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/platform_device.h>
  15 #include <linux/regmap.h>
  16 #include <linux/rpmsg.h>
  17 #include <linux/sizes.h>
  18 #include <linux/slab.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/mailbox_client.h>
  21
  22 #include "rpmsg_internal.h"
  23 #include "qcom_glink_native.h"
  24
  25 #define GLINK_NAME_SIZE         32
  26 #define GLINK_VERSION_1         1
  27
  28 #define RPM_GLINK_CID_MIN       1
  29 #define RPM_GLINK_CID_MAX       65536
  30
  31 struct glink_msg {
  32         __le16 cmd;
  33         __le16 param1;
  34         __le32 param2;
  35         u8 data[];
  36 } __packed;
  37
  38 /**
  39  * struct glink_defer_cmd - deferred incoming control message
  40  * @node:       list node
  41  * @msg:        message header
  42  * @data:       payload of the message
  43  *
  44  * Copy of a received control message, to be added to @rx_queue and processed
  45  * by @rx_work of @qcom_glink.
  46  */
  47 struct glink_defer_cmd {
  48         struct list_head node;
  49
  50         struct glink_msg msg;
  51         u8 data[];
  52 };
  53
  54 /**
  55  * struct glink_core_rx_intent - RX intent
  56  * RX intent
  57  *
  58  * @data: pointer to the data (may be NULL for zero-copy)
  59  * @id: remote or local intent ID
  60  * @size: size of the original intent (do not modify)
  61  * @reuse: To mark if the intent can be reused after first use
  62  * @in_use: To mark if intent is already in use for the channel
  63  * @offset: next write offset (initially 0)
  64  * @node:       list node
  65  */
  66 struct glink_core_rx_intent {
  67         void *data;
  68         u32 id;
  69         size_t size;
  70         bool reuse;
  71         bool in_use;
  72         u32 offset;
  73
  74         struct list_head node;
  75 };
  76
  77 /**
  78  * struct qcom_glink - driver context, relates to one remote subsystem
  79  * @dev:        reference to the associated struct device
  80  * @rx_pipe:    pipe object for receive FIFO
  81  * @tx_pipe:    pipe object for transmit FIFO
  82  * @rx_work:    worker for handling received control messages
  83  * @rx_lock:    protects the @rx_queue
  84  * @rx_queue:   queue of received control messages to be processed in @rx_work
  85  * @tx_lock:    synchronizes operations on the tx fifo
  86  * @idr_lock:   synchronizes @lcids and @rcids modifications
  87  * @lcids:      idr of all channels with a known local channel id
  88  * @rcids:      idr of all channels with a known remote channel id
  89  * @features:   remote features
  90  * @intentless: flag to indicate that there is no intent
  91  * @tx_avail_notify: Waitqueue for pending tx tasks
  92  * @sent_read_notify: flag to check cmd sent or not
  93  * @abort_tx:   flag indicating that all tx attempts should fail
  94  */
  95 struct qcom_glink {
  96         struct device *dev;
  97
  98         struct qcom_glink_pipe *rx_pipe;
  99         struct qcom_glink_pipe *tx_pipe;
 100
 101         struct work_struct rx_work;
 102         spinlock_t rx_lock;
 103         struct list_head rx_queue;
 104
 105         spinlock_t tx_lock;
 106
 107         spinlock_t idr_lock;
 108         struct idr lcids;
 109         struct idr rcids;
 110         unsigned long features;
 111
 112         bool intentless;
 113         wait_queue_head_t tx_avail_notify;
 114         bool sent_read_notify;
 115
 116         bool abort_tx;
 117 };
 118
 119 enum {
 120         GLINK_STATE_CLOSED,
 121         GLINK_STATE_OPENING,
 122         GLINK_STATE_OPEN,
 123         GLINK_STATE_CLOSING,
 124 };
 125
 126 /**
 127  * struct glink_channel - internal representation of a channel
 128  * @rpdev:      rpdev reference, only used for primary endpoints
 129  * @ept:        rpmsg endpoint this channel is associated with
 130  * @glink:      qcom_glink context handle
 131  * @refcount:   refcount for the channel object
 132  * @recv_lock:  guard for @ept.cb
 133  * @name:       unique channel name/identifier
 134  * @lcid:       channel id, in local space
 135  * @rcid:       channel id, in remote space
 136  * @intent_lock: lock for protection of @liids, @riids
 137  * @liids:      idr of all local intents
 138  * @riids:      idr of all remote intents
 139  * @intent_work: worker responsible for transmitting rx_done packets
 140  * @done_intents: list of intents that needs to be announced rx_done
 141  * @buf:        receive buffer, for gathering fragments
 142  * @buf_offset: write offset in @buf
 143  * @buf_size:   size of current @buf
 144  * @open_ack:   completed once remote has acked the open-request
 145  * @open_req:   completed once open-request has been received
 146  * @intent_req_lock: Synchronises multiple intent requests
 147  * @intent_req_result: Result of intent request
 148  * @intent_req_comp: Completion for intent_req signalling
 149  */
 150 struct glink_channel {
 151         struct rpmsg_endpoint ept;
 152
 153         struct rpmsg_device *rpdev;
 154         struct qcom_glink *glink;
 155
 156         struct kref refcount;
 157
 158         spinlock_t recv_lock;
 159
 160         char *name;
 161         unsigned int lcid;
 162         unsigned int rcid;
 163
 164         spinlock_t intent_lock;
 165         struct idr liids;
 166         struct idr riids;
 167         struct work_struct intent_work;
 168         struct list_head done_intents;
 169
 170         struct glink_core_rx_intent *buf;
 171         int buf_offset;
 172         int buf_size;
 173
 174         struct completion open_ack;
 175         struct completion open_req;
 176
 177         struct mutex intent_req_lock;
 178         bool intent_req_result;
 179         struct completion intent_req_comp;
 180 };
 181
 182 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 183
 184 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 185
 186 #define GLINK_CMD_VERSION               0
 187 #define GLINK_CMD_VERSION_ACK           1
 188 #define GLINK_CMD_OPEN                  2
 189 #define GLINK_CMD_CLOSE                 3
 190 #define GLINK_CMD_OPEN_ACK              4
 191 #define GLINK_CMD_INTENT                5
 192 #define GLINK_CMD_RX_DONE               6
 193 #define GLINK_CMD_RX_INTENT_REQ         7
 194 #define GLINK_CMD_RX_INTENT_REQ_ACK     8
 195 #define GLINK_CMD_TX_DATA               9
 196 #define GLINK_CMD_CLOSE_ACK             11
 197 #define GLINK_CMD_TX_DATA_CONT          12
 198 #define GLINK_CMD_READ_NOTIF            13
 199 #define GLINK_CMD_RX_DONE_W_REUSE       14
 200
 201 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 202
 203 static void qcom_glink_rx_done_work(struct work_struct *work);
 204
 205 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 206                                                       const char *name)
 207 {
 208         struct glink_channel *channel;
 209
 210         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 211         if (!channel)
 212                 return ERR_PTR(-ENOMEM);
 213
 214         /* Setup glink internal glink_channel data */
 215         spin_lock_init(&channel->recv_lock);
 216         spin_lock_init(&channel->intent_lock);
 217         mutex_init(&channel->intent_req_lock);
 218
 219         channel->glink = glink;
 220         channel->name = kstrdup(name, GFP_KERNEL);
 221
 222         init_completion(&channel->open_req);
 223         init_completion(&channel->open_ack);
 224         init_completion(&channel->intent_req_comp);
 225
 226         INIT_LIST_HEAD(&channel->done_intents);
 227         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 228
 229         idr_init(&channel->liids);
 230         idr_init(&channel->riids);
 231         kref_init(&channel->refcount);
 232
 233         return channel;
 234 }
 235
 236 static void qcom_glink_channel_release(struct kref *ref)
 237 {
 238         struct glink_channel *channel = container_of(ref, struct glink_channel,
 239                                                      refcount);
 240         struct glink_core_rx_intent *intent;
 241         struct glink_core_rx_intent *tmp;
 242         unsigned long flags;
 243         int iid;
 244
 245         /* cancel pending rx_done work */
 246         cancel_work_sync(&channel->intent_work);
 247
 248         spin_lock_irqsave(&channel->intent_lock, flags);
 249         /* Free all non-reuse intents pending rx_done work */
 250         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 251                 if (!intent->reuse) {
 252                         kfree(intent->data);
 253                         kfree(intent);
 254                 }
 255         }
 256
 257         idr_for_each_entry(&channel->liids, tmp, iid) {
 258                 kfree(tmp->data);
 259                 kfree(tmp);
 260         }
 261         idr_destroy(&channel->liids);
 262
 263         idr_for_each_entry(&channel->riids, tmp, iid)
 264                 kfree(tmp);
 265         idr_destroy(&channel->riids);
 266         spin_unlock_irqrestore(&channel->intent_lock, flags);
 267
 268         kfree(channel->name);
 269         kfree(channel);
 270 }
 271
 272 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 273 {
 274         return glink->rx_pipe->avail(glink->rx_pipe);
 275 }
 276
 277 static void qcom_glink_rx_peek(struct qcom_glink *glink,
 278                                void *data, unsigned int offset, size_t count)
 279 {
 280         glink->rx_pipe->peek(glink->rx_pipe, data, offset, count);
 281 }
 282
 283 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 284 {
 285         glink->rx_pipe->advance(glink->rx_pipe, count);
 286 }
 287
 288 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 289 {
 290         return glink->tx_pipe->avail(glink->tx_pipe);
 291 }
 292
 293 static void qcom_glink_tx_write(struct qcom_glink *glink,
 294                                 const void *hdr, size_t hlen,
 295                                 const void *data, size_t dlen)
 296 {
 297         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 298 }
 299
 300 static void qcom_glink_tx_kick(struct qcom_glink *glink)
 301 {
 302         glink->tx_pipe->kick(glink->tx_pipe);
 303 }
 304
 305 static void qcom_glink_send_read_notify(struct qcom_glink *glink)
 306 {
 307         struct glink_msg msg;
 308
 309         msg.cmd = cpu_to_le16(GLINK_CMD_READ_NOTIF);
 310         msg.param1 = 0;
 311         msg.param2 = 0;
 312
 313         qcom_glink_tx_write(glink, &msg, sizeof(msg), NULL, 0);
 314
 315         qcom_glink_tx_kick(glink);
 316 }
 317
 318 static int qcom_glink_tx(struct qcom_glink *glink,
 319                          const void *hdr, size_t hlen,
 320                          const void *data, size_t dlen, bool wait)
 321 {
 322         unsigned int tlen = hlen + dlen;
 323         unsigned long flags;
 324         int ret = 0;
 325
 326         /* Reject packets that are too big */
 327         if (tlen >= glink->tx_pipe->length)
 328                 return -EINVAL;
 329
 330         spin_lock_irqsave(&glink->tx_lock, flags);
 331
 332         if (glink->abort_tx) {
 333                 ret = -EIO;
 334                 goto out;
 335         }
 336
 337         while (qcom_glink_tx_avail(glink) < tlen) {
 338                 if (!wait) {
 339                         ret = -EAGAIN;
 340                         goto out;
 341                 }
 342
 343                 if (glink->abort_tx) {
 344                         ret = -EIO;
 345                         goto out;
 346                 }
 347
 348                 if (!glink->sent_read_notify) {
 349                         glink->sent_read_notify = true;
 350                         qcom_glink_send_read_notify(glink);
 351                 }
 352
 353                 /* Wait without holding the tx_lock */
 354                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 355
 356                 wait_event_timeout(glink->tx_avail_notify,
 357                                    qcom_glink_tx_avail(glink) >= tlen, 10 * HZ);
 358
 359                 spin_lock_irqsave(&glink->tx_lock, flags);
 360
 361                 if (qcom_glink_tx_avail(glink) >= tlen)
 362                         glink->sent_read_notify = false;
 363         }
 364
 365         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 366         qcom_glink_tx_kick(glink);
 367
 368 out:
 369         spin_unlock_irqrestore(&glink->tx_lock, flags);
 370
 371         return ret;
 372 }
 373
 374 static int qcom_glink_send_version(struct qcom_glink *glink)
 375 {
 376         struct glink_msg msg;
 377
 378         msg.cmd = cpu_to_le16(GLINK_CMD_VERSION);
 379         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 380         msg.param2 = cpu_to_le32(glink->features);
 381
 382         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 383 }
 384
 385 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 386 {
 387         struct glink_msg msg;
 388
 389         msg.cmd = cpu_to_le16(GLINK_CMD_VERSION_ACK);
 390         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 391         msg.param2 = cpu_to_le32(glink->features);
 392
 393         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 394 }
 395
 396 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 397                                      struct glink_channel *channel)
 398 {
 399         struct glink_msg msg;
 400
 401         msg.cmd = cpu_to_le16(GLINK_CMD_OPEN_ACK);
 402         msg.param1 = cpu_to_le16(channel->rcid);
 403         msg.param2 = cpu_to_le32(0);
 404
 405         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 406 }
 407
 408 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 409                                              unsigned int cid, bool granted)
 410 {
 411         struct glink_channel *channel;
 412         unsigned long flags;
 413
 414         spin_lock_irqsave(&glink->idr_lock, flags);
 415         channel = idr_find(&glink->rcids, cid);
 416         spin_unlock_irqrestore(&glink->idr_lock, flags);
 417         if (!channel) {
 418                 dev_err(glink->dev, "unable to find channel\n");
 419                 return;
 420         }
 421
 422         channel->intent_req_result = granted;
 423         complete(&channel->intent_req_comp);
 424 }
 425
 426 static void qcom_glink_intent_req_abort(struct glink_channel *channel)
 427 {
 428         channel->intent_req_result = 0;
 429         complete(&channel->intent_req_comp);
 430 }
 431
 432 /**
 433  * qcom_glink_send_open_req() - send a GLINK_CMD_OPEN request to the remote
 434  * @glink: Ptr to the glink edge
 435  * @channel: Ptr to the channel that the open req is sent
 436  *
 437  * Allocates a local channel id and sends a GLINK_CMD_OPEN message to the remote.
 438  * Will return with refcount held, regardless of outcome.
 439  *
 440  * Return: 0 on success, negative errno otherwise.
 441  */
 442 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 443                                     struct glink_channel *channel)
 444 {
 445         struct {
 446                 struct glink_msg msg;
 447                 u8 name[GLINK_NAME_SIZE];
 448         } __packed req;
 449         int name_len = strlen(channel->name) + 1;
 450         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 451         int ret;
 452         unsigned long flags;
 453
 454         kref_get(&channel->refcount);
 455
 456         spin_lock_irqsave(&glink->idr_lock, flags);
 457         ret = idr_alloc_cyclic(&glink->lcids, channel,
 458                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 459                                GFP_ATOMIC);
 460         spin_unlock_irqrestore(&glink->idr_lock, flags);
 461         if (ret < 0)
 462                 return ret;
 463
 464         channel->lcid = ret;
 465
 466         req.msg.cmd = cpu_to_le16(GLINK_CMD_OPEN);
 467         req.msg.param1 = cpu_to_le16(channel->lcid);
 468         req.msg.param2 = cpu_to_le32(name_len);
 469         strcpy(req.name, channel->name);
 470
 471         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 472         if (ret)
 473                 goto remove_idr;
 474
 475         return 0;
 476
 477 remove_idr:
 478         spin_lock_irqsave(&glink->idr_lock, flags);
 479         idr_remove(&glink->lcids, channel->lcid);
 480         channel->lcid = 0;
 481         spin_unlock_irqrestore(&glink->idr_lock, flags);
 482
 483         return ret;
 484 }
 485
 486 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 487                                       struct glink_channel *channel)
 488 {
 489         struct glink_msg req;
 490
 491         req.cmd = cpu_to_le16(GLINK_CMD_CLOSE);
 492         req.param1 = cpu_to_le16(channel->lcid);
 493         req.param2 = 0;
 494
 495         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 496 }
 497
 498 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 499                                       unsigned int rcid)
 500 {
 501         struct glink_msg req;
 502
 503         req.cmd = cpu_to_le16(GLINK_CMD_CLOSE_ACK);
 504         req.param1 = cpu_to_le16(rcid);
 505         req.param2 = 0;
 506
 507         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 508 }
 509
 510 static void qcom_glink_rx_done_work(struct work_struct *work)
 511 {
 512         struct glink_channel *channel = container_of(work, struct glink_channel,
 513                                                      intent_work);
 514         struct qcom_glink *glink = channel->glink;
 515         struct glink_core_rx_intent *intent, *tmp;
 516         struct {
 517                 u16 id;
 518                 u16 lcid;
 519                 u32 liid;
 520         } __packed cmd;
 521
 522         unsigned int cid = channel->lcid;
 523         unsigned int iid;
 524         bool reuse;
 525         unsigned long flags;
 526
 527         spin_lock_irqsave(&channel->intent_lock, flags);
 528         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 529                 list_del(&intent->node);
 530                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 531                 iid = intent->id;
 532                 reuse = intent->reuse;
 533
 534                 cmd.id = reuse ? GLINK_CMD_RX_DONE_W_REUSE : GLINK_CMD_RX_DONE;
 535                 cmd.lcid = cid;
 536                 cmd.liid = iid;
 537
 538                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 539                 if (!reuse) {
 540                         kfree(intent->data);
 541                         kfree(intent);
 542                 }
 543                 spin_lock_irqsave(&channel->intent_lock, flags);
 544         }
 545         spin_unlock_irqrestore(&channel->intent_lock, flags);
 546 }
 547
 548 static void qcom_glink_rx_done(struct qcom_glink *glink,
 549                                struct glink_channel *channel,
 550                                struct glink_core_rx_intent *intent)
 551 {
 552         /* We don't send RX_DONE to intentless systems */
 553         if (glink->intentless) {
 554                 kfree(intent->data);
 555                 kfree(intent);
 556                 return;
 557         }
 558
 559         /* Take it off the tree of receive intents */
 560         if (!intent->reuse) {
 561                 spin_lock(&channel->intent_lock);
 562                 idr_remove(&channel->liids, intent->id);
 563                 spin_unlock(&channel->intent_lock);
 564         }
 565
 566         /* Schedule the sending of a rx_done indication */
 567         spin_lock(&channel->intent_lock);
 568         list_add_tail(&intent->node, &channel->done_intents);
 569         spin_unlock(&channel->intent_lock);
 570
 571         schedule_work(&channel->intent_work);
 572 }
 573
 574 /**
 575  * qcom_glink_receive_version() - receive version/features from remote system
 576  *
 577  * @glink:      pointer to transport interface
 578  * @version:    remote version
 579  * @features:   remote features
 580  *
 581  * This function is called in response to a remote-initiated version/feature
 582  * negotiation sequence.
 583  */
 584 static void qcom_glink_receive_version(struct qcom_glink *glink,
 585                                        u32 version,
 586                                        u32 features)
 587 {
 588         switch (version) {
 589         case 0:
 590                 break;
 591         case GLINK_VERSION_1:
 592                 glink->features &= features;
 593                 fallthrough;
 594         default:
 595                 qcom_glink_send_version_ack(glink);
 596                 break;
 597         }
 598 }
 599
 600 /**
 601  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 602  *
 603  * @glink:      pointer to transport interface
 604  * @version:    remote version response
 605  * @features:   remote features response
 606  *
 607  * This function is called in response to a local-initiated version/feature
 608  * negotiation sequence and is the counter-offer from the remote side based
 609  * upon the initial version and feature set requested.
 610  */
 611 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 612                                            u32 version,
 613                                            u32 features)
 614 {
 615         switch (version) {
 616         case 0:
 617                 /* Version negotiation failed */
 618                 break;
 619         case GLINK_VERSION_1:
 620                 if (features == glink->features)
 621                         break;
 622
 623                 glink->features &= features;
 624                 fallthrough;
 625         default:
 626                 qcom_glink_send_version(glink);
 627                 break;
 628         }
 629 }
 630
 631 /**
 632  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 633  *      wire format and transmit
 634  * @glink:      The transport to transmit on.
 635  * @channel:    The glink channel
 636  * @granted:    The request response to encode.
 637  *
 638  * Return: 0 on success or standard Linux error code.
 639  */
 640 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 641                                           struct glink_channel *channel,
 642                                           bool granted)
 643 {
 644         struct glink_msg msg;
 645
 646         msg.cmd = cpu_to_le16(GLINK_CMD_RX_INTENT_REQ_ACK);
 647         msg.param1 = cpu_to_le16(channel->lcid);
 648         msg.param2 = cpu_to_le32(granted);
 649
 650         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 651
 652         return 0;
 653 }
 654
 655 /**
 656  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 657  *                         transmit
 658  * @glink:      The transport to transmit on.
 659  * @channel:    The local channel
 660  * @intent:     The intent to pass on to remote.
 661  *
 662  * Return: 0 on success or standard Linux error code.
 663  */
 664 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 665                                        struct glink_channel *channel,
 666                                        struct glink_core_rx_intent *intent)
 667 {
 668         struct command {
 669                 __le16 id;
 670                 __le16 lcid;
 671                 __le32 count;
 672                 __le32 size;
 673                 __le32 liid;
 674         } __packed;
 675         struct command cmd;
 676
 677         cmd.id = cpu_to_le16(GLINK_CMD_INTENT);
 678         cmd.lcid = cpu_to_le16(channel->lcid);
 679         cmd.count = cpu_to_le32(1);
 680         cmd.size = cpu_to_le32(intent->size);
 681         cmd.liid = cpu_to_le32(intent->id);
 682
 683         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 684
 685         return 0;
 686 }
 687
 688 static struct glink_core_rx_intent *
 689 qcom_glink_alloc_intent(struct qcom_glink *glink,
 690                         struct glink_channel *channel,
 691                         size_t size,
 692                         bool reuseable)
 693 {
 694         struct glink_core_rx_intent *intent;
 695         int ret;
 696         unsigned long flags;
 697
 698         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 699         if (!intent)
 700                 return NULL;
 701
 702         intent->data = kzalloc(size, GFP_KERNEL);
 703         if (!intent->data)
 704                 goto free_intent;
 705
 706         spin_lock_irqsave(&channel->intent_lock, flags);
 707         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 708         if (ret < 0) {
 709                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 710                 goto free_data;
 711         }
 712         spin_unlock_irqrestore(&channel->intent_lock, flags);
 713
 714         intent->id = ret;
 715         intent->size = size;
 716         intent->reuse = reuseable;
 717
 718         return intent;
 719
 720 free_data:
 721         kfree(intent->data);
 722 free_intent:
 723         kfree(intent);
 724         return NULL;
 725 }
 726
 727 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 728                                       u32 cid, uint32_t iid,
 729                                       bool reuse)
 730 {
 731         struct glink_core_rx_intent *intent;
 732         struct glink_channel *channel;
 733         unsigned long flags;
 734
 735         spin_lock_irqsave(&glink->idr_lock, flags);
 736         channel = idr_find(&glink->rcids, cid);
 737         spin_unlock_irqrestore(&glink->idr_lock, flags);
 738         if (!channel) {
 739                 dev_err(glink->dev, "invalid channel id received\n");
 740                 return;
 741         }
 742
 743         spin_lock_irqsave(&channel->intent_lock, flags);
 744         intent = idr_find(&channel->riids, iid);
 745
 746         if (!intent) {
 747                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 748                 dev_err(glink->dev, "invalid intent id received\n");
 749                 return;
 750         }
 751
 752         intent->in_use = false;
 753
 754         if (!reuse) {
 755                 idr_remove(&channel->riids, intent->id);
 756                 kfree(intent);
 757         }
 758         spin_unlock_irqrestore(&channel->intent_lock, flags);
 759 }
 760
 761 /**
 762  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 763  *                                          from remote side
 764  * @glink:      Pointer to the transport interface
 765  * @cid:        Remote channel ID
 766  * @size:       size of the intent
 767  *
 768  * The function searches for the local channel to which the request for
 769  * rx_intent has arrived and allocates and notifies the remote back
 770  */
 771 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 772                                          u32 cid, size_t size)
 773 {
 774         struct glink_core_rx_intent *intent;
 775         struct glink_channel *channel;
 776         unsigned long flags;
 777
 778         spin_lock_irqsave(&glink->idr_lock, flags);
 779         channel = idr_find(&glink->rcids, cid);
 780         spin_unlock_irqrestore(&glink->idr_lock, flags);
 781
 782         if (!channel) {
 783                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 784                 return;
 785         }
 786
 787         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 788         if (intent)
 789                 qcom_glink_advertise_intent(glink, channel, intent);
 790
 791         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 792 }
 793
 794 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 795 {
 796         struct glink_defer_cmd *dcmd;
 797
 798         extra = ALIGN(extra, 8);
 799
 800         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 801                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 802                 return -ENXIO;
 803         }
 804
 805         dcmd = kzalloc(struct_size(dcmd, data, extra), GFP_ATOMIC);
 806         if (!dcmd)
 807                 return -ENOMEM;
 808
 809         INIT_LIST_HEAD(&dcmd->node);
 810
 811         qcom_glink_rx_peek(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 812
 813         spin_lock(&glink->rx_lock);
 814         list_add_tail(&dcmd->node, &glink->rx_queue);
 815         spin_unlock(&glink->rx_lock);
 816
 817         schedule_work(&glink->rx_work);
 818         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 819
 820         return 0;
 821 }
 822
 823 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 824 {
 825         struct glink_core_rx_intent *intent;
 826         struct glink_channel *channel;
 827         struct {
 828                 struct glink_msg msg;
 829                 __le32 chunk_size;
 830                 __le32 left_size;
 831         } __packed hdr;
 832         unsigned int chunk_size;
 833         unsigned int left_size;
 834         unsigned int rcid;
 835         unsigned int liid;
 836         int ret = 0;
 837         unsigned long flags;
 838
 839         if (avail < sizeof(hdr)) {
 840                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 841                 return -EAGAIN;
 842         }
 843
 844         qcom_glink_rx_peek(glink, &hdr, 0, sizeof(hdr));
 845         chunk_size = le32_to_cpu(hdr.chunk_size);
 846         left_size = le32_to_cpu(hdr.left_size);
 847
 848         if (avail < sizeof(hdr) + chunk_size) {
 849                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 850                 return -EAGAIN;
 851         }
 852
 853         rcid = le16_to_cpu(hdr.msg.param1);
 854         spin_lock_irqsave(&glink->idr_lock, flags);
 855         channel = idr_find(&glink->rcids, rcid);
 856         spin_unlock_irqrestore(&glink->idr_lock, flags);
 857         if (!channel) {
 858                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 859
 860                 /* Drop the message */
 861                 goto advance_rx;
 862         }
 863
 864         if (glink->intentless) {
 865                 /* Might have an ongoing, fragmented, message to append */
 866                 if (!channel->buf) {
 867                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 868                         if (!intent)
 869                                 return -ENOMEM;
 870
 871                         intent->data = kmalloc(chunk_size + left_size,
 872                                                GFP_ATOMIC);
 873                         if (!intent->data) {
 874                                 kfree(intent);
 875                                 return -ENOMEM;
 876                         }
 877
 878                         intent->id = 0xbabababa;
 879                         intent->size = chunk_size + left_size;
 880                         intent->offset = 0;
 881
 882                         channel->buf = intent;
 883                 } else {
 884                         intent = channel->buf;
 885                 }
 886         } else {
 887                 liid = le32_to_cpu(hdr.msg.param2);
 888
 889                 spin_lock_irqsave(&channel->intent_lock, flags);
 890                 intent = idr_find(&channel->liids, liid);
 891                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 892
 893                 if (!intent) {
 894                         dev_err(glink->dev,
 895                                 "no intent found for channel %s intent %d",
 896                                 channel->name, liid);
 897                         ret = -ENOENT;
 898                         goto advance_rx;
 899                 }
 900         }
 901
 902         if (intent->size - intent->offset < chunk_size) {
 903                 dev_err(glink->dev, "Insufficient space in intent\n");
 904
 905                 /* The packet header lied, drop payload */
 906                 goto advance_rx;
 907         }
 908
 909         qcom_glink_rx_peek(glink, intent->data + intent->offset,
 910                            sizeof(hdr), chunk_size);
 911         intent->offset += chunk_size;
 912
 913         /* Handle message when no fragments remain to be received */
 914         if (!left_size) {
 915                 spin_lock(&channel->recv_lock);
 916                 if (channel->ept.cb) {
 917                         channel->ept.cb(channel->ept.rpdev,
 918                                         intent->data,
 919                                         intent->offset,
 920                                         channel->ept.priv,
 921                                         RPMSG_ADDR_ANY);
 922                 }
 923                 spin_unlock(&channel->recv_lock);
 924
 925                 intent->offset = 0;
 926                 channel->buf = NULL;
 927
 928                 qcom_glink_rx_done(glink, channel, intent);
 929         }
 930
 931 advance_rx:
 932         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 933
 934         return ret;
 935 }
 936
 937 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 938                                      unsigned int cid,
 939                                      unsigned int count,
 940                                      size_t avail)
 941 {
 942         struct glink_core_rx_intent *intent;
 943         struct glink_channel *channel;
 944         struct intent_pair {
 945                 __le32 size;
 946                 __le32 iid;
 947         };
 948
 949         struct {
 950                 struct glink_msg msg;
 951                 struct intent_pair intents[];
 952         } __packed * msg;
 953
 954         const size_t msglen = struct_size(msg, intents, count);
 955         int ret;
 956         int i;
 957         unsigned long flags;
 958
 959         if (avail < msglen) {
 960                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 961                 return;
 962         }
 963
 964         spin_lock_irqsave(&glink->idr_lock, flags);
 965         channel = idr_find(&glink->rcids, cid);
 966         spin_unlock_irqrestore(&glink->idr_lock, flags);
 967         if (!channel) {
 968                 dev_err(glink->dev, "intents for non-existing channel\n");
 969                 qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 970                 return;
 971         }
 972
 973         msg = kmalloc(msglen, GFP_ATOMIC);
 974         if (!msg)
 975                 return;
 976
 977         qcom_glink_rx_peek(glink, msg, 0, msglen);
 978
 979         for (i = 0; i < count; ++i) {
 980                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 981                 if (!intent)
 982                         break;
 983
 984                 intent->id = le32_to_cpu(msg->intents[i].iid);
 985                 intent->size = le32_to_cpu(msg->intents[i].size);
 986
 987                 spin_lock_irqsave(&channel->intent_lock, flags);
 988                 ret = idr_alloc(&channel->riids, intent,
 989                                 intent->id, intent->id + 1, GFP_ATOMIC);
 990                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 991
 992                 if (ret < 0)
 993                         dev_err(glink->dev, "failed to store remote intent\n");
 994         }
 995
 996         kfree(msg);
 997         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 998 }
 999
1000 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
1001 {
1002         struct glink_channel *channel;
1003
1004         spin_lock(&glink->idr_lock);
1005         channel = idr_find(&glink->lcids, lcid);
1006         spin_unlock(&glink->idr_lock);
1007         if (!channel) {
1008                 dev_err(glink->dev, "Invalid open ack packet\n");
1009                 return -EINVAL;
1010         }
1011
1012         complete_all(&channel->open_ack);
1013
1014         return 0;
1015 }
1016
1017 void qcom_glink_native_rx(struct qcom_glink *glink)
1018 {
1019         struct glink_msg msg;
1020         unsigned int param1;
1021         unsigned int param2;
1022         unsigned int avail;
1023         unsigned int cmd;
1024         int ret = 0;
1025
1026         /* To wakeup any blocking writers */
1027         wake_up_all(&glink->tx_avail_notify);
1028
1029         for (;;) {
1030                 avail = qcom_glink_rx_avail(glink);
1031                 if (avail < sizeof(msg))
1032                         break;
1033
1034                 qcom_glink_rx_peek(glink, &msg, 0, sizeof(msg));
1035
1036                 cmd = le16_to_cpu(msg.cmd);
1037                 param1 = le16_to_cpu(msg.param1);
1038                 param2 = le32_to_cpu(msg.param2);
1039
1040                 switch (cmd) {
1041                 case GLINK_CMD_VERSION:
1042                 case GLINK_CMD_VERSION_ACK:
1043                 case GLINK_CMD_CLOSE:
1044                 case GLINK_CMD_CLOSE_ACK:
1045                 case GLINK_CMD_RX_INTENT_REQ:
1046                         ret = qcom_glink_rx_defer(glink, 0);
1047                         break;
1048                 case GLINK_CMD_OPEN_ACK:
1049                         ret = qcom_glink_rx_open_ack(glink, param1);
1050                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1051                         break;
1052                 case GLINK_CMD_OPEN:
1053                         ret = qcom_glink_rx_defer(glink, param2);
1054                         break;
1055                 case GLINK_CMD_TX_DATA:
1056                 case GLINK_CMD_TX_DATA_CONT:
1057                         ret = qcom_glink_rx_data(glink, avail);
1058                         break;
1059                 case GLINK_CMD_READ_NOTIF:
1060                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1061                         qcom_glink_tx_kick(glink);
1062                         break;
1063                 case GLINK_CMD_INTENT:
1064                         qcom_glink_handle_intent(glink, param1, param2, avail);
1065                         break;
1066                 case GLINK_CMD_RX_DONE:
1067                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1068                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1069                         break;
1070                 case GLINK_CMD_RX_DONE_W_REUSE:
1071                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1072                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1073                         break;
1074                 case GLINK_CMD_RX_INTENT_REQ_ACK:
1075                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1076                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1077                         break;
1078                 default:
1079                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1080                         ret = -EINVAL;
1081                         break;
1082                 }
1083
1084                 if (ret)
1085                         break;
1086         }
1087 }
1088 EXPORT_SYMBOL(qcom_glink_native_rx);
1089
1090 /* Locally initiated rpmsg_create_ept */
1091 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1092                                                      const char *name)
1093 {
1094         struct glink_channel *channel;
1095         int ret;
1096         unsigned long flags;
1097
1098         channel = qcom_glink_alloc_channel(glink, name);
1099         if (IS_ERR(channel))
1100                 return ERR_CAST(channel);
1101
1102         ret = qcom_glink_send_open_req(glink, channel);
1103         if (ret)
1104                 goto release_channel;
1105
1106         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1107         if (!ret)
1108                 goto err_timeout;
1109
1110         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1111         if (!ret)
1112                 goto err_timeout;
1113
1114         qcom_glink_send_open_ack(glink, channel);
1115
1116         return channel;
1117
1118 err_timeout:
1119         /* qcom_glink_send_open_req() did register the channel in lcids*/
1120         spin_lock_irqsave(&glink->idr_lock, flags);
1121         idr_remove(&glink->lcids, channel->lcid);
1122         spin_unlock_irqrestore(&glink->idr_lock, flags);
1123
1124 release_channel:
1125         /* Release qcom_glink_send_open_req() reference */
1126         kref_put(&channel->refcount, qcom_glink_channel_release);
1127         /* Release qcom_glink_alloc_channel() reference */
1128         kref_put(&channel->refcount, qcom_glink_channel_release);
1129
1130         return ERR_PTR(-ETIMEDOUT);
1131 }
1132
1133 /* Remote initiated rpmsg_create_ept */
1134 static int qcom_glink_create_remote(struct qcom_glink *glink,
1135                                     struct glink_channel *channel)
1136 {
1137         int ret;
1138
1139         qcom_glink_send_open_ack(glink, channel);
1140
1141         ret = qcom_glink_send_open_req(glink, channel);
1142         if (ret)
1143                 goto close_link;
1144
1145         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1146         if (!ret) {
1147                 ret = -ETIMEDOUT;
1148                 goto close_link;
1149         }
1150
1151         return 0;
1152
1153 close_link:
1154         /*
1155          * Send a close request to "undo" our open-ack. The close-ack will
1156          * release qcom_glink_send_open_req() reference and the last reference
1157          * will be relesed after receiving remote_close or transport unregister
1158          * by calling qcom_glink_native_remove().
1159          */
1160         qcom_glink_send_close_req(glink, channel);
1161
1162         return ret;
1163 }
1164
1165 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1166                                                     rpmsg_rx_cb_t cb,
1167                                                     void *priv,
1168                                                     struct rpmsg_channel_info
1169                                                                         chinfo)
1170 {
1171         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1172         struct glink_channel *channel;
1173         struct qcom_glink *glink = parent->glink;
1174         struct rpmsg_endpoint *ept;
1175         const char *name = chinfo.name;
1176         int cid;
1177         int ret;
1178         unsigned long flags;
1179
1180         spin_lock_irqsave(&glink->idr_lock, flags);
1181         idr_for_each_entry(&glink->rcids, channel, cid) {
1182                 if (!strcmp(channel->name, name))
1183                         break;
1184         }
1185         spin_unlock_irqrestore(&glink->idr_lock, flags);
1186
1187         if (!channel) {
1188                 channel = qcom_glink_create_local(glink, name);
1189                 if (IS_ERR(channel))
1190                         return NULL;
1191         } else {
1192                 ret = qcom_glink_create_remote(glink, channel);
1193                 if (ret)
1194                         return NULL;
1195         }
1196
1197         ept = &channel->ept;
1198         ept->rpdev = rpdev;
1199         ept->cb = cb;
1200         ept->priv = priv;
1201         ept->ops = &glink_endpoint_ops;
1202
1203         return ept;
1204 }
1205
1206 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1207 {
1208         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1209         struct device_node *np = rpdev->dev.of_node;
1210         struct qcom_glink *glink = channel->glink;
1211         struct glink_core_rx_intent *intent;
1212         const struct property *prop = NULL;
1213         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1214         int num_intents;
1215         int num_groups = 1;
1216         __be32 *val = defaults;
1217         int size;
1218
1219         if (glink->intentless || !completion_done(&channel->open_ack))
1220                 return 0;
1221
1222         prop = of_find_property(np, "qcom,intents", NULL);
1223         if (prop) {
1224                 val = prop->value;
1225                 num_groups = prop->length / sizeof(u32) / 2;
1226         }
1227
1228         /* Channel is now open, advertise base set of intents */
1229         while (num_groups--) {
1230                 size = be32_to_cpup(val++);
1231                 num_intents = be32_to_cpup(val++);
1232                 while (num_intents--) {
1233                         intent = qcom_glink_alloc_intent(glink, channel, size,
1234                                                          true);
1235                         if (!intent)
1236                                 break;
1237
1238                         qcom_glink_advertise_intent(glink, channel, intent);
1239                 }
1240         }
1241         return 0;
1242 }
1243
1244 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1245 {
1246         struct glink_channel *channel = to_glink_channel(ept);
1247         struct qcom_glink *glink = channel->glink;
1248         unsigned long flags;
1249
1250         spin_lock_irqsave(&channel->recv_lock, flags);
1251         channel->ept.cb = NULL;
1252         spin_unlock_irqrestore(&channel->recv_lock, flags);
1253
1254         /* Decouple the potential rpdev from the channel */
1255         channel->rpdev = NULL;
1256
1257         qcom_glink_send_close_req(glink, channel);
1258 }
1259
1260 static int qcom_glink_request_intent(struct qcom_glink *glink,
1261                                      struct glink_channel *channel,
1262                                      size_t size)
1263 {
1264         struct {
1265                 u16 id;
1266                 u16 cid;
1267                 u32 size;
1268         } __packed cmd;
1269
1270         int ret;
1271
1272         mutex_lock(&channel->intent_req_lock);
1273
1274         reinit_completion(&channel->intent_req_comp);
1275
1276         cmd.id = GLINK_CMD_RX_INTENT_REQ;
1277         cmd.cid = channel->lcid;
1278         cmd.size = size;
1279
1280         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1281         if (ret)
1282                 goto unlock;
1283
1284         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1285         if (!ret) {
1286                 dev_err(glink->dev, "intent request timed out\n");
1287                 ret = -ETIMEDOUT;
1288         } else {
1289                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1290         }
1291
1292 unlock:
1293         mutex_unlock(&channel->intent_req_lock);
1294         return ret;
1295 }
1296
1297 static int __qcom_glink_send(struct glink_channel *channel,
1298                              void *data, int len, bool wait)
1299 {
1300         struct qcom_glink *glink = channel->glink;
1301         struct glink_core_rx_intent *intent = NULL;
1302         struct glink_core_rx_intent *tmp;
1303         int iid = 0;
1304         struct {
1305                 struct glink_msg msg;
1306                 __le32 chunk_size;
1307                 __le32 left_size;
1308         } __packed req;
1309         int ret;
1310         unsigned long flags;
1311         int chunk_size = len;
1312         int left_size = 0;
1313
1314         if (!glink->intentless) {
1315                 while (!intent) {
1316                         spin_lock_irqsave(&channel->intent_lock, flags);
1317                         idr_for_each_entry(&channel->riids, tmp, iid) {
1318                                 if (tmp->size >= len && !tmp->in_use) {
1319                                         if (!intent)
1320                                                 intent = tmp;
1321                                         else if (intent->size > tmp->size)
1322                                                 intent = tmp;
1323                                         if (intent->size == len)
1324                                                 break;
1325                                 }
1326                         }
1327                         if (intent)
1328                                 intent->in_use = true;
1329                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1330
1331                         /* We found an available intent */
1332                         if (intent)
1333                                 break;
1334
1335                         if (!wait)
1336                                 return -EBUSY;
1337
1338                         ret = qcom_glink_request_intent(glink, channel, len);
1339                         if (ret < 0)
1340                                 return ret;
1341                 }
1342
1343                 iid = intent->id;
1344         }
1345
1346         if (wait && chunk_size > SZ_8K) {
1347                 chunk_size = SZ_8K;
1348                 left_size = len - chunk_size;
1349         }
1350         req.msg.cmd = cpu_to_le16(GLINK_CMD_TX_DATA);
1351         req.msg.param1 = cpu_to_le16(channel->lcid);
1352         req.msg.param2 = cpu_to_le32(iid);
1353         req.chunk_size = cpu_to_le32(chunk_size);
1354         req.left_size = cpu_to_le32(left_size);
1355
1356         ret = qcom_glink_tx(glink, &req, sizeof(req), data, chunk_size, wait);
1357
1358         /* Mark intent available if we failed */
1359         if (ret && intent) {
1360                 intent->in_use = false;
1361                 return ret;
1362         }
1363
1364         while (left_size > 0) {
1365                 data = (void *)((char *)data + chunk_size);
1366                 chunk_size = left_size;
1367                 if (chunk_size > SZ_8K)
1368                         chunk_size = SZ_8K;
1369                 left_size -= chunk_size;
1370
1371                 req.msg.cmd = cpu_to_le16(GLINK_CMD_TX_DATA_CONT);
1372                 req.msg.param1 = cpu_to_le16(channel->lcid);
1373                 req.msg.param2 = cpu_to_le32(iid);
1374                 req.chunk_size = cpu_to_le32(chunk_size);
1375                 req.left_size = cpu_to_le32(left_size);
1376
1377                 ret = qcom_glink_tx(glink, &req, sizeof(req), data,
1378                                     chunk_size, wait);
1379
1380                 /* Mark intent available if we failed */
1381                 if (ret && intent) {
1382                         intent->in_use = false;
1383                         break;
1384                 }
1385         }
1386         return ret;
1387 }
1388
1389 static int qcom_glink_send(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, true);
1394 }
1395
1396 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1397 {
1398         struct glink_channel *channel = to_glink_channel(ept);
1399
1400         return __qcom_glink_send(channel, data, len, false);
1401 }
1402
1403 static int qcom_glink_sendto(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, true);
1408 }
1409
1410 static int qcom_glink_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1411 {
1412         struct glink_channel *channel = to_glink_channel(ept);
1413
1414         return __qcom_glink_send(channel, data, len, false);
1415 }
1416
1417 /*
1418  * Finds the device_node for the glink child interested in this channel.
1419  */
1420 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1421                                                     const char *channel)
1422 {
1423         struct device_node *child;
1424         const char *name;
1425         const char *key;
1426         int ret;
1427
1428         for_each_available_child_of_node(node, child) {
1429                 key = "qcom,glink-channels";
1430                 ret = of_property_read_string(child, key, &name);
1431                 if (ret)
1432                         continue;
1433
1434                 if (strcmp(name, channel) == 0)
1435                         return child;
1436         }
1437
1438         return NULL;
1439 }
1440
1441 static const struct rpmsg_device_ops glink_device_ops = {
1442         .create_ept = qcom_glink_create_ept,
1443         .announce_create = qcom_glink_announce_create,
1444 };
1445
1446 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1447         .destroy_ept = qcom_glink_destroy_ept,
1448         .send = qcom_glink_send,
1449         .sendto = qcom_glink_sendto,
1450         .trysend = qcom_glink_trysend,
1451         .trysendto = qcom_glink_trysendto,
1452 };
1453
1454 static void qcom_glink_rpdev_release(struct device *dev)
1455 {
1456         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1457
1458         kfree(rpdev->driver_override);
1459         kfree(rpdev);
1460 }
1461
1462 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1463                               char *name)
1464 {
1465         struct glink_channel *channel;
1466         struct rpmsg_device *rpdev;
1467         bool create_device = false;
1468         struct device_node *node;
1469         int lcid;
1470         int ret;
1471         unsigned long flags;
1472
1473         spin_lock_irqsave(&glink->idr_lock, flags);
1474         idr_for_each_entry(&glink->lcids, channel, lcid) {
1475                 if (!strcmp(channel->name, name))
1476                         break;
1477         }
1478         spin_unlock_irqrestore(&glink->idr_lock, flags);
1479
1480         if (!channel) {
1481                 channel = qcom_glink_alloc_channel(glink, name);
1482                 if (IS_ERR(channel))
1483                         return PTR_ERR(channel);
1484
1485                 /* The opening dance was initiated by the remote */
1486                 create_device = true;
1487         }
1488
1489         spin_lock_irqsave(&glink->idr_lock, flags);
1490         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1491         if (ret < 0) {
1492                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1493                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1494                 goto free_channel;
1495         }
1496         channel->rcid = ret;
1497         spin_unlock_irqrestore(&glink->idr_lock, flags);
1498
1499         complete_all(&channel->open_req);
1500
1501         if (create_device) {
1502                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1503                 if (!rpdev) {
1504                         ret = -ENOMEM;
1505                         goto rcid_remove;
1506                 }
1507
1508                 rpdev->ept = &channel->ept;
1509                 strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE);
1510                 rpdev->src = RPMSG_ADDR_ANY;
1511                 rpdev->dst = RPMSG_ADDR_ANY;
1512                 rpdev->ops = &glink_device_ops;
1513
1514                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1515                 rpdev->dev.of_node = node;
1516                 rpdev->dev.parent = glink->dev;
1517                 rpdev->dev.release = qcom_glink_rpdev_release;
1518
1519                 ret = rpmsg_register_device(rpdev);
1520                 if (ret)
1521                         goto rcid_remove;
1522
1523                 channel->rpdev = rpdev;
1524         }
1525
1526         return 0;
1527
1528 rcid_remove:
1529         spin_lock_irqsave(&glink->idr_lock, flags);
1530         idr_remove(&glink->rcids, channel->rcid);
1531         channel->rcid = 0;
1532         spin_unlock_irqrestore(&glink->idr_lock, flags);
1533 free_channel:
1534         /* Release the reference, iff we took it */
1535         if (create_device)
1536                 kref_put(&channel->refcount, qcom_glink_channel_release);
1537
1538         return ret;
1539 }
1540
1541 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1542 {
1543         struct rpmsg_channel_info chinfo;
1544         struct glink_channel *channel;
1545         unsigned long flags;
1546
1547         spin_lock_irqsave(&glink->idr_lock, flags);
1548         channel = idr_find(&glink->rcids, rcid);
1549         spin_unlock_irqrestore(&glink->idr_lock, flags);
1550         if (WARN(!channel, "close request on unknown channel\n"))
1551                 return;
1552
1553         /* cancel pending rx_done work */
1554         cancel_work_sync(&channel->intent_work);
1555
1556         if (channel->rpdev) {
1557                 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1558                 chinfo.src = RPMSG_ADDR_ANY;
1559                 chinfo.dst = RPMSG_ADDR_ANY;
1560
1561                 rpmsg_unregister_device(glink->dev, &chinfo);
1562         }
1563         channel->rpdev = NULL;
1564
1565         qcom_glink_send_close_ack(glink, channel->rcid);
1566
1567         spin_lock_irqsave(&glink->idr_lock, flags);
1568         idr_remove(&glink->rcids, channel->rcid);
1569         channel->rcid = 0;
1570         spin_unlock_irqrestore(&glink->idr_lock, flags);
1571
1572         kref_put(&channel->refcount, qcom_glink_channel_release);
1573 }
1574
1575 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1576 {
1577         struct rpmsg_channel_info chinfo;
1578         struct glink_channel *channel;
1579         unsigned long flags;
1580
1581         /* To wakeup any blocking writers */
1582         wake_up_all(&glink->tx_avail_notify);
1583
1584         spin_lock_irqsave(&glink->idr_lock, flags);
1585         channel = idr_find(&glink->lcids, lcid);
1586         if (WARN(!channel, "close ack on unknown channel\n")) {
1587                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1588                 return;
1589         }
1590
1591         idr_remove(&glink->lcids, channel->lcid);
1592         channel->lcid = 0;
1593         spin_unlock_irqrestore(&glink->idr_lock, flags);
1594
1595         /* Decouple the potential rpdev from the channel */
1596         if (channel->rpdev) {
1597                 strscpy(chinfo.name, channel->name, sizeof(chinfo.name));
1598                 chinfo.src = RPMSG_ADDR_ANY;
1599                 chinfo.dst = RPMSG_ADDR_ANY;
1600
1601                 rpmsg_unregister_device(glink->dev, &chinfo);
1602         }
1603         channel->rpdev = NULL;
1604
1605         kref_put(&channel->refcount, qcom_glink_channel_release);
1606 }
1607
1608 static void qcom_glink_work(struct work_struct *work)
1609 {
1610         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1611                                                 rx_work);
1612         struct glink_defer_cmd *dcmd;
1613         struct glink_msg *msg;
1614         unsigned long flags;
1615         unsigned int param1;
1616         unsigned int param2;
1617         unsigned int cmd;
1618
1619         for (;;) {
1620                 spin_lock_irqsave(&glink->rx_lock, flags);
1621                 if (list_empty(&glink->rx_queue)) {
1622                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1623                         break;
1624                 }
1625                 dcmd = list_first_entry(&glink->rx_queue,
1626                                         struct glink_defer_cmd, node);
1627                 list_del(&dcmd->node);
1628                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1629
1630                 msg = &dcmd->msg;
1631                 cmd = le16_to_cpu(msg->cmd);
1632                 param1 = le16_to_cpu(msg->param1);
1633                 param2 = le32_to_cpu(msg->param2);
1634
1635                 switch (cmd) {
1636                 case GLINK_CMD_VERSION:
1637                         qcom_glink_receive_version(glink, param1, param2);
1638                         break;
1639                 case GLINK_CMD_VERSION_ACK:
1640                         qcom_glink_receive_version_ack(glink, param1, param2);
1641                         break;
1642                 case GLINK_CMD_OPEN:
1643                         qcom_glink_rx_open(glink, param1, msg->data);
1644                         break;
1645                 case GLINK_CMD_CLOSE:
1646                         qcom_glink_rx_close(glink, param1);
1647                         break;
1648                 case GLINK_CMD_CLOSE_ACK:
1649                         qcom_glink_rx_close_ack(glink, param1);
1650                         break;
1651                 case GLINK_CMD_RX_INTENT_REQ:
1652                         qcom_glink_handle_intent_req(glink, param1, param2);
1653                         break;
1654                 default:
1655                         WARN(1, "Unknown defer object %d\n", cmd);
1656                         break;
1657                 }
1658
1659                 kfree(dcmd);
1660         }
1661 }
1662
1663 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1664 {
1665         struct glink_defer_cmd *dcmd;
1666         struct glink_defer_cmd *tmp;
1667
1668         /* cancel any pending deferred rx_work */
1669         cancel_work_sync(&glink->rx_work);
1670
1671         list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1672                 kfree(dcmd);
1673 }
1674
1675 static ssize_t rpmsg_name_show(struct device *dev,
1676                                struct device_attribute *attr, char *buf)
1677 {
1678         int ret = 0;
1679         const char *name;
1680
1681         ret = of_property_read_string(dev->of_node, "label", &name);
1682         if (ret < 0)
1683                 name = dev->of_node->name;
1684
1685         return sysfs_emit(buf, "%s\n", name);
1686 }
1687 static DEVICE_ATTR_RO(rpmsg_name);
1688
1689 static struct attribute *qcom_glink_attrs[] = {
1690         &dev_attr_rpmsg_name.attr,
1691         NULL
1692 };
1693 ATTRIBUTE_GROUPS(qcom_glink);
1694
1695 static void qcom_glink_device_release(struct device *dev)
1696 {
1697         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1698         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1699
1700         /* Release qcom_glink_alloc_channel() reference */
1701         kref_put(&channel->refcount, qcom_glink_channel_release);
1702         kfree(rpdev->driver_override);
1703         kfree(rpdev);
1704 }
1705
1706 static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1707 {
1708         struct rpmsg_device *rpdev;
1709         struct glink_channel *channel;
1710
1711         rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1712         if (!rpdev)
1713                 return -ENOMEM;
1714
1715         channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1716         if (IS_ERR(channel)) {
1717                 kfree(rpdev);
1718                 return PTR_ERR(channel);
1719         }
1720         channel->rpdev = rpdev;
1721
1722         rpdev->ept = &channel->ept;
1723         rpdev->ops = &glink_device_ops;
1724         rpdev->dev.parent = glink->dev;
1725         rpdev->dev.release = qcom_glink_device_release;
1726
1727         return rpmsg_ctrldev_register_device(rpdev);
1728 }
1729
1730 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1731                                            unsigned long features,
1732                                            struct qcom_glink_pipe *rx,
1733                                            struct qcom_glink_pipe *tx,
1734                                            bool intentless)
1735 {
1736         int ret;
1737         struct qcom_glink *glink;
1738
1739         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1740         if (!glink)
1741                 return ERR_PTR(-ENOMEM);
1742
1743         glink->dev = dev;
1744         glink->tx_pipe = tx;
1745         glink->rx_pipe = rx;
1746
1747         glink->features = features;
1748         glink->intentless = intentless;
1749
1750         spin_lock_init(&glink->tx_lock);
1751         spin_lock_init(&glink->rx_lock);
1752         INIT_LIST_HEAD(&glink->rx_queue);
1753         INIT_WORK(&glink->rx_work, qcom_glink_work);
1754         init_waitqueue_head(&glink->tx_avail_notify);
1755
1756         spin_lock_init(&glink->idr_lock);
1757         idr_init(&glink->lcids);
1758         idr_init(&glink->rcids);
1759
1760         glink->dev->groups = qcom_glink_groups;
1761
1762         ret = device_add_groups(dev, qcom_glink_groups);
1763         if (ret)
1764                 dev_err(dev, "failed to add groups\n");
1765
1766         ret = qcom_glink_send_version(glink);
1767         if (ret)
1768                 return ERR_PTR(ret);
1769
1770         ret = qcom_glink_create_chrdev(glink);
1771         if (ret)
1772                 dev_err(glink->dev, "failed to register chrdev\n");
1773
1774         return glink;
1775 }
1776 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1777
1778 static int qcom_glink_remove_device(struct device *dev, void *data)
1779 {
1780         device_unregister(dev);
1781
1782         return 0;
1783 }
1784
1785 void qcom_glink_native_remove(struct qcom_glink *glink)
1786 {
1787         struct glink_channel *channel;
1788         unsigned long flags;
1789         int cid;
1790         int ret;
1791
1792         qcom_glink_cancel_rx_work(glink);
1793
1794         /* Fail all attempts at sending messages */
1795         spin_lock_irqsave(&glink->tx_lock, flags);
1796         glink->abort_tx = true;
1797         wake_up_all(&glink->tx_avail_notify);
1798         spin_unlock_irqrestore(&glink->tx_lock, flags);
1799
1800         /* Abort any senders waiting for intent requests */
1801         spin_lock_irqsave(&glink->idr_lock, flags);
1802         idr_for_each_entry(&glink->lcids, channel, cid)
1803                 qcom_glink_intent_req_abort(channel);
1804         spin_unlock_irqrestore(&glink->idr_lock, flags);
1805
1806         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1807         if (ret)
1808                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1809
1810         /* Release any defunct local channels, waiting for close-ack */
1811         idr_for_each_entry(&glink->lcids, channel, cid)
1812                 kref_put(&channel->refcount, qcom_glink_channel_release);
1813
1814         /* Release any defunct local channels, waiting for close-req */
1815         idr_for_each_entry(&glink->rcids, channel, cid)
1816                 kref_put(&channel->refcount, qcom_glink_channel_release);
1817
1818         idr_destroy(&glink->lcids);
1819         idr_destroy(&glink->rcids);
1820 }
1821 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1822
1823 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1824 MODULE_LICENSE("GPL v2");