drivers/rpmsg/qcom_glink_native.c

   1 /*
   2  * Copyright (c) 2016-2017, Linaro Ltd
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/idr.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/list.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_irq.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regmap.h>
  25 #include <linux/rpmsg.h>
  26 #include <linux/sizes.h>
  27 #include <linux/slab.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/mailbox_client.h>
  30
  31 #include "rpmsg_internal.h"
  32 #include "qcom_glink_native.h"
  33
  34 #define GLINK_NAME_SIZE         32
  35 #define GLINK_VERSION_1         1
  36
  37 #define RPM_GLINK_CID_MIN       1
  38 #define RPM_GLINK_CID_MAX       65536
  39
  40 struct glink_msg {
  41         __le16 cmd;
  42         __le16 param1;
  43         __le32 param2;
  44         u8 data[];
  45 } __packed;
  46
  47 /**
  48  * struct glink_defer_cmd - deferred incoming control message
  49  * @node:       list node
  50  * @msg:        message header
  51  * data:        payload of the message
  52  *
  53  * Copy of a received control message, to be added to @rx_queue and processed
  54  * by @rx_work of @qcom_glink.
  55  */
  56 struct glink_defer_cmd {
  57         struct list_head node;
  58
  59         struct glink_msg msg;
  60         u8 data[];
  61 };
  62
  63 /**
  64  * struct glink_core_rx_intent - RX intent
  65  * RX intent
  66  *
  67  * data: pointer to the data (may be NULL for zero-copy)
  68  * id: remote or local intent ID
  69  * size: size of the original intent (do not modify)
  70  * reuse: To mark if the intent can be reused after first use
  71  * in_use: To mark if intent is already in use for the channel
  72  * offset: next write offset (initially 0)
  73  */
  74 struct glink_core_rx_intent {
  75         void *data;
  76         u32 id;
  77         size_t size;
  78         bool reuse;
  79         bool in_use;
  80         u32 offset;
  81
  82         struct list_head node;
  83 };
  84
  85 /**
  86  * struct qcom_glink - driver context, relates to one remote subsystem
  87  * @dev:        reference to the associated struct device
  88  * @mbox_client: mailbox client
  89  * @mbox_chan:  mailbox channel
  90  * @rx_pipe:    pipe object for receive FIFO
  91  * @tx_pipe:    pipe object for transmit FIFO
  92  * @irq:        IRQ for signaling incoming events
  93  * @rx_work:    worker for handling received control messages
  94  * @rx_lock:    protects the @rx_queue
  95  * @rx_queue:   queue of received control messages to be processed in @rx_work
  96  * @tx_lock:    synchronizes operations on the tx fifo
  97  * @idr_lock:   synchronizes @lcids and @rcids modifications
  98  * @lcids:      idr of all channels with a known local channel id
  99  * @rcids:      idr of all channels with a known remote channel id
 100  */
 101 struct qcom_glink {
 102         struct device *dev;
 103
 104         struct mbox_client mbox_client;
 105         struct mbox_chan *mbox_chan;
 106
 107         struct qcom_glink_pipe *rx_pipe;
 108         struct qcom_glink_pipe *tx_pipe;
 109
 110         int irq;
 111
 112         struct work_struct rx_work;
 113         spinlock_t rx_lock;
 114         struct list_head rx_queue;
 115
 116         struct mutex tx_lock;
 117
 118         spinlock_t idr_lock;
 119         struct idr lcids;
 120         struct idr rcids;
 121         unsigned long features;
 122
 123         bool intentless;
 124 };
 125
 126 enum {
 127         GLINK_STATE_CLOSED,
 128         GLINK_STATE_OPENING,
 129         GLINK_STATE_OPEN,
 130         GLINK_STATE_CLOSING,
 131 };
 132
 133 /**
 134  * struct glink_channel - internal representation of a channel
 135  * @rpdev:      rpdev reference, only used for primary endpoints
 136  * @ept:        rpmsg endpoint this channel is associated with
 137  * @glink:      qcom_glink context handle
 138  * @refcount:   refcount for the channel object
 139  * @recv_lock:  guard for @ept.cb
 140  * @name:       unique channel name/identifier
 141  * @lcid:       channel id, in local space
 142  * @rcid:       channel id, in remote space
 143  * @intent_lock: lock for protection of @liids, @riids
 144  * @liids:      idr of all local intents
 145  * @riids:      idr of all remote intents
 146  * @intent_work: worker responsible for transmitting rx_done packets
 147  * @done_intents: list of intents that needs to be announced rx_done
 148  * @buf:        receive buffer, for gathering fragments
 149  * @buf_offset: write offset in @buf
 150  * @buf_size:   size of current @buf
 151  * @open_ack:   completed once remote has acked the open-request
 152  * @open_req:   completed once open-request has been received
 153  * @intent_req_lock: Synchronises multiple intent requests
 154  * @intent_req_result: Result of intent request
 155  * @intent_req_comp: Completion for intent_req signalling
 156  */
 157 struct glink_channel {
 158         struct rpmsg_endpoint ept;
 159
 160         struct rpmsg_device *rpdev;
 161         struct qcom_glink *glink;
 162
 163         struct kref refcount;
 164
 165         spinlock_t recv_lock;
 166
 167         char *name;
 168         unsigned int lcid;
 169         unsigned int rcid;
 170
 171         spinlock_t intent_lock;
 172         struct idr liids;
 173         struct idr riids;
 174         struct work_struct intent_work;
 175         struct list_head done_intents;
 176
 177         struct glink_core_rx_intent *buf;
 178         int buf_offset;
 179         int buf_size;
 180
 181         struct completion open_ack;
 182         struct completion open_req;
 183
 184         struct mutex intent_req_lock;
 185         bool intent_req_result;
 186         struct completion intent_req_comp;
 187 };
 188
 189 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 190
 191 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 192
 193 #define RPM_CMD_VERSION                 0
 194 #define RPM_CMD_VERSION_ACK             1
 195 #define RPM_CMD_OPEN                    2
 196 #define RPM_CMD_CLOSE                   3
 197 #define RPM_CMD_OPEN_ACK                4
 198 #define RPM_CMD_INTENT                  5
 199 #define RPM_CMD_RX_DONE                 6
 200 #define RPM_CMD_RX_INTENT_REQ           7
 201 #define RPM_CMD_RX_INTENT_REQ_ACK       8
 202 #define RPM_CMD_TX_DATA                 9
 203 #define RPM_CMD_CLOSE_ACK               11
 204 #define RPM_CMD_TX_DATA_CONT            12
 205 #define RPM_CMD_READ_NOTIF              13
 206 #define RPM_CMD_RX_DONE_W_REUSE         14
 207
 208 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 209
 210 static void qcom_glink_rx_done_work(struct work_struct *work);
 211
 212 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 213                                                       const char *name)
 214 {
 215         struct glink_channel *channel;
 216
 217         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 218         if (!channel)
 219                 return ERR_PTR(-ENOMEM);
 220
 221         /* Setup glink internal glink_channel data */
 222         spin_lock_init(&channel->recv_lock);
 223         spin_lock_init(&channel->intent_lock);
 224         mutex_init(&channel->intent_req_lock);
 225
 226         channel->glink = glink;
 227         channel->name = kstrdup(name, GFP_KERNEL);
 228         if (!channel->name) {
 229                 kfree(channel);
 230                 return ERR_PTR(-ENOMEM);
 231         }
 232
 233         init_completion(&channel->open_req);
 234         init_completion(&channel->open_ack);
 235         init_completion(&channel->intent_req_comp);
 236
 237         INIT_LIST_HEAD(&channel->done_intents);
 238         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 239
 240         idr_init(&channel->liids);
 241         idr_init(&channel->riids);
 242         kref_init(&channel->refcount);
 243
 244         return channel;
 245 }
 246
 247 static void qcom_glink_channel_release(struct kref *ref)
 248 {
 249         struct glink_channel *channel = container_of(ref, struct glink_channel,
 250                                                      refcount);
 251         struct glink_core_rx_intent *intent;
 252         struct glink_core_rx_intent *tmp;
 253         unsigned long flags;
 254         int iid;
 255
 256         /* cancel pending rx_done work */
 257         cancel_work_sync(&channel->intent_work);
 258
 259         spin_lock_irqsave(&channel->intent_lock, flags);
 260         /* Free all non-reuse intents pending rx_done work */
 261         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 262                 if (!intent->reuse) {
 263                         kfree(intent->data);
 264                         kfree(intent);
 265                 }
 266         }
 267
 268         idr_for_each_entry(&channel->liids, tmp, iid) {
 269                 kfree(tmp->data);
 270                 kfree(tmp);
 271         }
 272         idr_destroy(&channel->liids);
 273
 274         idr_for_each_entry(&channel->riids, tmp, iid)
 275                 kfree(tmp);
 276         idr_destroy(&channel->riids);
 277         spin_unlock_irqrestore(&channel->intent_lock, flags);
 278
 279         kfree(channel->name);
 280         kfree(channel);
 281 }
 282
 283 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 284 {
 285         return glink->rx_pipe->avail(glink->rx_pipe);
 286 }
 287
 288 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 289                                void *data, unsigned int offset, size_t count)
 290 {
 291         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 292 }
 293
 294 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 295 {
 296         glink->rx_pipe->advance(glink->rx_pipe, count);
 297 }
 298
 299 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 300 {
 301         return glink->tx_pipe->avail(glink->tx_pipe);
 302 }
 303
 304 static void qcom_glink_tx_write(struct qcom_glink *glink,
 305                                 const void *hdr, size_t hlen,
 306                                 const void *data, size_t dlen)
 307 {
 308         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 309 }
 310
 311 static int qcom_glink_tx(struct qcom_glink *glink,
 312                          const void *hdr, size_t hlen,
 313                          const void *data, size_t dlen, bool wait)
 314 {
 315         unsigned int tlen = hlen + dlen;
 316         int ret;
 317
 318         /* Reject packets that are too big */
 319         if (tlen >= glink->tx_pipe->length)
 320                 return -EINVAL;
 321
 322         ret = mutex_lock_interruptible(&glink->tx_lock);
 323         if (ret)
 324                 return ret;
 325
 326         while (qcom_glink_tx_avail(glink) < tlen) {
 327                 if (!wait) {
 328                         ret = -EAGAIN;
 329                         goto out;
 330                 }
 331
 332                 usleep_range(10000, 15000);
 333         }
 334
 335         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 336
 337         mbox_send_message(glink->mbox_chan, NULL);
 338         mbox_client_txdone(glink->mbox_chan, 0);
 339
 340 out:
 341         mutex_unlock(&glink->tx_lock);
 342
 343         return ret;
 344 }
 345
 346 static int qcom_glink_send_version(struct qcom_glink *glink)
 347 {
 348         struct glink_msg msg;
 349
 350         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 351         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 352         msg.param2 = cpu_to_le32(glink->features);
 353
 354         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 355 }
 356
 357 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 358 {
 359         struct glink_msg msg;
 360
 361         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 362         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 363         msg.param2 = cpu_to_le32(glink->features);
 364
 365         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 366 }
 367
 368 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 369                                      struct glink_channel *channel)
 370 {
 371         struct glink_msg msg;
 372
 373         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 374         msg.param1 = cpu_to_le16(channel->rcid);
 375         msg.param2 = cpu_to_le32(0);
 376
 377         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 378 }
 379
 380 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 381                                              unsigned int cid, bool granted)
 382 {
 383         struct glink_channel *channel;
 384         unsigned long flags;
 385
 386         spin_lock_irqsave(&glink->idr_lock, flags);
 387         channel = idr_find(&glink->rcids, cid);
 388         spin_unlock_irqrestore(&glink->idr_lock, flags);
 389         if (!channel) {
 390                 dev_err(glink->dev, "unable to find channel\n");
 391                 return;
 392         }
 393
 394         channel->intent_req_result = granted;
 395         complete(&channel->intent_req_comp);
 396 }
 397
 398 /**
 399  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 400  * @glink: Ptr to the glink edge
 401  * @channel: Ptr to the channel that the open req is sent
 402  *
 403  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 404  * Will return with refcount held, regardless of outcome.
 405  *
 406  * Returns 0 on success, negative errno otherwise.
 407  */
 408 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 409                                     struct glink_channel *channel)
 410 {
 411         struct {
 412                 struct glink_msg msg;
 413                 u8 name[GLINK_NAME_SIZE];
 414         } __packed req;
 415         int name_len = strlen(channel->name) + 1;
 416         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 417         int ret;
 418         unsigned long flags;
 419
 420         kref_get(&channel->refcount);
 421
 422         spin_lock_irqsave(&glink->idr_lock, flags);
 423         ret = idr_alloc_cyclic(&glink->lcids, channel,
 424                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 425                                GFP_ATOMIC);
 426         spin_unlock_irqrestore(&glink->idr_lock, flags);
 427         if (ret < 0)
 428                 return ret;
 429
 430         channel->lcid = ret;
 431
 432         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 433         req.msg.param1 = cpu_to_le16(channel->lcid);
 434         req.msg.param2 = cpu_to_le32(name_len);
 435         strcpy(req.name, channel->name);
 436
 437         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 438         if (ret)
 439                 goto remove_idr;
 440
 441         return 0;
 442
 443 remove_idr:
 444         spin_lock_irqsave(&glink->idr_lock, flags);
 445         idr_remove(&glink->lcids, channel->lcid);
 446         channel->lcid = 0;
 447         spin_unlock_irqrestore(&glink->idr_lock, flags);
 448
 449         return ret;
 450 }
 451
 452 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 453                                       struct glink_channel *channel)
 454 {
 455         struct glink_msg req;
 456
 457         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 458         req.param1 = cpu_to_le16(channel->lcid);
 459         req.param2 = 0;
 460
 461         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 462 }
 463
 464 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 465                                       unsigned int rcid)
 466 {
 467         struct glink_msg req;
 468
 469         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 470         req.param1 = cpu_to_le16(rcid);
 471         req.param2 = 0;
 472
 473         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 474 }
 475
 476 static void qcom_glink_rx_done_work(struct work_struct *work)
 477 {
 478         struct glink_channel *channel = container_of(work, struct glink_channel,
 479                                                      intent_work);
 480         struct qcom_glink *glink = channel->glink;
 481         struct glink_core_rx_intent *intent, *tmp;
 482         struct {
 483                 u16 id;
 484                 u16 lcid;
 485                 u32 liid;
 486         } __packed cmd;
 487
 488         unsigned int cid = channel->lcid;
 489         unsigned int iid;
 490         bool reuse;
 491         unsigned long flags;
 492
 493         spin_lock_irqsave(&channel->intent_lock, flags);
 494         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 495                 list_del(&intent->node);
 496                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 497                 iid = intent->id;
 498                 reuse = intent->reuse;
 499
 500                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 501                 cmd.lcid = cid;
 502                 cmd.liid = iid;
 503
 504                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 505                 if (!reuse) {
 506                         kfree(intent->data);
 507                         kfree(intent);
 508                 }
 509                 spin_lock_irqsave(&channel->intent_lock, flags);
 510         }
 511         spin_unlock_irqrestore(&channel->intent_lock, flags);
 512 }
 513
 514 static void qcom_glink_rx_done(struct qcom_glink *glink,
 515                                struct glink_channel *channel,
 516                                struct glink_core_rx_intent *intent)
 517 {
 518         /* We don't send RX_DONE to intentless systems */
 519         if (glink->intentless) {
 520                 kfree(intent->data);
 521                 kfree(intent);
 522                 return;
 523         }
 524
 525         /* Take it off the tree of receive intents */
 526         if (!intent->reuse) {
 527                 spin_lock(&channel->intent_lock);
 528                 idr_remove(&channel->liids, intent->id);
 529                 spin_unlock(&channel->intent_lock);
 530         }
 531
 532         /* Schedule the sending of a rx_done indication */
 533         spin_lock(&channel->intent_lock);
 534         list_add_tail(&intent->node, &channel->done_intents);
 535         spin_unlock(&channel->intent_lock);
 536
 537         schedule_work(&channel->intent_work);
 538 }
 539
 540 /**
 541  * qcom_glink_receive_version() - receive version/features from remote system
 542  *
 543  * @glink:      pointer to transport interface
 544  * @r_version:  remote version
 545  * @r_features: remote features
 546  *
 547  * This function is called in response to a remote-initiated version/feature
 548  * negotiation sequence.
 549  */
 550 static void qcom_glink_receive_version(struct qcom_glink *glink,
 551                                        u32 version,
 552                                        u32 features)
 553 {
 554         switch (version) {
 555         case 0:
 556                 break;
 557         case GLINK_VERSION_1:
 558                 glink->features &= features;
 559                 /* FALLTHROUGH */
 560         default:
 561                 qcom_glink_send_version_ack(glink);
 562                 break;
 563         }
 564 }
 565
 566 /**
 567  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 568  *
 569  * @glink:      pointer to transport interface
 570  * @r_version:  remote version response
 571  * @r_features: remote features response
 572  *
 573  * This function is called in response to a local-initiated version/feature
 574  * negotiation sequence and is the counter-offer from the remote side based
 575  * upon the initial version and feature set requested.
 576  */
 577 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 578                                            u32 version,
 579                                            u32 features)
 580 {
 581         switch (version) {
 582         case 0:
 583                 /* Version negotiation failed */
 584                 break;
 585         case GLINK_VERSION_1:
 586                 if (features == glink->features)
 587                         break;
 588
 589                 glink->features &= features;
 590                 /* FALLTHROUGH */
 591         default:
 592                 qcom_glink_send_version(glink);
 593                 break;
 594         }
 595 }
 596
 597 /**
 598  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 599                                       wire format and transmit
 600  * @glink:      The transport to transmit on.
 601  * @channel:    The glink channel
 602  * @granted:    The request response to encode.
 603  *
 604  * Return: 0 on success or standard Linux error code.
 605  */
 606 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 607                                           struct glink_channel *channel,
 608                                           bool granted)
 609 {
 610         struct glink_msg msg;
 611
 612         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 613         msg.param1 = cpu_to_le16(channel->lcid);
 614         msg.param2 = cpu_to_le32(granted);
 615
 616         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 617
 618         return 0;
 619 }
 620
 621 /**
 622  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 623  *                         transmit
 624  * @glink:      The transport to transmit on.
 625  * @channel:    The local channel
 626  * @size:       The intent to pass on to remote.
 627  *
 628  * Return: 0 on success or standard Linux error code.
 629  */
 630 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 631                                        struct glink_channel *channel,
 632                                        struct glink_core_rx_intent *intent)
 633 {
 634         struct command {
 635                 u16 id;
 636                 u16 lcid;
 637                 u32 count;
 638                 u32 size;
 639                 u32 liid;
 640         } __packed;
 641         struct command cmd;
 642
 643         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 644         cmd.lcid = cpu_to_le16(channel->lcid);
 645         cmd.count = cpu_to_le32(1);
 646         cmd.size = cpu_to_le32(intent->size);
 647         cmd.liid = cpu_to_le32(intent->id);
 648
 649         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 650
 651         return 0;
 652 }
 653
 654 static struct glink_core_rx_intent *
 655 qcom_glink_alloc_intent(struct qcom_glink *glink,
 656                         struct glink_channel *channel,
 657                         size_t size,
 658                         bool reuseable)
 659 {
 660         struct glink_core_rx_intent *intent;
 661         int ret;
 662         unsigned long flags;
 663
 664         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 665         if (!intent)
 666                 return NULL;
 667
 668         intent->data = kzalloc(size, GFP_KERNEL);
 669         if (!intent->data)
 670                 goto free_intent;
 671
 672         spin_lock_irqsave(&channel->intent_lock, flags);
 673         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 674         if (ret < 0) {
 675                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 676                 goto free_data;
 677         }
 678         spin_unlock_irqrestore(&channel->intent_lock, flags);
 679
 680         intent->id = ret;
 681         intent->size = size;
 682         intent->reuse = reuseable;
 683
 684         return intent;
 685
 686 free_data:
 687         kfree(intent->data);
 688 free_intent:
 689         kfree(intent);
 690         return NULL;
 691 }
 692
 693 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 694                                       u32 cid, uint32_t iid,
 695                                       bool reuse)
 696 {
 697         struct glink_core_rx_intent *intent;
 698         struct glink_channel *channel;
 699         unsigned long flags;
 700
 701         spin_lock_irqsave(&glink->idr_lock, flags);
 702         channel = idr_find(&glink->rcids, cid);
 703         spin_unlock_irqrestore(&glink->idr_lock, flags);
 704         if (!channel) {
 705                 dev_err(glink->dev, "invalid channel id received\n");
 706                 return;
 707         }
 708
 709         spin_lock_irqsave(&channel->intent_lock, flags);
 710         intent = idr_find(&channel->riids, iid);
 711
 712         if (!intent) {
 713                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 714                 dev_err(glink->dev, "invalid intent id received\n");
 715                 return;
 716         }
 717
 718         intent->in_use = false;
 719
 720         if (!reuse) {
 721                 idr_remove(&channel->riids, intent->id);
 722                 kfree(intent);
 723         }
 724         spin_unlock_irqrestore(&channel->intent_lock, flags);
 725 }
 726
 727 /**
 728  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 729  *                                          from remote side
 730  * if_ptr:      Pointer to the transport interface
 731  * rcid:        Remote channel ID
 732  * size:        size of the intent
 733  *
 734  * The function searches for the local channel to which the request for
 735  * rx_intent has arrived and allocates and notifies the remote back
 736  */
 737 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 738                                          u32 cid, size_t size)
 739 {
 740         struct glink_core_rx_intent *intent;
 741         struct glink_channel *channel;
 742         unsigned long flags;
 743
 744         spin_lock_irqsave(&glink->idr_lock, flags);
 745         channel = idr_find(&glink->rcids, cid);
 746         spin_unlock_irqrestore(&glink->idr_lock, flags);
 747
 748         if (!channel) {
 749                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 750                 return;
 751         }
 752
 753         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 754         if (intent)
 755                 qcom_glink_advertise_intent(glink, channel, intent);
 756
 757         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 758 }
 759
 760 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 761 {
 762         struct glink_defer_cmd *dcmd;
 763
 764         extra = ALIGN(extra, 8);
 765
 766         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 767                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 768                 return -ENXIO;
 769         }
 770
 771         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 772         if (!dcmd)
 773                 return -ENOMEM;
 774
 775         INIT_LIST_HEAD(&dcmd->node);
 776
 777         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 778
 779         spin_lock(&glink->rx_lock);
 780         list_add_tail(&dcmd->node, &glink->rx_queue);
 781         spin_unlock(&glink->rx_lock);
 782
 783         schedule_work(&glink->rx_work);
 784         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 785
 786         return 0;
 787 }
 788
 789 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 790 {
 791         struct glink_core_rx_intent *intent;
 792         struct glink_channel *channel;
 793         struct {
 794                 struct glink_msg msg;
 795                 __le32 chunk_size;
 796                 __le32 left_size;
 797         } __packed hdr;
 798         unsigned int chunk_size;
 799         unsigned int left_size;
 800         unsigned int rcid;
 801         unsigned int liid;
 802         int ret = 0;
 803         unsigned long flags;
 804
 805         if (avail < sizeof(hdr)) {
 806                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 807                 return -EAGAIN;
 808         }
 809
 810         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 811         chunk_size = le32_to_cpu(hdr.chunk_size);
 812         left_size = le32_to_cpu(hdr.left_size);
 813
 814         if (avail < sizeof(hdr) + chunk_size) {
 815                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 816                 return -EAGAIN;
 817         }
 818
 819         rcid = le16_to_cpu(hdr.msg.param1);
 820         spin_lock_irqsave(&glink->idr_lock, flags);
 821         channel = idr_find(&glink->rcids, rcid);
 822         spin_unlock_irqrestore(&glink->idr_lock, flags);
 823         if (!channel) {
 824                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 825
 826                 /* Drop the message */
 827                 goto advance_rx;
 828         }
 829
 830         if (glink->intentless) {
 831                 /* Might have an ongoing, fragmented, message to append */
 832                 if (!channel->buf) {
 833                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 834                         if (!intent)
 835                                 return -ENOMEM;
 836
 837                         intent->data = kmalloc(chunk_size + left_size,
 838                                                GFP_ATOMIC);
 839                         if (!intent->data) {
 840                                 kfree(intent);
 841                                 return -ENOMEM;
 842                         }
 843
 844                         intent->id = 0xbabababa;
 845                         intent->size = chunk_size + left_size;
 846                         intent->offset = 0;
 847
 848                         channel->buf = intent;
 849                 } else {
 850                         intent = channel->buf;
 851                 }
 852         } else {
 853                 liid = le32_to_cpu(hdr.msg.param2);
 854
 855                 spin_lock_irqsave(&channel->intent_lock, flags);
 856                 intent = idr_find(&channel->liids, liid);
 857                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 858
 859                 if (!intent) {
 860                         dev_err(glink->dev,
 861                                 "no intent found for channel %s intent %d",
 862                                 channel->name, liid);
 863                         ret = -ENOENT;
 864                         goto advance_rx;
 865                 }
 866         }
 867
 868         if (intent->size - intent->offset < chunk_size) {
 869                 dev_err(glink->dev, "Insufficient space in intent\n");
 870
 871                 /* The packet header lied, drop payload */
 872                 goto advance_rx;
 873         }
 874
 875         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 876                            sizeof(hdr), chunk_size);
 877         intent->offset += chunk_size;
 878
 879         /* Handle message when no fragments remain to be received */
 880         if (!left_size) {
 881                 spin_lock(&channel->recv_lock);
 882                 if (channel->ept.cb) {
 883                         channel->ept.cb(channel->ept.rpdev,
 884                                         intent->data,
 885                                         intent->offset,
 886                                         channel->ept.priv,
 887                                         RPMSG_ADDR_ANY);
 888                 }
 889                 spin_unlock(&channel->recv_lock);
 890
 891                 intent->offset = 0;
 892                 channel->buf = NULL;
 893
 894                 qcom_glink_rx_done(glink, channel, intent);
 895         }
 896
 897 advance_rx:
 898         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 899
 900         return ret;
 901 }
 902
 903 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 904                                      unsigned int cid,
 905                                      unsigned int count,
 906                                      size_t avail)
 907 {
 908         struct glink_core_rx_intent *intent;
 909         struct glink_channel *channel;
 910         struct intent_pair {
 911                 __le32 size;
 912                 __le32 iid;
 913         };
 914
 915         struct {
 916                 struct glink_msg msg;
 917                 struct intent_pair intents[];
 918         } __packed * msg;
 919
 920         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
 921         int ret;
 922         int i;
 923         unsigned long flags;
 924
 925         if (avail < msglen) {
 926                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 927                 return;
 928         }
 929
 930         spin_lock_irqsave(&glink->idr_lock, flags);
 931         channel = idr_find(&glink->rcids, cid);
 932         spin_unlock_irqrestore(&glink->idr_lock, flags);
 933         if (!channel) {
 934                 dev_err(glink->dev, "intents for non-existing channel\n");
 935                 qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 936                 return;
 937         }
 938
 939         msg = kmalloc(msglen, GFP_ATOMIC);
 940         if (!msg)
 941                 return;
 942
 943         qcom_glink_rx_peak(glink, msg, 0, msglen);
 944
 945         for (i = 0; i < count; ++i) {
 946                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 947                 if (!intent)
 948                         break;
 949
 950                 intent->id = le32_to_cpu(msg->intents[i].iid);
 951                 intent->size = le32_to_cpu(msg->intents[i].size);
 952
 953                 spin_lock_irqsave(&channel->intent_lock, flags);
 954                 ret = idr_alloc(&channel->riids, intent,
 955                                 intent->id, intent->id + 1, GFP_ATOMIC);
 956                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 957
 958                 if (ret < 0)
 959                         dev_err(glink->dev, "failed to store remote intent\n");
 960         }
 961
 962         kfree(msg);
 963         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 964 }
 965
 966 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 967 {
 968         struct glink_channel *channel;
 969
 970         spin_lock(&glink->idr_lock);
 971         channel = idr_find(&glink->lcids, lcid);
 972         spin_unlock(&glink->idr_lock);
 973         if (!channel) {
 974                 dev_err(glink->dev, "Invalid open ack packet\n");
 975                 return -EINVAL;
 976         }
 977
 978         complete(&channel->open_ack);
 979
 980         return 0;
 981 }
 982
 983 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 984 {
 985         struct qcom_glink *glink = data;
 986         struct glink_msg msg;
 987         unsigned int param1;
 988         unsigned int param2;
 989         unsigned int avail;
 990         unsigned int cmd;
 991         int ret = 0;
 992
 993         for (;;) {
 994                 avail = qcom_glink_rx_avail(glink);
 995                 if (avail < sizeof(msg))
 996                         break;
 997
 998                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 999
1000                 cmd = le16_to_cpu(msg.cmd);
1001                 param1 = le16_to_cpu(msg.param1);
1002                 param2 = le32_to_cpu(msg.param2);
1003
1004                 switch (cmd) {
1005                 case RPM_CMD_VERSION:
1006                 case RPM_CMD_VERSION_ACK:
1007                 case RPM_CMD_CLOSE:
1008                 case RPM_CMD_CLOSE_ACK:
1009                 case RPM_CMD_RX_INTENT_REQ:
1010                         ret = qcom_glink_rx_defer(glink, 0);
1011                         break;
1012                 case RPM_CMD_OPEN_ACK:
1013                         ret = qcom_glink_rx_open_ack(glink, param1);
1014                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1015                         break;
1016                 case RPM_CMD_OPEN:
1017                         ret = qcom_glink_rx_defer(glink, param2);
1018                         break;
1019                 case RPM_CMD_TX_DATA:
1020                 case RPM_CMD_TX_DATA_CONT:
1021                         ret = qcom_glink_rx_data(glink, avail);
1022                         break;
1023                 case RPM_CMD_READ_NOTIF:
1024                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1025
1026                         mbox_send_message(glink->mbox_chan, NULL);
1027                         mbox_client_txdone(glink->mbox_chan, 0);
1028                         break;
1029                 case RPM_CMD_INTENT:
1030                         qcom_glink_handle_intent(glink, param1, param2, avail);
1031                         break;
1032                 case RPM_CMD_RX_DONE:
1033                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1034                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1035                         break;
1036                 case RPM_CMD_RX_DONE_W_REUSE:
1037                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1038                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1039                         break;
1040                 case RPM_CMD_RX_INTENT_REQ_ACK:
1041                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1042                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1043                         break;
1044                 default:
1045                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1046                         ret = -EINVAL;
1047                         break;
1048                 }
1049
1050                 if (ret)
1051                         break;
1052         }
1053
1054         return IRQ_HANDLED;
1055 }
1056
1057 /* Locally initiated rpmsg_create_ept */
1058 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1059                                                      const char *name)
1060 {
1061         struct glink_channel *channel;
1062         int ret;
1063         unsigned long flags;
1064
1065         channel = qcom_glink_alloc_channel(glink, name);
1066         if (IS_ERR(channel))
1067                 return ERR_CAST(channel);
1068
1069         ret = qcom_glink_send_open_req(glink, channel);
1070         if (ret)
1071                 goto release_channel;
1072
1073         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1074         if (!ret)
1075                 goto err_timeout;
1076
1077         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1078         if (!ret)
1079                 goto err_timeout;
1080
1081         qcom_glink_send_open_ack(glink, channel);
1082
1083         return channel;
1084
1085 err_timeout:
1086         /* qcom_glink_send_open_req() did register the channel in lcids*/
1087         spin_lock_irqsave(&glink->idr_lock, flags);
1088         idr_remove(&glink->lcids, channel->lcid);
1089         spin_unlock_irqrestore(&glink->idr_lock, flags);
1090
1091 release_channel:
1092         /* Release qcom_glink_send_open_req() reference */
1093         kref_put(&channel->refcount, qcom_glink_channel_release);
1094         /* Release qcom_glink_alloc_channel() reference */
1095         kref_put(&channel->refcount, qcom_glink_channel_release);
1096
1097         return ERR_PTR(-ETIMEDOUT);
1098 }
1099
1100 /* Remote initiated rpmsg_create_ept */
1101 static int qcom_glink_create_remote(struct qcom_glink *glink,
1102                                     struct glink_channel *channel)
1103 {
1104         int ret;
1105
1106         qcom_glink_send_open_ack(glink, channel);
1107
1108         ret = qcom_glink_send_open_req(glink, channel);
1109         if (ret)
1110                 goto close_link;
1111
1112         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1113         if (!ret) {
1114                 ret = -ETIMEDOUT;
1115                 goto close_link;
1116         }
1117
1118         return 0;
1119
1120 close_link:
1121         /*
1122          * Send a close request to "undo" our open-ack. The close-ack will
1123          * release qcom_glink_send_open_req() reference and the last reference
1124          * will be relesed after receiving remote_close or transport unregister
1125          * by calling qcom_glink_native_remove().
1126          */
1127         qcom_glink_send_close_req(glink, channel);
1128
1129         return ret;
1130 }
1131
1132 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1133                                                     rpmsg_rx_cb_t cb,
1134                                                     void *priv,
1135                                                     struct rpmsg_channel_info
1136                                                                         chinfo)
1137 {
1138         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1139         struct glink_channel *channel;
1140         struct qcom_glink *glink = parent->glink;
1141         struct rpmsg_endpoint *ept;
1142         const char *name = chinfo.name;
1143         int cid;
1144         int ret;
1145         unsigned long flags;
1146
1147         spin_lock_irqsave(&glink->idr_lock, flags);
1148         idr_for_each_entry(&glink->rcids, channel, cid) {
1149                 if (!strcmp(channel->name, name))
1150                         break;
1151         }
1152         spin_unlock_irqrestore(&glink->idr_lock, flags);
1153
1154         if (!channel) {
1155                 channel = qcom_glink_create_local(glink, name);
1156                 if (IS_ERR(channel))
1157                         return NULL;
1158         } else {
1159                 ret = qcom_glink_create_remote(glink, channel);
1160                 if (ret)
1161                         return NULL;
1162         }
1163
1164         ept = &channel->ept;
1165         ept->rpdev = rpdev;
1166         ept->cb = cb;
1167         ept->priv = priv;
1168         ept->ops = &glink_endpoint_ops;
1169
1170         return ept;
1171 }
1172
1173 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1174 {
1175         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1176         struct glink_core_rx_intent *intent;
1177         struct qcom_glink *glink = channel->glink;
1178         int num_intents = glink->intentless ? 0 : 5;
1179
1180         /* Channel is now open, advertise base set of intents */
1181         while (num_intents--) {
1182                 intent = qcom_glink_alloc_intent(glink, channel, SZ_1K, true);
1183                 if (!intent)
1184                         break;
1185
1186                 qcom_glink_advertise_intent(glink, channel, intent);
1187         }
1188
1189         return 0;
1190 }
1191
1192 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1193 {
1194         struct glink_channel *channel = to_glink_channel(ept);
1195         struct qcom_glink *glink = channel->glink;
1196         unsigned long flags;
1197
1198         spin_lock_irqsave(&channel->recv_lock, flags);
1199         channel->ept.cb = NULL;
1200         spin_unlock_irqrestore(&channel->recv_lock, flags);
1201
1202         /* Decouple the potential rpdev from the channel */
1203         channel->rpdev = NULL;
1204
1205         qcom_glink_send_close_req(glink, channel);
1206 }
1207
1208 static int qcom_glink_request_intent(struct qcom_glink *glink,
1209                                      struct glink_channel *channel,
1210                                      size_t size)
1211 {
1212         struct {
1213                 u16 id;
1214                 u16 cid;
1215                 u32 size;
1216         } __packed cmd;
1217
1218         int ret;
1219
1220         mutex_lock(&channel->intent_req_lock);
1221
1222         reinit_completion(&channel->intent_req_comp);
1223
1224         cmd.id = RPM_CMD_RX_INTENT_REQ;
1225         cmd.cid = channel->lcid;
1226         cmd.size = size;
1227
1228         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1229         if (ret)
1230                 goto unlock;
1231
1232         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1233         if (!ret) {
1234                 dev_err(glink->dev, "intent request timed out\n");
1235                 ret = -ETIMEDOUT;
1236         } else {
1237                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1238         }
1239
1240 unlock:
1241         mutex_unlock(&channel->intent_req_lock);
1242         return ret;
1243 }
1244
1245 static int __qcom_glink_send(struct glink_channel *channel,
1246                              void *data, int len, bool wait)
1247 {
1248         struct qcom_glink *glink = channel->glink;
1249         struct glink_core_rx_intent *intent = NULL;
1250         struct glink_core_rx_intent *tmp;
1251         int iid = 0;
1252         struct {
1253                 struct glink_msg msg;
1254                 __le32 chunk_size;
1255                 __le32 left_size;
1256         } __packed req;
1257         int ret;
1258         unsigned long flags;
1259
1260         if (!glink->intentless) {
1261                 while (!intent) {
1262                         spin_lock_irqsave(&channel->intent_lock, flags);
1263                         idr_for_each_entry(&channel->riids, tmp, iid) {
1264                                 if (tmp->size >= len && !tmp->in_use) {
1265                                         tmp->in_use = true;
1266                                         intent = tmp;
1267                                         break;
1268                                 }
1269                         }
1270                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1271
1272                         /* We found an available intent */
1273                         if (intent)
1274                                 break;
1275
1276                         if (!wait)
1277                                 return -EBUSY;
1278
1279                         ret = qcom_glink_request_intent(glink, channel, len);
1280                         if (ret < 0)
1281                                 return ret;
1282                 }
1283
1284                 iid = intent->id;
1285         }
1286
1287         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1288         req.msg.param1 = cpu_to_le16(channel->lcid);
1289         req.msg.param2 = cpu_to_le32(iid);
1290         req.chunk_size = cpu_to_le32(len);
1291         req.left_size = cpu_to_le32(0);
1292
1293         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1294
1295         /* Mark intent available if we failed */
1296         if (ret && intent)
1297                 intent->in_use = false;
1298
1299         return ret;
1300 }
1301
1302 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1303 {
1304         struct glink_channel *channel = to_glink_channel(ept);
1305
1306         return __qcom_glink_send(channel, data, len, true);
1307 }
1308
1309 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1310 {
1311         struct glink_channel *channel = to_glink_channel(ept);
1312
1313         return __qcom_glink_send(channel, data, len, false);
1314 }
1315
1316 /*
1317  * Finds the device_node for the glink child interested in this channel.
1318  */
1319 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1320                                                     const char *channel)
1321 {
1322         struct device_node *child;
1323         const char *name;
1324         const char *key;
1325         int ret;
1326
1327         for_each_available_child_of_node(node, child) {
1328                 key = "qcom,glink-channels";
1329                 ret = of_property_read_string(child, key, &name);
1330                 if (ret)
1331                         continue;
1332
1333                 if (strcmp(name, channel) == 0)
1334                         return child;
1335         }
1336
1337         return NULL;
1338 }
1339
1340 static const struct rpmsg_device_ops glink_device_ops = {
1341         .create_ept = qcom_glink_create_ept,
1342         .announce_create = qcom_glink_announce_create,
1343 };
1344
1345 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1346         .destroy_ept = qcom_glink_destroy_ept,
1347         .send = qcom_glink_send,
1348         .trysend = qcom_glink_trysend,
1349 };
1350
1351 static void qcom_glink_rpdev_release(struct device *dev)
1352 {
1353         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1354         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1355
1356         channel->rpdev = NULL;
1357         kfree(rpdev->driver_override);
1358         kfree(rpdev);
1359 }
1360
1361 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1362                               char *name)
1363 {
1364         struct glink_channel *channel;
1365         struct rpmsg_device *rpdev;
1366         bool create_device = false;
1367         struct device_node *node;
1368         int lcid;
1369         int ret;
1370         unsigned long flags;
1371
1372         spin_lock_irqsave(&glink->idr_lock, flags);
1373         idr_for_each_entry(&glink->lcids, channel, lcid) {
1374                 if (!strcmp(channel->name, name))
1375                         break;
1376         }
1377         spin_unlock_irqrestore(&glink->idr_lock, flags);
1378
1379         if (!channel) {
1380                 channel = qcom_glink_alloc_channel(glink, name);
1381                 if (IS_ERR(channel))
1382                         return PTR_ERR(channel);
1383
1384                 /* The opening dance was initiated by the remote */
1385                 create_device = true;
1386         }
1387
1388         spin_lock_irqsave(&glink->idr_lock, flags);
1389         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1390         if (ret < 0) {
1391                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1392                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1393                 goto free_channel;
1394         }
1395         channel->rcid = ret;
1396         spin_unlock_irqrestore(&glink->idr_lock, flags);
1397
1398         complete(&channel->open_req);
1399
1400         if (create_device) {
1401                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1402                 if (!rpdev) {
1403                         ret = -ENOMEM;
1404                         goto rcid_remove;
1405                 }
1406
1407                 rpdev->ept = &channel->ept;
1408                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1409                 rpdev->src = RPMSG_ADDR_ANY;
1410                 rpdev->dst = RPMSG_ADDR_ANY;
1411                 rpdev->ops = &glink_device_ops;
1412
1413                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1414                 rpdev->dev.of_node = node;
1415                 rpdev->dev.parent = glink->dev;
1416                 rpdev->dev.release = qcom_glink_rpdev_release;
1417
1418                 ret = rpmsg_register_device(rpdev);
1419                 if (ret)
1420                         goto rcid_remove;
1421
1422                 channel->rpdev = rpdev;
1423         }
1424
1425         return 0;
1426
1427 rcid_remove:
1428         spin_lock_irqsave(&glink->idr_lock, flags);
1429         idr_remove(&glink->rcids, channel->rcid);
1430         channel->rcid = 0;
1431         spin_unlock_irqrestore(&glink->idr_lock, flags);
1432 free_channel:
1433         /* Release the reference, iff we took it */
1434         if (create_device)
1435                 kref_put(&channel->refcount, qcom_glink_channel_release);
1436
1437         return ret;
1438 }
1439
1440 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1441 {
1442         struct rpmsg_channel_info chinfo;
1443         struct glink_channel *channel;
1444         unsigned long flags;
1445
1446         spin_lock_irqsave(&glink->idr_lock, flags);
1447         channel = idr_find(&glink->rcids, rcid);
1448         spin_unlock_irqrestore(&glink->idr_lock, flags);
1449         if (WARN(!channel, "close request on unknown channel\n"))
1450                 return;
1451
1452         /* cancel pending rx_done work */
1453         cancel_work_sync(&channel->intent_work);
1454
1455         if (channel->rpdev) {
1456                 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1457                 chinfo.src = RPMSG_ADDR_ANY;
1458                 chinfo.dst = RPMSG_ADDR_ANY;
1459
1460                 rpmsg_unregister_device(glink->dev, &chinfo);
1461         }
1462
1463         qcom_glink_send_close_ack(glink, channel->rcid);
1464
1465         spin_lock_irqsave(&glink->idr_lock, flags);
1466         idr_remove(&glink->rcids, channel->rcid);
1467         channel->rcid = 0;
1468         spin_unlock_irqrestore(&glink->idr_lock, flags);
1469
1470         kref_put(&channel->refcount, qcom_glink_channel_release);
1471 }
1472
1473 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1474 {
1475         struct glink_channel *channel;
1476         unsigned long flags;
1477
1478         spin_lock_irqsave(&glink->idr_lock, flags);
1479         channel = idr_find(&glink->lcids, lcid);
1480         if (WARN(!channel, "close ack on unknown channel\n")) {
1481                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1482                 return;
1483         }
1484
1485         idr_remove(&glink->lcids, channel->lcid);
1486         channel->lcid = 0;
1487         spin_unlock_irqrestore(&glink->idr_lock, flags);
1488
1489         kref_put(&channel->refcount, qcom_glink_channel_release);
1490 }
1491
1492 static void qcom_glink_work(struct work_struct *work)
1493 {
1494         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1495                                                 rx_work);
1496         struct glink_defer_cmd *dcmd;
1497         struct glink_msg *msg;
1498         unsigned long flags;
1499         unsigned int param1;
1500         unsigned int param2;
1501         unsigned int cmd;
1502
1503         for (;;) {
1504                 spin_lock_irqsave(&glink->rx_lock, flags);
1505                 if (list_empty(&glink->rx_queue)) {
1506                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1507                         break;
1508                 }
1509                 dcmd = list_first_entry(&glink->rx_queue,
1510                                         struct glink_defer_cmd, node);
1511                 list_del(&dcmd->node);
1512                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1513
1514                 msg = &dcmd->msg;
1515                 cmd = le16_to_cpu(msg->cmd);
1516                 param1 = le16_to_cpu(msg->param1);
1517                 param2 = le32_to_cpu(msg->param2);
1518
1519                 switch (cmd) {
1520                 case RPM_CMD_VERSION:
1521                         qcom_glink_receive_version(glink, param1, param2);
1522                         break;
1523                 case RPM_CMD_VERSION_ACK:
1524                         qcom_glink_receive_version_ack(glink, param1, param2);
1525                         break;
1526                 case RPM_CMD_OPEN:
1527                         qcom_glink_rx_open(glink, param1, msg->data);
1528                         break;
1529                 case RPM_CMD_CLOSE:
1530                         qcom_glink_rx_close(glink, param1);
1531                         break;
1532                 case RPM_CMD_CLOSE_ACK:
1533                         qcom_glink_rx_close_ack(glink, param1);
1534                         break;
1535                 case RPM_CMD_RX_INTENT_REQ:
1536                         qcom_glink_handle_intent_req(glink, param1, param2);
1537                         break;
1538                 default:
1539                         WARN(1, "Unknown defer object %d\n", cmd);
1540                         break;
1541                 }
1542
1543                 kfree(dcmd);
1544         }
1545 }
1546
1547 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1548 {
1549         struct glink_defer_cmd *dcmd;
1550         struct glink_defer_cmd *tmp;
1551
1552         /* cancel any pending deferred rx_work */
1553         cancel_work_sync(&glink->rx_work);
1554
1555         list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1556                 kfree(dcmd);
1557 }
1558
1559 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1560                                            unsigned long features,
1561                                            struct qcom_glink_pipe *rx,
1562                                            struct qcom_glink_pipe *tx,
1563                                            bool intentless)
1564 {
1565         int irq;
1566         int ret;
1567         struct qcom_glink *glink;
1568
1569         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1570         if (!glink)
1571                 return ERR_PTR(-ENOMEM);
1572
1573         glink->dev = dev;
1574         glink->tx_pipe = tx;
1575         glink->rx_pipe = rx;
1576
1577         glink->features = features;
1578         glink->intentless = intentless;
1579
1580         mutex_init(&glink->tx_lock);
1581         spin_lock_init(&glink->rx_lock);
1582         INIT_LIST_HEAD(&glink->rx_queue);
1583         INIT_WORK(&glink->rx_work, qcom_glink_work);
1584
1585         spin_lock_init(&glink->idr_lock);
1586         idr_init(&glink->lcids);
1587         idr_init(&glink->rcids);
1588
1589         glink->mbox_client.dev = dev;
1590         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1591         if (IS_ERR(glink->mbox_chan)) {
1592                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1593                         dev_err(dev, "failed to acquire IPC channel\n");
1594                 return ERR_CAST(glink->mbox_chan);
1595         }
1596
1597         irq = of_irq_get(dev->of_node, 0);
1598         ret = devm_request_irq(dev, irq,
1599                                qcom_glink_native_intr,
1600                                IRQF_NO_SUSPEND | IRQF_SHARED,
1601                                "glink-native", glink);
1602         if (ret) {
1603                 dev_err(dev, "failed to request IRQ\n");
1604                 return ERR_PTR(ret);
1605         }
1606
1607         glink->irq = irq;
1608
1609         ret = qcom_glink_send_version(glink);
1610         if (ret)
1611                 return ERR_PTR(ret);
1612
1613         return glink;
1614 }
1615 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1616
1617 static int qcom_glink_remove_device(struct device *dev, void *data)
1618 {
1619         device_unregister(dev);
1620
1621         return 0;
1622 }
1623
1624 void qcom_glink_native_remove(struct qcom_glink *glink)
1625 {
1626         struct glink_channel *channel;
1627         int cid;
1628         int ret;
1629
1630         disable_irq(glink->irq);
1631         qcom_glink_cancel_rx_work(glink);
1632
1633         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1634         if (ret)
1635                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1636
1637         /* Release any defunct local channels, waiting for close-ack */
1638         idr_for_each_entry(&glink->lcids, channel, cid)
1639                 kref_put(&channel->refcount, qcom_glink_channel_release);
1640
1641         /* Release any defunct local channels, waiting for close-req */
1642         idr_for_each_entry(&glink->rcids, channel, cid)
1643                 kref_put(&channel->refcount, qcom_glink_channel_release);
1644
1645         idr_destroy(&glink->lcids);
1646         idr_destroy(&glink->rcids);
1647         mbox_free_channel(glink->mbox_chan);
1648 }
1649 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1650
1651 void qcom_glink_native_unregister(struct qcom_glink *glink)
1652 {
1653         device_unregister(glink->dev);
1654 }
1655 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1656
1657 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1658 MODULE_LICENSE("GPL v2");