drivers/firmware/dell_rbu.c

   1 /*
   2  * dell_rbu.c
   3  * Bios Update driver for Dell systems
   4  * Author: Dell Inc
   5  *         Abhay Salunke <abhay_salunke@dell.com>
   6  *
   7  * Copyright (C) 2005 Dell Inc.
   8  *
   9  * Remote BIOS Update (rbu) driver is used for updating DELL BIOS by
  10  * creating entries in the /sys file systems on Linux 2.6 and higher
  11  * kernels. The driver supports two mechanism to update the BIOS namely
  12  * contiguous and packetized. Both these methods still require having some
  13  * application to set the CMOS bit indicating the BIOS to update itself
  14  * after a reboot.
  15  *
  16  * Contiguous method:
  17  * This driver writes the incoming data in a monolithic image by allocating
  18  * contiguous physical pages large enough to accommodate the incoming BIOS
  19  * image size.
  20  *
  21  * Packetized method:
  22  * The driver writes the incoming packet image by allocating a new packet
  23  * on every time the packet data is written. This driver requires an
  24  * application to break the BIOS image in to fixed sized packet chunks.
  25  *
  26  * See Documentation/dell_rbu.txt for more info.
  27  *
  28  * This program is free software; you can redistribute it and/or modify
  29  * it under the terms of the GNU General Public License v2.0 as published by
  30  * the Free Software Foundation
  31  *
  32  * This program is distributed in the hope that it will be useful,
  33  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  34  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  35  * GNU General Public License for more details.
  36  */
  37 #include <linux/init.h>
  38 #include <linux/module.h>
  39 #include <linux/slab.h>
  40 #include <linux/string.h>
  41 #include <linux/errno.h>
  42 #include <linux/blkdev.h>
  43 #include <linux/platform_device.h>
  44 #include <linux/spinlock.h>
  45 #include <linux/moduleparam.h>
  46 #include <linux/firmware.h>
  47 #include <linux/dma-mapping.h>
  48
  49 MODULE_AUTHOR("Abhay Salunke <abhay_salunke@dell.com>");
  50 MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems");
  51 MODULE_LICENSE("GPL");
  52 MODULE_VERSION("3.2");
  53
  54 #define BIOS_SCAN_LIMIT 0xffffffff
  55 #define MAX_IMAGE_LENGTH 16
  56 static struct _rbu_data {
  57         void *image_update_buffer;
  58         unsigned long image_update_buffer_size;
  59         unsigned long bios_image_size;
  60         int image_update_ordernum;
  61         int dma_alloc;
  62         spinlock_t lock;
  63         unsigned long packet_read_count;
  64         unsigned long num_packets;
  65         unsigned long packetsize;
  66         unsigned long imagesize;
  67         int entry_created;
  68 } rbu_data;
  69
  70 static char image_type[MAX_IMAGE_LENGTH + 1] = "mono";
  71 module_param_string(image_type, image_type, sizeof (image_type), 0);
  72 MODULE_PARM_DESC(image_type,
  73         "BIOS image type. choose- mono or packet or init");
  74
  75 static unsigned long allocation_floor = 0x100000;
  76 module_param(allocation_floor, ulong, 0644);
  77 MODULE_PARM_DESC(allocation_floor,
  78     "Minimum address for allocations when using Packet mode");
  79
  80 struct packet_data {
  81         struct list_head list;
  82         size_t length;
  83         void *data;
  84         int ordernum;
  85 };
  86
  87 static struct packet_data packet_data_head;
  88
  89 static struct platform_device *rbu_device;
  90 static int context;
  91 static dma_addr_t dell_rbu_dmaaddr;
  92
  93 static void init_packet_head(void)
  94 {
  95         INIT_LIST_HEAD(&packet_data_head.list);
  96         rbu_data.packet_read_count = 0;
  97         rbu_data.num_packets = 0;
  98         rbu_data.packetsize = 0;
  99         rbu_data.imagesize = 0;
 100 }
 101
 102 static int create_packet(void *data, size_t length)
 103 {
 104         struct packet_data *newpacket;
 105         int ordernum = 0;
 106         int retval = 0;
 107         unsigned int packet_array_size = 0;
 108         void **invalid_addr_packet_array = NULL;
 109         void *packet_data_temp_buf = NULL;
 110         unsigned int idx = 0;
 111
 112         pr_debug("create_packet: entry \n");
 113
 114         if (!rbu_data.packetsize) {
 115                 pr_debug("create_packet: packetsize not specified\n");
 116                 retval = -EINVAL;
 117                 goto out_noalloc;
 118         }
 119
 120         spin_unlock(&rbu_data.lock);
 121
 122         newpacket = kzalloc(sizeof (struct packet_data), GFP_KERNEL);
 123
 124         if (!newpacket) {
 125                 printk(KERN_WARNING
 126                         "dell_rbu:%s: failed to allocate new "
 127                         "packet\n", __func__);
 128                 retval = -ENOMEM;
 129                 spin_lock(&rbu_data.lock);
 130                 goto out_noalloc;
 131         }
 132
 133         ordernum = get_order(length);
 134
 135         /*
 136          * BIOS errata mean we cannot allocate packets below 1MB or they will
 137          * be overwritten by BIOS.
 138          *
 139          * array to temporarily hold packets
 140          * that are below the allocation floor
 141          *
 142          * NOTE: very simplistic because we only need the floor to be at 1MB
 143          *       due to BIOS errata. This shouldn't be used for higher floors
 144          *       or you will run out of mem trying to allocate the array.
 145          */
 146         packet_array_size = max(
 147                         (unsigned int)(allocation_floor / rbu_data.packetsize),
 148                         (unsigned int)1);
 149         invalid_addr_packet_array = kzalloc(packet_array_size * sizeof(void*),
 150                                                 GFP_KERNEL);
 151
 152         if (!invalid_addr_packet_array) {
 153                 printk(KERN_WARNING
 154                         "dell_rbu:%s: failed to allocate "
 155                         "invalid_addr_packet_array \n",
 156                         __func__);
 157                 retval = -ENOMEM;
 158                 spin_lock(&rbu_data.lock);
 159                 goto out_alloc_packet;
 160         }
 161
 162         while (!packet_data_temp_buf) {
 163                 packet_data_temp_buf = (unsigned char *)
 164                         __get_free_pages(GFP_KERNEL, ordernum);
 165                 if (!packet_data_temp_buf) {
 166                         printk(KERN_WARNING
 167                                 "dell_rbu:%s: failed to allocate new "
 168                                 "packet\n", __func__);
 169                         retval = -ENOMEM;
 170                         spin_lock(&rbu_data.lock);
 171                         goto out_alloc_packet_array;
 172                 }
 173 #ifdef CONFIG_XEN
 174                 if (ordernum && xen_create_contiguous_region(
 175                         (unsigned long)packet_data_temp_buf, ordernum, 0)) {
 176                         free_pages((unsigned long)packet_data_temp_buf,
 177                                    ordernum);
 178                         pr_warning("dell_rbu:%s: failed to adjust new "
 179                                    "packet\n", __func__);
 180                         retval = -ENOMEM;
 181                         spin_lock(&rbu_data.lock);
 182                         goto out_alloc_packet_array;
 183                 }
 184 #endif
 185
 186                 if ((unsigned long)virt_to_bus(packet_data_temp_buf)
 187                                 < allocation_floor) {
 188 #ifdef CONFIG_XEN
 189                         if (ordernum)
 190                                 xen_destroy_contiguous_region(
 191                                         (unsigned long)packet_data_temp_buf,
 192                                         ordernum);
 193 #endif
 194                         pr_debug("packet 0x%lx below floor at 0x%lx.\n",
 195                                         (unsigned long)virt_to_phys(
 196                                                 packet_data_temp_buf),
 197                                         allocation_floor);
 198                         invalid_addr_packet_array[idx++] = packet_data_temp_buf;
 199                         packet_data_temp_buf = NULL;
 200                 }
 201         }
 202         spin_lock(&rbu_data.lock);
 203
 204         newpacket->data = packet_data_temp_buf;
 205
 206         pr_debug("create_packet: newpacket at physical addr %lx\n",
 207                 (unsigned long)virt_to_bus(newpacket->data));
 208
 209         /* packets may not have fixed size */
 210         newpacket->length = length;
 211         newpacket->ordernum = ordernum;
 212         ++rbu_data.num_packets;
 213
 214         /* initialize the newly created packet headers */
 215         INIT_LIST_HEAD(&newpacket->list);
 216         list_add_tail(&newpacket->list, &packet_data_head.list);
 217
 218         memcpy(newpacket->data, data, length);
 219
 220         pr_debug("create_packet: exit \n");
 221
 222 out_alloc_packet_array:
 223         /* always free packet array */
 224         for (;idx>0;idx--) {
 225                 pr_debug("freeing unused packet below floor 0x%lx.\n",
 226                         (unsigned long)virt_to_bus(
 227                                 invalid_addr_packet_array[idx-1]));
 228                 free_pages((unsigned long)invalid_addr_packet_array[idx-1],
 229                         ordernum);
 230         }
 231         kfree(invalid_addr_packet_array);
 232
 233 out_alloc_packet:
 234         /* if error, free data */
 235         if (retval)
 236                 kfree(newpacket);
 237
 238 out_noalloc:
 239         return retval;
 240 }
 241
 242 static int packetize_data(const u8 *data, size_t length)
 243 {
 244         int rc = 0;
 245         int done = 0;
 246         int packet_length;
 247         u8 *temp;
 248         u8 *end = (u8 *) data + length;
 249         pr_debug("packetize_data: data length %zd\n", length);
 250         if (!rbu_data.packetsize) {
 251                 printk(KERN_WARNING
 252                         "dell_rbu: packetsize not specified\n");
 253                 return -EIO;
 254         }
 255
 256         temp = (u8 *) data;
 257
 258         /* packetize the hunk */
 259         while (!done) {
 260                 if ((temp + rbu_data.packetsize) < end)
 261                         packet_length = rbu_data.packetsize;
 262                 else {
 263                         /* this is the last packet */
 264                         packet_length = end - temp;
 265                         done = 1;
 266                 }
 267
 268                 if ((rc = create_packet(temp, packet_length)))
 269                         return rc;
 270
 271                 pr_debug("%p:%td\n", temp, (end - temp));
 272                 temp += packet_length;
 273         }
 274
 275         rbu_data.imagesize = length;
 276
 277         return rc;
 278 }
 279
 280 static int do_packet_read(char *data, struct list_head *ptemp_list,
 281         int length, int bytes_read, int *list_read_count)
 282 {
 283         void *ptemp_buf;
 284         struct packet_data *newpacket = NULL;
 285         int bytes_copied = 0;
 286         int j = 0;
 287
 288         newpacket = list_entry(ptemp_list, struct packet_data, list);
 289         *list_read_count += newpacket->length;
 290
 291         if (*list_read_count > bytes_read) {
 292                 /* point to the start of unread data */
 293                 j = newpacket->length - (*list_read_count - bytes_read);
 294                 /* point to the offset in the packet buffer */
 295                 ptemp_buf = (u8 *) newpacket->data + j;
 296                 /*
 297                  * check if there is enough room in
 298                  * * the incoming buffer
 299                  */
 300                 if (length > (*list_read_count - bytes_read))
 301                         /*
 302                          * copy what ever is there in this
 303                          * packet and move on
 304                          */
 305                         bytes_copied = (*list_read_count - bytes_read);
 306                 else
 307                         /* copy the remaining */
 308                         bytes_copied = length;
 309                 memcpy(data, ptemp_buf, bytes_copied);
 310         }
 311         return bytes_copied;
 312 }
 313
 314 static int packet_read_list(char *data, size_t * pread_length)
 315 {
 316         struct list_head *ptemp_list;
 317         int temp_count = 0;
 318         int bytes_copied = 0;
 319         int bytes_read = 0;
 320         int remaining_bytes = 0;
 321         char *pdest = data;
 322
 323         /* check if we have any packets */
 324         if (0 == rbu_data.num_packets)
 325                 return -ENOMEM;
 326
 327         remaining_bytes = *pread_length;
 328         bytes_read = rbu_data.packet_read_count;
 329
 330         ptemp_list = (&packet_data_head.list)->next;
 331         while (!list_empty(ptemp_list)) {
 332                 bytes_copied = do_packet_read(pdest, ptemp_list,
 333                         remaining_bytes, bytes_read, &temp_count);
 334                 remaining_bytes -= bytes_copied;
 335                 bytes_read += bytes_copied;
 336                 pdest += bytes_copied;
 337                 /*
 338                  * check if we reached end of buffer before reaching the
 339                  * last packet
 340                  */
 341                 if (remaining_bytes == 0)
 342                         break;
 343
 344                 ptemp_list = ptemp_list->next;
 345         }
 346         /*finally set the bytes read */
 347         *pread_length = bytes_read - rbu_data.packet_read_count;
 348         rbu_data.packet_read_count = bytes_read;
 349         return 0;
 350 }
 351
 352 static void packet_empty_list(void)
 353 {
 354         struct list_head *ptemp_list;
 355         struct list_head *pnext_list;
 356         struct packet_data *newpacket;
 357
 358         ptemp_list = (&packet_data_head.list)->next;
 359         while (!list_empty(ptemp_list)) {
 360                 newpacket =
 361                         list_entry(ptemp_list, struct packet_data, list);
 362                 pnext_list = ptemp_list->next;
 363                 list_del(ptemp_list);
 364                 ptemp_list = pnext_list;
 365                 /*
 366                  * zero out the RBU packet memory before freeing
 367                  * to make sure there are no stale RBU packets left in memory
 368                  */
 369                 memset(newpacket->data, 0, rbu_data.packetsize);
 370 #ifdef CONFIG_XEN
 371                 if (newpacket->ordernum)
 372                         xen_destroy_contiguous_region(
 373                                 (unsigned long)newpacket->data,
 374                                 newpacket->ordernum);
 375 #endif
 376
 377                 free_pages((unsigned long) newpacket->data,
 378                         newpacket->ordernum);
 379                 kfree(newpacket);
 380         }
 381         rbu_data.packet_read_count = 0;
 382         rbu_data.num_packets = 0;
 383         rbu_data.imagesize = 0;
 384 }
 385
 386 /*
 387  * img_update_free: Frees the buffer allocated for storing BIOS image
 388  * Always called with lock held and returned with lock held
 389  */
 390 static void img_update_free(void)
 391 {
 392         if (!rbu_data.image_update_buffer)
 393                 return;
 394         /*
 395          * zero out this buffer before freeing it to get rid of any stale
 396          * BIOS image copied in memory.
 397          */
 398         memset(rbu_data.image_update_buffer, 0,
 399                 rbu_data.image_update_buffer_size);
 400         if (rbu_data.dma_alloc == 1)
 401                 dma_free_coherent(NULL, rbu_data.bios_image_size,
 402                         rbu_data.image_update_buffer, dell_rbu_dmaaddr);
 403         else
 404                 free_pages((unsigned long) rbu_data.image_update_buffer,
 405                         rbu_data.image_update_ordernum);
 406
 407         /*
 408          * Re-initialize the rbu_data variables after a free
 409          */
 410         rbu_data.image_update_ordernum = -1;
 411         rbu_data.image_update_buffer = NULL;
 412         rbu_data.image_update_buffer_size = 0;
 413         rbu_data.bios_image_size = 0;
 414         rbu_data.dma_alloc = 0;
 415 }
 416
 417 /*
 418  * img_update_realloc: This function allocates the contiguous pages to
 419  * accommodate the requested size of data. The memory address and size
 420  * values are stored globally and on every call to this function the new
 421  * size is checked to see if more data is required than the existing size.
 422  * If true the previous memory is freed and new allocation is done to
 423  * accommodate the new size. If the incoming size is less then than the
 424  * already allocated size, then that memory is reused. This function is
 425  * called with lock held and returns with lock held.
 426  */
 427 static int img_update_realloc(unsigned long size)
 428 {
 429         unsigned char *image_update_buffer = NULL;
 430         unsigned long rc;
 431 #ifndef CONFIG_XEN
 432         unsigned long img_buf_phys_addr;
 433 #endif
 434         int ordernum;
 435         int dma_alloc = 0;
 436
 437         /*
 438          * check if the buffer of sufficient size has been
 439          * already allocated
 440          */
 441         if (rbu_data.image_update_buffer_size >= size) {
 442                 /*
 443                  * check for corruption
 444                  */
 445                 if ((size != 0) && (rbu_data.image_update_buffer == NULL)) {
 446                         printk(KERN_ERR "dell_rbu:%s: corruption "
 447                                 "check failed\n", __func__);
 448                         return -EINVAL;
 449                 }
 450                 /*
 451                  * we have a valid pre-allocated buffer with
 452                  * sufficient size
 453                  */
 454                 return 0;
 455         }
 456
 457         /*
 458          * free any previously allocated buffer
 459          */
 460         img_update_free();
 461
 462         spin_unlock(&rbu_data.lock);
 463
 464 #ifndef CONFIG_XEN
 465         ordernum = get_order(size);
 466         image_update_buffer =
 467                 (unsigned char *) __get_free_pages(GFP_KERNEL, ordernum);
 468
 469         img_buf_phys_addr =
 470                 (unsigned long) virt_to_bus(image_update_buffer);
 471
 472         if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
 473                 free_pages((unsigned long) image_update_buffer, ordernum);
 474 #else
 475         {
 476 #endif
 477                 ordernum = -1;
 478                 image_update_buffer = dma_alloc_coherent(NULL, size,
 479                         &dell_rbu_dmaaddr, GFP_KERNEL);
 480                 dma_alloc = 1;
 481         }
 482
 483         spin_lock(&rbu_data.lock);
 484
 485         if (image_update_buffer != NULL) {
 486                 rbu_data.image_update_buffer = image_update_buffer;
 487                 rbu_data.image_update_buffer_size = size;
 488                 rbu_data.bios_image_size =
 489                         rbu_data.image_update_buffer_size;
 490                 rbu_data.image_update_ordernum = ordernum;
 491                 rbu_data.dma_alloc = dma_alloc;
 492                 rc = 0;
 493         } else {
 494                 pr_debug("Not enough memory for image update:"
 495                         "size = %ld\n", size);
 496                 rc = -ENOMEM;
 497         }
 498
 499         return rc;
 500 }
 501
 502 static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
 503 {
 504         int retval;
 505         size_t bytes_left;
 506         size_t data_length;
 507         char *ptempBuf = buffer;
 508
 509         /* check to see if we have something to return */
 510         if (rbu_data.num_packets == 0) {
 511                 pr_debug("read_packet_data: no packets written\n");
 512                 retval = -ENOMEM;
 513                 goto read_rbu_data_exit;
 514         }
 515
 516         if (pos > rbu_data.imagesize) {
 517                 retval = 0;
 518                 printk(KERN_WARNING "dell_rbu:read_packet_data: "
 519                         "data underrun\n");
 520                 goto read_rbu_data_exit;
 521         }
 522
 523         bytes_left = rbu_data.imagesize - pos;
 524         data_length = min(bytes_left, count);
 525
 526         if ((retval = packet_read_list(ptempBuf, &data_length)) < 0)
 527                 goto read_rbu_data_exit;
 528
 529         if ((pos + count) > rbu_data.imagesize) {
 530                 rbu_data.packet_read_count = 0;
 531                 /* this was the last copy */
 532                 retval = bytes_left;
 533         } else
 534                 retval = count;
 535
 536       read_rbu_data_exit:
 537         return retval;
 538 }
 539
 540 static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
 541 {
 542         /* check to see if we have something to return */
 543         if ((rbu_data.image_update_buffer == NULL) ||
 544                 (rbu_data.bios_image_size == 0)) {
 545                 pr_debug("read_rbu_data_mono: image_update_buffer %p ,"
 546                         "bios_image_size %lu\n",
 547                         rbu_data.image_update_buffer,
 548                         rbu_data.bios_image_size);
 549                 return -ENOMEM;
 550         }
 551
 552         return memory_read_from_buffer(buffer, count, &pos,
 553                         rbu_data.image_update_buffer, rbu_data.bios_image_size);
 554 }
 555
 556 static ssize_t read_rbu_data(struct file *filp, struct kobject *kobj,
 557                              struct bin_attribute *bin_attr,
 558                              char *buffer, loff_t pos, size_t count)
 559 {
 560         ssize_t ret_count = 0;
 561
 562         spin_lock(&rbu_data.lock);
 563
 564         if (!strcmp(image_type, "mono"))
 565                 ret_count = read_rbu_mono_data(buffer, pos, count);
 566         else if (!strcmp(image_type, "packet"))
 567                 ret_count = read_packet_data(buffer, pos, count);
 568         else
 569                 pr_debug("read_rbu_data: invalid image type specified\n");
 570
 571         spin_unlock(&rbu_data.lock);
 572         return ret_count;
 573 }
 574
 575 static void callbackfn_rbu(const struct firmware *fw, void *context)
 576 {
 577         rbu_data.entry_created = 0;
 578
 579         if (!fw)
 580                 return;
 581
 582         if (!fw->size)
 583                 goto out;
 584
 585         spin_lock(&rbu_data.lock);
 586         if (!strcmp(image_type, "mono")) {
 587                 if (!img_update_realloc(fw->size))
 588                         memcpy(rbu_data.image_update_buffer,
 589                                 fw->data, fw->size);
 590         } else if (!strcmp(image_type, "packet")) {
 591                 /*
 592                  * we need to free previous packets if a
 593                  * new hunk of packets needs to be downloaded
 594                  */
 595                 packet_empty_list();
 596                 if (packetize_data(fw->data, fw->size))
 597                         /* Incase something goes wrong when we are
 598                          * in middle of packetizing the data, we
 599                          * need to free up whatever packets might
 600                          * have been created before we quit.
 601                          */
 602                         packet_empty_list();
 603         } else
 604                 pr_debug("invalid image type specified.\n");
 605         spin_unlock(&rbu_data.lock);
 606  out:
 607         release_firmware(fw);
 608 }
 609
 610 static ssize_t read_rbu_image_type(struct file *filp, struct kobject *kobj,
 611                                    struct bin_attribute *bin_attr,
 612                                    char *buffer, loff_t pos, size_t count)
 613 {
 614         int size = 0;
 615         if (!pos)
 616                 size = scnprintf(buffer, count, "%s\n", image_type);
 617         return size;
 618 }
 619
 620 static ssize_t write_rbu_image_type(struct file *filp, struct kobject *kobj,
 621                                     struct bin_attribute *bin_attr,
 622                                     char *buffer, loff_t pos, size_t count)
 623 {
 624         int rc = count;
 625         int req_firm_rc = 0;
 626         int i;
 627         spin_lock(&rbu_data.lock);
 628         /*
 629          * Find the first newline or space
 630          */
 631         for (i = 0; i < count; ++i)
 632                 if (buffer[i] == '\n' || buffer[i] == ' ') {
 633                         buffer[i] = '\0';
 634                         break;
 635                 }
 636         if (i == count)
 637                 buffer[count] = '\0';
 638
 639         if (strstr(buffer, "mono"))
 640                 strcpy(image_type, "mono");
 641         else if (strstr(buffer, "packet"))
 642                 strcpy(image_type, "packet");
 643         else if (strstr(buffer, "init")) {
 644                 /*
 645                  * If due to the user error the driver gets in a bad
 646                  * state where even though it is loaded , the
 647                  * /sys/class/firmware/dell_rbu entries are missing.
 648                  * to cover this situation the user can recreate entries
 649                  * by writing init to image_type.
 650                  */
 651                 if (!rbu_data.entry_created) {
 652                         spin_unlock(&rbu_data.lock);
 653                         req_firm_rc = request_firmware_nowait(THIS_MODULE,
 654                                 FW_ACTION_NOHOTPLUG, "dell_rbu",
 655                                 &rbu_device->dev, GFP_KERNEL, &context,
 656                                 callbackfn_rbu);
 657                         if (req_firm_rc) {
 658                                 printk(KERN_ERR
 659                                         "dell_rbu:%s request_firmware_nowait"
 660                                         " failed %d\n", __func__, rc);
 661                                 rc = -EIO;
 662                         } else
 663                                 rbu_data.entry_created = 1;
 664
 665                         spin_lock(&rbu_data.lock);
 666                 }
 667         } else {
 668                 printk(KERN_WARNING "dell_rbu: image_type is invalid\n");
 669                 spin_unlock(&rbu_data.lock);
 670                 return -EINVAL;
 671         }
 672
 673         /* we must free all previous allocations */
 674         packet_empty_list();
 675         img_update_free();
 676         spin_unlock(&rbu_data.lock);
 677
 678         return rc;
 679 }
 680
 681 static ssize_t read_rbu_packet_size(struct file *filp, struct kobject *kobj,
 682                                     struct bin_attribute *bin_attr,
 683                                     char *buffer, loff_t pos, size_t count)
 684 {
 685         int size = 0;
 686         if (!pos) {
 687                 spin_lock(&rbu_data.lock);
 688                 size = scnprintf(buffer, count, "%lu\n", rbu_data.packetsize);
 689                 spin_unlock(&rbu_data.lock);
 690         }
 691         return size;
 692 }
 693
 694 static ssize_t write_rbu_packet_size(struct file *filp, struct kobject *kobj,
 695                                      struct bin_attribute *bin_attr,
 696                                      char *buffer, loff_t pos, size_t count)
 697 {
 698         unsigned long temp;
 699         spin_lock(&rbu_data.lock);
 700         packet_empty_list();
 701         sscanf(buffer, "%lu", &temp);
 702         if (temp < 0xffffffff)
 703                 rbu_data.packetsize = temp;
 704
 705         spin_unlock(&rbu_data.lock);
 706         return count;
 707 }
 708
 709 static struct bin_attribute rbu_data_attr = {
 710         .attr = {.name = "data", .mode = 0444},
 711         .read = read_rbu_data,
 712 };
 713
 714 static struct bin_attribute rbu_image_type_attr = {
 715         .attr = {.name = "image_type", .mode = 0644},
 716         .read = read_rbu_image_type,
 717         .write = write_rbu_image_type,
 718 };
 719
 720 static struct bin_attribute rbu_packet_size_attr = {
 721         .attr = {.name = "packet_size", .mode = 0644},
 722         .read = read_rbu_packet_size,
 723         .write = write_rbu_packet_size,
 724 };
 725
 726 static int __init dcdrbu_init(void)
 727 {
 728         int rc;
 729
 730 #ifdef CONFIG_XEN
 731         if (!is_initial_xendomain())
 732                 return -ENODEV;
 733 #endif
 734
 735         spin_lock_init(&rbu_data.lock);
 736
 737         init_packet_head();
 738         rbu_device = platform_device_register_simple("dell_rbu", -1, NULL, 0);
 739         if (IS_ERR(rbu_device)) {
 740                 printk(KERN_ERR
 741                         "dell_rbu:%s:platform_device_register_simple "
 742                         "failed\n", __func__);
 743                 return PTR_ERR(rbu_device);
 744         }
 745
 746         rc = sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
 747         if (rc)
 748                 goto out_devreg;
 749         rc = sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
 750         if (rc)
 751                 goto out_data;
 752         rc = sysfs_create_bin_file(&rbu_device->dev.kobj,
 753                 &rbu_packet_size_attr);
 754         if (rc)
 755                 goto out_imtype;
 756
 757         rbu_data.entry_created = 0;
 758         return 0;
 759
 760 out_imtype:
 761         sysfs_remove_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
 762 out_data:
 763         sysfs_remove_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
 764 out_devreg:
 765         platform_device_unregister(rbu_device);
 766         return rc;
 767 }
 768
 769 static __exit void dcdrbu_exit(void)
 770 {
 771         spin_lock(&rbu_data.lock);
 772         packet_empty_list();
 773         img_update_free();
 774         spin_unlock(&rbu_data.lock);
 775         platform_device_unregister(rbu_device);
 776 }
 777
 778 module_exit(dcdrbu_exit);
 779 module_init(dcdrbu_init);
 780
 781 /* vim:noet:ts=8:sw=8
 782 */