids, rcid);
1068         spin_unlock_irqrestore(&glink->idr_lock, flags);
1069         if (!channel)
1070                 dev_err(glink->dev, "signal for non-existing channel\n");
1071
1072         enable = sigs & NATIVE_DSR_SIG || sigs & NATIVE_CTS_SIG;
1073
1074         if (channel->ept.flow_cb)
1075                 channel->ept.flow_cb(channel->ept.rpdev, channel->ept.priv, enable);
1076 }
1077
1078 void qcom_glink_native_rx(struct qcom_glink *glink)
1079 {
1080         struct glink_msg msg;
1081         unsigned int param1;
1082         unsigned int param2;
1083         unsigned int avail;
1084         unsigned int cmd;
1085         int ret = 0;
1086
1087         /* To wakeup any blocking writers */
1088         wake_up_all(&glink->tx_avail_notify);
1089
1090         for (;;) {
1091                 avail = qcom_glink_rx_avail(glink);
1092                 if (avail < sizeof(msg))
1093                         break;
1094
1095                 qcom_glink_rx_peek(glink, &msg, 0, sizeof(msg));
1096
1097                 cmd = le16_to_cpu(msg.cmd);
1098                 param1 = le16_to_cpu(msg.param1);
1099                 param2 = le32_to_cpu(msg.param2);
1100
1101                 switch (cmd) {
1102                 case GLINK_CMD_VERSION:
1103                 case GLINK_CMD_VERSION_ACK:
1104                 case GLINK_CMD_CLOSE:
1105                 case GLINK_CMD_CLOSE_ACK:
1106                 case GLINK_CMD_RX_INTENT_REQ:
1107                         ret = qcom_glink_rx_defer(glink, 0);
1108                         break;
1109                 case GLINK_CMD_OPEN_ACK:
1110                         ret = qcom_glink_rx_open_ack(glink, param1);
1111                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1112                         break;
1113                 case GLINK_CMD_OPEN:
1114                         ret = qcom_glink_rx_defer(glink, param2);
1115                         break;
1116                 case GLINK_CMD_TX_DATA:
1117                 case GLINK_CMD_TX_DATA_CONT:
1118                         ret = qcom_glink_rx_data(glink, avail);
1119                         break;
1120                 case GLINK_CMD_READ_NOTIF:
1121                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1122                         qcom_glink_tx_kick(glink);
1123                         break;
1124                 case GLINK_CMD_INTENT:
1125                         qcom_glink_handle_intent(glink, param1, param2, avail);
1126                         break;
1127                 case GLINK_CMD_RX_DONE:
1128                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1129                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1130                         break;
1131                 case GLINK_CMD_RX_DONE_W_REUSE:
1132                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1133                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1134                         break;
1135                 case GLINK_CMD_RX_INTENT_REQ_ACK:
1136                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1137                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1138                         break;
1139                 case GLINK_CMD_SIGNALS:
1140                         qcom_glink_handle_signals(glink, param1, param2);
1141                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1142                         break;
1143                 default:
1144                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1145                         ret = -EINVAL;
1146                         break;
1147                 }
1148
1149                 if (ret)
1150                         break;
1151         }
1152 }
1153 EXPORT_SYMBOL(qcom_glink_native_rx);
1154
1155 /* Locally initiated rpmsg_create_ept */
1156 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1157                                                      const char *name)
1158 {
1159         struct glink_channel *channel;
1160         int ret;
1161         unsigned long flags;
1162
1163         channel = qcom_glink_alloc_channel(glink, name);
1164         if (IS_ERR(channel))
1165                 return ERR_CAST(channel);
1166
1167         ret = qcom_glink_send_open_req(glink, channel);
1168         if (ret)
1169                 goto release_channel;
1170
1171         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1172         if (!ret)
1173                 goto err_timeout;
1174
1175         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1176         if (!ret)
1177                 goto err_timeout;
1178
1179         qcom_glink_send_open_ack(glink, channel);
1180
1181         return channel;
1182
1183 err_timeout:
1184         /* qcom_glink_send_open_req() did register the channel in lcids*/
1185         spin_lock_irqsave(&glink->idr_lock, flags);
1186         idr_remove(&glink->lcids, channel->lcid);
1187         spin_unlock_irqrestore(&glink->idr_lock, flags);
1188
1189 release_channel:
1190         /* Release qcom_glink_send_open_req() reference */
1191         kref_put(&channel->refcount, qcom_glink_channel_release);
1192         /* Release qcom_glink_alloc_channel() reference */
1193         kref_put(&channel->refcount, qcom_glink_channel_release);
1194
1195         return ERR_PTR(-ETIMEDOUT);
1196 }
1197
1198 /* Remote initiated rpmsg_create_ept */
1199 static int qcom_glink_create_remote(struct qcom_glink *glink,
1200                                     struct glink_channel *channel)
1201 {
1202         int ret;
1203
1204         qcom_glink_send_open_ack(glink, channel);
1205
1206         ret = qcom_glink_send_open_req(glink, channel);
1207         if (ret)
1208                 goto close_link;
1209
1210         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1211         if (!ret) {
1212                 ret = -ETIMEDOUT;
1213                 goto close_link;
1214         }
1215
1216         return 0;
1217
1218 close_link:
1219         /*
1220          * Send a close request to "undo" our open-ack. The close-ack will
1221          * release qcom_glink_send_open_req() reference and the last reference
1222          * will be relesed after receiving remote_close or transport unregister
1223          * by calling qcom_glink_native_remove().
1224          */
1225         qcom_glink_send_close_req(glink, channel);
1226
1227         return ret;
1228 }
1229
1230 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1231                                                     rpmsg_rx_cb_t cb,
1232                                                     void *priv,
1233                                                     struct rpmsg_channel_info
1234                                                                         chinfo)
1235 {
1236         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1237         struct glink_channel *channel;
1238         struct qcom_glink *glink = parent->glink;
1239         struct rpmsg_endpoint *ept;
1240         const char *name = chinfo.name;
1241         int cid;
1242         int ret;
1243         unsigned long flags;
1244
1245         spin_lock_irqsave(&glink->idr_lock, flags);
1246         idr_for_each_entry(&glink->rcids, channel, cid) {
1247                 if (!strcmp(channel->name, name))
1248                         break;
1249         }
1250         spin_unlock_irqrestore(&glink->idr_lock, flags);
1251
1252         if (!channel) {
1253                 channel = qcom_glink_create_local(glink, name);
1254                 if (IS_ERR(channel))
1255                         return NULL;
1256         } else {
1257                 ret = qcom_glink_create_remote(glink, channel);
1258                 if (ret)
1259                         return NULL;
1260         }
1261
1262         ept = &channel->ept;
1263         ept->rpdev = rpdev;
1264         ept->cb = cb;
1265         ept->priv = priv;
1266         ept->ops = &glink_endpoint_ops;
1267
1268         return ept;
1269 }
1270
1271 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1272 {
1273         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1274         struct device_node *np = rpdev->dev.of_node;
1275         struct qcom_glink *glink = channel->glink;
1276         struct glink_core_rx_intent *intent;
1277         const struct property *prop = NULL;
1278         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1279         int num_intents;
1280         int num_groups = 1;
1281         __be32 *val = defaults;
1282         int size;
1283
1284         if (glink->intentless || !completion_done(&channel->open_ack))
1285                 return 0;
1286
1287         prop = of_find_property(np, "qcom,intents", NULL);
1288         if (prop) {
1289                 val = prop->value;
1290                 num_groups = prop->length / sizeof(u32) / 2;
1291         }
1292
1293         /* Channel is now open, advertise base set of intents */
1294         while (num_groups--) {
1295                 size = be32_to_cpup(val++);
1296                 num_intents = be32_to_cpup(val++);
1297                 while (num_intents--) {
1298                         intent = qcom_glink_alloc_intent(glink, channel, size,
1299                                                          true);
1300                         if (!intent)
1301                                 break;
1302
1303                         qcom_glink_advertise_intent(glink, channel, intent);
1304                 }
1305         }
1306         return 0;
1307 }
1308
1309 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1310 {
1311         struct glink_channel *channel = to_glink_channel(ept);
1312         struct qcom_glink *glink = channel->glink;
1313         unsigned long flags;
1314
1315         spin_lock_irqsave(&channel->recv_lock, flags);
1316         channel->ept.cb = NULL;
1317         spin_unlock_irqrestore(&channel->recv_lock, flags);
1318
1319         /* Decouple the potential rpdev from the channel */
1320         channel->rpdev = NULL;
1321
1322         qcom_glink_send_close_req(glink, channel);
1323 }
1324
1325 static int qcom_glink_request_intent(struct qcom_glink *glink,
1326                                      struct glink_channel *channel,
1327                                      size_t size)
1328 {
1329         struct {
1330                 u16 id;
1331                 u16 cid;
1332                 u32 size;
1333         } __packed cmd;
1334
1335         int ret;
1336
1337         mutex_lock(&channel->intent_req_lock);
1338
1339         WRITE_ONCE(channel->intent_req_result, -1);
1340         WRITE_ONCE(channel->intent_received, false);
1341
1342         cmd.id = GLINK_CMD_RX_INTENT_REQ;
1343         cmd.cid = channel->lcid;
1344         cmd.size = size;
1345
1346         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1347         if (ret)
1348                 goto unlock;
1349
1350         ret = wait_event_timeout(channel->intent_req_wq,
1351                                  READ_ONCE(channel->intent_req_result) >= 0 &&
1352                                  READ_ONCE(channel->intent_received),
1353                                  10 * HZ);
1354         if (!ret) {
1355                 dev_err(glink->dev, "intent request timed out\n");
1356                 ret = -ETIMEDOUT;
1357         } else {
1358                 ret = READ_ONCE(channel->intent_req_result) ? 0 : -ECANCELED;
1359         }
1360
1361 unlock:
1362         mutex_unlock(&channel->intent_req_lock);
1363         return ret;
1364 }
1365
1366 static int __qcom_glink_send(struct glink_channel *channel,
1367                              void *data, int len, bool wait)
1368 {
1369         struct qcom_glink *glink = channel->glink;
1370         struct glink_core_rx_intent *intent = NULL;
1371         struct glink_core_rx_intent *tmp;
1372         int iid = 0;
1373         struct {
1374                 struct glink_msg msg;
1375                 __le32 chunk_size;
1376                 __le32 left_size;
1377         } __packed req;
1378         int ret;
1379         unsigned long flags;
1380         int chunk_size = len;
1381         size_t offset = 0;
1382
1383         if (!glink->intentless) {
1384                 while (!intent) {
1385                         spin_lock_irqsave(&channel->intent_lock, flags);
1386                         idr_for_each_entry(&channel->riids, tmp, iid) {
1387                                 if (tmp->size >= len && !tmp->in_use) {
1388                                         if (!intent)
1389                                                 intent = tmp;
1390                                         else if (intent->size > tmp->size)
1391                                                 intent = tmp;
1392                                         if (intent->size == len)
1393                                                 break;
1394                                 }
1395                         }
1396                         if (intent)
1397                                 intent->in_use = true;
1398                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1399
1400                         /* We found an available intent */
1401                         if (intent)
1402                                 break;
1403
1404                         if (!wait)
1405                                 return -EBUSY;
1406
1407                         ret = qcom_glink_request_intent(glink, channel, len);
1408                         if (ret < 0)
1409                                 return ret;
1410                 }
1411
1412                 iid = intent->id;
1413         }
1414
1415         while (offset < len) {
1416                 chunk_size = len - offset;
1417                 if (chunk_size > SZ_8K && wait)
1418                         chunk_size = SZ_8K;
1419
1420                 req.msg.cmd = cpu_to_le16(offset == 0 ? GLINK_CMD_TX_DATA : GLINK_CMD_TX_DATA_CONT);
1421                 req.msg.param1 = cpu_to_le16(channel->lcid);
1422                 req.msg.param2 = cpu_to_le32(iid);
1423                 req.chunk_size = cpu_to_le32(chunk_size);
1424                 req.left_size = cpu_to_le32(len - offset - chunk_size);
1425
1426                 ret = qcom_glink_tx(glink, &req, sizeof(req), data + offset, chunk_size, wait);
1427                 if (ret) {
1428                         /* Mark intent available if we failed */
1429                         if (intent)
1430                                 intent->in_use = false;
1431                         return ret;
1432                 }
1433
1434                 offset += chunk_size;
1435         }
1436
1437         return 0;
1438 }
1439
1440 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1441 {
1442         struct glink_channel *channel = to_glink_channel(ept);
1443
1444         return __qcom_glink_send(channel, data, len, true);
1445 }
1446
1447 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1448 {
1449         struct glink_channel *channel = to_glink_channel(ept);
1450
1451         return __qcom_glink_send(channel, data, len, false);
1452 }
1453
1454 static int qcom_glink_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1455 {
1456         struct glink_channel *channel = to_glink_channel(ept);
1457
1458         return __qcom_glink_send(channel, data, len, true);
1459 }
1460
1461 static int qcom_glink_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1462 {
1463         struct glink_channel *channel = to_glink_channel(ept);
1464
1465         return __qcom_glink_send(channel, data, len, false);
1466 }
1467
1468 /*
1469  * Finds the device_node for the glink child interested in this channel.
1470  */
1471 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1472                                                     const char *channel)
1473 {
1474         struct device_node *child;
1475         const char *name;
1476         const char *key;
1477         int ret;
1478
1479         for_each_available_child_of_node(node, child) {
1480                 key = "qcom,glink-channels";
1481                 ret = of_property_read_string(child, key, &name);
1482                 if (ret)
1483                         continue;
1484
1485                 if (strcmp(name, channel) == 0)
1486                         return child;
1487         }
1488
1489         return NULL;
1490 }
1491
1492 static const struct rpmsg_device_ops glink_device_ops = {
1493         .create_ept = qcom_glink_create_ept,
1494         .announce_create = qcom_glink_announce_create,
1495 };
1496
1497 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1498         .destroy_ept = qcom_glink_destroy_ept,
1499         .send = qcom_glink_send,
1500         .sendto = qcom_glink_sendto,
1501         .trysend = qcom_glink_trysend,
1502         .trysendto = qcom_glink_trysendto,
1503         .set_flow_control = qcom_glink_set_flow_control,
1504 };
1505
1506 static void qcom_glink_rpdev_release(struct device *dev)
1507 {
1508         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1509
1510         kfree(rpdev->driver_override);
1511         kfree(rpdev);
1512 }
1513
1514 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1515                               char *name)
1516 {
1517         struct glink_channel *channel;
1518         struct rpmsg_device *rpdev;
1519         bool create_device = false;
1520         struct device_node *node;
1521         int lcid;
1522         int ret;
1523         unsigned long flags;
1524
1525         spin_lock_irqsave(&glink->idr_lock, flags);
1526         idr_for_each_entry(&glink->lcids, channel, lcid) {
1527                 if (!strcmp(channel->name, name))
1528                         break;
1529         }
1530         spin_unlock_irqrestore(&glink->idr_lock, flags);
1531
1532         if (!channel) {
1533                 channel = qcom_glink_alloc_channel(glink, name);
1534                 if (IS_ERR(channel))
1535                         return PTR_ERR(channel);
1536
1537                 /* The opening dance was initiated by the remote */
1538                 create_device = true;
1539         }
1540
1541         spin_lock_irqsave(&glink->idr_lock, flags);
1542         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1543         if (ret < 0) {
1544                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1545                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1546                 goto free_channel;
1547         }
1548         channel->rcid = ret;
1549         spin_unlock_irqrestore(&glink->idr_lock, flags);
1550
1551         complete_all(&channel->open_req);
1552
1553         if (create_device) {
1554                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1555                 if (!rpdev) {
1556                         ret = -ENOMEM;
1557                         goto rcid_remove;
1558                 }
1559
1560                 rpdev->ept = &channel->ept;
1561                 strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE);
1562                 rpdev->src = RPMSG_ADDR_ANY;
1563                 rpdev->dst = RPMSG_ADDR_ANY;
1564                 rpdev->ops = &glink_device_ops;
1565
1566                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1567                 rpdev->dev.of_node = node;
1568                 rpdev->dev.parent = glink->dev;
1569                 rpdev->dev.release = qcom_glink_rpdev_release;
1570
1571                 ret = rpmsg_register_device(rpdev);
1572                 if (ret)
1573                         goto rcid_remove;
1574
1575                 channel->rpdev = rpdev;
1576         }
1577
1578         return 0;
1579
1580 rcid_remove:
1581         spin_lock_irqsave(&glink->idr_lock, flags);
1582         idr_remove(&glink->rcids, channel->rcid);
1583         channel->rcid = 0;
1584         spin_unlock_irqrestore(&glink->idr_lock, flags);
1585 free_channel:
1586         /* Release the reference, iff we took it */
1587         if (create_device)
1588                 kref_put(&channel->refcount, qcom_glink_channel_release);
1589
1590         return ret;
1591 }
1592
1593 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1594 {
1595         struct rpmsg_channel_info chinfo;
1596         struct glink_channel *channel;
1597         unsigned long flags;
1598
1599         spin_lock_irqsave(&glink->idr_lock, flags);
1600         channel = idr_find(&glink->rcids, rcid);
1601         spin_unlock_irqrestore(&glink->idr_lock, flags);
1602         if (WARN(!channel, "close request on unknown channel\n"))
1603                 return;
1604
1605         /* cancel pending rx_done work */
1606         cancel_work_sync(&channel->intent_work);
1607
1608         if (channel->rpdev) {
1609                 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1610                 chinfo.src = RPMSG_ADDR_ANY;
1611                 chinfo.dst = RPMSG_ADDR_ANY;
1612
1613                 rpmsg_unregister_device(glink->dev, &chinfo);
1614         }
1615         channel->rpdev = NULL;
1616
1617         qcom_glink_send_close_ack(glink, channel->rcid);
1618
1619         spin_lock_irqsave(&glink->idr_lock, flags);
1620         idr_remove(&glink->rcids, channel->rcid);
1621         channel->rcid = 0;
1622         spin_unlock_irqrestore(&glink->idr_lock, flags);
1623
1624         kref_put(&channel->refcount, qcom_glink_channel_release);
1625 }
1626
1627 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1628 {
1629         struct rpmsg_channel_info chinfo;
1630         struct glink_channel *channel;
1631         unsigned long flags;
1632
1633         /* To wakeup any blocking writers */
1634         wake_up_all(&glink->tx_avail_notify);
1635
1636         spin_lock_irqsave(&glink->idr_lock, flags);
1637         channel = idr_find(&glink->lcids, lcid);
1638         if (WARN(!channel, "close ack on unknown channel\n")) {
1639                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1640                 return;
1641         }
1642
1643         idr_remove(&glink->lcids, channel->lcid);
1644         channel->lcid = 0;
1645         spin_unlock_irqrestore(&glink->idr_lock, flags);
1646
1647         /* Decouple the potential rpdev from the channel */
1648         if (channel->rpdev) {
1649                 strscpy(chinfo.name, channel->name, sizeof(chinfo.name));
1650                 chinfo.src = RPMSG_ADDR_ANY;
1651                 chinfo.dst = RPMSG_ADDR_ANY;
1652
1653                 rpmsg_unregister_device(glink->dev, &chinfo);
1654         }
1655         channel->rpdev = NULL;
1656
1657         kref_put(&channel->refcount, qcom_glink_channel_release);
1658 }
1659
1660 static void qcom_glink_work(struct work_struct *work)
1661 {
1662         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1663                                                 rx_work);
1664         struct glink_defer_cmd *dcmd;
1665         struct glink_msg *msg;
1666         unsigned long flags;
1667         unsigned int param1;
1668         unsigned int param2;
1669         unsigned int cmd;
1670
1671         for (;;) {
1672                 spin_lock_irqsave(&glink->rx_lock, flags);
1673                 if (list_empty(&glink->rx_queue)) {
1674                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1675                         break;
1676                 }
1677                 dcmd = list_first_entry(&glink->rx_queue,
1678                                         struct glink_defer_cmd, node);
1679                 list_del(&dcmd->node);
1680                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1681
1682                 msg = &dcmd->msg;
1683                 cmd = le16_to_cpu(msg->cmd);
1684                 param1 = le16_to_cpu(msg->param1);
1685                 param2 = le32_to_cpu(msg->param2);
1686
1687                 switch (cmd) {
1688                 case GLINK_CMD_VERSION:
1689                         qcom_glink_receive_version(glink, param1, param2);
1690                         break;
1691                 case GLINK_CMD_VERSION_ACK:
1692                         qcom_glink_receive_version_ack(glink, param1, param2);
1693                         break;
1694                 case GLINK_CMD_OPEN:
1695                         qcom_glink_rx_open(glink, param1, msg->data);
1696                         break;
1697                 case GLINK_CMD_CLOSE:
1698                         qcom_glink_rx_close(glink, param1);
1699                         break;
1700                 case GLINK_CMD_CLOSE_ACK:
1701                         qcom_glink_rx_close_ack(glink, param1);
1702                         break;
1703                 case GLINK_CMD_RX_INTENT_REQ:
1704                         qcom_glink_handle_intent_req(glink, param1, param2);
1705                         break;
1706                 default:
1707                         WARN(1, "Unknown defer object %d\n", cmd);
1708                         break;
1709                 }
1710
1711                 kfree(dcmd);
1712         }
1713 }
1714
1715 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1716 {
1717         struct glink_defer_cmd *dcmd;
1718         struct glink_defer_cmd *tmp;
1719
1720         /* cancel any pending deferred rx_work */
1721         cancel_work_sync(&glink->rx_work);
1722
1723         list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1724                 kfree(dcmd);
1725 }
1726
1727 static ssize_t rpmsg_name_show(struct device *dev,
1728                                struct device_attribute *attr, char *buf)
1729 {
1730         int ret = 0;
1731         const char *name;
1732
1733         ret = of_property_read_string(dev->of_node, "label", &name);
1734         if (ret < 0)
1735                 name = dev->of_node->name;
1736
1737         return sysfs_emit(buf, "%s\n", name);
1738 }
1739 static DEVICE_ATTR_RO(rpmsg_name);
1740
1741 static struct attribute *qcom_glink_attrs[] = {
1742         &dev_attr_rpmsg_name.attr,
1743         NULL
1744 };
1745 ATTRIBUTE_GROUPS(qcom_glink);
1746
1747 static void qcom_glink_device_release(struct device *dev)
1748 {
1749         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1750         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1751
1752         /* Release qcom_glink_alloc_channel() reference */
1753         kref_put(&channel->refcount, qcom_glink_channel_release);
1754         kfree(rpdev->driver_override);
1755         kfree(rpdev);
1756 }
1757
1758 static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1759 {
1760         struct rpmsg_device *rpdev;
1761         struct glink_channel *channel;
1762
1763         rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1764         if (!rpdev)
1765                 return -ENOMEM;
1766
1767         channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1768         if (IS_ERR(channel)) {
1769                 kfree(rpdev);
1770                 return PTR_ERR(channel);
1771         }
1772         channel->rpdev = rpdev;
1773
1774         rpdev->ept = &channel->ept;
1775         rpdev->ops = &glink_device_ops;
1776         rpdev->dev.parent = glink->dev;
1777         rpdev->dev.release = qcom_glink_device_release;
1778
1779         return rpmsg_ctrldev_register_device(rpdev);
1780 }
1781
1782 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1783                                            unsigned long features,
1784                                            struct qcom_glink_pipe *rx,
1785                                            struct qcom_glink_pipe *tx,
1786                                            bool intentless)
1787 {
1788         int ret;
1789         struct qcom_glink *glink;
1790
1791         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1792         if (!glink)
1793                 return ERR_PTR(-ENOMEM);
1794
1795         glink->dev = dev;
1796         glink->tx_pipe = tx;
1797         glink->rx_pipe = rx;
1798
1799         glink->features = features;
1800         glink->intentless = intentless;
1801
1802         spin_lock_init(&glink->tx_lock);
1803         spin_lock_init(&glink->rx_lock);
1804         INIT_LIST_HEAD(&glink->rx_queue);
1805         INIT_WORK(&glink->rx_work, qcom_glink_work);
1806         init_waitqueue_head(&glink->tx_avail_notify);
1807
1808         spin_lock_init(&glink->idr_lock);
1809         idr_init(&glink->lcids);
1810         idr_init(&glink->rcids);
1811
1812         glink->dev->groups = qcom_glink_groups;
1813
1814         ret = device_add_groups(dev, qcom_glink_groups);
1815         if (ret)
1816                 dev_err(dev, "failed to add groups\n");
1817
1818         ret = qcom_glink_send_version(glink);
1819         if (ret)
1820                 return ERR_PTR(ret);
1821
1822         ret = qcom_glink_create_chrdev(glink);
1823         if (ret)
1824                 dev_err(glink->dev, "failed to register chrdev\n");
1825
1826         return glink;
1827 }
1828 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1829
1830 static int qcom_glink_remove_device(struct device *dev, void *data)
1831 {
1832         device_unregister(dev);
1833
1834         return 0;
1835 }
1836
1837 void qcom_glink_native_remove(struct qcom_glink *glink)
1838 {
1839         struct glink_channel *channel;
1840         unsigned long flags;
1841         int cid;
1842         int ret;
1843
1844         qcom_glink_cancel_rx_work(glink);
1845
1846         /* Fail all attempts at sending messages */
1847         spin_lock_irqsave(&glink->tx_lock, flags);
1848         glink->abort_tx = true;
1849         wake_up_all(&glink->tx_avail_notify);
1850         spin_unlock_irqrestore(&glink->tx_lock, flags);
1851
1852         /* Abort any senders waiting for intent requests */
1853         spin_lock_irqsave(&glink->idr_lock, flags);
1854         idr_for_each_entry(&glink->lcids, channel, cid)
1855                 qcom_glink_intent_req_abort(channel);
1856         spin_unlock_irqrestore(&glink->idr_lock, flags);
1857
1858         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1859         if (ret)
1860                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1861
1862         /* Release any defunct local channels, waiting for close-ack */
1863         idr_for_each_entry(&glink->lcids, channel, cid)
1864                 kref_put(&channel->refcount, qcom_glink_channel_release);
1865
1866         /* Release any defunct local channels, waiting for close-req */
1867         idr_for_each_entry(&glink->rcids, channel, cid)
1868                 kref_put(&channel->refcount, qcom_glink_channel_release);
1869
1870         idr_destroy(&glink->lcids);
1871         idr_destroy(&glink->rcids);
1872 }
1873 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1874
1875 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1876 MODULE_LICENSE("GPL v2");