drivers/rpmsg/qcom_glink_native.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016-2017, Linaro Ltd
   4  */
   5
   6 #include <linux/idr.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/list.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/of_address.h>
  14 #include <linux/of_irq.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17 #include <linux/rpmsg.h>
  18 #include <linux/sizes.h>
  19 #include <linux/slab.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/mailbox_client.h>
  22
  23 #include "rpmsg_internal.h"
  24 #include "qcom_glink_native.h"
  25
  26 #define GLINK_NAME_SIZE         32
  27 #define GLINK_VERSION_1         1
  28
  29 #define RPM_GLINK_CID_MIN       1
  30 #define RPM_GLINK_CID_MAX       65536
  31
  32 struct glink_msg {
  33         __le16 cmd;
  34         __le16 param1;
  35         __le32 param2;
  36         u8 data[];
  37 } __packed;
  38
  39 /**
  40  * struct glink_defer_cmd - deferred incoming control message
  41  * @node:       list node
  42  * @msg:        message header
  43  * @data:       payload of the message
  44  *
  45  * Copy of a received control message, to be added to @rx_queue and processed
  46  * by @rx_work of @qcom_glink.
  47  */
  48 struct glink_defer_cmd {
  49         struct list_head node;
  50
  51         struct glink_msg msg;
  52         u8 data[];
  53 };
  54
  55 /**
  56  * struct glink_core_rx_intent - RX intent
  57  * RX intent
  58  *
  59  * @data: pointer to the data (may be NULL for zero-copy)
  60  * @id: remote or local intent ID
  61  * @size: size of the original intent (do not modify)
  62  * @reuse: To mark if the intent can be reused after first use
  63  * @in_use: To mark if intent is already in use for the channel
  64  * @offset: next write offset (initially 0)
  65  * @node:       list node
  66  */
  67 struct glink_core_rx_intent {
  68         void *data;
  69         u32 id;
  70         size_t size;
  71         bool reuse;
  72         bool in_use;
  73         u32 offset;
  74
  75         struct list_head node;
  76 };
  77
  78 /**
  79  * struct qcom_glink - driver context, relates to one remote subsystem
  80  * @dev:        reference to the associated struct device
  81  * @mbox_client: mailbox client
  82  * @mbox_chan:  mailbox channel
  83  * @rx_pipe:    pipe object for receive FIFO
  84  * @tx_pipe:    pipe object for transmit FIFO
  85  * @irq:        IRQ for signaling incoming events
  86  * @rx_work:    worker for handling received control messages
  87  * @rx_lock:    protects the @rx_queue
  88  * @rx_queue:   queue of received control messages to be processed in @rx_work
  89  * @tx_lock:    synchronizes operations on the tx fifo
  90  * @idr_lock:   synchronizes @lcids and @rcids modifications
  91  * @lcids:      idr of all channels with a known local channel id
  92  * @rcids:      idr of all channels with a known remote channel id
  93  * @features:   remote features
  94  * @intentless: flag to indicate that there is no intent
  95  */
  96 struct qcom_glink {
  97         struct device *dev;
  98
  99         const char *name;
 100
 101         struct mbox_client mbox_client;
 102         struct mbox_chan *mbox_chan;
 103
 104         struct qcom_glink_pipe *rx_pipe;
 105         struct qcom_glink_pipe *tx_pipe;
 106
 107         int irq;
 108
 109         struct work_struct rx_work;
 110         spinlock_t rx_lock;
 111         struct list_head rx_queue;
 112
 113         spinlock_t tx_lock;
 114
 115         spinlock_t idr_lock;
 116         struct idr lcids;
 117         struct idr rcids;
 118         unsigned long features;
 119
 120         bool intentless;
 121 };
 122
 123 enum {
 124         GLINK_STATE_CLOSED,
 125         GLINK_STATE_OPENING,
 126         GLINK_STATE_OPEN,
 127         GLINK_STATE_CLOSING,
 128 };
 129
 130 /**
 131  * struct glink_channel - internal representation of a channel
 132  * @rpdev:      rpdev reference, only used for primary endpoints
 133  * @ept:        rpmsg endpoint this channel is associated with
 134  * @glink:      qcom_glink context handle
 135  * @refcount:   refcount for the channel object
 136  * @recv_lock:  guard for @ept.cb
 137  * @name:       unique channel name/identifier
 138  * @lcid:       channel id, in local space
 139  * @rcid:       channel id, in remote space
 140  * @intent_lock: lock for protection of @liids, @riids
 141  * @liids:      idr of all local intents
 142  * @riids:      idr of all remote intents
 143  * @intent_work: worker responsible for transmitting rx_done packets
 144  * @done_intents: list of intents that needs to be announced rx_done
 145  * @buf:        receive buffer, for gathering fragments
 146  * @buf_offset: write offset in @buf
 147  * @buf_size:   size of current @buf
 148  * @open_ack:   completed once remote has acked the open-request
 149  * @open_req:   completed once open-request has been received
 150  * @intent_req_lock: Synchronises multiple intent requests
 151  * @intent_req_result: Result of intent request
 152  * @intent_req_comp: Completion for intent_req signalling
 153  */
 154 struct glink_channel {
 155         struct rpmsg_endpoint ept;
 156
 157         struct rpmsg_device *rpdev;
 158         struct qcom_glink *glink;
 159
 160         struct kref refcount;
 161
 162         spinlock_t recv_lock;
 163
 164         char *name;
 165         unsigned int lcid;
 166         unsigned int rcid;
 167
 168         spinlock_t intent_lock;
 169         struct idr liids;
 170         struct idr riids;
 171         struct work_struct intent_work;
 172         struct list_head done_intents;
 173
 174         struct glink_core_rx_intent *buf;
 175         int buf_offset;
 176         int buf_size;
 177
 178         struct completion open_ack;
 179         struct completion open_req;
 180
 181         struct mutex intent_req_lock;
 182         bool intent_req_result;
 183         struct completion intent_req_comp;
 184 };
 185
 186 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 187
 188 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 189
 190 #define RPM_CMD_VERSION                 0
 191 #define RPM_CMD_VERSION_ACK             1
 192 #define RPM_CMD_OPEN                    2
 193 #define RPM_CMD_CLOSE                   3
 194 #define RPM_CMD_OPEN_ACK                4
 195 #define RPM_CMD_INTENT                  5
 196 #define RPM_CMD_RX_DONE                 6
 197 #define RPM_CMD_RX_INTENT_REQ           7
 198 #define RPM_CMD_RX_INTENT_REQ_ACK       8
 199 #define RPM_CMD_TX_DATA                 9
 200 #define RPM_CMD_CLOSE_ACK               11
 201 #define RPM_CMD_TX_DATA_CONT            12
 202 #define RPM_CMD_READ_NOTIF              13
 203 #define RPM_CMD_RX_DONE_W_REUSE         14
 204
 205 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 206
 207 static void qcom_glink_rx_done_work(struct work_struct *work);
 208
 209 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 210                                                       const char *name)
 211 {
 212         struct glink_channel *channel;
 213
 214         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 215         if (!channel)
 216                 return ERR_PTR(-ENOMEM);
 217
 218         /* Setup glink internal glink_channel data */
 219         spin_lock_init(&channel->recv_lock);
 220         spin_lock_init(&channel->intent_lock);
 221         mutex_init(&channel->intent_req_lock);
 222
 223         channel->glink = glink;
 224         channel->name = kstrdup(name, GFP_KERNEL);
 225
 226         init_completion(&channel->open_req);
 227         init_completion(&channel->open_ack);
 228         init_completion(&channel->intent_req_comp);
 229
 230         INIT_LIST_HEAD(&channel->done_intents);
 231         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 232
 233         idr_init(&channel->liids);
 234         idr_init(&channel->riids);
 235         kref_init(&channel->refcount);
 236
 237         return channel;
 238 }
 239
 240 static void qcom_glink_channel_release(struct kref *ref)
 241 {
 242         struct glink_channel *channel = container_of(ref, struct glink_channel,
 243                                                      refcount);
 244         unsigned long flags;
 245
 246         spin_lock_irqsave(&channel->intent_lock, flags);
 247         idr_destroy(&channel->liids);
 248         idr_destroy(&channel->riids);
 249         spin_unlock_irqrestore(&channel->intent_lock, flags);
 250
 251         kfree(channel->name);
 252         kfree(channel);
 253 }
 254
 255 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 256 {
 257         return glink->rx_pipe->avail(glink->rx_pipe);
 258 }
 259
 260 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 261                                void *data, unsigned int offset, size_t count)
 262 {
 263         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 264 }
 265
 266 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 267 {
 268         glink->rx_pipe->advance(glink->rx_pipe, count);
 269 }
 270
 271 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 272 {
 273         return glink->tx_pipe->avail(glink->tx_pipe);
 274 }
 275
 276 static void qcom_glink_tx_write(struct qcom_glink *glink,
 277                                 const void *hdr, size_t hlen,
 278                                 const void *data, size_t dlen)
 279 {
 280         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 281 }
 282
 283 static int qcom_glink_tx(struct qcom_glink *glink,
 284                          const void *hdr, size_t hlen,
 285                          const void *data, size_t dlen, bool wait)
 286 {
 287         unsigned int tlen = hlen + dlen;
 288         unsigned long flags;
 289         int ret = 0;
 290
 291         /* Reject packets that are too big */
 292         if (tlen >= glink->tx_pipe->length)
 293                 return -EINVAL;
 294
 295         spin_lock_irqsave(&glink->tx_lock, flags);
 296
 297         while (qcom_glink_tx_avail(glink) < tlen) {
 298                 if (!wait) {
 299                         ret = -EAGAIN;
 300                         goto out;
 301                 }
 302
 303                 /* Wait without holding the tx_lock */
 304                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 305
 306                 usleep_range(10000, 15000);
 307
 308                 spin_lock_irqsave(&glink->tx_lock, flags);
 309         }
 310
 311         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 312
 313         mbox_send_message(glink->mbox_chan, NULL);
 314         mbox_client_txdone(glink->mbox_chan, 0);
 315
 316 out:
 317         spin_unlock_irqrestore(&glink->tx_lock, flags);
 318
 319         return ret;
 320 }
 321
 322 static int qcom_glink_send_version(struct qcom_glink *glink)
 323 {
 324         struct glink_msg msg;
 325
 326         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 327         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 328         msg.param2 = cpu_to_le32(glink->features);
 329
 330         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 331 }
 332
 333 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 334 {
 335         struct glink_msg msg;
 336
 337         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 338         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 339         msg.param2 = cpu_to_le32(glink->features);
 340
 341         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 342 }
 343
 344 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 345                                      struct glink_channel *channel)
 346 {
 347         struct glink_msg msg;
 348
 349         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 350         msg.param1 = cpu_to_le16(channel->rcid);
 351         msg.param2 = cpu_to_le32(0);
 352
 353         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 354 }
 355
 356 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 357                                              unsigned int cid, bool granted)
 358 {
 359         struct glink_channel *channel;
 360         unsigned long flags;
 361
 362         spin_lock_irqsave(&glink->idr_lock, flags);
 363         channel = idr_find(&glink->rcids, cid);
 364         spin_unlock_irqrestore(&glink->idr_lock, flags);
 365         if (!channel) {
 366                 dev_err(glink->dev, "unable to find channel\n");
 367                 return;
 368         }
 369
 370         channel->intent_req_result = granted;
 371         complete(&channel->intent_req_comp);
 372 }
 373
 374 /**
 375  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 376  * @glink: Ptr to the glink edge
 377  * @channel: Ptr to the channel that the open req is sent
 378  *
 379  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 380  * Will return with refcount held, regardless of outcome.
 381  *
 382  * Returns 0 on success, negative errno otherwise.
 383  */
 384 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 385                                     struct glink_channel *channel)
 386 {
 387         struct {
 388                 struct glink_msg msg;
 389                 u8 name[GLINK_NAME_SIZE];
 390         } __packed req;
 391         int name_len = strlen(channel->name) + 1;
 392         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 393         int ret;
 394         unsigned long flags;
 395
 396         kref_get(&channel->refcount);
 397
 398         spin_lock_irqsave(&glink->idr_lock, flags);
 399         ret = idr_alloc_cyclic(&glink->lcids, channel,
 400                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 401                                GFP_ATOMIC);
 402         spin_unlock_irqrestore(&glink->idr_lock, flags);
 403         if (ret < 0)
 404                 return ret;
 405
 406         channel->lcid = ret;
 407
 408         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 409         req.msg.param1 = cpu_to_le16(channel->lcid);
 410         req.msg.param2 = cpu_to_le32(name_len);
 411         strcpy(req.name, channel->name);
 412
 413         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 414         if (ret)
 415                 goto remove_idr;
 416
 417         return 0;
 418
 419 remove_idr:
 420         spin_lock_irqsave(&glink->idr_lock, flags);
 421         idr_remove(&glink->lcids, channel->lcid);
 422         channel->lcid = 0;
 423         spin_unlock_irqrestore(&glink->idr_lock, flags);
 424
 425         return ret;
 426 }
 427
 428 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 429                                       struct glink_channel *channel)
 430 {
 431         struct glink_msg req;
 432
 433         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 434         req.param1 = cpu_to_le16(channel->lcid);
 435         req.param2 = 0;
 436
 437         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 438 }
 439
 440 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 441                                       unsigned int rcid)
 442 {
 443         struct glink_msg req;
 444
 445         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 446         req.param1 = cpu_to_le16(rcid);
 447         req.param2 = 0;
 448
 449         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 450 }
 451
 452 static void qcom_glink_rx_done_work(struct work_struct *work)
 453 {
 454         struct glink_channel *channel = container_of(work, struct glink_channel,
 455                                                      intent_work);
 456         struct qcom_glink *glink = channel->glink;
 457         struct glink_core_rx_intent *intent, *tmp;
 458         struct {
 459                 u16 id;
 460                 u16 lcid;
 461                 u32 liid;
 462         } __packed cmd;
 463
 464         unsigned int cid = channel->lcid;
 465         unsigned int iid;
 466         bool reuse;
 467         unsigned long flags;
 468
 469         spin_lock_irqsave(&channel->intent_lock, flags);
 470         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 471                 list_del(&intent->node);
 472                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 473                 iid = intent->id;
 474                 reuse = intent->reuse;
 475
 476                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 477                 cmd.lcid = cid;
 478                 cmd.liid = iid;
 479
 480                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 481                 if (!reuse) {
 482                         kfree(intent->data);
 483                         kfree(intent);
 484                 }
 485                 spin_lock_irqsave(&channel->intent_lock, flags);
 486         }
 487         spin_unlock_irqrestore(&channel->intent_lock, flags);
 488 }
 489
 490 static void qcom_glink_rx_done(struct qcom_glink *glink,
 491                                struct glink_channel *channel,
 492                                struct glink_core_rx_intent *intent)
 493 {
 494         /* We don't send RX_DONE to intentless systems */
 495         if (glink->intentless) {
 496                 kfree(intent->data);
 497                 kfree(intent);
 498                 return;
 499         }
 500
 501         /* Take it off the tree of receive intents */
 502         if (!intent->reuse) {
 503                 spin_lock(&channel->intent_lock);
 504                 idr_remove(&channel->liids, intent->id);
 505                 spin_unlock(&channel->intent_lock);
 506         }
 507
 508         /* Schedule the sending of a rx_done indication */
 509         spin_lock(&channel->intent_lock);
 510         list_add_tail(&intent->node, &channel->done_intents);
 511         spin_unlock(&channel->intent_lock);
 512
 513         schedule_work(&channel->intent_work);
 514 }
 515
 516 /**
 517  * qcom_glink_receive_version() - receive version/features from remote system
 518  *
 519  * @glink:      pointer to transport interface
 520  * @version:    remote version
 521  * @features:   remote features
 522  *
 523  * This function is called in response to a remote-initiated version/feature
 524  * negotiation sequence.
 525  */
 526 static void qcom_glink_receive_version(struct qcom_glink *glink,
 527                                        u32 version,
 528                                        u32 features)
 529 {
 530         switch (version) {
 531         case 0:
 532                 break;
 533         case GLINK_VERSION_1:
 534                 glink->features &= features;
 535                 /* FALLTHROUGH */
 536         default:
 537                 qcom_glink_send_version_ack(glink);
 538                 break;
 539         }
 540 }
 541
 542 /**
 543  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 544  *
 545  * @glink:      pointer to transport interface
 546  * @version:    remote version response
 547  * @features:   remote features response
 548  *
 549  * This function is called in response to a local-initiated version/feature
 550  * negotiation sequence and is the counter-offer from the remote side based
 551  * upon the initial version and feature set requested.
 552  */
 553 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 554                                            u32 version,
 555                                            u32 features)
 556 {
 557         switch (version) {
 558         case 0:
 559                 /* Version negotiation failed */
 560                 break;
 561         case GLINK_VERSION_1:
 562                 if (features == glink->features)
 563                         break;
 564
 565                 glink->features &= features;
 566                 /* FALLTHROUGH */
 567         default:
 568                 qcom_glink_send_version(glink);
 569                 break;
 570         }
 571 }
 572
 573 /**
 574  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 575  *      wire format and transmit
 576  * @glink:      The transport to transmit on.
 577  * @channel:    The glink channel
 578  * @granted:    The request response to encode.
 579  *
 580  * Return: 0 on success or standard Linux error code.
 581  */
 582 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 583                                           struct glink_channel *channel,
 584                                           bool granted)
 585 {
 586         struct glink_msg msg;
 587
 588         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 589         msg.param1 = cpu_to_le16(channel->lcid);
 590         msg.param2 = cpu_to_le32(granted);
 591
 592         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 593
 594         return 0;
 595 }
 596
 597 /**
 598  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 599  *                         transmit
 600  * @glink:      The transport to transmit on.
 601  * @channel:    The local channel
 602  * @intent:     The intent to pass on to remote.
 603  *
 604  * Return: 0 on success or standard Linux error code.
 605  */
 606 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 607                                        struct glink_channel *channel,
 608                                        struct glink_core_rx_intent *intent)
 609 {
 610         struct command {
 611                 __le16 id;
 612                 __le16 lcid;
 613                 __le32 count;
 614                 __le32 size;
 615                 __le32 liid;
 616         } __packed;
 617         struct command cmd;
 618
 619         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 620         cmd.lcid = cpu_to_le16(channel->lcid);
 621         cmd.count = cpu_to_le32(1);
 622         cmd.size = cpu_to_le32(intent->size);
 623         cmd.liid = cpu_to_le32(intent->id);
 624
 625         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 626
 627         return 0;
 628 }
 629
 630 static struct glink_core_rx_intent *
 631 qcom_glink_alloc_intent(struct qcom_glink *glink,
 632                         struct glink_channel *channel,
 633                         size_t size,
 634                         bool reuseable)
 635 {
 636         struct glink_core_rx_intent *intent;
 637         int ret;
 638         unsigned long flags;
 639
 640         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 641         if (!intent)
 642                 return NULL;
 643
 644         intent->data = kzalloc(size, GFP_KERNEL);
 645         if (!intent->data)
 646                 goto free_intent;
 647
 648         spin_lock_irqsave(&channel->intent_lock, flags);
 649         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 650         if (ret < 0) {
 651                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 652                 goto free_data;
 653         }
 654         spin_unlock_irqrestore(&channel->intent_lock, flags);
 655
 656         intent->id = ret;
 657         intent->size = size;
 658         intent->reuse = reuseable;
 659
 660         return intent;
 661
 662 free_data:
 663         kfree(intent->data);
 664 free_intent:
 665         kfree(intent);
 666         return NULL;
 667 }
 668
 669 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 670                                       u32 cid, uint32_t iid,
 671                                       bool reuse)
 672 {
 673         struct glink_core_rx_intent *intent;
 674         struct glink_channel *channel;
 675         unsigned long flags;
 676
 677         spin_lock_irqsave(&glink->idr_lock, flags);
 678         channel = idr_find(&glink->rcids, cid);
 679         spin_unlock_irqrestore(&glink->idr_lock, flags);
 680         if (!channel) {
 681                 dev_err(glink->dev, "invalid channel id received\n");
 682                 return;
 683         }
 684
 685         spin_lock_irqsave(&channel->intent_lock, flags);
 686         intent = idr_find(&channel->riids, iid);
 687
 688         if (!intent) {
 689                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 690                 dev_err(glink->dev, "invalid intent id received\n");
 691                 return;
 692         }
 693
 694         intent->in_use = false;
 695
 696         if (!reuse) {
 697                 idr_remove(&channel->riids, intent->id);
 698                 kfree(intent);
 699         }
 700         spin_unlock_irqrestore(&channel->intent_lock, flags);
 701 }
 702
 703 /**
 704  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 705  *                                          from remote side
 706  * @glink:      Pointer to the transport interface
 707  * @cid:        Remote channel ID
 708  * @size:       size of the intent
 709  *
 710  * The function searches for the local channel to which the request for
 711  * rx_intent has arrived and allocates and notifies the remote back
 712  */
 713 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 714                                          u32 cid, size_t size)
 715 {
 716         struct glink_core_rx_intent *intent;
 717         struct glink_channel *channel;
 718         unsigned long flags;
 719
 720         spin_lock_irqsave(&glink->idr_lock, flags);
 721         channel = idr_find(&glink->rcids, cid);
 722         spin_unlock_irqrestore(&glink->idr_lock, flags);
 723
 724         if (!channel) {
 725                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 726                 return;
 727         }
 728
 729         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 730         if (intent)
 731                 qcom_glink_advertise_intent(glink, channel, intent);
 732
 733         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 734 }
 735
 736 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 737 {
 738         struct glink_defer_cmd *dcmd;
 739
 740         extra = ALIGN(extra, 8);
 741
 742         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 743                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 744                 return -ENXIO;
 745         }
 746
 747         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 748         if (!dcmd)
 749                 return -ENOMEM;
 750
 751         INIT_LIST_HEAD(&dcmd->node);
 752
 753         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 754
 755         spin_lock(&glink->rx_lock);
 756         list_add_tail(&dcmd->node, &glink->rx_queue);
 757         spin_unlock(&glink->rx_lock);
 758
 759         schedule_work(&glink->rx_work);
 760         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 761
 762         return 0;
 763 }
 764
 765 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 766 {
 767         struct glink_core_rx_intent *intent;
 768         struct glink_channel *channel;
 769         struct {
 770                 struct glink_msg msg;
 771                 __le32 chunk_size;
 772                 __le32 left_size;
 773         } __packed hdr;
 774         unsigned int chunk_size;
 775         unsigned int left_size;
 776         unsigned int rcid;
 777         unsigned int liid;
 778         int ret = 0;
 779         unsigned long flags;
 780
 781         if (avail < sizeof(hdr)) {
 782                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 783                 return -EAGAIN;
 784         }
 785
 786         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 787         chunk_size = le32_to_cpu(hdr.chunk_size);
 788         left_size = le32_to_cpu(hdr.left_size);
 789
 790         if (avail < sizeof(hdr) + chunk_size) {
 791                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 792                 return -EAGAIN;
 793         }
 794
 795         rcid = le16_to_cpu(hdr.msg.param1);
 796         spin_lock_irqsave(&glink->idr_lock, flags);
 797         channel = idr_find(&glink->rcids, rcid);
 798         spin_unlock_irqrestore(&glink->idr_lock, flags);
 799         if (!channel) {
 800                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 801
 802                 /* Drop the message */
 803                 goto advance_rx;
 804         }
 805
 806         if (glink->intentless) {
 807                 /* Might have an ongoing, fragmented, message to append */
 808                 if (!channel->buf) {
 809                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 810                         if (!intent)
 811                                 return -ENOMEM;
 812
 813                         intent->data = kmalloc(chunk_size + left_size,
 814                                                GFP_ATOMIC);
 815                         if (!intent->data) {
 816                                 kfree(intent);
 817                                 return -ENOMEM;
 818                         }
 819
 820                         intent->id = 0xbabababa;
 821                         intent->size = chunk_size + left_size;
 822                         intent->offset = 0;
 823
 824                         channel->buf = intent;
 825                 } else {
 826                         intent = channel->buf;
 827                 }
 828         } else {
 829                 liid = le32_to_cpu(hdr.msg.param2);
 830
 831                 spin_lock_irqsave(&channel->intent_lock, flags);
 832                 intent = idr_find(&channel->liids, liid);
 833                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 834
 835                 if (!intent) {
 836                         dev_err(glink->dev,
 837                                 "no intent found for channel %s intent %d",
 838                                 channel->name, liid);
 839                         goto advance_rx;
 840                 }
 841         }
 842
 843         if (intent->size - intent->offset < chunk_size) {
 844                 dev_err(glink->dev, "Insufficient space in intent\n");
 845
 846                 /* The packet header lied, drop payload */
 847                 goto advance_rx;
 848         }
 849
 850         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 851                            sizeof(hdr), chunk_size);
 852         intent->offset += chunk_size;
 853
 854         /* Handle message when no fragments remain to be received */
 855         if (!left_size) {
 856                 spin_lock(&channel->recv_lock);
 857                 if (channel->ept.cb) {
 858                         channel->ept.cb(channel->ept.rpdev,
 859                                         intent->data,
 860                                         intent->offset,
 861                                         channel->ept.priv,
 862                                         RPMSG_ADDR_ANY);
 863                 }
 864                 spin_unlock(&channel->recv_lock);
 865
 866                 intent->offset = 0;
 867                 channel->buf = NULL;
 868
 869                 qcom_glink_rx_done(glink, channel, intent);
 870         }
 871
 872 advance_rx:
 873         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 874
 875         return ret;
 876 }
 877
 878 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 879                                      unsigned int cid,
 880                                      unsigned int count,
 881                                      size_t avail)
 882 {
 883         struct glink_core_rx_intent *intent;
 884         struct glink_channel *channel;
 885         struct intent_pair {
 886                 __le32 size;
 887                 __le32 iid;
 888         };
 889
 890         struct {
 891                 struct glink_msg msg;
 892                 struct intent_pair intents[];
 893         } __packed * msg;
 894
 895         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
 896         int ret;
 897         int i;
 898         unsigned long flags;
 899
 900         if (avail < msglen) {
 901                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 902                 return;
 903         }
 904
 905         spin_lock_irqsave(&glink->idr_lock, flags);
 906         channel = idr_find(&glink->rcids, cid);
 907         spin_unlock_irqrestore(&glink->idr_lock, flags);
 908         if (!channel) {
 909                 dev_err(glink->dev, "intents for non-existing channel\n");
 910                 return;
 911         }
 912
 913         msg = kmalloc(msglen, GFP_ATOMIC);
 914         if (!msg)
 915                 return;
 916
 917         qcom_glink_rx_peak(glink, msg, 0, msglen);
 918
 919         for (i = 0; i < count; ++i) {
 920                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 921                 if (!intent)
 922                         break;
 923
 924                 intent->id = le32_to_cpu(msg->intents[i].iid);
 925                 intent->size = le32_to_cpu(msg->intents[i].size);
 926
 927                 spin_lock_irqsave(&channel->intent_lock, flags);
 928                 ret = idr_alloc(&channel->riids, intent,
 929                                 intent->id, intent->id + 1, GFP_ATOMIC);
 930                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 931
 932                 if (ret < 0)
 933                         dev_err(glink->dev, "failed to store remote intent\n");
 934         }
 935
 936         kfree(msg);
 937         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 938 }
 939
 940 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 941 {
 942         struct glink_channel *channel;
 943
 944         spin_lock(&glink->idr_lock);
 945         channel = idr_find(&glink->lcids, lcid);
 946         spin_unlock(&glink->idr_lock);
 947         if (!channel) {
 948                 dev_err(glink->dev, "Invalid open ack packet\n");
 949                 return -EINVAL;
 950         }
 951
 952         complete(&channel->open_ack);
 953
 954         return 0;
 955 }
 956
 957 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 958 {
 959         struct qcom_glink *glink = data;
 960         struct glink_msg msg;
 961         unsigned int param1;
 962         unsigned int param2;
 963         unsigned int avail;
 964         unsigned int cmd;
 965         int ret = 0;
 966
 967         for (;;) {
 968                 avail = qcom_glink_rx_avail(glink);
 969                 if (avail < sizeof(msg))
 970                         break;
 971
 972                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 973
 974                 cmd = le16_to_cpu(msg.cmd);
 975                 param1 = le16_to_cpu(msg.param1);
 976                 param2 = le32_to_cpu(msg.param2);
 977
 978                 switch (cmd) {
 979                 case RPM_CMD_VERSION:
 980                 case RPM_CMD_VERSION_ACK:
 981                 case RPM_CMD_CLOSE:
 982                 case RPM_CMD_CLOSE_ACK:
 983                 case RPM_CMD_RX_INTENT_REQ:
 984                         ret = qcom_glink_rx_defer(glink, 0);
 985                         break;
 986                 case RPM_CMD_OPEN_ACK:
 987                         ret = qcom_glink_rx_open_ack(glink, param1);
 988                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 989                         break;
 990                 case RPM_CMD_OPEN:
 991                         ret = qcom_glink_rx_defer(glink, param2);
 992                         break;
 993                 case RPM_CMD_TX_DATA:
 994                 case RPM_CMD_TX_DATA_CONT:
 995                         ret = qcom_glink_rx_data(glink, avail);
 996                         break;
 997                 case RPM_CMD_READ_NOTIF:
 998                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 999
1000                         mbox_send_message(glink->mbox_chan, NULL);
1001                         mbox_client_txdone(glink->mbox_chan, 0);
1002                         break;
1003                 case RPM_CMD_INTENT:
1004                         qcom_glink_handle_intent(glink, param1, param2, avail);
1005                         break;
1006                 case RPM_CMD_RX_DONE:
1007                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1008                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1009                         break;
1010                 case RPM_CMD_RX_DONE_W_REUSE:
1011                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1012                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1013                         break;
1014                 case RPM_CMD_RX_INTENT_REQ_ACK:
1015                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1016                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1017                         break;
1018                 default:
1019                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1020                         ret = -EINVAL;
1021                         break;
1022                 }
1023
1024                 if (ret)
1025                         break;
1026         }
1027
1028         return IRQ_HANDLED;
1029 }
1030
1031 /* Locally initiated rpmsg_create_ept */
1032 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1033                                                      const char *name)
1034 {
1035         struct glink_channel *channel;
1036         int ret;
1037         unsigned long flags;
1038
1039         channel = qcom_glink_alloc_channel(glink, name);
1040         if (IS_ERR(channel))
1041                 return ERR_CAST(channel);
1042
1043         ret = qcom_glink_send_open_req(glink, channel);
1044         if (ret)
1045                 goto release_channel;
1046
1047         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1048         if (!ret)
1049                 goto err_timeout;
1050
1051         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1052         if (!ret)
1053                 goto err_timeout;
1054
1055         qcom_glink_send_open_ack(glink, channel);
1056
1057         return channel;
1058
1059 err_timeout:
1060         /* qcom_glink_send_open_req() did register the channel in lcids*/
1061         spin_lock_irqsave(&glink->idr_lock, flags);
1062         idr_remove(&glink->lcids, channel->lcid);
1063         spin_unlock_irqrestore(&glink->idr_lock, flags);
1064
1065 release_channel:
1066         /* Release qcom_glink_send_open_req() reference */
1067         kref_put(&channel->refcount, qcom_glink_channel_release);
1068         /* Release qcom_glink_alloc_channel() reference */
1069         kref_put(&channel->refcount, qcom_glink_channel_release);
1070
1071         return ERR_PTR(-ETIMEDOUT);
1072 }
1073
1074 /* Remote initiated rpmsg_create_ept */
1075 static int qcom_glink_create_remote(struct qcom_glink *glink,
1076                                     struct glink_channel *channel)
1077 {
1078         int ret;
1079
1080         qcom_glink_send_open_ack(glink, channel);
1081
1082         ret = qcom_glink_send_open_req(glink, channel);
1083         if (ret)
1084                 goto close_link;
1085
1086         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1087         if (!ret) {
1088                 ret = -ETIMEDOUT;
1089                 goto close_link;
1090         }
1091
1092         return 0;
1093
1094 close_link:
1095         /*
1096          * Send a close request to "undo" our open-ack. The close-ack will
1097          * release the last reference.
1098          */
1099         qcom_glink_send_close_req(glink, channel);
1100
1101         /* Release qcom_glink_send_open_req() reference */
1102         kref_put(&channel->refcount, qcom_glink_channel_release);
1103
1104         return ret;
1105 }
1106
1107 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1108                                                     rpmsg_rx_cb_t cb,
1109                                                     void *priv,
1110                                                     struct rpmsg_channel_info
1111                                                                         chinfo)
1112 {
1113         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1114         struct glink_channel *channel;
1115         struct qcom_glink *glink = parent->glink;
1116         struct rpmsg_endpoint *ept;
1117         const char *name = chinfo.name;
1118         int cid;
1119         int ret;
1120         unsigned long flags;
1121
1122         spin_lock_irqsave(&glink->idr_lock, flags);
1123         idr_for_each_entry(&glink->rcids, channel, cid) {
1124                 if (!strcmp(channel->name, name))
1125                         break;
1126         }
1127         spin_unlock_irqrestore(&glink->idr_lock, flags);
1128
1129         if (!channel) {
1130                 channel = qcom_glink_create_local(glink, name);
1131                 if (IS_ERR(channel))
1132                         return NULL;
1133         } else {
1134                 ret = qcom_glink_create_remote(glink, channel);
1135                 if (ret)
1136                         return NULL;
1137         }
1138
1139         ept = &channel->ept;
1140         ept->rpdev = rpdev;
1141         ept->cb = cb;
1142         ept->priv = priv;
1143         ept->ops = &glink_endpoint_ops;
1144
1145         return ept;
1146 }
1147
1148 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1149 {
1150         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1151         struct device_node *np = rpdev->dev.of_node;
1152         struct qcom_glink *glink = channel->glink;
1153         struct glink_core_rx_intent *intent;
1154         const struct property *prop = NULL;
1155         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1156         int num_intents;
1157         int num_groups = 1;
1158         __be32 *val = defaults;
1159         int size;
1160
1161         if (glink->intentless)
1162                 return 0;
1163
1164         prop = of_find_property(np, "qcom,intents", NULL);
1165         if (prop) {
1166                 val = prop->value;
1167                 num_groups = prop->length / sizeof(u32) / 2;
1168         }
1169
1170         /* Channel is now open, advertise base set of intents */
1171         while (num_groups--) {
1172                 size = be32_to_cpup(val++);
1173                 num_intents = be32_to_cpup(val++);
1174                 while (num_intents--) {
1175                         intent = qcom_glink_alloc_intent(glink, channel, size,
1176                                                          true);
1177                         if (!intent)
1178                                 break;
1179
1180                         qcom_glink_advertise_intent(glink, channel, intent);
1181                 }
1182         }
1183         return 0;
1184 }
1185
1186 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1187 {
1188         struct glink_channel *channel = to_glink_channel(ept);
1189         struct qcom_glink *glink = channel->glink;
1190         unsigned long flags;
1191
1192         spin_lock_irqsave(&channel->recv_lock, flags);
1193         channel->ept.cb = NULL;
1194         spin_unlock_irqrestore(&channel->recv_lock, flags);
1195
1196         /* Decouple the potential rpdev from the channel */
1197         channel->rpdev = NULL;
1198
1199         qcom_glink_send_close_req(glink, channel);
1200 }
1201
1202 static int qcom_glink_request_intent(struct qcom_glink *glink,
1203                                      struct glink_channel *channel,
1204                                      size_t size)
1205 {
1206         struct {
1207                 u16 id;
1208                 u16 cid;
1209                 u32 size;
1210         } __packed cmd;
1211
1212         int ret;
1213
1214         mutex_lock(&channel->intent_req_lock);
1215
1216         reinit_completion(&channel->intent_req_comp);
1217
1218         cmd.id = RPM_CMD_RX_INTENT_REQ;
1219         cmd.cid = channel->lcid;
1220         cmd.size = size;
1221
1222         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1223         if (ret)
1224                 goto unlock;
1225
1226         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1227         if (!ret) {
1228                 dev_err(glink->dev, "intent request timed out\n");
1229                 ret = -ETIMEDOUT;
1230         } else {
1231                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1232         }
1233
1234 unlock:
1235         mutex_unlock(&channel->intent_req_lock);
1236         return ret;
1237 }
1238
1239 static int __qcom_glink_send(struct glink_channel *channel,
1240                              void *data, int len, bool wait)
1241 {
1242         struct qcom_glink *glink = channel->glink;
1243         struct glink_core_rx_intent *intent = NULL;
1244         struct glink_core_rx_intent *tmp;
1245         int iid = 0;
1246         struct {
1247                 struct glink_msg msg;
1248                 __le32 chunk_size;
1249                 __le32 left_size;
1250         } __packed req;
1251         int ret;
1252         unsigned long flags;
1253
1254         if (!glink->intentless) {
1255                 while (!intent) {
1256                         spin_lock_irqsave(&channel->intent_lock, flags);
1257                         idr_for_each_entry(&channel->riids, tmp, iid) {
1258                                 if (tmp->size >= len && !tmp->in_use) {
1259                                         if (!intent)
1260                                                 intent = tmp;
1261                                         else if (intent->size > tmp->size)
1262                                                 intent = tmp;
1263                                         if (intent->size == len)
1264                                                 break;
1265                                 }
1266                         }
1267                         if (intent)
1268                                 intent->in_use = true;
1269                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1270
1271                         /* We found an available intent */
1272                         if (intent)
1273                                 break;
1274
1275                         if (!wait)
1276                                 return -EBUSY;
1277
1278                         ret = qcom_glink_request_intent(glink, channel, len);
1279                         if (ret < 0)
1280                                 return ret;
1281                 }
1282
1283                 iid = intent->id;
1284         }
1285
1286         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1287         req.msg.param1 = cpu_to_le16(channel->lcid);
1288         req.msg.param2 = cpu_to_le32(iid);
1289         req.chunk_size = cpu_to_le32(len);
1290         req.left_size = cpu_to_le32(0);
1291
1292         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1293
1294         /* Mark intent available if we failed */
1295         if (ret && intent)
1296                 intent->in_use = false;
1297
1298         return ret;
1299 }
1300
1301 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1302 {
1303         struct glink_channel *channel = to_glink_channel(ept);
1304
1305         return __qcom_glink_send(channel, data, len, true);
1306 }
1307
1308 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1309 {
1310         struct glink_channel *channel = to_glink_channel(ept);
1311
1312         return __qcom_glink_send(channel, data, len, false);
1313 }
1314
1315 /*
1316  * Finds the device_node for the glink child interested in this channel.
1317  */
1318 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1319                                                     const char *channel)
1320 {
1321         struct device_node *child;
1322         const char *name;
1323         const char *key;
1324         int ret;
1325
1326         for_each_available_child_of_node(node, child) {
1327                 key = "qcom,glink-channels";
1328                 ret = of_property_read_string(child, key, &name);
1329                 if (ret)
1330                         continue;
1331
1332                 if (strcmp(name, channel) == 0)
1333                         return child;
1334         }
1335
1336         return NULL;
1337 }
1338
1339 static const struct rpmsg_device_ops glink_device_ops = {
1340         .create_ept = qcom_glink_create_ept,
1341         .announce_create = qcom_glink_announce_create,
1342 };
1343
1344 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1345         .destroy_ept = qcom_glink_destroy_ept,
1346         .send = qcom_glink_send,
1347         .trysend = qcom_glink_trysend,
1348 };
1349
1350 static void qcom_glink_rpdev_release(struct device *dev)
1351 {
1352         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1353         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1354
1355         channel->rpdev = NULL;
1356         kfree(rpdev);
1357 }
1358
1359 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1360                               char *name)
1361 {
1362         struct glink_channel *channel;
1363         struct rpmsg_device *rpdev;
1364         bool create_device = false;
1365         struct device_node *node;
1366         int lcid;
1367         int ret;
1368         unsigned long flags;
1369
1370         spin_lock_irqsave(&glink->idr_lock, flags);
1371         idr_for_each_entry(&glink->lcids, channel, lcid) {
1372                 if (!strcmp(channel->name, name))
1373                         break;
1374         }
1375         spin_unlock_irqrestore(&glink->idr_lock, flags);
1376
1377         if (!channel) {
1378                 channel = qcom_glink_alloc_channel(glink, name);
1379                 if (IS_ERR(channel))
1380                         return PTR_ERR(channel);
1381
1382                 /* The opening dance was initiated by the remote */
1383                 create_device = true;
1384         }
1385
1386         spin_lock_irqsave(&glink->idr_lock, flags);
1387         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1388         if (ret < 0) {
1389                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1390                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1391                 goto free_channel;
1392         }
1393         channel->rcid = ret;
1394         spin_unlock_irqrestore(&glink->idr_lock, flags);
1395
1396         complete(&channel->open_req);
1397
1398         if (create_device) {
1399                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1400                 if (!rpdev) {
1401                         ret = -ENOMEM;
1402                         goto rcid_remove;
1403                 }
1404
1405                 rpdev->ept = &channel->ept;
1406                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1407                 rpdev->src = RPMSG_ADDR_ANY;
1408                 rpdev->dst = RPMSG_ADDR_ANY;
1409                 rpdev->ops = &glink_device_ops;
1410
1411                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1412                 rpdev->dev.of_node = node;
1413                 rpdev->dev.parent = glink->dev;
1414                 rpdev->dev.release = qcom_glink_rpdev_release;
1415
1416                 ret = rpmsg_register_device(rpdev);
1417                 if (ret)
1418                         goto free_rpdev;
1419
1420                 channel->rpdev = rpdev;
1421         }
1422
1423         return 0;
1424
1425 free_rpdev:
1426         kfree(rpdev);
1427 rcid_remove:
1428         spin_lock_irqsave(&glink->idr_lock, flags);
1429         idr_remove(&glink->rcids, channel->rcid);
1430         channel->rcid = 0;
1431         spin_unlock_irqrestore(&glink->idr_lock, flags);
1432 free_channel:
1433         /* Release the reference, iff we took it */
1434         if (create_device)
1435                 kref_put(&channel->refcount, qcom_glink_channel_release);
1436
1437         return ret;
1438 }
1439
1440 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1441 {
1442         struct rpmsg_channel_info chinfo;
1443         struct glink_channel *channel;
1444         unsigned long flags;
1445
1446         spin_lock_irqsave(&glink->idr_lock, flags);
1447         channel = idr_find(&glink->rcids, rcid);
1448         spin_unlock_irqrestore(&glink->idr_lock, flags);
1449         if (WARN(!channel, "close request on unknown channel\n"))
1450                 return;
1451
1452         /* cancel pending rx_done work */
1453         cancel_work_sync(&channel->intent_work);
1454
1455         if (channel->rpdev) {
1456                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1457                 chinfo.src = RPMSG_ADDR_ANY;
1458                 chinfo.dst = RPMSG_ADDR_ANY;
1459
1460                 rpmsg_unregister_device(glink->dev, &chinfo);
1461         }
1462
1463         qcom_glink_send_close_ack(glink, channel->rcid);
1464
1465         spin_lock_irqsave(&glink->idr_lock, flags);
1466         idr_remove(&glink->rcids, channel->rcid);
1467         channel->rcid = 0;
1468         spin_unlock_irqrestore(&glink->idr_lock, flags);
1469
1470         kref_put(&channel->refcount, qcom_glink_channel_release);
1471 }
1472
1473 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1474 {
1475         struct glink_channel *channel;
1476         unsigned long flags;
1477
1478         spin_lock_irqsave(&glink->idr_lock, flags);
1479         channel = idr_find(&glink->lcids, lcid);
1480         if (WARN(!channel, "close ack on unknown channel\n")) {
1481                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1482                 return;
1483         }
1484
1485         idr_remove(&glink->lcids, channel->lcid);
1486         channel->lcid = 0;
1487         spin_unlock_irqrestore(&glink->idr_lock, flags);
1488
1489         kref_put(&channel->refcount, qcom_glink_channel_release);
1490 }
1491
1492 static void qcom_glink_work(struct work_struct *work)
1493 {
1494         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1495                                                 rx_work);
1496         struct glink_defer_cmd *dcmd;
1497         struct glink_msg *msg;
1498         unsigned long flags;
1499         unsigned int param1;
1500         unsigned int param2;
1501         unsigned int cmd;
1502
1503         for (;;) {
1504                 spin_lock_irqsave(&glink->rx_lock, flags);
1505                 if (list_empty(&glink->rx_queue)) {
1506                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1507                         break;
1508                 }
1509                 dcmd = list_first_entry(&glink->rx_queue,
1510                                         struct glink_defer_cmd, node);
1511                 list_del(&dcmd->node);
1512                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1513
1514                 msg = &dcmd->msg;
1515                 cmd = le16_to_cpu(msg->cmd);
1516                 param1 = le16_to_cpu(msg->param1);
1517                 param2 = le32_to_cpu(msg->param2);
1518
1519                 switch (cmd) {
1520                 case RPM_CMD_VERSION:
1521                         qcom_glink_receive_version(glink, param1, param2);
1522                         break;
1523                 case RPM_CMD_VERSION_ACK:
1524                         qcom_glink_receive_version_ack(glink, param1, param2);
1525                         break;
1526                 case RPM_CMD_OPEN:
1527                         qcom_glink_rx_open(glink, param1, msg->data);
1528                         break;
1529                 case RPM_CMD_CLOSE:
1530                         qcom_glink_rx_close(glink, param1);
1531                         break;
1532                 case RPM_CMD_CLOSE_ACK:
1533                         qcom_glink_rx_close_ack(glink, param1);
1534                         break;
1535                 case RPM_CMD_RX_INTENT_REQ:
1536                         qcom_glink_handle_intent_req(glink, param1, param2);
1537                         break;
1538                 default:
1539                         WARN(1, "Unknown defer object %d\n", cmd);
1540                         break;
1541                 }
1542
1543                 kfree(dcmd);
1544         }
1545 }
1546
1547 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1548                                            unsigned long features,
1549                                            struct qcom_glink_pipe *rx,
1550                                            struct qcom_glink_pipe *tx,
1551                                            bool intentless)
1552 {
1553         int irq;
1554         int ret;
1555         struct qcom_glink *glink;
1556
1557         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1558         if (!glink)
1559                 return ERR_PTR(-ENOMEM);
1560
1561         glink->dev = dev;
1562         glink->tx_pipe = tx;
1563         glink->rx_pipe = rx;
1564
1565         glink->features = features;
1566         glink->intentless = intentless;
1567
1568         spin_lock_init(&glink->tx_lock);
1569         spin_lock_init(&glink->rx_lock);
1570         INIT_LIST_HEAD(&glink->rx_queue);
1571         INIT_WORK(&glink->rx_work, qcom_glink_work);
1572
1573         spin_lock_init(&glink->idr_lock);
1574         idr_init(&glink->lcids);
1575         idr_init(&glink->rcids);
1576
1577         ret = of_property_read_string(dev->of_node, "label", &glink->name);
1578         if (ret < 0)
1579                 glink->name = dev->of_node->name;
1580
1581         glink->mbox_client.dev = dev;
1582         glink->mbox_client.knows_txdone = true;
1583         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1584         if (IS_ERR(glink->mbox_chan)) {
1585                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1586                         dev_err(dev, "failed to acquire IPC channel\n");
1587                 return ERR_CAST(glink->mbox_chan);
1588         }
1589
1590         irq = of_irq_get(dev->of_node, 0);
1591         ret = devm_request_irq(dev, irq,
1592                                qcom_glink_native_intr,
1593                                IRQF_NO_SUSPEND | IRQF_SHARED,
1594                                "glink-native", glink);
1595         if (ret) {
1596                 dev_err(dev, "failed to request IRQ\n");
1597                 return ERR_PTR(ret);
1598         }
1599
1600         glink->irq = irq;
1601
1602         ret = qcom_glink_send_version(glink);
1603         if (ret)
1604                 return ERR_PTR(ret);
1605
1606         return glink;
1607 }
1608 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1609
1610 static int qcom_glink_remove_device(struct device *dev, void *data)
1611 {
1612         device_unregister(dev);
1613
1614         return 0;
1615 }
1616
1617 void qcom_glink_native_remove(struct qcom_glink *glink)
1618 {
1619         struct glink_channel *channel;
1620         int cid;
1621         int ret;
1622         unsigned long flags;
1623
1624         disable_irq(glink->irq);
1625         cancel_work_sync(&glink->rx_work);
1626
1627         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1628         if (ret)
1629                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1630
1631         spin_lock_irqsave(&glink->idr_lock, flags);
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         idr_destroy(&glink->lcids);
1637         idr_destroy(&glink->rcids);
1638         spin_unlock_irqrestore(&glink->idr_lock, flags);
1639         mbox_free_channel(glink->mbox_chan);
1640 }
1641 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1642
1643 void qcom_glink_native_unregister(struct qcom_glink *glink)
1644 {
1645         device_unregister(glink->dev);
1646 }
1647 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1648
1649 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1650 MODULE_LICENSE("GPL v2");