drivers/rpmsg/qcom_glink_native.c

   1 /*
   2  * Copyright (c) 2016-2017, Linaro Ltd
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/idr.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/list.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_irq.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regmap.h>
  25 #include <linux/rpmsg.h>
  26 #include <linux/sizes.h>
  27 #include <linux/slab.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/mailbox_client.h>
  30
  31 #include "rpmsg_internal.h"
  32 #include "qcom_glink_native.h"
  33
  34 #define GLINK_NAME_SIZE         32
  35 #define GLINK_VERSION_1         1
  36
  37 #define RPM_GLINK_CID_MIN       1
  38 #define RPM_GLINK_CID_MAX       65536
  39
  40 struct glink_msg {
  41         __le16 cmd;
  42         __le16 param1;
  43         __le32 param2;
  44         u8 data[];
  45 } __packed;
  46
  47 /**
  48  * struct glink_defer_cmd - deferred incoming control message
  49  * @node:       list node
  50  * @msg:        message header
  51  * data:        payload of the message
  52  *
  53  * Copy of a received control message, to be added to @rx_queue and processed
  54  * by @rx_work of @qcom_glink.
  55  */
  56 struct glink_defer_cmd {
  57         struct list_head node;
  58
  59         struct glink_msg msg;
  60         u8 data[];
  61 };
  62
  63 /**
  64  * struct glink_core_rx_intent - RX intent
  65  * RX intent
  66  *
  67  * data: pointer to the data (may be NULL for zero-copy)
  68  * id: remote or local intent ID
  69  * size: size of the original intent (do not modify)
  70  * reuse: To mark if the intent can be reused after first use
  71  * in_use: To mark if intent is already in use for the channel
  72  * offset: next write offset (initially 0)
  73  */
  74 struct glink_core_rx_intent {
  75         void *data;
  76         u32 id;
  77         size_t size;
  78         bool reuse;
  79         bool in_use;
  80         u32 offset;
  81
  82         struct list_head node;
  83 };
  84
  85 /**
  86  * struct qcom_glink - driver context, relates to one remote subsystem
  87  * @dev:        reference to the associated struct device
  88  * @mbox_client: mailbox client
  89  * @mbox_chan:  mailbox channel
  90  * @rx_pipe:    pipe object for receive FIFO
  91  * @tx_pipe:    pipe object for transmit FIFO
  92  * @irq:        IRQ for signaling incoming events
  93  * @rx_work:    worker for handling received control messages
  94  * @rx_lock:    protects the @rx_queue
  95  * @rx_queue:   queue of received control messages to be processed in @rx_work
  96  * @tx_lock:    synchronizes operations on the tx fifo
  97  * @idr_lock:   synchronizes @lcids and @rcids modifications
  98  * @lcids:      idr of all channels with a known local channel id
  99  * @rcids:      idr of all channels with a known remote channel id
 100  */
 101 struct qcom_glink {
 102         struct device *dev;
 103
 104         struct mbox_client mbox_client;
 105         struct mbox_chan *mbox_chan;
 106
 107         struct qcom_glink_pipe *rx_pipe;
 108         struct qcom_glink_pipe *tx_pipe;
 109
 110         int irq;
 111
 112         struct work_struct rx_work;
 113         spinlock_t rx_lock;
 114         struct list_head rx_queue;
 115
 116         struct mutex tx_lock;
 117
 118         spinlock_t idr_lock;
 119         struct idr lcids;
 120         struct idr rcids;
 121         unsigned long features;
 122
 123         bool intentless;
 124 };
 125
 126 enum {
 127         GLINK_STATE_CLOSED,
 128         GLINK_STATE_OPENING,
 129         GLINK_STATE_OPEN,
 130         GLINK_STATE_CLOSING,
 131 };
 132
 133 /**
 134  * struct glink_channel - internal representation of a channel
 135  * @rpdev:      rpdev reference, only used for primary endpoints
 136  * @ept:        rpmsg endpoint this channel is associated with
 137  * @glink:      qcom_glink context handle
 138  * @refcount:   refcount for the channel object
 139  * @recv_lock:  guard for @ept.cb
 140  * @name:       unique channel name/identifier
 141  * @lcid:       channel id, in local space
 142  * @rcid:       channel id, in remote space
 143  * @intent_lock: lock for protection of @liids, @riids
 144  * @liids:      idr of all local intents
 145  * @riids:      idr of all remote intents
 146  * @intent_work: worker responsible for transmitting rx_done packets
 147  * @done_intents: list of intents that needs to be announced rx_done
 148  * @buf:        receive buffer, for gathering fragments
 149  * @buf_offset: write offset in @buf
 150  * @buf_size:   size of current @buf
 151  * @open_ack:   completed once remote has acked the open-request
 152  * @open_req:   completed once open-request has been received
 153  * @intent_req_lock: Synchronises multiple intent requests
 154  * @intent_req_result: Result of intent request
 155  * @intent_req_comp: Completion for intent_req signalling
 156  */
 157 struct glink_channel {
 158         struct rpmsg_endpoint ept;
 159
 160         struct rpmsg_device *rpdev;
 161         struct qcom_glink *glink;
 162
 163         struct kref refcount;
 164
 165         spinlock_t recv_lock;
 166
 167         char *name;
 168         unsigned int lcid;
 169         unsigned int rcid;
 170
 171         spinlock_t intent_lock;
 172         struct idr liids;
 173         struct idr riids;
 174         struct work_struct intent_work;
 175         struct list_head done_intents;
 176
 177         struct glink_core_rx_intent *buf;
 178         int buf_offset;
 179         int buf_size;
 180
 181         struct completion open_ack;
 182         struct completion open_req;
 183
 184         struct mutex intent_req_lock;
 185         bool intent_req_result;
 186         struct completion intent_req_comp;
 187 };
 188
 189 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 190
 191 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 192
 193 #define RPM_CMD_VERSION                 0
 194 #define RPM_CMD_VERSION_ACK             1
 195 #define RPM_CMD_OPEN                    2
 196 #define RPM_CMD_CLOSE                   3
 197 #define RPM_CMD_OPEN_ACK                4
 198 #define RPM_CMD_INTENT                  5
 199 #define RPM_CMD_RX_DONE                 6
 200 #define RPM_CMD_RX_INTENT_REQ           7
 201 #define RPM_CMD_RX_INTENT_REQ_ACK       8
 202 #define RPM_CMD_TX_DATA                 9
 203 #define RPM_CMD_CLOSE_ACK               11
 204 #define RPM_CMD_TX_DATA_CONT            12
 205 #define RPM_CMD_READ_NOTIF              13
 206 #define RPM_CMD_RX_DONE_W_REUSE         14
 207
 208 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 209
 210 static void qcom_glink_rx_done_work(struct work_struct *work);
 211
 212 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 213                                                       const char *name)
 214 {
 215         struct glink_channel *channel;
 216
 217         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 218         if (!channel)
 219                 return ERR_PTR(-ENOMEM);
 220
 221         /* Setup glink internal glink_channel data */
 222         spin_lock_init(&channel->recv_lock);
 223         spin_lock_init(&channel->intent_lock);
 224
 225         channel->glink = glink;
 226         channel->name = kstrdup(name, GFP_KERNEL);
 227
 228         init_completion(&channel->open_req);
 229         init_completion(&channel->open_ack);
 230
 231         INIT_LIST_HEAD(&channel->done_intents);
 232         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 233
 234         idr_init(&channel->liids);
 235         idr_init(&channel->riids);
 236         kref_init(&channel->refcount);
 237
 238         return channel;
 239 }
 240
 241 static void qcom_glink_channel_release(struct kref *ref)
 242 {
 243         struct glink_channel *channel = container_of(ref, struct glink_channel,
 244                                                      refcount);
 245         unsigned long flags;
 246
 247         spin_lock_irqsave(&channel->intent_lock, flags);
 248         idr_destroy(&channel->liids);
 249         idr_destroy(&channel->riids);
 250         spin_unlock_irqrestore(&channel->intent_lock, flags);
 251
 252         kfree(channel->name);
 253         kfree(channel);
 254 }
 255
 256 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 257 {
 258         return glink->rx_pipe->avail(glink->rx_pipe);
 259 }
 260
 261 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 262                                void *data, unsigned int offset, size_t count)
 263 {
 264         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 265 }
 266
 267 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 268 {
 269         glink->rx_pipe->advance(glink->rx_pipe, count);
 270 }
 271
 272 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 273 {
 274         return glink->tx_pipe->avail(glink->tx_pipe);
 275 }
 276
 277 static void qcom_glink_tx_write(struct qcom_glink *glink,
 278                                 const void *hdr, size_t hlen,
 279                                 const void *data, size_t dlen)
 280 {
 281         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 282 }
 283
 284 static int qcom_glink_tx(struct qcom_glink *glink,
 285                          const void *hdr, size_t hlen,
 286                          const void *data, size_t dlen, bool wait)
 287 {
 288         unsigned int tlen = hlen + dlen;
 289         int ret;
 290
 291         /* Reject packets that are too big */
 292         if (tlen >= glink->tx_pipe->length)
 293                 return -EINVAL;
 294
 295         ret = mutex_lock_interruptible(&glink->tx_lock);
 296         if (ret)
 297                 return ret;
 298
 299         while (qcom_glink_tx_avail(glink) < tlen) {
 300                 if (!wait) {
 301                         ret = -EAGAIN;
 302                         goto out;
 303                 }
 304
 305                 usleep_range(10000, 15000);
 306         }
 307
 308         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 309
 310         mbox_send_message(glink->mbox_chan, NULL);
 311         mbox_client_txdone(glink->mbox_chan, 0);
 312
 313 out:
 314         mutex_unlock(&glink->tx_lock);
 315
 316         return ret;
 317 }
 318
 319 static int qcom_glink_send_version(struct qcom_glink *glink)
 320 {
 321         struct glink_msg msg;
 322
 323         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 324         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 325         msg.param2 = cpu_to_le32(glink->features);
 326
 327         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 328 }
 329
 330 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 331 {
 332         struct glink_msg msg;
 333
 334         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 335         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 336         msg.param2 = cpu_to_le32(glink->features);
 337
 338         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 339 }
 340
 341 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 342                                      struct glink_channel *channel)
 343 {
 344         struct glink_msg msg;
 345
 346         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 347         msg.param1 = cpu_to_le16(channel->rcid);
 348         msg.param2 = cpu_to_le32(0);
 349
 350         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 351 }
 352
 353 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 354                                              unsigned int cid, bool granted)
 355 {
 356         struct glink_channel *channel;
 357         unsigned long flags;
 358
 359         spin_lock_irqsave(&glink->idr_lock, flags);
 360         channel = idr_find(&glink->rcids, cid);
 361         spin_unlock_irqrestore(&glink->idr_lock, flags);
 362         if (!channel) {
 363                 dev_err(glink->dev, "unable to find channel\n");
 364                 return;
 365         }
 366
 367         channel->intent_req_result = granted;
 368         complete(&channel->intent_req_comp);
 369 }
 370
 371 /**
 372  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 373  * @glink: Ptr to the glink edge
 374  * @channel: Ptr to the channel that the open req is sent
 375  *
 376  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 377  * Will return with refcount held, regardless of outcome.
 378  *
 379  * Returns 0 on success, negative errno otherwise.
 380  */
 381 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 382                                     struct glink_channel *channel)
 383 {
 384         struct {
 385                 struct glink_msg msg;
 386                 u8 name[GLINK_NAME_SIZE];
 387         } __packed req;
 388         int name_len = strlen(channel->name) + 1;
 389         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 390         int ret;
 391         unsigned long flags;
 392
 393         kref_get(&channel->refcount);
 394
 395         spin_lock_irqsave(&glink->idr_lock, flags);
 396         ret = idr_alloc_cyclic(&glink->lcids, channel,
 397                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 398                                GFP_ATOMIC);
 399         spin_unlock_irqrestore(&glink->idr_lock, flags);
 400         if (ret < 0)
 401                 return ret;
 402
 403         channel->lcid = ret;
 404
 405         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 406         req.msg.param1 = cpu_to_le16(channel->lcid);
 407         req.msg.param2 = cpu_to_le32(name_len);
 408         strcpy(req.name, channel->name);
 409
 410         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 411         if (ret)
 412                 goto remove_idr;
 413
 414         return 0;
 415
 416 remove_idr:
 417         spin_lock_irqsave(&glink->idr_lock, flags);
 418         idr_remove(&glink->lcids, channel->lcid);
 419         channel->lcid = 0;
 420         spin_unlock_irqrestore(&glink->idr_lock, flags);
 421
 422         return ret;
 423 }
 424
 425 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 426                                       struct glink_channel *channel)
 427 {
 428         struct glink_msg req;
 429
 430         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 431         req.param1 = cpu_to_le16(channel->lcid);
 432         req.param2 = 0;
 433
 434         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 435 }
 436
 437 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 438                                       unsigned int rcid)
 439 {
 440         struct glink_msg req;
 441
 442         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 443         req.param1 = cpu_to_le16(rcid);
 444         req.param2 = 0;
 445
 446         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 447 }
 448
 449 static void qcom_glink_rx_done_work(struct work_struct *work)
 450 {
 451         struct glink_channel *channel = container_of(work, struct glink_channel,
 452                                                      intent_work);
 453         struct qcom_glink *glink = channel->glink;
 454         struct glink_core_rx_intent *intent, *tmp;
 455         struct {
 456                 u16 id;
 457                 u16 lcid;
 458                 u32 liid;
 459         } __packed cmd;
 460
 461         unsigned int cid = channel->lcid;
 462         unsigned int iid;
 463         bool reuse;
 464         unsigned long flags;
 465
 466         spin_lock_irqsave(&channel->intent_lock, flags);
 467         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 468                 list_del(&intent->node);
 469                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 470                 iid = intent->id;
 471                 reuse = intent->reuse;
 472
 473                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 474                 cmd.lcid = cid;
 475                 cmd.liid = iid;
 476
 477                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 478                 if (!reuse) {
 479                         kfree(intent->data);
 480                         kfree(intent);
 481                 }
 482                 spin_lock_irqsave(&channel->intent_lock, flags);
 483         }
 484         spin_unlock_irqrestore(&channel->intent_lock, flags);
 485 }
 486
 487 static void qcom_glink_rx_done(struct qcom_glink *glink,
 488                                struct glink_channel *channel,
 489                                struct glink_core_rx_intent *intent)
 490 {
 491         /* We don't send RX_DONE to intentless systems */
 492         if (glink->intentless) {
 493                 kfree(intent->data);
 494                 kfree(intent);
 495                 return;
 496         }
 497
 498         /* Take it off the tree of receive intents */
 499         if (!intent->reuse) {
 500                 spin_lock(&channel->intent_lock);
 501                 idr_remove(&channel->liids, intent->id);
 502                 spin_unlock(&channel->intent_lock);
 503         }
 504
 505         /* Schedule the sending of a rx_done indication */
 506         spin_lock(&channel->intent_lock);
 507         list_add_tail(&intent->node, &channel->done_intents);
 508         spin_unlock(&channel->intent_lock);
 509
 510         schedule_work(&channel->intent_work);
 511 }
 512
 513 /**
 514  * qcom_glink_receive_version() - receive version/features from remote system
 515  *
 516  * @glink:      pointer to transport interface
 517  * @r_version:  remote version
 518  * @r_features: remote features
 519  *
 520  * This function is called in response to a remote-initiated version/feature
 521  * negotiation sequence.
 522  */
 523 static void qcom_glink_receive_version(struct qcom_glink *glink,
 524                                        u32 version,
 525                                        u32 features)
 526 {
 527         switch (version) {
 528         case 0:
 529                 break;
 530         case GLINK_VERSION_1:
 531                 glink->features &= features;
 532                 /* FALLTHROUGH */
 533         default:
 534                 qcom_glink_send_version_ack(glink);
 535                 break;
 536         }
 537 }
 538
 539 /**
 540  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 541  *
 542  * @glink:      pointer to transport interface
 543  * @r_version:  remote version response
 544  * @r_features: remote features response
 545  *
 546  * This function is called in response to a local-initiated version/feature
 547  * negotiation sequence and is the counter-offer from the remote side based
 548  * upon the initial version and feature set requested.
 549  */
 550 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 551                                            u32 version,
 552                                            u32 features)
 553 {
 554         switch (version) {
 555         case 0:
 556                 /* Version negotiation failed */
 557                 break;
 558         case GLINK_VERSION_1:
 559                 if (features == glink->features)
 560                         break;
 561
 562                 glink->features &= features;
 563                 /* FALLTHROUGH */
 564         default:
 565                 qcom_glink_send_version(glink);
 566                 break;
 567         }
 568 }
 569
 570 /**
 571  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 572                                       wire format and transmit
 573  * @glink:      The transport to transmit on.
 574  * @channel:    The glink channel
 575  * @granted:    The request response to encode.
 576  *
 577  * Return: 0 on success or standard Linux error code.
 578  */
 579 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 580                                           struct glink_channel *channel,
 581                                           bool granted)
 582 {
 583         struct glink_msg msg;
 584
 585         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 586         msg.param1 = cpu_to_le16(channel->lcid);
 587         msg.param2 = cpu_to_le32(granted);
 588
 589         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 590
 591         return 0;
 592 }
 593
 594 /**
 595  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 596  *                         transmit
 597  * @glink:      The transport to transmit on.
 598  * @channel:    The local channel
 599  * @size:       The intent to pass on to remote.
 600  *
 601  * Return: 0 on success or standard Linux error code.
 602  */
 603 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 604                                        struct glink_channel *channel,
 605                                        struct glink_core_rx_intent *intent)
 606 {
 607         struct command {
 608                 u16 id;
 609                 u16 lcid;
 610                 u32 count;
 611                 u32 size;
 612                 u32 liid;
 613         } __packed;
 614         struct command cmd;
 615
 616         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 617         cmd.lcid = cpu_to_le16(channel->lcid);
 618         cmd.count = cpu_to_le32(1);
 619         cmd.size = cpu_to_le32(intent->size);
 620         cmd.liid = cpu_to_le32(intent->id);
 621
 622         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 623
 624         return 0;
 625 }
 626
 627 static struct glink_core_rx_intent *
 628 qcom_glink_alloc_intent(struct qcom_glink *glink,
 629                         struct glink_channel *channel,
 630                         size_t size,
 631                         bool reuseable)
 632 {
 633         struct glink_core_rx_intent *intent;
 634         int ret;
 635         unsigned long flags;
 636
 637         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 638
 639         if (!intent)
 640                 return NULL;
 641
 642         intent->data = kzalloc(size, GFP_KERNEL);
 643         if (!intent->data)
 644                 return NULL;
 645
 646         spin_lock_irqsave(&channel->intent_lock, flags);
 647         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 648         if (ret < 0) {
 649                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 650                 return NULL;
 651         }
 652         spin_unlock_irqrestore(&channel->intent_lock, flags);
 653
 654         intent->id = ret;
 655         intent->size = size;
 656         intent->reuse = reuseable;
 657
 658         return intent;
 659 }
 660
 661 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 662                                       u32 cid, uint32_t iid,
 663                                       bool reuse)
 664 {
 665         struct glink_core_rx_intent *intent;
 666         struct glink_channel *channel;
 667         unsigned long flags;
 668
 669         spin_lock_irqsave(&glink->idr_lock, flags);
 670         channel = idr_find(&glink->rcids, cid);
 671         spin_unlock_irqrestore(&glink->idr_lock, flags);
 672         if (!channel) {
 673                 dev_err(glink->dev, "invalid channel id received\n");
 674                 return;
 675         }
 676
 677         spin_lock_irqsave(&channel->intent_lock, flags);
 678         intent = idr_find(&channel->riids, iid);
 679
 680         if (!intent) {
 681                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 682                 dev_err(glink->dev, "invalid intent id received\n");
 683                 return;
 684         }
 685
 686         intent->in_use = false;
 687
 688         if (!reuse) {
 689                 idr_remove(&channel->riids, intent->id);
 690                 kfree(intent);
 691         }
 692         spin_unlock_irqrestore(&channel->intent_lock, flags);
 693 }
 694
 695 /**
 696  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 697  *                                          from remote side
 698  * if_ptr:      Pointer to the transport interface
 699  * rcid:        Remote channel ID
 700  * size:        size of the intent
 701  *
 702  * The function searches for the local channel to which the request for
 703  * rx_intent has arrived and allocates and notifies the remote back
 704  */
 705 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 706                                          u32 cid, size_t size)
 707 {
 708         struct glink_core_rx_intent *intent;
 709         struct glink_channel *channel;
 710         unsigned long flags;
 711
 712         spin_lock_irqsave(&glink->idr_lock, flags);
 713         channel = idr_find(&glink->rcids, cid);
 714         spin_unlock_irqrestore(&glink->idr_lock, flags);
 715
 716         if (!channel) {
 717                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 718                 return;
 719         }
 720
 721         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 722         if (intent)
 723                 qcom_glink_advertise_intent(glink, channel, intent);
 724
 725         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 726 }
 727
 728 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 729 {
 730         struct glink_defer_cmd *dcmd;
 731
 732         extra = ALIGN(extra, 8);
 733
 734         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 735                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 736                 return -ENXIO;
 737         }
 738
 739         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 740         if (!dcmd)
 741                 return -ENOMEM;
 742
 743         INIT_LIST_HEAD(&dcmd->node);
 744
 745         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 746
 747         spin_lock(&glink->rx_lock);
 748         list_add_tail(&dcmd->node, &glink->rx_queue);
 749         spin_unlock(&glink->rx_lock);
 750
 751         schedule_work(&glink->rx_work);
 752         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 753
 754         return 0;
 755 }
 756
 757 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 758 {
 759         struct glink_core_rx_intent *intent;
 760         struct glink_channel *channel;
 761         struct {
 762                 struct glink_msg msg;
 763                 __le32 chunk_size;
 764                 __le32 left_size;
 765         } __packed hdr;
 766         unsigned int chunk_size;
 767         unsigned int left_size;
 768         unsigned int rcid;
 769         unsigned int liid;
 770         int ret = 0;
 771         unsigned long flags;
 772
 773         if (avail < sizeof(hdr)) {
 774                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 775                 return -EAGAIN;
 776         }
 777
 778         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 779         chunk_size = le32_to_cpu(hdr.chunk_size);
 780         left_size = le32_to_cpu(hdr.left_size);
 781
 782         if (avail < sizeof(hdr) + chunk_size) {
 783                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 784                 return -EAGAIN;
 785         }
 786
 787         if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
 788                 return -EINVAL;
 789
 790         rcid = le16_to_cpu(hdr.msg.param1);
 791         spin_lock_irqsave(&glink->idr_lock, flags);
 792         channel = idr_find(&glink->rcids, rcid);
 793         spin_unlock_irqrestore(&glink->idr_lock, flags);
 794         if (!channel) {
 795                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 796
 797                 /* Drop the message */
 798                 goto advance_rx;
 799         }
 800
 801         if (glink->intentless) {
 802                 /* Might have an ongoing, fragmented, message to append */
 803                 if (!channel->buf) {
 804                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 805                         if (!intent)
 806                                 return -ENOMEM;
 807
 808                         intent->data = kmalloc(chunk_size + left_size,
 809                                                GFP_ATOMIC);
 810                         if (!intent->data) {
 811                                 kfree(intent);
 812                                 return -ENOMEM;
 813                         }
 814
 815                         intent->id = 0xbabababa;
 816                         intent->size = chunk_size + left_size;
 817                         intent->offset = 0;
 818
 819                         channel->buf = intent;
 820                 } else {
 821                         intent = channel->buf;
 822                 }
 823         } else {
 824                 liid = le32_to_cpu(hdr.msg.param2);
 825
 826                 spin_lock_irqsave(&channel->intent_lock, flags);
 827                 intent = idr_find(&channel->liids, liid);
 828                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 829
 830                 if (!intent) {
 831                         dev_err(glink->dev,
 832                                 "no intent found for channel %s intent %d",
 833                                 channel->name, liid);
 834                         goto advance_rx;
 835                 }
 836         }
 837
 838         if (intent->size - intent->offset < chunk_size) {
 839                 dev_err(glink->dev, "Insufficient space in intent\n");
 840
 841                 /* The packet header lied, drop payload */
 842                 goto advance_rx;
 843         }
 844
 845         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 846                            sizeof(hdr), chunk_size);
 847         intent->offset += chunk_size;
 848
 849         /* Handle message when no fragments remain to be received */
 850         if (!left_size) {
 851                 spin_lock(&channel->recv_lock);
 852                 if (channel->ept.cb) {
 853                         channel->ept.cb(channel->ept.rpdev,
 854                                         intent->data,
 855                                         intent->offset,
 856                                         channel->ept.priv,
 857                                         RPMSG_ADDR_ANY);
 858                 }
 859                 spin_unlock(&channel->recv_lock);
 860
 861                 intent->offset = 0;
 862                 channel->buf = NULL;
 863
 864                 qcom_glink_rx_done(glink, channel, intent);
 865         }
 866
 867 advance_rx:
 868         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 869
 870         return ret;
 871 }
 872
 873 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 874                                      unsigned int cid,
 875                                      unsigned int count,
 876                                      size_t avail)
 877 {
 878         struct glink_core_rx_intent *intent;
 879         struct glink_channel *channel;
 880         struct intent_pair {
 881                 __le32 size;
 882                 __le32 iid;
 883         };
 884
 885         struct {
 886                 struct glink_msg msg;
 887                 struct intent_pair intents[];
 888         } __packed * msg;
 889
 890         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
 891         int ret;
 892         int i;
 893         unsigned long flags;
 894
 895         if (avail < msglen) {
 896                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 897                 return;
 898         }
 899
 900         spin_lock_irqsave(&glink->idr_lock, flags);
 901         channel = idr_find(&glink->rcids, cid);
 902         spin_unlock_irqrestore(&glink->idr_lock, flags);
 903         if (!channel) {
 904                 dev_err(glink->dev, "intents for non-existing channel\n");
 905                 return;
 906         }
 907
 908         msg = kmalloc(msglen, GFP_ATOMIC);
 909         if (!msg)
 910                 return;
 911
 912         qcom_glink_rx_peak(glink, msg, 0, msglen);
 913
 914         for (i = 0; i < count; ++i) {
 915                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 916                 if (!intent)
 917                         break;
 918
 919                 intent->id = le32_to_cpu(msg->intents[i].iid);
 920                 intent->size = le32_to_cpu(msg->intents[i].size);
 921
 922                 spin_lock_irqsave(&channel->intent_lock, flags);
 923                 ret = idr_alloc(&channel->riids, intent,
 924                                 intent->id, intent->id + 1, GFP_ATOMIC);
 925                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 926
 927                 if (ret < 0)
 928                         dev_err(glink->dev, "failed to store remote intent\n");
 929         }
 930
 931         kfree(msg);
 932         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 933 }
 934
 935 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 936 {
 937         struct glink_channel *channel;
 938
 939         spin_lock(&glink->idr_lock);
 940         channel = idr_find(&glink->lcids, lcid);
 941         spin_unlock(&glink->idr_lock);
 942         if (!channel) {
 943                 dev_err(glink->dev, "Invalid open ack packet\n");
 944                 return -EINVAL;
 945         }
 946
 947         complete(&channel->open_ack);
 948
 949         return 0;
 950 }
 951
 952 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 953 {
 954         struct qcom_glink *glink = data;
 955         struct glink_msg msg;
 956         unsigned int param1;
 957         unsigned int param2;
 958         unsigned int avail;
 959         unsigned int cmd;
 960         int ret = 0;
 961
 962         for (;;) {
 963                 avail = qcom_glink_rx_avail(glink);
 964                 if (avail < sizeof(msg))
 965                         break;
 966
 967                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 968
 969                 cmd = le16_to_cpu(msg.cmd);
 970                 param1 = le16_to_cpu(msg.param1);
 971                 param2 = le32_to_cpu(msg.param2);
 972
 973                 switch (cmd) {
 974                 case RPM_CMD_VERSION:
 975                 case RPM_CMD_VERSION_ACK:
 976                 case RPM_CMD_CLOSE:
 977                 case RPM_CMD_CLOSE_ACK:
 978                 case RPM_CMD_RX_INTENT_REQ:
 979                         ret = qcom_glink_rx_defer(glink, 0);
 980                         break;
 981                 case RPM_CMD_OPEN_ACK:
 982                         ret = qcom_glink_rx_open_ack(glink, param1);
 983                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 984                         break;
 985                 case RPM_CMD_OPEN:
 986                         ret = qcom_glink_rx_defer(glink, param2);
 987                         break;
 988                 case RPM_CMD_TX_DATA:
 989                 case RPM_CMD_TX_DATA_CONT:
 990                         ret = qcom_glink_rx_data(glink, avail);
 991                         break;
 992                 case RPM_CMD_READ_NOTIF:
 993                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 994
 995                         mbox_send_message(glink->mbox_chan, NULL);
 996                         mbox_client_txdone(glink->mbox_chan, 0);
 997                         break;
 998                 case RPM_CMD_INTENT:
 999                         qcom_glink_handle_intent(glink, param1, param2, avail);
1000                         break;
1001                 case RPM_CMD_RX_DONE:
1002                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1003                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1004                         break;
1005                 case RPM_CMD_RX_DONE_W_REUSE:
1006                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1007                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1008                         break;
1009                 case RPM_CMD_RX_INTENT_REQ_ACK:
1010                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1011                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1012                         break;
1013                 default:
1014                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1015                         ret = -EINVAL;
1016                         break;
1017                 }
1018
1019                 if (ret)
1020                         break;
1021         }
1022
1023         return IRQ_HANDLED;
1024 }
1025
1026 /* Locally initiated rpmsg_create_ept */
1027 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1028                                                      const char *name)
1029 {
1030         struct glink_channel *channel;
1031         int ret;
1032         unsigned long flags;
1033
1034         channel = qcom_glink_alloc_channel(glink, name);
1035         if (IS_ERR(channel))
1036                 return ERR_CAST(channel);
1037
1038         ret = qcom_glink_send_open_req(glink, channel);
1039         if (ret)
1040                 goto release_channel;
1041
1042         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1043         if (!ret)
1044                 goto err_timeout;
1045
1046         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1047         if (!ret)
1048                 goto err_timeout;
1049
1050         qcom_glink_send_open_ack(glink, channel);
1051
1052         return channel;
1053
1054 err_timeout:
1055         /* qcom_glink_send_open_req() did register the channel in lcids*/
1056         spin_lock_irqsave(&glink->idr_lock, flags);
1057         idr_remove(&glink->lcids, channel->lcid);
1058         spin_unlock_irqrestore(&glink->idr_lock, flags);
1059
1060 release_channel:
1061         /* Release qcom_glink_send_open_req() reference */
1062         kref_put(&channel->refcount, qcom_glink_channel_release);
1063         /* Release qcom_glink_alloc_channel() reference */
1064         kref_put(&channel->refcount, qcom_glink_channel_release);
1065
1066         return ERR_PTR(-ETIMEDOUT);
1067 }
1068
1069 /* Remote initiated rpmsg_create_ept */
1070 static int qcom_glink_create_remote(struct qcom_glink *glink,
1071                                     struct glink_channel *channel)
1072 {
1073         int ret;
1074
1075         qcom_glink_send_open_ack(glink, channel);
1076
1077         ret = qcom_glink_send_open_req(glink, channel);
1078         if (ret)
1079                 goto close_link;
1080
1081         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1082         if (!ret) {
1083                 ret = -ETIMEDOUT;
1084                 goto close_link;
1085         }
1086
1087         return 0;
1088
1089 close_link:
1090         /*
1091          * Send a close request to "undo" our open-ack. The close-ack will
1092          * release the last reference.
1093          */
1094         qcom_glink_send_close_req(glink, channel);
1095
1096         /* Release qcom_glink_send_open_req() reference */
1097         kref_put(&channel->refcount, qcom_glink_channel_release);
1098
1099         return ret;
1100 }
1101
1102 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1103                                                     rpmsg_rx_cb_t cb,
1104                                                     void *priv,
1105                                                     struct rpmsg_channel_info
1106                                                                         chinfo)
1107 {
1108         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1109         struct glink_channel *channel;
1110         struct qcom_glink *glink = parent->glink;
1111         struct rpmsg_endpoint *ept;
1112         const char *name = chinfo.name;
1113         int cid;
1114         int ret;
1115         unsigned long flags;
1116
1117         spin_lock_irqsave(&glink->idr_lock, flags);
1118         idr_for_each_entry(&glink->rcids, channel, cid) {
1119                 if (!strcmp(channel->name, name))
1120                         break;
1121         }
1122         spin_unlock_irqrestore(&glink->idr_lock, flags);
1123
1124         if (!channel) {
1125                 channel = qcom_glink_create_local(glink, name);
1126                 if (IS_ERR(channel))
1127                         return NULL;
1128         } else {
1129                 ret = qcom_glink_create_remote(glink, channel);
1130                 if (ret)
1131                         return NULL;
1132         }
1133
1134         ept = &channel->ept;
1135         ept->rpdev = rpdev;
1136         ept->cb = cb;
1137         ept->priv = priv;
1138         ept->ops = &glink_endpoint_ops;
1139
1140         return ept;
1141 }
1142
1143 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1144 {
1145         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1146         struct glink_core_rx_intent *intent;
1147         struct qcom_glink *glink = channel->glink;
1148         int num_intents = glink->intentless ? 0 : 5;
1149
1150         /* Channel is now open, advertise base set of intents */
1151         while (num_intents--) {
1152                 intent = qcom_glink_alloc_intent(glink, channel, SZ_1K, true);
1153                 if (!intent)
1154                         break;
1155
1156                 qcom_glink_advertise_intent(glink, channel, intent);
1157         }
1158
1159         return 0;
1160 }
1161
1162 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1163 {
1164         struct glink_channel *channel = to_glink_channel(ept);
1165         struct qcom_glink *glink = channel->glink;
1166         unsigned long flags;
1167
1168         spin_lock_irqsave(&channel->recv_lock, flags);
1169         channel->ept.cb = NULL;
1170         spin_unlock_irqrestore(&channel->recv_lock, flags);
1171
1172         /* Decouple the potential rpdev from the channel */
1173         channel->rpdev = NULL;
1174
1175         qcom_glink_send_close_req(glink, channel);
1176 }
1177
1178 static int qcom_glink_request_intent(struct qcom_glink *glink,
1179                                      struct glink_channel *channel,
1180                                      size_t size)
1181 {
1182         struct {
1183                 u16 id;
1184                 u16 cid;
1185                 u32 size;
1186         } __packed cmd;
1187
1188         int ret;
1189
1190         mutex_lock(&channel->intent_req_lock);
1191
1192         reinit_completion(&channel->intent_req_comp);
1193
1194         cmd.id = RPM_CMD_RX_INTENT_REQ;
1195         cmd.cid = channel->lcid;
1196         cmd.size = size;
1197
1198         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1199         if (ret)
1200                 return ret;
1201
1202         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1203         if (!ret) {
1204                 dev_err(glink->dev, "intent request timed out\n");
1205                 ret = -ETIMEDOUT;
1206         } else {
1207                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1208         }
1209
1210         mutex_unlock(&channel->intent_req_lock);
1211         return ret;
1212 }
1213
1214 static int __qcom_glink_send(struct glink_channel *channel,
1215                              void *data, int len, bool wait)
1216 {
1217         struct qcom_glink *glink = channel->glink;
1218         struct glink_core_rx_intent *intent = NULL;
1219         struct glink_core_rx_intent *tmp;
1220         int iid = 0;
1221         struct {
1222                 struct glink_msg msg;
1223                 __le32 chunk_size;
1224                 __le32 left_size;
1225         } __packed req;
1226         int ret;
1227         unsigned long flags;
1228
1229         if (!glink->intentless) {
1230                 while (!intent) {
1231                         spin_lock_irqsave(&channel->intent_lock, flags);
1232                         idr_for_each_entry(&channel->riids, tmp, iid) {
1233                                 if (tmp->size >= len && !tmp->in_use) {
1234                                         tmp->in_use = true;
1235                                         intent = tmp;
1236                                         break;
1237                                 }
1238                         }
1239                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1240
1241                         /* We found an available intent */
1242                         if (intent)
1243                                 break;
1244
1245                         if (!wait)
1246                                 return -EBUSY;
1247
1248                         ret = qcom_glink_request_intent(glink, channel, len);
1249                         if (ret < 0)
1250                                 return ret;
1251                 }
1252
1253                 iid = intent->id;
1254         }
1255
1256         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1257         req.msg.param1 = cpu_to_le16(channel->lcid);
1258         req.msg.param2 = cpu_to_le32(iid);
1259         req.chunk_size = cpu_to_le32(len);
1260         req.left_size = cpu_to_le32(0);
1261
1262         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1263
1264         /* Mark intent available if we failed */
1265         if (ret && intent)
1266                 intent->in_use = false;
1267
1268         return ret;
1269 }
1270
1271 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1272 {
1273         struct glink_channel *channel = to_glink_channel(ept);
1274
1275         return __qcom_glink_send(channel, data, len, true);
1276 }
1277
1278 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1279 {
1280         struct glink_channel *channel = to_glink_channel(ept);
1281
1282         return __qcom_glink_send(channel, data, len, false);
1283 }
1284
1285 /*
1286  * Finds the device_node for the glink child interested in this channel.
1287  */
1288 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1289                                                     const char *channel)
1290 {
1291         struct device_node *child;
1292         const char *name;
1293         const char *key;
1294         int ret;
1295
1296         for_each_available_child_of_node(node, child) {
1297                 key = "qcom,glink-channels";
1298                 ret = of_property_read_string(child, key, &name);
1299                 if (ret)
1300                         continue;
1301
1302                 if (strcmp(name, channel) == 0)
1303                         return child;
1304         }
1305
1306         return NULL;
1307 }
1308
1309 static const struct rpmsg_device_ops glink_device_ops = {
1310         .create_ept = qcom_glink_create_ept,
1311         .announce_create = qcom_glink_announce_create,
1312 };
1313
1314 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1315         .destroy_ept = qcom_glink_destroy_ept,
1316         .send = qcom_glink_send,
1317         .trysend = qcom_glink_trysend,
1318 };
1319
1320 static void qcom_glink_rpdev_release(struct device *dev)
1321 {
1322         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1323         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1324
1325         channel->rpdev = NULL;
1326         kfree(rpdev);
1327 }
1328
1329 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1330                               char *name)
1331 {
1332         struct glink_channel *channel;
1333         struct rpmsg_device *rpdev;
1334         bool create_device = false;
1335         struct device_node *node;
1336         int lcid;
1337         int ret;
1338         unsigned long flags;
1339
1340         spin_lock_irqsave(&glink->idr_lock, flags);
1341         idr_for_each_entry(&glink->lcids, channel, lcid) {
1342                 if (!strcmp(channel->name, name))
1343                         break;
1344         }
1345         spin_unlock_irqrestore(&glink->idr_lock, flags);
1346
1347         if (!channel) {
1348                 channel = qcom_glink_alloc_channel(glink, name);
1349                 if (IS_ERR(channel))
1350                         return PTR_ERR(channel);
1351
1352                 /* The opening dance was initiated by the remote */
1353                 create_device = true;
1354         }
1355
1356         spin_lock_irqsave(&glink->idr_lock, flags);
1357         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1358         if (ret < 0) {
1359                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1360                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1361                 goto free_channel;
1362         }
1363         channel->rcid = ret;
1364         spin_unlock_irqrestore(&glink->idr_lock, flags);
1365
1366         complete(&channel->open_req);
1367
1368         if (create_device) {
1369                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1370                 if (!rpdev) {
1371                         ret = -ENOMEM;
1372                         goto rcid_remove;
1373                 }
1374
1375                 rpdev->ept = &channel->ept;
1376                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1377                 rpdev->src = RPMSG_ADDR_ANY;
1378                 rpdev->dst = RPMSG_ADDR_ANY;
1379                 rpdev->ops = &glink_device_ops;
1380
1381                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1382                 rpdev->dev.of_node = node;
1383                 rpdev->dev.parent = glink->dev;
1384                 rpdev->dev.release = qcom_glink_rpdev_release;
1385
1386                 ret = rpmsg_register_device(rpdev);
1387                 if (ret)
1388                         goto free_rpdev;
1389
1390                 channel->rpdev = rpdev;
1391         }
1392
1393         return 0;
1394
1395 free_rpdev:
1396         kfree(rpdev);
1397 rcid_remove:
1398         spin_lock_irqsave(&glink->idr_lock, flags);
1399         idr_remove(&glink->rcids, channel->rcid);
1400         channel->rcid = 0;
1401         spin_unlock_irqrestore(&glink->idr_lock, flags);
1402 free_channel:
1403         /* Release the reference, iff we took it */
1404         if (create_device)
1405                 kref_put(&channel->refcount, qcom_glink_channel_release);
1406
1407         return ret;
1408 }
1409
1410 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1411 {
1412         struct rpmsg_channel_info chinfo;
1413         struct glink_channel *channel;
1414         unsigned long flags;
1415
1416         spin_lock_irqsave(&glink->idr_lock, flags);
1417         channel = idr_find(&glink->rcids, rcid);
1418         spin_unlock_irqrestore(&glink->idr_lock, flags);
1419         if (WARN(!channel, "close request on unknown channel\n"))
1420                 return;
1421
1422         /* cancel pending rx_done work */
1423         cancel_work_sync(&channel->intent_work);
1424
1425         if (channel->rpdev) {
1426                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1427                 chinfo.src = RPMSG_ADDR_ANY;
1428                 chinfo.dst = RPMSG_ADDR_ANY;
1429
1430                 rpmsg_unregister_device(glink->dev, &chinfo);
1431         }
1432
1433         qcom_glink_send_close_ack(glink, channel->rcid);
1434
1435         spin_lock_irqsave(&glink->idr_lock, flags);
1436         idr_remove(&glink->rcids, channel->rcid);
1437         channel->rcid = 0;
1438         spin_unlock_irqrestore(&glink->idr_lock, flags);
1439
1440         kref_put(&channel->refcount, qcom_glink_channel_release);
1441 }
1442
1443 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1444 {
1445         struct glink_channel *channel;
1446         unsigned long flags;
1447
1448         spin_lock_irqsave(&glink->idr_lock, flags);
1449         channel = idr_find(&glink->lcids, lcid);
1450         if (WARN(!channel, "close ack on unknown channel\n")) {
1451                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1452                 return;
1453         }
1454
1455         idr_remove(&glink->lcids, channel->lcid);
1456         channel->lcid = 0;
1457         spin_unlock_irqrestore(&glink->idr_lock, flags);
1458
1459         kref_put(&channel->refcount, qcom_glink_channel_release);
1460 }
1461
1462 static void qcom_glink_work(struct work_struct *work)
1463 {
1464         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1465                                                 rx_work);
1466         struct glink_defer_cmd *dcmd;
1467         struct glink_msg *msg;
1468         unsigned long flags;
1469         unsigned int param1;
1470         unsigned int param2;
1471         unsigned int cmd;
1472
1473         for (;;) {
1474                 spin_lock_irqsave(&glink->rx_lock, flags);
1475                 if (list_empty(&glink->rx_queue)) {
1476                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1477                         break;
1478                 }
1479                 dcmd = list_first_entry(&glink->rx_queue,
1480                                         struct glink_defer_cmd, node);
1481                 list_del(&dcmd->node);
1482                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1483
1484                 msg = &dcmd->msg;
1485                 cmd = le16_to_cpu(msg->cmd);
1486                 param1 = le16_to_cpu(msg->param1);
1487                 param2 = le32_to_cpu(msg->param2);
1488
1489                 switch (cmd) {
1490                 case RPM_CMD_VERSION:
1491                         qcom_glink_receive_version(glink, param1, param2);
1492                         break;
1493                 case RPM_CMD_VERSION_ACK:
1494                         qcom_glink_receive_version_ack(glink, param1, param2);
1495                         break;
1496                 case RPM_CMD_OPEN:
1497                         qcom_glink_rx_open(glink, param1, msg->data);
1498                         break;
1499                 case RPM_CMD_CLOSE:
1500                         qcom_glink_rx_close(glink, param1);
1501                         break;
1502                 case RPM_CMD_CLOSE_ACK:
1503                         qcom_glink_rx_close_ack(glink, param1);
1504                         break;
1505                 case RPM_CMD_RX_INTENT_REQ:
1506                         qcom_glink_handle_intent_req(glink, param1, param2);
1507                         break;
1508                 default:
1509                         WARN(1, "Unknown defer object %d\n", cmd);
1510                         break;
1511                 }
1512
1513                 kfree(dcmd);
1514         }
1515 }
1516
1517 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1518                                            unsigned long features,
1519                                            struct qcom_glink_pipe *rx,
1520                                            struct qcom_glink_pipe *tx,
1521                                            bool intentless)
1522 {
1523         int irq;
1524         int ret;
1525         struct qcom_glink *glink;
1526
1527         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1528         if (!glink)
1529                 return ERR_PTR(-ENOMEM);
1530
1531         glink->dev = dev;
1532         glink->tx_pipe = tx;
1533         glink->rx_pipe = rx;
1534
1535         glink->features = features;
1536         glink->intentless = intentless;
1537
1538         mutex_init(&glink->tx_lock);
1539         spin_lock_init(&glink->rx_lock);
1540         INIT_LIST_HEAD(&glink->rx_queue);
1541         INIT_WORK(&glink->rx_work, qcom_glink_work);
1542
1543         spin_lock_init(&glink->idr_lock);
1544         idr_init(&glink->lcids);
1545         idr_init(&glink->rcids);
1546
1547         glink->mbox_client.dev = dev;
1548         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1549         if (IS_ERR(glink->mbox_chan)) {
1550                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1551                         dev_err(dev, "failed to acquire IPC channel\n");
1552                 return ERR_CAST(glink->mbox_chan);
1553         }
1554
1555         irq = of_irq_get(dev->of_node, 0);
1556         ret = devm_request_irq(dev, irq,
1557                                qcom_glink_native_intr,
1558                                IRQF_NO_SUSPEND | IRQF_SHARED,
1559                                "glink-native", glink);
1560         if (ret) {
1561                 dev_err(dev, "failed to request IRQ\n");
1562                 return ERR_PTR(ret);
1563         }
1564
1565         glink->irq = irq;
1566
1567         ret = qcom_glink_send_version(glink);
1568         if (ret)
1569                 return ERR_PTR(ret);
1570
1571         return glink;
1572 }
1573 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1574
1575 static int qcom_glink_remove_device(struct device *dev, void *data)
1576 {
1577         device_unregister(dev);
1578
1579         return 0;
1580 }
1581
1582 void qcom_glink_native_remove(struct qcom_glink *glink)
1583 {
1584         struct glink_channel *channel;
1585         int cid;
1586         int ret;
1587         unsigned long flags;
1588
1589         disable_irq(glink->irq);
1590         cancel_work_sync(&glink->rx_work);
1591
1592         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1593         if (ret)
1594                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1595
1596         spin_lock_irqsave(&glink->idr_lock, flags);
1597         /* Release any defunct local channels, waiting for close-ack */
1598         idr_for_each_entry(&glink->lcids, channel, cid)
1599                 kref_put(&channel->refcount, qcom_glink_channel_release);
1600
1601         idr_destroy(&glink->lcids);
1602         idr_destroy(&glink->rcids);
1603         spin_unlock_irqrestore(&glink->idr_lock, flags);
1604         mbox_free_channel(glink->mbox_chan);
1605 }
1606 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1607
1608 void qcom_glink_native_unregister(struct qcom_glink *glink)
1609 {
1610         device_unregister(glink->dev);
1611 }
1612 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);