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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [mtd/] [mtdblock_ro.c] - Blame information for rev 1765

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Line No. Rev Author Line
1 1275 phoenix
/*
2
 * $Id: mtdblock_ro.c,v 1.1.1.1 2004-04-15 01:51:40 phoenix Exp $
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 *
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 * Read-only version of the mtdblock device, without the
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 * read/erase/modify/writeback stuff
6
 */
7
 
8
#ifdef MTDBLOCK_DEBUG
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#define DEBUGLVL debug
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#endif                                                         
11
 
12
 
13
#include <linux/module.h>
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#include <linux/types.h>
15
 
16
#include <linux/mtd/mtd.h>
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#include <linux/mtd/compatmac.h>
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#define MAJOR_NR MTD_BLOCK_MAJOR
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#define DEVICE_NAME "mtdblock"
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#define DEVICE_REQUEST mtdblock_request
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#define DEVICE_NR(device) (device)
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#define DEVICE_ON(device)
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#define DEVICE_OFF(device)
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#define DEVICE_NO_RANDOM
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#include <linux/blk.h>
27
 
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#if LINUX_VERSION_CODE < 0x20300
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#define RQFUNC_ARG void
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#define blkdev_dequeue_request(req) do {CURRENT = req->next;} while (0)
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#else
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#define RQFUNC_ARG request_queue_t *q
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#endif
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#ifdef MTDBLOCK_DEBUG
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static int debug = MTDBLOCK_DEBUG;
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MODULE_PARM(debug, "i");
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#endif
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#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,14)
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#define BLK_INC_USE_COUNT MOD_INC_USE_COUNT
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#define BLK_DEC_USE_COUNT MOD_DEC_USE_COUNT
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#else
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#define BLK_INC_USE_COUNT do {} while(0)
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#define BLK_DEC_USE_COUNT do {} while(0)
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#endif
47
 
48
static int mtd_sizes[MAX_MTD_DEVICES];
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50
 
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static int mtdblock_open(struct inode *inode, struct file *file)
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{
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        struct mtd_info *mtd = NULL;
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55
        int dev;
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        DEBUG(1,"mtdblock_open\n");
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        if (inode == 0)
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                return -EINVAL;
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        dev = MINOR(inode->i_rdev);
63
 
64
        mtd = get_mtd_device(NULL, dev);
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        if (!mtd)
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                return -EINVAL;
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        if (MTD_ABSENT == mtd->type) {
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                put_mtd_device(mtd);
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                return -EINVAL;
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        }
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        BLK_INC_USE_COUNT;
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        mtd_sizes[dev] = mtd->size>>9;
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        DEBUG(1, "ok\n");
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        return 0;
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}
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static release_t mtdblock_release(struct inode *inode, struct file *file)
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{
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        int dev;
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        struct mtd_info *mtd;
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86
        DEBUG(1, "mtdblock_release\n");
87
 
88
        if (inode == NULL)
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                release_return(-ENODEV);
90
 
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        dev = MINOR(inode->i_rdev);
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        mtd = __get_mtd_device(NULL, dev);
93
 
94
        if (!mtd) {
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                printk(KERN_WARNING "MTD device is absent on mtd_release!\n");
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                BLK_DEC_USE_COUNT;
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                release_return(-ENODEV);
98
        }
99
 
100
        if (mtd->sync)
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                mtd->sync(mtd);
102
 
103
        put_mtd_device(mtd);
104
 
105
        DEBUG(1, "ok\n");
106
 
107
        BLK_DEC_USE_COUNT;
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        release_return(0);
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}
110
 
111
 
112
static void mtdblock_request(RQFUNC_ARG)
113
{
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   struct request *current_request;
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   unsigned int res = 0;
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   struct mtd_info *mtd;
117
 
118
   while (1)
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   {
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      /* Grab the Request and unlink it from the request list, INIT_REQUEST
121
         will execute a return if we are done. */
122
      INIT_REQUEST;
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      current_request = CURRENT;
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      if (MINOR(current_request->rq_dev) >= MAX_MTD_DEVICES)
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      {
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         printk("mtd: Unsupported device!\n");
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         end_request(0);
129
         continue;
130
      }
131
 
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      // Grab our MTD structure
133
 
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      mtd = __get_mtd_device(NULL, MINOR(current_request->rq_dev));
135
      if (!mtd) {
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              printk("MTD device %d doesn't appear to exist any more\n", CURRENT_DEV);
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              end_request(0);
138
      }
139
 
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      if (current_request->sector << 9 > mtd->size ||
141
          (current_request->sector + current_request->current_nr_sectors) << 9 > mtd->size)
142
      {
143
         printk("mtd: Attempt to read past end of device!\n");
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         printk("size: %x, sector: %lx, nr_sectors %lx\n", mtd->size,
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                current_request->sector, current_request->current_nr_sectors);
146
         end_request(0);
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         continue;
148
      }
149
 
150
      /* Remove the request we are handling from the request list so nobody messes
151
         with it */
152
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
153
      /* Now drop the lock that the ll_rw_blk functions grabbed for us
154
         and process the request. This is necessary due to the extreme time
155
         we spend processing it. */
156
      spin_unlock_irq(&io_request_lock);
157
#endif
158
 
159
      // Handle the request
160
      switch (current_request->cmd)
161
      {
162
         size_t retlen;
163
 
164
         case READ:
165
         if (MTD_READ(mtd,current_request->sector<<9,
166
                      current_request->current_nr_sectors << 9,
167
                      &retlen, current_request->buffer) == 0)
168
            res = 1;
169
         else
170
            res = 0;
171
         break;
172
 
173
         case WRITE:
174
 
175
         /* printk("mtdblock_request WRITE sector=%d(%d)\n",current_request->sector,
176
                current_request->current_nr_sectors);
177
         */
178
 
179
         // Read only device
180
         if ((mtd->flags & MTD_CAP_RAM) == 0)
181
         {
182
            res = 0;
183
            break;
184
         }
185
 
186
         // Do the write
187
         if (MTD_WRITE(mtd,current_request->sector<<9,
188
                       current_request->current_nr_sectors << 9,
189
                       &retlen, current_request->buffer) == 0)
190
            res = 1;
191
         else
192
            res = 0;
193
         break;
194
 
195
         // Shouldn't happen
196
         default:
197
         printk("mtd: unknown request\n");
198
         break;
199
      }
200
 
201
      // Grab the lock and re-thread the item onto the linked list
202
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
203
        spin_lock_irq(&io_request_lock);
204
#endif
205
        end_request(res);
206
   }
207
}
208
 
209
 
210
 
211
static int mtdblock_ioctl(struct inode * inode, struct file * file,
212
                      unsigned int cmd, unsigned long arg)
213
{
214
        struct mtd_info *mtd;
215
 
216
        mtd = __get_mtd_device(NULL, MINOR(inode->i_rdev));
217
 
218
        if (!mtd) return -EINVAL;
219
 
220
        switch (cmd) {
221
        case BLKGETSIZE:   /* Return device size */
222
                return put_user((mtd->size >> 9), (unsigned long *) arg);
223
 
224
#ifdef BLKGETSIZE64
225
        case BLKGETSIZE64:
226
                return put_user((u64)mtd->size, (u64 *)arg);
227
#endif
228
 
229
        case BLKFLSBUF:
230
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
231
                if(!capable(CAP_SYS_ADMIN))  return -EACCES;
232
#endif
233
                fsync_dev(inode->i_rdev);
234
                invalidate_buffers(inode->i_rdev);
235
                if (mtd->sync)
236
                        mtd->sync(mtd);
237
                return 0;
238
 
239
        default:
240
                return -ENOTTY;
241
        }
242
}
243
 
244
#if LINUX_VERSION_CODE < 0x20326
245
static struct file_operations mtd_fops =
246
{
247
        open: mtdblock_open,
248
        ioctl: mtdblock_ioctl,
249
        release: mtdblock_release,
250
        read: block_read,
251
        write: block_write
252
};
253
#else
254
static struct block_device_operations mtd_fops =
255
{
256
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,14)
257
        owner: THIS_MODULE,
258
#endif
259
        open: mtdblock_open,
260
        release: mtdblock_release,
261
        ioctl: mtdblock_ioctl
262
};
263
#endif
264
 
265
int __init init_mtdblock(void)
266
{
267
        int i;
268
 
269
        if (register_blkdev(MAJOR_NR,DEVICE_NAME,&mtd_fops)) {
270
                printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
271
                       MTD_BLOCK_MAJOR);
272
                return -EAGAIN;
273
        }
274
 
275
        /* We fill it in at open() time. */
276
        for (i=0; i< MAX_MTD_DEVICES; i++) {
277
                mtd_sizes[i] = 0;
278
        }
279
 
280
        /* Allow the block size to default to BLOCK_SIZE. */
281
        blksize_size[MAJOR_NR] = NULL;
282
        blk_size[MAJOR_NR] = mtd_sizes;
283
 
284
        blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), &mtdblock_request);
285
        return 0;
286
}
287
 
288
static void __exit cleanup_mtdblock(void)
289
{
290
        unregister_blkdev(MAJOR_NR,DEVICE_NAME);
291
        blk_size[MAJOR_NR] = NULL;
292
        blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
293
}
294
 
295
module_init(init_mtdblock);
296
module_exit(cleanup_mtdblock);
297
 
298
 
299
MODULE_LICENSE("GPL");
300
MODULE_AUTHOR("Erwin Authried <eauth@softsys.co.at> et al.");
301
MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");

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