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(struct file *file, char __user *buf, size_t count,
 108                              loff_t *pos)
 109 {
 110         struct ps3_storage_device *dev = ps3flash_dev;
 111         struct ps3flash_private *priv = dev->sbd.core.driver_data;
 112         u64 size, start_sector, end_sector, offset;
 113         ssize_t sectors_read;
 114         size_t remaining, n;
 115
 116         dev_dbg(&dev->sbd.core,
 117                 "%s:%u: Reading %zu bytes at position %lld to user 0x%p\n",
 118                 __func__, __LINE__, count, *pos, buf);
 119
 120         size = dev->regions[dev->region_idx].size*dev->blk_size;
 121         if (*pos >= size || !count)
 122                 return 0;
 123
 124         if (*pos + count > size) {
 125                 dev_dbg(&dev->sbd.core,
 126                         "%s:%u Truncating count from %zu to %llu\n", __func__,
 127                         __LINE__, count, size - *pos);
 128                 count = size - *pos;
 129         }
 130
 131         start_sector = *pos / dev->blk_size;
 132         offset = *pos % dev->blk_size;
 133         end_sector = DIV_ROUND_UP(*pos + count, dev->blk_size);
 134
 135         remaining = count;
 136         do {
 137                 mutex_lock(&priv->mutex);
 138
 139                 sectors_read = ps3flash_read_sectors(dev, start_sector,
 140                                                      end_sector-start_sector,
 141                                                      0);
 142                 if (sectors_read < 0) {
 143                         mutex_unlock(&priv->mutex);
 144                         goto fail;
 145                 }
 146
 147                 n = min_t(u64, remaining, sectors_read*dev->blk_size-offset);
 148                 dev_dbg(&dev->sbd.core,
 149                         "%s:%u: copy %lu bytes from 0x%p to user 0x%p\n",
 150                         __func__, __LINE__, n, dev->bounce_buf+offset, buf);
 151                 if (copy_to_user(buf, dev->bounce_buf+offset, n)) {
 152                         mutex_unlock(&priv->mutex);
 153                         sectors_read = -EFAULT;
 154                         goto fail;
 155                 }
 156
 157                 mutex_unlock(&priv->mutex);
 158
 159                 *pos += n;
 160                 buf += n;
 161                 remaining -= n;
 162                 start_sector += sectors_read;
 163                 offset = 0;
 164         } while (remaining > 0);
 165
 166         return count;
 167
 168 fail:
 169         return sectors_read;
 170 }
 171
 172 static ssize_t ps3flash_write(struct file *file, const char __user *buf,
 173                               size_t count, loff_t *pos)
 174 {
 175         struct ps3_storage_device *dev = ps3flash_dev;
 176         struct ps3flash_private *priv = dev->sbd.core.driver_data;
 177         u64 size, chunk_sectors, start_write_sector, end_write_sector,
 178             end_read_sector, start_read_sector, head, tail, offset;
 179         ssize_t res;
 180         size_t remaining, n;
 181         unsigned int sec_off;
 182
 183         dev_dbg(&dev->sbd.core,
 184                 "%s:%u: Writing %zu bytes at position %lld from user 0x%p\n",
 185                 __func__, __LINE__, count, *pos, buf);
 186
 187         size = dev->regions[dev->region_idx].size*dev->blk_size;
 188         if (*pos >= size || !count)
 189                 return 0;
 190
 191         if (*pos + count > size) {
 192                 dev_dbg(&dev->sbd.core,
 193                         "%s:%u Truncating count from %zu to %llu\n", __func__,
 194                         __LINE__, count, size - *pos);
 195                 count = size - *pos;
 196         }
 197
 198         chunk_sectors = dev->bounce_size / dev->blk_size;
 199
 200         start_write_sector = *pos / dev->bounce_size * chunk_sectors;
 201         offset = *pos % dev->bounce_size;
 202         end_write_sector = DIV_ROUND_UP(*pos + count, dev->bounce_size) *
 203                            chunk_sectors;
 204
 205         end_read_sector = DIV_ROUND_UP(*pos, dev->blk_size);
 206         start_read_sector = (*pos + count) / dev->blk_size;
 207
 208         /*
 209          * As we have to write in 256 KiB chunks, while we can read in blk_size
 210          * (usually 512 bytes) chunks, we perform the following steps:
 211          *   1. Read from start_write_sector to end_read_sector ("head")
 212          *   2. Read from start_read_sector to end_write_sector ("tail")
 213          *   3. Copy data to buffer
 214          *   4. Write from start_write_sector to end_write_sector
 215          * All of this is complicated by using only one 256 KiB bounce buffer.
 216          */
 217
 218         head = end_read_sector - start_write_sector;
 219         tail = end_write_sector - start_read_sector;
 220
 221         remaining = count;
 222         do {
 223                 mutex_lock(&priv->mutex);
 224
 225                 if (end_read_sector >= start_read_sector) {
 226                         /* Merge head and tail */
 227                         dev_dbg(&dev->sbd.core,
 228                                 "Merged head and tail: %llu sectors at %llu\n",
 229                                 chunk_sectors, start_write_sector);
 230                         res = ps3flash_read_sectors(dev, start_write_sector,
 231                                                     chunk_sectors, 0);
 232                         if (res < 0)
 233                                 goto fail;
 234                 } else {
 235                         if (head) {
 236                                 /* Read head */
 237                                 dev_dbg(&dev->sbd.core,
 238                                         "head: %llu sectors at %llu\n", head,
 239                                         start_write_sector);
 240                                 res = ps3flash_read_sectors(dev,
 241                                                             start_write_sector,
 242                                                             head, 0);
 243                                 if (res < 0)
 244                                         goto fail;
 245                         }
 246                         if (start_read_sector <
 247                             start_write_sector+chunk_sectors) {
 248                                 /* Read tail */
 249                                 dev_dbg(&dev->sbd.core,
 250                                         "tail: %llu sectors at %llu\n", tail,
 251                                         start_read_sector);
 252                                 sec_off = start_read_sector-start_write_sector;
 253                                 res = ps3flash_read_sectors(dev,
 254                                                             start_read_sector,
 255                                                             tail, sec_off);
 256                                 if (res < 0)
 257                                         goto fail;
 258                         }
 259                 }
 260
 261                 n = min_t(u64, remaining, dev->bounce_size-offset);
 262                 dev_dbg(&dev->sbd.core,
 263                         "%s:%u: copy %lu bytes from user 0x%p to 0x%p\n",
 264                         __func__, __LINE__, n, buf, dev->bounce_buf+offset);
 265                 if (copy_from_user(dev->bounce_buf+offset, buf, n)) {
 266                         res = -EFAULT;
 267                         goto fail;
 268                 }
 269
 270                 res = ps3flash_write_chunk(dev, start_write_sector);
 271                 if (res < 0)
 272                         goto fail;
 273
 274                 mutex_unlock(&priv->mutex);
 275
 276                 *pos += n;
 277                 buf += n;
 278                 remaining -= n;
 279                 start_write_sector += chunk_sectors;
 280                 head = 0;
 281                 offset = 0;
 282         } while (remaining > 0);
 283
 284         return count;
 285
 286 fail:
 287         mutex_unlock(&priv->mutex);
 288         return res;
 289 }
 290
 291
 292 static irqreturn_t ps3flash_interrupt(int irq, void *data)
 293 {
 294         struct ps3_storage_device *dev = data;
 295         int res;
 296         u64 tag, status;
 297
 298         res = lv1_storage_get_async_status(dev->sbd.dev_id, &tag, &status);
 299
 300         if (tag != dev->tag)
 301                 dev_err(&dev->sbd.core,
 302                         "%s:%u: tag mismatch, got %llx, expected %llx\n",
 303                         __func__, __LINE__, tag, dev->tag);
 304
 305         if (res) {
 306                 dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%llx\n",
 307                         __func__, __LINE__, res, status);
 308         } else {
 309                 dev->lv1_status = status;
 310                 complete(&dev->done);
 311         }
 312         return IRQ_HANDLED;
 313 }
 314
 315
 316 static const struct file_operations ps3flash_fops = {
 317         .owner  = THIS_MODULE,
 318         .llseek = ps3flash_llseek,
 319         .read   = ps3flash_read,
 320         .write  = ps3flash_write,
 321 };
 322
 323 static struct miscdevice ps3flash_misc = {
 324         .minor  = MISC_DYNAMIC_MINOR,
 325         .name   = DEVICE_NAME,
 326         .fops   = &ps3flash_fops,
 327 };
 328
 329 static int __devinit ps3flash_probe(struct ps3_system_bus_device *_dev)
 330 {
 331         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
 332         struct ps3flash_private *priv;
 333         int error;
 334         unsigned long tmp;
 335
 336         tmp = dev->regions[dev->region_idx].start*dev->blk_size;
 337         if (tmp % FLASH_BLOCK_SIZE) {
 338                 dev_err(&dev->sbd.core,
 339                         "%s:%u region start %lu is not aligned\n", __func__,
 340                         __LINE__, tmp);
 341                 return -EINVAL;
 342         }
 343         tmp = dev->regions[dev->region_idx].size*dev->blk_size;
 344         if (tmp % FLASH_BLOCK_SIZE) {
 345                 dev_err(&dev->sbd.core,
 346                         "%s:%u region size %lu is not aligned\n", __func__,
 347                         __LINE__, tmp);
 348                 return -EINVAL;
 349         }
 350
 351         /* use static buffer, kmalloc cannot allocate 256 KiB */
 352         if (!ps3flash_bounce_buffer.address)
 353                 return -ENODEV;
 354
 355         if (ps3flash_dev) {
 356                 dev_err(&dev->sbd.core,
 357                         "Only one FLASH device is supported\n");
 358                 return -EBUSY;
 359         }
 360
 361         ps3flash_dev = dev;
 362
 363         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 364         if (!priv) {
 365                 error = -ENOMEM;
 366                 goto fail;
 367         }
 368
 369         dev->sbd.core.driver_data = priv;
 370         mutex_init(&priv->mutex);
 371
 372         dev->bounce_size = ps3flash_bounce_buffer.size;
 373         dev->bounce_buf = ps3flash_bounce_buffer.address;
 374
 375         error = ps3stor_setup(dev, ps3flash_interrupt);
 376         if (error)
 377                 goto fail_free_priv;
 378
 379         ps3flash_misc.parent = &dev->sbd.core;
 380         error = misc_register(&ps3flash_misc);
 381         if (error) {
 382                 dev_err(&dev->sbd.core, "%s:%u: misc_register failed %d\n",
 383                         __func__, __LINE__, error);
 384                 goto fail_teardown;
 385         }
 386
 387         dev_info(&dev->sbd.core, "%s:%u: registered misc device %d\n",
 388                  __func__, __LINE__, ps3flash_misc.minor);
 389         return 0;
 390
 391 fail_teardown:
 392         ps3stor_teardown(dev);
 393 fail_free_priv:
 394         kfree(priv);
 395         dev->sbd.core.driver_data = NULL;
 396 fail:
 397         ps3flash_dev = NULL;
 398         return error;
 399 }
 400
 401 static int ps3flash_remove(struct ps3_system_bus_device *_dev)
 402 {
 403         struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
 404
 405         misc_deregister(&ps3flash_misc);
 406         ps3stor_teardown(dev);
 407         kfree(dev->sbd.core.driver_data);
 408         dev->sbd.core.driver_data = NULL;
 409         ps3flash_dev = NULL;
 410         return 0;
 411 }
 412
 413
 414 static struct ps3_system_bus_driver ps3flash = {
 415         .match_id       = PS3_MATCH_ID_STOR_FLASH,
 416         .core.name      = DEVICE_NAME,
 417         .core.owner     = THIS_MODULE,
 418         .probe          = ps3flash_probe,
 419         .remove         = ps3flash_remove,
 420         .shutdown       = ps3flash_remove,
 421 };
 422
 423
 424 static int __init ps3flash_init(void)
 425 {
 426         return ps3_system_bus_driver_register(&ps3flash);
 427 }
 428
 429 static void __exit ps3flash_exit(void)
 430 {
 431         ps3_system_bus_driver_unregister(&ps3flash);
 432 }
 433
 434 module_init(ps3flash_init);
 435 module_exit(ps3flash_exit);
 436
 437 MODULE_LICENSE("GPL");
 438 MODULE_DESCRIPTION("PS3 FLASH ROM Storage Driver");
 439 MODULE_AUTHOR("Sony Corporation");
 440 MODULE_ALIAS(PS3_MODULE_ALIAS_STOR_FLASH);