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_canceled = false;
  51         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  52         dev->iamthif_stall_timer = 0;
  53         dev->iamthif_open_count = 0;
  54 }
  55
  56 /**
  57  * mei_amthif_host_init - mei initialization amthif client.
  58  *
  59  * @dev: the device structure
  60  * @me_cl: me client
  61  *
  62  * Return: 0 on success, <0 on failure.
  63  */
  64 int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
  65 {
  66         struct mei_cl *cl = &dev->iamthif_cl;
  67         int ret;
  68
  69         mutex_lock(&dev->device_lock);
  70
  71         if (mei_cl_is_connected(cl)) {
  72                 ret = 0;
  73                 goto out;
  74         }
  75
  76         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  77
  78         mei_cl_init(cl, dev);
  79
  80         ret = mei_cl_link(cl);
  81         if (ret < 0) {
  82                 dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
  83                 goto out;
  84         }
  85
  86         ret = mei_cl_connect(cl, me_cl, NULL);
  87
  88 out:
  89         mutex_unlock(&dev->device_lock);
  90         return ret;
  91 }
  92
  93 /**
  94  * mei_amthif_read_start - queue message for sending read credential
  95  *
  96  * @cl: host client
  97  * @fp: file pointer of message recipient
  98  *
  99  * Return: 0 on success, <0 on failure.
 100  */
 101 static int mei_amthif_read_start(struct mei_cl *cl, const struct file *fp)
 102 {
 103         struct mei_device *dev = cl->dev;
 104         struct mei_cl_cb *cb;
 105
 106         cb = mei_cl_enqueue_ctrl_wr_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, fp);
 107         if (!cb)
 108                 return -ENOMEM;
 109
 110         cl->rx_flow_ctrl_creds++;
 111
 112         dev->iamthif_state = MEI_IAMTHIF_READING;
 113         cl->fp = cb->fp;
 114
 115         return 0;
 116 }
 117
 118 /**
 119  * mei_amthif_run_next_cmd - send next amt command from queue
 120  *
 121  * @dev: the device structure
 122  *
 123  * Return: 0 on success, <0 on failure.
 124  */
 125 int mei_amthif_run_next_cmd(struct mei_device *dev)
 126 {
 127         struct mei_cl *cl = &dev->iamthif_cl;
 128         struct mei_cl_cb *cb;
 129         int ret;
 130
 131         dev->iamthif_canceled = false;
 132
 133         dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
 134
 135         cb = list_first_entry_or_null(&dev->amthif_cmd_list.list,
 136                                         typeof(*cb), list);
 137         if (!cb) {
 138                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 139                 cl->fp = NULL;
 140                 return 0;
 141         }
 142
 143         list_del_init(&cb->list);
 144         dev->iamthif_state = MEI_IAMTHIF_WRITING;
 145         cl->fp = cb->fp;
 146
 147         ret = mei_cl_write(cl, cb, false);
 148         if (ret < 0)
 149                 return ret;
 150
 151         if (cb->completed)
 152                 cb->status = mei_amthif_read_start(cl, cb->fp);
 153
 154         return 0;
 155 }
 156
 157 /**
 158  * mei_amthif_write - write amthif data to amthif client
 159  *
 160  * @cl: host client
 161  * @cb: mei call back struct
 162  *
 163  * Return: 0 on success, <0 on failure.
 164  */
 165 int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 166 {
 167
 168         struct mei_device *dev = cl->dev;
 169
 170         list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
 171
 172         /*
 173          * The previous request is still in processing, queue this one.
 174          */
 175         if (dev->iamthif_state != MEI_IAMTHIF_IDLE)
 176                 return 0;
 177
 178         return mei_amthif_run_next_cmd(dev);
 179 }
 180
 181 /**
 182  * mei_amthif_poll - the amthif poll function
 183  *
 184  * @file: pointer to file structure
 185  * @wait: pointer to poll_table structure
 186  *
 187  * Return: poll mask
 188  *
 189  * Locking: called under "dev->device_lock" lock
 190  */
 191 unsigned int mei_amthif_poll(struct file *file, poll_table *wait)
 192 {
 193         struct mei_cl *cl = file->private_data;
 194         struct mei_cl_cb *cb = mei_cl_read_cb(cl, file);
 195         unsigned int mask = 0;
 196
 197         poll_wait(file, &cl->rx_wait, wait);
 198         if (cb)
 199                 mask |= POLLIN | POLLRDNORM;
 200
 201         return mask;
 202 }
 203
 204 /**
 205  * mei_amthif_irq_write - write iamthif command in irq thread context.
 206  *
 207  * @cl: private data of the file object.
 208  * @cb: callback block.
 209  * @cmpl_list: complete list.
 210  *
 211  * Return: 0, OK; otherwise, error.
 212  */
 213 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 214                          struct mei_cl_cb *cmpl_list)
 215 {
 216         int ret;
 217
 218         ret = mei_cl_irq_write(cl, cb, cmpl_list);
 219         if (ret)
 220                 return ret;
 221
 222         if (cb->completed)
 223                 cb->status = mei_amthif_read_start(cl, cb->fp);
 224
 225         return 0;
 226 }
 227
 228 /**
 229  * mei_amthif_irq_read_msg - read routine after ISR to
 230  *                      handle the read amthif message
 231  *
 232  * @cl: mei client
 233  * @mei_hdr: header of amthif message
 234  * @cmpl_list: completed callbacks list
 235  *
 236  * Return: -ENODEV if cb is NULL 0 otherwise; error message is in cb->status
 237  */
 238 int mei_amthif_irq_read_msg(struct mei_cl *cl,
 239                             struct mei_msg_hdr *mei_hdr,
 240                             struct mei_cl_cb *cmpl_list)
 241 {
 242         struct mei_device *dev;
 243         int ret;
 244
 245         dev = cl->dev;
 246
 247         if (dev->iamthif_state != MEI_IAMTHIF_READING) {
 248                 mei_irq_discard_msg(dev, mei_hdr);
 249                 return 0;
 250         }
 251
 252         ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
 253         if (ret)
 254                 return ret;
 255
 256         if (!mei_hdr->msg_complete)
 257                 return 0;
 258
 259         dev_dbg(dev->dev, "completed amthif read.\n ");
 260         dev->iamthif_stall_timer = 0;
 261
 262         return 0;
 263 }
 264
 265 /**
 266  * mei_amthif_complete - complete amthif callback.
 267  *
 268  * @cl: host client
 269  * @cb: callback block.
 270  */
 271 void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 272 {
 273         struct mei_device *dev = cl->dev;
 274
 275         dev_dbg(dev->dev, "completing amthif call back.\n");
 276         switch (cb->fop_type) {
 277         case MEI_FOP_WRITE:
 278                 if (!cb->status) {
 279                         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 280                         mei_schedule_stall_timer(dev);
 281                         mei_io_cb_free(cb);
 282                         return;
 283                 }
 284                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 285                 cl->fp = NULL;
 286                 if (!dev->iamthif_canceled) {
 287                         /*
 288                          * in case of error enqueue the write cb to complete
 289                          * read list so it can be propagated to the reader
 290                          */
 291                         list_add_tail(&cb->list, &cl->rd_completed);
 292                         wake_up_interruptible(&cl->rx_wait);
 293                 } else {
 294                         mei_io_cb_free(cb);
 295                 }
 296                 break;
 297         case MEI_FOP_READ:
 298                 if (!dev->iamthif_canceled) {
 299                         list_add_tail(&cb->list, &cl->rd_completed);
 300                         dev_dbg(dev->dev, "amthif read completed\n");
 301                         wake_up_interruptible(&cl->rx_wait);
 302                 } else {
 303                         mei_io_cb_free(cb);
 304                 }
 305
 306                 dev->iamthif_stall_timer = 0;
 307                 mei_amthif_run_next_cmd(dev);
 308                 break;
 309         default:
 310                 WARN_ON(1);
 311         }
 312 }
 313
 314 /**
 315  * mei_clear_list - removes all callbacks associated with file
 316  *              from mei_cb_list
 317  *
 318  * @file: file structure
 319  * @mei_cb_list: callbacks list
 320  *
 321  * mei_clear_list is called to clear resources associated with file
 322  * when application calls close function or Ctrl-C was pressed
 323  */
 324 static void mei_clear_list(const struct file *file,
 325                            struct list_head *mei_cb_list)
 326 {
 327         struct mei_cl_cb *cb, *next;
 328
 329         list_for_each_entry_safe(cb, next, mei_cb_list, list)
 330                 if (file == cb->fp)
 331                         mei_io_cb_free(cb);
 332 }
 333
 334 /**
 335 * mei_amthif_release - the release function
 336 *
 337 *  @dev: device structure
 338 *  @file: pointer to file structure
 339 *
 340 *  Return: 0 on success, <0 on error
 341 */
 342 int mei_amthif_release(struct mei_device *dev, struct file *file)
 343 {
 344         struct mei_cl *cl = file->private_data;
 345
 346         if (dev->iamthif_open_count > 0)
 347                 dev->iamthif_open_count--;
 348
 349         if (cl->fp == file && dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 350
 351                 dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
 352                     dev->iamthif_state);
 353                 dev->iamthif_canceled = true;
 354         }
 355
 356         mei_clear_list(file, &dev->amthif_cmd_list.list);
 357         mei_clear_list(file, &cl->rd_completed);
 358         mei_clear_list(file, &dev->ctrl_rd_list.list);
 359
 360         return 0;
 361 }