drivers/misc/mei/amthif.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/kernel.h>
  18 #include <linux/fs.h>
  19 #include <linux/errno.h>
  20 #include <linux/types.h>
  21 #include <linux/fcntl.h>
  22 #include <linux/ioctl.h>
  23 #include <linux/cdev.h>
  24 #include <linux/list.h>
  25 #include <linux/delay.h>
  26 #include <linux/sched.h>
  27 #include <linux/uuid.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/slab.h>
  31
  32 #include <linux/mei.h>
  33
  34 #include "mei_dev.h"
  35 #include "hbm.h"
  36 #include "client.h"
  37
  38 const uuid_le mei_amthif_guid  = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d,
  39                                          0xac, 0xa8, 0x46, 0xe0,
  40                                          0xff, 0x65, 0x81, 0x4c);
  41
  42 /**
  43  * mei_amthif_reset_params - initializes mei device iamthif
  44  *
  45  * @dev: the device structure
  46  */
  47 void mei_amthif_reset_params(struct mei_device *dev)
  48 {
  49         /* reset iamthif parameters. */
  50         dev->iamthif_current_cb = NULL;
  51         dev->iamthif_canceled = false;
  52         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  53         dev->iamthif_stall_timer = 0;
  54         dev->iamthif_open_count = 0;
  55 }
  56
  57 /**
  58  * mei_amthif_host_init - mei initialization amthif client.
  59  *
  60  * @dev: the device structure
  61  * @me_cl: me client
  62  *
  63  * Return: 0 on success, <0 on failure.
  64  */
  65 int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
  66 {
  67         struct mei_cl *cl = &dev->iamthif_cl;
  68         int ret;
  69
  70         if (mei_cl_is_connected(cl))
  71                 return 0;
  72
  73         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  74
  75         mei_cl_init(cl, dev);
  76
  77         ret = mei_cl_link(cl);
  78         if (ret < 0) {
  79                 dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
  80                 return ret;
  81         }
  82
  83         ret = mei_cl_connect(cl, me_cl, NULL);
  84
  85         return ret;
  86 }
  87
  88 /**
  89  * mei_amthif_read - read data from AMTHIF client
  90  *
  91  * @dev: the device structure
  92  * @file: pointer to file object
  93  * @ubuf: pointer to user data in user space
  94  * @length: data length to read
  95  * @offset: data read offset
  96  *
  97  * Locking: called under "dev->device_lock" lock
  98  *
  99  * Return:
 100  *  returned data length on success,
 101  *  zero if no data to read,
 102  *  negative on failure.
 103  */
 104 int mei_amthif_read(struct mei_device *dev, struct file *file,
 105                char __user *ubuf, size_t length, loff_t *offset)
 106 {
 107         struct mei_cl *cl = file->private_data;
 108         struct mei_cl_cb *cb;
 109         int rets;
 110         int wait_ret;
 111
 112         dev_dbg(dev->dev, "checking amthif data\n");
 113         cb = mei_cl_read_cb(cl, file);
 114
 115         /* Check for if we can block or not*/
 116         if (cb == NULL && file->f_flags & O_NONBLOCK)
 117                 return -EAGAIN;
 118
 119
 120         dev_dbg(dev->dev, "waiting for amthif data\n");
 121         while (cb == NULL) {
 122                 /* unlock the Mutex */
 123                 mutex_unlock(&dev->device_lock);
 124
 125                 wait_ret = wait_event_interruptible(cl->rx_wait,
 126                                         !list_empty(&cl->rd_completed) ||
 127                                         !mei_cl_is_connected(cl));
 128
 129                 /* Locking again the Mutex */
 130                 mutex_lock(&dev->device_lock);
 131
 132                 if (wait_ret)
 133                         return -ERESTARTSYS;
 134
 135                 if (!mei_cl_is_connected(cl)) {
 136                         rets = -EBUSY;
 137                         goto out;
 138                 }
 139
 140                 cb = mei_cl_read_cb(cl, file);
 141         }
 142
 143         if (cb->status) {
 144                 rets = cb->status;
 145                 dev_dbg(dev->dev, "read operation failed %d\n", rets);
 146                 goto free;
 147         }
 148
 149         dev_dbg(dev->dev, "Got amthif data\n");
 150         /* if the whole message will fit remove it from the list */
 151         if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
 152                 list_del_init(&cb->list);
 153         else if (cb->buf_idx <= *offset) {
 154                 /* end of the message has been reached */
 155                 list_del_init(&cb->list);
 156                 rets = 0;
 157                 goto free;
 158         }
 159                 /* else means that not full buffer will be read and do not
 160                  * remove message from deletion list
 161                  */
 162
 163         dev_dbg(dev->dev, "amthif cb->buf.size - %zu cb->buf_idx - %zu\n",
 164                 cb->buf.size, cb->buf_idx);
 165
 166         /* length is being truncated to PAGE_SIZE, however,
 167          * the buf_idx may point beyond */
 168         length = min_t(size_t, length, (cb->buf_idx - *offset));
 169
 170         if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
 171                 dev_dbg(dev->dev, "failed to copy data to userland\n");
 172                 rets = -EFAULT;
 173         } else {
 174                 rets = length;
 175                 if ((*offset + length) < cb->buf_idx) {
 176                         *offset += length;
 177                         goto out;
 178                 }
 179         }
 180 free:
 181         dev_dbg(dev->dev, "free amthif cb memory.\n");
 182         *offset = 0;
 183         mei_io_cb_free(cb);
 184 out:
 185         return rets;
 186 }
 187
 188 /**
 189  * mei_amthif_read_start - queue message for sending read credential
 190  *
 191  * @cl: host client
 192  * @file: file pointer of message recipient
 193  *
 194  * Return: 0 on success, <0 on failure.
 195  */
 196 static int mei_amthif_read_start(struct mei_cl *cl, const struct file *file)
 197 {
 198         struct mei_device *dev = cl->dev;
 199         struct mei_cl_cb *cb;
 200         int rets;
 201
 202         cb = mei_io_cb_init(cl, MEI_FOP_READ, file);
 203         if (!cb) {
 204                 rets = -ENOMEM;
 205                 goto err;
 206         }
 207
 208         rets = mei_io_cb_alloc_buf(cb, mei_cl_mtu(cl));
 209         if (rets)
 210                 goto err;
 211
 212         list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 213
 214         dev->iamthif_state = MEI_IAMTHIF_READING;
 215         dev->iamthif_fp = cb->fp;
 216         dev->iamthif_current_cb = cb;
 217
 218         return 0;
 219 err:
 220         mei_io_cb_free(cb);
 221         return rets;
 222 }
 223
 224 /**
 225  * mei_amthif_send_cmd - send amthif command to the ME
 226  *
 227  * @cl: the host client
 228  * @cb: mei call back struct
 229  *
 230  * Return: 0 on success, <0 on failure.
 231  */
 232 static int mei_amthif_send_cmd(struct mei_cl *cl, struct mei_cl_cb *cb)
 233 {
 234         struct mei_device *dev;
 235         int ret;
 236
 237         if (!cl->dev || !cb)
 238                 return -ENODEV;
 239
 240         dev = cl->dev;
 241
 242         dev->iamthif_state = MEI_IAMTHIF_WRITING;
 243         dev->iamthif_current_cb = cb;
 244         dev->iamthif_fp = cb->fp;
 245         dev->iamthif_canceled = false;
 246
 247         ret = mei_cl_write(cl, cb, false);
 248         if (ret < 0)
 249                 return ret;
 250
 251         if (cb->completed)
 252                 cb->status = mei_amthif_read_start(cl, cb->fp);
 253
 254         return 0;
 255 }
 256
 257 /**
 258  * mei_amthif_run_next_cmd - send next amt command from queue
 259  *
 260  * @dev: the device structure
 261  *
 262  * Return: 0 on success, <0 on failure.
 263  */
 264 int mei_amthif_run_next_cmd(struct mei_device *dev)
 265 {
 266         struct mei_cl *cl = &dev->iamthif_cl;
 267         struct mei_cl_cb *cb;
 268
 269         dev->iamthif_canceled = false;
 270         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 271         dev->iamthif_fp = NULL;
 272
 273         dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
 274
 275         cb = list_first_entry_or_null(&dev->amthif_cmd_list.list,
 276                                         typeof(*cb), list);
 277         if (!cb)
 278                 return 0;
 279
 280         list_del_init(&cb->list);
 281         return mei_amthif_send_cmd(cl, cb);
 282 }
 283
 284 /**
 285  * mei_amthif_write - write amthif data to amthif client
 286  *
 287  * @cl: host client
 288  * @cb: mei call back struct
 289  *
 290  * Return: 0 on success, <0 on failure.
 291  */
 292 int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 293 {
 294
 295         struct mei_device *dev = cl->dev;
 296
 297         list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
 298
 299         /*
 300          * The previous request is still in processing, queue this one.
 301          */
 302         if (dev->iamthif_state > MEI_IAMTHIF_IDLE &&
 303             dev->iamthif_state < MEI_IAMTHIF_READ_COMPLETE)
 304                 return 0;
 305
 306         return mei_amthif_run_next_cmd(dev);
 307 }
 308
 309 /**
 310  * mei_amthif_poll - the amthif poll function
 311  *
 312  * @dev: the device structure
 313  * @file: pointer to file structure
 314  * @wait: pointer to poll_table structure
 315  *
 316  * Return: poll mask
 317  *
 318  * Locking: called under "dev->device_lock" lock
 319  */
 320
 321 unsigned int mei_amthif_poll(struct mei_device *dev,
 322                 struct file *file, poll_table *wait)
 323 {
 324         unsigned int mask = 0;
 325
 326         poll_wait(file, &dev->iamthif_cl.rx_wait, wait);
 327
 328         if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
 329             dev->iamthif_fp == file) {
 330
 331                 mask |= POLLIN | POLLRDNORM;
 332                 mei_amthif_run_next_cmd(dev);
 333         }
 334
 335         return mask;
 336 }
 337
 338
 339
 340 /**
 341  * mei_amthif_irq_write - write iamthif command in irq thread context.
 342  *
 343  * @cl: private data of the file object.
 344  * @cb: callback block.
 345  * @cmpl_list: complete list.
 346  *
 347  * Return: 0, OK; otherwise, error.
 348  */
 349 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 350                          struct mei_cl_cb *cmpl_list)
 351 {
 352         int ret;
 353
 354         ret = mei_cl_irq_write(cl, cb, cmpl_list);
 355         if (ret)
 356                 return ret;
 357
 358         if (cb->completed)
 359                 cb->status = mei_amthif_read_start(cl, cb->fp);
 360
 361         return 0;
 362 }
 363
 364 /**
 365  * mei_amthif_irq_read_msg - read routine after ISR to
 366  *                      handle the read amthif message
 367  *
 368  * @cl: mei client
 369  * @mei_hdr: header of amthif message
 370  * @cmpl_list: completed callbacks list
 371  *
 372  * Return: -ENODEV if cb is NULL 0 otherwise; error message is in cb->status
 373  */
 374 int mei_amthif_irq_read_msg(struct mei_cl *cl,
 375                             struct mei_msg_hdr *mei_hdr,
 376                             struct mei_cl_cb *cmpl_list)
 377 {
 378         struct mei_device *dev;
 379         int ret;
 380
 381         dev = cl->dev;
 382
 383         if (dev->iamthif_state != MEI_IAMTHIF_READING)
 384                 return 0;
 385
 386         ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 387         if (ret)
 388                 return ret;
 389
 390         if (!mei_hdr->msg_complete)
 391                 return 0;
 392
 393         dev_dbg(dev->dev, "completed amthif read.\n ");
 394         dev->iamthif_current_cb = NULL;
 395         dev->iamthif_stall_timer = 0;
 396
 397         return 0;
 398 }
 399
 400 /**
 401  * mei_amthif_complete - complete amthif callback.
 402  *
 403  * @cl: host client
 404  * @cb: callback block.
 405  */
 406 void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 407 {
 408         struct mei_device *dev = cl->dev;
 409
 410         if (cb->fop_type == MEI_FOP_WRITE) {
 411                 if (!cb->status) {
 412                         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 413                         mei_io_cb_free(cb);
 414                         return;
 415                 }
 416                 /*
 417                  * in case of error enqueue the write cb to complete read list
 418                  * so it can be propagated to the reader
 419                  */
 420                 list_add_tail(&cb->list, &cl->rd_completed);
 421                 wake_up_interruptible(&cl->rx_wait);
 422                 return;
 423         }
 424
 425         if (!dev->iamthif_canceled) {
 426                 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
 427                 dev->iamthif_stall_timer = 0;
 428                 list_add_tail(&cb->list, &cl->rd_completed);
 429                 dev_dbg(dev->dev, "amthif read completed\n");
 430         } else {
 431                 mei_amthif_run_next_cmd(dev);
 432         }
 433
 434         dev_dbg(dev->dev, "completing amthif call back.\n");
 435         wake_up_interruptible(&cl->rx_wait);
 436 }
 437
 438 /**
 439  * mei_clear_list - removes all callbacks associated with file
 440  *              from mei_cb_list
 441  *
 442  * @dev: device structure.
 443  * @file: file structure
 444  * @mei_cb_list: callbacks list
 445  *
 446  * mei_clear_list is called to clear resources associated with file
 447  * when application calls close function or Ctrl-C was pressed
 448  *
 449  * Return: true if callback removed from the list, false otherwise
 450  */
 451 static bool mei_clear_list(struct mei_device *dev,
 452                 const struct file *file, struct list_head *mei_cb_list)
 453 {
 454         struct mei_cl *cl = &dev->iamthif_cl;
 455         struct mei_cl_cb *cb, *next;
 456         bool removed = false;
 457
 458         /* list all list member */
 459         list_for_each_entry_safe(cb, next, mei_cb_list, list) {
 460                 /* check if list member associated with a file */
 461                 if (file == cb->fp) {
 462                         /* check if cb equal to current iamthif cb */
 463                         if (dev->iamthif_current_cb == cb) {
 464                                 dev->iamthif_current_cb = NULL;
 465                                 /* send flow control to iamthif client */
 466                                 mei_hbm_cl_flow_control_req(dev, cl);
 467                         }
 468                         /* free all allocated buffers */
 469                         mei_io_cb_free(cb);
 470                         removed = true;
 471                 }
 472         }
 473         return removed;
 474 }
 475
 476 /**
 477  * mei_clear_lists - removes all callbacks associated with file
 478  *
 479  * @dev: device structure
 480  * @file: file structure
 481  *
 482  * mei_clear_lists is called to clear resources associated with file
 483  * when application calls close function or Ctrl-C was pressed
 484  *
 485  * Return: true if callback removed from the list, false otherwise
 486  */
 487 static bool mei_clear_lists(struct mei_device *dev, const struct file *file)
 488 {
 489         bool removed = false;
 490         struct mei_cl *cl = &dev->iamthif_cl;
 491
 492         /* remove callbacks associated with a file */
 493         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 494         if (mei_clear_list(dev, file, &cl->rd_completed))
 495                 removed = true;
 496
 497         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 498
 499         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 500                 removed = true;
 501
 502         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 503                 removed = true;
 504
 505         if (mei_clear_list(dev, file, &dev->write_list.list))
 506                 removed = true;
 507
 508         /* check if iamthif_current_cb not NULL */
 509         if (dev->iamthif_current_cb && !removed) {
 510                 /* check file and iamthif current cb association */
 511                 if (dev->iamthif_current_cb->fp == file) {
 512                         /* remove cb */
 513                         mei_io_cb_free(dev->iamthif_current_cb);
 514                         dev->iamthif_current_cb = NULL;
 515                         removed = true;
 516                 }
 517         }
 518         return removed;
 519 }
 520
 521 /**
 522 * mei_amthif_release - the release function
 523 *
 524 *  @dev: device structure
 525 *  @file: pointer to file structure
 526 *
 527 *  Return: 0 on success, <0 on error
 528 */
 529 int mei_amthif_release(struct mei_device *dev, struct file *file)
 530 {
 531         if (dev->iamthif_open_count > 0)
 532                 dev->iamthif_open_count--;
 533
 534         if (dev->iamthif_fp == file &&
 535             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 536
 537                 dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
 538                     dev->iamthif_state);
 539                 dev->iamthif_canceled = true;
 540                 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
 541                         dev_dbg(dev->dev, "run next amthif iamthif cb\n");
 542                         mei_amthif_run_next_cmd(dev);
 543                 }
 544         }
 545
 546         if (mei_clear_lists(dev, file))
 547                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 548
 549         return 0;
 550 }