drivers/rpmsg/qcom_glink_native.c

   1 /*
   2  * Copyright (c) 2016-2017, Linaro Ltd
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/idr.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/list.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_irq.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regmap.h>
  25 #include <linux/rpmsg.h>
  26 #include <linux/sizes.h>
  27 #include <linux/slab.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/mailbox_client.h>
  30
  31 #include "rpmsg_internal.h"
  32 #include "qcom_glink_native.h"
  33
  34 #define GLINK_NAME_SIZE         32
  35 #define GLINK_VERSION_1         1
  36
  37 #define RPM_GLINK_CID_MIN       1
  38 #define RPM_GLINK_CID_MAX       65536
  39
  40 struct glink_msg {
  41         __le16 cmd;
  42         __le16 param1;
  43         __le32 param2;
  44         u8 data[];
  45 } __packed;
  46
  47 /**
  48  * struct glink_defer_cmd - deferred incoming control message
  49  * @node:       list node
  50  * @msg:        message header
  51  * data:        payload of the message
  52  *
  53  * Copy of a received control message, to be added to @rx_queue and processed
  54  * by @rx_work of @qcom_glink.
  55  */
  56 struct glink_defer_cmd {
  57         struct list_head node;
  58
  59         struct glink_msg msg;
  60         u8 data[];
  61 };
  62
  63 /**
  64  * struct glink_core_rx_intent - RX intent
  65  * RX intent
  66  *
  67  * data: pointer to the data (may be NULL for zero-copy)
  68  * id: remote or local intent ID
  69  * size: size of the original intent (do not modify)
  70  * reuse: To mark if the intent can be reused after first use
  71  * in_use: To mark if intent is already in use for the channel
  72  * offset: next write offset (initially 0)
  73  */
  74 struct glink_core_rx_intent {
  75         void *data;
  76         u32 id;
  77         size_t size;
  78         bool reuse;
  79         bool in_use;
  80         u32 offset;
  81
  82         struct list_head node;
  83 };
  84
  85 /**
  86  * struct qcom_glink - driver context, relates to one remote subsystem
  87  * @dev:        reference to the associated struct device
  88  * @mbox_client: mailbox client
  89  * @mbox_chan:  mailbox channel
  90  * @rx_pipe:    pipe object for receive FIFO
  91  * @tx_pipe:    pipe object for transmit FIFO
  92  * @irq:        IRQ for signaling incoming events
  93  * @rx_work:    worker for handling received control messages
  94  * @rx_lock:    protects the @rx_queue
  95  * @rx_queue:   queue of received control messages to be processed in @rx_work
  96  * @tx_lock:    synchronizes operations on the tx fifo
  97  * @idr_lock:   synchronizes @lcids and @rcids modifications
  98  * @lcids:      idr of all channels with a known local channel id
  99  * @rcids:      idr of all channels with a known remote channel id
 100  */
 101 struct qcom_glink {
 102         struct device *dev;
 103
 104         struct mbox_client mbox_client;
 105         struct mbox_chan *mbox_chan;
 106
 107         struct qcom_glink_pipe *rx_pipe;
 108         struct qcom_glink_pipe *tx_pipe;
 109
 110         int irq;
 111
 112         struct work_struct rx_work;
 113         spinlock_t rx_lock;
 114         struct list_head rx_queue;
 115
 116         struct mutex tx_lock;
 117
 118         spinlock_t idr_lock;
 119         struct idr lcids;
 120         struct idr rcids;
 121         unsigned long features;
 122
 123         bool intentless;
 124 };
 125
 126 enum {
 127         GLINK_STATE_CLOSED,
 128         GLINK_STATE_OPENING,
 129         GLINK_STATE_OPEN,
 130         GLINK_STATE_CLOSING,
 131 };
 132
 133 /**
 134  * struct glink_channel - internal representation of a channel
 135  * @rpdev:      rpdev reference, only used for primary endpoints
 136  * @ept:        rpmsg endpoint this channel is associated with
 137  * @glink:      qcom_glink context handle
 138  * @refcount:   refcount for the channel object
 139  * @recv_lock:  guard for @ept.cb
 140  * @name:       unique channel name/identifier
 141  * @lcid:       channel id, in local space
 142  * @rcid:       channel id, in remote space
 143  * @intent_lock: lock for protection of @liids, @riids
 144  * @liids:      idr of all local intents
 145  * @riids:      idr of all remote intents
 146  * @intent_work: worker responsible for transmitting rx_done packets
 147  * @done_intents: list of intents that needs to be announced rx_done
 148  * @buf:        receive buffer, for gathering fragments
 149  * @buf_offset: write offset in @buf
 150  * @buf_size:   size of current @buf
 151  * @open_ack:   completed once remote has acked the open-request
 152  * @open_req:   completed once open-request has been received
 153  * @intent_req_lock: Synchronises multiple intent requests
 154  * @intent_req_result: Result of intent request
 155  * @intent_req_comp: Completion for intent_req signalling
 156  */
 157 struct glink_channel {
 158         struct rpmsg_endpoint ept;
 159
 160         struct rpmsg_device *rpdev;
 161         struct qcom_glink *glink;
 162
 163         struct kref refcount;
 164
 165         spinlock_t recv_lock;
 166
 167         char *name;
 168         unsigned int lcid;
 169         unsigned int rcid;
 170
 171         spinlock_t intent_lock;
 172         struct idr liids;
 173         struct idr riids;
 174         struct work_struct intent_work;
 175         struct list_head done_intents;
 176
 177         struct glink_core_rx_intent *buf;
 178         int buf_offset;
 179         int buf_size;
 180
 181         struct completion open_ack;
 182         struct completion open_req;
 183
 184         struct mutex intent_req_lock;
 185         bool intent_req_result;
 186         struct completion intent_req_comp;
 187 };
 188
 189 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 190
 191 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 192
 193 #define RPM_CMD_VERSION                 0
 194 #define RPM_CMD_VERSION_ACK             1
 195 #define RPM_CMD_OPEN                    2
 196 #define RPM_CMD_CLOSE                   3
 197 #define RPM_CMD_OPEN_ACK                4
 198 #define RPM_CMD_INTENT                  5
 199 #define RPM_CMD_RX_DONE                 6
 200 #define RPM_CMD_RX_INTENT_REQ           7
 201 #define RPM_CMD_RX_INTENT_REQ_ACK       8
 202 #define RPM_CMD_TX_DATA                 9
 203 #define RPM_CMD_CLOSE_ACK               11
 204 #define RPM_CMD_TX_DATA_CONT            12
 205 #define RPM_CMD_READ_NOTIF              13
 206 #define RPM_CMD_RX_DONE_W_REUSE         14
 207
 208 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 209
 210 static void qcom_glink_rx_done_work(struct work_struct *work);
 211
 212 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 213                                                       const char *name)
 214 {
 215         struct glink_channel *channel;
 216
 217         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 218         if (!channel)
 219                 return ERR_PTR(-ENOMEM);
 220
 221         /* Setup glink internal glink_channel data */
 222         spin_lock_init(&channel->recv_lock);
 223         spin_lock_init(&channel->intent_lock);
 224         mutex_init(&channel->intent_req_lock);
 225
 226         channel->glink = glink;
 227         channel->name = kstrdup(name, GFP_KERNEL);
 228
 229         init_completion(&channel->open_req);
 230         init_completion(&channel->open_ack);
 231         init_completion(&channel->intent_req_comp);
 232
 233         INIT_LIST_HEAD(&channel->done_intents);
 234         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 235
 236         idr_init(&channel->liids);
 237         idr_init(&channel->riids);
 238         kref_init(&channel->refcount);
 239
 240         return channel;
 241 }
 242
 243 static void qcom_glink_channel_release(struct kref *ref)
 244 {
 245         struct glink_channel *channel = container_of(ref, struct glink_channel,
 246                                                      refcount);
 247         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         int ret;
 292
 293         /* Reject packets that are too big */
 294         if (tlen >= glink->tx_pipe->length)
 295                 return -EINVAL;
 296
 297         ret = mutex_lock_interruptible(&glink->tx_lock);
 298         if (ret)
 299                 return ret;
 300
 301         while (qcom_glink_tx_avail(glink) < tlen) {
 302                 if (!wait) {
 303                         ret = -EAGAIN;
 304                         goto out;
 305                 }
 306
 307                 usleep_range(10000, 15000);
 308         }
 309
 310         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 311
 312         mbox_send_message(glink->mbox_chan, NULL);
 313         mbox_client_txdone(glink->mbox_chan, 0);
 314
 315 out:
 316         mutex_unlock(&glink->tx_lock);
 317
 318         return ret;
 319 }
 320
 321 static int qcom_glink_send_version(struct qcom_glink *glink)
 322 {
 323         struct glink_msg msg;
 324
 325         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 326         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 327         msg.param2 = cpu_to_le32(glink->features);
 328
 329         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 330 }
 331
 332 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 333 {
 334         struct glink_msg msg;
 335
 336         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 337         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 338         msg.param2 = cpu_to_le32(glink->features);
 339
 340         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 341 }
 342
 343 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 344                                      struct glink_channel *channel)
 345 {
 346         struct glink_msg msg;
 347
 348         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 349         msg.param1 = cpu_to_le16(channel->rcid);
 350         msg.param2 = cpu_to_le32(0);
 351
 352         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 353 }
 354
 355 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 356                                              unsigned int cid, bool granted)
 357 {
 358         struct glink_channel *channel;
 359         unsigned long flags;
 360
 361         spin_lock_irqsave(&glink->idr_lock, flags);
 362         channel = idr_find(&glink->rcids, cid);
 363         spin_unlock_irqrestore(&glink->idr_lock, flags);
 364         if (!channel) {
 365                 dev_err(glink->dev, "unable to find channel\n");
 366                 return;
 367         }
 368
 369         channel->intent_req_result = granted;
 370         complete(&channel->intent_req_comp);
 371 }
 372
 373 /**
 374  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 375  * @glink: Ptr to the glink edge
 376  * @channel: Ptr to the channel that the open req is sent
 377  *
 378  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 379  * Will return with refcount held, regardless of outcome.
 380  *
 381  * Returns 0 on success, negative errno otherwise.
 382  */
 383 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 384                                     struct glink_channel *channel)
 385 {
 386         struct {
 387                 struct glink_msg msg;
 388                 u8 name[GLINK_NAME_SIZE];
 389         } __packed req;
 390         int name_len = strlen(channel->name) + 1;
 391         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 392         int ret;
 393         unsigned long flags;
 394
 395         kref_get(&channel->refcount);
 396
 397         spin_lock_irqsave(&glink->idr_lock, flags);
 398         ret = idr_alloc_cyclic(&glink->lcids, channel,
 399                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 400                                GFP_ATOMIC);
 401         spin_unlock_irqrestore(&glink->idr_lock, flags);
 402         if (ret < 0)
 403                 return ret;
 404
 405         channel->lcid = ret;
 406
 407         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 408         req.msg.param1 = cpu_to_le16(channel->lcid);
 409         req.msg.param2 = cpu_to_le32(name_len);
 410         strcpy(req.name, channel->name);
 411
 412         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 413         if (ret)
 414                 goto remove_idr;
 415
 416         return 0;
 417
 418 remove_idr:
 419         spin_lock_irqsave(&glink->idr_lock, flags);
 420         idr_remove(&glink->lcids, channel->lcid);
 421         channel->lcid = 0;
 422         spin_unlock_irqrestore(&glink->idr_lock, flags);
 423
 424         return ret;
 425 }
 426
 427 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 428                                       struct glink_channel *channel)
 429 {
 430         struct glink_msg req;
 431
 432         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 433         req.param1 = cpu_to_le16(channel->lcid);
 434         req.param2 = 0;
 435
 436         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 437 }
 438
 439 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 440                                       unsigned int rcid)
 441 {
 442         struct glink_msg req;
 443
 444         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 445         req.param1 = cpu_to_le16(rcid);
 446         req.param2 = 0;
 447
 448         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 449 }
 450
 451 static void qcom_glink_rx_done_work(struct work_struct *work)
 452 {
 453         struct glink_channel *channel = container_of(work, struct glink_channel,
 454                                                      intent_work);
 455         struct qcom_glink *glink = channel->glink;
 456         struct glink_core_rx_intent *intent, *tmp;
 457         struct {
 458                 u16 id;
 459                 u16 lcid;
 460                 u32 liid;
 461         } __packed cmd;
 462
 463         unsigned int cid = channel->lcid;
 464         unsigned int iid;
 465         bool reuse;
 466         unsigned long flags;
 467
 468         spin_lock_irqsave(&channel->intent_lock, flags);
 469         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 470                 list_del(&intent->node);
 471                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 472                 iid = intent->id;
 473                 reuse = intent->reuse;
 474
 475                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 476                 cmd.lcid = cid;
 477                 cmd.liid = iid;
 478
 479                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 480                 if (!reuse) {
 481                         kfree(intent->data);
 482                         kfree(intent);
 483                 }
 484                 spin_lock_irqsave(&channel->intent_lock, flags);
 485         }
 486         spin_unlock_irqrestore(&channel->intent_lock, flags);
 487 }
 488
 489 static void qcom_glink_rx_done(struct qcom_glink *glink,
 490                                struct glink_channel *channel,
 491                                struct glink_core_rx_intent *intent)
 492 {
 493         /* We don't send RX_DONE to intentless systems */
 494         if (glink->intentless) {
 495                 kfree(intent->data);
 496                 kfree(intent);
 497                 return;
 498         }
 499
 500         /* Take it off the tree of receive intents */
 501         if (!intent->reuse) {
 502                 spin_lock(&channel->intent_lock);
 503                 idr_remove(&channel->liids, intent->id);
 504                 spin_unlock(&channel->intent_lock);
 505         }
 506
 507         /* Schedule the sending of a rx_done indication */
 508         spin_lock(&channel->intent_lock);
 509         list_add_tail(&intent->node, &channel->done_intents);
 510         spin_unlock(&channel->intent_lock);
 511
 512         schedule_work(&channel->intent_work);
 513 }
 514
 515 /**
 516  * qcom_glink_receive_version() - receive version/features from remote system
 517  *
 518  * @glink:      pointer to transport interface
 519  * @r_version:  remote version
 520  * @r_features: remote features
 521  *
 522  * This function is called in response to a remote-initiated version/feature
 523  * negotiation sequence.
 524  */
 525 static void qcom_glink_receive_version(struct qcom_glink *glink,
 526                                        u32 version,
 527                                        u32 features)
 528 {
 529         switch (version) {
 530         case 0:
 531                 break;
 532         case GLINK_VERSION_1:
 533                 glink->features &= features;
 534                 /* FALLTHROUGH */
 535         default:
 536                 qcom_glink_send_version_ack(glink);
 537                 break;
 538         }
 539 }
 540
 541 /**
 542  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 543  *
 544  * @glink:      pointer to transport interface
 545  * @r_version:  remote version response
 546  * @r_features: remote features response
 547  *
 548  * This function is called in response to a local-initiated version/feature
 549  * negotiation sequence and is the counter-offer from the remote side based
 550  * upon the initial version and feature set requested.
 551  */
 552 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 553                                            u32 version,
 554                                            u32 features)
 555 {
 556         switch (version) {
 557         case 0:
 558                 /* Version negotiation failed */
 559                 break;
 560         case GLINK_VERSION_1:
 561                 if (features == glink->features)
 562                         break;
 563
 564                 glink->features &= features;
 565                 /* FALLTHROUGH */
 566         default:
 567                 qcom_glink_send_version(glink);
 568                 break;
 569         }
 570 }
 571
 572 /**
 573  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 574                                       wire format and transmit
 575  * @glink:      The transport to transmit on.
 576  * @channel:    The glink channel
 577  * @granted:    The request response to encode.
 578  *
 579  * Return: 0 on success or standard Linux error code.
 580  */
 581 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 582                                           struct glink_channel *channel,
 583                                           bool granted)
 584 {
 585         struct glink_msg msg;
 586
 587         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 588         msg.param1 = cpu_to_le16(channel->lcid);
 589         msg.param2 = cpu_to_le32(granted);
 590
 591         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 592
 593         return 0;
 594 }
 595
 596 /**
 597  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 598  *                         transmit
 599  * @glink:      The transport to transmit on.
 600  * @channel:    The local channel
 601  * @size:       The intent to pass on to remote.
 602  *
 603  * Return: 0 on success or standard Linux error code.
 604  */
 605 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 606                                        struct glink_channel *channel,
 607                                        struct glink_core_rx_intent *intent)
 608 {
 609         struct command {
 610                 u16 id;
 611                 u16 lcid;
 612                 u32 count;
 613                 u32 size;
 614                 u32 liid;
 615         } __packed;
 616         struct command cmd;
 617
 618         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 619         cmd.lcid = cpu_to_le16(channel->lcid);
 620         cmd.count = cpu_to_le32(1);
 621         cmd.size = cpu_to_le32(intent->size);
 622         cmd.liid = cpu_to_le32(intent->id);
 623
 624         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 625
 626         return 0;
 627 }
 628
 629 static struct glink_core_rx_intent *
 630 qcom_glink_alloc_intent(struct qcom_glink *glink,
 631                         struct glink_channel *channel,
 632                         size_t size,
 633                         bool reuseable)
 634 {
 635         struct glink_core_rx_intent *intent;
 636         int ret;
 637         unsigned long flags;
 638
 639         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 640         if (!intent)
 641                 return NULL;
 642
 643         intent->data = kzalloc(size, GFP_KERNEL);
 644         if (!intent->data)
 645                 goto free_intent;
 646
 647         spin_lock_irqsave(&channel->intent_lock, flags);
 648         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 649         if (ret < 0) {
 650                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 651                 goto free_data;
 652         }
 653         spin_unlock_irqrestore(&channel->intent_lock, flags);
 654
 655         intent->id = ret;
 656         intent->size = size;
 657         intent->reuse = reuseable;
 658
 659         return intent;
 660
 661 free_data:
 662         kfree(intent->data);
 663 free_intent:
 664         kfree(intent);
 665         return NULL;
 666 }
 667
 668 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 669                                       u32 cid, uint32_t iid,
 670                                       bool reuse)
 671 {
 672         struct glink_core_rx_intent *intent;
 673         struct glink_channel *channel;
 674         unsigned long flags;
 675
 676         spin_lock_irqsave(&glink->idr_lock, flags);
 677         channel = idr_find(&glink->rcids, cid);
 678         spin_unlock_irqrestore(&glink->idr_lock, flags);
 679         if (!channel) {
 680                 dev_err(glink->dev, "invalid channel id received\n");
 681                 return;
 682         }
 683
 684         spin_lock_irqsave(&channel->intent_lock, flags);
 685         intent = idr_find(&channel->riids, iid);
 686
 687         if (!intent) {
 688                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 689                 dev_err(glink->dev, "invalid intent id received\n");
 690                 return;
 691         }
 692
 693         intent->in_use = false;
 694
 695         if (!reuse) {
 696                 idr_remove(&channel->riids, intent->id);
 697                 kfree(intent);
 698         }
 699         spin_unlock_irqrestore(&channel->intent_lock, flags);
 700 }
 701
 702 /**
 703  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 704  *                                          from remote side
 705  * if_ptr:      Pointer to the transport interface
 706  * rcid:        Remote channel ID
 707  * size:        size of the intent
 708  *
 709  * The function searches for the local channel to which the request for
 710  * rx_intent has arrived and allocates and notifies the remote back
 711  */
 712 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 713                                          u32 cid, size_t size)
 714 {
 715         struct glink_core_rx_intent *intent;
 716         struct glink_channel *channel;
 717         unsigned long flags;
 718
 719         spin_lock_irqsave(&glink->idr_lock, flags);
 720         channel = idr_find(&glink->rcids, cid);
 721         spin_unlock_irqrestore(&glink->idr_lock, flags);
 722
 723         if (!channel) {
 724                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 725                 return;
 726         }
 727
 728         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 729         if (intent)
 730                 qcom_glink_advertise_intent(glink, channel, intent);
 731
 732         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 733 }
 734
 735 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 736 {
 737         struct glink_defer_cmd *dcmd;
 738
 739         extra = ALIGN(extra, 8);
 740
 741         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 742                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 743                 return -ENXIO;
 744         }
 745
 746         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 747         if (!dcmd)
 748                 return -ENOMEM;
 749
 750         INIT_LIST_HEAD(&dcmd->node);
 751
 752         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 753
 754         spin_lock(&glink->rx_lock);
 755         list_add_tail(&dcmd->node, &glink->rx_queue);
 756         spin_unlock(&glink->rx_lock);
 757
 758         schedule_work(&glink->rx_work);
 759         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 760
 761         return 0;
 762 }
 763
 764 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 765 {
 766         struct glink_core_rx_intent *intent;
 767         struct glink_channel *channel;
 768         struct {
 769                 struct glink_msg msg;
 770                 __le32 chunk_size;
 771                 __le32 left_size;
 772         } __packed hdr;
 773         unsigned int chunk_size;
 774         unsigned int left_size;
 775         unsigned int rcid;
 776         unsigned int liid;
 777         int ret = 0;
 778         unsigned long flags;
 779
 780         if (avail < sizeof(hdr)) {
 781                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 782                 return -EAGAIN;
 783         }
 784
 785         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 786         chunk_size = le32_to_cpu(hdr.chunk_size);
 787         left_size = le32_to_cpu(hdr.left_size);
 788
 789         if (avail < sizeof(hdr) + chunk_size) {
 790                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 791                 return -EAGAIN;
 792         }
 793
 794         if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
 795                 return -EINVAL;
 796
 797         rcid = le16_to_cpu(hdr.msg.param1);
 798         spin_lock_irqsave(&glink->idr_lock, flags);
 799         channel = idr_find(&glink->rcids, rcid);
 800         spin_unlock_irqrestore(&glink->idr_lock, flags);
 801         if (!channel) {
 802                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 803
 804                 /* Drop the message */
 805                 goto advance_rx;
 806         }
 807
 808         if (glink->intentless) {
 809                 /* Might have an ongoing, fragmented, message to append */
 810                 if (!channel->buf) {
 811                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 812                         if (!intent)
 813                                 return -ENOMEM;
 814
 815                         intent->data = kmalloc(chunk_size + left_size,
 816                                                GFP_ATOMIC);
 817                         if (!intent->data) {
 818                                 kfree(intent);
 819                                 return -ENOMEM;
 820                         }
 821
 822                         intent->id = 0xbabababa;
 823                         intent->size = chunk_size + left_size;
 824                         intent->offset = 0;
 825
 826                         channel->buf = intent;
 827                 } else {
 828                         intent = channel->buf;
 829                 }
 830         } else {
 831                 liid = le32_to_cpu(hdr.msg.param2);
 832
 833                 spin_lock_irqsave(&channel->intent_lock, flags);
 834                 intent = idr_find(&channel->liids, liid);
 835                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 836
 837                 if (!intent) {
 838                         dev_err(glink->dev,
 839                                 "no intent found for channel %s intent %d",
 840                                 channel->name, liid);
 841                         goto advance_rx;
 842                 }
 843         }
 844
 845         if (intent->size - intent->offset < chunk_size) {
 846                 dev_err(glink->dev, "Insufficient space in intent\n");
 847
 848                 /* The packet header lied, drop payload */
 849                 goto advance_rx;
 850         }
 851
 852         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 853                            sizeof(hdr), chunk_size);
 854         intent->offset += chunk_size;
 855
 856         /* Handle message when no fragments remain to be received */
 857         if (!left_size) {
 858                 spin_lock(&channel->recv_lock);
 859                 if (channel->ept.cb) {
 860                         channel->ept.cb(channel->ept.rpdev,
 861                                         intent->data,
 862                                         intent->offset,
 863                                         channel->ept.priv,
 864                                         RPMSG_ADDR_ANY);
 865                 }
 866                 spin_unlock(&channel->recv_lock);
 867
 868                 intent->offset = 0;
 869                 channel->buf = NULL;
 870
 871                 qcom_glink_rx_done(glink, channel, intent);
 872         }
 873
 874 advance_rx:
 875         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 876
 877         return ret;
 878 }
 879
 880 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 881                                      unsigned int cid,
 882                                      unsigned int count,
 883                                      size_t avail)
 884 {
 885         struct glink_core_rx_intent *intent;
 886         struct glink_channel *channel;
 887         struct intent_pair {
 888                 __le32 size;
 889                 __le32 iid;
 890         };
 891
 892         struct {
 893                 struct glink_msg msg;
 894                 struct intent_pair intents[];
 895         } __packed * msg;
 896
 897         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
 898         int ret;
 899         int i;
 900         unsigned long flags;
 901
 902         if (avail < msglen) {
 903                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 904                 return;
 905         }
 906
 907         spin_lock_irqsave(&glink->idr_lock, flags);
 908         channel = idr_find(&glink->rcids, cid);
 909         spin_unlock_irqrestore(&glink->idr_lock, flags);
 910         if (!channel) {
 911                 dev_err(glink->dev, "intents for non-existing channel\n");
 912                 return;
 913         }
 914
 915         msg = kmalloc(msglen, GFP_ATOMIC);
 916         if (!msg)
 917                 return;
 918
 919         qcom_glink_rx_peak(glink, msg, 0, msglen);
 920
 921         for (i = 0; i < count; ++i) {
 922                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 923                 if (!intent)
 924                         break;
 925
 926                 intent->id = le32_to_cpu(msg->intents[i].iid);
 927                 intent->size = le32_to_cpu(msg->intents[i].size);
 928
 929                 spin_lock_irqsave(&channel->intent_lock, flags);
 930                 ret = idr_alloc(&channel->riids, intent,
 931                                 intent->id, intent->id + 1, GFP_ATOMIC);
 932                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 933
 934                 if (ret < 0)
 935                         dev_err(glink->dev, "failed to store remote intent\n");
 936         }
 937
 938         kfree(msg);
 939         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 940 }
 941
 942 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 943 {
 944         struct glink_channel *channel;
 945
 946         spin_lock(&glink->idr_lock);
 947         channel = idr_find(&glink->lcids, lcid);
 948         spin_unlock(&glink->idr_lock);
 949         if (!channel) {
 950                 dev_err(glink->dev, "Invalid open ack packet\n");
 951                 return -EINVAL;
 952         }
 953
 954         complete(&channel->open_ack);
 955
 956         return 0;
 957 }
 958
 959 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 960 {
 961         struct qcom_glink *glink = data;
 962         struct glink_msg msg;
 963         unsigned int param1;
 964         unsigned int param2;
 965         unsigned int avail;
 966         unsigned int cmd;
 967         int ret = 0;
 968
 969         for (;;) {
 970                 avail = qcom_glink_rx_avail(glink);
 971                 if (avail < sizeof(msg))
 972                         break;
 973
 974                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 975
 976                 cmd = le16_to_cpu(msg.cmd);
 977                 param1 = le16_to_cpu(msg.param1);
 978                 param2 = le32_to_cpu(msg.param2);
 979
 980                 switch (cmd) {
 981                 case RPM_CMD_VERSION:
 982                 case RPM_CMD_VERSION_ACK:
 983                 case RPM_CMD_CLOSE:
 984                 case RPM_CMD_CLOSE_ACK:
 985                 case RPM_CMD_RX_INTENT_REQ:
 986                         ret = qcom_glink_rx_defer(glink, 0);
 987                         break;
 988                 case RPM_CMD_OPEN_ACK:
 989                         ret = qcom_glink_rx_open_ack(glink, param1);
 990                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
 991                         break;
 992                 case RPM_CMD_OPEN:
 993                         ret = qcom_glink_rx_defer(glink, param2);
 994                         break;
 995                 case RPM_CMD_TX_DATA:
 996                 case RPM_CMD_TX_DATA_CONT:
 997                         ret = qcom_glink_rx_data(glink, avail);
 998                         break;
 999                 case RPM_CMD_READ_NOTIF:
1000                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1001
1002                         mbox_send_message(glink->mbox_chan, NULL);
1003                         mbox_client_txdone(glink->mbox_chan, 0);
1004                         break;
1005                 case RPM_CMD_INTENT:
1006                         qcom_glink_handle_intent(glink, param1, param2, avail);
1007                         break;
1008                 case RPM_CMD_RX_DONE:
1009                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1010                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1011                         break;
1012                 case RPM_CMD_RX_DONE_W_REUSE:
1013                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1014                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1015                         break;
1016                 case RPM_CMD_RX_INTENT_REQ_ACK:
1017                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1018                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1019                         break;
1020                 default:
1021                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1022                         ret = -EINVAL;
1023                         break;
1024                 }
1025
1026                 if (ret)
1027                         break;
1028         }
1029
1030         return IRQ_HANDLED;
1031 }
1032
1033 /* Locally initiated rpmsg_create_ept */
1034 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1035                                                      const char *name)
1036 {
1037         struct glink_channel *channel;
1038         int ret;
1039         unsigned long flags;
1040
1041         channel = qcom_glink_alloc_channel(glink, name);
1042         if (IS_ERR(channel))
1043                 return ERR_CAST(channel);
1044
1045         ret = qcom_glink_send_open_req(glink, channel);
1046         if (ret)
1047                 goto release_channel;
1048
1049         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1050         if (!ret)
1051                 goto err_timeout;
1052
1053         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1054         if (!ret)
1055                 goto err_timeout;
1056
1057         qcom_glink_send_open_ack(glink, channel);
1058
1059         return channel;
1060
1061 err_timeout:
1062         /* qcom_glink_send_open_req() did register the channel in lcids*/
1063         spin_lock_irqsave(&glink->idr_lock, flags);
1064         idr_remove(&glink->lcids, channel->lcid);
1065         spin_unlock_irqrestore(&glink->idr_lock, flags);
1066
1067 release_channel:
1068         /* Release qcom_glink_send_open_req() reference */
1069         kref_put(&channel->refcount, qcom_glink_channel_release);
1070         /* Release qcom_glink_alloc_channel() reference */
1071         kref_put(&channel->refcount, qcom_glink_channel_release);
1072
1073         return ERR_PTR(-ETIMEDOUT);
1074 }
1075
1076 /* Remote initiated rpmsg_create_ept */
1077 static int qcom_glink_create_remote(struct qcom_glink *glink,
1078                                     struct glink_channel *channel)
1079 {
1080         int ret;
1081
1082         qcom_glink_send_open_ack(glink, channel);
1083
1084         ret = qcom_glink_send_open_req(glink, channel);
1085         if (ret)
1086                 goto close_link;
1087
1088         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1089         if (!ret) {
1090                 ret = -ETIMEDOUT;
1091                 goto close_link;
1092         }
1093
1094         return 0;
1095
1096 close_link:
1097         /*
1098          * Send a close request to "undo" our open-ack. The close-ack will
1099          * release the last reference.
1100          */
1101         qcom_glink_send_close_req(glink, channel);
1102
1103         /* Release qcom_glink_send_open_req() reference */
1104         kref_put(&channel->refcount, qcom_glink_channel_release);
1105
1106         return ret;
1107 }
1108
1109 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1110                                                     rpmsg_rx_cb_t cb,
1111                                                     void *priv,
1112                                                     struct rpmsg_channel_info
1113                                                                         chinfo)
1114 {
1115         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1116         struct glink_channel *channel;
1117         struct qcom_glink *glink = parent->glink;
1118         struct rpmsg_endpoint *ept;
1119         const char *name = chinfo.name;
1120         int cid;
1121         int ret;
1122         unsigned long flags;
1123
1124         spin_lock_irqsave(&glink->idr_lock, flags);
1125         idr_for_each_entry(&glink->rcids, channel, cid) {
1126                 if (!strcmp(channel->name, name))
1127                         break;
1128         }
1129         spin_unlock_irqrestore(&glink->idr_lock, flags);
1130
1131         if (!channel) {
1132                 channel = qcom_glink_create_local(glink, name);
1133                 if (IS_ERR(channel))
1134                         return NULL;
1135         } else {
1136                 ret = qcom_glink_create_remote(glink, channel);
1137                 if (ret)
1138                         return NULL;
1139         }
1140
1141         ept = &channel->ept;
1142         ept->rpdev = rpdev;
1143         ept->cb = cb;
1144         ept->priv = priv;
1145         ept->ops = &glink_endpoint_ops;
1146
1147         return ept;
1148 }
1149
1150 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1151 {
1152         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1153         struct device_node *np = rpdev->dev.of_node;
1154         struct qcom_glink *glink = channel->glink;
1155         struct glink_core_rx_intent *intent;
1156         const struct property *prop = NULL;
1157         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1158         int num_intents;
1159         int num_groups = 1;
1160         __be32 *val = defaults;
1161         int size;
1162
1163         if (glink->intentless)
1164                 return 0;
1165
1166         prop = of_find_property(np, "qcom,intents", NULL);
1167         if (prop) {
1168                 val = prop->value;
1169                 num_groups = prop->length / sizeof(u32) / 2;
1170         }
1171
1172         /* Channel is now open, advertise base set of intents */
1173         while (num_groups--) {
1174                 size = be32_to_cpup(val++);
1175                 num_intents = be32_to_cpup(val++);
1176                 while (num_intents--) {
1177                         intent = qcom_glink_alloc_intent(glink, channel, size,
1178                                                          true);
1179                         if (!intent)
1180                                 break;
1181
1182                         qcom_glink_advertise_intent(glink, channel, intent);
1183                 }
1184         }
1185         return 0;
1186 }
1187
1188 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1189 {
1190         struct glink_channel *channel = to_glink_channel(ept);
1191         struct qcom_glink *glink = channel->glink;
1192         unsigned long flags;
1193
1194         spin_lock_irqsave(&channel->recv_lock, flags);
1195         channel->ept.cb = NULL;
1196         spin_unlock_irqrestore(&channel->recv_lock, flags);
1197
1198         /* Decouple the potential rpdev from the channel */
1199         channel->rpdev = NULL;
1200
1201         qcom_glink_send_close_req(glink, channel);
1202 }
1203
1204 static int qcom_glink_request_intent(struct qcom_glink *glink,
1205                                      struct glink_channel *channel,
1206                                      size_t size)
1207 {
1208         struct {
1209                 u16 id;
1210                 u16 cid;
1211                 u32 size;
1212         } __packed cmd;
1213
1214         int ret;
1215
1216         mutex_lock(&channel->intent_req_lock);
1217
1218         reinit_completion(&channel->intent_req_comp);
1219
1220         cmd.id = RPM_CMD_RX_INTENT_REQ;
1221         cmd.cid = channel->lcid;
1222         cmd.size = size;
1223
1224         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1225         if (ret)
1226                 goto unlock;
1227
1228         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1229         if (!ret) {
1230                 dev_err(glink->dev, "intent request timed out\n");
1231                 ret = -ETIMEDOUT;
1232         } else {
1233                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1234         }
1235
1236 unlock:
1237         mutex_unlock(&channel->intent_req_lock);
1238         return ret;
1239 }
1240
1241 static int __qcom_glink_send(struct glink_channel *channel,
1242                              void *data, int len, bool wait)
1243 {
1244         struct qcom_glink *glink = channel->glink;
1245         struct glink_core_rx_intent *intent = NULL;
1246         struct glink_core_rx_intent *tmp;
1247         int iid = 0;
1248         struct {
1249                 struct glink_msg msg;
1250                 __le32 chunk_size;
1251                 __le32 left_size;
1252         } __packed req;
1253         int ret;
1254         unsigned long flags;
1255
1256         if (!glink->intentless) {
1257                 while (!intent) {
1258                         spin_lock_irqsave(&channel->intent_lock, flags);
1259                         idr_for_each_entry(&channel->riids, tmp, iid) {
1260                                 if (tmp->size >= len && !tmp->in_use) {
1261                                         if (!intent)
1262                                                 intent = tmp;
1263                                         else if (intent->size > tmp->size)
1264                                                 intent = tmp;
1265                                         if (intent->size == len)
1266                                                 break;
1267                                 }
1268                         }
1269                         if (intent)
1270                                 intent->in_use = true;
1271                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1272
1273                         /* We found an available intent */
1274                         if (intent)
1275                                 break;
1276
1277                         if (!wait)
1278                                 return -EBUSY;
1279
1280                         ret = qcom_glink_request_intent(glink, channel, len);
1281                         if (ret < 0)
1282                                 return ret;
1283                 }
1284
1285                 iid = intent->id;
1286         }
1287
1288         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1289         req.msg.param1 = cpu_to_le16(channel->lcid);
1290         req.msg.param2 = cpu_to_le32(iid);
1291         req.chunk_size = cpu_to_le32(len);
1292         req.left_size = cpu_to_le32(0);
1293
1294         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1295
1296         /* Mark intent available if we failed */
1297         if (ret && intent)
1298                 intent->in_use = false;
1299
1300         return ret;
1301 }
1302
1303 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1304 {
1305         struct glink_channel *channel = to_glink_channel(ept);
1306
1307         return __qcom_glink_send(channel, data, len, true);
1308 }
1309
1310 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1311 {
1312         struct glink_channel *channel = to_glink_channel(ept);
1313
1314         return __qcom_glink_send(channel, data, len, false);
1315 }
1316
1317 /*
1318  * Finds the device_node for the glink child interested in this channel.
1319  */
1320 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1321                                                     const char *channel)
1322 {
1323         struct device_node *child;
1324         const char *name;
1325         const char *key;
1326         int ret;
1327
1328         for_each_available_child_of_node(node, child) {
1329                 key = "qcom,glink-channels";
1330                 ret = of_property_read_string(child, key, &name);
1331                 if (ret)
1332                         continue;
1333
1334                 if (strcmp(name, channel) == 0)
1335                         return child;
1336         }
1337
1338         return NULL;
1339 }
1340
1341 static const struct rpmsg_device_ops glink_device_ops = {
1342         .create_ept = qcom_glink_create_ept,
1343         .announce_create = qcom_glink_announce_create,
1344 };
1345
1346 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1347         .destroy_ept = qcom_glink_destroy_ept,
1348         .send = qcom_glink_send,
1349         .trysend = qcom_glink_trysend,
1350 };
1351
1352 static void qcom_glink_rpdev_release(struct device *dev)
1353 {
1354         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1355         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1356
1357         channel->rpdev = NULL;
1358         kfree(rpdev);
1359 }
1360
1361 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1362                               char *name)
1363 {
1364         struct glink_channel *channel;
1365         struct rpmsg_device *rpdev;
1366         bool create_device = false;
1367         struct device_node *node;
1368         int lcid;
1369         int ret;
1370         unsigned long flags;
1371
1372         spin_lock_irqsave(&glink->idr_lock, flags);
1373         idr_for_each_entry(&glink->lcids, channel, lcid) {
1374                 if (!strcmp(channel->name, name))
1375                         break;
1376         }
1377         spin_unlock_irqrestore(&glink->idr_lock, flags);
1378
1379         if (!channel) {
1380                 channel = qcom_glink_alloc_channel(glink, name);
1381                 if (IS_ERR(channel))
1382                         return PTR_ERR(channel);
1383
1384                 /* The opening dance was initiated by the remote */
1385                 create_device = true;
1386         }
1387
1388         spin_lock_irqsave(&glink->idr_lock, flags);
1389         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1390         if (ret < 0) {
1391                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1392                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1393                 goto free_channel;
1394         }
1395         channel->rcid = ret;
1396         spin_unlock_irqrestore(&glink->idr_lock, flags);
1397
1398         complete(&channel->open_req);
1399
1400         if (create_device) {
1401                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1402                 if (!rpdev) {
1403                         ret = -ENOMEM;
1404                         goto rcid_remove;
1405                 }
1406
1407                 rpdev->ept = &channel->ept;
1408                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1409                 rpdev->src = RPMSG_ADDR_ANY;
1410                 rpdev->dst = RPMSG_ADDR_ANY;
1411                 rpdev->ops = &glink_device_ops;
1412
1413                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1414                 rpdev->dev.of_node = node;
1415                 rpdev->dev.parent = glink->dev;
1416                 rpdev->dev.release = qcom_glink_rpdev_release;
1417
1418                 ret = rpmsg_register_device(rpdev);
1419                 if (ret)
1420                         goto free_rpdev;
1421
1422                 channel->rpdev = rpdev;
1423         }
1424
1425         return 0;
1426
1427 free_rpdev:
1428         kfree(rpdev);
1429 rcid_remove:
1430         spin_lock_irqsave(&glink->idr_lock, flags);
1431         idr_remove(&glink->rcids, channel->rcid);
1432         channel->rcid = 0;
1433         spin_unlock_irqrestore(&glink->idr_lock, flags);
1434 free_channel:
1435         /* Release the reference, iff we took it */
1436         if (create_device)
1437                 kref_put(&channel->refcount, qcom_glink_channel_release);
1438
1439         return ret;
1440 }
1441
1442 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1443 {
1444         struct rpmsg_channel_info chinfo;
1445         struct glink_channel *channel;
1446         unsigned long flags;
1447
1448         spin_lock_irqsave(&glink->idr_lock, flags);
1449         channel = idr_find(&glink->rcids, rcid);
1450         spin_unlock_irqrestore(&glink->idr_lock, flags);
1451         if (WARN(!channel, "close request on unknown channel\n"))
1452                 return;
1453
1454         /* cancel pending rx_done work */
1455         cancel_work_sync(&channel->intent_work);
1456
1457         if (channel->rpdev) {
1458                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1459                 chinfo.src = RPMSG_ADDR_ANY;
1460                 chinfo.dst = RPMSG_ADDR_ANY;
1461
1462                 rpmsg_unregister_device(glink->dev, &chinfo);
1463         }
1464
1465         qcom_glink_send_close_ack(glink, channel->rcid);
1466
1467         spin_lock_irqsave(&glink->idr_lock, flags);
1468         idr_remove(&glink->rcids, channel->rcid);
1469         channel->rcid = 0;
1470         spin_unlock_irqrestore(&glink->idr_lock, flags);
1471
1472         kref_put(&channel->refcount, qcom_glink_channel_release);
1473 }
1474
1475 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1476 {
1477         struct glink_channel *channel;
1478         unsigned long flags;
1479
1480         spin_lock_irqsave(&glink->idr_lock, flags);
1481         channel = idr_find(&glink->lcids, lcid);
1482         if (WARN(!channel, "close ack on unknown channel\n")) {
1483                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1484                 return;
1485         }
1486
1487         idr_remove(&glink->lcids, channel->lcid);
1488         channel->lcid = 0;
1489         spin_unlock_irqrestore(&glink->idr_lock, flags);
1490
1491         kref_put(&channel->refcount, qcom_glink_channel_release);
1492 }
1493
1494 static void qcom_glink_work(struct work_struct *work)
1495 {
1496         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1497                                                 rx_work);
1498         struct glink_defer_cmd *dcmd;
1499         struct glink_msg *msg;
1500         unsigned long flags;
1501         unsigned int param1;
1502         unsigned int param2;
1503         unsigned int cmd;
1504
1505         for (;;) {
1506                 spin_lock_irqsave(&glink->rx_lock, flags);
1507                 if (list_empty(&glink->rx_queue)) {
1508                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1509                         break;
1510                 }
1511                 dcmd = list_first_entry(&glink->rx_queue,
1512                                         struct glink_defer_cmd, node);
1513                 list_del(&dcmd->node);
1514                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1515
1516                 msg = &dcmd->msg;
1517                 cmd = le16_to_cpu(msg->cmd);
1518                 param1 = le16_to_cpu(msg->param1);
1519                 param2 = le32_to_cpu(msg->param2);
1520
1521                 switch (cmd) {
1522                 case RPM_CMD_VERSION:
1523                         qcom_glink_receive_version(glink, param1, param2);
1524                         break;
1525                 case RPM_CMD_VERSION_ACK:
1526                         qcom_glink_receive_version_ack(glink, param1, param2);
1527                         break;
1528                 case RPM_CMD_OPEN:
1529                         qcom_glink_rx_open(glink, param1, msg->data);
1530                         break;
1531                 case RPM_CMD_CLOSE:
1532                         qcom_glink_rx_close(glink, param1);
1533                         break;
1534                 case RPM_CMD_CLOSE_ACK:
1535                         qcom_glink_rx_close_ack(glink, param1);
1536                         break;
1537                 case RPM_CMD_RX_INTENT_REQ:
1538                         qcom_glink_handle_intent_req(glink, param1, param2);
1539                         break;
1540                 default:
1541                         WARN(1, "Unknown defer object %d\n", cmd);
1542                         break;
1543                 }
1544
1545                 kfree(dcmd);
1546         }
1547 }
1548
1549 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1550                                            unsigned long features,
1551                                            struct qcom_glink_pipe *rx,
1552                                            struct qcom_glink_pipe *tx,
1553                                            bool intentless)
1554 {
1555         int irq;
1556         int ret;
1557         struct qcom_glink *glink;
1558
1559         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1560         if (!glink)
1561                 return ERR_PTR(-ENOMEM);
1562
1563         glink->dev = dev;
1564         glink->tx_pipe = tx;
1565         glink->rx_pipe = rx;
1566
1567         glink->features = features;
1568         glink->intentless = intentless;
1569
1570         mutex_init(&glink->tx_lock);
1571         spin_lock_init(&glink->rx_lock);
1572         INIT_LIST_HEAD(&glink->rx_queue);
1573         INIT_WORK(&glink->rx_work, qcom_glink_work);
1574
1575         spin_lock_init(&glink->idr_lock);
1576         idr_init(&glink->lcids);
1577         idr_init(&glink->rcids);
1578
1579         glink->mbox_client.dev = dev;
1580         glink->mbox_client.knows_txdone = true;
1581         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1582         if (IS_ERR(glink->mbox_chan)) {
1583                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1584                         dev_err(dev, "failed to acquire IPC channel\n");
1585                 return ERR_CAST(glink->mbox_chan);
1586         }
1587
1588         irq = of_irq_get(dev->of_node, 0);
1589         ret = devm_request_irq(dev, irq,
1590                                qcom_glink_native_intr,
1591                                IRQF_NO_SUSPEND | IRQF_SHARED,
1592                                "glink-native", glink);
1593         if (ret) {
1594                 dev_err(dev, "failed to request IRQ\n");
1595                 return ERR_PTR(ret);
1596         }
1597
1598         glink->irq = irq;
1599
1600         ret = qcom_glink_send_version(glink);
1601         if (ret)
1602                 return ERR_PTR(ret);
1603
1604         return glink;
1605 }
1606 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1607
1608 static int qcom_glink_remove_device(struct device *dev, void *data)
1609 {
1610         device_unregister(dev);
1611
1612         return 0;
1613 }
1614
1615 void qcom_glink_native_remove(struct qcom_glink *glink)
1616 {
1617         struct glink_channel *channel;
1618         int cid;
1619         int ret;
1620         unsigned long flags;
1621
1622         disable_irq(glink->irq);
1623         cancel_work_sync(&glink->rx_work);
1624
1625         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1626         if (ret)
1627                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1628
1629         spin_lock_irqsave(&glink->idr_lock, flags);
1630         /* Release any defunct local channels, waiting for close-ack */
1631         idr_for_each_entry(&glink->lcids, channel, cid)
1632                 kref_put(&channel->refcount, qcom_glink_channel_release);
1633
1634         idr_destroy(&glink->lcids);
1635         idr_destroy(&glink->rcids);
1636         spin_unlock_irqrestore(&glink->idr_lock, flags);
1637         mbox_free_channel(glink->mbox_chan);
1638 }
1639 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1640
1641 void qcom_glink_native_unregister(struct qcom_glink *glink)
1642 {
1643         device_unregister(glink->dev);
1644 }
1645 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1646
1647 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1648 MODULE_LICENSE("GPL v2");