drivers/staging/mei/interface.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2011, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  */
  16
  17 #include <linux/pci.h>
  18 #include "mei_dev.h"
  19 #include "mei.h"
  20 #include "interface.h"
  21
  22
  23
  24 /**
  25  * mei_set_csr_register - writes H_CSR register to the mei device,
  26  * and ignores the H_IS bit for it is write-one-to-zero.
  27  *
  28  * @dev: the device structure
  29  */
  30 void mei_hcsr_set(struct mei_device *dev)
  31 {
  32         if ((dev->host_hw_state & H_IS) == H_IS)
  33                 dev->host_hw_state &= ~H_IS;
  34         mei_reg_write(dev, H_CSR, dev->host_hw_state);
  35         dev->host_hw_state = mei_hcsr_read(dev);
  36 }
  37
  38 /**
  39  * mei_csr_enable_interrupts - enables mei device interrupts
  40  *
  41  * @dev: the device structure
  42  */
  43 void mei_enable_interrupts(struct mei_device *dev)
  44 {
  45         dev->host_hw_state |= H_IE;
  46         mei_hcsr_set(dev);
  47 }
  48
  49 /**
  50  * mei_csr_disable_interrupts - disables mei device interrupts
  51  *
  52  * @dev: the device structure
  53  */
  54 void mei_disable_interrupts(struct mei_device *dev)
  55 {
  56         dev->host_hw_state &= ~H_IE;
  57         mei_hcsr_set(dev);
  58 }
  59
  60 /**
  61  * _host_get_filled_slots - gets number of device filled buffer slots
  62  *
  63  * @device: the device structure
  64  *
  65  * returns number of filled slots
  66  */
  67 static unsigned char _host_get_filled_slots(const struct mei_device *dev)
  68 {
  69         char read_ptr, write_ptr;
  70
  71         read_ptr = (char) ((dev->host_hw_state & H_CBRP) >> 8);
  72         write_ptr = (char) ((dev->host_hw_state & H_CBWP) >> 16);
  73
  74         return (unsigned char) (write_ptr - read_ptr);
  75 }
  76
  77 /**
  78  * mei_host_buffer_is_empty - checks if host buffer is empty.
  79  *
  80  * @dev: the device structure
  81  *
  82  * returns 1 if empty, 0 - otherwise.
  83  */
  84 int mei_host_buffer_is_empty(struct mei_device *dev)
  85 {
  86         unsigned char filled_slots;
  87
  88         dev->host_hw_state = mei_hcsr_read(dev);
  89         filled_slots = _host_get_filled_slots(dev);
  90
  91         if (filled_slots == 0)
  92                 return 1;
  93
  94         return 0;
  95 }
  96
  97 /**
  98  * mei_count_empty_write_slots - counts write empty slots.
  99  *
 100  * @dev: the device structure
 101  *
 102  * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise empty slots count
 103  */
 104 int mei_count_empty_write_slots(struct mei_device *dev)
 105 {
 106         unsigned char buffer_depth, filled_slots, empty_slots;
 107
 108         dev->host_hw_state = mei_hcsr_read(dev);
 109         buffer_depth = (unsigned char) ((dev->host_hw_state & H_CBD) >> 24);
 110         filled_slots = _host_get_filled_slots(dev);
 111         empty_slots = buffer_depth - filled_slots;
 112
 113         /* check for overflow */
 114         if (filled_slots > buffer_depth)
 115                 return -EOVERFLOW;
 116
 117         return empty_slots;
 118 }
 119
 120 /**
 121  * mei_write_message - writes a message to mei device.
 122  *
 123  * @dev: the device structure
 124  * @header: header of message
 125  * @write_buffer: message buffer will be written
 126  * @write_length: message size will be written
 127  *
 128  * returns 1 if success, 0 - otherwise.
 129  */
 130 int mei_write_message(struct mei_device *dev,
 131                              struct mei_msg_hdr *header,
 132                              unsigned char *write_buffer,
 133                              unsigned long write_length)
 134 {
 135         u32 temp_msg = 0;
 136         unsigned long bytes_written = 0;
 137         unsigned char buffer_depth, filled_slots, empty_slots;
 138         unsigned long dw_to_write;
 139
 140         dev->host_hw_state = mei_hcsr_read(dev);
 141
 142         dev_dbg(&dev->pdev->dev,
 143                         "host_hw_state = 0x%08x.\n",
 144                         dev->host_hw_state);
 145
 146         dev_dbg(&dev->pdev->dev,
 147                         "mei_write_message header=%08x.\n",
 148                         *((u32 *) header));
 149
 150         buffer_depth = (unsigned char) ((dev->host_hw_state & H_CBD) >> 24);
 151         filled_slots = _host_get_filled_slots(dev);
 152         empty_slots = buffer_depth - filled_slots;
 153         dev_dbg(&dev->pdev->dev,
 154                         "filled = %hu, empty = %hu.\n",
 155                         filled_slots, empty_slots);
 156
 157         dw_to_write = ((write_length + 3) / 4);
 158
 159         if (dw_to_write > empty_slots)
 160                 return 0;
 161
 162         mei_reg_write(dev, H_CB_WW, *((u32 *) header));
 163
 164         while (write_length >= 4) {
 165                 mei_reg_write(dev, H_CB_WW,
 166                                 *(u32 *) (write_buffer + bytes_written));
 167                 bytes_written += 4;
 168                 write_length -= 4;
 169         }
 170
 171         if (write_length > 0) {
 172                 memcpy(&temp_msg, &write_buffer[bytes_written], write_length);
 173                 mei_reg_write(dev, H_CB_WW, temp_msg);
 174         }
 175
 176         dev->host_hw_state |= H_IG;
 177         mei_hcsr_set(dev);
 178         dev->me_hw_state = mei_mecsr_read(dev);
 179         if ((dev->me_hw_state & ME_RDY_HRA) != ME_RDY_HRA)
 180                 return 0;
 181
 182         dev->write_hang = 0;
 183         return 1;
 184 }
 185
 186 /**
 187  * mei_count_full_read_slots - counts read full slots.
 188  *
 189  * @dev: the device structure
 190  *
 191  * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise filled slots count
 192  */
 193 int mei_count_full_read_slots(struct mei_device *dev)
 194 {
 195         char read_ptr, write_ptr;
 196         unsigned char buffer_depth, filled_slots;
 197
 198         dev->me_hw_state = mei_mecsr_read(dev);
 199         buffer_depth = (unsigned char)((dev->me_hw_state & ME_CBD_HRA) >> 24);
 200         read_ptr = (char) ((dev->me_hw_state & ME_CBRP_HRA) >> 8);
 201         write_ptr = (char) ((dev->me_hw_state & ME_CBWP_HRA) >> 16);
 202         filled_slots = (unsigned char) (write_ptr - read_ptr);
 203
 204         /* check for overflow */
 205         if (filled_slots > buffer_depth)
 206                 return -EOVERFLOW;
 207
 208         dev_dbg(&dev->pdev->dev, "filled_slots =%08x\n", filled_slots);
 209         return (int)filled_slots;
 210 }
 211
 212 /**
 213  * mei_read_slots - reads a message from mei device.
 214  *
 215  * @dev: the device structure
 216  * @buffer: message buffer will be written
 217  * @buffer_length: message size will be read
 218  */
 219 void mei_read_slots(struct mei_device *dev,
 220                      unsigned char *buffer, unsigned long buffer_length)
 221 {
 222         u32 i = 0;
 223         unsigned char temp_buf[sizeof(u32)];
 224
 225         while (buffer_length >= sizeof(u32)) {
 226                 ((u32 *) buffer)[i] = mei_mecbrw_read(dev);
 227
 228                 dev_dbg(&dev->pdev->dev,
 229                                 "buffer[%d]= %d\n",
 230                                 i, ((u32 *) buffer)[i]);
 231
 232                 i++;
 233                 buffer_length -= sizeof(u32);
 234         }
 235
 236         if (buffer_length > 0) {
 237                 *((u32 *) &temp_buf) = mei_mecbrw_read(dev);
 238                 memcpy(&buffer[i * 4], temp_buf, buffer_length);
 239         }
 240
 241         dev->host_hw_state |= H_IG;
 242         mei_hcsr_set(dev);
 243 }
 244
 245 /**
 246  * mei_flow_ctrl_creds - checks flow_control credentials.
 247  *
 248  * @dev: the device structure
 249  * @cl: private data of the file object
 250  *
 251  * returns 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
 252  *      -ENOENT if mei_cl is not present
 253  *      -EINVAL if single_recv_buf == 0
 254  */
 255 int mei_flow_ctrl_creds(struct mei_device *dev, struct mei_cl *cl)
 256 {
 257         int i;
 258
 259         if (!dev->num_mei_me_clients)
 260                 return 0;
 261
 262         if (cl->mei_flow_ctrl_creds > 0)
 263                 return 1;
 264
 265         for (i = 0; i < dev->num_mei_me_clients; i++) {
 266                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 267                 if (me_cl->client_id == cl->me_client_id) {
 268                         if (me_cl->mei_flow_ctrl_creds) {
 269                                 if (WARN_ON(me_cl->props.single_recv_buf == 0))
 270                                         return -EINVAL;
 271                                 return 1;
 272                         } else {
 273                                 return 0;
 274                         }
 275                 }
 276         }
 277         return -ENOENT;
 278 }
 279
 280 /**
 281  * mei_flow_ctrl_reduce - reduces flow_control.
 282  *
 283  * @dev: the device structure
 284  * @cl: private data of the file object
 285  * @returns
 286  *      0 on success
 287  *      -ENOENT when me client is not found
 288  *      -EINVAL wehn ctrl credits are <= 0
 289  */
 290 int mei_flow_ctrl_reduce(struct mei_device *dev, struct mei_cl *cl)
 291 {
 292         int i;
 293
 294         if (!dev->num_mei_me_clients)
 295                 return -ENOENT;
 296
 297         for (i = 0; i < dev->num_mei_me_clients; i++) {
 298                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 299                 if (me_cl->client_id == cl->me_client_id) {
 300                         if (me_cl->props.single_recv_buf != 0) {
 301                                 if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
 302                                         return -EINVAL;
 303                                 dev->me_clients[i].mei_flow_ctrl_creds--;
 304                         } else {
 305                                 if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
 306                                         return -EINVAL;
 307                                 cl->mei_flow_ctrl_creds--;
 308                         }
 309                         return 0;
 310                 }
 311         }
 312         return -ENOENT;
 313 }
 314
 315 /**
 316  * mei_send_flow_control - sends flow control to fw.
 317  *
 318  * @dev: the device structure
 319  * @cl: private data of the file object
 320  *
 321  * returns 1 if success, 0 - otherwise.
 322  */
 323 int mei_send_flow_control(struct mei_device *dev, struct mei_cl *cl)
 324 {
 325         struct mei_msg_hdr *mei_hdr;
 326         struct hbm_flow_control *mei_flow_control;
 327
 328         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 329         mei_hdr->host_addr = 0;
 330         mei_hdr->me_addr = 0;
 331         mei_hdr->length = sizeof(struct hbm_flow_control);
 332         mei_hdr->msg_complete = 1;
 333         mei_hdr->reserved = 0;
 334
 335         mei_flow_control = (struct hbm_flow_control *) &dev->wr_msg_buf[1];
 336         memset(mei_flow_control, 0, sizeof(mei_flow_control));
 337         mei_flow_control->host_addr = cl->host_client_id;
 338         mei_flow_control->me_addr = cl->me_client_id;
 339         mei_flow_control->cmd.cmd = MEI_FLOW_CONTROL_CMD;
 340         memset(mei_flow_control->reserved, 0,
 341                         sizeof(mei_flow_control->reserved));
 342         dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
 343             cl->host_client_id, cl->me_client_id);
 344         if (!mei_write_message(dev, mei_hdr,
 345                                 (unsigned char *) mei_flow_control,
 346                                 sizeof(struct hbm_flow_control)))
 347                 return 0;
 348
 349         return 1;
 350
 351 }
 352
 353 /**
 354  * mei_other_client_is_connecting - checks if other
 355  *    client with the same client id is connected.
 356  *
 357  * @dev: the device structure
 358  * @cl: private data of the file object
 359  *
 360  * returns 1 if other client is connected, 0 - otherwise.
 361  */
 362 int mei_other_client_is_connecting(struct mei_device *dev,
 363                                 struct mei_cl *cl)
 364 {
 365         struct mei_cl *cl_pos = NULL;
 366         struct mei_cl *cl_next = NULL;
 367
 368         list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
 369                 if ((cl_pos->state == MEI_FILE_CONNECTING) &&
 370                         (cl_pos != cl) &&
 371                         cl->me_client_id == cl_pos->me_client_id)
 372                         return 1;
 373
 374         }
 375         return 0;
 376 }
 377
 378 /**
 379  * mei_disconnect - sends disconnect message to fw.
 380  *
 381  * @dev: the device structure
 382  * @cl: private data of the file object
 383  *
 384  * returns 1 if success, 0 - otherwise.
 385  */
 386 int mei_disconnect(struct mei_device *dev, struct mei_cl *cl)
 387 {
 388         struct mei_msg_hdr *mei_hdr;
 389         struct hbm_client_disconnect_request *mei_cli_disconnect;
 390
 391         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 392         mei_hdr->host_addr = 0;
 393         mei_hdr->me_addr = 0;
 394         mei_hdr->length = sizeof(struct hbm_client_disconnect_request);
 395         mei_hdr->msg_complete = 1;
 396         mei_hdr->reserved = 0;
 397
 398         mei_cli_disconnect =
 399             (struct hbm_client_disconnect_request *) &dev->wr_msg_buf[1];
 400         memset(mei_cli_disconnect, 0, sizeof(mei_cli_disconnect));
 401         mei_cli_disconnect->host_addr = cl->host_client_id;
 402         mei_cli_disconnect->me_addr = cl->me_client_id;
 403         mei_cli_disconnect->cmd.cmd = CLIENT_DISCONNECT_REQ_CMD;
 404         mei_cli_disconnect->reserved[0] = 0;
 405
 406         if (!mei_write_message(dev, mei_hdr,
 407                                 (unsigned char *) mei_cli_disconnect,
 408                                 sizeof(struct hbm_client_disconnect_request)))
 409                 return 0;
 410
 411         return 1;
 412 }
 413
 414 /**
 415  * mei_connect - sends connect message to fw.
 416  *
 417  * @dev: the device structure
 418  * @cl: private data of the file object
 419  *
 420  * returns 1 if success, 0 - otherwise.
 421  */
 422 int mei_connect(struct mei_device *dev, struct mei_cl *cl)
 423 {
 424         struct mei_msg_hdr *mei_hdr;
 425         struct hbm_client_connect_request *mei_cli_connect;
 426
 427         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 428         mei_hdr->host_addr = 0;
 429         mei_hdr->me_addr = 0;
 430         mei_hdr->length = sizeof(struct hbm_client_connect_request);
 431         mei_hdr->msg_complete = 1;
 432         mei_hdr->reserved = 0;
 433
 434         mei_cli_connect =
 435             (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
 436         mei_cli_connect->host_addr = cl->host_client_id;
 437         mei_cli_connect->me_addr = cl->me_client_id;
 438         mei_cli_connect->cmd.cmd = CLIENT_CONNECT_REQ_CMD;
 439         mei_cli_connect->reserved = 0;
 440
 441         if (!mei_write_message(dev, mei_hdr,
 442                                 (unsigned char *) mei_cli_connect,
 443                                 sizeof(struct hbm_client_connect_request)))
 444                 return 0;
 445
 446         return 1;
 447 }