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         mutex_init(&channel->intent_req_lock);
 225
 226         channel->glink = glink;
 227         channel->name = kstrdup(name, GFP_KERNEL);
 228
 229         init_completion(&channel->open_req);
 230         init_completion(&channel->open_ack);
 231         init_completion(&channel->intent_req_comp);
 232
 233         INIT_LIST_HEAD(&channel->done_intents);
 234         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 235
 236         idr_init(&channel->liids);
 237         idr_init(&channel->riids);
 238         kref_init(&channel->refcount);
 239
 240         return channel;
 241 }
 242
 243 static void qcom_glink_channel_release(struct kref *ref)
 244 {
 245         struct glink_channel *channel = container_of(ref, struct glink_channel,
 246                                                      refcount);
 247         struct glink_core_rx_intent *intent;
 248         struct glink_core_rx_intent *tmp;
 249         unsigned long flags;
 250         int iid;
 251
 252         /* cancel pending rx_done work */
 253         cancel_work_sync(&channel->intent_work);
 254
 255         spin_lock_irqsave(&channel->intent_lock, flags);
 256         /* Free all non-reuse intents pending rx_done work */
 257         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 258                 if (!intent->reuse) {
 259                         kfree(intent->data);
 260                         kfree(intent);
 261                 }
 262         }
 263
 264         idr_for_each_entry(&channel->liids, tmp, iid) {
 265                 kfree(tmp->data);
 266                 kfree(tmp);
 267         }
 268         idr_destroy(&channel->liids);
 269
 270         idr_for_each_entry(&channel->riids, tmp, iid)
 271                 kfree(tmp);
 272         idr_destroy(&channel->riids);
 273         spin_unlock_irqrestore(&channel->intent_lock, flags);
 274
 275         kfree(channel->name);
 276         kfree(channel);
 277 }
 278
 279 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 280 {
 281         return glink->rx_pipe->avail(glink->rx_pipe);
 282 }
 283
 284 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 285                                void *data, unsigned int offset, size_t count)
 286 {
 287         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 288 }
 289
 290 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 291 {
 292         glink->rx_pipe->advance(glink->rx_pipe, count);
 293 }
 294
 295 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 296 {
 297         return glink->tx_pipe->avail(glink->tx_pipe);
 298 }
 299
 300 static void qcom_glink_tx_write(struct qcom_glink *glink,
 301                                 const void *hdr, size_t hlen,
 302                                 const void *data, size_t dlen)
 303 {
 304         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 305 }
 306
 307 static int qcom_glink_tx(struct qcom_glink *glink,
 308                          const void *hdr, size_t hlen,
 309                          const void *data, size_t dlen, bool wait)
 310 {
 311         unsigned int tlen = hlen + dlen;
 312         int ret;
 313
 314         /* Reject packets that are too big */
 315         if (tlen >= glink->tx_pipe->length)
 316                 return -EINVAL;
 317
 318         ret = mutex_lock_interruptible(&glink->tx_lock);
 319         if (ret)
 320                 return ret;
 321
 322         while (qcom_glink_tx_avail(glink) < tlen) {
 323                 if (!wait) {
 324                         ret = -EAGAIN;
 325                         goto out;
 326                 }
 327
 328                 usleep_range(10000, 15000);
 329         }
 330
 331         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 332
 333         mbox_send_message(glink->mbox_chan, NULL);
 334         mbox_client_txdone(glink->mbox_chan, 0);
 335
 336 out:
 337         mutex_unlock(&glink->tx_lock);
 338
 339         return ret;
 340 }
 341
 342 static int qcom_glink_send_version(struct qcom_glink *glink)
 343 {
 344         struct glink_msg msg;
 345
 346         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 347         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 348         msg.param2 = cpu_to_le32(glink->features);
 349
 350         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 351 }
 352
 353 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 354 {
 355         struct glink_msg msg;
 356
 357         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 358         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 359         msg.param2 = cpu_to_le32(glink->features);
 360
 361         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 362 }
 363
 364 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 365                                      struct glink_channel *channel)
 366 {
 367         struct glink_msg msg;
 368
 369         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 370         msg.param1 = cpu_to_le16(channel->rcid);
 371         msg.param2 = cpu_to_le32(0);
 372
 373         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 374 }
 375
 376 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 377                                              unsigned int cid, bool granted)
 378 {
 379         struct glink_channel *channel;
 380         unsigned long flags;
 381
 382         spin_lock_irqsave(&glink->idr_lock, flags);
 383         channel = idr_find(&glink->rcids, cid);
 384         spin_unlock_irqrestore(&glink->idr_lock, flags);
 385         if (!channel) {
 386                 dev_err(glink->dev, "unable to find channel\n");
 387                 return;
 388         }
 389
 390         channel->intent_req_result = granted;
 391         complete(&channel->intent_req_comp);
 392 }
 393
 394 /**
 395  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 396  * @glink: Ptr to the glink edge
 397  * @channel: Ptr to the channel that the open req is sent
 398  *
 399  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 400  * Will return with refcount held, regardless of outcome.
 401  *
 402  * Returns 0 on success, negative errno otherwise.
 403  */
 404 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 405                                     struct glink_channel *channel)
 406 {
 407         struct {
 408                 struct glink_msg msg;
 409                 u8 name[GLINK_NAME_SIZE];
 410         } __packed req;
 411         int name_len = strlen(channel->name) + 1;
 412         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 413         int ret;
 414         unsigned long flags;
 415
 416         kref_get(&channel->refcount);
 417
 418         spin_lock_irqsave(&glink->idr_lock, flags);
 419         ret = idr_alloc_cyclic(&glink->lcids, channel,
 420                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 421                                GFP_ATOMIC);
 422         spin_unlock_irqrestore(&glink->idr_lock, flags);
 423         if (ret < 0)
 424                 return ret;
 425
 426         channel->lcid = ret;
 427
 428         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 429         req.msg.param1 = cpu_to_le16(channel->lcid);
 430         req.msg.param2 = cpu_to_le32(name_len);
 431         strcpy(req.name, channel->name);
 432
 433         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 434         if (ret)
 435                 goto remove_idr;
 436
 437         return 0;
 438
 439 remove_idr:
 440         spin_lock_irqsave(&glink->idr_lock, flags);
 441         idr_remove(&glink->lcids, channel->lcid);
 442         channel->lcid = 0;
 443         spin_unlock_irqrestore(&glink->idr_lock, flags);
 444
 445         return ret;
 446 }
 447
 448 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 449                                       struct glink_channel *channel)
 450 {
 451         struct glink_msg req;
 452
 453         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 454         req.param1 = cpu_to_le16(channel->lcid);
 455         req.param2 = 0;
 456
 457         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 458 }
 459
 460 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 461                                       unsigned int rcid)
 462 {
 463         struct glink_msg req;
 464
 465         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 466         req.param1 = cpu_to_le16(rcid);
 467         req.param2 = 0;
 468
 469         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 470 }
 471
 472 static void qcom_glink_rx_done_work(struct work_struct *work)
 473 {
 474         struct glink_channel *channel = container_of(work, struct glink_channel,
 475                                                      intent_work);
 476         struct qcom_glink *glink = channel->glink;
 477         struct glink_core_rx_intent *intent, *tmp;
 478         struct {
 479                 u16 id;
 480                 u16 lcid;
 481                 u32 liid;
 482         } __packed cmd;
 483
 484         unsigned int cid = channel->lcid;
 485         unsigned int iid;
 486         bool reuse;
 487         unsigned long flags;
 488
 489         spin_lock_irqsave(&channel->intent_lock, flags);
 490         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 491                 list_del(&intent->node);
 492                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 493                 iid = intent->id;
 494                 reuse = intent->reuse;
 495
 496                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 497                 cmd.lcid = cid;
 498                 cmd.liid = iid;
 499
 500                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 501                 if (!reuse) {
 502                         kfree(intent->data);
 503                         kfree(intent);
 504                 }
 505                 spin_lock_irqsave(&channel->intent_lock, flags);
 506         }
 507         spin_unlock_irqrestore(&channel->intent_lock, flags);
 508 }
 509
 510 static void qcom_glink_rx_done(struct qcom_glink *glink,
 511                                struct glink_channel *channel,
 512                                struct glink_core_rx_intent *intent)
 513 {
 514         /* We don't send RX_DONE to intentless systems */
 515         if (glink->intentless) {
 516                 kfree(intent->data);
 517                 kfree(intent);
 518                 return;
 519         }
 520
 521         /* Take it off the tree of receive intents */
 522         if (!intent->reuse) {
 523                 spin_lock(&channel->intent_lock);
 524                 idr_remove(&channel->liids, intent->id);
 525                 spin_unlock(&channel->intent_lock);
 526         }
 527
 528         /* Schedule the sending of a rx_done indication */
 529         spin_lock(&channel->intent_lock);
 530         list_add_tail(&intent->node, &channel->done_intents);
 531         spin_unlock(&channel->intent_lock);
 532
 533         schedule_work(&channel->intent_work);
 534 }
 535
 536 /**
 537  * qcom_glink_receive_version() - receive version/features from remote system
 538  *
 539  * @glink:      pointer to transport interface
 540  * @r_version:  remote version
 541  * @r_features: remote features
 542  *
 543  * This function is called in response to a remote-initiated version/feature
 544  * negotiation sequence.
 545  */
 546 static void qcom_glink_receive_version(struct qcom_glink *glink,
 547                                        u32 version,
 548                                        u32 features)
 549 {
 550         switch (version) {
 551         case 0:
 552                 break;
 553         case GLINK_VERSION_1:
 554                 glink->features &= features;
 555                 /* FALLTHROUGH */
 556         default:
 557                 qcom_glink_send_version_ack(glink);
 558                 break;
 559         }
 560 }
 561
 562 /**
 563  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 564  *
 565  * @glink:      pointer to transport interface
 566  * @r_version:  remote version response
 567  * @r_features: remote features response
 568  *
 569  * This function is called in response to a local-initiated version/feature
 570  * negotiation sequence and is the counter-offer from the remote side based
 571  * upon the initial version and feature set requested.
 572  */
 573 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 574                                            u32 version,
 575                                            u32 features)
 576 {
 577         switch (version) {
 578         case 0:
 579                 /* Version negotiation failed */
 580                 break;
 581         case GLINK_VERSION_1:
 582                 if (features == glink->features)
 583                         break;
 584
 585                 glink->features &= features;
 586                 /* FALLTHROUGH */
 587         default:
 588                 qcom_glink_send_version(glink);
 589                 break;
 590         }
 591 }
 592
 593 /**
 594  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 595                                       wire format and transmit
 596  * @glink:      The transport to transmit on.
 597  * @channel:    The glink channel
 598  * @granted:    The request response to encode.
 599  *
 600  * Return: 0 on success or standard Linux error code.
 601  */
 602 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 603                                           struct glink_channel *channel,
 604                                           bool granted)
 605 {
 606         struct glink_msg msg;
 607
 608         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 609         msg.param1 = cpu_to_le16(channel->lcid);
 610         msg.param2 = cpu_to_le32(granted);
 611
 612         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 613
 614         return 0;
 615 }
 616
 617 /**
 618  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 619  *                         transmit
 620  * @glink:      The transport to transmit on.
 621  * @channel:    The local channel
 622  * @size:       The intent to pass on to remote.
 623  *
 624  * Return: 0 on success or standard Linux error code.
 625  */
 626 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 627                                        struct glink_channel *channel,
 628                                        struct glink_core_rx_intent *intent)
 629 {
 630         struct command {
 631                 u16 id;
 632                 u16 lcid;
 633                 u32 count;
 634                 u32 size;
 635                 u32 liid;
 636         } __packed;
 637         struct command cmd;
 638
 639         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 640         cmd.lcid = cpu_to_le16(channel->lcid);
 641         cmd.count = cpu_to_le32(1);
 642         cmd.size = cpu_to_le32(intent->size);
 643         cmd.liid = cpu_to_le32(intent->id);
 644
 645         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 646
 647         return 0;
 648 }
 649
 650 static struct glink_core_rx_intent *
 651 qcom_glink_alloc_intent(struct qcom_glink *glink,
 652                         struct glink_channel *channel,
 653                         size_t size,
 654                         bool reuseable)
 655 {
 656         struct glink_core_rx_intent *intent;
 657         int ret;
 658         unsigned long flags;
 659
 660         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 661         if (!intent)
 662                 return NULL;
 663
 664         intent->data = kzalloc(size, GFP_KERNEL);
 665         if (!intent->data)
 666                 goto free_intent;
 667
 668         spin_lock_irqsave(&channel->intent_lock, flags);
 669         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 670         if (ret < 0) {
 671                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 672                 goto free_data;
 673         }
 674         spin_unlock_irqrestore(&channel->intent_lock, flags);
 675
 676         intent->id = ret;
 677         intent->size = size;
 678         intent->reuse = reuseable;
 679
 680         return intent;
 681
 682 free_data:
 683         kfree(intent->data);
 684 free_intent:
 685         kfree(intent);
 686         return NULL;
 687 }
 688
 689 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 690                                       u32 cid, uint32_t iid,
 691                                       bool reuse)
 692 {
 693         struct glink_core_rx_intent *intent;
 694         struct glink_channel *channel;
 695         unsigned long flags;
 696
 697         spin_lock_irqsave(&glink->idr_lock, flags);
 698         channel = idr_find(&glink->rcids, cid);
 699         spin_unlock_irqrestore(&glink->idr_lock, flags);
 700         if (!channel) {
 701                 dev_err(glink->dev, "invalid channel id received\n");
 702                 return;
 703         }
 704
 705         spin_lock_irqsave(&channel->intent_lock, flags);
 706         intent = idr_find(&channel->riids, iid);
 707
 708         if (!intent) {
 709                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 710                 dev_err(glink->dev, "invalid intent id received\n");
 711                 return;
 712         }
 713
 714         intent->in_use = false;
 715
 716         if (!reuse) {
 717                 idr_remove(&channel->riids, intent->id);
 718                 kfree(intent);
 719         }
 720         spin_unlock_irqrestore(&channel->intent_lock, flags);
 721 }
 722
 723 /**
 724  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 725  *                                          from remote side
 726  * if_ptr:      Pointer to the transport interface
 727  * rcid:        Remote channel ID
 728  * size:        size of the intent
 729  *
 730  * The function searches for the local channel to which the request for
 731  * rx_intent has arrived and allocates and notifies the remote back
 732  */
 733 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 734                                          u32 cid, size_t size)
 735 {
 736         struct glink_core_rx_intent *intent;
 737         struct glink_channel *channel;
 738         unsigned long flags;
 739
 740         spin_lock_irqsave(&glink->idr_lock, flags);
 741         channel = idr_find(&glink->rcids, cid);
 742         spin_unlock_irqrestore(&glink->idr_lock, flags);
 743
 744         if (!channel) {
 745                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 746                 return;
 747         }
 748
 749         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 750         if (intent)
 751                 qcom_glink_advertise_intent(glink, channel, intent);
 752
 753         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 754 }
 755
 756 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 757 {
 758         struct glink_defer_cmd *dcmd;
 759
 760         extra = ALIGN(extra, 8);
 761
 762         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 763                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 764                 return -ENXIO;
 765         }
 766
 767         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 768         if (!dcmd)
 769                 return -ENOMEM;
 770
 771         INIT_LIST_HEAD(&dcmd->node);
 772
 773         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 774
 775         spin_lock(&glink->rx_lock);
 776         list_add_tail(&dcmd->node, &glink->rx_queue);
 777         spin_unlock(&glink->rx_lock);
 778
 779         schedule_work(&glink->rx_work);
 780         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 781
 782         return 0;
 783 }
 784
 785 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 786 {
 787         struct glink_core_rx_intent *intent;
 788         struct glink_channel *channel;
 789         struct {
 790                 struct glink_msg msg;
 791                 __le32 chunk_size;
 792                 __le32 left_size;
 793         } __packed hdr;
 794         unsigned int chunk_size;
 795         unsigned int left_size;
 796         unsigned int rcid;
 797         unsigned int liid;
 798         int ret = 0;
 799         unsigned long flags;
 800
 801         if (avail < sizeof(hdr)) {
 802                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 803                 return -EAGAIN;
 804         }
 805
 806         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 807         chunk_size = le32_to_cpu(hdr.chunk_size);
 808         left_size = le32_to_cpu(hdr.left_size);
 809
 810         if (avail < sizeof(hdr) + chunk_size) {
 811                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 812                 return -EAGAIN;
 813         }
 814
 815         rcid = le16_to_cpu(hdr.msg.param1);
 816         spin_lock_irqsave(&glink->idr_lock, flags);
 817         channel = idr_find(&glink->rcids, rcid);
 818         spin_unlock_irqrestore(&glink->idr_lock, flags);
 819         if (!channel) {
 820                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 821
 822                 /* Drop the message */
 823                 goto advance_rx;
 824         }
 825
 826         if (glink->intentless) {
 827                 /* Might have an ongoing, fragmented, message to append */
 828                 if (!channel->buf) {
 829                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 830                         if (!intent)
 831                                 return -ENOMEM;
 832
 833                         intent->data = kmalloc(chunk_size + left_size,
 834                                                GFP_ATOMIC);
 835                         if (!intent->data) {
 836                                 kfree(intent);
 837                                 return -ENOMEM;
 838                         }
 839
 840                         intent->id = 0xbabababa;
 841                         intent->size = chunk_size + left_size;
 842                         intent->offset = 0;
 843
 844                         channel->buf = intent;
 845                 } else {
 846                         intent = channel->buf;
 847                 }
 848         } else {
 849                 liid = le32_to_cpu(hdr.msg.param2);
 850
 851                 spin_lock_irqsave(&channel->intent_lock, flags);
 852                 intent = idr_find(&channel->liids, liid);
 853                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 854
 855                 if (!intent) {
 856                         dev_err(glink->dev,
 857                                 "no intent found for channel %s intent %d",
 858                                 channel->name, liid);
 859                         ret = -ENOENT;
 860                         goto advance_rx;
 861                 }
 862         }
 863
 864         if (intent->size - intent->offset < chunk_size) {
 865                 dev_err(glink->dev, "Insufficient space in intent\n");
 866
 867                 /* The packet header lied, drop payload */
 868                 goto advance_rx;
 869         }
 870
 871         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 872                            sizeof(hdr), chunk_size);
 873         intent->offset += chunk_size;
 874
 875         /* Handle message when no fragments remain to be received */
 876         if (!left_size) {
 877                 spin_lock(&channel->recv_lock);
 878                 if (channel->ept.cb) {
 879                         channel->ept.cb(channel->ept.rpdev,
 880                                         intent->data,
 881                                         intent->offset,
 882                                         channel->ept.priv,
 883                                         RPMSG_ADDR_ANY);
 884                 }
 885                 spin_unlock(&channel->recv_lock);
 886
 887                 intent->offset = 0;
 888                 channel->buf = NULL;
 889
 890                 qcom_glink_rx_done(glink, channel, intent);
 891         }
 892
 893 advance_rx:
 894         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 895
 896         return ret;
 897 }
 898
 899 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 900                                      unsigned int cid,
 901                                      unsigned int count,
 902                                      size_t avail)
 903 {
 904         struct glink_core_rx_intent *intent;
 905         struct glink_channel *channel;
 906         struct intent_pair {
 907                 __le32 size;
 908                 __le32 iid;
 909         };
 910
 911         struct {
 912                 struct glink_msg msg;
 913                 struct intent_pair intents[];
 914         } __packed * msg;
 915
 916         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
 917         int ret;
 918         int i;
 919         unsigned long flags;
 920
 921         if (avail < msglen) {
 922                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 923                 return;
 924         }
 925
 926         spin_lock_irqsave(&glink->idr_lock, flags);
 927         channel = idr_find(&glink->rcids, cid);
 928         spin_unlock_irqrestore(&glink->idr_lock, flags);
 929         if (!channel) {
 930                 dev_err(glink->dev, "intents for non-existing channel\n");
 931                 qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 932                 return;
 933         }
 934
 935         msg = kmalloc(msglen, GFP_ATOMIC);
 936         if (!msg)
 937                 return;
 938
 939         qcom_glink_rx_peak(glink, msg, 0, msglen);
 940
 941         for (i = 0; i < count; ++i) {
 942                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 943                 if (!intent)
 944                         break;
 945
 946                 intent->id = le32_to_cpu(msg->intents[i].iid);
 947                 intent->size = le32_to_cpu(msg->intents[i].size);
 948
 949                 spin_lock_irqsave(&channel->intent_lock, flags);
 950                 ret = idr_alloc(&channel->riids, intent,
 951                                 intent->id, intent->id + 1, GFP_ATOMIC);
 952                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 953
 954                 if (ret < 0)
 955                         dev_err(glink->dev, "failed to store remote intent\n");
 956         }
 957
 958         kfree(msg);
 959         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 960 }
 961
 962 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 963 {
 964         struct glink_channel *channel;
 965
 966         spin_lock(&glink->idr_lock);
 967         channel = idr_find(&glink->lcids, lcid);
 968         spin_unlock(&glink->idr_lock);
 969         if (!channel) {
 970                 dev_err(glink->dev, "Invalid open ack packet\n");
 971                 return -EINVAL;
 972         }
 973
 974         complete(&channel->open_ack);
 975
 976         return 0;
 977 }
 978
 979 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 980 {
 981         struct qcom_glink *glink = data;
 982         struct glink_msg msg;
 983         unsigned int param1;
 984         unsigned int param2;
 985         unsigned int avail;
 986         unsigned int cmd;
 987         int ret = 0;
 988
 989         for (;;) {
 990                 avail = qcom_glink_rx_avail(glink);
 991                 if (avail < sizeof(msg))
 992                         break;
 993
 994                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 995
 996                 cmd = le16_to_cpu(msg.cmd);
 997                 param1 = le16_to_cpu(msg.param1);
 998                 param2 = le32_to_cpu(msg.param2);
 999
1000                 switch (cmd) {
1001                 case RPM_CMD_VERSION:
1002                 case RPM_CMD_VERSION_ACK:
1003                 case RPM_CMD_CLOSE:
1004                 case RPM_CMD_CLOSE_ACK:
1005                 case RPM_CMD_RX_INTENT_REQ:
1006                         ret = qcom_glink_rx_defer(glink, 0);
1007                         break;
1008                 case RPM_CMD_OPEN_ACK:
1009                         ret = qcom_glink_rx_open_ack(glink, param1);
1010                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1011                         break;
1012                 case RPM_CMD_OPEN:
1013                         ret = qcom_glink_rx_defer(glink, param2);
1014                         break;
1015                 case RPM_CMD_TX_DATA:
1016                 case RPM_CMD_TX_DATA_CONT:
1017                         ret = qcom_glink_rx_data(glink, avail);
1018                         break;
1019                 case RPM_CMD_READ_NOTIF:
1020                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1021
1022                         mbox_send_message(glink->mbox_chan, NULL);
1023                         mbox_client_txdone(glink->mbox_chan, 0);
1024                         break;
1025                 case RPM_CMD_INTENT:
1026                         qcom_glink_handle_intent(glink, param1, param2, avail);
1027                         break;
1028                 case RPM_CMD_RX_DONE:
1029                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1030                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1031                         break;
1032                 case RPM_CMD_RX_DONE_W_REUSE:
1033                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1034                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1035                         break;
1036                 case RPM_CMD_RX_INTENT_REQ_ACK:
1037                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1038                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1039                         break;
1040                 default:
1041                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1042                         ret = -EINVAL;
1043                         break;
1044                 }
1045
1046                 if (ret)
1047                         break;
1048         }
1049
1050         return IRQ_HANDLED;
1051 }
1052
1053 /* Locally initiated rpmsg_create_ept */
1054 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1055                                                      const char *name)
1056 {
1057         struct glink_channel *channel;
1058         int ret;
1059         unsigned long flags;
1060
1061         channel = qcom_glink_alloc_channel(glink, name);
1062         if (IS_ERR(channel))
1063                 return ERR_CAST(channel);
1064
1065         ret = qcom_glink_send_open_req(glink, channel);
1066         if (ret)
1067                 goto release_channel;
1068
1069         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1070         if (!ret)
1071                 goto err_timeout;
1072
1073         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1074         if (!ret)
1075                 goto err_timeout;
1076
1077         qcom_glink_send_open_ack(glink, channel);
1078
1079         return channel;
1080
1081 err_timeout:
1082         /* qcom_glink_send_open_req() did register the channel in lcids*/
1083         spin_lock_irqsave(&glink->idr_lock, flags);
1084         idr_remove(&glink->lcids, channel->lcid);
1085         spin_unlock_irqrestore(&glink->idr_lock, flags);
1086
1087 release_channel:
1088         /* Release qcom_glink_send_open_req() reference */
1089         kref_put(&channel->refcount, qcom_glink_channel_release);
1090         /* Release qcom_glink_alloc_channel() reference */
1091         kref_put(&channel->refcount, qcom_glink_channel_release);
1092
1093         return ERR_PTR(-ETIMEDOUT);
1094 }
1095
1096 /* Remote initiated rpmsg_create_ept */
1097 static int qcom_glink_create_remote(struct qcom_glink *glink,
1098                                     struct glink_channel *channel)
1099 {
1100         int ret;
1101
1102         qcom_glink_send_open_ack(glink, channel);
1103
1104         ret = qcom_glink_send_open_req(glink, channel);
1105         if (ret)
1106                 goto close_link;
1107
1108         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1109         if (!ret) {
1110                 ret = -ETIMEDOUT;
1111                 goto close_link;
1112         }
1113
1114         return 0;
1115
1116 close_link:
1117         /*
1118          * Send a close request to "undo" our open-ack. The close-ack will
1119          * release qcom_glink_send_open_req() reference and the last reference
1120          * will be relesed after receiving remote_close or transport unregister
1121          * by calling qcom_glink_native_remove().
1122          */
1123         qcom_glink_send_close_req(glink, channel);
1124
1125         return ret;
1126 }
1127
1128 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1129                                                     rpmsg_rx_cb_t cb,
1130                                                     void *priv,
1131                                                     struct rpmsg_channel_info
1132                                                                         chinfo)
1133 {
1134         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1135         struct glink_channel *channel;
1136         struct qcom_glink *glink = parent->glink;
1137         struct rpmsg_endpoint *ept;
1138         const char *name = chinfo.name;
1139         int cid;
1140         int ret;
1141         unsigned long flags;
1142
1143         spin_lock_irqsave(&glink->idr_lock, flags);
1144         idr_for_each_entry(&glink->rcids, channel, cid) {
1145                 if (!strcmp(channel->name, name))
1146                         break;
1147         }
1148         spin_unlock_irqrestore(&glink->idr_lock, flags);
1149
1150         if (!channel) {
1151                 channel = qcom_glink_create_local(glink, name);
1152                 if (IS_ERR(channel))
1153                         return NULL;
1154         } else {
1155                 ret = qcom_glink_create_remote(glink, channel);
1156                 if (ret)
1157                         return NULL;
1158         }
1159
1160         ept = &channel->ept;
1161         ept->rpdev = rpdev;
1162         ept->cb = cb;
1163         ept->priv = priv;
1164         ept->ops = &glink_endpoint_ops;
1165
1166         return ept;
1167 }
1168
1169 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1170 {
1171         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1172         struct glink_core_rx_intent *intent;
1173         struct qcom_glink *glink = channel->glink;
1174         int num_intents = glink->intentless ? 0 : 5;
1175
1176         /* Channel is now open, advertise base set of intents */
1177         while (num_intents--) {
1178                 intent = qcom_glink_alloc_intent(glink, channel, SZ_1K, true);
1179                 if (!intent)
1180                         break;
1181
1182                 qcom_glink_advertise_intent(glink, channel, intent);
1183         }
1184
1185         return 0;
1186 }
1187
1188 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1189 {
1190         struct glink_channel *channel = to_glink_channel(ept);
1191         struct qcom_glink *glink = channel->glink;
1192         unsigned long flags;
1193
1194         spin_lock_irqsave(&channel->recv_lock, flags);
1195         channel->ept.cb = NULL;
1196         spin_unlock_irqrestore(&channel->recv_lock, flags);
1197
1198         /* Decouple the potential rpdev from the channel */
1199         channel->rpdev = NULL;
1200
1201         qcom_glink_send_close_req(glink, channel);
1202 }
1203
1204 static int qcom_glink_request_intent(struct qcom_glink *glink,
1205                                      struct glink_channel *channel,
1206                                      size_t size)
1207 {
1208         struct {
1209                 u16 id;
1210                 u16 cid;
1211                 u32 size;
1212         } __packed cmd;
1213
1214         int ret;
1215
1216         mutex_lock(&channel->intent_req_lock);
1217
1218         reinit_completion(&channel->intent_req_comp);
1219
1220         cmd.id = RPM_CMD_RX_INTENT_REQ;
1221         cmd.cid = channel->lcid;
1222         cmd.size = size;
1223
1224         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1225         if (ret)
1226                 goto unlock;
1227
1228         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1229         if (!ret) {
1230                 dev_err(glink->dev, "intent request timed out\n");
1231                 ret = -ETIMEDOUT;
1232         } else {
1233                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1234         }
1235
1236 unlock:
1237         mutex_unlock(&channel->intent_req_lock);
1238         return ret;
1239 }
1240
1241 static int __qcom_glink_send(struct glink_channel *channel,
1242                              void *data, int len, bool wait)
1243 {
1244         struct qcom_glink *glink = channel->glink;
1245         struct glink_core_rx_intent *intent = NULL;
1246         struct glink_core_rx_intent *tmp;
1247         int iid = 0;
1248         struct {
1249                 struct glink_msg msg;
1250                 __le32 chunk_size;
1251                 __le32 left_size;
1252         } __packed req;
1253         int ret;
1254         unsigned long flags;
1255
1256         if (!glink->intentless) {
1257                 while (!intent) {
1258                         spin_lock_irqsave(&channel->intent_lock, flags);
1259                         idr_for_each_entry(&channel->riids, tmp, iid) {
1260                                 if (tmp->size >= len && !tmp->in_use) {
1261                                         tmp->in_use = true;
1262                                         intent = tmp;
1263                                         break;
1264                                 }
1265                         }
1266                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1267
1268                         /* We found an available intent */
1269                         if (intent)
1270                                 break;
1271
1272                         if (!wait)
1273                                 return -EBUSY;
1274
1275                         ret = qcom_glink_request_intent(glink, channel, len);
1276                         if (ret < 0)
1277                                 return ret;
1278                 }
1279
1280                 iid = intent->id;
1281         }
1282
1283         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1284         req.msg.param1 = cpu_to_le16(channel->lcid);
1285         req.msg.param2 = cpu_to_le32(iid);
1286         req.chunk_size = cpu_to_le32(len);
1287         req.left_size = cpu_to_le32(0);
1288
1289         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1290
1291         /* Mark intent available if we failed */
1292         if (ret && intent)
1293                 intent->in_use = false;
1294
1295         return ret;
1296 }
1297
1298 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1299 {
1300         struct glink_channel *channel = to_glink_channel(ept);
1301
1302         return __qcom_glink_send(channel, data, len, true);
1303 }
1304
1305 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1306 {
1307         struct glink_channel *channel = to_glink_channel(ept);
1308
1309         return __qcom_glink_send(channel, data, len, false);
1310 }
1311
1312 /*
1313  * Finds the device_node for the glink child interested in this channel.
1314  */
1315 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1316                                                     const char *channel)
1317 {
1318         struct device_node *child;
1319         const char *name;
1320         const char *key;
1321         int ret;
1322
1323         for_each_available_child_of_node(node, child) {
1324                 key = "qcom,glink-channels";
1325                 ret = of_property_read_string(child, key, &name);
1326                 if (ret)
1327                         continue;
1328
1329                 if (strcmp(name, channel) == 0)
1330                         return child;
1331         }
1332
1333         return NULL;
1334 }
1335
1336 static const struct rpmsg_device_ops glink_device_ops = {
1337         .create_ept = qcom_glink_create_ept,
1338         .announce_create = qcom_glink_announce_create,
1339 };
1340
1341 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1342         .destroy_ept = qcom_glink_destroy_ept,
1343         .send = qcom_glink_send,
1344         .trysend = qcom_glink_trysend,
1345 };
1346
1347 static void qcom_glink_rpdev_release(struct device *dev)
1348 {
1349         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1350         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1351
1352         channel->rpdev = NULL;
1353         kfree(rpdev);
1354 }
1355
1356 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1357                               char *name)
1358 {
1359         struct glink_channel *channel;
1360         struct rpmsg_device *rpdev;
1361         bool create_device = false;
1362         struct device_node *node;
1363         int lcid;
1364         int ret;
1365         unsigned long flags;
1366
1367         spin_lock_irqsave(&glink->idr_lock, flags);
1368         idr_for_each_entry(&glink->lcids, channel, lcid) {
1369                 if (!strcmp(channel->name, name))
1370                         break;
1371         }
1372         spin_unlock_irqrestore(&glink->idr_lock, flags);
1373
1374         if (!channel) {
1375                 channel = qcom_glink_alloc_channel(glink, name);
1376                 if (IS_ERR(channel))
1377                         return PTR_ERR(channel);
1378
1379                 /* The opening dance was initiated by the remote */
1380                 create_device = true;
1381         }
1382
1383         spin_lock_irqsave(&glink->idr_lock, flags);
1384         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1385         if (ret < 0) {
1386                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1387                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1388                 goto free_channel;
1389         }
1390         channel->rcid = ret;
1391         spin_unlock_irqrestore(&glink->idr_lock, flags);
1392
1393         complete(&channel->open_req);
1394
1395         if (create_device) {
1396                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1397                 if (!rpdev) {
1398                         ret = -ENOMEM;
1399                         goto rcid_remove;
1400                 }
1401
1402                 rpdev->ept = &channel->ept;
1403                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1404                 rpdev->src = RPMSG_ADDR_ANY;
1405                 rpdev->dst = RPMSG_ADDR_ANY;
1406                 rpdev->ops = &glink_device_ops;
1407
1408                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1409                 rpdev->dev.of_node = node;
1410                 rpdev->dev.parent = glink->dev;
1411                 rpdev->dev.release = qcom_glink_rpdev_release;
1412
1413                 ret = rpmsg_register_device(rpdev);
1414                 if (ret)
1415                         goto rcid_remove;
1416
1417                 channel->rpdev = rpdev;
1418         }
1419
1420         return 0;
1421
1422 rcid_remove:
1423         spin_lock_irqsave(&glink->idr_lock, flags);
1424         idr_remove(&glink->rcids, channel->rcid);
1425         channel->rcid = 0;
1426         spin_unlock_irqrestore(&glink->idr_lock, flags);
1427 free_channel:
1428         /* Release the reference, iff we took it */
1429         if (create_device)
1430                 kref_put(&channel->refcount, qcom_glink_channel_release);
1431
1432         return ret;
1433 }
1434
1435 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1436 {
1437         struct rpmsg_channel_info chinfo;
1438         struct glink_channel *channel;
1439         unsigned long flags;
1440
1441         spin_lock_irqsave(&glink->idr_lock, flags);
1442         channel = idr_find(&glink->rcids, rcid);
1443         spin_unlock_irqrestore(&glink->idr_lock, flags);
1444         if (WARN(!channel, "close request on unknown channel\n"))
1445                 return;
1446
1447         /* cancel pending rx_done work */
1448         cancel_work_sync(&channel->intent_work);
1449
1450         if (channel->rpdev) {
1451                 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1452                 chinfo.src = RPMSG_ADDR_ANY;
1453                 chinfo.dst = RPMSG_ADDR_ANY;
1454
1455                 rpmsg_unregister_device(glink->dev, &chinfo);
1456         }
1457
1458         qcom_glink_send_close_ack(glink, channel->rcid);
1459
1460         spin_lock_irqsave(&glink->idr_lock, flags);
1461         idr_remove(&glink->rcids, channel->rcid);
1462         channel->rcid = 0;
1463         spin_unlock_irqrestore(&glink->idr_lock, flags);
1464
1465         kref_put(&channel->refcount, qcom_glink_channel_release);
1466 }
1467
1468 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1469 {
1470         struct glink_channel *channel;
1471         unsigned long flags;
1472
1473         spin_lock_irqsave(&glink->idr_lock, flags);
1474         channel = idr_find(&glink->lcids, lcid);
1475         if (WARN(!channel, "close ack on unknown channel\n")) {
1476                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1477                 return;
1478         }
1479
1480         idr_remove(&glink->lcids, channel->lcid);
1481         channel->lcid = 0;
1482         spin_unlock_irqrestore(&glink->idr_lock, flags);
1483
1484         kref_put(&channel->refcount, qcom_glink_channel_release);
1485 }
1486
1487 static void qcom_glink_work(struct work_struct *work)
1488 {
1489         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1490                                                 rx_work);
1491         struct glink_defer_cmd *dcmd;
1492         struct glink_msg *msg;
1493         unsigned long flags;
1494         unsigned int param1;
1495         unsigned int param2;
1496         unsigned int cmd;
1497
1498         for (;;) {
1499                 spin_lock_irqsave(&glink->rx_lock, flags);
1500                 if (list_empty(&glink->rx_queue)) {
1501                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1502                         break;
1503                 }
1504                 dcmd = list_first_entry(&glink->rx_queue,
1505                                         struct glink_defer_cmd, node);
1506                 list_del(&dcmd->node);
1507                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1508
1509                 msg = &dcmd->msg;
1510                 cmd = le16_to_cpu(msg->cmd);
1511                 param1 = le16_to_cpu(msg->param1);
1512                 param2 = le32_to_cpu(msg->param2);
1513
1514                 switch (cmd) {
1515                 case RPM_CMD_VERSION:
1516                         qcom_glink_receive_version(glink, param1, param2);
1517                         break;
1518                 case RPM_CMD_VERSION_ACK:
1519                         qcom_glink_receive_version_ack(glink, param1, param2);
1520                         break;
1521                 case RPM_CMD_OPEN:
1522                         qcom_glink_rx_open(glink, param1, msg->data);
1523                         break;
1524                 case RPM_CMD_CLOSE:
1525                         qcom_glink_rx_close(glink, param1);
1526                         break;
1527                 case RPM_CMD_CLOSE_ACK:
1528                         qcom_glink_rx_close_ack(glink, param1);
1529                         break;
1530                 case RPM_CMD_RX_INTENT_REQ:
1531                         qcom_glink_handle_intent_req(glink, param1, param2);
1532                         break;
1533                 default:
1534                         WARN(1, "Unknown defer object %d\n", cmd);
1535                         break;
1536                 }
1537
1538                 kfree(dcmd);
1539         }
1540 }
1541
1542 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1543 {
1544         struct glink_defer_cmd *dcmd;
1545         struct glink_defer_cmd *tmp;
1546
1547         /* cancel any pending deferred rx_work */
1548         cancel_work_sync(&glink->rx_work);
1549
1550         list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1551                 kfree(dcmd);
1552 }
1553
1554 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1555                                            unsigned long features,
1556                                            struct qcom_glink_pipe *rx,
1557                                            struct qcom_glink_pipe *tx,
1558                                            bool intentless)
1559 {
1560         int irq;
1561         int ret;
1562         struct qcom_glink *glink;
1563
1564         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1565         if (!glink)
1566                 return ERR_PTR(-ENOMEM);
1567
1568         glink->dev = dev;
1569         glink->tx_pipe = tx;
1570         glink->rx_pipe = rx;
1571
1572         glink->features = features;
1573         glink->intentless = intentless;
1574
1575         mutex_init(&glink->tx_lock);
1576         spin_lock_init(&glink->rx_lock);
1577         INIT_LIST_HEAD(&glink->rx_queue);
1578         INIT_WORK(&glink->rx_work, qcom_glink_work);
1579
1580         spin_lock_init(&glink->idr_lock);
1581         idr_init(&glink->lcids);
1582         idr_init(&glink->rcids);
1583
1584         glink->mbox_client.dev = dev;
1585         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1586         if (IS_ERR(glink->mbox_chan)) {
1587                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1588                         dev_err(dev, "failed to acquire IPC channel\n");
1589                 return ERR_CAST(glink->mbox_chan);
1590         }
1591
1592         irq = of_irq_get(dev->of_node, 0);
1593         ret = devm_request_irq(dev, irq,
1594                                qcom_glink_native_intr,
1595                                IRQF_NO_SUSPEND | IRQF_SHARED,
1596                                "glink-native", glink);
1597         if (ret) {
1598                 dev_err(dev, "failed to request IRQ\n");
1599                 return ERR_PTR(ret);
1600         }
1601
1602         glink->irq = irq;
1603
1604         ret = qcom_glink_send_version(glink);
1605         if (ret)
1606                 return ERR_PTR(ret);
1607
1608         return glink;
1609 }
1610 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1611
1612 static int qcom_glink_remove_device(struct device *dev, void *data)
1613 {
1614         device_unregister(dev);
1615
1616         return 0;
1617 }
1618
1619 void qcom_glink_native_remove(struct qcom_glink *glink)
1620 {
1621         struct glink_channel *channel;
1622         int cid;
1623         int ret;
1624
1625         disable_irq(glink->irq);
1626         qcom_glink_cancel_rx_work(glink);
1627
1628         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1629         if (ret)
1630                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1631
1632         /* Release any defunct local channels, waiting for close-ack */
1633         idr_for_each_entry(&glink->lcids, channel, cid)
1634                 kref_put(&channel->refcount, qcom_glink_channel_release);
1635
1636         /* Release any defunct local channels, waiting for close-req */
1637         idr_for_each_entry(&glink->rcids, channel, cid)
1638                 kref_put(&channel->refcount, qcom_glink_channel_release);
1639
1640         idr_destroy(&glink->lcids);
1641         idr_destroy(&glink->rcids);
1642         mbox_free_channel(glink->mbox_chan);
1643 }
1644 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1645
1646 void qcom_glink_native_unregister(struct qcom_glink *glink)
1647 {
1648         device_unregister(glink->dev);
1649 }
1650 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1651
1652 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1653 MODULE_LICENSE("GPL v2");