drivers/staging/mei/interface.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2012, 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  * This function returns -EIO if write has failed
 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 -EIO;
 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 -EIO;
 181
 182         return 0;
 183 }
 184
 185 /**
 186  * mei_count_full_read_slots - counts read full slots.
 187  *
 188  * @dev: the device structure
 189  *
 190  * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise filled slots count
 191  */
 192 int mei_count_full_read_slots(struct mei_device *dev)
 193 {
 194         char read_ptr, write_ptr;
 195         unsigned char buffer_depth, filled_slots;
 196
 197         dev->me_hw_state = mei_mecsr_read(dev);
 198         buffer_depth = (unsigned char)((dev->me_hw_state & ME_CBD_HRA) >> 24);
 199         read_ptr = (char) ((dev->me_hw_state & ME_CBRP_HRA) >> 8);
 200         write_ptr = (char) ((dev->me_hw_state & ME_CBWP_HRA) >> 16);
 201         filled_slots = (unsigned char) (write_ptr - read_ptr);
 202
 203         /* check for overflow */
 204         if (filled_slots > buffer_depth)
 205                 return -EOVERFLOW;
 206
 207         dev_dbg(&dev->pdev->dev, "filled_slots =%08x\n", filled_slots);
 208         return (int)filled_slots;
 209 }
 210
 211 /**
 212  * mei_read_slots - reads a message from mei device.
 213  *
 214  * @dev: the device structure
 215  * @buffer: message buffer will be written
 216  * @buffer_length: message size will be read
 217  */
 218 void mei_read_slots(struct mei_device *dev, unsigned char *buffer,
 219                     unsigned long buffer_length)
 220 {
 221         u32 *reg_buf = (u32 *)buffer;
 222
 223         for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
 224                 *reg_buf++ = mei_mecbrw_read(dev);
 225
 226         if (buffer_length > 0) {
 227                 u32 reg = mei_mecbrw_read(dev);
 228                 memcpy(reg_buf, &reg, buffer_length);
 229         }
 230
 231         dev->host_hw_state |= H_IG;
 232         mei_hcsr_set(dev);
 233 }
 234
 235 /**
 236  * mei_flow_ctrl_creds - checks flow_control credentials.
 237  *
 238  * @dev: the device structure
 239  * @cl: private data of the file object
 240  *
 241  * returns 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
 242  *      -ENOENT if mei_cl is not present
 243  *      -EINVAL if single_recv_buf == 0
 244  */
 245 int mei_flow_ctrl_creds(struct mei_device *dev, struct mei_cl *cl)
 246 {
 247         int i;
 248
 249         if (!dev->me_clients_num)
 250                 return 0;
 251
 252         if (cl->mei_flow_ctrl_creds > 0)
 253                 return 1;
 254
 255         for (i = 0; i < dev->me_clients_num; i++) {
 256                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 257                 if (me_cl->client_id == cl->me_client_id) {
 258                         if (me_cl->mei_flow_ctrl_creds) {
 259                                 if (WARN_ON(me_cl->props.single_recv_buf == 0))
 260                                         return -EINVAL;
 261                                 return 1;
 262                         } else {
 263                                 return 0;
 264                         }
 265                 }
 266         }
 267         return -ENOENT;
 268 }
 269
 270 /**
 271  * mei_flow_ctrl_reduce - reduces flow_control.
 272  *
 273  * @dev: the device structure
 274  * @cl: private data of the file object
 275  * @returns
 276  *      0 on success
 277  *      -ENOENT when me client is not found
 278  *      -EINVAL when ctrl credits are <= 0
 279  */
 280 int mei_flow_ctrl_reduce(struct mei_device *dev, struct mei_cl *cl)
 281 {
 282         int i;
 283
 284         if (!dev->me_clients_num)
 285                 return -ENOENT;
 286
 287         for (i = 0; i < dev->me_clients_num; i++) {
 288                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 289                 if (me_cl->client_id == cl->me_client_id) {
 290                         if (me_cl->props.single_recv_buf != 0) {
 291                                 if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
 292                                         return -EINVAL;
 293                                 dev->me_clients[i].mei_flow_ctrl_creds--;
 294                         } else {
 295                                 if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
 296                                         return -EINVAL;
 297                                 cl->mei_flow_ctrl_creds--;
 298                         }
 299                         return 0;
 300                 }
 301         }
 302         return -ENOENT;
 303 }
 304
 305 /**
 306  * mei_send_flow_control - sends flow control to fw.
 307  *
 308  * @dev: the device structure
 309  * @cl: private data of the file object
 310  *
 311  * This function returns -EIO on write failure
 312  */
 313 int mei_send_flow_control(struct mei_device *dev, struct mei_cl *cl)
 314 {
 315         struct mei_msg_hdr *mei_hdr;
 316         struct hbm_flow_control *mei_flow_control;
 317
 318         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 319         mei_hdr->host_addr = 0;
 320         mei_hdr->me_addr = 0;
 321         mei_hdr->length = sizeof(struct hbm_flow_control);
 322         mei_hdr->msg_complete = 1;
 323         mei_hdr->reserved = 0;
 324
 325         mei_flow_control = (struct hbm_flow_control *) &dev->wr_msg_buf[1];
 326         memset(mei_flow_control, 0, sizeof(*mei_flow_control));
 327         mei_flow_control->host_addr = cl->host_client_id;
 328         mei_flow_control->me_addr = cl->me_client_id;
 329         mei_flow_control->hbm_cmd = MEI_FLOW_CONTROL_CMD;
 330         memset(mei_flow_control->reserved, 0,
 331                         sizeof(mei_flow_control->reserved));
 332         dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
 333                 cl->host_client_id, cl->me_client_id);
 334
 335         return mei_write_message(dev, mei_hdr,
 336                                 (unsigned char *) mei_flow_control,
 337                                 sizeof(struct hbm_flow_control));
 338 }
 339
 340 /**
 341  * mei_other_client_is_connecting - checks if other
 342  *    client with the same client id is connected.
 343  *
 344  * @dev: the device structure
 345  * @cl: private data of the file object
 346  *
 347  * returns 1 if other client is connected, 0 - otherwise.
 348  */
 349 int mei_other_client_is_connecting(struct mei_device *dev,
 350                                 struct mei_cl *cl)
 351 {
 352         struct mei_cl *cl_pos = NULL;
 353         struct mei_cl *cl_next = NULL;
 354
 355         list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
 356                 if ((cl_pos->state == MEI_FILE_CONNECTING) &&
 357                         (cl_pos != cl) &&
 358                         cl->me_client_id == cl_pos->me_client_id)
 359                         return 1;
 360
 361         }
 362         return 0;
 363 }
 364
 365 /**
 366  * mei_disconnect - sends disconnect message to fw.
 367  *
 368  * @dev: the device structure
 369  * @cl: private data of the file object
 370  *
 371  * This function returns -EIO on write failure
 372  */
 373 int mei_disconnect(struct mei_device *dev, struct mei_cl *cl)
 374 {
 375         struct mei_msg_hdr *mei_hdr;
 376         struct hbm_client_disconnect_request *mei_cli_disconnect;
 377
 378         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 379         mei_hdr->host_addr = 0;
 380         mei_hdr->me_addr = 0;
 381         mei_hdr->length = sizeof(struct hbm_client_disconnect_request);
 382         mei_hdr->msg_complete = 1;
 383         mei_hdr->reserved = 0;
 384
 385         mei_cli_disconnect =
 386             (struct hbm_client_disconnect_request *) &dev->wr_msg_buf[1];
 387         memset(mei_cli_disconnect, 0, sizeof(*mei_cli_disconnect));
 388         mei_cli_disconnect->host_addr = cl->host_client_id;
 389         mei_cli_disconnect->me_addr = cl->me_client_id;
 390         mei_cli_disconnect->hbm_cmd = CLIENT_DISCONNECT_REQ_CMD;
 391         mei_cli_disconnect->reserved[0] = 0;
 392
 393         return mei_write_message(dev, mei_hdr,
 394                                 (unsigned char *) mei_cli_disconnect,
 395                                 sizeof(struct hbm_client_disconnect_request));
 396 }
 397
 398 /**
 399  * mei_connect - sends connect message to fw.
 400  *
 401  * @dev: the device structure
 402  * @cl: private data of the file object
 403  *
 404  * This function returns -EIO on write failure
 405  */
 406 int mei_connect(struct mei_device *dev, struct mei_cl *cl)
 407 {
 408         struct mei_msg_hdr *mei_hdr;
 409         struct hbm_client_connect_request *mei_cli_connect;
 410
 411         mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
 412         mei_hdr->host_addr = 0;
 413         mei_hdr->me_addr = 0;
 414         mei_hdr->length = sizeof(struct hbm_client_connect_request);
 415         mei_hdr->msg_complete = 1;
 416         mei_hdr->reserved = 0;
 417
 418         mei_cli_connect =
 419             (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
 420         mei_cli_connect->host_addr = cl->host_client_id;
 421         mei_cli_connect->me_addr = cl->me_client_id;
 422         mei_cli_connect->hbm_cmd = CLIENT_CONNECT_REQ_CMD;
 423         mei_cli_connect->reserved = 0;
 424
 425         return mei_write_message(dev, mei_hdr,
 426                                 (unsigned char *) mei_cli_connect,
 427                                 sizeof(struct hbm_client_connect_request));
 428 }