drivers/net/wwan/iosm/iosm_ipc_mux_codec.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2020-21 Intel Corporation.
   4  */
   5
   6 #include <linux/nospec.h>
   7
   8 #include "iosm_ipc_imem_ops.h"
   9 #include "iosm_ipc_mux_codec.h"
  10 #include "iosm_ipc_task_queue.h"
  11
  12 /* Test the link power state and send a MUX command in blocking mode. */
  13 static int ipc_mux_tq_cmd_send(struct iosm_imem *ipc_imem, int arg, void *msg,
  14                                size_t size)
  15 {
  16         struct iosm_mux *ipc_mux = ipc_imem->mux;
  17         const struct mux_acb *acb = msg;
  18
  19         skb_queue_tail(&ipc_mux->channel->ul_list, acb->skb);
  20         ipc_imem_ul_send(ipc_mux->imem);
  21
  22         return 0;
  23 }
  24
  25 static int ipc_mux_acb_send(struct iosm_mux *ipc_mux, bool blocking)
  26 {
  27         struct completion *completion = &ipc_mux->channel->ul_sem;
  28         int ret = ipc_task_queue_send_task(ipc_mux->imem, ipc_mux_tq_cmd_send,
  29                                            0, &ipc_mux->acb,
  30                                            sizeof(ipc_mux->acb), false);
  31         if (ret) {
  32                 dev_err(ipc_mux->dev, "unable to send mux command");
  33                 return ret;
  34         }
  35
  36         /* if blocking, suspend the app and wait for irq in the flash or
  37          * crash phase. return false on timeout to indicate failure.
  38          */
  39         if (blocking) {
  40                 u32 wait_time_milliseconds = IPC_MUX_CMD_RUN_DEFAULT_TIMEOUT;
  41
  42                 reinit_completion(completion);
  43
  44                 if (wait_for_completion_interruptible_timeout
  45                    (completion, msecs_to_jiffies(wait_time_milliseconds)) ==
  46                    0) {
  47                         dev_err(ipc_mux->dev, "ch[%d] timeout",
  48                                 ipc_mux->channel_id);
  49                         ipc_uevent_send(ipc_mux->imem->dev, UEVENT_MDM_TIMEOUT);
  50                         return -ETIMEDOUT;
  51                 }
  52         }
  53
  54         return 0;
  55 }
  56
  57 /* Prepare mux Command */
  58 static struct mux_lite_cmdh *ipc_mux_lite_add_cmd(struct iosm_mux *ipc_mux,
  59                                                   u32 cmd, struct mux_acb *acb,
  60                                                   void *param, u32 param_size)
  61 {
  62         struct mux_lite_cmdh *cmdh = (struct mux_lite_cmdh *)acb->skb->data;
  63
  64         cmdh->signature = cpu_to_le32(MUX_SIG_CMDH);
  65         cmdh->command_type = cpu_to_le32(cmd);
  66         cmdh->if_id = acb->if_id;
  67
  68         acb->cmd = cmd;
  69
  70         cmdh->cmd_len = cpu_to_le16(offsetof(struct mux_lite_cmdh, param) +
  71                                     param_size);
  72         cmdh->transaction_id = cpu_to_le32(ipc_mux->tx_transaction_id++);
  73
  74         if (param)
  75                 memcpy(&cmdh->param, param, param_size);
  76
  77         skb_put(acb->skb, le16_to_cpu(cmdh->cmd_len));
  78
  79         return cmdh;
  80 }
  81
  82 static int ipc_mux_acb_alloc(struct iosm_mux *ipc_mux)
  83 {
  84         struct mux_acb *acb = &ipc_mux->acb;
  85         struct sk_buff *skb;
  86         dma_addr_t mapping;
  87
  88         /* Allocate skb memory for the uplink buffer. */
  89         skb = ipc_pcie_alloc_skb(ipc_mux->pcie, MUX_MAX_UL_ACB_BUF_SIZE,
  90                                  GFP_ATOMIC, &mapping, DMA_TO_DEVICE, 0);
  91         if (!skb)
  92                 return -ENOMEM;
  93
  94         /* Save the skb address. */
  95         acb->skb = skb;
  96
  97         memset(skb->data, 0, MUX_MAX_UL_ACB_BUF_SIZE);
  98
  99         return 0;
 100 }
 101
 102 int ipc_mux_dl_acb_send_cmds(struct iosm_mux *ipc_mux, u32 cmd_type, u8 if_id,
 103                              u32 transaction_id, union mux_cmd_param *param,
 104                              size_t res_size, bool blocking, bool respond)
 105 {
 106         struct mux_acb *acb = &ipc_mux->acb;
 107         struct mux_lite_cmdh *ack_lite;
 108         int ret = 0;
 109
 110         acb->if_id = if_id;
 111         ret = ipc_mux_acb_alloc(ipc_mux);
 112         if (ret)
 113                 return ret;
 114
 115         ack_lite = ipc_mux_lite_add_cmd(ipc_mux, cmd_type, acb, param,
 116                                         res_size);
 117         if (respond)
 118                 ack_lite->transaction_id = cpu_to_le32(transaction_id);
 119
 120         ret = ipc_mux_acb_send(ipc_mux, blocking);
 121
 122         return ret;
 123 }
 124
 125 void ipc_mux_netif_tx_flowctrl(struct mux_session *session, int idx, bool on)
 126 {
 127         /* Inform the network interface to start/stop flow ctrl */
 128         ipc_wwan_tx_flowctrl(session->wwan, idx, on);
 129 }
 130
 131 static int ipc_mux_dl_cmdresps_decode_process(struct iosm_mux *ipc_mux,
 132                                               struct mux_lite_cmdh *cmdh)
 133 {
 134         struct mux_acb *acb = &ipc_mux->acb;
 135
 136         switch (le32_to_cpu(cmdh->command_type)) {
 137         case MUX_CMD_OPEN_SESSION_RESP:
 138         case MUX_CMD_CLOSE_SESSION_RESP:
 139                 /* Resume the control application. */
 140                 acb->got_param = cmdh->param;
 141                 break;
 142
 143         case MUX_LITE_CMD_FLOW_CTL_ACK:
 144                 /* This command type is not expected as response for
 145                  * Aggregation version of the protocol. So return non-zero.
 146                  */
 147                 if (ipc_mux->protocol != MUX_LITE)
 148                         return -EINVAL;
 149
 150                 dev_dbg(ipc_mux->dev, "if %u FLOW_CTL_ACK %u received",
 151                         cmdh->if_id, le32_to_cpu(cmdh->transaction_id));
 152                 break;
 153
 154         default:
 155                 return -EINVAL;
 156         }
 157
 158         acb->wanted_response = MUX_CMD_INVALID;
 159         acb->got_response = le32_to_cpu(cmdh->command_type);
 160         complete(&ipc_mux->channel->ul_sem);
 161
 162         return 0;
 163 }
 164
 165 static int ipc_mux_dl_dlcmds_decode_process(struct iosm_mux *ipc_mux,
 166                                             struct mux_lite_cmdh *cmdh)
 167 {
 168         union mux_cmd_param *param = &cmdh->param;
 169         struct mux_session *session;
 170         int new_size;
 171
 172         dev_dbg(ipc_mux->dev, "if_id[%d]: dlcmds decode process %d",
 173                 cmdh->if_id, le32_to_cpu(cmdh->command_type));
 174
 175         switch (le32_to_cpu(cmdh->command_type)) {
 176         case MUX_LITE_CMD_FLOW_CTL:
 177
 178                 if (cmdh->if_id >= ipc_mux->nr_sessions) {
 179                         dev_err(ipc_mux->dev, "if_id [%d] not valid",
 180                                 cmdh->if_id);
 181                         return -EINVAL; /* No session interface id. */
 182                 }
 183
 184                 session = &ipc_mux->session[cmdh->if_id];
 185
 186                 new_size = offsetof(struct mux_lite_cmdh, param) +
 187                            sizeof(param->flow_ctl);
 188                 if (param->flow_ctl.mask == cpu_to_le32(0xFFFFFFFF)) {
 189                         /* Backward Compatibility */
 190                         if (cmdh->cmd_len == cpu_to_le16(new_size))
 191                                 session->flow_ctl_mask =
 192                                         le32_to_cpu(param->flow_ctl.mask);
 193                         else
 194                                 session->flow_ctl_mask = ~0;
 195                         /* if CP asks for FLOW CTRL Enable
 196                          * then set our internal flow control Tx flag
 197                          * to limit uplink session queueing
 198                          */
 199                         session->net_tx_stop = true;
 200                         /* Update the stats */
 201                         session->flow_ctl_en_cnt++;
 202                 } else if (param->flow_ctl.mask == 0) {
 203                         /* Just reset the Flow control mask and let
 204                          * mux_flow_ctrl_low_thre_b take control on
 205                          * our internal Tx flag and enabling kernel
 206                          * flow control
 207                          */
 208                         /* Backward Compatibility */
 209                         if (cmdh->cmd_len == cpu_to_le16(new_size))
 210                                 session->flow_ctl_mask =
 211                                         le32_to_cpu(param->flow_ctl.mask);
 212                         else
 213                                 session->flow_ctl_mask = 0;
 214                         /* Update the stats */
 215                         session->flow_ctl_dis_cnt++;
 216                 } else {
 217                         break;
 218                 }
 219
 220                 dev_dbg(ipc_mux->dev, "if[%u] FLOW CTRL 0x%08X", cmdh->if_id,
 221                         le32_to_cpu(param->flow_ctl.mask));
 222                 break;
 223
 224         case MUX_LITE_CMD_LINK_STATUS_REPORT:
 225                 break;
 226
 227         default:
 228                 return -EINVAL;
 229         }
 230         return 0;
 231 }
 232
 233 /* Decode and Send appropriate response to a command block. */
 234 static void ipc_mux_dl_cmd_decode(struct iosm_mux *ipc_mux, struct sk_buff *skb)
 235 {
 236         struct mux_lite_cmdh *cmdh = (struct mux_lite_cmdh *)skb->data;
 237         __le32 trans_id = cmdh->transaction_id;
 238
 239         if (ipc_mux_dl_cmdresps_decode_process(ipc_mux, cmdh)) {
 240                 /* Unable to decode command response indicates the cmd_type
 241                  * may be a command instead of response. So try to decoding it.
 242                  */
 243                 if (!ipc_mux_dl_dlcmds_decode_process(ipc_mux, cmdh)) {
 244                         /* Decoded command may need a response. Give the
 245                          * response according to the command type.
 246                          */
 247                         union mux_cmd_param *mux_cmd = NULL;
 248                         size_t size = 0;
 249                         u32 cmd = MUX_LITE_CMD_LINK_STATUS_REPORT_RESP;
 250
 251                         if (cmdh->command_type ==
 252                             cpu_to_le32(MUX_LITE_CMD_LINK_STATUS_REPORT)) {
 253                                 mux_cmd = &cmdh->param;
 254                                 mux_cmd->link_status_resp.response =
 255                                         cpu_to_le32(MUX_CMD_RESP_SUCCESS);
 256                                 /* response field is u32 */
 257                                 size = sizeof(u32);
 258                         } else if (cmdh->command_type ==
 259                                    cpu_to_le32(MUX_LITE_CMD_FLOW_CTL)) {
 260                                 cmd = MUX_LITE_CMD_FLOW_CTL_ACK;
 261                         } else {
 262                                 return;
 263                         }
 264
 265                         if (ipc_mux_dl_acb_send_cmds(ipc_mux, cmd, cmdh->if_id,
 266                                                      le32_to_cpu(trans_id),
 267                                                      mux_cmd, size, false,
 268                                                      true))
 269                                 dev_err(ipc_mux->dev,
 270                                         "if_id %d: cmd send failed",
 271                                         cmdh->if_id);
 272                 }
 273         }
 274 }
 275
 276 /* Pass the DL packet to the netif layer. */
 277 static int ipc_mux_net_receive(struct iosm_mux *ipc_mux, int if_id,
 278                                struct iosm_wwan *wwan, u32 offset,
 279                                u8 service_class, struct sk_buff *skb)
 280 {
 281         struct sk_buff *dest_skb = skb_clone(skb, GFP_ATOMIC);
 282
 283         if (!dest_skb)
 284                 return -ENOMEM;
 285
 286         skb_pull(dest_skb, offset);
 287         skb_set_tail_pointer(dest_skb, dest_skb->len);
 288         /* Pass the packet to the netif layer. */
 289         dest_skb->priority = service_class;
 290
 291         return ipc_wwan_receive(wwan, dest_skb, false, if_id + 1);
 292 }
 293
 294 /* Decode Flow Credit Table in the block */
 295 static void ipc_mux_dl_fcth_decode(struct iosm_mux *ipc_mux,
 296                                    unsigned char *block)
 297 {
 298         struct ipc_mem_lite_gen_tbl *fct = (struct ipc_mem_lite_gen_tbl *)block;
 299         struct iosm_wwan *wwan;
 300         int ul_credits;
 301         int if_id;
 302
 303         if (fct->vfl_length != sizeof(fct->vfl.nr_of_bytes)) {
 304                 dev_err(ipc_mux->dev, "unexpected FCT length: %d",
 305                         fct->vfl_length);
 306                 return;
 307         }
 308
 309         if_id = fct->if_id;
 310         if (if_id >= ipc_mux->nr_sessions) {
 311                 dev_err(ipc_mux->dev, "not supported if_id: %d", if_id);
 312                 return;
 313         }
 314
 315         /* Is the session active ? */
 316         if_id = array_index_nospec(if_id, ipc_mux->nr_sessions);
 317         wwan = ipc_mux->session[if_id].wwan;
 318         if (!wwan) {
 319                 dev_err(ipc_mux->dev, "session Net ID is NULL");
 320                 return;
 321         }
 322
 323         ul_credits = fct->vfl.nr_of_bytes;
 324
 325         dev_dbg(ipc_mux->dev, "Flow_Credit:: if_id[%d] Old: %d Grants: %d",
 326                 if_id, ipc_mux->session[if_id].ul_flow_credits, ul_credits);
 327
 328         /* Update the Flow Credit information from ADB */
 329         ipc_mux->session[if_id].ul_flow_credits += ul_credits;
 330
 331         /* Check whether the TX can be started */
 332         if (ipc_mux->session[if_id].ul_flow_credits > 0) {
 333                 ipc_mux->session[if_id].net_tx_stop = false;
 334                 ipc_mux_netif_tx_flowctrl(&ipc_mux->session[if_id],
 335                                           ipc_mux->session[if_id].if_id, false);
 336         }
 337 }
 338
 339 /* Decode non-aggregated datagram */
 340 static void ipc_mux_dl_adgh_decode(struct iosm_mux *ipc_mux,
 341                                    struct sk_buff *skb)
 342 {
 343         u32 pad_len, packet_offset;
 344         struct iosm_wwan *wwan;
 345         struct mux_adgh *adgh;
 346         u8 *block = skb->data;
 347         int rc = 0;
 348         u8 if_id;
 349
 350         adgh = (struct mux_adgh *)block;
 351
 352         if (adgh->signature != cpu_to_le32(MUX_SIG_ADGH)) {
 353                 dev_err(ipc_mux->dev, "invalid ADGH signature received");
 354                 return;
 355         }
 356
 357         if_id = adgh->if_id;
 358         if (if_id >= ipc_mux->nr_sessions) {
 359                 dev_err(ipc_mux->dev, "invalid if_id while decoding %d", if_id);
 360                 return;
 361         }
 362
 363         /* Is the session active ? */
 364         if_id = array_index_nospec(if_id, ipc_mux->nr_sessions);
 365         wwan = ipc_mux->session[if_id].wwan;
 366         if (!wwan) {
 367                 dev_err(ipc_mux->dev, "session Net ID is NULL");
 368                 return;
 369         }
 370
 371         /* Store the pad len for the corresponding session
 372          * Pad bytes as negotiated in the open session less the header size
 373          * (see session management chapter for details).
 374          * If resulting padding is zero or less, the additional head padding is
 375          * omitted. For e.g., if HEAD_PAD_LEN = 16 or less, this field is
 376          * omitted if HEAD_PAD_LEN = 20, then this field will have 4 bytes
 377          * set to zero
 378          */
 379         pad_len =
 380                 ipc_mux->session[if_id].dl_head_pad_len - IPC_MEM_DL_ETH_OFFSET;
 381         packet_offset = sizeof(*adgh) + pad_len;
 382
 383         if_id += ipc_mux->wwan_q_offset;
 384
 385         /* Pass the packet to the netif layer */
 386         rc = ipc_mux_net_receive(ipc_mux, if_id, wwan, packet_offset,
 387                                  adgh->service_class, skb);
 388         if (rc) {
 389                 dev_err(ipc_mux->dev, "mux adgh decoding error");
 390                 return;
 391         }
 392         ipc_mux->session[if_id].flush = 1;
 393 }
 394
 395 void ipc_mux_dl_decode(struct iosm_mux *ipc_mux, struct sk_buff *skb)
 396 {
 397         u32 signature;
 398
 399         if (!skb->data)
 400                 return;
 401
 402         /* Decode the MUX header type. */
 403         signature = le32_to_cpup((__le32 *)skb->data);
 404
 405         switch (signature) {
 406         case MUX_SIG_ADGH:
 407                 ipc_mux_dl_adgh_decode(ipc_mux, skb);
 408                 break;
 409
 410         case MUX_SIG_FCTH:
 411                 ipc_mux_dl_fcth_decode(ipc_mux, skb->data);
 412                 break;
 413
 414         case MUX_SIG_CMDH:
 415                 ipc_mux_dl_cmd_decode(ipc_mux, skb);
 416                 break;
 417
 418         default:
 419                 dev_err(ipc_mux->dev, "invalid ABH signature");
 420         }
 421
 422         ipc_pcie_kfree_skb(ipc_mux->pcie, skb);
 423 }
 424
 425 static int ipc_mux_ul_skb_alloc(struct iosm_mux *ipc_mux,
 426                                 struct mux_adb *ul_adb, u32 type)
 427 {
 428         /* Take the first element of the free list. */
 429         struct sk_buff *skb = skb_dequeue(&ul_adb->free_list);
 430         int qlt_size;
 431
 432         if (!skb)
 433                 return -EBUSY; /* Wait for a free ADB skb. */
 434
 435         /* Mark it as UL ADB to select the right free operation. */
 436         IPC_CB(skb)->op_type = (u8)UL_MUX_OP_ADB;
 437
 438         switch (type) {
 439         case MUX_SIG_ADGH:
 440                 /* Save the ADB memory settings. */
 441                 ul_adb->dest_skb = skb;
 442                 ul_adb->buf = skb->data;
 443                 ul_adb->size = IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE;
 444                 /* reset statistic counter */
 445                 ul_adb->if_cnt = 0;
 446                 ul_adb->payload_size = 0;
 447                 ul_adb->dg_cnt_total = 0;
 448
 449                 ul_adb->adgh = (struct mux_adgh *)skb->data;
 450                 memset(ul_adb->adgh, 0, sizeof(struct mux_adgh));
 451                 break;
 452
 453         case MUX_SIG_QLTH:
 454                 qlt_size = offsetof(struct ipc_mem_lite_gen_tbl, vfl) +
 455                            (MUX_QUEUE_LEVEL * sizeof(struct mux_lite_vfl));
 456
 457                 if (qlt_size > IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE) {
 458                         dev_err(ipc_mux->dev,
 459                                 "can't support. QLT size:%d SKB size: %d",
 460                                 qlt_size, IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE);
 461                         return -ERANGE;
 462                 }
 463
 464                 ul_adb->qlth_skb = skb;
 465                 memset((ul_adb->qlth_skb)->data, 0, qlt_size);
 466                 skb_put(skb, qlt_size);
 467                 break;
 468         }
 469
 470         return 0;
 471 }
 472
 473 static void ipc_mux_ul_adgh_finish(struct iosm_mux *ipc_mux)
 474 {
 475         struct mux_adb *ul_adb = &ipc_mux->ul_adb;
 476         u16 adgh_len;
 477         long long bytes;
 478         char *str;
 479
 480         if (!ul_adb->dest_skb) {
 481                 dev_err(ipc_mux->dev, "no dest skb");
 482                 return;
 483         }
 484
 485         adgh_len = le16_to_cpu(ul_adb->adgh->length);
 486         skb_put(ul_adb->dest_skb, adgh_len);
 487         skb_queue_tail(&ipc_mux->channel->ul_list, ul_adb->dest_skb);
 488         ul_adb->dest_skb = NULL;
 489
 490         if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS) {
 491                 struct mux_session *session;
 492
 493                 session = &ipc_mux->session[ul_adb->adgh->if_id];
 494                 str = "available_credits";
 495                 bytes = (long long)session->ul_flow_credits;
 496
 497         } else {
 498                 str = "pend_bytes";
 499                 bytes = ipc_mux->ul_data_pend_bytes;
 500                 ipc_mux->ul_data_pend_bytes = ipc_mux->ul_data_pend_bytes +
 501                                               adgh_len;
 502         }
 503
 504         dev_dbg(ipc_mux->dev, "UL ADGH: size=%u, if_id=%d, payload=%d, %s=%lld",
 505                 adgh_len, ul_adb->adgh->if_id, ul_adb->payload_size,
 506                 str, bytes);
 507 }
 508
 509 /* Allocates an ADB from the free list and initializes it with ADBH  */
 510 static bool ipc_mux_ul_adb_allocate(struct iosm_mux *ipc_mux,
 511                                     struct mux_adb *adb, int *size_needed,
 512                                     u32 type)
 513 {
 514         bool ret_val = false;
 515         int status;
 516
 517         if (!adb->dest_skb) {
 518                 /* Allocate memory for the ADB including of the
 519                  * datagram table header.
 520                  */
 521                 status = ipc_mux_ul_skb_alloc(ipc_mux, adb, type);
 522                 if (status)
 523                         /* Is a pending ADB available ? */
 524                         ret_val = true; /* None. */
 525
 526                 /* Update size need to zero only for new ADB memory */
 527                 *size_needed = 0;
 528         }
 529
 530         return ret_val;
 531 }
 532
 533 /* Informs the network stack to stop sending further packets for all opened
 534  * sessions
 535  */
 536 static void ipc_mux_stop_tx_for_all_sessions(struct iosm_mux *ipc_mux)
 537 {
 538         struct mux_session *session;
 539         int idx;
 540
 541         for (idx = 0; idx < ipc_mux->nr_sessions; idx++) {
 542                 session = &ipc_mux->session[idx];
 543
 544                 if (!session->wwan)
 545                         continue;
 546
 547                 session->net_tx_stop = true;
 548         }
 549 }
 550
 551 /* Sends Queue Level Table of all opened sessions */
 552 static bool ipc_mux_lite_send_qlt(struct iosm_mux *ipc_mux)
 553 {
 554         struct ipc_mem_lite_gen_tbl *qlt;
 555         struct mux_session *session;
 556         bool qlt_updated = false;
 557         int i;
 558         int qlt_size;
 559
 560         if (!ipc_mux->initialized || ipc_mux->state != MUX_S_ACTIVE)
 561                 return qlt_updated;
 562
 563         qlt_size = offsetof(struct ipc_mem_lite_gen_tbl, vfl) +
 564                    MUX_QUEUE_LEVEL * sizeof(struct mux_lite_vfl);
 565
 566         for (i = 0; i < ipc_mux->nr_sessions; i++) {
 567                 session = &ipc_mux->session[i];
 568
 569                 if (!session->wwan || session->flow_ctl_mask)
 570                         continue;
 571
 572                 if (ipc_mux_ul_skb_alloc(ipc_mux, &ipc_mux->ul_adb,
 573                                          MUX_SIG_QLTH)) {
 574                         dev_err(ipc_mux->dev,
 575                                 "no reserved mem to send QLT of if_id: %d", i);
 576                         break;
 577                 }
 578
 579                 /* Prepare QLT */
 580                 qlt = (struct ipc_mem_lite_gen_tbl *)(ipc_mux->ul_adb.qlth_skb)
 581                               ->data;
 582                 qlt->signature = cpu_to_le32(MUX_SIG_QLTH);
 583                 qlt->length = cpu_to_le16(qlt_size);
 584                 qlt->if_id = i;
 585                 qlt->vfl_length = MUX_QUEUE_LEVEL * sizeof(struct mux_lite_vfl);
 586                 qlt->reserved[0] = 0;
 587                 qlt->reserved[1] = 0;
 588
 589                 qlt->vfl.nr_of_bytes = session->ul_list.qlen;
 590
 591                 /* Add QLT to the transfer list. */
 592                 skb_queue_tail(&ipc_mux->channel->ul_list,
 593                                ipc_mux->ul_adb.qlth_skb);
 594
 595                 qlt_updated = true;
 596                 ipc_mux->ul_adb.qlth_skb = NULL;
 597         }
 598
 599         if (qlt_updated)
 600                 /* Updates the TDs with ul_list */
 601                 (void)ipc_imem_ul_write_td(ipc_mux->imem);
 602
 603         return qlt_updated;
 604 }
 605
 606 /* Checks the available credits for the specified session and returns
 607  * number of packets for which credits are available.
 608  */
 609 static int ipc_mux_ul_bytes_credits_check(struct iosm_mux *ipc_mux,
 610                                           struct mux_session *session,
 611                                           struct sk_buff_head *ul_list,
 612                                           int max_nr_of_pkts)
 613 {
 614         int pkts_to_send = 0;
 615         struct sk_buff *skb;
 616         int credits = 0;
 617
 618         if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS) {
 619                 credits = session->ul_flow_credits;
 620                 if (credits <= 0) {
 621                         dev_dbg(ipc_mux->dev,
 622                                 "FC::if_id[%d] Insuff.Credits/Qlen:%d/%u",
 623                                 session->if_id, session->ul_flow_credits,
 624                                 session->ul_list.qlen); /* nr_of_bytes */
 625                         return 0;
 626                 }
 627         } else {
 628                 credits = IPC_MEM_MUX_UL_FLOWCTRL_HIGH_B -
 629                           ipc_mux->ul_data_pend_bytes;
 630                 if (credits <= 0) {
 631                         ipc_mux_stop_tx_for_all_sessions(ipc_mux);
 632
 633                         dev_dbg(ipc_mux->dev,
 634                                 "if_id[%d] encod. fail Bytes: %llu, thresh: %d",
 635                                 session->if_id, ipc_mux->ul_data_pend_bytes,
 636                                 IPC_MEM_MUX_UL_FLOWCTRL_HIGH_B);
 637                         return 0;
 638                 }
 639         }
 640
 641         /* Check if there are enough credits/bytes available to send the
 642          * requested max_nr_of_pkts. Otherwise restrict the nr_of_pkts
 643          * depending on available credits.
 644          */
 645         skb_queue_walk(ul_list, skb)
 646         {
 647                 if (!(credits >= skb->len && pkts_to_send < max_nr_of_pkts))
 648                         break;
 649                 credits -= skb->len;
 650                 pkts_to_send++;
 651         }
 652
 653         return pkts_to_send;
 654 }
 655
 656 /* Encode the UL IP packet according to Lite spec. */
 657 static int ipc_mux_ul_adgh_encode(struct iosm_mux *ipc_mux, int session_id,
 658                                   struct mux_session *session,
 659                                   struct sk_buff_head *ul_list,
 660                                   struct mux_adb *adb, int nr_of_pkts)
 661 {
 662         int offset = sizeof(struct mux_adgh);
 663         int adb_updated = -EINVAL;
 664         struct sk_buff *src_skb;
 665         int aligned_size = 0;
 666         int nr_of_skb = 0;
 667         u32 pad_len = 0;
 668
 669         /* Re-calculate the number of packets depending on number of bytes to be
 670          * processed/available credits.
 671          */
 672         nr_of_pkts = ipc_mux_ul_bytes_credits_check(ipc_mux, session, ul_list,
 673                                                     nr_of_pkts);
 674
 675         /* If calculated nr_of_pkts from available credits is <= 0
 676          * then nothing to do.
 677          */
 678         if (nr_of_pkts <= 0)
 679                 return 0;
 680
 681         /* Read configured UL head_pad_length for session.*/
 682         if (session->ul_head_pad_len > IPC_MEM_DL_ETH_OFFSET)
 683                 pad_len = session->ul_head_pad_len - IPC_MEM_DL_ETH_OFFSET;
 684
 685         /* Process all pending UL packets for this session
 686          * depending on the allocated datagram table size.
 687          */
 688         while (nr_of_pkts > 0) {
 689                 /* get destination skb allocated */
 690                 if (ipc_mux_ul_adb_allocate(ipc_mux, adb, &ipc_mux->size_needed,
 691                                             MUX_SIG_ADGH)) {
 692                         dev_err(ipc_mux->dev, "no reserved memory for ADGH");
 693                         return -ENOMEM;
 694                 }
 695
 696                 /* Peek at the head of the list. */
 697                 src_skb = skb_peek(ul_list);
 698                 if (!src_skb) {
 699                         dev_err(ipc_mux->dev,
 700                                 "skb peek return NULL with count : %d",
 701                                 nr_of_pkts);
 702                         break;
 703                 }
 704
 705                 /* Calculate the memory value. */
 706                 aligned_size = ALIGN((pad_len + src_skb->len), 4);
 707
 708                 ipc_mux->size_needed = sizeof(struct mux_adgh) + aligned_size;
 709
 710                 if (ipc_mux->size_needed > adb->size) {
 711                         dev_dbg(ipc_mux->dev, "size needed %d, adgh size %d",
 712                                 ipc_mux->size_needed, adb->size);
 713                         /* Return 1 if any IP packet is added to the transfer
 714                          * list.
 715                          */
 716                         return nr_of_skb ? 1 : 0;
 717                 }
 718
 719                 /* Add buffer (without head padding to next pending transfer) */
 720                 memcpy(adb->buf + offset + pad_len, src_skb->data,
 721                        src_skb->len);
 722
 723                 adb->adgh->signature = cpu_to_le32(MUX_SIG_ADGH);
 724                 adb->adgh->if_id = session_id;
 725                 adb->adgh->length =
 726                         cpu_to_le16(sizeof(struct mux_adgh) + pad_len +
 727                                     src_skb->len);
 728                 adb->adgh->service_class = src_skb->priority;
 729                 adb->adgh->next_count = --nr_of_pkts;
 730                 adb->dg_cnt_total++;
 731                 adb->payload_size += src_skb->len;
 732
 733                 if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS)
 734                         /* Decrement the credit value as we are processing the
 735                          * datagram from the UL list.
 736                          */
 737                         session->ul_flow_credits -= src_skb->len;
 738
 739                 /* Remove the processed elements and free it. */
 740                 src_skb = skb_dequeue(ul_list);
 741                 dev_kfree_skb(src_skb);
 742                 nr_of_skb++;
 743
 744                 ipc_mux_ul_adgh_finish(ipc_mux);
 745         }
 746
 747         if (nr_of_skb) {
 748                 /* Send QLT info to modem if pending bytes > high watermark
 749                  * in case of mux lite
 750                  */
 751                 if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS ||
 752                     ipc_mux->ul_data_pend_bytes >=
 753                             IPC_MEM_MUX_UL_FLOWCTRL_LOW_B)
 754                         adb_updated = ipc_mux_lite_send_qlt(ipc_mux);
 755                 else
 756                         adb_updated = 1;
 757
 758                 /* Updates the TDs with ul_list */
 759                 (void)ipc_imem_ul_write_td(ipc_mux->imem);
 760         }
 761
 762         return adb_updated;
 763 }
 764
 765 bool ipc_mux_ul_data_encode(struct iosm_mux *ipc_mux)
 766 {
 767         struct sk_buff_head *ul_list;
 768         struct mux_session *session;
 769         int updated = 0;
 770         int session_id;
 771         int dg_n;
 772         int i;
 773
 774         if (!ipc_mux || ipc_mux->state != MUX_S_ACTIVE ||
 775             ipc_mux->adb_prep_ongoing)
 776                 return false;
 777
 778         ipc_mux->adb_prep_ongoing = true;
 779
 780         for (i = 0; i < ipc_mux->nr_sessions; i++) {
 781                 session_id = ipc_mux->rr_next_session;
 782                 session = &ipc_mux->session[session_id];
 783
 784                 /* Go to next handle rr_next_session overflow */
 785                 ipc_mux->rr_next_session++;
 786                 if (ipc_mux->rr_next_session >= ipc_mux->nr_sessions)
 787                         ipc_mux->rr_next_session = 0;
 788
 789                 if (!session->wwan || session->flow_ctl_mask ||
 790                     session->net_tx_stop)
 791                         continue;
 792
 793                 ul_list = &session->ul_list;
 794
 795                 /* Is something pending in UL and flow ctrl off */
 796                 dg_n = skb_queue_len(ul_list);
 797                 if (dg_n > MUX_MAX_UL_DG_ENTRIES)
 798                         dg_n = MUX_MAX_UL_DG_ENTRIES;
 799
 800                 if (dg_n == 0)
 801                         /* Nothing to do for ipc_mux session
 802                          * -> try next session id.
 803                          */
 804                         continue;
 805
 806                 updated = ipc_mux_ul_adgh_encode(ipc_mux, session_id, session,
 807                                                  ul_list, &ipc_mux->ul_adb,
 808                                                  dg_n);
 809         }
 810
 811         ipc_mux->adb_prep_ongoing = false;
 812         return updated == 1;
 813 }
 814
 815 void ipc_mux_ul_encoded_process(struct iosm_mux *ipc_mux, struct sk_buff *skb)
 816 {
 817         struct mux_adgh *adgh;
 818         u16 adgh_len;
 819
 820         adgh = (struct mux_adgh *)skb->data;
 821         adgh_len = le16_to_cpu(adgh->length);
 822
 823         if (adgh->signature == cpu_to_le32(MUX_SIG_ADGH) &&
 824             ipc_mux->ul_flow == MUX_UL)
 825                 ipc_mux->ul_data_pend_bytes = ipc_mux->ul_data_pend_bytes -
 826                                               adgh_len;
 827
 828         if (ipc_mux->ul_flow == MUX_UL)
 829                 dev_dbg(ipc_mux->dev, "ul_data_pend_bytes: %lld",
 830                         ipc_mux->ul_data_pend_bytes);
 831
 832         /* Reset the skb settings. */
 833         skb->tail = 0;
 834         skb->len = 0;
 835
 836         /* Add the consumed ADB to the free list. */
 837         skb_queue_tail((&ipc_mux->ul_adb.free_list), skb);
 838 }
 839
 840 /* Start the NETIF uplink send transfer in MUX mode. */
 841 static int ipc_mux_tq_ul_trigger_encode(struct iosm_imem *ipc_imem, int arg,
 842                                         void *msg, size_t size)
 843 {
 844         struct iosm_mux *ipc_mux = ipc_imem->mux;
 845         bool ul_data_pend = false;
 846
 847         /* Add session UL data to a ADB and ADGH */
 848         ul_data_pend = ipc_mux_ul_data_encode(ipc_mux);
 849         if (ul_data_pend)
 850                 /* Delay the doorbell irq */
 851                 ipc_imem_td_update_timer_start(ipc_mux->imem);
 852
 853         /* reset the debounce flag */
 854         ipc_mux->ev_mux_net_transmit_pending = false;
 855
 856         return 0;
 857 }
 858
 859 int ipc_mux_ul_trigger_encode(struct iosm_mux *ipc_mux, int if_id,
 860                               struct sk_buff *skb)
 861 {
 862         struct mux_session *session = &ipc_mux->session[if_id];
 863         int ret = -EINVAL;
 864
 865         if (ipc_mux->channel &&
 866             ipc_mux->channel->state != IMEM_CHANNEL_ACTIVE) {
 867                 dev_err(ipc_mux->dev,
 868                         "channel state is not IMEM_CHANNEL_ACTIVE");
 869                 goto out;
 870         }
 871
 872         if (!session->wwan) {
 873                 dev_err(ipc_mux->dev, "session net ID is NULL");
 874                 ret = -EFAULT;
 875                 goto out;
 876         }
 877
 878         /* Session is under flow control.
 879          * Check if packet can be queued in session list, if not
 880          * suspend net tx
 881          */
 882         if (skb_queue_len(&session->ul_list) >=
 883             (session->net_tx_stop ?
 884                      IPC_MEM_MUX_UL_SESS_FCON_THRESHOLD :
 885                      (IPC_MEM_MUX_UL_SESS_FCON_THRESHOLD *
 886                       IPC_MEM_MUX_UL_SESS_FCOFF_THRESHOLD_FACTOR))) {
 887                 ipc_mux_netif_tx_flowctrl(session, session->if_id, true);
 888                 ret = -EBUSY;
 889                 goto out;
 890         }
 891
 892         /* Add skb to the uplink skb accumulator. */
 893         skb_queue_tail(&session->ul_list, skb);
 894
 895         /* Inform the IPC kthread to pass uplink IP packets to CP. */
 896         if (!ipc_mux->ev_mux_net_transmit_pending) {
 897                 ipc_mux->ev_mux_net_transmit_pending = true;
 898                 ret = ipc_task_queue_send_task(ipc_mux->imem,
 899                                                ipc_mux_tq_ul_trigger_encode, 0,
 900                                                NULL, 0, false);
 901                 if (ret)
 902                         goto out;
 903         }
 904         dev_dbg(ipc_mux->dev, "mux ul if[%d] qlen=%d/%u, len=%d/%d, prio=%d",
 905                 if_id, skb_queue_len(&session->ul_list), session->ul_list.qlen,
 906                 skb->len, skb->truesize, skb->priority);
 907         ret = 0;
 908 out:
 909         return ret;
 910 }