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         spinlock_t 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         unsigned long flags;
 248
 249         spin_lock_irqsave(&channel->intent_lock, flags);
 250         idr_destroy(&channel->liids);
 251         idr_destroy(&channel->riids);
 252         spin_unlock_irqrestore(&channel->intent_lock, flags);
 253
 254         kfree(channel->name);
 255         kfree(channel);
 256 }
 257
 258 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 259 {
 260         return glink->rx_pipe->avail(glink->rx_pipe);
 261 }
 262
 263 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 264                                void *data, unsigned int offset, size_t count)
 265 {
 266         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 267 }
 268
 269 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 270 {
 271         glink->rx_pipe->advance(glink->rx_pipe, count);
 272 }
 273
 274 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 275 {
 276         return glink->tx_pipe->avail(glink->tx_pipe);
 277 }
 278
 279 static void qcom_glink_tx_write(struct qcom_glink *glink,
 280                                 const void *hdr, size_t hlen,
 281                                 const void *data, size_t dlen)
 282 {
 283         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 284 }
 285
 286 static int qcom_glink_tx(struct qcom_glink *glink,
 287                          const void *hdr, size_t hlen,
 288                          const void *data, size_t dlen, bool wait)
 289 {
 290         unsigned int tlen = hlen + dlen;
 291         unsigned long flags;
 292         int ret = 0;
 293
 294         /* Reject packets that are too big */
 295         if (tlen >= glink->tx_pipe->length)
 296                 return -EINVAL;
 297
 298         spin_lock_irqsave(&glink->tx_lock, flags);
 299
 300         while (qcom_glink_tx_avail(glink) < tlen) {
 301                 if (!wait) {
 302                         ret = -EAGAIN;
 303                         goto out;
 304                 }
 305
 306                 /* Wait without holding the tx_lock */
 307                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 308
 309                 usleep_range(10000, 15000);
 310
 311                 spin_lock_irqsave(&glink->tx_lock, flags);
 312         }
 313
 314         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 315
 316         mbox_send_message(glink->mbox_chan, NULL);
 317         mbox_client_txdone(glink->mbox_chan, 0);
 318
 319 out:
 320         spin_unlock_irqrestore(&glink->tx_lock, flags);
 321
 322         return ret;
 323 }
 324
 325 static int qcom_glink_send_version(struct qcom_glink *glink)
 326 {
 327         struct glink_msg msg;
 328
 329         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 330         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 331         msg.param2 = cpu_to_le32(glink->features);
 332
 333         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 334 }
 335
 336 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 337 {
 338         struct glink_msg msg;
 339
 340         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 341         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 342         msg.param2 = cpu_to_le32(glink->features);
 343
 344         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 345 }
 346
 347 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 348                                      struct glink_channel *channel)
 349 {
 350         struct glink_msg msg;
 351
 352         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 353         msg.param1 = cpu_to_le16(channel->rcid);
 354         msg.param2 = cpu_to_le32(0);
 355
 356         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 357 }
 358
 359 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 360                                              unsigned int cid, bool granted)
 361 {
 362         struct glink_channel *channel;
 363         unsigned long flags;
 364
 365         spin_lock_irqsave(&glink->idr_lock, flags);
 366         channel = idr_find(&glink->rcids, cid);
 367         spin_unlock_irqrestore(&glink->idr_lock, flags);
 368         if (!channel) {
 369                 dev_err(glink->dev, "unable to find channel\n");
 370                 return;
 371         }
 372
 373         channel->intent_req_result = granted;
 374         complete(&channel->intent_req_comp);
 375 }
 376
 377 /**
 378  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 379  * @glink: Ptr to the glink edge
 380  * @channel: Ptr to the channel that the open req is sent
 381  *
 382  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 383  * Will return with refcount held, regardless of outcome.
 384  *
 385  * Returns 0 on success, negative errno otherwise.
 386  */
 387 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 388                                     struct glink_channel *channel)
 389 {
 390         struct {
 391                 struct glink_msg msg;
 392                 u8 name[GLINK_NAME_SIZE];
 393         } __packed req;
 394         int name_len = strlen(channel->name) + 1;
 395         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 396         int ret;
 397         unsigned long flags;
 398
 399         kref_get(&channel->refcount);
 400
 401         spin_lock_irqsave(&glink->idr_lock, flags);
 402         ret = idr_alloc_cyclic(&glink->lcids, channel,
 403                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 404                                GFP_ATOMIC);
 405         spin_unlock_irqrestore(&glink->idr_lock, flags);
 406         if (ret < 0)
 407                 return ret;
 408
 409         channel->lcid = ret;
 410
 411         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 412         req.msg.param1 = cpu_to_le16(channel->lcid);
 413         req.msg.param2 = cpu_to_le32(name_len);
 414         strcpy(req.name, channel->name);
 415
 416         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 417         if (ret)
 418                 goto remove_idr;
 419
 420         return 0;
 421
 422 remove_idr:
 423         spin_lock_irqsave(&glink->idr_lock, flags);
 424         idr_remove(&glink->lcids, channel->lcid);
 425         channel->lcid = 0;
 426         spin_unlock_irqrestore(&glink->idr_lock, flags);
 427
 428         return ret;
 429 }
 430
 431 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 432                                       struct glink_channel *channel)
 433 {
 434         struct glink_msg req;
 435
 436         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 437         req.param1 = cpu_to_le16(channel->lcid);
 438         req.param2 = 0;
 439
 440         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 441 }
 442
 443 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 444                                       unsigned int rcid)
 445 {
 446         struct glink_msg req;
 447
 448         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 449         req.param1 = cpu_to_le16(rcid);
 450         req.param2 = 0;
 451
 452         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 453 }
 454
 455 static void qcom_glink_rx_done_work(struct work_struct *work)
 456 {
 457         struct glink_channel *channel = container_of(work, struct glink_channel,
 458                                                      intent_work);
 459         struct qcom_glink *glink = channel->glink;
 460         struct glink_core_rx_intent *intent, *tmp;
 461         struct {
 462                 u16 id;
 463                 u16 lcid;
 464                 u32 liid;
 465         } __packed cmd;
 466
 467         unsigned int cid = channel->lcid;
 468         unsigned int iid;
 469         bool reuse;
 470         unsigned long flags;
 471
 472         spin_lock_irqsave(&channel->intent_lock, flags);
 473         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 474                 list_del(&intent->node);
 475                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 476                 iid = intent->id;
 477                 reuse = intent->reuse;
 478
 479                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 480                 cmd.lcid = cid;
 481                 cmd.liid = iid;
 482
 483                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 484                 if (!reuse) {
 485                         kfree(intent->data);
 486                         kfree(intent);
 487                 }
 488                 spin_lock_irqsave(&channel->intent_lock, flags);
 489         }
 490         spin_unlock_irqrestore(&channel->intent_lock, flags);
 491 }
 492
 493 static void qcom_glink_rx_done(struct qcom_glink *glink,
 494                                struct glink_channel *channel,
 495                                struct glink_core_rx_intent *intent)
 496 {
 497         /* We don't send RX_DONE to intentless systems */
 498         if (glink->intentless) {
 499                 kfree(intent->data);
 500                 kfree(intent);
 501                 return;
 502         }
 503
 504         /* Take it off the tree of receive intents */
 505         if (!intent->reuse) {
 506                 spin_lock(&channel->intent_lock);
 507                 idr_remove(&channel->liids, intent->id);
 508                 spin_unlock(&channel->intent_lock);
 509         }
 510
 511         /* Schedule the sending of a rx_done indication */
 512         spin_lock(&channel->intent_lock);
 513         list_add_tail(&intent->node, &channel->done_intents);
 514         spin_unlock(&channel->intent_lock);
 515
 516         schedule_work(&channel->intent_work);
 517 }
 518
 519 /**
 520  * qcom_glink_receive_version() - receive version/features from remote system
 521  *
 522  * @glink:      pointer to transport interface
 523  * @r_version:  remote version
 524  * @r_features: remote features
 525  *
 526  * This function is called in response to a remote-initiated version/feature
 527  * negotiation sequence.
 528  */
 529 static void qcom_glink_receive_version(struct qcom_glink *glink,
 530                                        u32 version,
 531                                        u32 features)
 532 {
 533         switch (version) {
 534         case 0:
 535                 break;
 536         case GLINK_VERSION_1:
 537                 glink->features &= features;
 538                 /* FALLTHROUGH */
 539         default:
 540                 qcom_glink_send_version_ack(glink);
 541                 break;
 542         }
 543 }
 544
 545 /**
 546  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 547  *
 548  * @glink:      pointer to transport interface
 549  * @r_version:  remote version response
 550  * @r_features: remote features response
 551  *
 552  * This function is called in response to a local-initiated version/feature
 553  * negotiation sequence and is the counter-offer from the remote side based
 554  * upon the initial version and feature set requested.
 555  */
 556 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 557                                            u32 version,
 558                                            u32 features)
 559 {
 560         switch (version) {
 561         case 0:
 562                 /* Version negotiation failed */
 563                 break;
 564         case GLINK_VERSION_1:
 565                 if (features == glink->features)
 566                         break;
 567
 568                 glink->features &= features;
 569                 /* FALLTHROUGH */
 570         default:
 571                 qcom_glink_send_version(glink);
 572                 break;
 573         }
 574 }
 575
 576 /**
 577  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 578                                       wire format and transmit
 579  * @glink:      The transport to transmit on.
 580  * @channel:    The glink channel
 581  * @granted:    The request response to encode.
 582  *
 583  * Return: 0 on success or standard Linux error code.
 584  */
 585 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 586                                           struct glink_channel *channel,
 587                                           bool granted)
 588 {
 589         struct glink_msg msg;
 590
 591         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 592         msg.param1 = cpu_to_le16(channel->lcid);
 593         msg.param2 = cpu_to_le32(granted);
 594
 595         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 596
 597         return 0;
 598 }
 599
 600 /**
 601  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 602  *                         transmit
 603  * @glink:      The transport to transmit on.
 604  * @channel:    The local channel
 605  * @size:       The intent to pass on to remote.
 606  *
 607  * Return: 0 on success or standard Linux error code.
 608  */
 609 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 610                                        struct glink_channel *channel,
 611                                        struct glink_core_rx_intent *intent)
 612 {
 613         struct command {
 614                 u16 id;
 615                 u16 lcid;
 616                 u32 count;
 617                 u32 size;
 618                 u32 liid;
 619         } __packed;
 620         struct command cmd;
 621
 622         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 623         cmd.lcid = cpu_to_le16(channel->lcid);
 624         cmd.count = cpu_to_le32(1);
 625         cmd.size = cpu_to_le32(intent->size);
 626         cmd.liid = cpu_to_le32(intent->id);
 627
 628         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 629
 630         return 0;
 631 }
 632
 633 static struct glink_core_rx_intent *
 634 qcom_glink_alloc_intent(struct qcom_glink *glink,
 635                         struct glink_channel *channel,
 636                         size_t size,
 637                         bool reuseable)
 638 {
 639         struct glink_core_rx_intent *intent;
 640         int ret;
 641         unsigned long flags;
 642
 643         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 644         if (!intent)
 645                 return NULL;
 646
 647         intent->data = kzalloc(size, GFP_KERNEL);
 648         if (!intent->data)
 649                 goto free_intent;
 650
 651         spin_lock_irqsave(&channel->intent_lock, flags);
 652         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 653         if (ret < 0) {
 654                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 655                 goto free_data;
 656         }
 657         spin_unlock_irqrestore(&channel->intent_lock, flags);
 658
 659         intent->id = ret;
 660         intent->size = size;
 661         intent->reuse = reuseable;
 662
 663         return intent;
 664
 665 free_data:
 666         kfree(intent->data);
 667 free_intent:
 668         kfree(intent);
 669         return NULL;
 670 }
 671
 672 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 673                                       u32 cid, uint32_t iid,
 674                                       bool reuse)
 675 {
 676         struct glink_core_rx_intent *intent;
 677         struct glink_channel *channel;
 678         unsigned long flags;
 679
 680         spin_lock_irqsave(&glink->idr_lock, flags);
 681         channel = idr_find(&glink->rcids, cid);
 682         spin_unlock_irqrestore(&glink->idr_lock, flags);
 683         if (!channel) {
 684                 dev_err(glink->dev, "invalid channel id received\n");
 685                 return;
 686         }
 687
 688         spin_lock_irqsave(&channel->intent_lock, flags);
 689         intent = idr_find(&channel->riids, iid);
 690
 691         if (!intent) {
 692                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 693                 dev_err(glink->dev, "invalid intent id received\n");
 694                 return;
 695         }
 696
 697         intent->in_use = false;
 698
 699         if (!reuse) {
 700                 idr_remove(&channel->riids, intent->id);
 701                 kfree(intent);
 702         }
 703         spin_unlock_irqrestore(&channel->intent_lock, flags);
 704 }
 705
 706 /**
 707  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 708  *                                          from remote side
 709  * if_ptr:      Pointer to the transport interface
 710  * rcid:        Remote channel ID
 711  * size:        size of the intent
 712  *
 713  * The function searches for the local channel to which the request for
 714  * rx_intent has arrived and allocates and notifies the remote back
 715  */
 716 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 717                                          u32 cid, size_t size)
 718 {
 719         struct glink_core_rx_intent *intent;
 720         struct glink_channel *channel;
 721         unsigned long flags;
 722
 723         spin_lock_irqsave(&glink->idr_lock, flags);
 724         channel = idr_find(&glink->rcids, cid);
 725         spin_unlock_irqrestore(&glink->idr_lock, flags);
 726
 727         if (!channel) {
 728                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 729                 return;
 730         }
 731
 732         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 733         if (intent)
 734                 qcom_glink_advertise_intent(glink, channel, intent);
 735
 736         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 737 }
 738
 739 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 740 {
 741         struct glink_defer_cmd *dcmd;
 742
 743         extra = ALIGN(extra, 8);
 744
 745         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 746                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 747                 return -ENXIO;
 748         }
 749
 750         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 751         if (!dcmd)
 752                 return -ENOMEM;
 753
 754         INIT_LIST_HEAD(&dcmd->node);
 755
 756         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 757
 758         spin_lock(&glink->rx_lock);
 759         list_add_tail(&dcmd->node, &glink->rx_queue);
 760         spin_unlock(&glink->rx_lock);
 761
 762         schedule_work(&glink->rx_work);
 763         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 764
 765         return 0;
 766 }
 767
 768 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 769 {
 770         struct glink_core_rx_intent *intent;
 771         struct glink_channel *channel;
 772         struct {
 773                 struct glink_msg msg;
 774                 __le32 chunk_size;
 775                 __le32 left_size;
 776         } __packed hdr;
 777         unsigned int chunk_size;
 778         unsigned int left_size;
 779         unsigned int rcid;
 780         unsigned int liid;
 781         int ret = 0;
 782         unsigned long flags;
 783
 784         if (avail < sizeof(hdr)) {
 785                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 786                 return -EAGAIN;
 787         }
 788
 789         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 790         chunk_size = le32_to_cpu(hdr.chunk_size);
 791         left_size = le32_to_cpu(hdr.left_size);
 792
 793         if (avail < sizeof(hdr) + chunk_size) {
 794                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 795                 return -EAGAIN;
 796         }
 797
 798         if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
 799                 return -EINVAL;
 800
 801         rcid = le16_to_cpu(hdr.msg.param1);
 802         spin_lock_irqsave(&glink->idr_lock, flags);
 803         channel = idr_find(&glink->rcids, rcid);
 804         spin_unlock_irqrestore(&glink->idr_lock, flags);
 805         if (!channel) {
 806                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 807
 808                 /* Drop the message */
 809                 goto advance_rx;
 810         }
 811
 812         if (glink->intentless) {
 813                 /* Might have an ongoing, fragmented, message to append */
 814                 if (!channel->buf) {
 815                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 816                         if (!intent)
 817                                 return -ENOMEM;
 818
 819                         intent->data = kmalloc(chunk_size + left_size,
 820                                                GFP_ATOMIC);
 821                         if (!intent->data) {
 822                                 kfree(intent);
 823                                 return -ENOMEM;
 824                         }
 825
 826                         intent->id = 0xbabababa;
 827                         intent->size = chunk_size + left_size;
 828                         intent->offset = 0;
 829
 830                         channel->buf = intent;
 831                 } else {
 832                         intent = channel->buf;
 833                 }
 834         } else {
 835                 liid = le32_to_cpu(hdr.msg.param2);
 836
 837                 spin_lock_irqsave(&channel->intent_lock, flags);
 838                 intent = idr_find(&channel->liids, liid);
 839                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 840
 841                 if (!intent) {
 842                         dev_err(glink->dev,
 843                                 "no intent found for channel %s intent %d",
 844                                 channel->name, liid);
 845                         goto advance_rx;
 846                 }
 847         }
 848
 849         if (intent->size - intent->offset < chunk_size) {
 850                 dev_err(glink->dev, "Insufficient space in intent\n");
 851
 852                 /* The packet header lied, drop payload */
 853                 goto advance_rx;
 854         }
 855
 856         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 857                            sizeof(hdr), chunk_size);
 858         intent->offset += chunk_size;
 859
 860         /* Handle message when no fragments remain to be received */
 861         if (!left_size) {
 862                 spin_lock(&channel->recv_lock);
 863                 if (channel->ept.cb) {
 864                         channel->ept.cb(channel->ept.rpdev,
 865                                         intent->data,
 866                                         intent->offset,
 867                                         channel->ept.priv,
 868                                         RPMSG_ADDR_ANY);
 869                 }
 870                 spin_unlock(&channel->recv_lock);
 871
 872                 intent->offset = 0;
 873                 channel->buf = NULL;
 874
 875                 qcom_glink_rx_done(glink, channel, intent);
 876         }
 877
 878 advance_rx:
 879         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 880
 881         return ret;
 882 }
 883
 884 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 885                                      unsigned int cid,
 886                                      unsigned int count,
 887                                      size_t avail)
 888 {
 889         struct glink_core_rx_intent *intent;
 890         struct glink_channel *channel;
 891         struct intent_pair {
 892                 __le32 size;
 893                 __le32 iid;
 894         };
 895
 896         struct {
 897                 struct glink_msg msg;
 898                 struct intent_pair intents[];
 899         } __packed * msg;
 900
 901         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
 902         int ret;
 903         int i;
 904         unsigned long flags;
 905
 906         if (avail < msglen) {
 907                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 908                 return;
 909         }
 910
 911         spin_lock_irqsave(&glink->idr_lock, flags);
 912         channel = idr_find(&glink->rcids, cid);
 913         spin_unlock_irqrestore(&glink->idr_lock, flags);
 914         if (!channel) {
 915                 dev_err(glink->dev, "intents for non-existing channel\n");
 916                 return;
 917         }
 918
 919         msg = kmalloc(msglen, GFP_ATOMIC);
 920         if (!msg)
 921                 return;
 922
 923         qcom_glink_rx_peak(glink, msg, 0, msglen);
 924
 925         for (i = 0; i < count; ++i) {
 926                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 927                 if (!intent)
 928                         break;
 929
 930                 intent->id = le32_to_cpu(msg->intents[i].iid);
 931                 intent->size = le32_to_cpu(msg->intents[i].size);
 932
 933                 spin_lock_irqsave(&channel->intent_lock, flags);
 934                 ret = idr_alloc(&channel->riids, intent,
 935                                 intent->id, intent->id + 1, GFP_ATOMIC);
 936                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 937
 938                 if (ret < 0)
 939                         dev_err(glink->dev, "failed to store remote intent\n");
 940         }
 941
 942         kfree(msg);
 943         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 944 }
 945
 946 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 947 {
 948         struct glink_channel *channel;
 949
 950         spin_lock(&glink->idr_lock);
 951         channel = idr_find(&glink->lcids, lcid);
 952         spin_unlock(&glink->idr_lock);
 953         if (!channel) {
 954                 dev_err(glink->dev, "Invalid open ack packet\n");
 955                 return -EINVAL;
 956         }
 957
 958         complete(&channel->open_ack);
 959
 960         return 0;
 961 }
 962
 963 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 964 {
 965         struct qcom_glink *glink = data;
 966         struct glink_msg msg;
 967         unsigned int param1;
 968         unsigned int param2;
 969         unsigned int avail;
 970         unsigned int cmd;
 971         int ret = 0;
 972
 973         for (;;) {
 974                 avail = qcom_glink_rx_avail(glink);
 975                 if (avail < sizeof(msg))
 976                         break;
 977
 978                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 979
 980                 cmd = le16_to_cpu(msg.cmd);
 981                 param1 = le16_to_cpu(msg.param1);
 982                 param2 = le32_to_cpu(msg.param2);
 983
 984                 switch (cmd) {
 985                 case RPM_CMD_VERSION:
 986                 case RPM_CMD_VERSION_ACK:
 987                 case RPM_CMD_CLOSE:
 988                 case RPM_CMD_CLOSE_ACK:
 989                 case RPM_CMD_RX_INTENT_REQ:
 990                         ret = qcom_glink_rx_defer(glink, 0);
 991                         break;
 992                 case RPM_CMD_OPEN_ACK:
 993                         ret = qcom_glink_rx_open_ack(glink, param1);
 994                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 995                         break;
 996                 case RPM_CMD_OPEN:
 997                         ret = qcom_glink_rx_defer(glink, param2);
 998                         break;
 999                 case RPM_CMD_TX_DATA:
1000                 case RPM_CMD_TX_DATA_CONT:
1001                         ret = qcom_glink_rx_data(glink, avail);
1002                         break;
1003                 case RPM_CMD_READ_NOTIF:
1004                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1005
1006                         mbox_send_message(glink->mbox_chan, NULL);
1007                         mbox_client_txdone(glink->mbox_chan, 0);
1008                         break;
1009                 case RPM_CMD_INTENT:
1010                         qcom_glink_handle_intent(glink, param1, param2, avail);
1011                         break;
1012                 case RPM_CMD_RX_DONE:
1013                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1014                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1015                         break;
1016                 case RPM_CMD_RX_DONE_W_REUSE:
1017                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1018                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1019                         break;
1020                 case RPM_CMD_RX_INTENT_REQ_ACK:
1021                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1022                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1023                         break;
1024                 default:
1025                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1026                         ret = -EINVAL;
1027                         break;
1028                 }
1029
1030                 if (ret)
1031                         break;
1032         }
1033
1034         return IRQ_HANDLED;
1035 }
1036
1037 /* Locally initiated rpmsg_create_ept */
1038 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1039                                                      const char *name)
1040 {
1041         struct glink_channel *channel;
1042         int ret;
1043         unsigned long flags;
1044
1045         channel = qcom_glink_alloc_channel(glink, name);
1046         if (IS_ERR(channel))
1047                 return ERR_CAST(channel);
1048
1049         ret = qcom_glink_send_open_req(glink, channel);
1050         if (ret)
1051                 goto release_channel;
1052
1053         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1054         if (!ret)
1055                 goto err_timeout;
1056
1057         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1058         if (!ret)
1059                 goto err_timeout;
1060
1061         qcom_glink_send_open_ack(glink, channel);
1062
1063         return channel;
1064
1065 err_timeout:
1066         /* qcom_glink_send_open_req() did register the channel in lcids*/
1067         spin_lock_irqsave(&glink->idr_lock, flags);
1068         idr_remove(&glink->lcids, channel->lcid);
1069         spin_unlock_irqrestore(&glink->idr_lock, flags);
1070
1071 release_channel:
1072         /* Release qcom_glink_send_open_req() reference */
1073         kref_put(&channel->refcount, qcom_glink_channel_release);
1074         /* Release qcom_glink_alloc_channel() reference */
1075         kref_put(&channel->refcount, qcom_glink_channel_release);
1076
1077         return ERR_PTR(-ETIMEDOUT);
1078 }
1079
1080 /* Remote initiated rpmsg_create_ept */
1081 static int qcom_glink_create_remote(struct qcom_glink *glink,
1082                                     struct glink_channel *channel)
1083 {
1084         int ret;
1085
1086         qcom_glink_send_open_ack(glink, channel);
1087
1088         ret = qcom_glink_send_open_req(glink, channel);
1089         if (ret)
1090                 goto close_link;
1091
1092         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1093         if (!ret) {
1094                 ret = -ETIMEDOUT;
1095                 goto close_link;
1096         }
1097
1098         return 0;
1099
1100 close_link:
1101         /*
1102          * Send a close request to "undo" our open-ack. The close-ack will
1103          * release the last reference.
1104          */
1105         qcom_glink_send_close_req(glink, channel);
1106
1107         /* Release qcom_glink_send_open_req() reference */
1108         kref_put(&channel->refcount, qcom_glink_channel_release);
1109
1110         return ret;
1111 }
1112
1113 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1114                                                     rpmsg_rx_cb_t cb,
1115                                                     void *priv,
1116                                                     struct rpmsg_channel_info
1117                                                                         chinfo)
1118 {
1119         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1120         struct glink_channel *channel;
1121         struct qcom_glink *glink = parent->glink;
1122         struct rpmsg_endpoint *ept;
1123         const char *name = chinfo.name;
1124         int cid;
1125         int ret;
1126         unsigned long flags;
1127
1128         spin_lock_irqsave(&glink->idr_lock, flags);
1129         idr_for_each_entry(&glink->rcids, channel, cid) {
1130                 if (!strcmp(channel->name, name))
1131                         break;
1132         }
1133         spin_unlock_irqrestore(&glink->idr_lock, flags);
1134
1135         if (!channel) {
1136                 channel = qcom_glink_create_local(glink, name);
1137                 if (IS_ERR(channel))
1138                         return NULL;
1139         } else {
1140                 ret = qcom_glink_create_remote(glink, channel);
1141                 if (ret)
1142                         return NULL;
1143         }
1144
1145         ept = &channel->ept;
1146         ept->rpdev = rpdev;
1147         ept->cb = cb;
1148         ept->priv = priv;
1149         ept->ops = &glink_endpoint_ops;
1150
1151         return ept;
1152 }
1153
1154 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1155 {
1156         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1157         struct device_node *np = rpdev->dev.of_node;
1158         struct qcom_glink *glink = channel->glink;
1159         struct glink_core_rx_intent *intent;
1160         const struct property *prop = NULL;
1161         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1162         int num_intents;
1163         int num_groups = 1;
1164         __be32 *val = defaults;
1165         int size;
1166
1167         if (glink->intentless)
1168                 return 0;
1169
1170         prop = of_find_property(np, "qcom,intents", NULL);
1171         if (prop) {
1172                 val = prop->value;
1173                 num_groups = prop->length / sizeof(u32) / 2;
1174         }
1175
1176         /* Channel is now open, advertise base set of intents */
1177         while (num_groups--) {
1178                 size = be32_to_cpup(val++);
1179                 num_intents = be32_to_cpup(val++);
1180                 while (num_intents--) {
1181                         intent = qcom_glink_alloc_intent(glink, channel, size,
1182                                                          true);
1183                         if (!intent)
1184                                 break;
1185
1186                         qcom_glink_advertise_intent(glink, channel, intent);
1187                 }
1188         }
1189         return 0;
1190 }
1191
1192 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1193 {
1194         struct glink_channel *channel = to_glink_channel(ept);
1195         struct qcom_glink *glink = channel->glink;
1196         unsigned long flags;
1197
1198         spin_lock_irqsave(&channel->recv_lock, flags);
1199         channel->ept.cb = NULL;
1200         spin_unlock_irqrestore(&channel->recv_lock, flags);
1201
1202         /* Decouple the potential rpdev from the channel */
1203         channel->rpdev = NULL;
1204
1205         qcom_glink_send_close_req(glink, channel);
1206 }
1207
1208 static int qcom_glink_request_intent(struct qcom_glink *glink,
1209                                      struct glink_channel *channel,
1210                                      size_t size)
1211 {
1212         struct {
1213                 u16 id;
1214                 u16 cid;
1215                 u32 size;
1216         } __packed cmd;
1217
1218         int ret;
1219
1220         mutex_lock(&channel->intent_req_lock);
1221
1222         reinit_completion(&channel->intent_req_comp);
1223
1224         cmd.id = RPM_CMD_RX_INTENT_REQ;
1225         cmd.cid = channel->lcid;
1226         cmd.size = size;
1227
1228         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1229         if (ret)
1230                 goto unlock;
1231
1232         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1233         if (!ret) {
1234                 dev_err(glink->dev, "intent request timed out\n");
1235                 ret = -ETIMEDOUT;
1236         } else {
1237                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1238         }
1239
1240 unlock:
1241         mutex_unlock(&channel->intent_req_lock);
1242         return ret;
1243 }
1244
1245 static int __qcom_glink_send(struct glink_channel *channel,
1246                              void *data, int len, bool wait)
1247 {
1248         struct qcom_glink *glink = channel->glink;
1249         struct glink_core_rx_intent *intent = NULL;
1250         struct glink_core_rx_intent *tmp;
1251         int iid = 0;
1252         struct {
1253                 struct glink_msg msg;
1254                 __le32 chunk_size;
1255                 __le32 left_size;
1256         } __packed req;
1257         int ret;
1258         unsigned long flags;
1259
1260         if (!glink->intentless) {
1261                 while (!intent) {
1262                         spin_lock_irqsave(&channel->intent_lock, flags);
1263                         idr_for_each_entry(&channel->riids, tmp, iid) {
1264                                 if (tmp->size >= len && !tmp->in_use) {
1265                                         if (!intent)
1266                                                 intent = tmp;
1267                                         else if (intent->size > tmp->size)
1268                                                 intent = tmp;
1269                                         if (intent->size == len)
1270                                                 break;
1271                                 }
1272                         }
1273                         if (intent)
1274                                 intent->in_use = true;
1275                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1276
1277                         /* We found an available intent */
1278                         if (intent)
1279                                 break;
1280
1281                         if (!wait)
1282                                 return -EBUSY;
1283
1284                         ret = qcom_glink_request_intent(glink, channel, len);
1285                         if (ret < 0)
1286                                 return ret;
1287                 }
1288
1289                 iid = intent->id;
1290         }
1291
1292         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1293         req.msg.param1 = cpu_to_le16(channel->lcid);
1294         req.msg.param2 = cpu_to_le32(iid);
1295         req.chunk_size = cpu_to_le32(len);
1296         req.left_size = cpu_to_le32(0);
1297
1298         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1299
1300         /* Mark intent available if we failed */
1301         if (ret && intent)
1302                 intent->in_use = false;
1303
1304         return ret;
1305 }
1306
1307 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1308 {
1309         struct glink_channel *channel = to_glink_channel(ept);
1310
1311         return __qcom_glink_send(channel, data, len, true);
1312 }
1313
1314 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1315 {
1316         struct glink_channel *channel = to_glink_channel(ept);
1317
1318         return __qcom_glink_send(channel, data, len, false);
1319 }
1320
1321 /*
1322  * Finds the device_node for the glink child interested in this channel.
1323  */
1324 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1325                                                     const char *channel)
1326 {
1327         struct device_node *child;
1328         const char *name;
1329         const char *key;
1330         int ret;
1331
1332         for_each_available_child_of_node(node, child) {
1333                 key = "qcom,glink-channels";
1334                 ret = of_property_read_string(child, key, &name);
1335                 if (ret)
1336                         continue;
1337
1338                 if (strcmp(name, channel) == 0)
1339                         return child;
1340         }
1341
1342         return NULL;
1343 }
1344
1345 static const struct rpmsg_device_ops glink_device_ops = {
1346         .create_ept = qcom_glink_create_ept,
1347         .announce_create = qcom_glink_announce_create,
1348 };
1349
1350 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1351         .destroy_ept = qcom_glink_destroy_ept,
1352         .send = qcom_glink_send,
1353         .trysend = qcom_glink_trysend,
1354 };
1355
1356 static void qcom_glink_rpdev_release(struct device *dev)
1357 {
1358         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1359         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1360
1361         channel->rpdev = NULL;
1362         kfree(rpdev);
1363 }
1364
1365 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1366                               char *name)
1367 {
1368         struct glink_channel *channel;
1369         struct rpmsg_device *rpdev;
1370         bool create_device = false;
1371         struct device_node *node;
1372         int lcid;
1373         int ret;
1374         unsigned long flags;
1375
1376         spin_lock_irqsave(&glink->idr_lock, flags);
1377         idr_for_each_entry(&glink->lcids, channel, lcid) {
1378                 if (!strcmp(channel->name, name))
1379                         break;
1380         }
1381         spin_unlock_irqrestore(&glink->idr_lock, flags);
1382
1383         if (!channel) {
1384                 channel = qcom_glink_alloc_channel(glink, name);
1385                 if (IS_ERR(channel))
1386                         return PTR_ERR(channel);
1387
1388                 /* The opening dance was initiated by the remote */
1389                 create_device = true;
1390         }
1391
1392         spin_lock_irqsave(&glink->idr_lock, flags);
1393         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1394         if (ret < 0) {
1395                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1396                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1397                 goto free_channel;
1398         }
1399         channel->rcid = ret;
1400         spin_unlock_irqrestore(&glink->idr_lock, flags);
1401
1402         complete(&channel->open_req);
1403
1404         if (create_device) {
1405                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1406                 if (!rpdev) {
1407                         ret = -ENOMEM;
1408                         goto rcid_remove;
1409                 }
1410
1411                 rpdev->ept = &channel->ept;
1412                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1413                 rpdev->src = RPMSG_ADDR_ANY;
1414                 rpdev->dst = RPMSG_ADDR_ANY;
1415                 rpdev->ops = &glink_device_ops;
1416
1417                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1418                 rpdev->dev.of_node = node;
1419                 rpdev->dev.parent = glink->dev;
1420                 rpdev->dev.release = qcom_glink_rpdev_release;
1421
1422                 ret = rpmsg_register_device(rpdev);
1423                 if (ret)
1424                         goto free_rpdev;
1425
1426                 channel->rpdev = rpdev;
1427         }
1428
1429         return 0;
1430
1431 free_rpdev:
1432         kfree(rpdev);
1433 rcid_remove:
1434         spin_lock_irqsave(&glink->idr_lock, flags);
1435         idr_remove(&glink->rcids, channel->rcid);
1436         channel->rcid = 0;
1437         spin_unlock_irqrestore(&glink->idr_lock, flags);
1438 free_channel:
1439         /* Release the reference, iff we took it */
1440         if (create_device)
1441                 kref_put(&channel->refcount, qcom_glink_channel_release);
1442
1443         return ret;
1444 }
1445
1446 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1447 {
1448         struct rpmsg_channel_info chinfo;
1449         struct glink_channel *channel;
1450         unsigned long flags;
1451
1452         spin_lock_irqsave(&glink->idr_lock, flags);
1453         channel = idr_find(&glink->rcids, rcid);
1454         spin_unlock_irqrestore(&glink->idr_lock, flags);
1455         if (WARN(!channel, "close request on unknown channel\n"))
1456                 return;
1457
1458         /* cancel pending rx_done work */
1459         cancel_work_sync(&channel->intent_work);
1460
1461         if (channel->rpdev) {
1462                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1463                 chinfo.src = RPMSG_ADDR_ANY;
1464                 chinfo.dst = RPMSG_ADDR_ANY;
1465
1466                 rpmsg_unregister_device(glink->dev, &chinfo);
1467         }
1468
1469         qcom_glink_send_close_ack(glink, channel->rcid);
1470
1471         spin_lock_irqsave(&glink->idr_lock, flags);
1472         idr_remove(&glink->rcids, channel->rcid);
1473         channel->rcid = 0;
1474         spin_unlock_irqrestore(&glink->idr_lock, flags);
1475
1476         kref_put(&channel->refcount, qcom_glink_channel_release);
1477 }
1478
1479 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1480 {
1481         struct glink_channel *channel;
1482         unsigned long flags;
1483
1484         spin_lock_irqsave(&glink->idr_lock, flags);
1485         channel = idr_find(&glink->lcids, lcid);
1486         if (WARN(!channel, "close ack on unknown channel\n")) {
1487                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1488                 return;
1489         }
1490
1491         idr_remove(&glink->lcids, channel->lcid);
1492         channel->lcid = 0;
1493         spin_unlock_irqrestore(&glink->idr_lock, flags);
1494
1495         kref_put(&channel->refcount, qcom_glink_channel_release);
1496 }
1497
1498 static void qcom_glink_work(struct work_struct *work)
1499 {
1500         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1501                                                 rx_work);
1502         struct glink_defer_cmd *dcmd;
1503         struct glink_msg *msg;
1504         unsigned long flags;
1505         unsigned int param1;
1506         unsigned int param2;
1507         unsigned int cmd;
1508
1509         for (;;) {
1510                 spin_lock_irqsave(&glink->rx_lock, flags);
1511                 if (list_empty(&glink->rx_queue)) {
1512                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1513                         break;
1514                 }
1515                 dcmd = list_first_entry(&glink->rx_queue,
1516                                         struct glink_defer_cmd, node);
1517                 list_del(&dcmd->node);
1518                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1519
1520                 msg = &dcmd->msg;
1521                 cmd = le16_to_cpu(msg->cmd);
1522                 param1 = le16_to_cpu(msg->param1);
1523                 param2 = le32_to_cpu(msg->param2);
1524
1525                 switch (cmd) {
1526                 case RPM_CMD_VERSION:
1527                         qcom_glink_receive_version(glink, param1, param2);
1528                         break;
1529                 case RPM_CMD_VERSION_ACK:
1530                         qcom_glink_receive_version_ack(glink, param1, param2);
1531                         break;
1532                 case RPM_CMD_OPEN:
1533                         qcom_glink_rx_open(glink, param1, msg->data);
1534                         break;
1535                 case RPM_CMD_CLOSE:
1536                         qcom_glink_rx_close(glink, param1);
1537                         break;
1538                 case RPM_CMD_CLOSE_ACK:
1539                         qcom_glink_rx_close_ack(glink, param1);
1540                         break;
1541                 case RPM_CMD_RX_INTENT_REQ:
1542                         qcom_glink_handle_intent_req(glink, param1, param2);
1543                         break;
1544                 default:
1545                         WARN(1, "Unknown defer object %d\n", cmd);
1546                         break;
1547                 }
1548
1549                 kfree(dcmd);
1550         }
1551 }
1552
1553 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1554                                            unsigned long features,
1555                                            struct qcom_glink_pipe *rx,
1556                                            struct qcom_glink_pipe *tx,
1557                                            bool intentless)
1558 {
1559         int irq;
1560         int ret;
1561         struct qcom_glink *glink;
1562
1563         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1564         if (!glink)
1565                 return ERR_PTR(-ENOMEM);
1566
1567         glink->dev = dev;
1568         glink->tx_pipe = tx;
1569         glink->rx_pipe = rx;
1570
1571         glink->features = features;
1572         glink->intentless = intentless;
1573
1574         spin_lock_init(&glink->tx_lock);
1575         spin_lock_init(&glink->rx_lock);
1576         INIT_LIST_HEAD(&glink->rx_queue);
1577         INIT_WORK(&glink->rx_work, qcom_glink_work);
1578
1579         spin_lock_init(&glink->idr_lock);
1580         idr_init(&glink->lcids);
1581         idr_init(&glink->rcids);
1582
1583         glink->mbox_client.dev = dev;
1584         glink->mbox_client.knows_txdone = true;
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         unsigned long flags;
1625
1626         disable_irq(glink->irq);
1627         cancel_work_sync(&glink->rx_work);
1628
1629         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1630         if (ret)
1631                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1632
1633         spin_lock_irqsave(&glink->idr_lock, flags);
1634         /* Release any defunct local channels, waiting for close-ack */
1635         idr_for_each_entry(&glink->lcids, channel, cid)
1636                 kref_put(&channel->refcount, qcom_glink_channel_release);
1637
1638         idr_destroy(&glink->lcids);
1639         idr_destroy(&glink->rcids);
1640         spin_unlock_irqrestore(&glink->idr_lock, flags);
1641         mbox_free_channel(glink->mbox_chan);
1642 }
1643 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1644
1645 void qcom_glink_native_unregister(struct qcom_glink *glink)
1646 {
1647         device_unregister(glink->dev);
1648 }
1649 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1650
1651 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1652 MODULE_LICENSE("GPL v2");