drivers/char/ps3flash.c

   1 /*
   2  * PS3 FLASH ROM Storage Driver
   3  *
   4  * Copyright (C) 2007 Sony Computer Entertainment Inc.
   5  * Copyright 2007 Sony Corp.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation; version 2 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <linux/fs.h>
  22 #include <linux/miscdevice.h>
  23 #include <linux/uaccess.h>
  24
  25 #include <asm/lv1call.h>
  26 #include <asm/ps3stor.h>
  27
  28
  29 #define DEVICE_NAME             "ps3flash"
  30
  31 #define FLASH_BLOCK_SIZE        (256*1024)
  32
  33
  34 struct ps3flash_private {
  35         struct mutex mutex;     /* Bounce buffer mutex */
  36 };
  37
  38 static struct ps3_storage_device *ps3flash_dev;
  39
  40 static ssize_t ps3flash_read_write_sectors(struct ps3_storage_device *dev,
  41                                            u64 lpar, u64 start_sector,
  42                                            u64 sectors, int write)
  43 {
  44         u64 res = ps3stor_read_write_sectors(dev, lpar, start_sector, sectors,
  45                                              write);
  46         if (res) {
  47                 dev_err(&dev->sbd.core, "%s:%u: %s failed 0x%llx\n", __func__,
  48                         __LINE__, write ? "write" : "read", res);
  49                 return -EIO;
  50         }
  51         return sectors;
  52 }
  53
  54 static ssize_t ps3flash_read_sectors(struct ps3_storage_device *dev,
  55                                      u64 start_sector, u64 sectors,
  56                                      unsigned int sector_offset)
  57 {
  58         u64 max_sectors, lpar;
  59
  60         max_sectors = dev->bounce_size / dev->blk_size;
  61         if (sectors > max_sectors) {
  62                 dev_dbg(&dev->sbd.core, "%s:%u Limiting sectors to %llu\n",
  63                         __func__, __LINE__, max_sectors);
  64                 sectors = max_sectors;
  65         }
  66
  67         lpar = dev->bounce_lpar + sector_offset * dev->blk_size;
  68         return ps3flash_read_write_sectors(dev, lpar, start_sector, sectors,
  69                                            0);
  70 }
  71
  72 static ssize_t ps3flash_write_chunk(struct ps3_storage_device *dev,
  73                                     u64 start_sector)
  74 {
  75        u64 sectors = dev->bounce_size / dev->blk_size;
  76        return ps3flash_read_write_sectors(dev, dev->bounce_lpar, start_sector,
  77                                           sectors, 1);
  78 }
  79
  80 static loff_t ps3flash_llseek(struct file *file, loff_t offset, int origin)
  81 {
  82         struct ps3_storage_device *dev = ps3flash_dev;
  83         loff_t res;
  84
  85         mutex_lock(&file->f_mapping->host->i_mutex);
  86         switch (origin) {
  87         case 1:
  88                 offset += file->f_pos;
  89                 break;
  90         case 2:
  91                 offset += dev->regions[dev->region_idx].size*dev->blk_size;
  92                 break;
  93         }
  94         if (offset < 0) {
  95                 res = -EINVAL;
  96                 goto out;
  97         }
  98
  99         file->f_pos = offset;
 100         res = file->f_pos;
 101
 102 out:
 103         mutex_unlock(&file->f_mapping->host->i_mutex);
 104         return res;
 105 }
 106
 107 static ssize_t ps3flash_read(char __user *userbuf, void *kernelbuf,
 108                              size_t count, loff_t *pos)
 109 {
 110         struct ps3_storage_device *dev = ps3flash_dev;
 111         struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
 112         u64 size, start_sector, end_sector, offset;
 113         ssize_t sectors_read;
 114         size_t remaining, n;
 115         const void *src;
 116
 117         dev_dbg(&dev->sbd.core,
 118                 "%s:%u: Reading %zu bytes at position %lld to U0x%p/K0x%p\n",
 119                 __func__, __LINE__, count, *pos, userbuf, kernelbuf);
 120
 121         size = dev->regions[dev->region_idx].size*dev->blk_size;
 122         if (*pos >= size || !count)
 123                 return 0;
 124
 125         if (*pos + count > size) {
 126                 dev_dbg(&dev->sbd.core,
 127                         "%s:%u Truncating count from %zu to %llu\n", __func__,
 128                         __LINE__, count, size - *pos);
 129                 count = size - *pos;
 130         }
 131
 132         start_sector = *pos / dev->blk_size;
 133         offset = *pos % dev->blk_size;
 134         end_sector = DIV_ROUND_UP(*pos + count, dev->blk_size);
 135
 136         remaining = count;
 137         do {
 138                 mutex_lock(&priv->mutex);
 139
 140                 sectors_read = ps3flash_read_sectors(dev, start_sector,
 141                                                      end_sector-start_sector,
 142                                                      0);
 143                 if (sectors_read < 0) {
 144                         mutex_unlock(&priv->mutex);
 145                         goto fail;
 146                 }
 147
 148                 n = min_t(u64, remaining, sectors_read*dev->blk_size-offset);
 149                 src = dev->bounce_buf+offset;
 150                 dev_dbg(&dev->sbd.core,
 151                         "%s:%u: copy %lu bytes from 0x%p to U0x%p/K0x%p\n",
 152                         __func__, __LINE__, n, src, userbuf, kernelbuf);
 153                 if (userbuf) {
 154                         if (copy_to_user(userbuf, src, n)) {
 155                                 mutex_unlock(&priv->mutex);
 156                                 sectors_read = -EFAULT;
 157                                 goto fail;
 158                         }
 159                         userbuf += n;
 160                 }
 161                 if (kernelbuf) {
 162                         memcpy(kernelbuf, src, n);
 163                         kernelbuf += n;
 164                 }
 165
 166                 mutex_unlock(&priv->mutex);
 167
 168                 *pos += n;
 169                 remaining -= n;
 170                 start_sector += sectors_read;
 171                 offset = 0;
 172         } while (remaining > 0);
 173
 174         return count;
 175
 176 fail:
 177         return sectors_read;
 178 }
 179
 180 static ssize_t ps3flash_write(const char __user *userbuf,
 181                               const void *kernelbuf, size_t count, loff_t *pos)
 182 {
 183         struct ps3_storage_device *dev = ps3flash_dev;
 184         struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
 185         u64 size, chunk_sectors, start_write_sector, end_write_sector,
 186             end_read_sector, start_read_sector, head, tail, offset;
 187         ssize_t res;
 188         size_t remaining, n;
 189         unsigned int sec_off;
 190         void *dst;
 191
 192         dev_dbg(&dev->sbd.core,
 193                 "%s:%u: Writing %zu bytes at position %lld from U0x%p/K0x%p\n",
 194                 __func__, __LINE__, count, *pos, userbuf, kernelbuf);
 195
 196         size = dev->regions[dev->region_idx].size*dev->blk_size;
 197         if (*pos >= size || !count)
 198                 return 0;
 199
 200         if (*pos + count > size) {
 201                 dev_dbg(&dev->sbd.core,
 202                         "%s:%u Truncating count from %zu to %llu\n", __func__,
 203                         __LINE__, count, size - *pos);
 204                 count = size - *pos;
 205         }
 206
 207         chunk_sectors = dev->bounce_size / dev->blk_size;
 208
 209         start_write_sector = *pos / dev->bounce_size * chunk_sectors;
 210         offset = *pos % dev->bounce_size;
 211         end_write_sector = DIV_ROUND_UP(*pos + count, dev->bounce_size) *
 212                            chunk_sectors;
 213
 214         end_read_sector = DIV_ROUND_UP(*pos, dev->blk_size);
 215         start_read_sector = (*pos + count) / dev->blk_size;
 216
 217         /*
 218          * As we have to write in 256 KiB chunks, while we can read in blk_size
 219          * (usually 512 bytes) chunks, we perform the following steps:
 220          *   1. Read from start_write_sector to end_read_sector ("head")
 221          *   2. Read from start_read_sector to end_write_sector ("tail")
 222          *   3. Copy data to buffer
 223          *   4. Write from start_write_sector to end_write_sector
 224          * All of this is complicated by using only one 256 KiB bounce buffer.
 225          */
 226
 227         head = end_read_sector - start_write_sector;
 228         tail = end_write_sector - start_read_sector;
 229
 230         remaining = count;
 231         do {
 232                 mutex_lock(&priv->mutex);
 233
 234                 if (end_read_sector >= start_read_sector) {
 235                         /* Merge head and tail */
 236                         dev_dbg(&dev->sbd.core,
 237                                 "Merged head and tail: %llu sectors at %llu\n",
 238                                 chunk_sectors, start_write_sector);
 239                         res = ps3flash_read_sectors(dev, start_write_sector,
 240                                                     chunk_sectors, 0);
 241                         if (res < 0)
 242                                 goto fail;
 243                 } else {
 244                         if (head) {
 245                                 /* Read head */
 246                                 dev_dbg(&dev->sbd.core,
 247                                         "head: %llu sectors at %llu\n", head,
 248                                         start_write_sector);
 249                                 res = ps3flash_read_sectors(dev,
 250                                                             start_write_sector,
 251                                                             head, 0);
 252                                 if (res < 0)
 253                                         goto fail;
 254                         }
 255                         if (start_read_sector <
 256                             start_write_sector+chunk_sectors) {
 257                                 /* Read tail */
 258                                 dev_dbg(&dev->sbd.core,
 259                                         "tail: %llu sectors at %llu\n", tail,
 260                                         start_read_sector);
 261                                 sec_off = start_read_sector-start_write_sector;
 262                                 res = ps3flash_read_sectors(dev,
 263                                                             start_read_sector,
 264                                                             tail, sec_off);
 265                                 if (res < 0)
 266                                         goto fail;
 267                         }
 268                 }
 269
 270                 n = min_t(u64, remaining, dev->bounce_size-offset);
 271                 dst = dev->bounce_buf+offset;
 272                 dev_dbg(&dev->sbd.core,
 273                         "%s:%u: copy %lu bytes from U0x%p/K0x%p to 0x%p\n",
 274                         __func__, __LINE__, n, userbuf, kernelbuf, dst);
 275                 if (userbuf) {
 276                         if (copy_from_user(dst, userbuf, n)) {
 277                                 res = -EFAULT;
 278                                 goto fail;
 279                         }
 280                         userbuf += n;
 281                 }
 282                 if (kernelbuf) {
 283                         memcpy(dst, kernelbuf, n);
 284                         kernelbuf += n;
 285                 }
 286
 287                 res = ps3flash_write_chunk(dev, start_write_sector);
 288                 if (res < 0)
 289                         goto fail;
 290
 291                 mutex_unlock(&priv->mutex);
 292
 293                 *pos += n;
 294                 remaining -= n;
 295                 start_write_sector += chunk_sectors;
 296                 head = 0;
 297                 offset = 0;
 298         } while (remaining > 0);
 299
 300         return count;
 301
 302 fail:
 303         mutex_unlock(&priv->mutex);
 304         return res;
 305 }
 306
 307 static ssize_t ps3flash_user_read(struct file *file, char __user *buf,
 308                                   size_t count, loff_t *pos)
 309 {
 310         return ps3flash_read(buf, NULL, count, pos);
 311 }
 312
 313 static ssize_t ps3flash_user_write(struct file *file, const char __user *buf,
 314                                    size_t count, loff_t *pos)
 315 {
 316         return ps3flash_write(buf, NULL, count, pos);
 317 }
 318
 319 static ssize_t ps3flash_kernel_read(void *buf, size_t count, loff_t pos)
 320 {
 321         return ps3flash_read(NULL, buf, count, &pos);
 322 }
 323
 324 static ssize_t ps3flash_kernel_write(const void *buf, size_t count,
 325                                      loff_t pos)
 326 {
 327         return ps3flash_write(NULL, buf, count, &pos);
 328 }
 329
 330
 331 static irqreturn_t ps3flash_interrupt(int irq, void *data)
 332 {
 333         struct ps3_storage_device *dev = data;
 334         int res;
 335         u64 tag, status;
 336
 337         res = lv1_storage_get_async_status(dev->sbd.dev_id, &tag, &status);
 338
 339         if (tag != dev->tag)
 340                 dev_err(&dev->sbd.core,
 341                         "%s:%u: tag mismatch, got %llx, expected %llx\n",
 342                         __func__, __LINE__, tag, dev->tag);
 343
 344         if (res) {
 345                 dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%llx\n",
 346                         __func__, __LINE__, res, status);
 347         } else {
 348                 dev->lv1_status = status;
 349                 complete(&dev->done);
 350         }
 351         return IRQ_HANDLED;
 352 }
 353
 354 static const struct file_operations ps3flash_fops = {
 355         .owner  = THIS_MODULE,
 356         .llseek = ps3flash_llseek,
 357         .read   = ps3flash_user_read,
 358         .write  = ps3flash_user_write,
 359 };
 360
 361 static const struct ps3_os_area_flash_ops ps3flash_kernel_ops = {
 362         .read   = ps3flash_kernel_read,
 363         .write  = ps3flash_kernel_write,
 364 };
 365
 366 static struct miscdevice ps3flash_misc = {
 367         .minor  = MISC_DYNAMIC_MINOR,
 368         .name   = DEVICE_NAME,
 369         .fops   = &ps3flash_fops,
 370 };
 371
 372 static int __devinit ps3flash_probe(struct ps3_system_bus_device *_dev)
 373 {
 374         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
 375         struct ps3flash_private *priv;
 376         int error;
 377         unsigned long tmp;
 378
 379         tmp = dev->regions[dev->region_idx].start*dev->blk_size;
 380         if (tmp % FLASH_BLOCK_SIZE) {
 381                 dev_err(&dev->sbd.core,
 382                         "%s:%u region start %lu is not aligned\n", __func__,
 383                         __LINE__, tmp);
 384                 return -EINVAL;
 385         }
 386         tmp = dev->regions[dev->region_idx].size*dev->blk_size;
 387         if (tmp % FLASH_BLOCK_SIZE) {
 388                 dev_err(&dev->sbd.core,
 389                         "%s:%u region size %lu is not aligned\n", __func__,
 390                         __LINE__, tmp);
 391                 return -EINVAL;
 392         }
 393
 394         /* use static buffer, kmalloc cannot allocate 256 KiB */
 395         if (!ps3flash_bounce_buffer.address)
 396                 return -ENODEV;
 397
 398         if (ps3flash_dev) {
 399                 dev_err(&dev->sbd.core,
 400                         "Only one FLASH device is supported\n");
 401                 return -EBUSY;
 402         }
 403
 404         ps3flash_dev = dev;
 405
 406         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 407         if (!priv) {
 408                 error = -ENOMEM;
 409                 goto fail;
 410         }
 411
 412         ps3_system_bus_set_drvdata(&dev->sbd, priv);
 413         mutex_init(&priv->mutex);
 414
 415         dev->bounce_size = ps3flash_bounce_buffer.size;
 416         dev->bounce_buf = ps3flash_bounce_buffer.address;
 417
 418         error = ps3stor_setup(dev, ps3flash_interrupt);
 419         if (error)
 420                 goto fail_free_priv;
 421
 422         ps3flash_misc.parent = &dev->sbd.core;
 423         error = misc_register(&ps3flash_misc);
 424         if (error) {
 425                 dev_err(&dev->sbd.core, "%s:%u: misc_register failed %d\n",
 426                         __func__, __LINE__, error);
 427                 goto fail_teardown;
 428         }
 429
 430         dev_info(&dev->sbd.core, "%s:%u: registered misc device %d\n",
 431                  __func__, __LINE__, ps3flash_misc.minor);
 432
 433         ps3_os_area_flash_register(&ps3flash_kernel_ops);
 434         return 0;
 435
 436 fail_teardown:
 437         ps3stor_teardown(dev);
 438 fail_free_priv:
 439         kfree(priv);
 440         ps3_system_bus_set_drvdata(&dev->sbd, NULL);
 441 fail:
 442         ps3flash_dev = NULL;
 443         return error;
 444 }
 445
 446 static int ps3flash_remove(struct ps3_system_bus_device *_dev)
 447 {
 448         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
 449
 450         ps3_os_area_flash_register(NULL);
 451         misc_deregister(&ps3flash_misc);
 452         ps3stor_teardown(dev);
 453         kfree(ps3_system_bus_get_drvdata(&dev->sbd));
 454         ps3_system_bus_set_drvdata(&dev->sbd, NULL);
 455         ps3flash_dev = NULL;
 456         return 0;
 457 }
 458
 459
 460 static struct ps3_system_bus_driver ps3flash = {
 461         .match_id       = PS3_MATCH_ID_STOR_FLASH,
 462         .core.name      = DEVICE_NAME,
 463         .core.owner     = THIS_MODULE,
 464         .probe          = ps3flash_probe,
 465         .remove         = ps3flash_remove,
 466         .shutdown       = ps3flash_remove,
 467 };
 468
 469
 470 static int __init ps3flash_init(void)
 471 {
 472         return ps3_system_bus_driver_register(&ps3flash);
 473 }
 474
 475 static void __exit ps3flash_exit(void)
 476 {
 477         ps3_system_bus_driver_unregister(&ps3flash);
 478 }
 479
 480 module_init(ps3flash_init);
 481 module_exit(ps3flash_exit);
 482
 483 MODULE_LICENSE("GPL");
 484 MODULE_DESCRIPTION("PS3 FLASH ROM Storage Driver");
 485 MODULE_AUTHOR("Sony Corporation");
 486 MODULE_ALIAS(PS3_MODULE_ALIAS_STOR_FLASH);