drivers/rpmsg/qcom_glink_native.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016-2017, Linaro Ltd
   4  */
   5
   6 #include <linux/idr.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/list.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/of_address.h>
  14 #include <linux/of_irq.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17 #include <linux/rpmsg.h>
  18 #include <linux/sizes.h>
  19 #include <linux/slab.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/mailbox_client.h>
  22
  23 #include "rpmsg_internal.h"
  24 #include "qcom_glink_native.h"
  25
  26 #define GLINK_NAME_SIZE         32
  27 #define GLINK_VERSION_1         1
  28
  29 #define RPM_GLINK_CID_MIN       1
  30 #define RPM_GLINK_CID_MAX       65536
  31
  32 struct glink_msg {
  33         __le16 cmd;
  34         __le16 param1;
  35         __le32 param2;
  36         u8 data[];
  37 } __packed;
  38
  39 /**
  40  * struct glink_defer_cmd - deferred incoming control message
  41  * @node:       list node
  42  * @msg:        message header
  43  * @data:       payload of the message
  44  *
  45  * Copy of a received control message, to be added to @rx_queue and processed
  46  * by @rx_work of @qcom_glink.
  47  */
  48 struct glink_defer_cmd {
  49         struct list_head node;
  50
  51         struct glink_msg msg;
  52         u8 data[];
  53 };
  54
  55 /**
  56  * struct glink_core_rx_intent - RX intent
  57  * RX intent
  58  *
  59  * @data: pointer to the data (may be NULL for zero-copy)
  60  * @id: remote or local intent ID
  61  * @size: size of the original intent (do not modify)
  62  * @reuse: To mark if the intent can be reused after first use
  63  * @in_use: To mark if intent is already in use for the channel
  64  * @offset: next write offset (initially 0)
  65  * @node:       list node
  66  */
  67 struct glink_core_rx_intent {
  68         void *data;
  69         u32 id;
  70         size_t size;
  71         bool reuse;
  72         bool in_use;
  73         u32 offset;
  74
  75         struct list_head node;
  76 };
  77
  78 /**
  79  * struct qcom_glink - driver context, relates to one remote subsystem
  80  * @dev:        reference to the associated struct device
  81  * @mbox_client: mailbox client
  82  * @mbox_chan:  mailbox channel
  83  * @rx_pipe:    pipe object for receive FIFO
  84  * @tx_pipe:    pipe object for transmit FIFO
  85  * @irq:        IRQ for signaling incoming events
  86  * @rx_work:    worker for handling received control messages
  87  * @rx_lock:    protects the @rx_queue
  88  * @rx_queue:   queue of received control messages to be processed in @rx_work
  89  * @tx_lock:    synchronizes operations on the tx fifo
  90  * @idr_lock:   synchronizes @lcids and @rcids modifications
  91  * @lcids:      idr of all channels with a known local channel id
  92  * @rcids:      idr of all channels with a known remote channel id
  93  * @features:   remote features
  94  * @intentless: flag to indicate that there is no intent
  95  */
  96 struct qcom_glink {
  97         struct device *dev;
  98
  99         const char *name;
 100
 101         struct mbox_client mbox_client;
 102         struct mbox_chan *mbox_chan;
 103
 104         struct qcom_glink_pipe *rx_pipe;
 105         struct qcom_glink_pipe *tx_pipe;
 106
 107         int irq;
 108
 109         struct work_struct rx_work;
 110         spinlock_t rx_lock;
 111         struct list_head rx_queue;
 112
 113         spinlock_t tx_lock;
 114
 115         spinlock_t idr_lock;
 116         struct idr lcids;
 117         struct idr rcids;
 118         unsigned long features;
 119
 120         bool intentless;
 121 };
 122
 123 enum {
 124         GLINK_STATE_CLOSED,
 125         GLINK_STATE_OPENING,
 126         GLINK_STATE_OPEN,
 127         GLINK_STATE_CLOSING,
 128 };
 129
 130 /**
 131  * struct glink_channel - internal representation of a channel
 132  * @rpdev:      rpdev reference, only used for primary endpoints
 133  * @ept:        rpmsg endpoint this channel is associated with
 134  * @glink:      qcom_glink context handle
 135  * @refcount:   refcount for the channel object
 136  * @recv_lock:  guard for @ept.cb
 137  * @name:       unique channel name/identifier
 138  * @lcid:       channel id, in local space
 139  * @rcid:       channel id, in remote space
 140  * @intent_lock: lock for protection of @liids, @riids
 141  * @liids:      idr of all local intents
 142  * @riids:      idr of all remote intents
 143  * @intent_work: worker responsible for transmitting rx_done packets
 144  * @done_intents: list of intents that needs to be announced rx_done
 145  * @buf:        receive buffer, for gathering fragments
 146  * @buf_offset: write offset in @buf
 147  * @buf_size:   size of current @buf
 148  * @open_ack:   completed once remote has acked the open-request
 149  * @open_req:   completed once open-request has been received
 150  * @intent_req_lock: Synchronises multiple intent requests
 151  * @intent_req_result: Result of intent request
 152  * @intent_req_comp: Completion for intent_req signalling
 153  */
 154 struct glink_channel {
 155         struct rpmsg_endpoint ept;
 156
 157         struct rpmsg_device *rpdev;
 158         struct qcom_glink *glink;
 159
 160         struct kref refcount;
 161
 162         spinlock_t recv_lock;
 163
 164         char *name;
 165         unsigned int lcid;
 166         unsigned int rcid;
 167
 168         spinlock_t intent_lock;
 169         struct idr liids;
 170         struct idr riids;
 171         struct work_struct intent_work;
 172         struct list_head done_intents;
 173
 174         struct glink_core_rx_intent *buf;
 175         int buf_offset;
 176         int buf_size;
 177
 178         struct completion open_ack;
 179         struct completion open_req;
 180
 181         struct mutex intent_req_lock;
 182         bool intent_req_result;
 183         struct completion intent_req_comp;
 184 };
 185
 186 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
 187
 188 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
 189
 190 #define RPM_CMD_VERSION                 0
 191 #define RPM_CMD_VERSION_ACK             1
 192 #define RPM_CMD_OPEN                    2
 193 #define RPM_CMD_CLOSE                   3
 194 #define RPM_CMD_OPEN_ACK                4
 195 #define RPM_CMD_INTENT                  5
 196 #define RPM_CMD_RX_DONE                 6
 197 #define RPM_CMD_RX_INTENT_REQ           7
 198 #define RPM_CMD_RX_INTENT_REQ_ACK       8
 199 #define RPM_CMD_TX_DATA                 9
 200 #define RPM_CMD_CLOSE_ACK               11
 201 #define RPM_CMD_TX_DATA_CONT            12
 202 #define RPM_CMD_READ_NOTIF              13
 203 #define RPM_CMD_RX_DONE_W_REUSE         14
 204
 205 #define GLINK_FEATURE_INTENTLESS        BIT(1)
 206
 207 static void qcom_glink_rx_done_work(struct work_struct *work);
 208
 209 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 210                                                       const char *name)
 211 {
 212         struct glink_channel *channel;
 213
 214         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 215         if (!channel)
 216                 return ERR_PTR(-ENOMEM);
 217
 218         /* Setup glink internal glink_channel data */
 219         spin_lock_init(&channel->recv_lock);
 220         spin_lock_init(&channel->intent_lock);
 221         mutex_init(&channel->intent_req_lock);
 222
 223         channel->glink = glink;
 224         channel->name = kstrdup(name, GFP_KERNEL);
 225
 226         init_completion(&channel->open_req);
 227         init_completion(&channel->open_ack);
 228         init_completion(&channel->intent_req_comp);
 229
 230         INIT_LIST_HEAD(&channel->done_intents);
 231         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 232
 233         idr_init(&channel->liids);
 234         idr_init(&channel->riids);
 235         kref_init(&channel->refcount);
 236
 237         return channel;
 238 }
 239
 240 static void qcom_glink_channel_release(struct kref *ref)
 241 {
 242         struct glink_channel *channel = container_of(ref, struct glink_channel,
 243                                                      refcount);
 244         struct glink_core_rx_intent *intent;
 245         struct glink_core_rx_intent *tmp;
 246         unsigned long flags;
 247         int iid;
 248
 249         /* cancel pending rx_done work */
 250         cancel_work_sync(&channel->intent_work);
 251
 252         spin_lock_irqsave(&channel->intent_lock, flags);
 253         /* Free all non-reuse intents pending rx_done work */
 254         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 255                 if (!intent->reuse) {
 256                         kfree(intent->data);
 257                         kfree(intent);
 258                 }
 259         }
 260
 261         idr_for_each_entry(&channel->liids, tmp, iid) {
 262                 kfree(tmp->data);
 263                 kfree(tmp);
 264         }
 265         idr_destroy(&channel->liids);
 266
 267         idr_for_each_entry(&channel->riids, tmp, iid)
 268                 kfree(tmp);
 269         idr_destroy(&channel->riids);
 270         spin_unlock_irqrestore(&channel->intent_lock, flags);
 271
 272         kfree(channel->name);
 273         kfree(channel);
 274 }
 275
 276 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 277 {
 278         return glink->rx_pipe->avail(glink->rx_pipe);
 279 }
 280
 281 static void qcom_glink_rx_peak(struct qcom_glink *glink,
 282                                void *data, unsigned int offset, size_t count)
 283 {
 284         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 285 }
 286
 287 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
 288 {
 289         glink->rx_pipe->advance(glink->rx_pipe, count);
 290 }
 291
 292 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
 293 {
 294         return glink->tx_pipe->avail(glink->tx_pipe);
 295 }
 296
 297 static void qcom_glink_tx_write(struct qcom_glink *glink,
 298                                 const void *hdr, size_t hlen,
 299                                 const void *data, size_t dlen)
 300 {
 301         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
 302 }
 303
 304 static int qcom_glink_tx(struct qcom_glink *glink,
 305                          const void *hdr, size_t hlen,
 306                          const void *data, size_t dlen, bool wait)
 307 {
 308         unsigned int tlen = hlen + dlen;
 309         unsigned long flags;
 310         int ret = 0;
 311
 312         /* Reject packets that are too big */
 313         if (tlen >= glink->tx_pipe->length)
 314                 return -EINVAL;
 315
 316         spin_lock_irqsave(&glink->tx_lock, flags);
 317
 318         while (qcom_glink_tx_avail(glink) < tlen) {
 319                 if (!wait) {
 320                         ret = -EAGAIN;
 321                         goto out;
 322                 }
 323
 324                 /* Wait without holding the tx_lock */
 325                 spin_unlock_irqrestore(&glink->tx_lock, flags);
 326
 327                 usleep_range(10000, 15000);
 328
 329                 spin_lock_irqsave(&glink->tx_lock, flags);
 330         }
 331
 332         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
 333
 334         mbox_send_message(glink->mbox_chan, NULL);
 335         mbox_client_txdone(glink->mbox_chan, 0);
 336
 337 out:
 338         spin_unlock_irqrestore(&glink->tx_lock, flags);
 339
 340         return ret;
 341 }
 342
 343 static int qcom_glink_send_version(struct qcom_glink *glink)
 344 {
 345         struct glink_msg msg;
 346
 347         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
 348         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 349         msg.param2 = cpu_to_le32(glink->features);
 350
 351         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 352 }
 353
 354 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
 355 {
 356         struct glink_msg msg;
 357
 358         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
 359         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
 360         msg.param2 = cpu_to_le32(glink->features);
 361
 362         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 363 }
 364
 365 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
 366                                      struct glink_channel *channel)
 367 {
 368         struct glink_msg msg;
 369
 370         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
 371         msg.param1 = cpu_to_le16(channel->rcid);
 372         msg.param2 = cpu_to_le32(0);
 373
 374         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 375 }
 376
 377 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
 378                                              unsigned int cid, bool granted)
 379 {
 380         struct glink_channel *channel;
 381         unsigned long flags;
 382
 383         spin_lock_irqsave(&glink->idr_lock, flags);
 384         channel = idr_find(&glink->rcids, cid);
 385         spin_unlock_irqrestore(&glink->idr_lock, flags);
 386         if (!channel) {
 387                 dev_err(glink->dev, "unable to find channel\n");
 388                 return;
 389         }
 390
 391         channel->intent_req_result = granted;
 392         complete(&channel->intent_req_comp);
 393 }
 394
 395 /**
 396  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
 397  * @glink: Ptr to the glink edge
 398  * @channel: Ptr to the channel that the open req is sent
 399  *
 400  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
 401  * Will return with refcount held, regardless of outcome.
 402  *
 403  * Returns 0 on success, negative errno otherwise.
 404  */
 405 static int qcom_glink_send_open_req(struct qcom_glink *glink,
 406                                     struct glink_channel *channel)
 407 {
 408         struct {
 409                 struct glink_msg msg;
 410                 u8 name[GLINK_NAME_SIZE];
 411         } __packed req;
 412         int name_len = strlen(channel->name) + 1;
 413         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
 414         int ret;
 415         unsigned long flags;
 416
 417         kref_get(&channel->refcount);
 418
 419         spin_lock_irqsave(&glink->idr_lock, flags);
 420         ret = idr_alloc_cyclic(&glink->lcids, channel,
 421                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
 422                                GFP_ATOMIC);
 423         spin_unlock_irqrestore(&glink->idr_lock, flags);
 424         if (ret < 0)
 425                 return ret;
 426
 427         channel->lcid = ret;
 428
 429         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
 430         req.msg.param1 = cpu_to_le16(channel->lcid);
 431         req.msg.param2 = cpu_to_le32(name_len);
 432         strcpy(req.name, channel->name);
 433
 434         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
 435         if (ret)
 436                 goto remove_idr;
 437
 438         return 0;
 439
 440 remove_idr:
 441         spin_lock_irqsave(&glink->idr_lock, flags);
 442         idr_remove(&glink->lcids, channel->lcid);
 443         channel->lcid = 0;
 444         spin_unlock_irqrestore(&glink->idr_lock, flags);
 445
 446         return ret;
 447 }
 448
 449 static void qcom_glink_send_close_req(struct qcom_glink *glink,
 450                                       struct glink_channel *channel)
 451 {
 452         struct glink_msg req;
 453
 454         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
 455         req.param1 = cpu_to_le16(channel->lcid);
 456         req.param2 = 0;
 457
 458         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 459 }
 460
 461 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
 462                                       unsigned int rcid)
 463 {
 464         struct glink_msg req;
 465
 466         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
 467         req.param1 = cpu_to_le16(rcid);
 468         req.param2 = 0;
 469
 470         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
 471 }
 472
 473 static void qcom_glink_rx_done_work(struct work_struct *work)
 474 {
 475         struct glink_channel *channel = container_of(work, struct glink_channel,
 476                                                      intent_work);
 477         struct qcom_glink *glink = channel->glink;
 478         struct glink_core_rx_intent *intent, *tmp;
 479         struct {
 480                 u16 id;
 481                 u16 lcid;
 482                 u32 liid;
 483         } __packed cmd;
 484
 485         unsigned int cid = channel->lcid;
 486         unsigned int iid;
 487         bool reuse;
 488         unsigned long flags;
 489
 490         spin_lock_irqsave(&channel->intent_lock, flags);
 491         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
 492                 list_del(&intent->node);
 493                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 494                 iid = intent->id;
 495                 reuse = intent->reuse;
 496
 497                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
 498                 cmd.lcid = cid;
 499                 cmd.liid = iid;
 500
 501                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 502                 if (!reuse) {
 503                         kfree(intent->data);
 504                         kfree(intent);
 505                 }
 506                 spin_lock_irqsave(&channel->intent_lock, flags);
 507         }
 508         spin_unlock_irqrestore(&channel->intent_lock, flags);
 509 }
 510
 511 static void qcom_glink_rx_done(struct qcom_glink *glink,
 512                                struct glink_channel *channel,
 513                                struct glink_core_rx_intent *intent)
 514 {
 515         /* We don't send RX_DONE to intentless systems */
 516         if (glink->intentless) {
 517                 kfree(intent->data);
 518                 kfree(intent);
 519                 return;
 520         }
 521
 522         /* Take it off the tree of receive intents */
 523         if (!intent->reuse) {
 524                 spin_lock(&channel->intent_lock);
 525                 idr_remove(&channel->liids, intent->id);
 526                 spin_unlock(&channel->intent_lock);
 527         }
 528
 529         /* Schedule the sending of a rx_done indication */
 530         spin_lock(&channel->intent_lock);
 531         list_add_tail(&intent->node, &channel->done_intents);
 532         spin_unlock(&channel->intent_lock);
 533
 534         schedule_work(&channel->intent_work);
 535 }
 536
 537 /**
 538  * qcom_glink_receive_version() - receive version/features from remote system
 539  *
 540  * @glink:      pointer to transport interface
 541  * @version:    remote version
 542  * @features:   remote features
 543  *
 544  * This function is called in response to a remote-initiated version/feature
 545  * negotiation sequence.
 546  */
 547 static void qcom_glink_receive_version(struct qcom_glink *glink,
 548                                        u32 version,
 549                                        u32 features)
 550 {
 551         switch (version) {
 552         case 0:
 553                 break;
 554         case GLINK_VERSION_1:
 555                 glink->features &= features;
 556                 fallthrough;
 557         default:
 558                 qcom_glink_send_version_ack(glink);
 559                 break;
 560         }
 561 }
 562
 563 /**
 564  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
 565  *
 566  * @glink:      pointer to transport interface
 567  * @version:    remote version response
 568  * @features:   remote features response
 569  *
 570  * This function is called in response to a local-initiated version/feature
 571  * negotiation sequence and is the counter-offer from the remote side based
 572  * upon the initial version and feature set requested.
 573  */
 574 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
 575                                            u32 version,
 576                                            u32 features)
 577 {
 578         switch (version) {
 579         case 0:
 580                 /* Version negotiation failed */
 581                 break;
 582         case GLINK_VERSION_1:
 583                 if (features == glink->features)
 584                         break;
 585
 586                 glink->features &= features;
 587                 fallthrough;
 588         default:
 589                 qcom_glink_send_version(glink);
 590                 break;
 591         }
 592 }
 593
 594 /**
 595  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
 596  *      wire format and transmit
 597  * @glink:      The transport to transmit on.
 598  * @channel:    The glink channel
 599  * @granted:    The request response to encode.
 600  *
 601  * Return: 0 on success or standard Linux error code.
 602  */
 603 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
 604                                           struct glink_channel *channel,
 605                                           bool granted)
 606 {
 607         struct glink_msg msg;
 608
 609         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
 610         msg.param1 = cpu_to_le16(channel->lcid);
 611         msg.param2 = cpu_to_le32(granted);
 612
 613         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
 614
 615         return 0;
 616 }
 617
 618 /**
 619  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
 620  *                         transmit
 621  * @glink:      The transport to transmit on.
 622  * @channel:    The local channel
 623  * @intent:     The intent to pass on to remote.
 624  *
 625  * Return: 0 on success or standard Linux error code.
 626  */
 627 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
 628                                        struct glink_channel *channel,
 629                                        struct glink_core_rx_intent *intent)
 630 {
 631         struct command {
 632                 __le16 id;
 633                 __le16 lcid;
 634                 __le32 count;
 635                 __le32 size;
 636                 __le32 liid;
 637         } __packed;
 638         struct command cmd;
 639
 640         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
 641         cmd.lcid = cpu_to_le16(channel->lcid);
 642         cmd.count = cpu_to_le32(1);
 643         cmd.size = cpu_to_le32(intent->size);
 644         cmd.liid = cpu_to_le32(intent->id);
 645
 646         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
 647
 648         return 0;
 649 }
 650
 651 static struct glink_core_rx_intent *
 652 qcom_glink_alloc_intent(struct qcom_glink *glink,
 653                         struct glink_channel *channel,
 654                         size_t size,
 655                         bool reuseable)
 656 {
 657         struct glink_core_rx_intent *intent;
 658         int ret;
 659         unsigned long flags;
 660
 661         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
 662         if (!intent)
 663                 return NULL;
 664
 665         intent->data = kzalloc(size, GFP_KERNEL);
 666         if (!intent->data)
 667                 goto free_intent;
 668
 669         spin_lock_irqsave(&channel->intent_lock, flags);
 670         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
 671         if (ret < 0) {
 672                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 673                 goto free_data;
 674         }
 675         spin_unlock_irqrestore(&channel->intent_lock, flags);
 676
 677         intent->id = ret;
 678         intent->size = size;
 679         intent->reuse = reuseable;
 680
 681         return intent;
 682
 683 free_data:
 684         kfree(intent->data);
 685 free_intent:
 686         kfree(intent);
 687         return NULL;
 688 }
 689
 690 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
 691                                       u32 cid, uint32_t iid,
 692                                       bool reuse)
 693 {
 694         struct glink_core_rx_intent *intent;
 695         struct glink_channel *channel;
 696         unsigned long flags;
 697
 698         spin_lock_irqsave(&glink->idr_lock, flags);
 699         channel = idr_find(&glink->rcids, cid);
 700         spin_unlock_irqrestore(&glink->idr_lock, flags);
 701         if (!channel) {
 702                 dev_err(glink->dev, "invalid channel id received\n");
 703                 return;
 704         }
 705
 706         spin_lock_irqsave(&channel->intent_lock, flags);
 707         intent = idr_find(&channel->riids, iid);
 708
 709         if (!intent) {
 710                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 711                 dev_err(glink->dev, "invalid intent id received\n");
 712                 return;
 713         }
 714
 715         intent->in_use = false;
 716
 717         if (!reuse) {
 718                 idr_remove(&channel->riids, intent->id);
 719                 kfree(intent);
 720         }
 721         spin_unlock_irqrestore(&channel->intent_lock, flags);
 722 }
 723
 724 /**
 725  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
 726  *                                          from remote side
 727  * @glink:      Pointer to the transport interface
 728  * @cid:        Remote channel ID
 729  * @size:       size of the intent
 730  *
 731  * The function searches for the local channel to which the request for
 732  * rx_intent has arrived and allocates and notifies the remote back
 733  */
 734 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
 735                                          u32 cid, size_t size)
 736 {
 737         struct glink_core_rx_intent *intent;
 738         struct glink_channel *channel;
 739         unsigned long flags;
 740
 741         spin_lock_irqsave(&glink->idr_lock, flags);
 742         channel = idr_find(&glink->rcids, cid);
 743         spin_unlock_irqrestore(&glink->idr_lock, flags);
 744
 745         if (!channel) {
 746                 pr_err("%s channel not found for cid %d\n", __func__, cid);
 747                 return;
 748         }
 749
 750         intent = qcom_glink_alloc_intent(glink, channel, size, false);
 751         if (intent)
 752                 qcom_glink_advertise_intent(glink, channel, intent);
 753
 754         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
 755 }
 756
 757 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 758 {
 759         struct glink_defer_cmd *dcmd;
 760
 761         extra = ALIGN(extra, 8);
 762
 763         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
 764                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
 765                 return -ENXIO;
 766         }
 767
 768         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
 769         if (!dcmd)
 770                 return -ENOMEM;
 771
 772         INIT_LIST_HEAD(&dcmd->node);
 773
 774         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 775
 776         spin_lock(&glink->rx_lock);
 777         list_add_tail(&dcmd->node, &glink->rx_queue);
 778         spin_unlock(&glink->rx_lock);
 779
 780         schedule_work(&glink->rx_work);
 781         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
 782
 783         return 0;
 784 }
 785
 786 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 787 {
 788         struct glink_core_rx_intent *intent;
 789         struct glink_channel *channel;
 790         struct {
 791                 struct glink_msg msg;
 792                 __le32 chunk_size;
 793                 __le32 left_size;
 794         } __packed hdr;
 795         unsigned int chunk_size;
 796         unsigned int left_size;
 797         unsigned int rcid;
 798         unsigned int liid;
 799         int ret = 0;
 800         unsigned long flags;
 801
 802         if (avail < sizeof(hdr)) {
 803                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 804                 return -EAGAIN;
 805         }
 806
 807         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 808         chunk_size = le32_to_cpu(hdr.chunk_size);
 809         left_size = le32_to_cpu(hdr.left_size);
 810
 811         if (avail < sizeof(hdr) + chunk_size) {
 812                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
 813                 return -EAGAIN;
 814         }
 815
 816         rcid = le16_to_cpu(hdr.msg.param1);
 817         spin_lock_irqsave(&glink->idr_lock, flags);
 818         channel = idr_find(&glink->rcids, rcid);
 819         spin_unlock_irqrestore(&glink->idr_lock, flags);
 820         if (!channel) {
 821                 dev_dbg(glink->dev, "Data on non-existing channel\n");
 822
 823                 /* Drop the message */
 824                 goto advance_rx;
 825         }
 826
 827         if (glink->intentless) {
 828                 /* Might have an ongoing, fragmented, message to append */
 829                 if (!channel->buf) {
 830                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 831                         if (!intent)
 832                                 return -ENOMEM;
 833
 834                         intent->data = kmalloc(chunk_size + left_size,
 835                                                GFP_ATOMIC);
 836                         if (!intent->data) {
 837                                 kfree(intent);
 838                                 return -ENOMEM;
 839                         }
 840
 841                         intent->id = 0xbabababa;
 842                         intent->size = chunk_size + left_size;
 843                         intent->offset = 0;
 844
 845                         channel->buf = intent;
 846                 } else {
 847                         intent = channel->buf;
 848                 }
 849         } else {
 850                 liid = le32_to_cpu(hdr.msg.param2);
 851
 852                 spin_lock_irqsave(&channel->intent_lock, flags);
 853                 intent = idr_find(&channel->liids, liid);
 854                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 855
 856                 if (!intent) {
 857                         dev_err(glink->dev,
 858                                 "no intent found for channel %s intent %d",
 859                                 channel->name, liid);
 860                         goto advance_rx;
 861                 }
 862         }
 863
 864         if (intent->size - intent->offset < chunk_size) {
 865                 dev_err(glink->dev, "Insufficient space in intent\n");
 866
 867                 /* The packet header lied, drop payload */
 868                 goto advance_rx;
 869         }
 870
 871         qcom_glink_rx_peak(glink, intent->data + intent->offset,
 872                            sizeof(hdr), chunk_size);
 873         intent->offset += chunk_size;
 874
 875         /* Handle message when no fragments remain to be received */
 876         if (!left_size) {
 877                 spin_lock(&channel->recv_lock);
 878                 if (channel->ept.cb) {
 879                         channel->ept.cb(channel->ept.rpdev,
 880                                         intent->data,
 881                                         intent->offset,
 882                                         channel->ept.priv,
 883                                         RPMSG_ADDR_ANY);
 884                 }
 885                 spin_unlock(&channel->recv_lock);
 886
 887                 intent->offset = 0;
 888                 channel->buf = NULL;
 889
 890                 qcom_glink_rx_done(glink, channel, intent);
 891         }
 892
 893 advance_rx:
 894         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 895
 896         return ret;
 897 }
 898
 899 static void qcom_glink_handle_intent(struct qcom_glink *glink,
 900                                      unsigned int cid,
 901                                      unsigned int count,
 902                                      size_t avail)
 903 {
 904         struct glink_core_rx_intent *intent;
 905         struct glink_channel *channel;
 906         struct intent_pair {
 907                 __le32 size;
 908                 __le32 iid;
 909         };
 910
 911         struct {
 912                 struct glink_msg msg;
 913                 struct intent_pair intents[];
 914         } __packed * msg;
 915
 916         const size_t msglen = struct_size(msg, intents, count);
 917         int ret;
 918         int i;
 919         unsigned long flags;
 920
 921         if (avail < msglen) {
 922                 dev_dbg(glink->dev, "Not enough data in fifo\n");
 923                 return;
 924         }
 925
 926         spin_lock_irqsave(&glink->idr_lock, flags);
 927         channel = idr_find(&glink->rcids, cid);
 928         spin_unlock_irqrestore(&glink->idr_lock, flags);
 929         if (!channel) {
 930                 dev_err(glink->dev, "intents for non-existing channel\n");
 931                 return;
 932         }
 933
 934         msg = kmalloc(msglen, GFP_ATOMIC);
 935         if (!msg)
 936                 return;
 937
 938         qcom_glink_rx_peak(glink, msg, 0, msglen);
 939
 940         for (i = 0; i < count; ++i) {
 941                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
 942                 if (!intent)
 943                         break;
 944
 945                 intent->id = le32_to_cpu(msg->intents[i].iid);
 946                 intent->size = le32_to_cpu(msg->intents[i].size);
 947
 948                 spin_lock_irqsave(&channel->intent_lock, flags);
 949                 ret = idr_alloc(&channel->riids, intent,
 950                                 intent->id, intent->id + 1, GFP_ATOMIC);
 951                 spin_unlock_irqrestore(&channel->intent_lock, flags);
 952
 953                 if (ret < 0)
 954                         dev_err(glink->dev, "failed to store remote intent\n");
 955         }
 956
 957         kfree(msg);
 958         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
 959 }
 960
 961 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 962 {
 963         struct glink_channel *channel;
 964
 965         spin_lock(&glink->idr_lock);
 966         channel = idr_find(&glink->lcids, lcid);
 967         spin_unlock(&glink->idr_lock);
 968         if (!channel) {
 969                 dev_err(glink->dev, "Invalid open ack packet\n");
 970                 return -EINVAL;
 971         }
 972
 973         complete_all(&channel->open_ack);
 974
 975         return 0;
 976 }
 977
 978 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 979 {
 980         struct qcom_glink *glink = data;
 981         struct glink_msg msg;
 982         unsigned int param1;
 983         unsigned int param2;
 984         unsigned int avail;
 985         unsigned int cmd;
 986         int ret = 0;
 987
 988         for (;;) {
 989                 avail = qcom_glink_rx_avail(glink);
 990                 if (avail < sizeof(msg))
 991                         break;
 992
 993                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 994
 995                 cmd = le16_to_cpu(msg.cmd);
 996                 param1 = le16_to_cpu(msg.param1);
 997                 param2 = le32_to_cpu(msg.param2);
 998
 999                 switch (cmd) {
1000                 case RPM_CMD_VERSION:
1001                 case RPM_CMD_VERSION_ACK:
1002                 case RPM_CMD_CLOSE:
1003                 case RPM_CMD_CLOSE_ACK:
1004                 case RPM_CMD_RX_INTENT_REQ:
1005                         ret = qcom_glink_rx_defer(glink, 0);
1006                         break;
1007                 case RPM_CMD_OPEN_ACK:
1008                         ret = qcom_glink_rx_open_ack(glink, param1);
1009                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1010                         break;
1011                 case RPM_CMD_OPEN:
1012                         ret = qcom_glink_rx_defer(glink, param2);
1013                         break;
1014                 case RPM_CMD_TX_DATA:
1015                 case RPM_CMD_TX_DATA_CONT:
1016                         ret = qcom_glink_rx_data(glink, avail);
1017                         break;
1018                 case RPM_CMD_READ_NOTIF:
1019                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1020
1021                         mbox_send_message(glink->mbox_chan, NULL);
1022                         mbox_client_txdone(glink->mbox_chan, 0);
1023                         break;
1024                 case RPM_CMD_INTENT:
1025                         qcom_glink_handle_intent(glink, param1, param2, avail);
1026                         break;
1027                 case RPM_CMD_RX_DONE:
1028                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1029                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1030                         break;
1031                 case RPM_CMD_RX_DONE_W_REUSE:
1032                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1033                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1034                         break;
1035                 case RPM_CMD_RX_INTENT_REQ_ACK:
1036                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1037                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1038                         break;
1039                 default:
1040                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1041                         ret = -EINVAL;
1042                         break;
1043                 }
1044
1045                 if (ret)
1046                         break;
1047         }
1048
1049         return IRQ_HANDLED;
1050 }
1051
1052 /* Locally initiated rpmsg_create_ept */
1053 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1054                                                      const char *name)
1055 {
1056         struct glink_channel *channel;
1057         int ret;
1058         unsigned long flags;
1059
1060         channel = qcom_glink_alloc_channel(glink, name);
1061         if (IS_ERR(channel))
1062                 return ERR_CAST(channel);
1063
1064         ret = qcom_glink_send_open_req(glink, channel);
1065         if (ret)
1066                 goto release_channel;
1067
1068         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1069         if (!ret)
1070                 goto err_timeout;
1071
1072         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1073         if (!ret)
1074                 goto err_timeout;
1075
1076         qcom_glink_send_open_ack(glink, channel);
1077
1078         return channel;
1079
1080 err_timeout:
1081         /* qcom_glink_send_open_req() did register the channel in lcids*/
1082         spin_lock_irqsave(&glink->idr_lock, flags);
1083         idr_remove(&glink->lcids, channel->lcid);
1084         spin_unlock_irqrestore(&glink->idr_lock, flags);
1085
1086 release_channel:
1087         /* Release qcom_glink_send_open_req() reference */
1088         kref_put(&channel->refcount, qcom_glink_channel_release);
1089         /* Release qcom_glink_alloc_channel() reference */
1090         kref_put(&channel->refcount, qcom_glink_channel_release);
1091
1092         return ERR_PTR(-ETIMEDOUT);
1093 }
1094
1095 /* Remote initiated rpmsg_create_ept */
1096 static int qcom_glink_create_remote(struct qcom_glink *glink,
1097                                     struct glink_channel *channel)
1098 {
1099         int ret;
1100
1101         qcom_glink_send_open_ack(glink, channel);
1102
1103         ret = qcom_glink_send_open_req(glink, channel);
1104         if (ret)
1105                 goto close_link;
1106
1107         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1108         if (!ret) {
1109                 ret = -ETIMEDOUT;
1110                 goto close_link;
1111         }
1112
1113         return 0;
1114
1115 close_link:
1116         /*
1117          * Send a close request to "undo" our open-ack. The close-ack will
1118          * release qcom_glink_send_open_req() reference and the last reference
1119          * will be relesed after receiving remote_close or transport unregister
1120          * by calling qcom_glink_native_remove().
1121          */
1122         qcom_glink_send_close_req(glink, channel);
1123
1124         return ret;
1125 }
1126
1127 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1128                                                     rpmsg_rx_cb_t cb,
1129                                                     void *priv,
1130                                                     struct rpmsg_channel_info
1131                                                                         chinfo)
1132 {
1133         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1134         struct glink_channel *channel;
1135         struct qcom_glink *glink = parent->glink;
1136         struct rpmsg_endpoint *ept;
1137         const char *name = chinfo.name;
1138         int cid;
1139         int ret;
1140         unsigned long flags;
1141
1142         spin_lock_irqsave(&glink->idr_lock, flags);
1143         idr_for_each_entry(&glink->rcids, channel, cid) {
1144                 if (!strcmp(channel->name, name))
1145                         break;
1146         }
1147         spin_unlock_irqrestore(&glink->idr_lock, flags);
1148
1149         if (!channel) {
1150                 channel = qcom_glink_create_local(glink, name);
1151                 if (IS_ERR(channel))
1152                         return NULL;
1153         } else {
1154                 ret = qcom_glink_create_remote(glink, channel);
1155                 if (ret)
1156                         return NULL;
1157         }
1158
1159         ept = &channel->ept;
1160         ept->rpdev = rpdev;
1161         ept->cb = cb;
1162         ept->priv = priv;
1163         ept->ops = &glink_endpoint_ops;
1164
1165         return ept;
1166 }
1167
1168 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1169 {
1170         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1171         struct device_node *np = rpdev->dev.of_node;
1172         struct qcom_glink *glink = channel->glink;
1173         struct glink_core_rx_intent *intent;
1174         const struct property *prop = NULL;
1175         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1176         int num_intents;
1177         int num_groups = 1;
1178         __be32 *val = defaults;
1179         int size;
1180
1181         if (glink->intentless || !completion_done(&channel->open_ack))
1182                 return 0;
1183
1184         prop = of_find_property(np, "qcom,intents", NULL);
1185         if (prop) {
1186                 val = prop->value;
1187                 num_groups = prop->length / sizeof(u32) / 2;
1188         }
1189
1190         /* Channel is now open, advertise base set of intents */
1191         while (num_groups--) {
1192                 size = be32_to_cpup(val++);
1193                 num_intents = be32_to_cpup(val++);
1194                 while (num_intents--) {
1195                         intent = qcom_glink_alloc_intent(glink, channel, size,
1196                                                          true);
1197                         if (!intent)
1198                                 break;
1199
1200                         qcom_glink_advertise_intent(glink, channel, intent);
1201                 }
1202         }
1203         return 0;
1204 }
1205
1206 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1207 {
1208         struct glink_channel *channel = to_glink_channel(ept);
1209         struct qcom_glink *glink = channel->glink;
1210         unsigned long flags;
1211
1212         spin_lock_irqsave(&channel->recv_lock, flags);
1213         channel->ept.cb = NULL;
1214         spin_unlock_irqrestore(&channel->recv_lock, flags);
1215
1216         /* Decouple the potential rpdev from the channel */
1217         channel->rpdev = NULL;
1218
1219         qcom_glink_send_close_req(glink, channel);
1220 }
1221
1222 static int qcom_glink_request_intent(struct qcom_glink *glink,
1223                                      struct glink_channel *channel,
1224                                      size_t size)
1225 {
1226         struct {
1227                 u16 id;
1228                 u16 cid;
1229                 u32 size;
1230         } __packed cmd;
1231
1232         int ret;
1233
1234         mutex_lock(&channel->intent_req_lock);
1235
1236         reinit_completion(&channel->intent_req_comp);
1237
1238         cmd.id = RPM_CMD_RX_INTENT_REQ;
1239         cmd.cid = channel->lcid;
1240         cmd.size = size;
1241
1242         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1243         if (ret)
1244                 goto unlock;
1245
1246         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1247         if (!ret) {
1248                 dev_err(glink->dev, "intent request timed out\n");
1249                 ret = -ETIMEDOUT;
1250         } else {
1251                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1252         }
1253
1254 unlock:
1255         mutex_unlock(&channel->intent_req_lock);
1256         return ret;
1257 }
1258
1259 static int __qcom_glink_send(struct glink_channel *channel,
1260                              void *data, int len, bool wait)
1261 {
1262         struct qcom_glink *glink = channel->glink;
1263         struct glink_core_rx_intent *intent = NULL;
1264         struct glink_core_rx_intent *tmp;
1265         int iid = 0;
1266         struct {
1267                 struct glink_msg msg;
1268                 __le32 chunk_size;
1269                 __le32 left_size;
1270         } __packed req;
1271         int ret;
1272         unsigned long flags;
1273
1274         if (!glink->intentless) {
1275                 while (!intent) {
1276                         spin_lock_irqsave(&channel->intent_lock, flags);
1277                         idr_for_each_entry(&channel->riids, tmp, iid) {
1278                                 if (tmp->size >= len && !tmp->in_use) {
1279                                         if (!intent)
1280                                                 intent = tmp;
1281                                         else if (intent->size > tmp->size)
1282                                                 intent = tmp;
1283                                         if (intent->size == len)
1284                                                 break;
1285                                 }
1286                         }
1287                         if (intent)
1288                                 intent->in_use = true;
1289                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1290
1291                         /* We found an available intent */
1292                         if (intent)
1293                                 break;
1294
1295                         if (!wait)
1296                                 return -EBUSY;
1297
1298                         ret = qcom_glink_request_intent(glink, channel, len);
1299                         if (ret < 0)
1300                                 return ret;
1301                 }
1302
1303                 iid = intent->id;
1304         }
1305
1306         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1307         req.msg.param1 = cpu_to_le16(channel->lcid);
1308         req.msg.param2 = cpu_to_le32(iid);
1309         req.chunk_size = cpu_to_le32(len);
1310         req.left_size = cpu_to_le32(0);
1311
1312         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1313
1314         /* Mark intent available if we failed */
1315         if (ret && intent)
1316                 intent->in_use = false;
1317
1318         return ret;
1319 }
1320
1321 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1322 {
1323         struct glink_channel *channel = to_glink_channel(ept);
1324
1325         return __qcom_glink_send(channel, data, len, true);
1326 }
1327
1328 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1329 {
1330         struct glink_channel *channel = to_glink_channel(ept);
1331
1332         return __qcom_glink_send(channel, data, len, false);
1333 }
1334
1335 /*
1336  * Finds the device_node for the glink child interested in this channel.
1337  */
1338 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1339                                                     const char *channel)
1340 {
1341         struct device_node *child;
1342         const char *name;
1343         const char *key;
1344         int ret;
1345
1346         for_each_available_child_of_node(node, child) {
1347                 key = "qcom,glink-channels";
1348                 ret = of_property_read_string(child, key, &name);
1349                 if (ret)
1350                         continue;
1351
1352                 if (strcmp(name, channel) == 0)
1353                         return child;
1354         }
1355
1356         return NULL;
1357 }
1358
1359 static const struct rpmsg_device_ops glink_device_ops = {
1360         .create_ept = qcom_glink_create_ept,
1361         .announce_create = qcom_glink_announce_create,
1362 };
1363
1364 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1365         .destroy_ept = qcom_glink_destroy_ept,
1366         .send = qcom_glink_send,
1367         .trysend = qcom_glink_trysend,
1368 };
1369
1370 static void qcom_glink_rpdev_release(struct device *dev)
1371 {
1372         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1373         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1374
1375         channel->rpdev = NULL;
1376         kfree(rpdev);
1377 }
1378
1379 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1380                               char *name)
1381 {
1382         struct glink_channel *channel;
1383         struct rpmsg_device *rpdev;
1384         bool create_device = false;
1385         struct device_node *node;
1386         int lcid;
1387         int ret;
1388         unsigned long flags;
1389
1390         spin_lock_irqsave(&glink->idr_lock, flags);
1391         idr_for_each_entry(&glink->lcids, channel, lcid) {
1392                 if (!strcmp(channel->name, name))
1393                         break;
1394         }
1395         spin_unlock_irqrestore(&glink->idr_lock, flags);
1396
1397         if (!channel) {
1398                 channel = qcom_glink_alloc_channel(glink, name);
1399                 if (IS_ERR(channel))
1400                         return PTR_ERR(channel);
1401
1402                 /* The opening dance was initiated by the remote */
1403                 create_device = true;
1404         }
1405
1406         spin_lock_irqsave(&glink->idr_lock, flags);
1407         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1408         if (ret < 0) {
1409                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1410                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1411                 goto free_channel;
1412         }
1413         channel->rcid = ret;
1414         spin_unlock_irqrestore(&glink->idr_lock, flags);
1415
1416         complete_all(&channel->open_req);
1417
1418         if (create_device) {
1419                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1420                 if (!rpdev) {
1421                         ret = -ENOMEM;
1422                         goto rcid_remove;
1423                 }
1424
1425                 rpdev->ept = &channel->ept;
1426                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1427                 rpdev->src = RPMSG_ADDR_ANY;
1428                 rpdev->dst = RPMSG_ADDR_ANY;
1429                 rpdev->ops = &glink_device_ops;
1430
1431                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1432                 rpdev->dev.of_node = node;
1433                 rpdev->dev.parent = glink->dev;
1434                 rpdev->dev.release = qcom_glink_rpdev_release;
1435
1436                 ret = rpmsg_register_device(rpdev);
1437                 if (ret)
1438                         goto rcid_remove;
1439
1440                 channel->rpdev = rpdev;
1441         }
1442
1443         return 0;
1444
1445 rcid_remove:
1446         spin_lock_irqsave(&glink->idr_lock, flags);
1447         idr_remove(&glink->rcids, channel->rcid);
1448         channel->rcid = 0;
1449         spin_unlock_irqrestore(&glink->idr_lock, flags);
1450 free_channel:
1451         /* Release the reference, iff we took it */
1452         if (create_device)
1453                 kref_put(&channel->refcount, qcom_glink_channel_release);
1454
1455         return ret;
1456 }
1457
1458 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1459 {
1460         struct rpmsg_channel_info chinfo;
1461         struct glink_channel *channel;
1462         unsigned long flags;
1463
1464         spin_lock_irqsave(&glink->idr_lock, flags);
1465         channel = idr_find(&glink->rcids, rcid);
1466         spin_unlock_irqrestore(&glink->idr_lock, flags);
1467         if (WARN(!channel, "close request on unknown channel\n"))
1468                 return;
1469
1470         /* cancel pending rx_done work */
1471         cancel_work_sync(&channel->intent_work);
1472
1473         if (channel->rpdev) {
1474                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1475                 chinfo.src = RPMSG_ADDR_ANY;
1476                 chinfo.dst = RPMSG_ADDR_ANY;
1477
1478                 rpmsg_unregister_device(glink->dev, &chinfo);
1479         }
1480
1481         qcom_glink_send_close_ack(glink, channel->rcid);
1482
1483         spin_lock_irqsave(&glink->idr_lock, flags);
1484         idr_remove(&glink->rcids, channel->rcid);
1485         channel->rcid = 0;
1486         spin_unlock_irqrestore(&glink->idr_lock, flags);
1487
1488         kref_put(&channel->refcount, qcom_glink_channel_release);
1489 }
1490
1491 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1492 {
1493         struct glink_channel *channel;
1494         unsigned long flags;
1495
1496         spin_lock_irqsave(&glink->idr_lock, flags);
1497         channel = idr_find(&glink->lcids, lcid);
1498         if (WARN(!channel, "close ack on unknown channel\n")) {
1499                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1500                 return;
1501         }
1502
1503         idr_remove(&glink->lcids, channel->lcid);
1504         channel->lcid = 0;
1505         spin_unlock_irqrestore(&glink->idr_lock, flags);
1506
1507         kref_put(&channel->refcount, qcom_glink_channel_release);
1508 }
1509
1510 static void qcom_glink_work(struct work_struct *work)
1511 {
1512         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1513                                                 rx_work);
1514         struct glink_defer_cmd *dcmd;
1515         struct glink_msg *msg;
1516         unsigned long flags;
1517         unsigned int param1;
1518         unsigned int param2;
1519         unsigned int cmd;
1520
1521         for (;;) {
1522                 spin_lock_irqsave(&glink->rx_lock, flags);
1523                 if (list_empty(&glink->rx_queue)) {
1524                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1525                         break;
1526                 }
1527                 dcmd = list_first_entry(&glink->rx_queue,
1528                                         struct glink_defer_cmd, node);
1529                 list_del(&dcmd->node);
1530                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1531
1532                 msg = &dcmd->msg;
1533                 cmd = le16_to_cpu(msg->cmd);
1534                 param1 = le16_to_cpu(msg->param1);
1535                 param2 = le32_to_cpu(msg->param2);
1536
1537                 switch (cmd) {
1538                 case RPM_CMD_VERSION:
1539                         qcom_glink_receive_version(glink, param1, param2);
1540                         break;
1541                 case RPM_CMD_VERSION_ACK:
1542                         qcom_glink_receive_version_ack(glink, param1, param2);
1543                         break;
1544                 case RPM_CMD_OPEN:
1545                         qcom_glink_rx_open(glink, param1, msg->data);
1546                         break;
1547                 case RPM_CMD_CLOSE:
1548                         qcom_glink_rx_close(glink, param1);
1549                         break;
1550                 case RPM_CMD_CLOSE_ACK:
1551                         qcom_glink_rx_close_ack(glink, param1);
1552                         break;
1553                 case RPM_CMD_RX_INTENT_REQ:
1554                         qcom_glink_handle_intent_req(glink, param1, param2);
1555                         break;
1556                 default:
1557                         WARN(1, "Unknown defer object %d\n", cmd);
1558                         break;
1559                 }
1560
1561                 kfree(dcmd);
1562         }
1563 }
1564
1565 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1566 {
1567         struct glink_defer_cmd *dcmd;
1568         struct glink_defer_cmd *tmp;
1569
1570         /* cancel any pending deferred rx_work */
1571         cancel_work_sync(&glink->rx_work);
1572
1573         list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1574                 kfree(dcmd);
1575 }
1576
1577 static ssize_t rpmsg_name_show(struct device *dev,
1578                                struct device_attribute *attr, char *buf)
1579 {
1580         int ret = 0;
1581         const char *name;
1582
1583         ret = of_property_read_string(dev->of_node, "label", &name);
1584         if (ret < 0)
1585                 name = dev->of_node->name;
1586
1587         return snprintf(buf, RPMSG_NAME_SIZE, "%s\n", name);
1588 }
1589 static DEVICE_ATTR_RO(rpmsg_name);
1590
1591 static struct attribute *qcom_glink_attrs[] = {
1592         &dev_attr_rpmsg_name.attr,
1593         NULL
1594 };
1595 ATTRIBUTE_GROUPS(qcom_glink);
1596
1597 static void qcom_glink_device_release(struct device *dev)
1598 {
1599         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1600         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1601
1602         /* Release qcom_glink_alloc_channel() reference */
1603         kref_put(&channel->refcount, qcom_glink_channel_release);
1604         kfree(rpdev);
1605 }
1606
1607 static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1608 {
1609         struct rpmsg_device *rpdev;
1610         struct glink_channel *channel;
1611
1612         rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1613         if (!rpdev)
1614                 return -ENOMEM;
1615
1616         channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1617         if (IS_ERR(channel)) {
1618                 kfree(rpdev);
1619                 return PTR_ERR(channel);
1620         }
1621         channel->rpdev = rpdev;
1622
1623         rpdev->ept = &channel->ept;
1624         rpdev->ops = &glink_device_ops;
1625         rpdev->dev.parent = glink->dev;
1626         rpdev->dev.release = qcom_glink_device_release;
1627
1628         return rpmsg_chrdev_register_device(rpdev);
1629 }
1630
1631 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1632                                            unsigned long features,
1633                                            struct qcom_glink_pipe *rx,
1634                                            struct qcom_glink_pipe *tx,
1635                                            bool intentless)
1636 {
1637         int irq;
1638         int ret;
1639         struct qcom_glink *glink;
1640
1641         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1642         if (!glink)
1643                 return ERR_PTR(-ENOMEM);
1644
1645         glink->dev = dev;
1646         glink->tx_pipe = tx;
1647         glink->rx_pipe = rx;
1648
1649         glink->features = features;
1650         glink->intentless = intentless;
1651
1652         spin_lock_init(&glink->tx_lock);
1653         spin_lock_init(&glink->rx_lock);
1654         INIT_LIST_HEAD(&glink->rx_queue);
1655         INIT_WORK(&glink->rx_work, qcom_glink_work);
1656
1657         spin_lock_init(&glink->idr_lock);
1658         idr_init(&glink->lcids);
1659         idr_init(&glink->rcids);
1660
1661         glink->dev->groups = qcom_glink_groups;
1662
1663         ret = device_add_groups(dev, qcom_glink_groups);
1664         if (ret)
1665                 dev_err(dev, "failed to add groups\n");
1666
1667         ret = of_property_read_string(dev->of_node, "label", &glink->name);
1668         if (ret < 0)
1669                 glink->name = dev->of_node->name;
1670
1671         glink->mbox_client.dev = dev;
1672         glink->mbox_client.knows_txdone = true;
1673         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1674         if (IS_ERR(glink->mbox_chan)) {
1675                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1676                         dev_err(dev, "failed to acquire IPC channel\n");
1677                 return ERR_CAST(glink->mbox_chan);
1678         }
1679
1680         irq = of_irq_get(dev->of_node, 0);
1681         ret = devm_request_irq(dev, irq,
1682                                qcom_glink_native_intr,
1683                                IRQF_NO_SUSPEND | IRQF_SHARED,
1684                                "glink-native", glink);
1685         if (ret) {
1686                 dev_err(dev, "failed to request IRQ\n");
1687                 return ERR_PTR(ret);
1688         }
1689
1690         glink->irq = irq;
1691
1692         ret = qcom_glink_send_version(glink);
1693         if (ret)
1694                 return ERR_PTR(ret);
1695
1696         ret = qcom_glink_create_chrdev(glink);
1697         if (ret)
1698                 dev_err(glink->dev, "failed to register chrdev\n");
1699
1700         return glink;
1701 }
1702 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1703
1704 static int qcom_glink_remove_device(struct device *dev, void *data)
1705 {
1706         device_unregister(dev);
1707
1708         return 0;
1709 }
1710
1711 void qcom_glink_native_remove(struct qcom_glink *glink)
1712 {
1713         struct glink_channel *channel;
1714         int cid;
1715         int ret;
1716
1717         disable_irq(glink->irq);
1718         qcom_glink_cancel_rx_work(glink);
1719
1720         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1721         if (ret)
1722                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1723
1724         /* Release any defunct local channels, waiting for close-ack */
1725         idr_for_each_entry(&glink->lcids, channel, cid)
1726                 kref_put(&channel->refcount, qcom_glink_channel_release);
1727
1728         /* Release any defunct local channels, waiting for close-req */
1729         idr_for_each_entry(&glink->rcids, channel, cid)
1730                 kref_put(&channel->refcount, qcom_glink_channel_release);
1731
1732         idr_destroy(&glink->lcids);
1733         idr_destroy(&glink->rcids);
1734         mbox_free_channel(glink->mbox_chan);
1735 }
1736 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1737
1738 void qcom_glink_native_unregister(struct qcom_glink *glink)
1739 {
1740         device_unregister(glink->dev);
1741 }
1742 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1743
1744 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1745 MODULE_LICENSE("GPL v2");