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/wait.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  * @rx_pipe:    pipe object for receive FIFO
  82  * @tx_pipe:    pipe object for transmit FIFO
  83  * @rx_work:    worker for handling received control messages
  84  * @rx_lock:    protects the @rx_queue
  85  * @rx_queue:   queue of received control messages to be processed in @rx_work
  86  * @tx_lock:    synchronizes operations on the tx fifo
  87  * @idr_lock:   synchronizes @lcids and @rcids modifications
  88  * @lcids:      idr of all channels with a known local channel id
  89  * @rcids:      idr of all channels with a known remote channel id
  90  * @features:   remote features
  91  * @intentless: flag to indicate that there is no intent
  92  * @tx_avail_notify: Waitqueue for pending tx tasks
  93  * @sent_read_notify: flag to check cmd sent or not
  94  * @abort_tx:   flag indicating that all tx attempts should fail
  95  */
  96 struct qcom_glink {
  97         struct device *dev;
  98
  99         struct qcom_glink_pipe *rx_pipe;
 100         struct qcom_glink_pipe *tx_pipe;
 101
 102         struct work_struct rx_work;
 103         spinlock_t rx_lock;
 104         struct list_head rx_queue;
 105
 106         spinlock_t tx_lock;
 107
 108         spinlock_t idr_lock;
 109         struct idr lcids;
 110         struct idr rcids;
 111         unsigned long features;
 112
 113         bool intentless;
 114         wait_queue_head_t tx_avail_notify;
 115         bool sent_read_notify;
 116
 117         bool abort_tx;
 118 };
 119
 120 enum {
 121         GLINK_STATE_CLOSED,
 122         GLINK_STATE_OPENING,
 123         GLINK_STATE_OPEN,
 124         GLINK_STATE_CLOSING,
 125 };
 126
 127 /**
 128  * struct glink_channel - internal representation of a channel
 129  * @rpdev:      rpdev reference, only used for primary endpoints
 130  * @ept:        rpmsg endpoint this channel is associated with
 131  * @glink:      qcom_glink context handle
 132  * @refcount:   refcount for the channel object
 133  * @recv_lock:  guard for @ept.cb
 134  * @name:       unique channel name/identifier
 135  * @lcid:       channel id, in local space
 136  * @rcid:       channel id, in remote space
 137  * @intent_lock: lock for protection of @liids, @riids
 138  * @liids:      idr of all local intents
 139  * @riids:      idr of all remote intents
 140  * @intent_work: worker responsible for transmitting rx_done packets
 141  * @done_intents: list of intents that needs to be announced rx_done
 142  * @buf:        receive buffer, for gathering fragments
 143  * @buf_offset: write offset in @buf
 144  * @buf_size:   size of current @buf
 145  * @open_ack:   completed once remote has acked the open-request
 146  * @open_req:   completed once open-request has been received
 147  * @intent_req_lock: Synchronises multiple intent requests
 148  * @intent_req_result: Result of intent request
 149  * @intent_received: flag indicating that an intent has been received
 150  * @intent_req_wq: wait queue for intent_req signalling
 151  */
 152 struct glink_channel {
 153         struct rpmsg_endpoint ept;
 154
 155         struct rpmsg_device *rpdev;
 156         struct qcom_glink *glink;
 157
 158         struct kref refcount;
 159
 160         spinlock_t recv_lock;
 161
 162         char *name;
 163         unsigned int lcid;
 164         unsigned int rcid;
 165
 166         spinlock_t intent_lock;
 167         struct idr liids;
 168         struct idr riids;
 169         struct work_struct intent_work;
 170         struct list_head done_intents;
 171
 172         struct glink_core_rx_intent *buf;
 173         int buf_offset;
 174         int buf_size;
 175
 176         struct completion open_ack;
 177         struct completion open_req;
 178
 179         struct mutex intent_req_lock;
 180         int intent_req_result;
 181         bool intent_received;
 182         wait_queue_head_t intent_req_wq;
 183 };
 184
 185 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 186
 187 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 188
 189 #define GLINK_CMD_VERSION               0
 190 #define GLINK_CMD_VERSION_ACK           1
 191 #define GLINK_CMD_OPEN                  2
 192 #define GLINK_CMD_CLOSE                 3
 193 #define GLINK_CMD_OPEN_ACK              4
 194 #define GLINK_CMD_INTENT                5
 195 #define GLINK_CMD_RX_DONE               6
 196 #define GLINK_CMD_RX_INTENT_REQ         7
 197 #define GLINK_CMD_RX_INTENT_REQ_ACK     8
 198 #define GLINK_CMD_TX_DATA               9
 199 #define GLINK_CMD_CLOSE_ACK             11
 200 #define GLINK_CMD_TX_DATA_CONT          12
 201 #define GLINK_CMD_READ_NOTIF            13
 202 #define GLINK_CMD_RX_DONE_W_REUSE       14
 203
 204 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 205
 206 static void qcom_glink_rx_done_work(struct work_struct *work);
 207
 208 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 209                                                       const char *name)
 210 {
 211         struct glink_channel *channel;
 212
 213         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 214         if (!channel)
 215                 return ERR_PTR(-ENOMEM);
 216
 217         /* Setup glink internal glink_channel data */
 218         spin_lock_init(&channel->recv_lock);
 219         spin_lock_init(&channel->intent_lock);
 220         mutex_init(&channel->intent_req_lock);
 221
 222         channel->glink = glink;
 223         channel->name = kstrdup(name, GFP_KERNEL);
 224
 225         init_completion(&channel->open_req);
 226         init_completion(&channel->open_ack);
 227         init_waitqueue_head(&channel->intent_req_wq);
 228
 229         INIT_LIST_HEAD(&channel->done_intents);
 230         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 231
 232         idr_init(&channel->liids);
 233         idr_init(&channel->riids);
 234         kref_init(&channel->refcount);
 235
 236         return channel;
 237 }
 238
 239 static void qcom_glink_channel_release(struct kref *ref)
 240 {
 241         struct glink_channel *channel = container_of(ref, struct glink_channel,
 242                                                      refcount);
 243         struct glink_core_rx_intent *intent;
 244         struct glink_core_rx_intent *tmp;
 245         unsigned long flags;
 246         int iid;
 247
 248         /* cancel pending rx_done work */
 249         cancel_work_sync(&channel->intent_work);
 250
 251         spin_lock_irqsave(&channel->intent_lock, flags);
 252         /* Free all non-reuse intents pending rx_done work */
 253         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 254                 if (!intent->reuse) {
 255                         kfree(intent->data);
 256                         kfree(intent);
 257                 }
 258         }
 259
 260         idr_for_each_entry(&channel->liids, tmp, iid) {
 261                 kfree(tmp->data);
 262                 kfree(tmp);
 263         }
 264         idr_destroy(&channel->liids);
 265
 266         idr_for_each_entry(&channel->riids, tmp, iid)
 267                 kfree(tmp);
 268         idr_destroy(&channel->riids);
 269         spin_unlock_irqrestore(&channel->intent_lock, flags);
 270
 271         kfree(channel->name);
 272         kfree(channel);
 273 }
 274
 275 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 276 {
 277         return glink->rx_pipe->avail(glink->rx_pipe);
 278 }
 279
 280 static void qcom_glink_rx_peek(struct qcom_glink *glink,
 281                                void *data, unsigned int offset, size_t count)
 282 {
 283         glink->rx_pipe->peek(glink->rx_pipe, data, offset, count);
 284 }
 285
 286 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 287 {
 288         glink->rx_pipe->advance(glink->rx_pipe, count);
 289 }
 290
 291 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 292 {
 293         return glink->tx_pipe->avail(glink->tx_pipe);
 294 }
 295
 296 static void qcom_glink_tx_write(struct qcom_glink *glink,
 297                                 const void *hdr, size_t hlen,
 298                                 const void *data, size_t dlen)
 299 {
 300         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 301 }
 302
 303 static void qcom_glink_tx_kick(struct qcom_glink *glink)
 304 {
 305         glink->tx_pipe->kick(glink->tx_pipe);
 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(GLINK_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         qcom_glink_tx_kick(glink);
 319 }
 320
 321 static int qcom_glink_tx(struct qcom_glink *glink,
 322                          const void *hdr, size_t hlen,
 323                          const void *data, size_t dlen, bool wait)
 324 {
 325         unsigned int tlen = hlen + dlen;
 326         unsigned long flags;
 327         int ret = 0;
 328
 329         /* Reject packets that are too big */
 330         if (tlen >= glink->tx_pipe->length)
 331                 return -EINVAL;
 332
 333         spin_lock_irqsave(&glink->tx_lock, flags);
 334
 335         if (glink->abort_tx) {
 336                 ret = -EIO;
 337                 goto out;
 338         }
 339
 340         while (qcom_glink_tx_avail(glink) < tlen) {
 341                 if (!wait) {
 342                         ret = -EAGAIN;
 343                         goto out;
 344                 }
 345
 346                 if (glink->abort_tx) {
 347                         ret = -EIO;
 348                         goto out;
 349                 }
 350
 351                 if (!glink->sent_read_notify) {
 352                         glink->sent_read_notify = true;
 353                         qcom_glink_send_read_notify(glink);
 354                 }
 355
 356                 /* Wait without holding the tx_lock */
 357                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 358
 359                 wait_event_timeout(glink->tx_avail_notify,
 360                                    qcom_glink_tx_avail(glink) >= tlen, 10 * HZ);
 361
 362                 spin_lock_irqsave(&glink->tx_lock, flags);
 363
 364                 if (qcom_glink_tx_avail(glink) >= tlen)
 365                         glink->sent_read_notify = false;
 366         }
 367
 368         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 369         qcom_glink_tx_kick(glink);
 370
 371 out:
 372         spin_unlock_irqrestore(&glink->tx_lock, flags);
 373
 374         return ret;
 375 }
 376
 377 static int qcom_glink_send_version(struct qcom_glink *glink)
 378 {
 379         struct glink_msg msg;
 380
 381         msg.cmd = cpu_to_le16(GLINK_CMD_VERSION);
 382         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 383         msg.param2 = cpu_to_le32(glink->features);
 384
 385         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 386 }
 387
 388 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 389 {
 390         struct glink_msg msg;
 391
 392         msg.cmd = cpu_to_le16(GLINK_CMD_VERSION_ACK);
 393         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 394         msg.param2 = cpu_to_le32(glink->features);
 395
 396         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 397 }
 398
 399 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 400                                      struct glink_channel *channel)
 401 {
 402         struct glink_msg msg;
 403
 404         msg.cmd = cpu_to_le16(GLINK_CMD_OPEN_ACK);
 405         msg.param1 = cpu_to_le16(channel->rcid);
 406         msg.param2 = cpu_to_le32(0);
 407
 408         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 409 }
 410
 411 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 412                                              unsigned int cid, bool granted)
 413 {
 414         struct glink_channel *channel;
 415         unsigned long flags;
 416
 417         spin_lock_irqsave(&glink->idr_lock, flags);
 418         channel = idr_find(&glink->rcids, cid);
 419         spin_unlock_irqrestore(&glink->idr_lock, flags);
 420         if (!channel) {
 421                 dev_err(glink->dev, "unable to find channel\n");
 422                 return;
 423         }
 424
 425         WRITE_ONCE(channel->intent_req_result, granted);
 426         wake_up_all(&channel->intent_req_wq);
 427 }
 428
 429 static void qcom_glink_intent_req_abort(struct glink_channel *channel)
 430 {
 431         WRITE_ONCE(channel->intent_req_result, 0);
 432         wake_up_all(&channel->intent_req_wq);
 433 }
 434
 435 /**
 436  * qcom_glink_send_open_req() - send a GLINK_CMD_OPEN request to the remote
 437  * @glink: Ptr to the glink edge
 438  * @channel: Ptr to the channel that the open req is sent
 439  *
 440  * Allocates a local channel id and sends a GLINK_CMD_OPEN message to the remote.
 441  * Will return with refcount held, regardless of outcome.
 442  *
 443  * Return: 0 on success, negative errno otherwise.
 444  */
 445 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 446                                     struct glink_channel *channel)
 447 {
 448         struct {
 449                 struct glink_msg msg;
 450                 u8 name[GLINK_NAME_SIZE];
 451         } __packed req;
 452         int name_len = strlen(channel->name) + 1;
 453         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 454         int ret;
 455         unsigned long flags;
 456
 457         kref_get(&channel->refcount);
 458
 459         spin_lock_irqsave(&glink->idr_lock, flags);
 460         ret = idr_alloc_cyclic(&glink->lcids, channel,
 461                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 462                                GFP_ATOMIC);
 463         spin_unlock_irqrestore(&glink->idr_lock, flags);
 464         if (ret < 0)
 465                 return ret;
 466
 467         channel->lcid = ret;
 468
 469         req.msg.cmd = cpu_to_le16(GLINK_CMD_OPEN);
 470         req.msg.param1 = cpu_to_le16(channel->lcid);
 471         req.msg.param2 = cpu_to_le32(name_len);
 472         strcpy(req.name, channel->name);
 473
 474         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 475         if (ret)
 476                 goto remove_idr;
 477
 478         return 0;
 479
 480 remove_idr:
 481         spin_lock_irqsave(&glink->idr_lock, flags);
 482         idr_remove(&glink->lcids, channel->lcid);
 483         channel->lcid = 0;
 484         spin_unlock_irqrestore(&glink->idr_lock, flags);
 485
 486         return ret;
 487 }
 488
 489 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 490                                       struct glink_channel *channel)
 491 {
 492         struct glink_msg req;
 493
 494         req.cmd = cpu_to_le16(GLINK_CMD_CLOSE);
 495         req.param1 = cpu_to_le16(channel->lcid);
 496         req.param2 = 0;
 497
 498         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 499 }
 500
 501 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 502                                       unsigned int rcid)
 503 {
 504         struct glink_msg req;
 505
 506         req.cmd = cpu_to_le16(GLINK_CMD_CLOSE_ACK);
 507         req.param1 = cpu_to_le16(rcid);
 508         req.param2 = 0;
 509
 510         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 511 }
 512
 513 static void qcom_glink_rx_done_work(struct work_struct *work)
 514 {
 515         struct glink_channel *channel = container_of(work, struct glink_channel,
 516                                                      intent_work);
 517         struct qcom_glink *glink = channel->glink;
 518         struct glink_core_rx_intent *intent, *tmp;
 519         struct {
 520                 u16 id;
 521                 u16 lcid;
 522                 u32 liid;
 523         } __packed cmd;
 524
 525         unsigned int cid = channel->lcid;
 526         unsigned int iid;
 527         bool reuse;
 528         unsigned long flags;
 529
 530         spin_lock_irqsave(&channel->intent_lock, flags);
 531         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 532                 list_del(&intent->node);
 533                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 534                 iid = intent->id;
 535                 reuse = intent->reuse;
 536
 537                 cmd.id = reuse ? GLINK_CMD_RX_DONE_W_REUSE : GLINK_CMD_RX_DONE;
 538                 cmd.lcid = cid;
 539                 cmd.liid = iid;
 540
 541                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 542                 if (!reuse) {
 543                         kfree(intent->data);
 544                         kfree(intent);
 545                 }
 546                 spin_lock_irqsave(&channel->intent_lock, flags);
 547         }
 548         spin_unlock_irqrestore(&channel->intent_lock, flags);
 549 }
 550
 551 static void qcom_glink_rx_done(struct qcom_glink *glink,
 552                                struct glink_channel *channel,
 553                                struct glink_core_rx_intent *intent)
 554 {
 555         /* We don't send RX_DONE to intentless systems */
 556         if (glink->intentless) {
 557                 kfree(intent->data);
 558                 kfree(intent);
 559                 return;
 560         }
 561
 562         /* Take it off the tree of receive intents */
 563         if (!intent->reuse) {
 564                 spin_lock(&channel->intent_lock);
 565                 idr_remove(&channel->liids, intent->id);
 566                 spin_unlock(&channel->intent_lock);
 567         }
 568
 569         /* Schedule the sending of a rx_done indication */
 570         spin_lock(&channel->intent_lock);
 571         list_add_tail(&intent->node, &channel->done_intents);
 572         spin_unlock(&channel->intent_lock);
 573
 574         schedule_work(&channel->intent_work);
 575 }
 576
 577 /**
 578  * qcom_glink_receive_version() - receive version/features from remote system
 579  *
 580  * @glink:      pointer to transport interface
 581  * @version:    remote version
 582  * @features:   remote features
 583  *
 584  * This function is called in response to a remote-initiated version/feature
 585  * negotiation sequence.
 586  */
 587 static void qcom_glink_receive_version(struct qcom_glink *glink,
 588                                        u32 version,
 589                                        u32 features)
 590 {
 591         switch (version) {
 592         case 0:
 593                 break;
 594         case GLINK_VERSION_1:
 595                 glink->features &= features;
 596                 fallthrough;
 597         default:
 598                 qcom_glink_send_version_ack(glink);
 599                 break;
 600         }
 601 }
 602
 603 /**
 604  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 605  *
 606  * @glink:      pointer to transport interface
 607  * @version:    remote version response
 608  * @features:   remote features response
 609  *
 610  * This function is called in response to a local-initiated version/feature
 611  * negotiation sequence and is the counter-offer from the remote side based
 612  * upon the initial version and feature set requested.
 613  */
 614 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 615                                            u32 version,
 616                                            u32 features)
 617 {
 618         switch (version) {
 619         case 0:
 620                 /* Version negotiation failed */
 621                 break;
 622         case GLINK_VERSION_1:
 623                 if (features == glink->features)
 624                         break;
 625
 626                 glink->features &= features;
 627                 fallthrough;
 628         default:
 629                 qcom_glink_send_version(glink);
 630                 break;
 631         }
 632 }
 633
 634 /**
 635  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 636  *      wire format and transmit
 637  * @glink:      The transport to transmit on.
 638  * @channel:    The glink channel
 639  * @granted:    The request response to encode.
 640  *
 641  * Return: 0 on success or standard Linux error code.
 642  */
 643 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 644                                           struct glink_channel *channel,
 645                                           bool granted)
 646 {
 647         struct glink_msg msg;
 648
 649         msg.cmd = cpu_to_le16(GLINK_CMD_RX_INTENT_REQ_ACK);
 650         msg.param1 = cpu_to_le16(channel->lcid);
 651         msg.param2 = cpu_to_le32(granted);
 652
 653         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 654
 655         return 0;
 656 }
 657
 658 /**
 659  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 660  *                         transmit
 661  * @glink:      The transport to transmit on.
 662  * @channel:    The local channel
 663  * @intent:     The intent to pass on to remote.
 664  *
 665  * Return: 0 on success or standard Linux error code.
 666  */
 667 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 668                                        struct glink_channel *channel,
 669                                        struct glink_core_rx_intent *intent)
 670 {
 671         struct command {
 672                 __le16 id;
 673                 __le16 lcid;
 674                 __le32 count;
 675                 __le32 size;
 676                 __le32 liid;
 677         } __packed;
 678         struct command cmd;
 679
 680         cmd.id = cpu_to_le16(GLINK_CMD_INTENT);
 681         cmd.lcid = cpu_to_le16(channel->lcid);
 682         cmd.count = cpu_to_le32(1);
 683         cmd.size = cpu_to_le32(intent->size);
 684         cmd.liid = cpu_to_le32(intent->id);
 685
 686         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 687
 688         return 0;
 689 }
 690
 691 static struct glink_core_rx_intent *
 692 qcom_glink_alloc_intent(struct qcom_glink *glink,
 693                         struct glink_channel *channel,
 694                         size_t size,
 695                         bool reuseable)
 696 {
 697         struct glink_core_rx_intent *intent;
 698         int ret;
 699         unsigned long flags;
 700
 701         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 702         if (!intent)
 703                 return NULL;
 704
 705         intent->data = kzalloc(size, GFP_KERNEL);
 706         if (!intent->data)
 707                 goto free_intent;
 708
 709         spin_lock_irqsave(&channel->intent_lock, flags);
 710         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 711         if (ret < 0) {
 712                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 713                 goto free_data;
 714         }
 715         spin_unlock_irqrestore(&channel->intent_lock, flags);
 716
 717         intent->id = ret;
 718         intent->size = size;
 719         intent->reuse = reuseable;
 720
 721         return intent;
 722
 723 free_data:
 724         kfree(intent->data);
 725 free_intent:
 726         kfree(intent);
 727         return NULL;
 728 }
 729
 730 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 731                                       u32 cid, uint32_t iid,
 732                                       bool reuse)
 733 {
 734         struct glink_core_rx_intent *intent;
 735         struct glink_channel *channel;
 736         unsigned long flags;
 737
 738         spin_lock_irqsave(&glink->idr_lock, flags);
 739         channel = idr_find(&glink->rcids, cid);
 740         spin_unlock_irqrestore(&glink->idr_lock, flags);
 741         if (!channel) {
 742                 dev_err(glink->dev, "invalid channel id received\n");
 743                 return;
 744         }
 745
 746         spin_lock_irqsave(&channel->intent_lock, flags);
 747         intent = idr_find(&channel->riids, iid);
 748
 749         if (!intent) {
 750                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 751                 dev_err(glink->dev, "invalid intent id received\n");
 752                 return;
 753         }
 754
 755         intent->in_use = false;
 756
 757         if (!reuse) {
 758                 idr_remove(&channel->riids, intent->id);
 759                 kfree(intent);
 760         }
 761         spin_unlock_irqrestore(&channel->intent_lock, flags);
 762
 763         if (reuse) {
 764                 WRITE_ONCE(channel->intent_received, true);
 765                 wake_up_all(&channel->intent_req_wq);
 766         }
 767 }
 768
 769 /**
 770  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 771  *                                          from remote side
 772  * @glink:      Pointer to the transport interface
 773  * @cid:        Remote channel ID
 774  * @size:       size of the intent
 775  *
 776  * The function searches for the local channel to which the request for
 777  * rx_intent has arrived and allocates and notifies the remote back
 778  */
 779 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 780                                          u32 cid, size_t size)
 781 {
 782         struct glink_core_rx_intent *intent;
 783         struct glink_channel *channel;
 784         unsigned long flags;
 785
 786         spin_lock_irqsave(&glink->idr_lock, flags);
 787         channel = idr_find(&glink->rcids, cid);
 788         spin_unlock_irqrestore(&glink->idr_lock, flags);
 789
 790         if (!channel) {
 791                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 792                 return;
 793         }
 794
 795         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 796         if (intent)
 797                 qcom_glink_advertise_intent(glink, channel, intent);
 798
 799         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 800 }
 801
 802 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 803 {
 804         struct glink_defer_cmd *dcmd;
 805
 806         extra = ALIGN(extra, 8);
 807
 808         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 809                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 810                 return -ENXIO;
 811         }
 812
 813         dcmd = kzalloc(struct_size(dcmd, data, extra), GFP_ATOMIC);
 814         if (!dcmd)
 815                 return -ENOMEM;
 816
 817         INIT_LIST_HEAD(&dcmd->node);
 818
 819         qcom_glink_rx_peek(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 820
 821         spin_lock(&glink->rx_lock);
 822         list_add_tail(&dcmd->node, &glink->rx_queue);
 823         spin_unlock(&glink->rx_lock);
 824
 825         schedule_work(&glink->rx_work);
 826         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 827
 828         return 0;
 829 }
 830
 831 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 832 {
 833         struct glink_core_rx_intent *intent;
 834         struct glink_channel *channel;
 835         struct {
 836                 struct glink_msg msg;
 837                 __le32 chunk_size;
 838                 __le32 left_size;
 839         } __packed hdr;
 840         unsigned int chunk_size;
 841         unsigned int left_size;
 842         unsigned int rcid;
 843         unsigned int liid;
 844         int ret = 0;
 845         unsigned long flags;
 846
 847         if (avail < sizeof(hdr)) {
 848                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 849                 return -EAGAIN;
 850         }
 851
 852         qcom_glink_rx_peek(glink, &hdr, 0, sizeof(hdr));
 853         chunk_size = le32_to_cpu(hdr.chunk_size);
 854         left_size = le32_to_cpu(hdr.left_size);
 855
 856         if (avail < sizeof(hdr) + chunk_size) {
 857                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 858                 return -EAGAIN;
 859         }
 860
 861         rcid = le16_to_cpu(hdr.msg.param1);
 862         spin_lock_irqsave(&glink->idr_lock, flags);
 863         channel = idr_find(&glink->rcids, rcid);
 864         spin_unlock_irqrestore(&glink->idr_lock, flags);
 865         if (!channel) {
 866                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 867
 868                 /* Drop the message */
 869                 goto advance_rx;
 870         }
 871
 872         if (glink->intentless) {
 873                 /* Might have an ongoing, fragmented, message to append */
 874                 if (!channel->buf) {
 875                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 876                         if (!intent)
 877                                 return -ENOMEM;
 878
 879                         intent->data = kmalloc(chunk_size + left_size,
 880                                                GFP_ATOMIC);
 881                         if (!intent->data) {
 882                                 kfree(intent);
 883                                 return -ENOMEM;
 884                         }
 885
 886                         intent->id = 0xbabababa;
 887                         intent->size = chunk_size + left_size;
 888                         intent->offset = 0;
 889
 890                         channel->buf = intent;
 891                 } else {
 892                         intent = channel->buf;
 893                 }
 894         } else {
 895                 liid = le32_to_cpu(hdr.msg.param2);
 896
 897                 spin_lock_irqsave(&channel->intent_lock, flags);
 898                 intent = idr_find(&channel->liids, liid);
 899                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 900
 901                 if (!intent) {
 902                         dev_err(glink->dev,
 903                                 "no intent found for channel %s intent %d",
 904                                 channel->name, liid);
 905                         ret = -ENOENT;
 906                         goto advance_rx;
 907                 }
 908         }
 909
 910         if (intent->size - intent->offset < chunk_size) {
 911                 dev_err(glink->dev, "Insufficient space in intent\n");
 912
 913                 /* The packet header lied, drop payload */
 914                 goto advance_rx;
 915         }
 916
 917         qcom_glink_rx_peek(glink, intent->data + intent->offset,
 918                            sizeof(hdr), chunk_size);
 919         intent->offset += chunk_size;
 920
 921         /* Handle message when no fragments remain to be received */
 922         if (!left_size) {
 923                 spin_lock(&channel->recv_lock);
 924                 if (channel->ept.cb) {
 925                         channel->ept.cb(channel->ept.rpdev,
 926                                         intent->data,
 927                                         intent->offset,
 928                                         channel->ept.priv,
 929                                         RPMSG_ADDR_ANY);
 930                 }
 931                 spin_unlock(&channel->recv_lock);
 932
 933                 intent->offset = 0;
 934                 channel->buf = NULL;
 935
 936                 qcom_glink_rx_done(glink, channel, intent);
 937         }
 938
 939 advance_rx:
 940         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 941
 942         return ret;
 943 }
 944
 945 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 946                                      unsigned int cid,
 947                                      unsigned int count,
 948                                      size_t avail)
 949 {
 950         struct glink_core_rx_intent *intent;
 951         struct glink_channel *channel;
 952         struct intent_pair {
 953                 __le32 size;
 954                 __le32 iid;
 955         };
 956
 957         struct {
 958                 struct glink_msg msg;
 959                 struct intent_pair intents[];
 960         } __packed * msg;
 961
 962         const size_t msglen = struct_size(msg, intents, count);
 963         int ret;
 964         int i;
 965         unsigned long flags;
 966
 967         if (avail < msglen) {
 968                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 969                 return;
 970         }
 971
 972         spin_lock_irqsave(&glink->idr_lock, flags);
 973         channel = idr_find(&glink->rcids, cid);
 974         spin_unlock_irqrestore(&glink->idr_lock, flags);
 975         if (!channel) {
 976                 dev_err(glink->dev, "intents for non-existing channel\n");
 977                 qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 978                 return;
 979         }
 980
 981         msg = kmalloc(msglen, GFP_ATOMIC);
 982         if (!msg)
 983                 return;
 984
 985         qcom_glink_rx_peek(glink, msg, 0, msglen);
 986
 987         for (i = 0; i < count; ++i) {
 988                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 989                 if (!intent)
 990                         break;
 991
 992                 intent->id = le32_to_cpu(msg->intents[i].iid);
 993                 intent->size = le32_to_cpu(msg->intents[i].size);
 994
 995                 spin_lock_irqsave(&channel->intent_lock, flags);
 996                 ret = idr_alloc(&channel->riids, intent,
 997                                 intent->id, intent->id + 1, GFP_ATOMIC);
 998                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 999
1000                 if (ret < 0)
1001                         dev_err(glink->dev, "failed to store remote intent\n");
1002         }
1003
1004         WRITE_ONCE(channel->intent_received, true);
1005         wake_up_all(&channel->intent_req_wq);
1006
1007         kfree(msg);
1008         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
1009 }
1010
1011 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
1012 {
1013         struct glink_channel *channel;
1014
1015         spin_lock(&glink->idr_lock);
1016         channel = idr_find(&glink->lcids, lcid);
1017         spin_unlock(&glink->idr_lock);
1018         if (!channel) {
1019                 dev_err(glink->dev, "Invalid open ack packet\n");
1020                 return -EINVAL;
1021         }
1022
1023         complete_all(&channel->open_ack);
1024
1025         return 0;
1026 }
1027
1028 void qcom_glink_native_rx(struct qcom_glink *glink)
1029 {
1030         struct glink_msg msg;
1031         unsigned int param1;
1032         unsigned int param2;
1033         unsigned int avail;
1034         unsigned int cmd;
1035         int ret = 0;
1036
1037         /* To wakeup any blocking writers */
1038         wake_up_all(&glink->tx_avail_notify);
1039
1040         for (;;) {
1041                 avail = qcom_glink_rx_avail(glink);
1042                 if (avail < sizeof(msg))
1043                         break;
1044
1045                 qcom_glink_rx_peek(glink, &msg, 0, sizeof(msg));
1046
1047                 cmd = le16_to_cpu(msg.cmd);
1048                 param1 = le16_to_cpu(msg.param1);
1049                 param2 = le32_to_cpu(msg.param2);
1050
1051                 switch (cmd) {
1052                 case GLINK_CMD_VERSION:
1053                 case GLINK_CMD_VERSION_ACK:
1054                 case GLINK_CMD_CLOSE:
1055                 case GLINK_CMD_CLOSE_ACK:
1056                 case GLINK_CMD_RX_INTENT_REQ:
1057                         ret = qcom_glink_rx_defer(glink, 0);
1058                         break;
1059                 case GLINK_CMD_OPEN_ACK:
1060                         ret = qcom_glink_rx_open_ack(glink, param1);
1061                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1062                         break;
1063                 case GLINK_CMD_OPEN:
1064                         ret = qcom_glink_rx_defer(glink, param2);
1065                         break;
1066                 case GLINK_CMD_TX_DATA:
1067                 case GLINK_CMD_TX_DATA_CONT:
1068                         ret = qcom_glink_rx_data(glink, avail);
1069                         break;
1070                 case GLINK_CMD_READ_NOTIF:
1071                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1072                         qcom_glink_tx_kick(glink);
1073                         break;
1074                 case GLINK_CMD_INTENT:
1075                         qcom_glink_handle_intent(glink, param1, param2, avail);
1076                         break;
1077                 case GLINK_CMD_RX_DONE:
1078                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1079                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1080                         break;
1081                 case GLINK_CMD_RX_DONE_W_REUSE:
1082                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1083                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1084                         break;
1085                 case GLINK_CMD_RX_INTENT_REQ_ACK:
1086                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1087                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1088                         break;
1089                 default:
1090                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1091                         ret = -EINVAL;
1092                         break;
1093                 }
1094
1095                 if (ret)
1096                         break;
1097         }
1098 }
1099 EXPORT_SYMBOL(qcom_glink_native_rx);
1100
1101 /* Locally initiated rpmsg_create_ept */
1102 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1103                                                      const char *name)
1104 {
1105         struct glink_channel *channel;
1106         int ret;
1107         unsigned long flags;
1108
1109         channel = qcom_glink_alloc_channel(glink, name);
1110         if (IS_ERR(channel))
1111                 return ERR_CAST(channel);
1112
1113         ret = qcom_glink_send_open_req(glink, channel);
1114         if (ret)
1115                 goto release_channel;
1116
1117         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1118         if (!ret)
1119                 goto err_timeout;
1120
1121         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1122         if (!ret)
1123                 goto err_timeout;
1124
1125         qcom_glink_send_open_ack(glink, channel);
1126
1127         return channel;
1128
1129 err_timeout:
1130         /* qcom_glink_send_open_req() did register the channel in lcids*/
1131         spin_lock_irqsave(&glink->idr_lock, flags);
1132         idr_remove(&glink->lcids, channel->lcid);
1133         spin_unlock_irqrestore(&glink->idr_lock, flags);
1134
1135 release_channel:
1136         /* Release qcom_glink_send_open_req() reference */
1137         kref_put(&channel->refcount, qcom_glink_channel_release);
1138         /* Release qcom_glink_alloc_channel() reference */
1139         kref_put(&channel->refcount, qcom_glink_channel_release);
1140
1141         return ERR_PTR(-ETIMEDOUT);
1142 }
1143
1144 /* Remote initiated rpmsg_create_ept */
1145 static int qcom_glink_create_remote(struct qcom_glink *glink,
1146                                     struct glink_channel *channel)
1147 {
1148         int ret;
1149
1150         qcom_glink_send_open_ack(glink, channel);
1151
1152         ret = qcom_glink_send_open_req(glink, channel);
1153         if (ret)
1154                 goto close_link;
1155
1156         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1157         if (!ret) {
1158                 ret = -ETIMEDOUT;
1159                 goto close_link;
1160         }
1161
1162         return 0;
1163
1164 close_link:
1165         /*
1166          * Send a close request to "undo" our open-ack. The close-ack will
1167          * release qcom_glink_send_open_req() reference and the last reference
1168          * will be relesed after receiving remote_close or transport unregister
1169          * by calling qcom_glink_native_remove().
1170          */
1171         qcom_glink_send_close_req(glink, channel);
1172
1173         return ret;
1174 }
1175
1176 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1177                                                     rpmsg_rx_cb_t cb,
1178                                                     void *priv,
1179                                                     struct rpmsg_channel_info
1180                                                                         chinfo)
1181 {
1182         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1183         struct glink_channel *channel;
1184         struct qcom_glink *glink = parent->glink;
1185         struct rpmsg_endpoint *ept;
1186         const char *name = chinfo.name;
1187         int cid;
1188         int ret;
1189         unsigned long flags;
1190
1191         spin_lock_irqsave(&glink->idr_lock, flags);
1192         idr_for_each_entry(&glink->rcids, channel, cid) {
1193                 if (!strcmp(channel->name, name))
1194                         break;
1195         }
1196         spin_unlock_irqrestore(&glink->idr_lock, flags);
1197
1198         if (!channel) {
1199                 channel = qcom_glink_create_local(glink, name);
1200                 if (IS_ERR(channel))
1201                         return NULL;
1202         } else {
1203                 ret = qcom_glink_create_remote(glink, channel);
1204                 if (ret)
1205                         return NULL;
1206         }
1207
1208         ept = &channel->ept;
1209         ept->rpdev = rpdev;
1210         ept->cb = cb;
1211         ept->priv = priv;
1212         ept->ops = &glink_endpoint_ops;
1213
1214         return ept;
1215 }
1216
1217 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1218 {
1219         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1220         struct device_node *np = rpdev->dev.of_node;
1221         struct qcom_glink *glink = channel->glink;
1222         struct glink_core_rx_intent *intent;
1223         const struct property *prop = NULL;
1224         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1225         int num_intents;
1226         int num_groups = 1;
1227         __be32 *val = defaults;
1228         int size;
1229
1230         if (glink->intentless || !completion_done(&channel->open_ack))
1231                 return 0;
1232
1233         prop = of_find_property(np, "qcom,intents", NULL);
1234         if (prop) {
1235                 val = prop->value;
1236                 num_groups = prop->length / sizeof(u32) / 2;
1237         }
1238
1239         /* Channel is now open, advertise base set of intents */
1240         while (num_groups--) {
1241                 size = be32_to_cpup(val++);
1242                 num_intents = be32_to_cpup(val++);
1243                 while (num_intents--) {
1244                         intent = qcom_glink_alloc_intent(glink, channel, size,
1245                                                          true);
1246                         if (!intent)
1247                                 break;
1248
1249                         qcom_glink_advertise_intent(glink, channel, intent);
1250                 }
1251         }
1252         return 0;
1253 }
1254
1255 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1256 {
1257         struct glink_channel *channel = to_glink_channel(ept);
1258         struct qcom_glink *glink = channel->glink;
1259         unsigned long flags;
1260
1261         spin_lock_irqsave(&channel->recv_lock, flags);
1262         channel->ept.cb = NULL;
1263         spin_unlock_irqrestore(&channel->recv_lock, flags);
1264
1265         /* Decouple the potential rpdev from the channel */
1266         channel->rpdev = NULL;
1267
1268         qcom_glink_send_close_req(glink, channel);
1269 }
1270
1271 static int qcom_glink_request_intent(struct qcom_glink *glink,
1272                                      struct glink_channel *channel,
1273                                      size_t size)
1274 {
1275         struct {
1276                 u16 id;
1277                 u16 cid;
1278                 u32 size;
1279         } __packed cmd;
1280
1281         int ret;
1282
1283         mutex_lock(&channel->intent_req_lock);
1284
1285         WRITE_ONCE(channel->intent_req_result, -1);
1286         WRITE_ONCE(channel->intent_received, false);
1287
1288         cmd.id = GLINK_CMD_RX_INTENT_REQ;
1289         cmd.cid = channel->lcid;
1290         cmd.size = size;
1291
1292         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1293         if (ret)
1294                 goto unlock;
1295
1296         ret = wait_event_timeout(channel->intent_req_wq,
1297                                  READ_ONCE(channel->intent_req_result) >= 0 &&
1298                                  READ_ONCE(channel->intent_received),
1299                                  10 * HZ);
1300         if (!ret) {
1301                 dev_err(glink->dev, "intent request timed out\n");
1302                 ret = -ETIMEDOUT;
1303         } else {
1304                 ret = READ_ONCE(channel->intent_req_result) ? 0 : -ECANCELED;
1305         }
1306
1307 unlock:
1308         mutex_unlock(&channel->intent_req_lock);
1309         return ret;
1310 }
1311
1312 static int __qcom_glink_send(struct glink_channel *channel,
1313                              void *data, int len, bool wait)
1314 {
1315         struct qcom_glink *glink = channel->glink;
1316         struct glink_core_rx_intent *intent = NULL;
1317         struct glink_core_rx_intent *tmp;
1318         int iid = 0;
1319         struct {
1320                 struct glink_msg msg;
1321                 __le32 chunk_size;
1322                 __le32 left_size;
1323         } __packed req;
1324         int ret;
1325         unsigned long flags;
1326         int chunk_size = len;
1327         size_t offset = 0;
1328
1329         if (!glink->intentless) {
1330                 while (!intent) {
1331                         spin_lock_irqsave(&channel->intent_lock, flags);
1332                         idr_for_each_entry(&channel->riids, tmp, iid) {
1333                                 if (tmp->size >= len && !tmp->in_use) {
1334                                         if (!intent)
1335                                                 intent = tmp;
1336                                         else if (intent->size > tmp->size)
1337                                                 intent = tmp;
1338                                         if (intent->size == len)
1339                                                 break;
1340                                 }
1341                         }
1342                         if (intent)
1343                                 intent->in_use = true;
1344                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1345
1346                         /* We found an available intent */
1347                         if (intent)
1348                                 break;
1349
1350                         if (!wait)
1351                                 return -EBUSY;
1352
1353                         ret = qcom_glink_request_intent(glink, channel, len);
1354                         if (ret < 0)
1355                                 return ret;
1356                 }
1357
1358                 iid = intent->id;
1359         }
1360
1361         while (offset < len) {
1362                 chunk_size = len - offset;
1363                 if (chunk_size > SZ_8K && wait)
1364                         chunk_size = SZ_8K;
1365
1366                 req.msg.cmd = cpu_to_le16(offset == 0 ? GLINK_CMD_TX_DATA : GLINK_CMD_TX_DATA_CONT);
1367                 req.msg.param1 = cpu_to_le16(channel->lcid);
1368                 req.msg.param2 = cpu_to_le32(iid);
1369                 req.chunk_size = cpu_to_le32(chunk_size);
1370                 req.left_size = cpu_to_le32(len - offset - chunk_size);
1371
1372                 ret = qcom_glink_tx(glink, &req, sizeof(req), data + offset, chunk_size, wait);
1373                 if (ret) {
1374                         /* Mark intent available if we failed */
1375                         if (intent)
1376                                 intent->in_use = false;
1377                         return ret;
1378                 }
1379
1380                 offset += chunk_size;
1381         }
1382
1383         return 0;
1384 }
1385
1386 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1387 {
1388         struct glink_channel *channel = to_glink_channel(ept);
1389
1390         return __qcom_glink_send(channel, data, len, true);
1391 }
1392
1393 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1394 {
1395         struct glink_channel *channel = to_glink_channel(ept);
1396
1397         return __qcom_glink_send(channel, data, len, false);
1398 }
1399
1400 static int qcom_glink_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1401 {
1402         struct glink_channel *channel = to_glink_channel(ept);
1403
1404         return __qcom_glink_send(channel, data, len, true);
1405 }
1406
1407 static int qcom_glink_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1408 {
1409         struct glink_channel *channel = to_glink_channel(ept);
1410
1411         return __qcom_glink_send(channel, data, len, false);
1412 }
1413
1414 /*
1415  * Finds the device_node for the glink child interested in this channel.
1416  */
1417 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1418                                                     const char *channel)
1419 {
1420         struct device_node *child;
1421         const char *name;
1422         const char *key;
1423         int ret;
1424
1425         for_each_available_child_of_node(node, child) {
1426                 key = "qcom,glink-channels";
1427                 ret = of_property_read_string(child, key, &name);
1428                 if (ret)
1429                         continue;
1430
1431                 if (strcmp(name, channel) == 0)
1432                         return child;
1433         }
1434
1435         return NULL;
1436 }
1437
1438 static const struct rpmsg_device_ops glink_device_ops = {
1439         .create_ept = qcom_glink_create_ept,
1440         .announce_create = qcom_glink_announce_create,
1441 };
1442
1443 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1444         .destroy_ept = qcom_glink_destroy_ept,
1445         .send = qcom_glink_send,
1446         .sendto = qcom_glink_sendto,
1447         .trysend = qcom_glink_trysend,
1448         .trysendto = qcom_glink_trysendto,
1449 };
1450
1451 static void qcom_glink_rpdev_release(struct device *dev)
1452 {
1453         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1454
1455         kfree(rpdev->driver_override);
1456         kfree(rpdev);
1457 }
1458
1459 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1460                               char *name)
1461 {
1462         struct glink_channel *channel;
1463         struct rpmsg_device *rpdev;
1464         bool create_device = false;
1465         struct device_node *node;
1466         int lcid;
1467         int ret;
1468         unsigned long flags;
1469
1470         spin_lock_irqsave(&glink->idr_lock, flags);
1471         idr_for_each_entry(&glink->lcids, channel, lcid) {
1472                 if (!strcmp(channel->name, name))
1473                         break;
1474         }
1475         spin_unlock_irqrestore(&glink->idr_lock, flags);
1476
1477         if (!channel) {
1478                 channel = qcom_glink_alloc_channel(glink, name);
1479                 if (IS_ERR(channel))
1480                         return PTR_ERR(channel);
1481
1482                 /* The opening dance was initiated by the remote */
1483                 create_device = true;
1484         }
1485
1486         spin_lock_irqsave(&glink->idr_lock, flags);
1487         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1488         if (ret < 0) {
1489                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1490                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1491                 goto free_channel;
1492         }
1493         channel->rcid = ret;
1494         spin_unlock_irqrestore(&glink->idr_lock, flags);
1495
1496         complete_all(&channel->open_req);
1497
1498         if (create_device) {
1499                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1500                 if (!rpdev) {
1501                         ret = -ENOMEM;
1502                         goto rcid_remove;
1503                 }
1504
1505                 rpdev->ept = &channel->ept;
1506                 strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE);
1507                 rpdev->src = RPMSG_ADDR_ANY;
1508                 rpdev->dst = RPMSG_ADDR_ANY;
1509                 rpdev->ops = &glink_device_ops;
1510
1511                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1512                 rpdev->dev.of_node = node;
1513                 rpdev->dev.parent = glink->dev;
1514                 rpdev->dev.release = qcom_glink_rpdev_release;
1515
1516                 ret = rpmsg_register_device(rpdev);
1517                 if (ret)
1518                         goto rcid_remove;
1519
1520                 channel->rpdev = rpdev;
1521         }
1522
1523         return 0;
1524
1525 rcid_remove:
1526         spin_lock_irqsave(&glink->idr_lock, flags);
1527         idr_remove(&glink->rcids, channel->rcid);
1528         channel->rcid = 0;
1529         spin_unlock_irqrestore(&glink->idr_lock, flags);
1530 free_channel:
1531         /* Release the reference, iff we took it */
1532         if (create_device)
1533                 kref_put(&channel->refcount, qcom_glink_channel_release);
1534
1535         return ret;
1536 }
1537
1538 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1539 {
1540         struct rpmsg_channel_info chinfo;
1541         struct glink_channel *channel;
1542         unsigned long flags;
1543
1544         spin_lock_irqsave(&glink->idr_lock, flags);
1545         channel = idr_find(&glink->rcids, rcid);
1546         spin_unlock_irqrestore(&glink->idr_lock, flags);
1547         if (WARN(!channel, "close request on unknown channel\n"))
1548                 return;
1549
1550         /* cancel pending rx_done work */
1551         cancel_work_sync(&channel->intent_work);
1552
1553         if (channel->rpdev) {
1554                 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1555                 chinfo.src = RPMSG_ADDR_ANY;
1556                 chinfo.dst = RPMSG_ADDR_ANY;
1557
1558                 rpmsg_unregister_device(glink->dev, &chinfo);
1559         }
1560         channel->rpdev = NULL;
1561
1562         qcom_glink_send_close_ack(glink, channel->rcid);
1563
1564         spin_lock_irqsave(&glink->idr_lock, flags);
1565         idr_remove(&glink->rcids, channel->rcid);
1566         channel->rcid = 0;
1567         spin_unlock_irqrestore(&glink->idr_lock, flags);
1568
1569         kref_put(&channel->refcount, qcom_glink_channel_release);
1570 }
1571
1572 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1573 {
1574         struct rpmsg_channel_info chinfo;
1575         struct glink_channel *channel;
1576         unsigned long flags;
1577
1578         /* To wakeup any blocking writers */
1579         wake_up_all(&glink->tx_avail_notify);
1580
1581         spin_lock_irqsave(&glink->idr_lock, flags);
1582         channel = idr_find(&glink->lcids, lcid);
1583         if (WARN(!channel, "close ack on unknown channel\n")) {
1584                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1585                 return;
1586         }
1587
1588         idr_remove(&glink->lcids, channel->lcid);
1589         channel->lcid = 0;
1590         spin_unlock_irqrestore(&glink->idr_lock, flags);
1591
1592         /* Decouple the potential rpdev from the channel */
1593         if (channel->rpdev) {
1594                 strscpy(chinfo.name, channel->name, sizeof(chinfo.name));
1595                 chinfo.src = RPMSG_ADDR_ANY;
1596                 chinfo.dst = RPMSG_ADDR_ANY;
1597
1598                 rpmsg_unregister_device(glink->dev, &chinfo);
1599         }
1600         channel->rpdev = NULL;
1601
1602         kref_put(&channel->refcount, qcom_glink_channel_release);
1603 }
1604
1605 static void qcom_glink_work(struct work_struct *work)
1606 {
1607         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1608                                                 rx_work);
1609         struct glink_defer_cmd *dcmd;
1610         struct glink_msg *msg;
1611         unsigned long flags;
1612         unsigned int param1;
1613         unsigned int param2;
1614         unsigned int cmd;
1615
1616         for (;;) {
1617                 spin_lock_irqsave(&glink->rx_lock, flags);
1618                 if (list_empty(&glink->rx_queue)) {
1619                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1620                         break;
1621                 }
1622                 dcmd = list_first_entry(&glink->rx_queue,
1623                                         struct glink_defer_cmd, node);
1624                 list_del(&dcmd->node);
1625                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1626
1627                 msg = &dcmd->msg;
1628                 cmd = le16_to_cpu(msg->cmd);
1629                 param1 = le16_to_cpu(msg->param1);
1630                 param2 = le32_to_cpu(msg->param2);
1631
1632                 switch (cmd) {
1633                 case GLINK_CMD_VERSION:
1634                         qcom_glink_receive_version(glink, param1, param2);
1635                         break;
1636                 case GLINK_CMD_VERSION_ACK:
1637                         qcom_glink_receive_version_ack(glink, param1, param2);
1638                         break;
1639                 case GLINK_CMD_OPEN:
1640                         qcom_glink_rx_open(glink, param1, msg->data);
1641                         break;
1642                 case GLINK_CMD_CLOSE:
1643                         qcom_glink_rx_close(glink, param1);
1644                         break;
1645                 case GLINK_CMD_CLOSE_ACK:
1646                         qcom_glink_rx_close_ack(glink, param1);
1647                         break;
1648                 case GLINK_CMD_RX_INTENT_REQ:
1649                         qcom_glink_handle_intent_req(glink, param1, param2);
1650                         break;
1651                 default:
1652                         WARN(1, "Unknown defer object %d\n", cmd);
1653                         break;
1654                 }
1655
1656                 kfree(dcmd);
1657         }
1658 }
1659
1660 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1661 {
1662         struct glink_defer_cmd *dcmd;
1663         struct glink_defer_cmd *tmp;
1664
1665         /* cancel any pending deferred rx_work */
1666         cancel_work_sync(&glink->rx_work);
1667
1668         list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1669                 kfree(dcmd);
1670 }
1671
1672 static ssize_t rpmsg_name_show(struct device *dev,
1673                                struct device_attribute *attr, char *buf)
1674 {
1675         int ret = 0;
1676         const char *name;
1677
1678         ret = of_property_read_string(dev->of_node, "label", &name);
1679         if (ret < 0)
1680                 name = dev->of_node->name;
1681
1682         return sysfs_emit(buf, "%s\n", name);
1683 }
1684 static DEVICE_ATTR_RO(rpmsg_name);
1685
1686 static struct attribute *qcom_glink_attrs[] = {
1687         &dev_attr_rpmsg_name.attr,
1688         NULL
1689 };
1690 ATTRIBUTE_GROUPS(qcom_glink);
1691
1692 static void qcom_glink_device_release(struct device *dev)
1693 {
1694         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1695         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1696
1697         /* Release qcom_glink_alloc_channel() reference */
1698         kref_put(&channel->refcount, qcom_glink_channel_release);
1699         kfree(rpdev->driver_override);
1700         kfree(rpdev);
1701 }
1702
1703 static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1704 {
1705         struct rpmsg_device *rpdev;
1706         struct glink_channel *channel;
1707
1708         rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1709         if (!rpdev)
1710                 return -ENOMEM;
1711
1712         channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1713         if (IS_ERR(channel)) {
1714                 kfree(rpdev);
1715                 return PTR_ERR(channel);
1716         }
1717         channel->rpdev = rpdev;
1718
1719         rpdev->ept = &channel->ept;
1720         rpdev->ops = &glink_device_ops;
1721         rpdev->dev.parent = glink->dev;
1722         rpdev->dev.release = qcom_glink_device_release;
1723
1724         return rpmsg_ctrldev_register_device(rpdev);
1725 }
1726
1727 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1728                                            unsigned long features,
1729                                            struct qcom_glink_pipe *rx,
1730                                            struct qcom_glink_pipe *tx,
1731                                            bool intentless)
1732 {
1733         int ret;
1734         struct qcom_glink *glink;
1735
1736         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1737         if (!glink)
1738                 return ERR_PTR(-ENOMEM);
1739
1740         glink->dev = dev;
1741         glink->tx_pipe = tx;
1742         glink->rx_pipe = rx;
1743
1744         glink->features = features;
1745         glink->intentless = intentless;
1746
1747         spin_lock_init(&glink->tx_lock);
1748         spin_lock_init(&glink->rx_lock);
1749         INIT_LIST_HEAD(&glink->rx_queue);
1750         INIT_WORK(&glink->rx_work, qcom_glink_work);
1751         init_waitqueue_head(&glink->tx_avail_notify);
1752
1753         spin_lock_init(&glink->idr_lock);
1754         idr_init(&glink->lcids);
1755         idr_init(&glink->rcids);
1756
1757         glink->dev->groups = qcom_glink_groups;
1758
1759         ret = device_add_groups(dev, qcom_glink_groups);
1760         if (ret)
1761                 dev_err(dev, "failed to add groups\n");
1762
1763         ret = qcom_glink_send_version(glink);
1764         if (ret)
1765                 return ERR_PTR(ret);
1766
1767         ret = qcom_glink_create_chrdev(glink);
1768         if (ret)
1769                 dev_err(glink->dev, "failed to register chrdev\n");
1770
1771         return glink;
1772 }
1773 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1774
1775 static int qcom_glink_remove_device(struct device *dev, void *data)
1776 {
1777         device_unregister(dev);
1778
1779         return 0;
1780 }
1781
1782 void qcom_glink_native_remove(struct qcom_glink *glink)
1783 {
1784         struct glink_channel *channel;
1785         unsigned long flags;
1786         int cid;
1787         int ret;
1788
1789         qcom_glink_cancel_rx_work(glink);
1790
1791         /* Fail all attempts at sending messages */
1792         spin_lock_irqsave(&glink->tx_lock, flags);
1793         glink->abort_tx = true;
1794         wake_up_all(&glink->tx_avail_notify);
1795         spin_unlock_irqrestore(&glink->tx_lock, flags);
1796
1797         /* Abort any senders waiting for intent requests */
1798         spin_lock_irqsave(&glink->idr_lock, flags);
1799         idr_for_each_entry(&glink->lcids, channel, cid)
1800                 qcom_glink_intent_req_abort(channel);
1801         spin_unlock_irqrestore(&glink->idr_lock, flags);
1802
1803         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1804         if (ret)
1805                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1806
1807         /* Release any defunct local channels, waiting for close-ack */
1808         idr_for_each_entry(&glink->lcids, channel, cid)
1809                 kref_put(&channel->refcount, qcom_glink_channel_release);
1810
1811         /* Release any defunct local channels, waiting for close-req */
1812         idr_for_each_entry(&glink->rcids, channel, cid)
1813                 kref_put(&channel->refcount, qcom_glink_channel_release);
1814
1815         idr_destroy(&glink->lcids);
1816         idr_destroy(&glink->rcids);
1817 }
1818 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1819
1820 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1821 MODULE_LICENSE("GPL v2");