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