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                 return 0;
 304
 305         return mei_amthif_run_next_cmd(dev);
 306 }
 307
 308 /**
 309  * mei_amthif_poll - the amthif poll function
 310  *
 311  * @file: pointer to file structure
 312  * @wait: pointer to poll_table structure
 313  *
 314  * Return: poll mask
 315  *
 316  * Locking: called under "dev->device_lock" lock
 317  */
 318 unsigned int mei_amthif_poll(struct file *file, poll_table *wait)
 319 {
 320         struct mei_cl *cl = file->private_data;
 321         struct mei_cl_cb *cb = mei_cl_read_cb(cl, file);
 322         unsigned int mask = 0;
 323
 324         poll_wait(file, &cl->rx_wait, wait);
 325         if (cb)
 326                 mask |= POLLIN | POLLRDNORM;
 327
 328         return mask;
 329 }
 330
 331 /**
 332  * mei_amthif_irq_write - write iamthif command in irq thread context.
 333  *
 334  * @cl: private data of the file object.
 335  * @cb: callback block.
 336  * @cmpl_list: complete list.
 337  *
 338  * Return: 0, OK; otherwise, error.
 339  */
 340 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 341                          struct mei_cl_cb *cmpl_list)
 342 {
 343         int ret;
 344
 345         ret = mei_cl_irq_write(cl, cb, cmpl_list);
 346         if (ret)
 347                 return ret;
 348
 349         if (cb->completed)
 350                 cb->status = mei_amthif_read_start(cl, cb->fp);
 351
 352         return 0;
 353 }
 354
 355 /**
 356  * mei_amthif_irq_read_msg - read routine after ISR to
 357  *                      handle the read amthif message
 358  *
 359  * @cl: mei client
 360  * @mei_hdr: header of amthif message
 361  * @cmpl_list: completed callbacks list
 362  *
 363  * Return: -ENODEV if cb is NULL 0 otherwise; error message is in cb->status
 364  */
 365 int mei_amthif_irq_read_msg(struct mei_cl *cl,
 366                             struct mei_msg_hdr *mei_hdr,
 367                             struct mei_cl_cb *cmpl_list)
 368 {
 369         struct mei_device *dev;
 370         int ret;
 371
 372         dev = cl->dev;
 373
 374         if (dev->iamthif_state != MEI_IAMTHIF_READING) {
 375                 mei_irq_discard_msg(dev, mei_hdr);
 376                 return 0;
 377         }
 378
 379         ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 380         if (ret)
 381                 return ret;
 382
 383         if (!mei_hdr->msg_complete)
 384                 return 0;
 385
 386         dev_dbg(dev->dev, "completed amthif read.\n ");
 387         dev->iamthif_stall_timer = 0;
 388
 389         return 0;
 390 }
 391
 392 /**
 393  * mei_amthif_complete - complete amthif callback.
 394  *
 395  * @cl: host client
 396  * @cb: callback block.
 397  */
 398 void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 399 {
 400         struct mei_device *dev = cl->dev;
 401
 402         if (cb->fop_type == MEI_FOP_WRITE) {
 403                 if (!cb->status) {
 404                         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 405                         mei_io_cb_free(cb);
 406                         return;
 407                 }
 408                 /*
 409                  * in case of error enqueue the write cb to complete read list
 410                  * so it can be propagated to the reader
 411                  */
 412                 list_add_tail(&cb->list, &cl->rd_completed);
 413                 wake_up_interruptible(&cl->rx_wait);
 414                 return;
 415         }
 416
 417         if (!dev->iamthif_canceled) {
 418                 list_add_tail(&cb->list, &cl->rd_completed);
 419                 dev_dbg(dev->dev, "amthif read completed\n");
 420         } else {
 421                 mei_io_cb_free(cb);
 422         }
 423
 424         dev->iamthif_current_cb = NULL;
 425         dev->iamthif_stall_timer = 0;
 426         mei_amthif_run_next_cmd(dev);
 427
 428         dev_dbg(dev->dev, "completing amthif call back.\n");
 429         wake_up_interruptible(&cl->rx_wait);
 430 }
 431
 432 /**
 433  * mei_clear_list - removes all callbacks associated with file
 434  *              from mei_cb_list
 435  *
 436  * @dev: device structure.
 437  * @file: file structure
 438  * @mei_cb_list: callbacks list
 439  *
 440  * mei_clear_list is called to clear resources associated with file
 441  * when application calls close function or Ctrl-C was pressed
 442  *
 443  * Return: true if callback removed from the list, false otherwise
 444  */
 445 static bool mei_clear_list(struct mei_device *dev,
 446                 const struct file *file, struct list_head *mei_cb_list)
 447 {
 448         struct mei_cl *cl = &dev->iamthif_cl;
 449         struct mei_cl_cb *cb, *next;
 450         bool removed = false;
 451
 452         /* list all list member */
 453         list_for_each_entry_safe(cb, next, mei_cb_list, list) {
 454                 /* check if list member associated with a file */
 455                 if (file == cb->fp) {
 456                         /* check if cb equal to current iamthif cb */
 457                         if (dev->iamthif_current_cb == cb) {
 458                                 dev->iamthif_current_cb = NULL;
 459                                 /* send flow control to iamthif client */
 460                                 mei_hbm_cl_flow_control_req(dev, cl);
 461                         }
 462                         /* free all allocated buffers */
 463                         mei_io_cb_free(cb);
 464                         removed = true;
 465                 }
 466         }
 467         return removed;
 468 }
 469
 470 /**
 471  * mei_clear_lists - removes all callbacks associated with file
 472  *
 473  * @dev: device structure
 474  * @file: file structure
 475  *
 476  * mei_clear_lists is called to clear resources associated with file
 477  * when application calls close function or Ctrl-C was pressed
 478  *
 479  * Return: true if callback removed from the list, false otherwise
 480  */
 481 static bool mei_clear_lists(struct mei_device *dev, const struct file *file)
 482 {
 483         bool removed = false;
 484         struct mei_cl *cl = &dev->iamthif_cl;
 485
 486         /* remove callbacks associated with a file */
 487         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 488         if (mei_clear_list(dev, file, &cl->rd_completed))
 489                 removed = true;
 490
 491         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 492
 493         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 494                 removed = true;
 495
 496         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 497                 removed = true;
 498
 499         if (mei_clear_list(dev, file, &dev->write_list.list))
 500                 removed = true;
 501
 502         /* check if iamthif_current_cb not NULL */
 503         if (dev->iamthif_current_cb && !removed) {
 504                 /* check file and iamthif current cb association */
 505                 if (dev->iamthif_current_cb->fp == file) {
 506                         /* remove cb */
 507                         mei_io_cb_free(dev->iamthif_current_cb);
 508                         dev->iamthif_current_cb = NULL;
 509                         removed = true;
 510                 }
 511         }
 512         return removed;
 513 }
 514
 515 /**
 516 * mei_amthif_release - the release function
 517 *
 518 *  @dev: device structure
 519 *  @file: pointer to file structure
 520 *
 521 *  Return: 0 on success, <0 on error
 522 */
 523 int mei_amthif_release(struct mei_device *dev, struct file *file)
 524 {
 525         if (dev->iamthif_open_count > 0)
 526                 dev->iamthif_open_count--;
 527
 528         if (dev->iamthif_fp == file &&
 529             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 530
 531                 dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
 532                     dev->iamthif_state);
 533                 dev->iamthif_canceled = true;
 534         }
 535
 536         if (mei_clear_lists(dev, file))
 537                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 538
 539         return 0;
 540 }