Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Direct MTD block device access |
| 3 | * |
David Woodhouse | a1452a3 | 2010-08-08 20:58:20 +0100 | [diff] [blame] | 4 | * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> |
| 5 | * Copyright © 2000-2003 Nicolas Pitre <nico@fluxnic.net> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | */ |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/fs.h> |
| 24 | #include <linux/init.h> |
Thomas Gleixner | 15fdc52 | 2005-11-07 00:14:42 +0100 | [diff] [blame] | 25 | #include <linux/kernel.h> |
| 26 | #include <linux/module.h> |
| 27 | #include <linux/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | #include <linux/slab.h> |
Thomas Gleixner | 15fdc52 | 2005-11-07 00:14:42 +0100 | [diff] [blame] | 29 | #include <linux/types.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <linux/vmalloc.h> |
Thomas Gleixner | 15fdc52 | 2005-11-07 00:14:42 +0100 | [diff] [blame] | 31 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <linux/mtd/mtd.h> |
| 33 | #include <linux/mtd/blktrans.h> |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 34 | #include <linux/mutex.h> |
| 35 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 37 | struct mtdblk_dev { |
| 38 | struct mtd_blktrans_dev mbd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | int count; |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 40 | struct mutex cache_mutex; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | unsigned char *cache_data; |
| 42 | unsigned long cache_offset; |
| 43 | unsigned int cache_size; |
| 44 | enum { STATE_EMPTY, STATE_CLEAN, STATE_DIRTY } cache_state; |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 45 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | |
Axel Lin | 7578ca9 | 2011-06-03 14:10:22 +0800 | [diff] [blame] | 47 | static DEFINE_MUTEX(mtdblks_lock); |
Matthias Kaehlcke | d676c11 | 2009-07-14 22:04:29 +0200 | [diff] [blame] | 48 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | /* |
| 50 | * Cache stuff... |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 51 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | * Since typical flash erasable sectors are much larger than what Linux's |
| 53 | * buffer cache can handle, we must implement read-modify-write on flash |
| 54 | * sectors for each block write requests. To avoid over-erasing flash sectors |
| 55 | * and to speed things up, we locally cache a whole flash sector while it is |
| 56 | * being written to until a different sector is required. |
| 57 | */ |
| 58 | |
| 59 | static void erase_callback(struct erase_info *done) |
| 60 | { |
| 61 | wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv; |
| 62 | wake_up(wait_q); |
| 63 | } |
| 64 | |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 65 | static int erase_write (struct mtd_info *mtd, unsigned long pos, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | int len, const char *buf) |
| 67 | { |
| 68 | struct erase_info erase; |
| 69 | DECLARE_WAITQUEUE(wait, current); |
| 70 | wait_queue_head_t wait_q; |
| 71 | size_t retlen; |
| 72 | int ret; |
| 73 | |
| 74 | /* |
| 75 | * First, let's erase the flash block. |
| 76 | */ |
| 77 | |
| 78 | init_waitqueue_head(&wait_q); |
| 79 | erase.mtd = mtd; |
| 80 | erase.callback = erase_callback; |
| 81 | erase.addr = pos; |
| 82 | erase.len = len; |
| 83 | erase.priv = (u_long)&wait_q; |
| 84 | |
| 85 | set_current_state(TASK_INTERRUPTIBLE); |
| 86 | add_wait_queue(&wait_q, &wait); |
| 87 | |
Artem Bityutskiy | 7e1f0dc | 2011-12-23 15:25:39 +0200 | [diff] [blame] | 88 | ret = mtd_erase(mtd, &erase); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | if (ret) { |
| 90 | set_current_state(TASK_RUNNING); |
| 91 | remove_wait_queue(&wait_q, &wait); |
| 92 | printk (KERN_WARNING "mtdblock: erase of region [0x%lx, 0x%x] " |
| 93 | "on \"%s\" failed\n", |
| 94 | pos, len, mtd->name); |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | schedule(); /* Wait for erase to finish. */ |
| 99 | remove_wait_queue(&wait_q, &wait); |
| 100 | |
| 101 | /* |
Matthias Kaehlcke | dff1550 | 2009-07-06 12:02:08 +0200 | [diff] [blame] | 102 | * Next, write the data to flash. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | */ |
| 104 | |
Artem Bityutskiy | eda95cb | 2011-12-23 17:35:41 +0200 | [diff] [blame] | 105 | ret = mtd_write(mtd, pos, len, &retlen, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | if (ret) |
| 107 | return ret; |
| 108 | if (retlen != len) |
| 109 | return -EIO; |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | |
| 114 | static int write_cached_data (struct mtdblk_dev *mtdblk) |
| 115 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 116 | struct mtd_info *mtd = mtdblk->mbd.mtd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | int ret; |
| 118 | |
| 119 | if (mtdblk->cache_state != STATE_DIRTY) |
| 120 | return 0; |
| 121 | |
Brian Norris | 289c052 | 2011-07-19 10:06:09 -0700 | [diff] [blame] | 122 | pr_debug("mtdblock: writing cached data for \"%s\" " |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 123 | "at 0x%lx, size 0x%x\n", mtd->name, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | mtdblk->cache_offset, mtdblk->cache_size); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 125 | |
| 126 | ret = erase_write (mtd, mtdblk->cache_offset, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | mtdblk->cache_size, mtdblk->cache_data); |
| 128 | if (ret) |
| 129 | return ret; |
| 130 | |
| 131 | /* |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 132 | * Here we could arguably set the cache state to STATE_CLEAN. |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 133 | * However this could lead to inconsistency since we will not |
| 134 | * be notified if this content is altered on the flash by other |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | * means. Let's declare it empty and leave buffering tasks to |
| 136 | * the buffer cache instead. |
| 137 | */ |
| 138 | mtdblk->cache_state = STATE_EMPTY; |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 143 | static int do_cached_write (struct mtdblk_dev *mtdblk, unsigned long pos, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | int len, const char *buf) |
| 145 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 146 | struct mtd_info *mtd = mtdblk->mbd.mtd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | unsigned int sect_size = mtdblk->cache_size; |
| 148 | size_t retlen; |
| 149 | int ret; |
| 150 | |
Brian Norris | 289c052 | 2011-07-19 10:06:09 -0700 | [diff] [blame] | 151 | pr_debug("mtdblock: write on \"%s\" at 0x%lx, size 0x%x\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | mtd->name, pos, len); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 153 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | if (!sect_size) |
Artem Bityutskiy | eda95cb | 2011-12-23 17:35:41 +0200 | [diff] [blame] | 155 | return mtd_write(mtd, pos, len, &retlen, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | |
| 157 | while (len > 0) { |
| 158 | unsigned long sect_start = (pos/sect_size)*sect_size; |
| 159 | unsigned int offset = pos - sect_start; |
| 160 | unsigned int size = sect_size - offset; |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 161 | if( size > len ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | size = len; |
| 163 | |
| 164 | if (size == sect_size) { |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 165 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | * We are covering a whole sector. Thus there is no |
| 167 | * need to bother with the cache while it may still be |
| 168 | * useful for other partial writes. |
| 169 | */ |
| 170 | ret = erase_write (mtd, pos, size, buf); |
| 171 | if (ret) |
| 172 | return ret; |
| 173 | } else { |
| 174 | /* Partial sector: need to use the cache */ |
| 175 | |
| 176 | if (mtdblk->cache_state == STATE_DIRTY && |
| 177 | mtdblk->cache_offset != sect_start) { |
| 178 | ret = write_cached_data(mtdblk); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 179 | if (ret) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | return ret; |
| 181 | } |
| 182 | |
| 183 | if (mtdblk->cache_state == STATE_EMPTY || |
| 184 | mtdblk->cache_offset != sect_start) { |
| 185 | /* fill the cache with the current sector */ |
| 186 | mtdblk->cache_state = STATE_EMPTY; |
Artem Bityutskiy | 329ad39 | 2011-12-23 17:30:16 +0200 | [diff] [blame] | 187 | ret = mtd_read(mtd, sect_start, sect_size, |
| 188 | &retlen, mtdblk->cache_data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | if (ret) |
| 190 | return ret; |
| 191 | if (retlen != sect_size) |
| 192 | return -EIO; |
| 193 | |
| 194 | mtdblk->cache_offset = sect_start; |
| 195 | mtdblk->cache_size = sect_size; |
| 196 | mtdblk->cache_state = STATE_CLEAN; |
| 197 | } |
| 198 | |
| 199 | /* write data to our local cache */ |
| 200 | memcpy (mtdblk->cache_data + offset, buf, size); |
| 201 | mtdblk->cache_state = STATE_DIRTY; |
| 202 | } |
| 203 | |
| 204 | buf += size; |
| 205 | pos += size; |
| 206 | len -= size; |
| 207 | } |
| 208 | |
| 209 | return 0; |
| 210 | } |
| 211 | |
| 212 | |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 213 | static int do_cached_read (struct mtdblk_dev *mtdblk, unsigned long pos, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | int len, char *buf) |
| 215 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 216 | struct mtd_info *mtd = mtdblk->mbd.mtd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | unsigned int sect_size = mtdblk->cache_size; |
| 218 | size_t retlen; |
| 219 | int ret; |
| 220 | |
Brian Norris | 289c052 | 2011-07-19 10:06:09 -0700 | [diff] [blame] | 221 | pr_debug("mtdblock: read on \"%s\" at 0x%lx, size 0x%x\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | mtd->name, pos, len); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 223 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | if (!sect_size) |
Artem Bityutskiy | 329ad39 | 2011-12-23 17:30:16 +0200 | [diff] [blame] | 225 | return mtd_read(mtd, pos, len, &retlen, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | |
| 227 | while (len > 0) { |
| 228 | unsigned long sect_start = (pos/sect_size)*sect_size; |
| 229 | unsigned int offset = pos - sect_start; |
| 230 | unsigned int size = sect_size - offset; |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 231 | if (size > len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | size = len; |
| 233 | |
| 234 | /* |
| 235 | * Check if the requested data is already cached |
| 236 | * Read the requested amount of data from our internal cache if it |
| 237 | * contains what we want, otherwise we read the data directly |
| 238 | * from flash. |
| 239 | */ |
| 240 | if (mtdblk->cache_state != STATE_EMPTY && |
| 241 | mtdblk->cache_offset == sect_start) { |
| 242 | memcpy (buf, mtdblk->cache_data + offset, size); |
| 243 | } else { |
Artem Bityutskiy | 329ad39 | 2011-12-23 17:30:16 +0200 | [diff] [blame] | 244 | ret = mtd_read(mtd, pos, size, &retlen, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | if (ret) |
| 246 | return ret; |
| 247 | if (retlen != size) |
| 248 | return -EIO; |
| 249 | } |
| 250 | |
| 251 | buf += size; |
| 252 | pos += size; |
| 253 | len -= size; |
| 254 | } |
| 255 | |
| 256 | return 0; |
| 257 | } |
| 258 | |
| 259 | static int mtdblock_readsect(struct mtd_blktrans_dev *dev, |
| 260 | unsigned long block, char *buf) |
| 261 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 262 | struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | return do_cached_read(mtdblk, block<<9, 512, buf); |
| 264 | } |
| 265 | |
| 266 | static int mtdblock_writesect(struct mtd_blktrans_dev *dev, |
| 267 | unsigned long block, char *buf) |
| 268 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 269 | struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | if (unlikely(!mtdblk->cache_data && mtdblk->cache_size)) { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 271 | mtdblk->cache_data = vmalloc(mtdblk->mbd.mtd->erasesize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | if (!mtdblk->cache_data) |
| 273 | return -EINTR; |
| 274 | /* -EINTR is not really correct, but it is the best match |
| 275 | * documented in man 2 write for all cases. We could also |
| 276 | * return -EAGAIN sometimes, but why bother? |
| 277 | */ |
| 278 | } |
| 279 | return do_cached_write(mtdblk, block<<9, 512, buf); |
| 280 | } |
| 281 | |
| 282 | static int mtdblock_open(struct mtd_blktrans_dev *mbd) |
| 283 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 284 | struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | |
Brian Norris | 289c052 | 2011-07-19 10:06:09 -0700 | [diff] [blame] | 286 | pr_debug("mtdblock_open\n"); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 287 | |
Matthias Kaehlcke | d676c11 | 2009-07-14 22:04:29 +0200 | [diff] [blame] | 288 | mutex_lock(&mtdblks_lock); |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 289 | if (mtdblk->count) { |
| 290 | mtdblk->count++; |
Matthias Kaehlcke | d676c11 | 2009-07-14 22:04:29 +0200 | [diff] [blame] | 291 | mutex_unlock(&mtdblks_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | return 0; |
| 293 | } |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 294 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | /* OK, it's not open. Create cache info for it */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | mtdblk->count = 1; |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 297 | mutex_init(&mtdblk->cache_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | mtdblk->cache_state = STATE_EMPTY; |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 299 | if (!(mbd->mtd->flags & MTD_NO_ERASE) && mbd->mtd->erasesize) { |
| 300 | mtdblk->cache_size = mbd->mtd->erasesize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | mtdblk->cache_data = NULL; |
| 302 | } |
| 303 | |
Matthias Kaehlcke | d676c11 | 2009-07-14 22:04:29 +0200 | [diff] [blame] | 304 | mutex_unlock(&mtdblks_lock); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 305 | |
Brian Norris | 289c052 | 2011-07-19 10:06:09 -0700 | [diff] [blame] | 306 | pr_debug("ok\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | |
| 308 | return 0; |
| 309 | } |
| 310 | |
Al Viro | a8ca889 | 2013-05-05 21:31:22 -0400 | [diff] [blame] | 311 | static void mtdblock_release(struct mtd_blktrans_dev *mbd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 313 | struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | |
Brian Norris | 289c052 | 2011-07-19 10:06:09 -0700 | [diff] [blame] | 315 | pr_debug("mtdblock_release\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | |
Matthias Kaehlcke | d676c11 | 2009-07-14 22:04:29 +0200 | [diff] [blame] | 317 | mutex_lock(&mtdblks_lock); |
| 318 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 319 | mutex_lock(&mtdblk->cache_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | write_cached_data(mtdblk); |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 321 | mutex_unlock(&mtdblk->cache_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | |
| 323 | if (!--mtdblk->count) { |
Alexander Stein | 70d5098 | 2012-01-10 13:26:58 +0100 | [diff] [blame] | 324 | /* |
| 325 | * It was the last usage. Free the cache, but only sync if |
| 326 | * opened for writing. |
| 327 | */ |
| 328 | if (mbd->file_mode & FMODE_WRITE) |
| 329 | mtd_sync(mbd->mtd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | vfree(mtdblk->cache_data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | } |
Matthias Kaehlcke | d676c11 | 2009-07-14 22:04:29 +0200 | [diff] [blame] | 332 | |
| 333 | mutex_unlock(&mtdblks_lock); |
| 334 | |
Brian Norris | 289c052 | 2011-07-19 10:06:09 -0700 | [diff] [blame] | 335 | pr_debug("ok\n"); |
Thomas Gleixner | 97894cd | 2005-11-07 11:15:26 +0000 | [diff] [blame] | 336 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | |
| 338 | static int mtdblock_flush(struct mtd_blktrans_dev *dev) |
| 339 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 340 | struct mtdblk_dev *mtdblk = container_of(dev, struct mtdblk_dev, mbd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 342 | mutex_lock(&mtdblk->cache_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | write_cached_data(mtdblk); |
Ingo Molnar | 48b1926 | 2006-03-31 02:29:41 -0800 | [diff] [blame] | 344 | mutex_unlock(&mtdblk->cache_mutex); |
Artem Bityutskiy | 327cf29 | 2011-12-30 16:35:35 +0200 | [diff] [blame] | 345 | mtd_sync(dev->mtd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | return 0; |
| 347 | } |
| 348 | |
| 349 | static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) |
| 350 | { |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 351 | struct mtdblk_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | |
| 353 | if (!dev) |
| 354 | return; |
| 355 | |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 356 | dev->mbd.mtd = mtd; |
| 357 | dev->mbd.devnum = mtd->index; |
Richard Purdie | 1918767 | 2006-10-27 09:09:33 +0100 | [diff] [blame] | 358 | |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 359 | dev->mbd.size = mtd->size >> 9; |
| 360 | dev->mbd.tr = tr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | |
| 362 | if (!(mtd->flags & MTD_WRITEABLE)) |
Ben Hutchings | cbfe93e | 2010-01-29 20:58:37 +0000 | [diff] [blame] | 363 | dev->mbd.readonly = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | |
Maxim Levitsky | 298304f | 2010-02-22 20:39:31 +0200 | [diff] [blame] | 365 | if (add_mtd_blktrans_dev(&dev->mbd)) |
| 366 | kfree(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | } |
| 368 | |
| 369 | static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev) |
| 370 | { |
| 371 | del_mtd_blktrans_dev(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | } |
| 373 | |
| 374 | static struct mtd_blktrans_ops mtdblock_tr = { |
| 375 | .name = "mtdblock", |
Ezequiel Garcia | 2aabeb2 | 2013-10-08 20:59:08 -0300 | [diff] [blame^] | 376 | .major = MTD_BLOCK_MAJOR, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | .part_bits = 0, |
Richard Purdie | 1918767 | 2006-10-27 09:09:33 +0100 | [diff] [blame] | 378 | .blksize = 512, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | .open = mtdblock_open, |
| 380 | .flush = mtdblock_flush, |
| 381 | .release = mtdblock_release, |
| 382 | .readsect = mtdblock_readsect, |
| 383 | .writesect = mtdblock_writesect, |
| 384 | .add_mtd = mtdblock_add_mtd, |
| 385 | .remove_dev = mtdblock_remove_dev, |
| 386 | .owner = THIS_MODULE, |
| 387 | }; |
| 388 | |
| 389 | static int __init init_mtdblock(void) |
| 390 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | return register_mtd_blktrans(&mtdblock_tr); |
| 392 | } |
| 393 | |
| 394 | static void __exit cleanup_mtdblock(void) |
| 395 | { |
| 396 | deregister_mtd_blktrans(&mtdblock_tr); |
| 397 | } |
| 398 | |
| 399 | module_init(init_mtdblock); |
| 400 | module_exit(cleanup_mtdblock); |
| 401 | |
| 402 | |
| 403 | MODULE_LICENSE("GPL"); |
Nicolas Pitre | 2f82af0 | 2009-09-14 03:25:28 -0400 | [diff] [blame] | 404 | MODULE_AUTHOR("Nicolas Pitre <nico@fluxnic.net> et al."); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | MODULE_DESCRIPTION("Caching read/erase/writeback block device emulation access to MTD devices"); |