root/drivers/hid/intel-ish-hid/ishtp/hbm.c

DEFINITIONS

1. ishtp_hbm_fw_cl_allocate
2. ishtp_hbm_cl_hdr
3. ishtp_hbm_cl_addr_equal
4. ishtp_hbm_start_wait
5. ishtp_hbm_start_req
6. ishtp_hbm_enum_clients_req
7. ishtp_hbm_prop_req
8. ishtp_hbm_stop_req
9. ishtp_hbm_cl_flow_control_req
10. ishtp_hbm_cl_disconnect_req
11. ishtp_hbm_cl_disconnect_res
12. ishtp_hbm_cl_connect_req
13. ishtp_hbm_cl_connect_res
14. ishtp_hbm_fw_disconnect_req
15. ishtp_hbm_dma_xfer_ack
16. ishtp_hbm_dma_xfer
17. ishtp_hbm_dispatch
18. bh_hbm_work_fn
19. recv_hbm
20. recv_fixed_cl_msg
21. fix_cl_hdr
22. ishtp_send_suspend
23. ishtp_send_resume
24. ishtp_query_subscribers

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ISHTP bus layer messages handling
   4  *
   5  * Copyright (c) 2003-2016, Intel Corporation.
   6  */
   7 
   8 #include <linux/export.h>
   9 #include <linux/slab.h>
  10 #include <linux/sched.h>
  11 #include <linux/wait.h>
  12 #include <linux/spinlock.h>
  13 #include "ishtp-dev.h"
  14 #include "hbm.h"
  15 #include "client.h"
  16 
  17 /**
  18  * ishtp_hbm_fw_cl_allocate() - Allocate FW clients
  19  * @dev: ISHTP device instance
  20  *
  21  * Allocates storage for fw clients
  22  */
  23 static void ishtp_hbm_fw_cl_allocate(struct ishtp_device *dev)
  24 {
  25         struct ishtp_fw_client *clients;
  26         int b;
  27 
  28         /* count how many ISH clients we have */
  29         for_each_set_bit(b, dev->fw_clients_map, ISHTP_CLIENTS_MAX)
  30                 dev->fw_clients_num++;
  31 
  32         if (dev->fw_clients_num <= 0)
  33                 return;
  34 
  35         /* allocate storage for fw clients representation */
  36         clients = kcalloc(dev->fw_clients_num, sizeof(struct ishtp_fw_client),
  37                           GFP_KERNEL);
  38         if (!clients) {
  39                 dev->dev_state = ISHTP_DEV_RESETTING;
  40                 ish_hw_reset(dev);
  41                 return;
  42         }
  43         dev->fw_clients = clients;
  44 }
  45 
  46 /**
  47  * ishtp_hbm_cl_hdr() - construct client hbm header
  48  * @cl: client
  49  * @hbm_cmd: host bus message command
  50  * @buf: buffer for cl header
  51  * @len: buffer length
  52  *
  53  * Initialize HBM buffer
  54  */
  55 static inline void ishtp_hbm_cl_hdr(struct ishtp_cl *cl, uint8_t hbm_cmd,
  56         void *buf, size_t len)
  57 {
  58         struct ishtp_hbm_cl_cmd *cmd = buf;
  59 
  60         memset(cmd, 0, len);
  61 
  62         cmd->hbm_cmd = hbm_cmd;
  63         cmd->host_addr = cl->host_client_id;
  64         cmd->fw_addr = cl->fw_client_id;
  65 }
  66 
  67 /**
  68  * ishtp_hbm_cl_addr_equal() - Compare client address
  69  * @cl: client
  70  * @buf: Client command buffer
  71  *
  72  * Compare client address with the address in command buffer
  73  *
  74  * Return: True if they have the same address
  75  */
  76 static inline bool ishtp_hbm_cl_addr_equal(struct ishtp_cl *cl, void *buf)
  77 {
  78         struct ishtp_hbm_cl_cmd *cmd = buf;
  79 
  80         return cl->host_client_id == cmd->host_addr &&
  81                 cl->fw_client_id == cmd->fw_addr;
  82 }
  83 
  84 /**
  85  * ishtp_hbm_start_wait() - Wait for HBM start message
  86  * @dev: ISHTP device instance
  87  *
  88  * Wait for HBM start message from firmware
  89  *
  90  * Return: 0 if HBM start is/was received else timeout error
  91  */
  92 int ishtp_hbm_start_wait(struct ishtp_device *dev)
  93 {
  94         int ret;
  95 
  96         if (dev->hbm_state > ISHTP_HBM_START)
  97                 return 0;
  98 
  99         dev_dbg(dev->devc, "Going to wait for ishtp start. hbm_state=%08X\n",
 100                 dev->hbm_state);
 101         ret = wait_event_interruptible_timeout(dev->wait_hbm_recvd_msg,
 102                                         dev->hbm_state >= ISHTP_HBM_STARTED,
 103                                         (ISHTP_INTEROP_TIMEOUT * HZ));
 104 
 105         dev_dbg(dev->devc,
 106                 "Woke up from waiting for ishtp start. hbm_state=%08X\n",
 107                 dev->hbm_state);
 108 
 109         if (ret <= 0 && (dev->hbm_state <= ISHTP_HBM_START)) {
 110                 dev->hbm_state = ISHTP_HBM_IDLE;
 111                 dev_err(dev->devc,
 112                 "waiting for ishtp start failed. ret=%d hbm_state=%08X\n",
 113                         ret, dev->hbm_state);
 114                 return -ETIMEDOUT;
 115         }
 116         return 0;
 117 }
 118 
 119 /**
 120  * ishtp_hbm_start_req() - Send HBM start message
 121  * @dev: ISHTP device instance
 122  *
 123  * Send HBM start message to firmware
 124  *
 125  * Return: 0 if success else error code
 126  */
 127 int ishtp_hbm_start_req(struct ishtp_device *dev)
 128 {
 129         struct ishtp_msg_hdr hdr;
 130         struct hbm_host_version_request start_req = { 0 };
 131 
 132         ishtp_hbm_hdr(&hdr, sizeof(start_req));
 133 
 134         /* host start message */
 135         start_req.hbm_cmd = HOST_START_REQ_CMD;
 136         start_req.host_version.major_version = HBM_MAJOR_VERSION;
 137         start_req.host_version.minor_version = HBM_MINOR_VERSION;
 138 
 139         /*
 140          * (!) Response to HBM start may be so quick that this thread would get
 141          * preempted BEFORE managing to set hbm_state = ISHTP_HBM_START.
 142          * So set it at first, change back to ISHTP_HBM_IDLE upon failure
 143          */
 144         dev->hbm_state = ISHTP_HBM_START;
 145         if (ishtp_write_message(dev, &hdr, &start_req)) {
 146                 dev_err(dev->devc, "version message send failed\n");
 147                 dev->dev_state = ISHTP_DEV_RESETTING;
 148                 dev->hbm_state = ISHTP_HBM_IDLE;
 149                 ish_hw_reset(dev);
 150                 return -ENODEV;
 151         }
 152 
 153         return 0;
 154 }
 155 
 156 /**
 157  * ishtp_hbm_enum_clients_req() - Send client enum req
 158  * @dev: ISHTP device instance
 159  *
 160  * Send enumeration client request message
 161  *
 162  * Return: 0 if success else error code
 163  */
 164 void ishtp_hbm_enum_clients_req(struct ishtp_device *dev)
 165 {
 166         struct ishtp_msg_hdr hdr;
 167         struct hbm_host_enum_request enum_req = { 0 };
 168 
 169         /* enumerate clients */
 170         ishtp_hbm_hdr(&hdr, sizeof(enum_req));
 171         enum_req.hbm_cmd = HOST_ENUM_REQ_CMD;
 172 
 173         if (ishtp_write_message(dev, &hdr, &enum_req)) {
 174                 dev->dev_state = ISHTP_DEV_RESETTING;
 175                 dev_err(dev->devc, "enumeration request send failed\n");
 176                 ish_hw_reset(dev);
 177         }
 178         dev->hbm_state = ISHTP_HBM_ENUM_CLIENTS;
 179 }
 180 
 181 /**
 182  * ishtp_hbm_prop_req() - Request property
 183  * @dev: ISHTP device instance
 184  *
 185  * Request property for a single client
 186  *
 187  * Return: 0 if success else error code
 188  */
 189 static int ishtp_hbm_prop_req(struct ishtp_device *dev)
 190 {
 191         struct ishtp_msg_hdr hdr;
 192         struct hbm_props_request prop_req = { 0 };
 193         unsigned long next_client_index;
 194         uint8_t client_num;
 195 
 196         client_num = dev->fw_client_presentation_num;
 197 
 198         next_client_index = find_next_bit(dev->fw_clients_map,
 199                 ISHTP_CLIENTS_MAX, dev->fw_client_index);
 200 
 201         /* We got all client properties */
 202         if (next_client_index == ISHTP_CLIENTS_MAX) {
 203                 dev->hbm_state = ISHTP_HBM_WORKING;
 204                 dev->dev_state = ISHTP_DEV_ENABLED;
 205 
 206                 for (dev->fw_client_presentation_num = 1;
 207                         dev->fw_client_presentation_num < client_num + 1;
 208                                 ++dev->fw_client_presentation_num)
 209                         /* Add new client device */
 210                         ishtp_bus_new_client(dev);
 211                 return 0;
 212         }
 213 
 214         dev->fw_clients[client_num].client_id = next_client_index;
 215 
 216         ishtp_hbm_hdr(&hdr, sizeof(prop_req));
 217 
 218         prop_req.hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
 219         prop_req.address = next_client_index;
 220 
 221         if (ishtp_write_message(dev, &hdr, &prop_req)) {
 222                 dev->dev_state = ISHTP_DEV_RESETTING;
 223                 dev_err(dev->devc, "properties request send failed\n");
 224                 ish_hw_reset(dev);
 225                 return -EIO;
 226         }
 227 
 228         dev->fw_client_index = next_client_index;
 229 
 230         return 0;
 231 }
 232 
 233 /**
 234  * ishtp_hbm_stop_req() - Send HBM stop
 235  * @dev: ISHTP device instance
 236  *
 237  * Send stop request message
 238  */
 239 static void ishtp_hbm_stop_req(struct ishtp_device *dev)
 240 {
 241         struct ishtp_msg_hdr hdr;
 242         struct hbm_host_stop_request stop_req = { 0 } ;
 243 
 244         ishtp_hbm_hdr(&hdr, sizeof(stop_req));
 245 
 246         stop_req.hbm_cmd = HOST_STOP_REQ_CMD;
 247         stop_req.reason = DRIVER_STOP_REQUEST;
 248 
 249         ishtp_write_message(dev, &hdr, &stop_req);
 250 }
 251 
 252 /**
 253  * ishtp_hbm_cl_flow_control_req() - Send flow control request
 254  * @dev: ISHTP device instance
 255  * @cl: ISHTP client instance
 256  *
 257  * Send flow control request
 258  *
 259  * Return: 0 if success else error code
 260  */
 261 int ishtp_hbm_cl_flow_control_req(struct ishtp_device *dev,
 262                                   struct ishtp_cl *cl)
 263 {
 264         struct ishtp_msg_hdr hdr;
 265         struct hbm_flow_control flow_ctrl;
 266         const size_t len = sizeof(flow_ctrl);
 267         int     rv;
 268         unsigned long   flags;
 269 
 270         spin_lock_irqsave(&cl->fc_spinlock, flags);
 271 
 272         ishtp_hbm_hdr(&hdr, len);
 273         ishtp_hbm_cl_hdr(cl, ISHTP_FLOW_CONTROL_CMD, &flow_ctrl, len);
 274 
 275         /*
 276          * Sync possible race when RB recycle and packet receive paths
 277          * both try to send an out FC
 278          */
 279         if (cl->out_flow_ctrl_creds) {
 280                 spin_unlock_irqrestore(&cl->fc_spinlock, flags);
 281                 return  0;
 282         }
 283 
 284         cl->recv_msg_num_frags = 0;
 285 
 286         rv = ishtp_write_message(dev, &hdr, &flow_ctrl);
 287         if (!rv) {
 288                 ++cl->out_flow_ctrl_creds;
 289                 ++cl->out_flow_ctrl_cnt;
 290                 cl->ts_out_fc = ktime_get();
 291                 if (cl->ts_rx) {
 292                         ktime_t ts_diff = ktime_sub(cl->ts_out_fc, cl->ts_rx);
 293                         if (ktime_after(ts_diff, cl->ts_max_fc_delay))
 294                                 cl->ts_max_fc_delay = ts_diff;
 295                 }
 296         } else {
 297                 ++cl->err_send_fc;
 298         }
 299 
 300         spin_unlock_irqrestore(&cl->fc_spinlock, flags);
 301         return  rv;
 302 }
 303 
 304 /**
 305  * ishtp_hbm_cl_disconnect_req() - Send disconnect request
 306  * @dev: ISHTP device instance
 307  * @cl: ISHTP client instance
 308  *
 309  * Send disconnect message to fw
 310  *
 311  * Return: 0 if success else error code
 312  */
 313 int ishtp_hbm_cl_disconnect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
 314 {
 315         struct ishtp_msg_hdr hdr;
 316         struct hbm_client_connect_request disconn_req;
 317         const size_t len = sizeof(disconn_req);
 318 
 319         ishtp_hbm_hdr(&hdr, len);
 320         ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_REQ_CMD, &disconn_req, len);
 321 
 322         return ishtp_write_message(dev, &hdr, &disconn_req);
 323 }
 324 
 325 /**
 326  * ishtp_hbm_cl_disconnect_res() - Get disconnect response
 327  * @dev: ISHTP device instance
 328  * @rs: Response message
 329  *
 330  * Received disconnect response from fw
 331  */
 332 static void ishtp_hbm_cl_disconnect_res(struct ishtp_device *dev,
 333         struct hbm_client_connect_response *rs)
 334 {
 335         struct ishtp_cl *cl = NULL;
 336         unsigned long   flags;
 337 
 338         spin_lock_irqsave(&dev->cl_list_lock, flags);
 339         list_for_each_entry(cl, &dev->cl_list, link) {
 340                 if (!rs->status && ishtp_hbm_cl_addr_equal(cl, rs)) {
 341                         cl->state = ISHTP_CL_DISCONNECTED;
 342                         wake_up_interruptible(&cl->wait_ctrl_res);
 343                         break;
 344                 }
 345         }
 346         spin_unlock_irqrestore(&dev->cl_list_lock, flags);
 347 }
 348 
 349 /**
 350  * ishtp_hbm_cl_connect_req() - Send connect request
 351  * @dev: ISHTP device instance
 352  * @cl: client device instance
 353  *
 354  * Send connection request to specific fw client
 355  *
 356  * Return: 0 if success else error code
 357  */
 358 int ishtp_hbm_cl_connect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
 359 {
 360         struct ishtp_msg_hdr hdr;
 361         struct hbm_client_connect_request conn_req;
 362         const size_t len = sizeof(conn_req);
 363 
 364         ishtp_hbm_hdr(&hdr, len);
 365         ishtp_hbm_cl_hdr(cl, CLIENT_CONNECT_REQ_CMD, &conn_req, len);
 366 
 367         return ishtp_write_message(dev, &hdr, &conn_req);
 368 }
 369 
 370 /**
 371  * ishtp_hbm_cl_connect_res() - Get connect response
 372  * @dev: ISHTP device instance
 373  * @rs: Response message
 374  *
 375  * Received connect response from fw
 376  */
 377 static void ishtp_hbm_cl_connect_res(struct ishtp_device *dev,
 378         struct hbm_client_connect_response *rs)
 379 {
 380         struct ishtp_cl *cl = NULL;
 381         unsigned long   flags;
 382 
 383         spin_lock_irqsave(&dev->cl_list_lock, flags);
 384         list_for_each_entry(cl, &dev->cl_list, link) {
 385                 if (ishtp_hbm_cl_addr_equal(cl, rs)) {
 386                         if (!rs->status) {
 387                                 cl->state = ISHTP_CL_CONNECTED;
 388                                 cl->status = 0;
 389                         } else {
 390                                 cl->state = ISHTP_CL_DISCONNECTED;
 391                                 cl->status = -ENODEV;
 392                         }
 393                         wake_up_interruptible(&cl->wait_ctrl_res);
 394                         break;
 395                 }
 396         }
 397         spin_unlock_irqrestore(&dev->cl_list_lock, flags);
 398 }
 399 
 400 /**
 401  * ishtp_client_disconnect_request() - Receive disconnect request
 402  * @dev: ISHTP device instance
 403  * @disconnect_req: disconnect request structure
 404  *
 405  * Disconnect request bus message from the fw. Send diconnect response.
 406  */
 407 static void ishtp_hbm_fw_disconnect_req(struct ishtp_device *dev,
 408         struct hbm_client_connect_request *disconnect_req)
 409 {
 410         struct ishtp_cl *cl;
 411         const size_t len = sizeof(struct hbm_client_connect_response);
 412         unsigned long   flags;
 413         struct ishtp_msg_hdr hdr;
 414         unsigned char data[4];  /* All HBM messages are 4 bytes */
 415 
 416         spin_lock_irqsave(&dev->cl_list_lock, flags);
 417         list_for_each_entry(cl, &dev->cl_list, link) {
 418                 if (ishtp_hbm_cl_addr_equal(cl, disconnect_req)) {
 419                         cl->state = ISHTP_CL_DISCONNECTED;
 420 
 421                         /* send disconnect response */
 422                         ishtp_hbm_hdr(&hdr, len);
 423                         ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_RES_CMD, data,
 424                                 len);
 425                         ishtp_write_message(dev, &hdr, data);
 426                         break;
 427                 }
 428         }
 429         spin_unlock_irqrestore(&dev->cl_list_lock, flags);
 430 }
 431 
 432 /**
 433  * ishtp_hbm_dma_xfer_ack(() - Receive transfer ACK
 434  * @dev: ISHTP device instance
 435  * @dma_xfer: HBM transfer message
 436  *
 437  * Receive ack for ISHTP-over-DMA client message
 438  */
 439 static void ishtp_hbm_dma_xfer_ack(struct ishtp_device *dev,
 440                                    struct dma_xfer_hbm *dma_xfer)
 441 {
 442         void    *msg;
 443         uint64_t        offs;
 444         struct ishtp_msg_hdr    *ishtp_hdr =
 445                 (struct ishtp_msg_hdr *)&dev->ishtp_msg_hdr;
 446         unsigned int    msg_offs;
 447         struct ishtp_cl *cl;
 448 
 449         for (msg_offs = 0; msg_offs < ishtp_hdr->length;
 450                 msg_offs += sizeof(struct dma_xfer_hbm)) {
 451                 offs = dma_xfer->msg_addr - dev->ishtp_host_dma_tx_buf_phys;
 452                 if (offs > dev->ishtp_host_dma_tx_buf_size) {
 453                         dev_err(dev->devc, "Bad DMA Tx ack message address\n");
 454                         return;
 455                 }
 456                 if (dma_xfer->msg_length >
 457                                 dev->ishtp_host_dma_tx_buf_size - offs) {
 458                         dev_err(dev->devc, "Bad DMA Tx ack message size\n");
 459                         return;
 460                 }
 461 
 462                 /* logical address of the acked mem */
 463                 msg = (unsigned char *)dev->ishtp_host_dma_tx_buf + offs;
 464                 ishtp_cl_release_dma_acked_mem(dev, msg, dma_xfer->msg_length);
 465 
 466                 list_for_each_entry(cl, &dev->cl_list, link) {
 467                         if (cl->fw_client_id == dma_xfer->fw_client_id &&
 468                             cl->host_client_id == dma_xfer->host_client_id)
 469                                 /*
 470                                  * in case that a single ack may be sent
 471                                  * over several dma transfers, and the last msg
 472                                  * addr was inside the acked memory, but not in
 473                                  * its start
 474                                  */
 475                                 if (cl->last_dma_addr >=
 476                                                         (unsigned char *)msg &&
 477                                                 cl->last_dma_addr <
 478                                                 (unsigned char *)msg +
 479                                                 dma_xfer->msg_length) {
 480                                         cl->last_dma_acked = 1;
 481 
 482                                         if (!list_empty(&cl->tx_list.list) &&
 483                                                 cl->ishtp_flow_ctrl_creds) {
 484                                                 /*
 485                                                  * start sending the first msg
 486                                                  */
 487                                                 ishtp_cl_send_msg(dev, cl);
 488                                         }
 489                                 }
 490                 }
 491                 ++dma_xfer;
 492         }
 493 }
 494 
 495 /**
 496  * ishtp_hbm_dma_xfer() - Receive DMA transfer message
 497  * @dev: ISHTP device instance
 498  * @dma_xfer: HBM transfer message
 499  *
 500  * Receive ISHTP-over-DMA client message
 501  */
 502 static void ishtp_hbm_dma_xfer(struct ishtp_device *dev,
 503                                struct dma_xfer_hbm *dma_xfer)
 504 {
 505         void    *msg;
 506         uint64_t        offs;
 507         struct ishtp_msg_hdr    hdr;
 508         struct ishtp_msg_hdr    *ishtp_hdr =
 509                 (struct ishtp_msg_hdr *) &dev->ishtp_msg_hdr;
 510         struct dma_xfer_hbm     *prm = dma_xfer;
 511         unsigned int    msg_offs;
 512 
 513         for (msg_offs = 0; msg_offs < ishtp_hdr->length;
 514                 msg_offs += sizeof(struct dma_xfer_hbm)) {
 515 
 516                 offs = dma_xfer->msg_addr - dev->ishtp_host_dma_rx_buf_phys;
 517                 if (offs > dev->ishtp_host_dma_rx_buf_size) {
 518                         dev_err(dev->devc, "Bad DMA Rx message address\n");
 519                         return;
 520                 }
 521                 if (dma_xfer->msg_length >
 522                                 dev->ishtp_host_dma_rx_buf_size - offs) {
 523                         dev_err(dev->devc, "Bad DMA Rx message size\n");
 524                         return;
 525                 }
 526                 msg = dev->ishtp_host_dma_rx_buf + offs;
 527                 recv_ishtp_cl_msg_dma(dev, msg, dma_xfer);
 528                 dma_xfer->hbm = DMA_XFER_ACK;   /* Prepare for response */
 529                 ++dma_xfer;
 530         }
 531 
 532         /* Send DMA_XFER_ACK [...] */
 533         ishtp_hbm_hdr(&hdr, ishtp_hdr->length);
 534         ishtp_write_message(dev, &hdr, (unsigned char *)prm);
 535 }
 536 
 537 /**
 538  * ishtp_hbm_dispatch() - HBM dispatch function
 539  * @dev: ISHTP device instance
 540  * @hdr: bus message
 541  *
 542  * Bottom half read routine after ISR to handle the read bus message cmd
 543  * processing
 544  */
 545 void ishtp_hbm_dispatch(struct ishtp_device *dev,
 546                         struct ishtp_bus_message *hdr)
 547 {
 548         struct ishtp_bus_message *ishtp_msg;
 549         struct ishtp_fw_client *fw_client;
 550         struct hbm_host_version_response *version_res;
 551         struct hbm_client_connect_response *connect_res;
 552         struct hbm_client_connect_response *disconnect_res;
 553         struct hbm_client_connect_request *disconnect_req;
 554         struct hbm_props_response *props_res;
 555         struct hbm_host_enum_response *enum_res;
 556         struct ishtp_msg_hdr ishtp_hdr;
 557         struct dma_alloc_notify dma_alloc_notify;
 558         struct dma_xfer_hbm     *dma_xfer;
 559 
 560         ishtp_msg = hdr;
 561 
 562         switch (ishtp_msg->hbm_cmd) {
 563         case HOST_START_RES_CMD:
 564                 version_res = (struct hbm_host_version_response *)ishtp_msg;
 565                 if (!version_res->host_version_supported) {
 566                         dev->version = version_res->fw_max_version;
 567 
 568                         dev->hbm_state = ISHTP_HBM_STOPPED;
 569                         ishtp_hbm_stop_req(dev);
 570                         return;
 571                 }
 572 
 573                 dev->version.major_version = HBM_MAJOR_VERSION;
 574                 dev->version.minor_version = HBM_MINOR_VERSION;
 575                 if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
 576                                 dev->hbm_state == ISHTP_HBM_START) {
 577                         dev->hbm_state = ISHTP_HBM_STARTED;
 578                         ishtp_hbm_enum_clients_req(dev);
 579                 } else {
 580                         dev_err(dev->devc,
 581                                 "reset: wrong host start response\n");
 582                         /* BUG: why do we arrive here? */
 583                         ish_hw_reset(dev);
 584                         return;
 585                 }
 586 
 587                 wake_up_interruptible(&dev->wait_hbm_recvd_msg);
 588                 break;
 589 
 590         case CLIENT_CONNECT_RES_CMD:
 591                 connect_res = (struct hbm_client_connect_response *)ishtp_msg;
 592                 ishtp_hbm_cl_connect_res(dev, connect_res);
 593                 break;
 594 
 595         case CLIENT_DISCONNECT_RES_CMD:
 596                 disconnect_res =
 597                         (struct hbm_client_connect_response *)ishtp_msg;
 598                 ishtp_hbm_cl_disconnect_res(dev, disconnect_res);
 599                 break;
 600 
 601         case HOST_CLIENT_PROPERTIES_RES_CMD:
 602                 props_res = (struct hbm_props_response *)ishtp_msg;
 603                 fw_client = &dev->fw_clients[dev->fw_client_presentation_num];
 604 
 605                 if (props_res->status || !dev->fw_clients) {
 606                         dev_err(dev->devc,
 607                         "reset: properties response hbm wrong status\n");
 608                         ish_hw_reset(dev);
 609                         return;
 610                 }
 611 
 612                 if (fw_client->client_id != props_res->address) {
 613                         dev_err(dev->devc,
 614                                 "reset: host properties response address mismatch [%02X %02X]\n",
 615                                 fw_client->client_id, props_res->address);
 616                         ish_hw_reset(dev);
 617                         return;
 618                 }
 619 
 620                 if (dev->dev_state != ISHTP_DEV_INIT_CLIENTS ||
 621                         dev->hbm_state != ISHTP_HBM_CLIENT_PROPERTIES) {
 622                         dev_err(dev->devc,
 623                                 "reset: unexpected properties response\n");
 624                         ish_hw_reset(dev);
 625                         return;
 626                 }
 627 
 628                 fw_client->props = props_res->client_properties;
 629                 dev->fw_client_index++;
 630                 dev->fw_client_presentation_num++;
 631 
 632                 /* request property for the next client */
 633                 ishtp_hbm_prop_req(dev);
 634 
 635                 if (dev->dev_state != ISHTP_DEV_ENABLED)
 636                         break;
 637 
 638                 if (!ishtp_use_dma_transfer())
 639                         break;
 640 
 641                 dev_dbg(dev->devc, "Requesting to use DMA\n");
 642                 ishtp_cl_alloc_dma_buf(dev);
 643                 if (dev->ishtp_host_dma_rx_buf) {
 644                         const size_t len = sizeof(dma_alloc_notify);
 645 
 646                         memset(&dma_alloc_notify, 0, sizeof(dma_alloc_notify));
 647                         dma_alloc_notify.hbm = DMA_BUFFER_ALLOC_NOTIFY;
 648                         dma_alloc_notify.buf_size =
 649                                         dev->ishtp_host_dma_rx_buf_size;
 650                         dma_alloc_notify.buf_address =
 651                                         dev->ishtp_host_dma_rx_buf_phys;
 652                         ishtp_hbm_hdr(&ishtp_hdr, len);
 653                         ishtp_write_message(dev, &ishtp_hdr,
 654                                 (unsigned char *)&dma_alloc_notify);
 655                 }
 656 
 657                 break;
 658 
 659         case HOST_ENUM_RES_CMD:
 660                 enum_res = (struct hbm_host_enum_response *) ishtp_msg;
 661                 memcpy(dev->fw_clients_map, enum_res->valid_addresses, 32);
 662                 if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
 663                         dev->hbm_state == ISHTP_HBM_ENUM_CLIENTS) {
 664                         dev->fw_client_presentation_num = 0;
 665                         dev->fw_client_index = 0;
 666 
 667                         ishtp_hbm_fw_cl_allocate(dev);
 668                         dev->hbm_state = ISHTP_HBM_CLIENT_PROPERTIES;
 669 
 670                         /* first property request */
 671                         ishtp_hbm_prop_req(dev);
 672                 } else {
 673                         dev_err(dev->devc,
 674                               "reset: unexpected enumeration response hbm\n");
 675                         ish_hw_reset(dev);
 676                         return;
 677                 }
 678                 break;
 679 
 680         case HOST_STOP_RES_CMD:
 681                 if (dev->hbm_state != ISHTP_HBM_STOPPED)
 682                         dev_err(dev->devc, "unexpected stop response\n");
 683 
 684                 dev->dev_state = ISHTP_DEV_DISABLED;
 685                 dev_info(dev->devc, "reset: FW stop response\n");
 686                 ish_hw_reset(dev);
 687                 break;
 688 
 689         case CLIENT_DISCONNECT_REQ_CMD:
 690                 /* search for client */
 691                 disconnect_req =
 692                         (struct hbm_client_connect_request *)ishtp_msg;
 693                 ishtp_hbm_fw_disconnect_req(dev, disconnect_req);
 694                 break;
 695 
 696         case FW_STOP_REQ_CMD:
 697                 dev->hbm_state = ISHTP_HBM_STOPPED;
 698                 break;
 699 
 700         case DMA_BUFFER_ALLOC_RESPONSE:
 701                 dev->ishtp_host_dma_enabled = 1;
 702                 break;
 703 
 704         case DMA_XFER:
 705                 dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
 706                 if (!dev->ishtp_host_dma_enabled) {
 707                         dev_err(dev->devc,
 708                                 "DMA XFER requested but DMA is not enabled\n");
 709                         break;
 710                 }
 711                 ishtp_hbm_dma_xfer(dev, dma_xfer);
 712                 break;
 713 
 714         case DMA_XFER_ACK:
 715                 dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
 716                 if (!dev->ishtp_host_dma_enabled ||
 717                     !dev->ishtp_host_dma_tx_buf) {
 718                         dev_err(dev->devc,
 719                                 "DMA XFER acked but DMA Tx is not enabled\n");
 720                         break;
 721                 }
 722                 ishtp_hbm_dma_xfer_ack(dev, dma_xfer);
 723                 break;
 724 
 725         default:
 726                 dev_err(dev->devc, "unknown HBM: %u\n",
 727                         (unsigned int)ishtp_msg->hbm_cmd);
 728 
 729                 break;
 730         }
 731 }
 732 
 733 /**
 734  * bh_hbm_work_fn() - HBM work function
 735  * @work: work struct
 736  *
 737  * Bottom half processing work function (instead of thread handler)
 738  * for processing hbm messages
 739  */
 740 void    bh_hbm_work_fn(struct work_struct *work)
 741 {
 742         unsigned long   flags;
 743         struct ishtp_device     *dev;
 744         unsigned char   hbm[IPC_PAYLOAD_SIZE];
 745 
 746         dev = container_of(work, struct ishtp_device, bh_hbm_work);
 747         spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
 748         if (dev->rd_msg_fifo_head != dev->rd_msg_fifo_tail) {
 749                 memcpy(hbm, dev->rd_msg_fifo + dev->rd_msg_fifo_head,
 750                         IPC_PAYLOAD_SIZE);
 751                 dev->rd_msg_fifo_head =
 752                         (dev->rd_msg_fifo_head + IPC_PAYLOAD_SIZE) %
 753                         (RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
 754                 spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
 755                 ishtp_hbm_dispatch(dev, (struct ishtp_bus_message *)hbm);
 756         } else {
 757                 spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
 758         }
 759 }
 760 
 761 /**
 762  * recv_hbm() - Receive HBM message
 763  * @dev: ISHTP device instance
 764  * @ishtp_hdr: received bus message
 765  *
 766  * Receive and process ISHTP bus messages in ISR context. This will schedule
 767  * work function to process message
 768  */
 769 void    recv_hbm(struct ishtp_device *dev, struct ishtp_msg_hdr *ishtp_hdr)
 770 {
 771         uint8_t rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
 772         struct ishtp_bus_message        *ishtp_msg =
 773                 (struct ishtp_bus_message *)rd_msg_buf;
 774         unsigned long   flags;
 775 
 776         dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
 777 
 778         /* Flow control - handle in place */
 779         if (ishtp_msg->hbm_cmd == ISHTP_FLOW_CONTROL_CMD) {
 780                 struct hbm_flow_control *flow_control =
 781                         (struct hbm_flow_control *)ishtp_msg;
 782                 struct ishtp_cl *cl = NULL;
 783                 unsigned long   flags, tx_flags;
 784 
 785                 spin_lock_irqsave(&dev->cl_list_lock, flags);
 786                 list_for_each_entry(cl, &dev->cl_list, link) {
 787                         if (cl->host_client_id == flow_control->host_addr &&
 788                                         cl->fw_client_id ==
 789                                         flow_control->fw_addr) {
 790                                 /*
 791                                  * NOTE: It's valid only for counting
 792                                  * flow-control implementation to receive a
 793                                  * FC in the middle of sending. Meanwhile not
 794                                  * supported
 795                                  */
 796                                 if (cl->ishtp_flow_ctrl_creds)
 797                                         dev_err(dev->devc,
 798                                          "recv extra FC from FW client %u (host client %u) (FC count was %d)\n",
 799                                          (unsigned int)cl->fw_client_id,
 800                                          (unsigned int)cl->host_client_id,
 801                                          cl->ishtp_flow_ctrl_creds);
 802                                 else {
 803                                         ++cl->ishtp_flow_ctrl_creds;
 804                                         ++cl->ishtp_flow_ctrl_cnt;
 805                                         cl->last_ipc_acked = 1;
 806                                         spin_lock_irqsave(
 807                                                         &cl->tx_list_spinlock,
 808                                                         tx_flags);
 809                                         if (!list_empty(&cl->tx_list.list)) {
 810                                                 /*
 811                                                  * start sending the first msg
 812                                                  *      = the callback function
 813                                                  */
 814                                                 spin_unlock_irqrestore(
 815                                                         &cl->tx_list_spinlock,
 816                                                         tx_flags);
 817                                                 ishtp_cl_send_msg(dev, cl);
 818                                         } else {
 819                                                 spin_unlock_irqrestore(
 820                                                         &cl->tx_list_spinlock,
 821                                                         tx_flags);
 822                                         }
 823                                 }
 824                                 break;
 825                         }
 826                 }
 827                 spin_unlock_irqrestore(&dev->cl_list_lock, flags);
 828                 goto    eoi;
 829         }
 830 
 831         /*
 832          * Some messages that are safe for ISR processing and important
 833          * to be done "quickly" and in-order, go here
 834          */
 835         if (ishtp_msg->hbm_cmd == CLIENT_CONNECT_RES_CMD ||
 836                         ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_RES_CMD ||
 837                         ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_REQ_CMD ||
 838                         ishtp_msg->hbm_cmd == DMA_XFER) {
 839                 ishtp_hbm_dispatch(dev, ishtp_msg);
 840                 goto    eoi;
 841         }
 842 
 843         /*
 844          * All other HBMs go here.
 845          * We schedule HBMs for processing serially by using system wq,
 846          * possibly there will be multiple HBMs scheduled at the same time.
 847          */
 848         spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
 849         if ((dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
 850                         (RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE) ==
 851                         dev->rd_msg_fifo_head) {
 852                 spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
 853                 dev_err(dev->devc, "BH buffer overflow, dropping HBM %u\n",
 854                         (unsigned int)ishtp_msg->hbm_cmd);
 855                 goto    eoi;
 856         }
 857         memcpy(dev->rd_msg_fifo + dev->rd_msg_fifo_tail, ishtp_msg,
 858                 ishtp_hdr->length);
 859         dev->rd_msg_fifo_tail = (dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
 860                 (RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
 861         spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
 862         schedule_work(&dev->bh_hbm_work);
 863 eoi:
 864         return;
 865 }
 866 
 867 /**
 868  * recv_fixed_cl_msg() - Receive fixed client message
 869  * @dev: ISHTP device instance
 870  * @ishtp_hdr: received bus message
 871  *
 872  * Receive and process ISHTP fixed client messages (address == 0)
 873  * in ISR context
 874  */
 875 void recv_fixed_cl_msg(struct ishtp_device *dev,
 876         struct ishtp_msg_hdr *ishtp_hdr)
 877 {
 878         uint8_t rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
 879 
 880         dev->print_log(dev,
 881                 "%s() got fixed client msg from client #%d\n",
 882                 __func__, ishtp_hdr->fw_addr);
 883         dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
 884         if (ishtp_hdr->fw_addr == ISHTP_SYSTEM_STATE_CLIENT_ADDR) {
 885                 struct ish_system_states_header *msg_hdr =
 886                         (struct ish_system_states_header *)rd_msg_buf;
 887                 if (msg_hdr->cmd == SYSTEM_STATE_SUBSCRIBE)
 888                         ishtp_send_resume(dev);
 889                 /* if FW request arrived here, the system is not suspended */
 890                 else
 891                         dev_err(dev->devc, "unknown fixed client msg [%02X]\n",
 892                                 msg_hdr->cmd);
 893         }
 894 }
 895 
 896 /**
 897  * fix_cl_hdr() - Initialize fixed client header
 898  * @hdr: message header
 899  * @length: length of message
 900  * @cl_addr: Client address
 901  *
 902  * Initialize message header for fixed client
 903  */
 904 static inline void fix_cl_hdr(struct ishtp_msg_hdr *hdr, size_t length,
 905         uint8_t cl_addr)
 906 {
 907         hdr->host_addr = 0;
 908         hdr->fw_addr = cl_addr;
 909         hdr->length = length;
 910         hdr->msg_complete = 1;
 911         hdr->reserved = 0;
 912 }
 913 
 914 /*** Suspend and resume notification ***/
 915 
 916 static uint32_t current_state;
 917 static uint32_t supported_states = 0 | SUSPEND_STATE_BIT;
 918 
 919 /**
 920  * ishtp_send_suspend() - Send suspend message to FW
 921  * @dev: ISHTP device instance
 922  *
 923  * Send suspend message to FW. This is useful for system freeze (non S3) case
 924  */
 925 void ishtp_send_suspend(struct ishtp_device *dev)
 926 {
 927         struct ishtp_msg_hdr    ishtp_hdr;
 928         struct ish_system_states_status state_status_msg;
 929         const size_t len = sizeof(struct ish_system_states_status);
 930 
 931         fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
 932 
 933         memset(&state_status_msg, 0, len);
 934         state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
 935         state_status_msg.supported_states = supported_states;
 936         current_state |= SUSPEND_STATE_BIT;
 937         dev->print_log(dev, "%s() sends SUSPEND notification\n", __func__);
 938         state_status_msg.states_status = current_state;
 939 
 940         ishtp_write_message(dev, &ishtp_hdr,
 941                 (unsigned char *)&state_status_msg);
 942 }
 943 EXPORT_SYMBOL(ishtp_send_suspend);
 944 
 945 /**
 946  * ishtp_send_resume() - Send resume message to FW
 947  * @dev: ISHTP device instance
 948  *
 949  * Send resume message to FW. This is useful for system freeze (non S3) case
 950  */
 951 void ishtp_send_resume(struct ishtp_device *dev)
 952 {
 953         struct ishtp_msg_hdr    ishtp_hdr;
 954         struct ish_system_states_status state_status_msg;
 955         const size_t len = sizeof(struct ish_system_states_status);
 956 
 957         fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
 958 
 959         memset(&state_status_msg, 0, len);
 960         state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
 961         state_status_msg.supported_states = supported_states;
 962         current_state &= ~SUSPEND_STATE_BIT;
 963         dev->print_log(dev, "%s() sends RESUME notification\n", __func__);
 964         state_status_msg.states_status = current_state;
 965 
 966         ishtp_write_message(dev, &ishtp_hdr,
 967                 (unsigned char *)&state_status_msg);
 968 }
 969 EXPORT_SYMBOL(ishtp_send_resume);
 970 
 971 /**
 972  * ishtp_query_subscribers() - Send query subscribers message
 973  * @dev: ISHTP device instance
 974  *
 975  * Send message to query subscribers
 976  */
 977 void ishtp_query_subscribers(struct ishtp_device *dev)
 978 {
 979         struct ishtp_msg_hdr    ishtp_hdr;
 980         struct ish_system_states_query_subscribers query_subscribers_msg;
 981         const size_t len = sizeof(struct ish_system_states_query_subscribers);
 982 
 983         fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
 984 
 985         memset(&query_subscribers_msg, 0, len);
 986         query_subscribers_msg.hdr.cmd = SYSTEM_STATE_QUERY_SUBSCRIBERS;
 987 
 988         ishtp_write_message(dev, &ishtp_hdr,
 989                 (unsigned char *)&query_subscribers_msg);
 990 }