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  * @tx_avail_notify: Waitqueue for pending tx tasks
  96  * @sent_read_notify: flag to check cmd sent or not
  97  */
  98 struct qcom_glink {
  99         struct device *dev;
 100
 101         const char *name;
 102
 103         struct mbox_client mbox_client;
 104         struct mbox_chan *mbox_chan;
 105
 106         struct qcom_glink_pipe *rx_pipe;
 107         struct qcom_glink_pipe *tx_pipe;
 108
 109         int irq;
 110
 111         struct work_struct rx_work;
 112         spinlock_t rx_lock;
 113         struct list_head rx_queue;
 114
 115         spinlock_t tx_lock;
 116
 117         spinlock_t idr_lock;
 118         struct idr lcids;
 119         struct idr rcids;
 120         unsigned long features;
 121
 122         bool intentless;
 123         wait_queue_head_t tx_avail_notify;
 124         bool sent_read_notify;
 125 };
 126
 127 enum {
 128         GLINK_STATE_CLOSED,
 129         GLINK_STATE_OPENING,
 130         GLINK_STATE_OPEN,
 131         GLINK_STATE_CLOSING,
 132 };
 133
 134 /**
 135  * struct glink_channel - internal representation of a channel
 136  * @rpdev:      rpdev reference, only used for primary endpoints
 137  * @ept:        rpmsg endpoint this channel is associated with
 138  * @glink:      qcom_glink context handle
 139  * @refcount:   refcount for the channel object
 140  * @recv_lock:  guard for @ept.cb
 141  * @name:       unique channel name/identifier
 142  * @lcid:       channel id, in local space
 143  * @rcid:       channel id, in remote space
 144  * @intent_lock: lock for protection of @liids, @riids
 145  * @liids:      idr of all local intents
 146  * @riids:      idr of all remote intents
 147  * @intent_work: worker responsible for transmitting rx_done packets
 148  * @done_intents: list of intents that needs to be announced rx_done
 149  * @buf:        receive buffer, for gathering fragments
 150  * @buf_offset: write offset in @buf
 151  * @buf_size:   size of current @buf
 152  * @open_ack:   completed once remote has acked the open-request
 153  * @open_req:   completed once open-request has been received
 154  * @intent_req_lock: Synchronises multiple intent requests
 155  * @intent_req_result: Result of intent request
 156  * @intent_req_comp: Completion for intent_req signalling
 157  */
 158 struct glink_channel {
 159         struct rpmsg_endpoint ept;
 160
 161         struct rpmsg_device *rpdev;
 162         struct qcom_glink *glink;
 163
 164         struct kref refcount;
 165
 166         spinlock_t recv_lock;
 167
 168         char *name;
 169         unsigned int lcid;
 170         unsigned int rcid;
 171
 172         spinlock_t intent_lock;
 173         struct idr liids;
 174         struct idr riids;
 175         struct work_struct intent_work;
 176         struct list_head done_intents;
 177
 178         struct glink_core_rx_intent *buf;
 179         int buf_offset;
 180         int buf_size;
 181
 182         struct completion open_ack;
 183         struct completion open_req;
 184
 185         struct mutex intent_req_lock;
 186         bool intent_req_result;
 187         struct completion intent_req_comp;
 188 };
 189
 190 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 191
 192 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 193
 194 #define RPM_CMD_VERSION                 0
 195 #define RPM_CMD_VERSION_ACK             1
 196 #define RPM_CMD_OPEN                    2
 197 #define RPM_CMD_CLOSE                   3
 198 #define RPM_CMD_OPEN_ACK                4
 199 #define RPM_CMD_INTENT                  5
 200 #define RPM_CMD_RX_DONE                 6
 201 #define RPM_CMD_RX_INTENT_REQ           7
 202 #define RPM_CMD_RX_INTENT_REQ_ACK       8
 203 #define RPM_CMD_TX_DATA                 9
 204 #define RPM_CMD_CLOSE_ACK               11
 205 #define RPM_CMD_TX_DATA_CONT            12
 206 #define RPM_CMD_READ_NOTIF              13
 207 #define RPM_CMD_RX_DONE_W_REUSE         14
 208
 209 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 210
 211 static void qcom_glink_rx_done_work(struct work_struct *work);
 212
 213 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 214                                                       const char *name)
 215 {
 216         struct glink_channel *channel;
 217
 218         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 219         if (!channel)
 220                 return ERR_PTR(-ENOMEM);
 221
 222         /* Setup glink internal glink_channel data */
 223         spin_lock_init(&channel->recv_lock);
 224         spin_lock_init(&channel->intent_lock);
 225         mutex_init(&channel->intent_req_lock);
 226
 227         channel->glink = glink;
 228         channel->name = kstrdup(name, GFP_KERNEL);
 229
 230         init_completion(&channel->open_req);
 231         init_completion(&channel->open_ack);
 232         init_completion(&channel->intent_req_comp);
 233
 234         INIT_LIST_HEAD(&channel->done_intents);
 235         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 236
 237         idr_init(&channel->liids);
 238         idr_init(&channel->riids);
 239         kref_init(&channel->refcount);
 240
 241         return channel;
 242 }
 243
 244 static void qcom_glink_channel_release(struct kref *ref)
 245 {
 246         struct glink_channel *channel = container_of(ref, struct glink_channel,
 247                                                      refcount);
 248         struct glink_core_rx_intent *intent;
 249         struct glink_core_rx_intent *tmp;
 250         unsigned long flags;
 251         int iid;
 252
 253         /* cancel pending rx_done work */
 254         cancel_work_sync(&channel->intent_work);
 255
 256         spin_lock_irqsave(&channel->intent_lock, flags);
 257         /* Free all non-reuse intents pending rx_done work */
 258         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 259                 if (!intent->reuse) {
 260                         kfree(intent->data);
 261                         kfree(intent);
 262                 }
 263         }
 264
 265         idr_for_each_entry(&channel->liids, tmp, iid) {
 266                 kfree(tmp->data);
 267                 kfree(tmp);
 268         }
 269         idr_destroy(&channel->liids);
 270
 271         idr_for_each_entry(&channel->riids, tmp, iid)
 272                 kfree(tmp);
 273         idr_destroy(&channel->riids);
 274         spin_unlock_irqrestore(&channel->intent_lock, flags);
 275
 276         kfree(channel->name);
 277         kfree(channel);
 278 }
 279
 280 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 281 {
 282         return glink->rx_pipe->avail(glink->rx_pipe);
 283 }
 284
 285 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 286                                void *data, unsigned int offset, size_t count)
 287 {
 288         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 289 }
 290
 291 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 292 {
 293         glink->rx_pipe->advance(glink->rx_pipe, count);
 294 }
 295
 296 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 297 {
 298         return glink->tx_pipe->avail(glink->tx_pipe);
 299 }
 300
 301 static void qcom_glink_tx_write(struct qcom_glink *glink,
 302                                 const void *hdr, size_t hlen,
 303                                 const void *data, size_t dlen)
 304 {
 305         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 306 }
 307
 308 static void qcom_glink_send_read_notify(struct qcom_glink *glink)
 309 {
 310         struct glink_msg msg;
 311
 312         msg.cmd = cpu_to_le16(RPM_CMD_READ_NOTIF);
 313         msg.param1 = 0;
 314         msg.param2 = 0;
 315
 316         qcom_glink_tx_write(glink, &msg, sizeof(msg), NULL, 0);
 317
 318         mbox_send_message(glink->mbox_chan, NULL);
 319         mbox_client_txdone(glink->mbox_chan, 0);
 320 }
 321
 322 static int qcom_glink_tx(struct qcom_glink *glink,
 323                          const void *hdr, size_t hlen,
 324                          const void *data, size_t dlen, bool wait)
 325 {
 326         unsigned int tlen = hlen + dlen;
 327         unsigned long flags;
 328         int ret = 0;
 329
 330         /* Reject packets that are too big */
 331         if (tlen >= glink->tx_pipe->length)
 332                 return -EINVAL;
 333
 334         spin_lock_irqsave(&glink->tx_lock, flags);
 335
 336         while (qcom_glink_tx_avail(glink) < tlen) {
 337                 if (!wait) {
 338                         ret = -EAGAIN;
 339                         goto out;
 340                 }
 341
 342                 if (!glink->sent_read_notify) {
 343                         glink->sent_read_notify = true;
 344                         qcom_glink_send_read_notify(glink);
 345                 }
 346
 347                 /* Wait without holding the tx_lock */
 348                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 349
 350                 wait_event_timeout(glink->tx_avail_notify,
 351                                    qcom_glink_tx_avail(glink) >= tlen, 10 * HZ);
 352
 353                 spin_lock_irqsave(&glink->tx_lock, flags);
 354
 355                 if (qcom_glink_tx_avail(glink) >= tlen)
 356                         glink->sent_read_notify = false;
 357         }
 358
 359         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 360
 361         mbox_send_message(glink->mbox_chan, NULL);
 362         mbox_client_txdone(glink->mbox_chan, 0);
 363
 364 out:
 365         spin_unlock_irqrestore(&glink->tx_lock, flags);
 366
 367         return ret;
 368 }
 369
 370 static int qcom_glink_send_version(struct qcom_glink *glink)
 371 {
 372         struct glink_msg msg;
 373
 374         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 375         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 376         msg.param2 = cpu_to_le32(glink->features);
 377
 378         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 379 }
 380
 381 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 382 {
 383         struct glink_msg msg;
 384
 385         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 386         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 387         msg.param2 = cpu_to_le32(glink->features);
 388
 389         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 390 }
 391
 392 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 393                                      struct glink_channel *channel)
 394 {
 395         struct glink_msg msg;
 396
 397         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 398         msg.param1 = cpu_to_le16(channel->rcid);
 399         msg.param2 = cpu_to_le32(0);
 400
 401         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 402 }
 403
 404 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 405                                              unsigned int cid, bool granted)
 406 {
 407         struct glink_channel *channel;
 408         unsigned long flags;
 409
 410         spin_lock_irqsave(&glink->idr_lock, flags);
 411         channel = idr_find(&glink->rcids, cid);
 412         spin_unlock_irqrestore(&glink->idr_lock, flags);
 413         if (!channel) {
 414                 dev_err(glink->dev, "unable to find channel\n");
 415                 return;
 416         }
 417
 418         channel->intent_req_result = granted;
 419         complete(&channel->intent_req_comp);
 420 }
 421
 422 /**
 423  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 424  * @glink: Ptr to the glink edge
 425  * @channel: Ptr to the channel that the open req is sent
 426  *
 427  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 428  * Will return with refcount held, regardless of outcome.
 429  *
 430  * Return: 0 on success, negative errno otherwise.
 431  */
 432 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 433                                     struct glink_channel *channel)
 434 {
 435         struct {
 436                 struct glink_msg msg;
 437                 u8 name[GLINK_NAME_SIZE];
 438         } __packed req;
 439         int name_len = strlen(channel->name) + 1;
 440         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 441         int ret;
 442         unsigned long flags;
 443
 444         kref_get(&channel->refcount);
 445
 446         spin_lock_irqsave(&glink->idr_lock, flags);
 447         ret = idr_alloc_cyclic(&glink->lcids, channel,
 448                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 449                                GFP_ATOMIC);
 450         spin_unlock_irqrestore(&glink->idr_lock, flags);
 451         if (ret < 0)
 452                 return ret;
 453
 454         channel->lcid = ret;
 455
 456         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 457         req.msg.param1 = cpu_to_le16(channel->lcid);
 458         req.msg.param2 = cpu_to_le32(name_len);
 459         strcpy(req.name, channel->name);
 460
 461         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 462         if (ret)
 463                 goto remove_idr;
 464
 465         return 0;
 466
 467 remove_idr:
 468         spin_lock_irqsave(&glink->idr_lock, flags);
 469         idr_remove(&glink->lcids, channel->lcid);
 470         channel->lcid = 0;
 471         spin_unlock_irqrestore(&glink->idr_lock, flags);
 472
 473         return ret;
 474 }
 475
 476 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 477                                       struct glink_channel *channel)
 478 {
 479         struct glink_msg req;
 480
 481         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 482         req.param1 = cpu_to_le16(channel->lcid);
 483         req.param2 = 0;
 484
 485         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 486 }
 487
 488 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 489                                       unsigned int rcid)
 490 {
 491         struct glink_msg req;
 492
 493         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 494         req.param1 = cpu_to_le16(rcid);
 495         req.param2 = 0;
 496
 497         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 498 }
 499
 500 static void qcom_glink_rx_done_work(struct work_struct *work)
 501 {
 502         struct glink_channel *channel = container_of(work, struct glink_channel,
 503                                                      intent_work);
 504         struct qcom_glink *glink = channel->glink;
 505         struct glink_core_rx_intent *intent, *tmp;
 506         struct {
 507                 u16 id;
 508                 u16 lcid;
 509                 u32 liid;
 510         } __packed cmd;
 511
 512         unsigned int cid = channel->lcid;
 513         unsigned int iid;
 514         bool reuse;
 515         unsigned long flags;
 516
 517         spin_lock_irqsave(&channel->intent_lock, flags);
 518         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 519                 list_del(&intent->node);
 520                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 521                 iid = intent->id;
 522                 reuse = intent->reuse;
 523
 524                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 525                 cmd.lcid = cid;
 526                 cmd.liid = iid;
 527
 528                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 529                 if (!reuse) {
 530                         kfree(intent->data);
 531                         kfree(intent);
 532                 }
 533                 spin_lock_irqsave(&channel->intent_lock, flags);
 534         }
 535         spin_unlock_irqrestore(&channel->intent_lock, flags);
 536 }
 537
 538 static void qcom_glink_rx_done(struct qcom_glink *glink,
 539                                struct glink_channel *channel,
 540                                struct glink_core_rx_intent *intent)
 541 {
 542         /* We don't send RX_DONE to intentless systems */
 543         if (glink->intentless) {
 544                 kfree(intent->data);
 545                 kfree(intent);
 546                 return;
 547         }
 548
 549         /* Take it off the tree of receive intents */
 550         if (!intent->reuse) {
 551                 spin_lock(&channel->intent_lock);
 552                 idr_remove(&channel->liids, intent->id);
 553                 spin_unlock(&channel->intent_lock);
 554         }
 555
 556         /* Schedule the sending of a rx_done indication */
 557         spin_lock(&channel->intent_lock);
 558         list_add_tail(&intent->node, &channel->done_intents);
 559         spin_unlock(&channel->intent_lock);
 560
 561         schedule_work(&channel->intent_work);
 562 }
 563
 564 /**
 565  * qcom_glink_receive_version() - receive version/features from remote system
 566  *
 567  * @glink:      pointer to transport interface
 568  * @version:    remote version
 569  * @features:   remote features
 570  *
 571  * This function is called in response to a remote-initiated version/feature
 572  * negotiation sequence.
 573  */
 574 static void qcom_glink_receive_version(struct qcom_glink *glink,
 575                                        u32 version,
 576                                        u32 features)
 577 {
 578         switch (version) {
 579         case 0:
 580                 break;
 581         case GLINK_VERSION_1:
 582                 glink->features &= features;
 583                 fallthrough;
 584         default:
 585                 qcom_glink_send_version_ack(glink);
 586                 break;
 587         }
 588 }
 589
 590 /**
 591  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 592  *
 593  * @glink:      pointer to transport interface
 594  * @version:    remote version response
 595  * @features:   remote features response
 596  *
 597  * This function is called in response to a local-initiated version/feature
 598  * negotiation sequence and is the counter-offer from the remote side based
 599  * upon the initial version and feature set requested.
 600  */
 601 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 602                                            u32 version,
 603                                            u32 features)
 604 {
 605         switch (version) {
 606         case 0:
 607                 /* Version negotiation failed */
 608                 break;
 609         case GLINK_VERSION_1:
 610                 if (features == glink->features)
 611                         break;
 612
 613                 glink->features &= features;
 614                 fallthrough;
 615         default:
 616                 qcom_glink_send_version(glink);
 617                 break;
 618         }
 619 }
 620
 621 /**
 622  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 623  *      wire format and transmit
 624  * @glink:      The transport to transmit on.
 625  * @channel:    The glink channel
 626  * @granted:    The request response to encode.
 627  *
 628  * Return: 0 on success or standard Linux error code.
 629  */
 630 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 631                                           struct glink_channel *channel,
 632                                           bool granted)
 633 {
 634         struct glink_msg msg;
 635
 636         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 637         msg.param1 = cpu_to_le16(channel->lcid);
 638         msg.param2 = cpu_to_le32(granted);
 639
 640         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 641
 642         return 0;
 643 }
 644
 645 /**
 646  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 647  *                         transmit
 648  * @glink:      The transport to transmit on.
 649  * @channel:    The local channel
 650  * @intent:     The intent to pass on to remote.
 651  *
 652  * Return: 0 on success or standard Linux error code.
 653  */
 654 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 655                                        struct glink_channel *channel,
 656                                        struct glink_core_rx_intent *intent)
 657 {
 658         struct command {
 659                 __le16 id;
 660                 __le16 lcid;
 661                 __le32 count;
 662                 __le32 size;
 663                 __le32 liid;
 664         } __packed;
 665         struct command cmd;
 666
 667         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 668         cmd.lcid = cpu_to_le16(channel->lcid);
 669         cmd.count = cpu_to_le32(1);
 670         cmd.size = cpu_to_le32(intent->size);
 671         cmd.liid = cpu_to_le32(intent->id);
 672
 673         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 674
 675         return 0;
 676 }
 677
 678 static struct glink_core_rx_intent *
 679 qcom_glink_alloc_intent(struct qcom_glink *glink,
 680                         struct glink_channel *channel,
 681                         size_t size,
 682                         bool reuseable)
 683 {
 684         struct glink_core_rx_intent *intent;
 685         int ret;
 686         unsigned long flags;
 687
 688         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 689         if (!intent)
 690                 return NULL;
 691
 692         intent->data = kzalloc(size, GFP_KERNEL);
 693         if (!intent->data)
 694                 goto free_intent;
 695
 696         spin_lock_irqsave(&channel->intent_lock, flags);
 697         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 698         if (ret < 0) {
 699                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 700                 goto free_data;
 701         }
 702         spin_unlock_irqrestore(&channel->intent_lock, flags);
 703
 704         intent->id = ret;
 705         intent->size = size;
 706         intent->reuse = reuseable;
 707
 708         return intent;
 709
 710 free_data:
 711         kfree(intent->data);
 712 free_intent:
 713         kfree(intent);
 714         return NULL;
 715 }
 716
 717 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 718                                       u32 cid, uint32_t iid,
 719                                       bool reuse)
 720 {
 721         struct glink_core_rx_intent *intent;
 722         struct glink_channel *channel;
 723         unsigned long flags;
 724
 725         spin_lock_irqsave(&glink->idr_lock, flags);
 726         channel = idr_find(&glink->rcids, cid);
 727         spin_unlock_irqrestore(&glink->idr_lock, flags);
 728         if (!channel) {
 729                 dev_err(glink->dev, "invalid channel id received\n");
 730                 return;
 731         }
 732
 733         spin_lock_irqsave(&channel->intent_lock, flags);
 734         intent = idr_find(&channel->riids, iid);
 735
 736         if (!intent) {
 737                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 738                 dev_err(glink->dev, "invalid intent id received\n");
 739                 return;
 740         }
 741
 742         intent->in_use = false;
 743
 744         if (!reuse) {
 745                 idr_remove(&channel->riids, intent->id);
 746                 kfree(intent);
 747         }
 748         spin_unlock_irqrestore(&channel->intent_lock, flags);
 749 }
 750
 751 /**
 752  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 753  *                                          from remote side
 754  * @glink:      Pointer to the transport interface
 755  * @cid:        Remote channel ID
 756  * @size:       size of the intent
 757  *
 758  * The function searches for the local channel to which the request for
 759  * rx_intent has arrived and allocates and notifies the remote back
 760  */
 761 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 762                                          u32 cid, size_t size)
 763 {
 764         struct glink_core_rx_intent *intent;
 765         struct glink_channel *channel;
 766         unsigned long flags;
 767
 768         spin_lock_irqsave(&glink->idr_lock, flags);
 769         channel = idr_find(&glink->rcids, cid);
 770         spin_unlock_irqrestore(&glink->idr_lock, flags);
 771
 772         if (!channel) {
 773                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 774                 return;
 775         }
 776
 777         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 778         if (intent)
 779                 qcom_glink_advertise_intent(glink, channel, intent);
 780
 781         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 782 }
 783
 784 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 785 {
 786         struct glink_defer_cmd *dcmd;
 787
 788         extra = ALIGN(extra, 8);
 789
 790         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 791                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 792                 return -ENXIO;
 793         }
 794
 795         dcmd = kzalloc(struct_size(dcmd, data, extra), GFP_ATOMIC);
 796         if (!dcmd)
 797                 return -ENOMEM;
 798
 799         INIT_LIST_HEAD(&dcmd->node);
 800
 801         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 802
 803         spin_lock(&glink->rx_lock);
 804         list_add_tail(&dcmd->node, &glink->rx_queue);
 805         spin_unlock(&glink->rx_lock);
 806
 807         schedule_work(&glink->rx_work);
 808         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 809
 810         return 0;
 811 }
 812
 813 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 814 {
 815         struct glink_core_rx_intent *intent;
 816         struct glink_channel *channel;
 817         struct {
 818                 struct glink_msg msg;
 819                 __le32 chunk_size;
 820                 __le32 left_size;
 821         } __packed hdr;
 822         unsigned int chunk_size;
 823         unsigned int left_size;
 824         unsigned int rcid;
 825         unsigned int liid;
 826         int ret = 0;
 827         unsigned long flags;
 828
 829         if (avail < sizeof(hdr)) {
 830                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 831                 return -EAGAIN;
 832         }
 833
 834         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 835         chunk_size = le32_to_cpu(hdr.chunk_size);
 836         left_size = le32_to_cpu(hdr.left_size);
 837
 838         if (avail < sizeof(hdr) + chunk_size) {
 839                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 840                 return -EAGAIN;
 841         }
 842
 843         rcid = le16_to_cpu(hdr.msg.param1);
 844         spin_lock_irqsave(&glink->idr_lock, flags);
 845         channel = idr_find(&glink->rcids, rcid);
 846         spin_unlock_irqrestore(&glink->idr_lock, flags);
 847         if (!channel) {
 848                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 849
 850                 /* Drop the message */
 851                 goto advance_rx;
 852         }
 853
 854         if (glink->intentless) {
 855                 /* Might have an ongoing, fragmented, message to append */
 856                 if (!channel->buf) {
 857                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 858                         if (!intent)
 859                                 return -ENOMEM;
 860
 861                         intent->data = kmalloc(chunk_size + left_size,
 862                                                GFP_ATOMIC);
 863                         if (!intent->data) {
 864                                 kfree(intent);
 865                                 return -ENOMEM;
 866                         }
 867
 868                         intent->id = 0xbabababa;
 869                         intent->size = chunk_size + left_size;
 870                         intent->offset = 0;
 871
 872                         channel->buf = intent;
 873                 } else {
 874                         intent = channel->buf;
 875                 }
 876         } else {
 877                 liid = le32_to_cpu(hdr.msg.param2);
 878
 879                 spin_lock_irqsave(&channel->intent_lock, flags);
 880                 intent = idr_find(&channel->liids, liid);
 881                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 882
 883                 if (!intent) {
 884                         dev_err(glink->dev,
 885                                 "no intent found for channel %s intent %d",
 886                                 channel->name, liid);
 887                         ret = -ENOENT;
 888                         goto advance_rx;
 889                 }
 890         }
 891
 892         if (intent->size - intent->offset < chunk_size) {
 893                 dev_err(glink->dev, "Insufficient space in intent\n");
 894
 895                 /* The packet header lied, drop payload */
 896                 goto advance_rx;
 897         }
 898
 899         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 900                            sizeof(hdr), chunk_size);
 901         intent->offset += chunk_size;
 902
 903         /* Handle message when no fragments remain to be received */
 904         if (!left_size) {
 905                 spin_lock(&channel->recv_lock);
 906                 if (channel->ept.cb) {
 907                         channel->ept.cb(channel->ept.rpdev,
 908                                         intent->data,
 909                                         intent->offset,
 910                                         channel->ept.priv,
 911                                         RPMSG_ADDR_ANY);
 912                 }
 913                 spin_unlock(&channel->recv_lock);
 914
 915                 intent->offset = 0;
 916                 channel->buf = NULL;
 917
 918                 qcom_glink_rx_done(glink, channel, intent);
 919         }
 920
 921 advance_rx:
 922         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 923
 924         return ret;
 925 }
 926
 927 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 928                                      unsigned int cid,
 929                                      unsigned int count,
 930                                      size_t avail)
 931 {
 932         struct glink_core_rx_intent *intent;
 933         struct glink_channel *channel;
 934         struct intent_pair {
 935                 __le32 size;
 936                 __le32 iid;
 937         };
 938
 939         struct {
 940                 struct glink_msg msg;
 941                 struct intent_pair intents[];
 942         } __packed * msg;
 943
 944         const size_t msglen = struct_size(msg, intents, count);
 945         int ret;
 946         int i;
 947         unsigned long flags;
 948
 949         if (avail < msglen) {
 950                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 951                 return;
 952         }
 953
 954         spin_lock_irqsave(&glink->idr_lock, flags);
 955         channel = idr_find(&glink->rcids, cid);
 956         spin_unlock_irqrestore(&glink->idr_lock, flags);
 957         if (!channel) {
 958                 dev_err(glink->dev, "intents for non-existing channel\n");
 959                 return;
 960         }
 961
 962         msg = kmalloc(msglen, GFP_ATOMIC);
 963         if (!msg)
 964                 return;
 965
 966         qcom_glink_rx_peak(glink, msg, 0, msglen);
 967
 968         for (i = 0; i < count; ++i) {
 969                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 970                 if (!intent)
 971                         break;
 972
 973                 intent->id = le32_to_cpu(msg->intents[i].iid);
 974                 intent->size = le32_to_cpu(msg->intents[i].size);
 975
 976                 spin_lock_irqsave(&channel->intent_lock, flags);
 977                 ret = idr_alloc(&channel->riids, intent,
 978                                 intent->id, intent->id + 1, GFP_ATOMIC);
 979                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 980
 981                 if (ret < 0)
 982                         dev_err(glink->dev, "failed to store remote intent\n");
 983         }
 984
 985         kfree(msg);
 986         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 987 }
 988
 989 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 990 {
 991         struct glink_channel *channel;
 992
 993         spin_lock(&glink->idr_lock);
 994         channel = idr_find(&glink->lcids, lcid);
 995         spin_unlock(&glink->idr_lock);
 996         if (!channel) {
 997                 dev_err(glink->dev, "Invalid open ack packet\n");
 998                 return -EINVAL;
 999         }
1000
1001         complete_all(&channel->open_ack);
1002
1003         return 0;
1004 }
1005
1006 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
1007 {
1008         struct qcom_glink *glink = data;
1009         struct glink_msg msg;
1010         unsigned int param1;
1011         unsigned int param2;
1012         unsigned int avail;
1013         unsigned int cmd;
1014         int ret = 0;
1015
1016         /* To wakeup any blocking writers */
1017         wake_up_all(&glink->tx_avail_notify);
1018
1019         for (;;) {
1020                 avail = qcom_glink_rx_avail(glink);
1021                 if (avail < sizeof(msg))
1022                         break;
1023
1024                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
1025
1026                 cmd = le16_to_cpu(msg.cmd);
1027                 param1 = le16_to_cpu(msg.param1);
1028                 param2 = le32_to_cpu(msg.param2);
1029
1030                 switch (cmd) {
1031                 case RPM_CMD_VERSION:
1032                 case RPM_CMD_VERSION_ACK:
1033                 case RPM_CMD_CLOSE:
1034                 case RPM_CMD_CLOSE_ACK:
1035                 case RPM_CMD_RX_INTENT_REQ:
1036                         ret = qcom_glink_rx_defer(glink, 0);
1037                         break;
1038                 case RPM_CMD_OPEN_ACK:
1039                         ret = qcom_glink_rx_open_ack(glink, param1);
1040                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1041                         break;
1042                 case RPM_CMD_OPEN:
1043                         ret = qcom_glink_rx_defer(glink, param2);
1044                         break;
1045                 case RPM_CMD_TX_DATA:
1046                 case RPM_CMD_TX_DATA_CONT:
1047                         ret = qcom_glink_rx_data(glink, avail);
1048                         break;
1049                 case RPM_CMD_READ_NOTIF:
1050                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1051
1052                         mbox_send_message(glink->mbox_chan, NULL);
1053                         mbox_client_txdone(glink->mbox_chan, 0);
1054                         break;
1055                 case RPM_CMD_INTENT:
1056                         qcom_glink_handle_intent(glink, param1, param2, avail);
1057                         break;
1058                 case RPM_CMD_RX_DONE:
1059                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1060                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1061                         break;
1062                 case RPM_CMD_RX_DONE_W_REUSE:
1063                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1064                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1065                         break;
1066                 case RPM_CMD_RX_INTENT_REQ_ACK:
1067                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1068                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1069                         break;
1070                 default:
1071                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1072                         ret = -EINVAL;
1073                         break;
1074                 }
1075
1076                 if (ret)
1077                         break;
1078         }
1079
1080         return IRQ_HANDLED;
1081 }
1082
1083 /* Locally initiated rpmsg_create_ept */
1084 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1085                                                      const char *name)
1086 {
1087         struct glink_channel *channel;
1088         int ret;
1089         unsigned long flags;
1090
1091         channel = qcom_glink_alloc_channel(glink, name);
1092         if (IS_ERR(channel))
1093                 return ERR_CAST(channel);
1094
1095         ret = qcom_glink_send_open_req(glink, channel);
1096         if (ret)
1097                 goto release_channel;
1098
1099         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1100         if (!ret)
1101                 goto err_timeout;
1102
1103         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1104         if (!ret)
1105                 goto err_timeout;
1106
1107         qcom_glink_send_open_ack(glink, channel);
1108
1109         return channel;
1110
1111 err_timeout:
1112         /* qcom_glink_send_open_req() did register the channel in lcids*/
1113         spin_lock_irqsave(&glink->idr_lock, flags);
1114         idr_remove(&glink->lcids, channel->lcid);
1115         spin_unlock_irqrestore(&glink->idr_lock, flags);
1116
1117 release_channel:
1118         /* Release qcom_glink_send_open_req() reference */
1119         kref_put(&channel->refcount, qcom_glink_channel_release);
1120         /* Release qcom_glink_alloc_channel() reference */
1121         kref_put(&channel->refcount, qcom_glink_channel_release);
1122
1123         return ERR_PTR(-ETIMEDOUT);
1124 }
1125
1126 /* Remote initiated rpmsg_create_ept */
1127 static int qcom_glink_create_remote(struct qcom_glink *glink,
1128                                     struct glink_channel *channel)
1129 {
1130         int ret;
1131
1132         qcom_glink_send_open_ack(glink, channel);
1133
1134         ret = qcom_glink_send_open_req(glink, channel);
1135         if (ret)
1136                 goto close_link;
1137
1138         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1139         if (!ret) {
1140                 ret = -ETIMEDOUT;
1141                 goto close_link;
1142         }
1143
1144         return 0;
1145
1146 close_link:
1147         /*
1148          * Send a close request to "undo" our open-ack. The close-ack will
1149          * release qcom_glink_send_open_req() reference and the last reference
1150          * will be relesed after receiving remote_close or transport unregister
1151          * by calling qcom_glink_native_remove().
1152          */
1153         qcom_glink_send_close_req(glink, channel);
1154
1155         return ret;
1156 }
1157
1158 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1159                                                     rpmsg_rx_cb_t cb,
1160                                                     void *priv,
1161                                                     struct rpmsg_channel_info
1162                                                                         chinfo)
1163 {
1164         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1165         struct glink_channel *channel;
1166         struct qcom_glink *glink = parent->glink;
1167         struct rpmsg_endpoint *ept;
1168         const char *name = chinfo.name;
1169         int cid;
1170         int ret;
1171         unsigned long flags;
1172
1173         spin_lock_irqsave(&glink->idr_lock, flags);
1174         idr_for_each_entry(&glink->rcids, channel, cid) {
1175                 if (!strcmp(channel->name, name))
1176                         break;
1177         }
1178         spin_unlock_irqrestore(&glink->idr_lock, flags);
1179
1180         if (!channel) {
1181                 channel = qcom_glink_create_local(glink, name);
1182                 if (IS_ERR(channel))
1183                         return NULL;
1184         } else {
1185                 ret = qcom_glink_create_remote(glink, channel);
1186                 if (ret)
1187                         return NULL;
1188         }
1189
1190         ept = &channel->ept;
1191         ept->rpdev = rpdev;
1192         ept->cb = cb;
1193         ept->priv = priv;
1194         ept->ops = &glink_endpoint_ops;
1195
1196         return ept;
1197 }
1198
1199 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1200 {
1201         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1202         struct device_node *np = rpdev->dev.of_node;
1203         struct qcom_glink *glink = channel->glink;
1204         struct glink_core_rx_intent *intent;
1205         const struct property *prop = NULL;
1206         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1207         int num_intents;
1208         int num_groups = 1;
1209         __be32 *val = defaults;
1210         int size;
1211
1212         if (glink->intentless || !completion_done(&channel->open_ack))
1213                 return 0;
1214
1215         prop = of_find_property(np, "qcom,intents", NULL);
1216         if (prop) {
1217                 val = prop->value;
1218                 num_groups = prop->length / sizeof(u32) / 2;
1219         }
1220
1221         /* Channel is now open, advertise base set of intents */
1222         while (num_groups--) {
1223                 size = be32_to_cpup(val++);
1224                 num_intents = be32_to_cpup(val++);
1225                 while (num_intents--) {
1226                         intent = qcom_glink_alloc_intent(glink, channel, size,
1227                                                          true);
1228                         if (!intent)
1229                                 break;
1230
1231                         qcom_glink_advertise_intent(glink, channel, intent);
1232                 }
1233         }
1234         return 0;
1235 }
1236
1237 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1238 {
1239         struct glink_channel *channel = to_glink_channel(ept);
1240         struct qcom_glink *glink = channel->glink;
1241         unsigned long flags;
1242
1243         spin_lock_irqsave(&channel->recv_lock, flags);
1244         channel->ept.cb = NULL;
1245         spin_unlock_irqrestore(&channel->recv_lock, flags);
1246
1247         /* Decouple the potential rpdev from the channel */
1248         channel->rpdev = NULL;
1249
1250         qcom_glink_send_close_req(glink, channel);
1251 }
1252
1253 static int qcom_glink_request_intent(struct qcom_glink *glink,
1254                                      struct glink_channel *channel,
1255                                      size_t size)
1256 {
1257         struct {
1258                 u16 id;
1259                 u16 cid;
1260                 u32 size;
1261         } __packed cmd;
1262
1263         int ret;
1264
1265         mutex_lock(&channel->intent_req_lock);
1266
1267         reinit_completion(&channel->intent_req_comp);
1268
1269         cmd.id = RPM_CMD_RX_INTENT_REQ;
1270         cmd.cid = channel->lcid;
1271         cmd.size = size;
1272
1273         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1274         if (ret)
1275                 goto unlock;
1276
1277         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1278         if (!ret) {
1279                 dev_err(glink->dev, "intent request timed out\n");
1280                 ret = -ETIMEDOUT;
1281         } else {
1282                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1283         }
1284
1285 unlock:
1286         mutex_unlock(&channel->intent_req_lock);
1287         return ret;
1288 }
1289
1290 static int __qcom_glink_send(struct glink_channel *channel,
1291                              void *data, int len, bool wait)
1292 {
1293         struct qcom_glink *glink = channel->glink;
1294         struct glink_core_rx_intent *intent = NULL;
1295         struct glink_core_rx_intent *tmp;
1296         int iid = 0;
1297         struct {
1298                 struct glink_msg msg;
1299                 __le32 chunk_size;
1300                 __le32 left_size;
1301         } __packed req;
1302         int ret;
1303         unsigned long flags;
1304         int chunk_size = len;
1305         int left_size = 0;
1306
1307         if (!glink->intentless) {
1308                 while (!intent) {
1309                         spin_lock_irqsave(&channel->intent_lock, flags);
1310                         idr_for_each_entry(&channel->riids, tmp, iid) {
1311                                 if (tmp->size >= len && !tmp->in_use) {
1312                                         if (!intent)
1313                                                 intent = tmp;
1314                                         else if (intent->size > tmp->size)
1315                                                 intent = tmp;
1316                                         if (intent->size == len)
1317                                                 break;
1318                                 }
1319                         }
1320                         if (intent)
1321                                 intent->in_use = true;
1322                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1323
1324                         /* We found an available intent */
1325                         if (intent)
1326                                 break;
1327
1328                         if (!wait)
1329                                 return -EBUSY;
1330
1331                         ret = qcom_glink_request_intent(glink, channel, len);
1332                         if (ret < 0)
1333                                 return ret;
1334                 }
1335
1336                 iid = intent->id;
1337         }
1338
1339         if (wait && chunk_size > SZ_8K) {
1340                 chunk_size = SZ_8K;
1341                 left_size = len - chunk_size;
1342         }
1343         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1344         req.msg.param1 = cpu_to_le16(channel->lcid);
1345         req.msg.param2 = cpu_to_le32(iid);
1346         req.chunk_size = cpu_to_le32(chunk_size);
1347         req.left_size = cpu_to_le32(left_size);
1348
1349         ret = qcom_glink_tx(glink, &req, sizeof(req), data, chunk_size, wait);
1350
1351         /* Mark intent available if we failed */
1352         if (ret && intent) {
1353                 intent->in_use = false;
1354                 return ret;
1355         }
1356
1357         while (left_size > 0) {
1358                 data = (void *)((char *)data + chunk_size);
1359                 chunk_size = left_size;
1360                 if (chunk_size > SZ_8K)
1361                         chunk_size = SZ_8K;
1362                 left_size -= chunk_size;
1363
1364                 req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA_CONT);
1365                 req.msg.param1 = cpu_to_le16(channel->lcid);
1366                 req.msg.param2 = cpu_to_le32(iid);
1367                 req.chunk_size = cpu_to_le32(chunk_size);
1368                 req.left_size = cpu_to_le32(left_size);
1369
1370                 ret = qcom_glink_tx(glink, &req, sizeof(req), data,
1371                                     chunk_size, wait);
1372
1373                 /* Mark intent available if we failed */
1374                 if (ret && intent) {
1375                         intent->in_use = false;
1376                         break;
1377                 }
1378         }
1379         return ret;
1380 }
1381
1382 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1383 {
1384         struct glink_channel *channel = to_glink_channel(ept);
1385
1386         return __qcom_glink_send(channel, data, len, true);
1387 }
1388
1389 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1390 {
1391         struct glink_channel *channel = to_glink_channel(ept);
1392
1393         return __qcom_glink_send(channel, data, len, false);
1394 }
1395
1396 static int qcom_glink_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1397 {
1398         struct glink_channel *channel = to_glink_channel(ept);
1399
1400         return __qcom_glink_send(channel, data, len, true);
1401 }
1402
1403 static int qcom_glink_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1404 {
1405         struct glink_channel *channel = to_glink_channel(ept);
1406
1407         return __qcom_glink_send(channel, data, len, false);
1408 }
1409
1410 /*
1411  * Finds the device_node for the glink child interested in this channel.
1412  */
1413 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1414                                                     const char *channel)
1415 {
1416         struct device_node *child;
1417         const char *name;
1418         const char *key;
1419         int ret;
1420
1421         for_each_available_child_of_node(node, child) {
1422                 key = "qcom,glink-channels";
1423                 ret = of_property_read_string(child, key, &name);
1424                 if (ret)
1425                         continue;
1426
1427                 if (strcmp(name, channel) == 0)
1428                         return child;
1429         }
1430
1431         return NULL;
1432 }
1433
1434 static const struct rpmsg_device_ops glink_device_ops = {
1435         .create_ept = qcom_glink_create_ept,
1436         .announce_create = qcom_glink_announce_create,
1437 };
1438
1439 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1440         .destroy_ept = qcom_glink_destroy_ept,
1441         .send = qcom_glink_send,
1442         .sendto = qcom_glink_sendto,
1443         .trysend = qcom_glink_trysend,
1444         .trysendto = qcom_glink_trysendto,
1445 };
1446
1447 static void qcom_glink_rpdev_release(struct device *dev)
1448 {
1449         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1450
1451         kfree(rpdev);
1452 }
1453
1454 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1455                               char *name)
1456 {
1457         struct glink_channel *channel;
1458         struct rpmsg_device *rpdev;
1459         bool create_device = false;
1460         struct device_node *node;
1461         int lcid;
1462         int ret;
1463         unsigned long flags;
1464
1465         spin_lock_irqsave(&glink->idr_lock, flags);
1466         idr_for_each_entry(&glink->lcids, channel, lcid) {
1467                 if (!strcmp(channel->name, name))
1468                         break;
1469         }
1470         spin_unlock_irqrestore(&glink->idr_lock, flags);
1471
1472         if (!channel) {
1473                 channel = qcom_glink_alloc_channel(glink, name);
1474                 if (IS_ERR(channel))
1475                         return PTR_ERR(channel);
1476
1477                 /* The opening dance was initiated by the remote */
1478                 create_device = true;
1479         }
1480
1481         spin_lock_irqsave(&glink->idr_lock, flags);
1482         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1483         if (ret < 0) {
1484                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1485                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1486                 goto free_channel;
1487         }
1488         channel->rcid = ret;
1489         spin_unlock_irqrestore(&glink->idr_lock, flags);
1490
1491         complete_all(&channel->open_req);
1492
1493         if (create_device) {
1494                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1495                 if (!rpdev) {
1496                         ret = -ENOMEM;
1497                         goto rcid_remove;
1498                 }
1499
1500                 rpdev->ept = &channel->ept;
1501                 strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE);
1502                 rpdev->src = RPMSG_ADDR_ANY;
1503                 rpdev->dst = RPMSG_ADDR_ANY;
1504                 rpdev->ops = &glink_device_ops;
1505
1506                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1507                 rpdev->dev.of_node = node;
1508                 rpdev->dev.parent = glink->dev;
1509                 rpdev->dev.release = qcom_glink_rpdev_release;
1510
1511                 ret = rpmsg_register_device(rpdev);
1512                 if (ret)
1513                         goto rcid_remove;
1514
1515                 channel->rpdev = rpdev;
1516         }
1517
1518         return 0;
1519
1520 rcid_remove:
1521         spin_lock_irqsave(&glink->idr_lock, flags);
1522         idr_remove(&glink->rcids, channel->rcid);
1523         channel->rcid = 0;
1524         spin_unlock_irqrestore(&glink->idr_lock, flags);
1525 free_channel:
1526         /* Release the reference, iff we took it */
1527         if (create_device)
1528                 kref_put(&channel->refcount, qcom_glink_channel_release);
1529
1530         return ret;
1531 }
1532
1533 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1534 {
1535         struct rpmsg_channel_info chinfo;
1536         struct glink_channel *channel;
1537         unsigned long flags;
1538
1539         spin_lock_irqsave(&glink->idr_lock, flags);
1540         channel = idr_find(&glink->rcids, rcid);
1541         spin_unlock_irqrestore(&glink->idr_lock, flags);
1542         if (WARN(!channel, "close request on unknown channel\n"))
1543                 return;
1544
1545         /* cancel pending rx_done work */
1546         cancel_work_sync(&channel->intent_work);
1547
1548         if (channel->rpdev) {
1549                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1550                 chinfo.src = RPMSG_ADDR_ANY;
1551                 chinfo.dst = RPMSG_ADDR_ANY;
1552
1553                 rpmsg_unregister_device(glink->dev, &chinfo);
1554         }
1555         channel->rpdev = NULL;
1556
1557         qcom_glink_send_close_ack(glink, channel->rcid);
1558
1559         spin_lock_irqsave(&glink->idr_lock, flags);
1560         idr_remove(&glink->rcids, channel->rcid);
1561         channel->rcid = 0;
1562         spin_unlock_irqrestore(&glink->idr_lock, flags);
1563
1564         kref_put(&channel->refcount, qcom_glink_channel_release);
1565 }
1566
1567 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1568 {
1569         struct rpmsg_channel_info chinfo;
1570         struct glink_channel *channel;
1571         unsigned long flags;
1572
1573         /* To wakeup any blocking writers */
1574         wake_up_all(&glink->tx_avail_notify);
1575
1576         spin_lock_irqsave(&glink->idr_lock, flags);
1577         channel = idr_find(&glink->lcids, lcid);
1578         if (WARN(!channel, "close ack on unknown channel\n")) {
1579                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1580                 return;
1581         }
1582
1583         idr_remove(&glink->lcids, channel->lcid);
1584         channel->lcid = 0;
1585         spin_unlock_irqrestore(&glink->idr_lock, flags);
1586
1587         /* Decouple the potential rpdev from the channel */
1588         if (channel->rpdev) {
1589                 strscpy(chinfo.name, channel->name, sizeof(chinfo.name));
1590                 chinfo.src = RPMSG_ADDR_ANY;
1591                 chinfo.dst = RPMSG_ADDR_ANY;
1592
1593                 rpmsg_unregister_device(glink->dev, &chinfo);
1594         }
1595         channel->rpdev = NULL;
1596
1597         kref_put(&channel->refcount, qcom_glink_channel_release);
1598 }
1599
1600 static void qcom_glink_work(struct work_struct *work)
1601 {
1602         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1603                                                 rx_work);
1604         struct glink_defer_cmd *dcmd;
1605         struct glink_msg *msg;
1606         unsigned long flags;
1607         unsigned int param1;
1608         unsigned int param2;
1609         unsigned int cmd;
1610
1611         for (;;) {
1612                 spin_lock_irqsave(&glink->rx_lock, flags);
1613                 if (list_empty(&glink->rx_queue)) {
1614                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1615                         break;
1616                 }
1617                 dcmd = list_first_entry(&glink->rx_queue,
1618                                         struct glink_defer_cmd, node);
1619                 list_del(&dcmd->node);
1620                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1621
1622                 msg = &dcmd->msg;
1623                 cmd = le16_to_cpu(msg->cmd);
1624                 param1 = le16_to_cpu(msg->param1);
1625                 param2 = le32_to_cpu(msg->param2);
1626
1627                 switch (cmd) {
1628                 case RPM_CMD_VERSION:
1629                         qcom_glink_receive_version(glink, param1, param2);
1630                         break;
1631                 case RPM_CMD_VERSION_ACK:
1632                         qcom_glink_receive_version_ack(glink, param1, param2);
1633                         break;
1634                 case RPM_CMD_OPEN:
1635                         qcom_glink_rx_open(glink, param1, msg->data);
1636                         break;
1637                 case RPM_CMD_CLOSE:
1638                         qcom_glink_rx_close(glink, param1);
1639                         break;
1640                 case RPM_CMD_CLOSE_ACK:
1641                         qcom_glink_rx_close_ack(glink, param1);
1642                         break;
1643                 case RPM_CMD_RX_INTENT_REQ:
1644                         qcom_glink_handle_intent_req(glink, param1, param2);
1645                         break;
1646                 default:
1647                         WARN(1, "Unknown defer object %d\n", cmd);
1648                         break;
1649                 }
1650
1651                 kfree(dcmd);
1652         }
1653 }
1654
1655 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1656 {
1657         struct glink_defer_cmd *dcmd;
1658         struct glink_defer_cmd *tmp;
1659
1660         /* cancel any pending deferred rx_work */
1661         cancel_work_sync(&glink->rx_work);
1662
1663         list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1664                 kfree(dcmd);
1665 }
1666
1667 static ssize_t rpmsg_name_show(struct device *dev,
1668                                struct device_attribute *attr, char *buf)
1669 {
1670         int ret = 0;
1671         const char *name;
1672
1673         ret = of_property_read_string(dev->of_node, "label", &name);
1674         if (ret < 0)
1675                 name = dev->of_node->name;
1676
1677         return snprintf(buf, RPMSG_NAME_SIZE, "%s\n", name);
1678 }
1679 static DEVICE_ATTR_RO(rpmsg_name);
1680
1681 static struct attribute *qcom_glink_attrs[] = {
1682         &dev_attr_rpmsg_name.attr,
1683         NULL
1684 };
1685 ATTRIBUTE_GROUPS(qcom_glink);
1686
1687 static void qcom_glink_device_release(struct device *dev)
1688 {
1689         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1690         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1691
1692         /* Release qcom_glink_alloc_channel() reference */
1693         kref_put(&channel->refcount, qcom_glink_channel_release);
1694         kfree(rpdev);
1695 }
1696
1697 static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1698 {
1699         struct rpmsg_device *rpdev;
1700         struct glink_channel *channel;
1701
1702         rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1703         if (!rpdev)
1704                 return -ENOMEM;
1705
1706         channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1707         if (IS_ERR(channel)) {
1708                 kfree(rpdev);
1709                 return PTR_ERR(channel);
1710         }
1711         channel->rpdev = rpdev;
1712
1713         rpdev->ept = &channel->ept;
1714         rpdev->ops = &glink_device_ops;
1715         rpdev->dev.parent = glink->dev;
1716         rpdev->dev.release = qcom_glink_device_release;
1717
1718         return rpmsg_ctrldev_register_device(rpdev);
1719 }
1720
1721 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1722                                            unsigned long features,
1723                                            struct qcom_glink_pipe *rx,
1724                                            struct qcom_glink_pipe *tx,
1725                                            bool intentless)
1726 {
1727         int irq;
1728         int ret;
1729         struct qcom_glink *glink;
1730
1731         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1732         if (!glink)
1733                 return ERR_PTR(-ENOMEM);
1734
1735         glink->dev = dev;
1736         glink->tx_pipe = tx;
1737         glink->rx_pipe = rx;
1738
1739         glink->features = features;
1740         glink->intentless = intentless;
1741
1742         spin_lock_init(&glink->tx_lock);
1743         spin_lock_init(&glink->rx_lock);
1744         INIT_LIST_HEAD(&glink->rx_queue);
1745         INIT_WORK(&glink->rx_work, qcom_glink_work);
1746         init_waitqueue_head(&glink->tx_avail_notify);
1747
1748         spin_lock_init(&glink->idr_lock);
1749         idr_init(&glink->lcids);
1750         idr_init(&glink->rcids);
1751
1752         glink->dev->groups = qcom_glink_groups;
1753
1754         ret = device_add_groups(dev, qcom_glink_groups);
1755         if (ret)
1756                 dev_err(dev, "failed to add groups\n");
1757
1758         ret = of_property_read_string(dev->of_node, "label", &glink->name);
1759         if (ret < 0)
1760                 glink->name = dev->of_node->name;
1761
1762         glink->mbox_client.dev = dev;
1763         glink->mbox_client.knows_txdone = true;
1764         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1765         if (IS_ERR(glink->mbox_chan)) {
1766                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1767                         dev_err(dev, "failed to acquire IPC channel\n");
1768                 return ERR_CAST(glink->mbox_chan);
1769         }
1770
1771         irq = of_irq_get(dev->of_node, 0);
1772         ret = devm_request_irq(dev, irq,
1773                                qcom_glink_native_intr,
1774                                IRQF_NO_SUSPEND | IRQF_SHARED,
1775                                "glink-native", glink);
1776         if (ret) {
1777                 dev_err(dev, "failed to request IRQ\n");
1778                 return ERR_PTR(ret);
1779         }
1780
1781         glink->irq = irq;
1782
1783         ret = qcom_glink_send_version(glink);
1784         if (ret)
1785                 return ERR_PTR(ret);
1786
1787         ret = qcom_glink_create_chrdev(glink);
1788         if (ret)
1789                 dev_err(glink->dev, "failed to register chrdev\n");
1790
1791         return glink;
1792 }
1793 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1794
1795 static int qcom_glink_remove_device(struct device *dev, void *data)
1796 {
1797         device_unregister(dev);
1798
1799         return 0;
1800 }
1801
1802 void qcom_glink_native_remove(struct qcom_glink *glink)
1803 {
1804         struct glink_channel *channel;
1805         int cid;
1806         int ret;
1807
1808         disable_irq(glink->irq);
1809         qcom_glink_cancel_rx_work(glink);
1810
1811         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1812         if (ret)
1813                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1814
1815         /* Release any defunct local channels, waiting for close-ack */
1816         idr_for_each_entry(&glink->lcids, channel, cid)
1817                 kref_put(&channel->refcount, qcom_glink_channel_release);
1818
1819         /* Release any defunct local channels, waiting for close-req */
1820         idr_for_each_entry(&glink->rcids, channel, cid)
1821                 kref_put(&channel->refcount, qcom_glink_channel_release);
1822
1823         idr_destroy(&glink->lcids);
1824         idr_destroy(&glink->rcids);
1825         mbox_free_channel(glink->mbox_chan);
1826 }
1827 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1828
1829 void qcom_glink_native_unregister(struct qcom_glink *glink)
1830 {
1831         device_unregister(glink->dev);
1832 }
1833 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1834
1835 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1836 MODULE_LICENSE("GPL v2");