drivers/net/wwan/iosm/iosm_ipc_mux.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2020-21 Intel Corporation.
   4  */
   5
   6 #include "iosm_ipc_mux_codec.h"
   7
   8 /* At the begin of the runtime phase the IP MUX channel shall created. */
   9 static int ipc_mux_channel_create(struct iosm_mux *ipc_mux)
  10 {
  11         int channel_id;
  12
  13         channel_id = ipc_imem_channel_alloc(ipc_mux->imem, ipc_mux->instance_id,
  14                                             IPC_CTYPE_WWAN);
  15
  16         if (channel_id < 0) {
  17                 dev_err(ipc_mux->dev,
  18                         "allocation of the MUX channel id failed");
  19                 ipc_mux->state = MUX_S_ERROR;
  20                 ipc_mux->event = MUX_E_NOT_APPLICABLE;
  21                 goto no_channel;
  22         }
  23
  24         /* Establish the MUX channel in blocking mode. */
  25         ipc_mux->channel = ipc_imem_channel_open(ipc_mux->imem, channel_id,
  26                                                  IPC_HP_NET_CHANNEL_INIT);
  27
  28         if (!ipc_mux->channel) {
  29                 dev_err(ipc_mux->dev, "ipc_imem_channel_open failed");
  30                 ipc_mux->state = MUX_S_ERROR;
  31                 ipc_mux->event = MUX_E_NOT_APPLICABLE;
  32                 return -ENODEV; /* MUX channel is not available. */
  33         }
  34
  35         /* Define the MUX active state properties. */
  36         ipc_mux->state = MUX_S_ACTIVE;
  37         ipc_mux->event = MUX_E_NO_ORDERS;
  38
  39 no_channel:
  40         return channel_id;
  41 }
  42
  43 /* Reset the session/if id state. */
  44 static void ipc_mux_session_free(struct iosm_mux *ipc_mux, int if_id)
  45 {
  46         struct mux_session *if_entry;
  47
  48         if_entry = &ipc_mux->session[if_id];
  49         /* Reset the session state. */
  50         if_entry->wwan = NULL;
  51 }
  52
  53 /* Create and send the session open command. */
  54 static struct mux_cmd_open_session_resp *
  55 ipc_mux_session_open_send(struct iosm_mux *ipc_mux, int if_id)
  56 {
  57         struct mux_cmd_open_session_resp *open_session_resp;
  58         struct mux_acb *acb = &ipc_mux->acb;
  59         union mux_cmd_param param;
  60
  61         /* open_session commands to one ACB and start transmission. */
  62         param.open_session.flow_ctrl = 0;
  63         param.open_session.ipv4v6_hints = 0;
  64         param.open_session.reserved2 = 0;
  65         param.open_session.dl_head_pad_len = cpu_to_le32(IPC_MEM_DL_ETH_OFFSET);
  66
  67         /* Finish and transfer ACB. The user thread is suspended.
  68          * It is a blocking function call, until CP responds or timeout.
  69          */
  70         acb->wanted_response = MUX_CMD_OPEN_SESSION_RESP;
  71         if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_OPEN_SESSION, if_id, 0,
  72                                      &param, sizeof(param.open_session), true,
  73                                  false) ||
  74             acb->got_response != MUX_CMD_OPEN_SESSION_RESP) {
  75                 dev_err(ipc_mux->dev, "if_id %d: OPEN_SESSION send failed",
  76                         if_id);
  77                 return NULL;
  78         }
  79
  80         open_session_resp = &ipc_mux->acb.got_param.open_session_resp;
  81         if (open_session_resp->response != cpu_to_le32(MUX_CMD_RESP_SUCCESS)) {
  82                 dev_err(ipc_mux->dev,
  83                         "if_id %d,session open failed,response=%d", if_id,
  84                         open_session_resp->response);
  85                 return NULL;
  86         }
  87
  88         return open_session_resp;
  89 }
  90
  91 /* Open the first IP session. */
  92 static bool ipc_mux_session_open(struct iosm_mux *ipc_mux,
  93                                  struct mux_session_open *session_open)
  94 {
  95         struct mux_cmd_open_session_resp *open_session_resp;
  96         int if_id;
  97
  98         /* Search for a free session interface id. */
  99         if_id = le32_to_cpu(session_open->if_id);
 100         if (if_id < 0 || if_id >= ipc_mux->nr_sessions) {
 101                 dev_err(ipc_mux->dev, "invalid interface id=%d", if_id);
 102                 return false;
 103         }
 104
 105         /* Create and send the session open command.
 106          * It is a blocking function call, until CP responds or timeout.
 107          */
 108         open_session_resp = ipc_mux_session_open_send(ipc_mux, if_id);
 109         if (!open_session_resp) {
 110                 ipc_mux_session_free(ipc_mux, if_id);
 111                 session_open->if_id = cpu_to_le32(-1);
 112                 return false;
 113         }
 114
 115         /* Initialize the uplink skb accumulator. */
 116         skb_queue_head_init(&ipc_mux->session[if_id].ul_list);
 117
 118         ipc_mux->session[if_id].dl_head_pad_len = IPC_MEM_DL_ETH_OFFSET;
 119         ipc_mux->session[if_id].ul_head_pad_len =
 120                 le32_to_cpu(open_session_resp->ul_head_pad_len);
 121         ipc_mux->session[if_id].wwan = ipc_mux->wwan;
 122
 123         /* Reset the flow ctrl stats of the session */
 124         ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
 125         ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
 126         ipc_mux->session[if_id].ul_flow_credits = 0;
 127         ipc_mux->session[if_id].net_tx_stop = false;
 128         ipc_mux->session[if_id].flow_ctl_mask = 0;
 129
 130         /* Save and return the assigned if id. */
 131         session_open->if_id = cpu_to_le32(if_id);
 132
 133         return true;
 134 }
 135
 136 /* Free pending session UL packet. */
 137 static void ipc_mux_session_reset(struct iosm_mux *ipc_mux, int if_id)
 138 {
 139         /* Reset the session/if id state. */
 140         ipc_mux_session_free(ipc_mux, if_id);
 141
 142         /* Empty the uplink skb accumulator. */
 143         skb_queue_purge(&ipc_mux->session[if_id].ul_list);
 144 }
 145
 146 static void ipc_mux_session_close(struct iosm_mux *ipc_mux,
 147                                   struct mux_session_close *msg)
 148 {
 149         int if_id;
 150
 151         /* Copy the session interface id. */
 152         if_id = le32_to_cpu(msg->if_id);
 153
 154         if (if_id < 0 || if_id >= ipc_mux->nr_sessions) {
 155                 dev_err(ipc_mux->dev, "invalid session id %d", if_id);
 156                 return;
 157         }
 158
 159         /* Create and send the session close command.
 160          * It is a blocking function call, until CP responds or timeout.
 161          */
 162         if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_CLOSE_SESSION, if_id, 0,
 163                                      NULL, 0, true, false))
 164                 dev_err(ipc_mux->dev, "if_id %d: CLOSE_SESSION send failed",
 165                         if_id);
 166
 167         /* Reset the flow ctrl stats of the session */
 168         ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
 169         ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
 170         ipc_mux->session[if_id].flow_ctl_mask = 0;
 171
 172         ipc_mux_session_reset(ipc_mux, if_id);
 173 }
 174
 175 static void ipc_mux_channel_close(struct iosm_mux *ipc_mux,
 176                                   struct mux_channel_close *channel_close_p)
 177 {
 178         int i;
 179
 180         /* Free pending session UL packet. */
 181         for (i = 0; i < ipc_mux->nr_sessions; i++)
 182                 if (ipc_mux->session[i].wwan)
 183                         ipc_mux_session_reset(ipc_mux, i);
 184
 185         ipc_imem_channel_close(ipc_mux->imem, ipc_mux->channel_id);
 186
 187         /* Reset the MUX object. */
 188         ipc_mux->state = MUX_S_INACTIVE;
 189         ipc_mux->event = MUX_E_INACTIVE;
 190 }
 191
 192 /* CP has interrupted AP. If AP is in IP MUX mode, execute the pending ops. */
 193 static int ipc_mux_schedule(struct iosm_mux *ipc_mux, union mux_msg *msg)
 194 {
 195         enum mux_event order;
 196         bool success;
 197         int ret = -EIO;
 198
 199         if (!ipc_mux->initialized) {
 200                 ret = -EAGAIN;
 201                 goto out;
 202         }
 203
 204         order = msg->common.event;
 205
 206         switch (ipc_mux->state) {
 207         case MUX_S_INACTIVE:
 208                 if (order != MUX_E_MUX_SESSION_OPEN)
 209                         goto out; /* Wait for the request to open a session */
 210
 211                 if (ipc_mux->event == MUX_E_INACTIVE)
 212                         /* Establish the MUX channel and the new state. */
 213                         ipc_mux->channel_id = ipc_mux_channel_create(ipc_mux);
 214
 215                 if (ipc_mux->state != MUX_S_ACTIVE) {
 216                         ret = ipc_mux->channel_id; /* Missing the MUX channel */
 217                         goto out;
 218                 }
 219
 220                 /* Disable the TD update timer and open the first IP session. */
 221                 ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
 222                 ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
 223                 success = ipc_mux_session_open(ipc_mux, &msg->session_open);
 224
 225                 ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
 226                 if (success)
 227                         ret = ipc_mux->channel_id;
 228                 goto out;
 229
 230         case MUX_S_ACTIVE:
 231                 switch (order) {
 232                 case MUX_E_MUX_SESSION_OPEN:
 233                         /* Disable the TD update timer and open a session */
 234                         ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
 235                         ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
 236                         success = ipc_mux_session_open(ipc_mux,
 237                                                        &msg->session_open);
 238                         ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
 239                         if (success)
 240                                 ret = ipc_mux->channel_id;
 241                         goto out;
 242
 243                 case MUX_E_MUX_SESSION_CLOSE:
 244                         /* Release an IP session. */
 245                         ipc_mux->event = MUX_E_MUX_SESSION_CLOSE;
 246                         ipc_mux_session_close(ipc_mux, &msg->session_close);
 247                         ret = ipc_mux->channel_id;
 248                         goto out;
 249
 250                 case MUX_E_MUX_CHANNEL_CLOSE:
 251                         /* Close the MUX channel pipes. */
 252                         ipc_mux->event = MUX_E_MUX_CHANNEL_CLOSE;
 253                         ipc_mux_channel_close(ipc_mux, &msg->channel_close);
 254                         ret = ipc_mux->channel_id;
 255                         goto out;
 256
 257                 default:
 258                         /* Invalid order. */
 259                         goto out;
 260                 }
 261
 262         default:
 263                 dev_err(ipc_mux->dev,
 264                         "unexpected MUX transition: state=%d, event=%d",
 265                         ipc_mux->state, ipc_mux->event);
 266         }
 267 out:
 268         return ret;
 269 }
 270
 271 struct iosm_mux *ipc_mux_init(struct ipc_mux_config *mux_cfg,
 272                               struct iosm_imem *imem)
 273 {
 274         struct iosm_mux *ipc_mux = kzalloc(sizeof(*ipc_mux), GFP_KERNEL);
 275         int i, ul_tds, ul_td_size;
 276         struct sk_buff_head *free_list;
 277         struct sk_buff *skb;
 278
 279         if (!ipc_mux)
 280                 return NULL;
 281
 282         ipc_mux->protocol = mux_cfg->protocol;
 283         ipc_mux->ul_flow = mux_cfg->ul_flow;
 284         ipc_mux->nr_sessions = mux_cfg->nr_sessions;
 285         ipc_mux->instance_id = mux_cfg->instance_id;
 286         ipc_mux->wwan_q_offset = 0;
 287
 288         ipc_mux->pcie = imem->pcie;
 289         ipc_mux->imem = imem;
 290         ipc_mux->ipc_protocol = imem->ipc_protocol;
 291         ipc_mux->dev = imem->dev;
 292         ipc_mux->wwan = imem->wwan;
 293
 294         /* Get the reference to the UL ADB list. */
 295         free_list = &ipc_mux->ul_adb.free_list;
 296
 297         /* Initialize the list with free ADB. */
 298         skb_queue_head_init(free_list);
 299
 300         ul_td_size = IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE;
 301
 302         ul_tds = IPC_MEM_MAX_TDS_MUX_LITE_UL;
 303
 304         ipc_mux->ul_adb.dest_skb = NULL;
 305
 306         ipc_mux->initialized = true;
 307         ipc_mux->adb_prep_ongoing = false;
 308         ipc_mux->size_needed = 0;
 309         ipc_mux->ul_data_pend_bytes = 0;
 310         ipc_mux->state = MUX_S_INACTIVE;
 311         ipc_mux->ev_mux_net_transmit_pending = false;
 312         ipc_mux->tx_transaction_id = 0;
 313         ipc_mux->rr_next_session = 0;
 314         ipc_mux->event = MUX_E_INACTIVE;
 315         ipc_mux->channel_id = -1;
 316         ipc_mux->channel = NULL;
 317
 318         /* Allocate the list of UL ADB. */
 319         for (i = 0; i < ul_tds; i++) {
 320                 dma_addr_t mapping;
 321
 322                 skb = ipc_pcie_alloc_skb(ipc_mux->pcie, ul_td_size, GFP_ATOMIC,
 323                                          &mapping, DMA_TO_DEVICE, 0);
 324                 if (!skb) {
 325                         ipc_mux_deinit(ipc_mux);
 326                         return NULL;
 327                 }
 328                 /* Extend the UL ADB list. */
 329                 skb_queue_tail(free_list, skb);
 330         }
 331
 332         return ipc_mux;
 333 }
 334
 335 /* Informs the network stack to restart transmission for all opened session if
 336  * Flow Control is not ON for that session.
 337  */
 338 static void ipc_mux_restart_tx_for_all_sessions(struct iosm_mux *ipc_mux)
 339 {
 340         struct mux_session *session;
 341         int idx;
 342
 343         for (idx = 0; idx < ipc_mux->nr_sessions; idx++) {
 344                 session = &ipc_mux->session[idx];
 345
 346                 if (!session->wwan)
 347                         continue;
 348
 349                 /* If flow control of the session is OFF and if there was tx
 350                  * stop then restart. Inform the network interface to restart
 351                  * sending data.
 352                  */
 353                 if (session->flow_ctl_mask == 0) {
 354                         session->net_tx_stop = false;
 355                         ipc_mux_netif_tx_flowctrl(session, idx, false);
 356                 }
 357         }
 358 }
 359
 360 /* Informs the network stack to stop sending further pkt for all opened
 361  * sessions
 362  */
 363 static void ipc_mux_stop_netif_for_all_sessions(struct iosm_mux *ipc_mux)
 364 {
 365         struct mux_session *session;
 366         int idx;
 367
 368         for (idx = 0; idx < ipc_mux->nr_sessions; idx++) {
 369                 session = &ipc_mux->session[idx];
 370
 371                 if (!session->wwan)
 372                         continue;
 373
 374                 ipc_mux_netif_tx_flowctrl(session, session->if_id, true);
 375         }
 376 }
 377
 378 void ipc_mux_check_n_restart_tx(struct iosm_mux *ipc_mux)
 379 {
 380         if (ipc_mux->ul_flow == MUX_UL) {
 381                 int low_thresh = IPC_MEM_MUX_UL_FLOWCTRL_LOW_B;
 382
 383                 if (ipc_mux->ul_data_pend_bytes < low_thresh)
 384                         ipc_mux_restart_tx_for_all_sessions(ipc_mux);
 385         }
 386 }
 387
 388 int ipc_mux_get_max_sessions(struct iosm_mux *ipc_mux)
 389 {
 390         return ipc_mux ? ipc_mux->nr_sessions : -EFAULT;
 391 }
 392
 393 enum ipc_mux_protocol ipc_mux_get_active_protocol(struct iosm_mux *ipc_mux)
 394 {
 395         return ipc_mux ? ipc_mux->protocol : MUX_UNKNOWN;
 396 }
 397
 398 int ipc_mux_open_session(struct iosm_mux *ipc_mux, int session_nr)
 399 {
 400         struct mux_session_open *session_open;
 401         union mux_msg mux_msg;
 402
 403         session_open = &mux_msg.session_open;
 404         session_open->event = MUX_E_MUX_SESSION_OPEN;
 405
 406         session_open->if_id = cpu_to_le32(session_nr);
 407         ipc_mux->session[session_nr].flags |= IPC_MEM_WWAN_MUX;
 408         return ipc_mux_schedule(ipc_mux, &mux_msg);
 409 }
 410
 411 int ipc_mux_close_session(struct iosm_mux *ipc_mux, int session_nr)
 412 {
 413         struct mux_session_close *session_close;
 414         union mux_msg mux_msg;
 415         int ret_val;
 416
 417         session_close = &mux_msg.session_close;
 418         session_close->event = MUX_E_MUX_SESSION_CLOSE;
 419
 420         session_close->if_id = cpu_to_le32(session_nr);
 421         ret_val = ipc_mux_schedule(ipc_mux, &mux_msg);
 422         ipc_mux->session[session_nr].flags &= ~IPC_MEM_WWAN_MUX;
 423
 424         return ret_val;
 425 }
 426
 427 void ipc_mux_deinit(struct iosm_mux *ipc_mux)
 428 {
 429         struct mux_channel_close *channel_close;
 430         struct sk_buff_head *free_list;
 431         union mux_msg mux_msg;
 432         struct sk_buff *skb;
 433
 434         if (!ipc_mux->initialized)
 435                 return;
 436         ipc_mux_stop_netif_for_all_sessions(ipc_mux);
 437
 438         channel_close = &mux_msg.channel_close;
 439         channel_close->event = MUX_E_MUX_CHANNEL_CLOSE;
 440         ipc_mux_schedule(ipc_mux, &mux_msg);
 441
 442         /* Empty the ADB free list. */
 443         free_list = &ipc_mux->ul_adb.free_list;
 444
 445         /* Remove from the head of the downlink queue. */
 446         while ((skb = skb_dequeue(free_list)))
 447                 ipc_pcie_kfree_skb(ipc_mux->pcie, skb);
 448
 449         if (ipc_mux->channel) {
 450                 ipc_mux->channel->ul_pipe.is_open = false;
 451                 ipc_mux->channel->dl_pipe.is_open = false;
 452         }
 453
 454         kfree(ipc_mux);
 455 }