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/of_irq.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17 #include <linux/rpmsg.h>
  18 #include <linux/sizes.h>
  19 #include <linux/slab.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  * @mbox_client: mailbox client
  82  * @mbox_chan:  mailbox channel
  83  * @rx_pipe:    pipe object for receive FIFO
  84  * @tx_pipe:    pipe object for transmit FIFO
  85  * @irq:        IRQ for signaling incoming events
  86  * @rx_work:    worker for handling received control messages
  87  * @rx_lock:    protects the @rx_queue
  88  * @rx_queue:   queue of received control messages to be processed in @rx_work
  89  * @tx_lock:    synchronizes operations on the tx fifo
  90  * @idr_lock:   synchronizes @lcids and @rcids modifications
  91  * @lcids:      idr of all channels with a known local channel id
  92  * @rcids:      idr of all channels with a known remote channel id
  93  * @features:   remote features
  94  * @intentless: flag to indicate that there is no intent
  95  */
  96 struct qcom_glink {
  97         struct device *dev;
  98
  99         struct mbox_client mbox_client;
 100         struct mbox_chan *mbox_chan;
 101
 102         struct qcom_glink_pipe *rx_pipe;
 103         struct qcom_glink_pipe *tx_pipe;
 104
 105         int irq;
 106
 107         struct work_struct rx_work;
 108         spinlock_t rx_lock;
 109         struct list_head rx_queue;
 110
 111         spinlock_t tx_lock;
 112
 113         spinlock_t idr_lock;
 114         struct idr lcids;
 115         struct idr rcids;
 116         unsigned long features;
 117
 118         bool intentless;
 119 };
 120
 121 enum {
 122         GLINK_STATE_CLOSED,
 123         GLINK_STATE_OPENING,
 124         GLINK_STATE_OPEN,
 125         GLINK_STATE_CLOSING,
 126 };
 127
 128 /**
 129  * struct glink_channel - internal representation of a channel
 130  * @rpdev:      rpdev reference, only used for primary endpoints
 131  * @ept:        rpmsg endpoint this channel is associated with
 132  * @glink:      qcom_glink context handle
 133  * @refcount:   refcount for the channel object
 134  * @recv_lock:  guard for @ept.cb
 135  * @name:       unique channel name/identifier
 136  * @lcid:       channel id, in local space
 137  * @rcid:       channel id, in remote space
 138  * @intent_lock: lock for protection of @liids, @riids
 139  * @liids:      idr of all local intents
 140  * @riids:      idr of all remote intents
 141  * @intent_work: worker responsible for transmitting rx_done packets
 142  * @done_intents: list of intents that needs to be announced rx_done
 143  * @buf:        receive buffer, for gathering fragments
 144  * @buf_offset: write offset in @buf
 145  * @buf_size:   size of current @buf
 146  * @open_ack:   completed once remote has acked the open-request
 147  * @open_req:   completed once open-request has been received
 148  * @intent_req_lock: Synchronises multiple intent requests
 149  * @intent_req_result: Result of intent request
 150  * @intent_req_comp: Completion 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         bool intent_req_result;
 181         struct completion intent_req_comp;
 182 };
 183
 184 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 185
 186 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 187
 188 #define RPM_CMD_VERSION                 0
 189 #define RPM_CMD_VERSION_ACK             1
 190 #define RPM_CMD_OPEN                    2
 191 #define RPM_CMD_CLOSE                   3
 192 #define RPM_CMD_OPEN_ACK                4
 193 #define RPM_CMD_INTENT                  5
 194 #define RPM_CMD_RX_DONE                 6
 195 #define RPM_CMD_RX_INTENT_REQ           7
 196 #define RPM_CMD_RX_INTENT_REQ_ACK       8
 197 #define RPM_CMD_TX_DATA                 9
 198 #define RPM_CMD_CLOSE_ACK               11
 199 #define RPM_CMD_TX_DATA_CONT            12
 200 #define RPM_CMD_READ_NOTIF              13
 201 #define RPM_CMD_RX_DONE_W_REUSE         14
 202
 203 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 204
 205 static void qcom_glink_rx_done_work(struct work_struct *work);
 206
 207 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 208                                                       const char *name)
 209 {
 210         struct glink_channel *channel;
 211
 212         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 213         if (!channel)
 214                 return ERR_PTR(-ENOMEM);
 215
 216         /* Setup glink internal glink_channel data */
 217         spin_lock_init(&channel->recv_lock);
 218         spin_lock_init(&channel->intent_lock);
 219         mutex_init(&channel->intent_req_lock);
 220
 221         channel->glink = glink;
 222         channel->name = kstrdup(name, GFP_KERNEL);
 223
 224         init_completion(&channel->open_req);
 225         init_completion(&channel->open_ack);
 226         init_completion(&channel->intent_req_comp);
 227
 228         INIT_LIST_HEAD(&channel->done_intents);
 229         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 230
 231         idr_init(&channel->liids);
 232         idr_init(&channel->riids);
 233         kref_init(&channel->refcount);
 234
 235         return channel;
 236 }
 237
 238 static void qcom_glink_channel_release(struct kref *ref)
 239 {
 240         struct glink_channel *channel = container_of(ref, struct glink_channel,
 241                                                      refcount);
 242         unsigned long flags;
 243
 244         spin_lock_irqsave(&channel->intent_lock, flags);
 245         idr_destroy(&channel->liids);
 246         idr_destroy(&channel->riids);
 247         spin_unlock_irqrestore(&channel->intent_lock, flags);
 248
 249         kfree(channel->name);
 250         kfree(channel);
 251 }
 252
 253 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 254 {
 255         return glink->rx_pipe->avail(glink->rx_pipe);
 256 }
 257
 258 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 259                                void *data, unsigned int offset, size_t count)
 260 {
 261         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 262 }
 263
 264 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 265 {
 266         glink->rx_pipe->advance(glink->rx_pipe, count);
 267 }
 268
 269 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 270 {
 271         return glink->tx_pipe->avail(glink->tx_pipe);
 272 }
 273
 274 static void qcom_glink_tx_write(struct qcom_glink *glink,
 275                                 const void *hdr, size_t hlen,
 276                                 const void *data, size_t dlen)
 277 {
 278         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 279 }
 280
 281 static int qcom_glink_tx(struct qcom_glink *glink,
 282                          const void *hdr, size_t hlen,
 283                          const void *data, size_t dlen, bool wait)
 284 {
 285         unsigned int tlen = hlen + dlen;
 286         unsigned long flags;
 287         int ret = 0;
 288
 289         /* Reject packets that are too big */
 290         if (tlen >= glink->tx_pipe->length)
 291                 return -EINVAL;
 292
 293         spin_lock_irqsave(&glink->tx_lock, flags);
 294
 295         while (qcom_glink_tx_avail(glink) < tlen) {
 296                 if (!wait) {
 297                         ret = -EAGAIN;
 298                         goto out;
 299                 }
 300
 301                 /* Wait without holding the tx_lock */
 302                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 303
 304                 usleep_range(10000, 15000);
 305
 306                 spin_lock_irqsave(&glink->tx_lock, flags);
 307         }
 308
 309         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 310
 311         mbox_send_message(glink->mbox_chan, NULL);
 312         mbox_client_txdone(glink->mbox_chan, 0);
 313
 314 out:
 315         spin_unlock_irqrestore(&glink->tx_lock, flags);
 316
 317         return ret;
 318 }
 319
 320 static int qcom_glink_send_version(struct qcom_glink *glink)
 321 {
 322         struct glink_msg msg;
 323
 324         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 325         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 326         msg.param2 = cpu_to_le32(glink->features);
 327
 328         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 329 }
 330
 331 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 332 {
 333         struct glink_msg msg;
 334
 335         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 336         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 337         msg.param2 = cpu_to_le32(glink->features);
 338
 339         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 340 }
 341
 342 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 343                                      struct glink_channel *channel)
 344 {
 345         struct glink_msg msg;
 346
 347         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 348         msg.param1 = cpu_to_le16(channel->rcid);
 349         msg.param2 = cpu_to_le32(0);
 350
 351         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 352 }
 353
 354 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 355                                              unsigned int cid, bool granted)
 356 {
 357         struct glink_channel *channel;
 358         unsigned long flags;
 359
 360         spin_lock_irqsave(&glink->idr_lock, flags);
 361         channel = idr_find(&glink->rcids, cid);
 362         spin_unlock_irqrestore(&glink->idr_lock, flags);
 363         if (!channel) {
 364                 dev_err(glink->dev, "unable to find channel\n");
 365                 return;
 366         }
 367
 368         channel->intent_req_result = granted;
 369         complete(&channel->intent_req_comp);
 370 }
 371
 372 /**
 373  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 374  * @glink: Ptr to the glink edge
 375  * @channel: Ptr to the channel that the open req is sent
 376  *
 377  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 378  * Will return with refcount held, regardless of outcome.
 379  *
 380  * Returns 0 on success, negative errno otherwise.
 381  */
 382 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 383                                     struct glink_channel *channel)
 384 {
 385         struct {
 386                 struct glink_msg msg;
 387                 u8 name[GLINK_NAME_SIZE];
 388         } __packed req;
 389         int name_len = strlen(channel->name) + 1;
 390         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 391         int ret;
 392         unsigned long flags;
 393
 394         kref_get(&channel->refcount);
 395
 396         spin_lock_irqsave(&glink->idr_lock, flags);
 397         ret = idr_alloc_cyclic(&glink->lcids, channel,
 398                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 399                                GFP_ATOMIC);
 400         spin_unlock_irqrestore(&glink->idr_lock, flags);
 401         if (ret < 0)
 402                 return ret;
 403
 404         channel->lcid = ret;
 405
 406         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 407         req.msg.param1 = cpu_to_le16(channel->lcid);
 408         req.msg.param2 = cpu_to_le32(name_len);
 409         strcpy(req.name, channel->name);
 410
 411         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 412         if (ret)
 413                 goto remove_idr;
 414
 415         return 0;
 416
 417 remove_idr:
 418         spin_lock_irqsave(&glink->idr_lock, flags);
 419         idr_remove(&glink->lcids, channel->lcid);
 420         channel->lcid = 0;
 421         spin_unlock_irqrestore(&glink->idr_lock, flags);
 422
 423         return ret;
 424 }
 425
 426 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 427                                       struct glink_channel *channel)
 428 {
 429         struct glink_msg req;
 430
 431         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 432         req.param1 = cpu_to_le16(channel->lcid);
 433         req.param2 = 0;
 434
 435         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 436 }
 437
 438 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 439                                       unsigned int rcid)
 440 {
 441         struct glink_msg req;
 442
 443         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 444         req.param1 = cpu_to_le16(rcid);
 445         req.param2 = 0;
 446
 447         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 448 }
 449
 450 static void qcom_glink_rx_done_work(struct work_struct *work)
 451 {
 452         struct glink_channel *channel = container_of(work, struct glink_channel,
 453                                                      intent_work);
 454         struct qcom_glink *glink = channel->glink;
 455         struct glink_core_rx_intent *intent, *tmp;
 456         struct {
 457                 u16 id;
 458                 u16 lcid;
 459                 u32 liid;
 460         } __packed cmd;
 461
 462         unsigned int cid = channel->lcid;
 463         unsigned int iid;
 464         bool reuse;
 465         unsigned long flags;
 466
 467         spin_lock_irqsave(&channel->intent_lock, flags);
 468         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 469                 list_del(&intent->node);
 470                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 471                 iid = intent->id;
 472                 reuse = intent->reuse;
 473
 474                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 475                 cmd.lcid = cid;
 476                 cmd.liid = iid;
 477
 478                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 479                 if (!reuse) {
 480                         kfree(intent->data);
 481                         kfree(intent);
 482                 }
 483                 spin_lock_irqsave(&channel->intent_lock, flags);
 484         }
 485         spin_unlock_irqrestore(&channel->intent_lock, flags);
 486 }
 487
 488 static void qcom_glink_rx_done(struct qcom_glink *glink,
 489                                struct glink_channel *channel,
 490                                struct glink_core_rx_intent *intent)
 491 {
 492         /* We don't send RX_DONE to intentless systems */
 493         if (glink->intentless) {
 494                 kfree(intent->data);
 495                 kfree(intent);
 496                 return;
 497         }
 498
 499         /* Take it off the tree of receive intents */
 500         if (!intent->reuse) {
 501                 spin_lock(&channel->intent_lock);
 502                 idr_remove(&channel->liids, intent->id);
 503                 spin_unlock(&channel->intent_lock);
 504         }
 505
 506         /* Schedule the sending of a rx_done indication */
 507         spin_lock(&channel->intent_lock);
 508         list_add_tail(&intent->node, &channel->done_intents);
 509         spin_unlock(&channel->intent_lock);
 510
 511         schedule_work(&channel->intent_work);
 512 }
 513
 514 /**
 515  * qcom_glink_receive_version() - receive version/features from remote system
 516  *
 517  * @glink:      pointer to transport interface
 518  * @version:    remote version
 519  * @features:   remote features
 520  *
 521  * This function is called in response to a remote-initiated version/feature
 522  * negotiation sequence.
 523  */
 524 static void qcom_glink_receive_version(struct qcom_glink *glink,
 525                                        u32 version,
 526                                        u32 features)
 527 {
 528         switch (version) {
 529         case 0:
 530                 break;
 531         case GLINK_VERSION_1:
 532                 glink->features &= features;
 533                 /* FALLTHROUGH */
 534         default:
 535                 qcom_glink_send_version_ack(glink);
 536                 break;
 537         }
 538 }
 539
 540 /**
 541  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 542  *
 543  * @glink:      pointer to transport interface
 544  * @version:    remote version response
 545  * @features:   remote features response
 546  *
 547  * This function is called in response to a local-initiated version/feature
 548  * negotiation sequence and is the counter-offer from the remote side based
 549  * upon the initial version and feature set requested.
 550  */
 551 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 552                                            u32 version,
 553                                            u32 features)
 554 {
 555         switch (version) {
 556         case 0:
 557                 /* Version negotiation failed */
 558                 break;
 559         case GLINK_VERSION_1:
 560                 if (features == glink->features)
 561                         break;
 562
 563                 glink->features &= features;
 564                 /* FALLTHROUGH */
 565         default:
 566                 qcom_glink_send_version(glink);
 567                 break;
 568         }
 569 }
 570
 571 /**
 572  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 573  *      wire format and transmit
 574  * @glink:      The transport to transmit on.
 575  * @channel:    The glink channel
 576  * @granted:    The request response to encode.
 577  *
 578  * Return: 0 on success or standard Linux error code.
 579  */
 580 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 581                                           struct glink_channel *channel,
 582                                           bool granted)
 583 {
 584         struct glink_msg msg;
 585
 586         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 587         msg.param1 = cpu_to_le16(channel->lcid);
 588         msg.param2 = cpu_to_le32(granted);
 589
 590         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 591
 592         return 0;
 593 }
 594
 595 /**
 596  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 597  *                         transmit
 598  * @glink:      The transport to transmit on.
 599  * @channel:    The local channel
 600  * @intent:     The intent to pass on to remote.
 601  *
 602  * Return: 0 on success or standard Linux error code.
 603  */
 604 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 605                                        struct glink_channel *channel,
 606                                        struct glink_core_rx_intent *intent)
 607 {
 608         struct command {
 609                 __le16 id;
 610                 __le16 lcid;
 611                 __le32 count;
 612                 __le32 size;
 613                 __le32 liid;
 614         } __packed;
 615         struct command cmd;
 616
 617         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 618         cmd.lcid = cpu_to_le16(channel->lcid);
 619         cmd.count = cpu_to_le32(1);
 620         cmd.size = cpu_to_le32(intent->size);
 621         cmd.liid = cpu_to_le32(intent->id);
 622
 623         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 624
 625         return 0;
 626 }
 627
 628 static struct glink_core_rx_intent *
 629 qcom_glink_alloc_intent(struct qcom_glink *glink,
 630                         struct glink_channel *channel,
 631                         size_t size,
 632                         bool reuseable)
 633 {
 634         struct glink_core_rx_intent *intent;
 635         int ret;
 636         unsigned long flags;
 637
 638         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 639         if (!intent)
 640                 return NULL;
 641
 642         intent->data = kzalloc(size, GFP_KERNEL);
 643         if (!intent->data)
 644                 goto free_intent;
 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                 goto free_data;
 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 free_data:
 661         kfree(intent->data);
 662 free_intent:
 663         kfree(intent);
 664         return NULL;
 665 }
 666
 667 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 668                                       u32 cid, uint32_t iid,
 669                                       bool reuse)
 670 {
 671         struct glink_core_rx_intent *intent;
 672         struct glink_channel *channel;
 673         unsigned long flags;
 674
 675         spin_lock_irqsave(&glink->idr_lock, flags);
 676         channel = idr_find(&glink->rcids, cid);
 677         spin_unlock_irqrestore(&glink->idr_lock, flags);
 678         if (!channel) {
 679                 dev_err(glink->dev, "invalid channel id received\n");
 680                 return;
 681         }
 682
 683         spin_lock_irqsave(&channel->intent_lock, flags);
 684         intent = idr_find(&channel->riids, iid);
 685
 686         if (!intent) {
 687                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 688                 dev_err(glink->dev, "invalid intent id received\n");
 689                 return;
 690         }
 691
 692         intent->in_use = false;
 693
 694         if (!reuse) {
 695                 idr_remove(&channel->riids, intent->id);
 696                 kfree(intent);
 697         }
 698         spin_unlock_irqrestore(&channel->intent_lock, flags);
 699 }
 700
 701 /**
 702  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 703  *                                          from remote side
 704  * @glink:      Pointer to the transport interface
 705  * @cid:        Remote channel ID
 706  * @size:       size of the intent
 707  *
 708  * The function searches for the local channel to which the request for
 709  * rx_intent has arrived and allocates and notifies the remote back
 710  */
 711 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 712                                          u32 cid, size_t size)
 713 {
 714         struct glink_core_rx_intent *intent;
 715         struct glink_channel *channel;
 716         unsigned long flags;
 717
 718         spin_lock_irqsave(&glink->idr_lock, flags);
 719         channel = idr_find(&glink->rcids, cid);
 720         spin_unlock_irqrestore(&glink->idr_lock, flags);
 721
 722         if (!channel) {
 723                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 724                 return;
 725         }
 726
 727         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 728         if (intent)
 729                 qcom_glink_advertise_intent(glink, channel, intent);
 730
 731         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 732 }
 733
 734 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 735 {
 736         struct glink_defer_cmd *dcmd;
 737
 738         extra = ALIGN(extra, 8);
 739
 740         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 741                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 742                 return -ENXIO;
 743         }
 744
 745         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 746         if (!dcmd)
 747                 return -ENOMEM;
 748
 749         INIT_LIST_HEAD(&dcmd->node);
 750
 751         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 752
 753         spin_lock(&glink->rx_lock);
 754         list_add_tail(&dcmd->node, &glink->rx_queue);
 755         spin_unlock(&glink->rx_lock);
 756
 757         schedule_work(&glink->rx_work);
 758         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 759
 760         return 0;
 761 }
 762
 763 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 764 {
 765         struct glink_core_rx_intent *intent;
 766         struct glink_channel *channel;
 767         struct {
 768                 struct glink_msg msg;
 769                 __le32 chunk_size;
 770                 __le32 left_size;
 771         } __packed hdr;
 772         unsigned int chunk_size;
 773         unsigned int left_size;
 774         unsigned int rcid;
 775         unsigned int liid;
 776         int ret = 0;
 777         unsigned long flags;
 778
 779         if (avail < sizeof(hdr)) {
 780                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 781                 return -EAGAIN;
 782         }
 783
 784         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 785         chunk_size = le32_to_cpu(hdr.chunk_size);
 786         left_size = le32_to_cpu(hdr.left_size);
 787
 788         if (avail < sizeof(hdr) + chunk_size) {
 789                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 790                 return -EAGAIN;
 791         }
 792
 793         if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
 794                 return -EINVAL;
 795
 796         rcid = le16_to_cpu(hdr.msg.param1);
 797         spin_lock_irqsave(&glink->idr_lock, flags);
 798         channel = idr_find(&glink->rcids, rcid);
 799         spin_unlock_irqrestore(&glink->idr_lock, flags);
 800         if (!channel) {
 801                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 802
 803                 /* Drop the message */
 804                 goto advance_rx;
 805         }
 806
 807         if (glink->intentless) {
 808                 /* Might have an ongoing, fragmented, message to append */
 809                 if (!channel->buf) {
 810                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 811                         if (!intent)
 812                                 return -ENOMEM;
 813
 814                         intent->data = kmalloc(chunk_size + left_size,
 815                                                GFP_ATOMIC);
 816                         if (!intent->data) {
 817                                 kfree(intent);
 818                                 return -ENOMEM;
 819                         }
 820
 821                         intent->id = 0xbabababa;
 822                         intent->size = chunk_size + left_size;
 823                         intent->offset = 0;
 824
 825                         channel->buf = intent;
 826                 } else {
 827                         intent = channel->buf;
 828                 }
 829         } else {
 830                 liid = le32_to_cpu(hdr.msg.param2);
 831
 832                 spin_lock_irqsave(&channel->intent_lock, flags);
 833                 intent = idr_find(&channel->liids, liid);
 834                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 835
 836                 if (!intent) {
 837                         dev_err(glink->dev,
 838                                 "no intent found for channel %s intent %d",
 839                                 channel->name, liid);
 840                         goto advance_rx;
 841                 }
 842         }
 843
 844         if (intent->size - intent->offset < chunk_size) {
 845                 dev_err(glink->dev, "Insufficient space in intent\n");
 846
 847                 /* The packet header lied, drop payload */
 848                 goto advance_rx;
 849         }
 850
 851         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 852                            sizeof(hdr), chunk_size);
 853         intent->offset += chunk_size;
 854
 855         /* Handle message when no fragments remain to be received */
 856         if (!left_size) {
 857                 spin_lock(&channel->recv_lock);
 858                 if (channel->ept.cb) {
 859                         channel->ept.cb(channel->ept.rpdev,
 860                                         intent->data,
 861                                         intent->offset,
 862                                         channel->ept.priv,
 863                                         RPMSG_ADDR_ANY);
 864                 }
 865                 spin_unlock(&channel->recv_lock);
 866
 867                 intent->offset = 0;
 868                 channel->buf = NULL;
 869
 870                 qcom_glink_rx_done(glink, channel, intent);
 871         }
 872
 873 advance_rx:
 874         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 875
 876         return ret;
 877 }
 878
 879 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 880                                      unsigned int cid,
 881                                      unsigned int count,
 882                                      size_t avail)
 883 {
 884         struct glink_core_rx_intent *intent;
 885         struct glink_channel *channel;
 886         struct intent_pair {
 887                 __le32 size;
 888                 __le32 iid;
 889         };
 890
 891         struct {
 892                 struct glink_msg msg;
 893                 struct intent_pair intents[];
 894         } __packed * msg;
 895
 896         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
 897         int ret;
 898         int i;
 899         unsigned long flags;
 900
 901         if (avail < msglen) {
 902                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 903                 return;
 904         }
 905
 906         spin_lock_irqsave(&glink->idr_lock, flags);
 907         channel = idr_find(&glink->rcids, cid);
 908         spin_unlock_irqrestore(&glink->idr_lock, flags);
 909         if (!channel) {
 910                 dev_err(glink->dev, "intents for non-existing channel\n");
 911                 return;
 912         }
 913
 914         msg = kmalloc(msglen, GFP_ATOMIC);
 915         if (!msg)
 916                 return;
 917
 918         qcom_glink_rx_peak(glink, msg, 0, msglen);
 919
 920         for (i = 0; i < count; ++i) {
 921                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 922                 if (!intent)
 923                         break;
 924
 925                 intent->id = le32_to_cpu(msg->intents[i].iid);
 926                 intent->size = le32_to_cpu(msg->intents[i].size);
 927
 928                 spin_lock_irqsave(&channel->intent_lock, flags);
 929                 ret = idr_alloc(&channel->riids, intent,
 930                                 intent->id, intent->id + 1, GFP_ATOMIC);
 931                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 932
 933                 if (ret < 0)
 934                         dev_err(glink->dev, "failed to store remote intent\n");
 935         }
 936
 937         kfree(msg);
 938         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 939 }
 940
 941 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 942 {
 943         struct glink_channel *channel;
 944
 945         spin_lock(&glink->idr_lock);
 946         channel = idr_find(&glink->lcids, lcid);
 947         spin_unlock(&glink->idr_lock);
 948         if (!channel) {
 949                 dev_err(glink->dev, "Invalid open ack packet\n");
 950                 return -EINVAL;
 951         }
 952
 953         complete(&channel->open_ack);
 954
 955         return 0;
 956 }
 957
 958 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 959 {
 960         struct qcom_glink *glink = data;
 961         struct glink_msg msg;
 962         unsigned int param1;
 963         unsigned int param2;
 964         unsigned int avail;
 965         unsigned int cmd;
 966         int ret = 0;
 967
 968         for (;;) {
 969                 avail = qcom_glink_rx_avail(glink);
 970                 if (avail < sizeof(msg))
 971                         break;
 972
 973                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 974
 975                 cmd = le16_to_cpu(msg.cmd);
 976                 param1 = le16_to_cpu(msg.param1);
 977                 param2 = le32_to_cpu(msg.param2);
 978
 979                 switch (cmd) {
 980                 case RPM_CMD_VERSION:
 981                 case RPM_CMD_VERSION_ACK:
 982                 case RPM_CMD_CLOSE:
 983                 case RPM_CMD_CLOSE_ACK:
 984                 case RPM_CMD_RX_INTENT_REQ:
 985                         ret = qcom_glink_rx_defer(glink, 0);
 986                         break;
 987                 case RPM_CMD_OPEN_ACK:
 988                         ret = qcom_glink_rx_open_ack(glink, param1);
 989                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 990                         break;
 991                 case RPM_CMD_OPEN:
 992                         ret = qcom_glink_rx_defer(glink, param2);
 993                         break;
 994                 case RPM_CMD_TX_DATA:
 995                 case RPM_CMD_TX_DATA_CONT:
 996                         ret = qcom_glink_rx_data(glink, avail);
 997                         break;
 998                 case RPM_CMD_READ_NOTIF:
 999                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1000
1001                         mbox_send_message(glink->mbox_chan, NULL);
1002                         mbox_client_txdone(glink->mbox_chan, 0);
1003                         break;
1004                 case RPM_CMD_INTENT:
1005                         qcom_glink_handle_intent(glink, param1, param2, avail);
1006                         break;
1007                 case RPM_CMD_RX_DONE:
1008                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1009                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1010                         break;
1011                 case RPM_CMD_RX_DONE_W_REUSE:
1012                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1013                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1014                         break;
1015                 case RPM_CMD_RX_INTENT_REQ_ACK:
1016                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1017                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1018                         break;
1019                 default:
1020                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1021                         ret = -EINVAL;
1022                         break;
1023                 }
1024
1025                 if (ret)
1026                         break;
1027         }
1028
1029         return IRQ_HANDLED;
1030 }
1031
1032 /* Locally initiated rpmsg_create_ept */
1033 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1034                                                      const char *name)
1035 {
1036         struct glink_channel *channel;
1037         int ret;
1038         unsigned long flags;
1039
1040         channel = qcom_glink_alloc_channel(glink, name);
1041         if (IS_ERR(channel))
1042                 return ERR_CAST(channel);
1043
1044         ret = qcom_glink_send_open_req(glink, channel);
1045         if (ret)
1046                 goto release_channel;
1047
1048         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1049         if (!ret)
1050                 goto err_timeout;
1051
1052         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1053         if (!ret)
1054                 goto err_timeout;
1055
1056         qcom_glink_send_open_ack(glink, channel);
1057
1058         return channel;
1059
1060 err_timeout:
1061         /* qcom_glink_send_open_req() did register the channel in lcids*/
1062         spin_lock_irqsave(&glink->idr_lock, flags);
1063         idr_remove(&glink->lcids, channel->lcid);
1064         spin_unlock_irqrestore(&glink->idr_lock, flags);
1065
1066 release_channel:
1067         /* Release qcom_glink_send_open_req() reference */
1068         kref_put(&channel->refcount, qcom_glink_channel_release);
1069         /* Release qcom_glink_alloc_channel() reference */
1070         kref_put(&channel->refcount, qcom_glink_channel_release);
1071
1072         return ERR_PTR(-ETIMEDOUT);
1073 }
1074
1075 /* Remote initiated rpmsg_create_ept */
1076 static int qcom_glink_create_remote(struct qcom_glink *glink,
1077                                     struct glink_channel *channel)
1078 {
1079         int ret;
1080
1081         qcom_glink_send_open_ack(glink, channel);
1082
1083         ret = qcom_glink_send_open_req(glink, channel);
1084         if (ret)
1085                 goto close_link;
1086
1087         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1088         if (!ret) {
1089                 ret = -ETIMEDOUT;
1090                 goto close_link;
1091         }
1092
1093         return 0;
1094
1095 close_link:
1096         /*
1097          * Send a close request to "undo" our open-ack. The close-ack will
1098          * release the last reference.
1099          */
1100         qcom_glink_send_close_req(glink, channel);
1101
1102         /* Release qcom_glink_send_open_req() reference */
1103         kref_put(&channel->refcount, qcom_glink_channel_release);
1104
1105         return ret;
1106 }
1107
1108 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1109                                                     rpmsg_rx_cb_t cb,
1110                                                     void *priv,
1111                                                     struct rpmsg_channel_info
1112                                                                         chinfo)
1113 {
1114         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1115         struct glink_channel *channel;
1116         struct qcom_glink *glink = parent->glink;
1117         struct rpmsg_endpoint *ept;
1118         const char *name = chinfo.name;
1119         int cid;
1120         int ret;
1121         unsigned long flags;
1122
1123         spin_lock_irqsave(&glink->idr_lock, flags);
1124         idr_for_each_entry(&glink->rcids, channel, cid) {
1125                 if (!strcmp(channel->name, name))
1126                         break;
1127         }
1128         spin_unlock_irqrestore(&glink->idr_lock, flags);
1129
1130         if (!channel) {
1131                 channel = qcom_glink_create_local(glink, name);
1132                 if (IS_ERR(channel))
1133                         return NULL;
1134         } else {
1135                 ret = qcom_glink_create_remote(glink, channel);
1136                 if (ret)
1137                         return NULL;
1138         }
1139
1140         ept = &channel->ept;
1141         ept->rpdev = rpdev;
1142         ept->cb = cb;
1143         ept->priv = priv;
1144         ept->ops = &glink_endpoint_ops;
1145
1146         return ept;
1147 }
1148
1149 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1150 {
1151         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1152         struct device_node *np = rpdev->dev.of_node;
1153         struct qcom_glink *glink = channel->glink;
1154         struct glink_core_rx_intent *intent;
1155         const struct property *prop = NULL;
1156         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1157         int num_intents;
1158         int num_groups = 1;
1159         __be32 *val = defaults;
1160         int size;
1161
1162         if (glink->intentless)
1163                 return 0;
1164
1165         prop = of_find_property(np, "qcom,intents", NULL);
1166         if (prop) {
1167                 val = prop->value;
1168                 num_groups = prop->length / sizeof(u32) / 2;
1169         }
1170
1171         /* Channel is now open, advertise base set of intents */
1172         while (num_groups--) {
1173                 size = be32_to_cpup(val++);
1174                 num_intents = be32_to_cpup(val++);
1175                 while (num_intents--) {
1176                         intent = qcom_glink_alloc_intent(glink, channel, size,
1177                                                          true);
1178                         if (!intent)
1179                                 break;
1180
1181                         qcom_glink_advertise_intent(glink, channel, intent);
1182                 }
1183         }
1184         return 0;
1185 }
1186
1187 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1188 {
1189         struct glink_channel *channel = to_glink_channel(ept);
1190         struct qcom_glink *glink = channel->glink;
1191         unsigned long flags;
1192
1193         spin_lock_irqsave(&channel->recv_lock, flags);
1194         channel->ept.cb = NULL;
1195         spin_unlock_irqrestore(&channel->recv_lock, flags);
1196
1197         /* Decouple the potential rpdev from the channel */
1198         channel->rpdev = NULL;
1199
1200         qcom_glink_send_close_req(glink, channel);
1201 }
1202
1203 static int qcom_glink_request_intent(struct qcom_glink *glink,
1204                                      struct glink_channel *channel,
1205                                      size_t size)
1206 {
1207         struct {
1208                 u16 id;
1209                 u16 cid;
1210                 u32 size;
1211         } __packed cmd;
1212
1213         int ret;
1214
1215         mutex_lock(&channel->intent_req_lock);
1216
1217         reinit_completion(&channel->intent_req_comp);
1218
1219         cmd.id = RPM_CMD_RX_INTENT_REQ;
1220         cmd.cid = channel->lcid;
1221         cmd.size = size;
1222
1223         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1224         if (ret)
1225                 goto unlock;
1226
1227         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1228         if (!ret) {
1229                 dev_err(glink->dev, "intent request timed out\n");
1230                 ret = -ETIMEDOUT;
1231         } else {
1232                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1233         }
1234
1235 unlock:
1236         mutex_unlock(&channel->intent_req_lock);
1237         return ret;
1238 }
1239
1240 static int __qcom_glink_send(struct glink_channel *channel,
1241                              void *data, int len, bool wait)
1242 {
1243         struct qcom_glink *glink = channel->glink;
1244         struct glink_core_rx_intent *intent = NULL;
1245         struct glink_core_rx_intent *tmp;
1246         int iid = 0;
1247         struct {
1248                 struct glink_msg msg;
1249                 __le32 chunk_size;
1250                 __le32 left_size;
1251         } __packed req;
1252         int ret;
1253         unsigned long flags;
1254
1255         if (!glink->intentless) {
1256                 while (!intent) {
1257                         spin_lock_irqsave(&channel->intent_lock, flags);
1258                         idr_for_each_entry(&channel->riids, tmp, iid) {
1259                                 if (tmp->size >= len && !tmp->in_use) {
1260                                         if (!intent)
1261                                                 intent = tmp;
1262                                         else if (intent->size > tmp->size)
1263                                                 intent = tmp;
1264                                         if (intent->size == len)
1265                                                 break;
1266                                 }
1267                         }
1268                         if (intent)
1269                                 intent->in_use = true;
1270                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1271
1272                         /* We found an available intent */
1273                         if (intent)
1274                                 break;
1275
1276                         if (!wait)
1277                                 return -EBUSY;
1278
1279                         ret = qcom_glink_request_intent(glink, channel, len);
1280                         if (ret < 0)
1281                                 return ret;
1282                 }
1283
1284                 iid = intent->id;
1285         }
1286
1287         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1288         req.msg.param1 = cpu_to_le16(channel->lcid);
1289         req.msg.param2 = cpu_to_le32(iid);
1290         req.chunk_size = cpu_to_le32(len);
1291         req.left_size = cpu_to_le32(0);
1292
1293         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1294
1295         /* Mark intent available if we failed */
1296         if (ret && intent)
1297                 intent->in_use = false;
1298
1299         return ret;
1300 }
1301
1302 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1303 {
1304         struct glink_channel *channel = to_glink_channel(ept);
1305
1306         return __qcom_glink_send(channel, data, len, true);
1307 }
1308
1309 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1310 {
1311         struct glink_channel *channel = to_glink_channel(ept);
1312
1313         return __qcom_glink_send(channel, data, len, false);
1314 }
1315
1316 /*
1317  * Finds the device_node for the glink child interested in this channel.
1318  */
1319 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1320                                                     const char *channel)
1321 {
1322         struct device_node *child;
1323         const char *name;
1324         const char *key;
1325         int ret;
1326
1327         for_each_available_child_of_node(node, child) {
1328                 key = "qcom,glink-channels";
1329                 ret = of_property_read_string(child, key, &name);
1330                 if (ret)
1331                         continue;
1332
1333                 if (strcmp(name, channel) == 0)
1334                         return child;
1335         }
1336
1337         return NULL;
1338 }
1339
1340 static const struct rpmsg_device_ops glink_device_ops = {
1341         .create_ept = qcom_glink_create_ept,
1342         .announce_create = qcom_glink_announce_create,
1343 };
1344
1345 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1346         .destroy_ept = qcom_glink_destroy_ept,
1347         .send = qcom_glink_send,
1348         .trysend = qcom_glink_trysend,
1349 };
1350
1351 static void qcom_glink_rpdev_release(struct device *dev)
1352 {
1353         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1354         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1355
1356         channel->rpdev = NULL;
1357         kfree(rpdev);
1358 }
1359
1360 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1361                               char *name)
1362 {
1363         struct glink_channel *channel;
1364         struct rpmsg_device *rpdev;
1365         bool create_device = false;
1366         struct device_node *node;
1367         int lcid;
1368         int ret;
1369         unsigned long flags;
1370
1371         spin_lock_irqsave(&glink->idr_lock, flags);
1372         idr_for_each_entry(&glink->lcids, channel, lcid) {
1373                 if (!strcmp(channel->name, name))
1374                         break;
1375         }
1376         spin_unlock_irqrestore(&glink->idr_lock, flags);
1377
1378         if (!channel) {
1379                 channel = qcom_glink_alloc_channel(glink, name);
1380                 if (IS_ERR(channel))
1381                         return PTR_ERR(channel);
1382
1383                 /* The opening dance was initiated by the remote */
1384                 create_device = true;
1385         }
1386
1387         spin_lock_irqsave(&glink->idr_lock, flags);
1388         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1389         if (ret < 0) {
1390                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1391                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1392                 goto free_channel;
1393         }
1394         channel->rcid = ret;
1395         spin_unlock_irqrestore(&glink->idr_lock, flags);
1396
1397         complete(&channel->open_req);
1398
1399         if (create_device) {
1400                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1401                 if (!rpdev) {
1402                         ret = -ENOMEM;
1403                         goto rcid_remove;
1404                 }
1405
1406                 rpdev->ept = &channel->ept;
1407                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1408                 rpdev->src = RPMSG_ADDR_ANY;
1409                 rpdev->dst = RPMSG_ADDR_ANY;
1410                 rpdev->ops = &glink_device_ops;
1411
1412                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1413                 rpdev->dev.of_node = node;
1414                 rpdev->dev.parent = glink->dev;
1415                 rpdev->dev.release = qcom_glink_rpdev_release;
1416
1417                 ret = rpmsg_register_device(rpdev);
1418                 if (ret)
1419                         goto free_rpdev;
1420
1421                 channel->rpdev = rpdev;
1422         }
1423
1424         return 0;
1425
1426 free_rpdev:
1427         kfree(rpdev);
1428 rcid_remove:
1429         spin_lock_irqsave(&glink->idr_lock, flags);
1430         idr_remove(&glink->rcids, channel->rcid);
1431         channel->rcid = 0;
1432         spin_unlock_irqrestore(&glink->idr_lock, flags);
1433 free_channel:
1434         /* Release the reference, iff we took it */
1435         if (create_device)
1436                 kref_put(&channel->refcount, qcom_glink_channel_release);
1437
1438         return ret;
1439 }
1440
1441 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1442 {
1443         struct rpmsg_channel_info chinfo;
1444         struct glink_channel *channel;
1445         unsigned long flags;
1446
1447         spin_lock_irqsave(&glink->idr_lock, flags);
1448         channel = idr_find(&glink->rcids, rcid);
1449         spin_unlock_irqrestore(&glink->idr_lock, flags);
1450         if (WARN(!channel, "close request on unknown channel\n"))
1451                 return;
1452
1453         /* cancel pending rx_done work */
1454         cancel_work_sync(&channel->intent_work);
1455
1456         if (channel->rpdev) {
1457                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1458                 chinfo.src = RPMSG_ADDR_ANY;
1459                 chinfo.dst = RPMSG_ADDR_ANY;
1460
1461                 rpmsg_unregister_device(glink->dev, &chinfo);
1462         }
1463
1464         qcom_glink_send_close_ack(glink, channel->rcid);
1465
1466         spin_lock_irqsave(&glink->idr_lock, flags);
1467         idr_remove(&glink->rcids, channel->rcid);
1468         channel->rcid = 0;
1469         spin_unlock_irqrestore(&glink->idr_lock, flags);
1470
1471         kref_put(&channel->refcount, qcom_glink_channel_release);
1472 }
1473
1474 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1475 {
1476         struct glink_channel *channel;
1477         unsigned long flags;
1478
1479         spin_lock_irqsave(&glink->idr_lock, flags);
1480         channel = idr_find(&glink->lcids, lcid);
1481         if (WARN(!channel, "close ack on unknown channel\n")) {
1482                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1483                 return;
1484         }
1485
1486         idr_remove(&glink->lcids, channel->lcid);
1487         channel->lcid = 0;
1488         spin_unlock_irqrestore(&glink->idr_lock, flags);
1489
1490         kref_put(&channel->refcount, qcom_glink_channel_release);
1491 }
1492
1493 static void qcom_glink_work(struct work_struct *work)
1494 {
1495         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1496                                                 rx_work);
1497         struct glink_defer_cmd *dcmd;
1498         struct glink_msg *msg;
1499         unsigned long flags;
1500         unsigned int param1;
1501         unsigned int param2;
1502         unsigned int cmd;
1503
1504         for (;;) {
1505                 spin_lock_irqsave(&glink->rx_lock, flags);
1506                 if (list_empty(&glink->rx_queue)) {
1507                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1508                         break;
1509                 }
1510                 dcmd = list_first_entry(&glink->rx_queue,
1511                                         struct glink_defer_cmd, node);
1512                 list_del(&dcmd->node);
1513                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1514
1515                 msg = &dcmd->msg;
1516                 cmd = le16_to_cpu(msg->cmd);
1517                 param1 = le16_to_cpu(msg->param1);
1518                 param2 = le32_to_cpu(msg->param2);
1519
1520                 switch (cmd) {
1521                 case RPM_CMD_VERSION:
1522                         qcom_glink_receive_version(glink, param1, param2);
1523                         break;
1524                 case RPM_CMD_VERSION_ACK:
1525                         qcom_glink_receive_version_ack(glink, param1, param2);
1526                         break;
1527                 case RPM_CMD_OPEN:
1528                         qcom_glink_rx_open(glink, param1, msg->data);
1529                         break;
1530                 case RPM_CMD_CLOSE:
1531                         qcom_glink_rx_close(glink, param1);
1532                         break;
1533                 case RPM_CMD_CLOSE_ACK:
1534                         qcom_glink_rx_close_ack(glink, param1);
1535                         break;
1536                 case RPM_CMD_RX_INTENT_REQ:
1537                         qcom_glink_handle_intent_req(glink, param1, param2);
1538                         break;
1539                 default:
1540                         WARN(1, "Unknown defer object %d\n", cmd);
1541                         break;
1542                 }
1543
1544                 kfree(dcmd);
1545         }
1546 }
1547
1548 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1549                                            unsigned long features,
1550                                            struct qcom_glink_pipe *rx,
1551                                            struct qcom_glink_pipe *tx,
1552                                            bool intentless)
1553 {
1554         int irq;
1555         int ret;
1556         struct qcom_glink *glink;
1557
1558         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1559         if (!glink)
1560                 return ERR_PTR(-ENOMEM);
1561
1562         glink->dev = dev;
1563         glink->tx_pipe = tx;
1564         glink->rx_pipe = rx;
1565
1566         glink->features = features;
1567         glink->intentless = intentless;
1568
1569         spin_lock_init(&glink->tx_lock);
1570         spin_lock_init(&glink->rx_lock);
1571         INIT_LIST_HEAD(&glink->rx_queue);
1572         INIT_WORK(&glink->rx_work, qcom_glink_work);
1573
1574         spin_lock_init(&glink->idr_lock);
1575         idr_init(&glink->lcids);
1576         idr_init(&glink->rcids);
1577
1578         glink->mbox_client.dev = dev;
1579         glink->mbox_client.knows_txdone = true;
1580         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1581         if (IS_ERR(glink->mbox_chan)) {
1582                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1583                         dev_err(dev, "failed to acquire IPC channel\n");
1584                 return ERR_CAST(glink->mbox_chan);
1585         }
1586
1587         irq = of_irq_get(dev->of_node, 0);
1588         ret = devm_request_irq(dev, irq,
1589                                qcom_glink_native_intr,
1590                                IRQF_NO_SUSPEND | IRQF_SHARED,
1591                                "glink-native", glink);
1592         if (ret) {
1593                 dev_err(dev, "failed to request IRQ\n");
1594                 return ERR_PTR(ret);
1595         }
1596
1597         glink->irq = irq;
1598
1599         ret = qcom_glink_send_version(glink);
1600         if (ret)
1601                 return ERR_PTR(ret);
1602
1603         return glink;
1604 }
1605 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1606
1607 static int qcom_glink_remove_device(struct device *dev, void *data)
1608 {
1609         device_unregister(dev);
1610
1611         return 0;
1612 }
1613
1614 void qcom_glink_native_remove(struct qcom_glink *glink)
1615 {
1616         struct glink_channel *channel;
1617         int cid;
1618         int ret;
1619         unsigned long flags;
1620
1621         disable_irq(glink->irq);
1622         cancel_work_sync(&glink->rx_work);
1623
1624         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1625         if (ret)
1626                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1627
1628         spin_lock_irqsave(&glink->idr_lock, flags);
1629         /* Release any defunct local channels, waiting for close-ack */
1630         idr_for_each_entry(&glink->lcids, channel, cid)
1631                 kref_put(&channel->refcount, qcom_glink_channel_release);
1632
1633         idr_destroy(&glink->lcids);
1634         idr_destroy(&glink->rcids);
1635         spin_unlock_irqrestore(&glink->idr_lock, flags);
1636         mbox_free_channel(glink->mbox_chan);
1637 }
1638 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1639
1640 void qcom_glink_native_unregister(struct qcom_glink *glink)
1641 {
1642         device_unregister(glink->dev);
1643 }
1644 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1645
1646 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1647 MODULE_LICENSE("GPL v2");