Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2 ** z2ram - Amiga pseudo-driver to access 16bit-RAM in ZorroII space
  3 **         as a block device, to be used as a RAM disk or swap space
  4 ** 
  5 ** Copyright (C) 1994 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)
  6 **
  7 ** ++Geert: support for zorro_unused_z2ram, better range checking
  8 ** ++roman: translate accesses via an array
  9 ** ++Milan: support for ChipRAM usage
 10 ** ++yambo: converted to 2.0 kernel
 11 ** ++yambo: modularized and support added for 3 minor devices including:
 12 **          MAJOR  MINOR  DESCRIPTION
 13 **          -----  -----  ----------------------------------------------
 14 **          37     0       Use Zorro II and Chip ram
 15 **          37     1       Use only Zorro II ram
 16 **          37     2       Use only Chip ram
 17 **          37     4-7     Use memory list entry 1-4 (first is 0)
 18 ** ++jskov: support for 1-4th memory list entry.
 19 **
 20 ** Permission to use, copy, modify, and distribute this software and its
 21 ** documentation for any purpose and without fee is hereby granted, provided
 22 ** that the above copyright notice appear in all copies and that both that
 23 ** copyright notice and this permission notice appear in supporting
 24 ** documentation.  This software is provided "as is" without express or
 25 ** implied warranty.
 26 */
 27 
 28 #define DEVICE_NAME "Z2RAM"
 29 
 30 #include <linux/major.h>
 31 #include <linux/vmalloc.h>
 32 #include <linux/init.h>
 33 #include <linux/module.h>
 34 #include <linux/blkdev.h>
 35 #include <linux/bitops.h>
 36 
 37 #include <asm/setup.h>
 38 #include <asm/amigahw.h>
 39 #include <asm/pgtable.h>
 40 
 41 #include <linux/zorro.h>
 42 
 43 
 44 extern int m68k_realnum_memory;
 45 extern struct mem_info m68k_memory[NUM_MEMINFO];
 46 
 47 #define Z2MINOR_COMBINED      (0)
 48 #define Z2MINOR_Z2ONLY        (1)
 49 #define Z2MINOR_CHIPONLY      (2)
 50 #define Z2MINOR_MEMLIST1      (4)
 51 #define Z2MINOR_MEMLIST2      (5)
 52 #define Z2MINOR_MEMLIST3      (6)
 53 #define Z2MINOR_MEMLIST4      (7)
 54 #define Z2MINOR_COUNT         (8) /* Move this down when adding a new minor */
 55 
 56 #define Z2RAM_CHUNK1024       ( Z2RAM_CHUNKSIZE >> 10 )
 57 
 58 static u_long *z2ram_map    = NULL;
 59 static u_long z2ram_size    = 0;
 60 static int z2_count         = 0;
 61 static int chip_count       = 0;
 62 static int list_count       = 0;
 63 static int current_device   = -1;
 64 
 65 static DEFINE_SPINLOCK(z2ram_lock);
 66 
 67 static struct block_device_operations z2_fops;
 68 static struct gendisk *z2ram_gendisk;
 69 
 70 static void do_z2_request(struct request_queue *q)
 71 {
 72         struct request *req;
 73         while ((req = elv_next_request(q)) != NULL) {
 74                 unsigned long start = req->sector << 9;
 75                 unsigned long len  = req->current_nr_sectors << 9;
 76 
 77                 if (start + len > z2ram_size) {
 78                         printk( KERN_ERR DEVICE_NAME ": bad access: block=%lu, count=%u\n",
 79                                 req->sector, req->current_nr_sectors);
 80                         end_request(req, 0);
 81                         continue;
 82                 }
 83                 while (len) {
 84                         unsigned long addr = start & Z2RAM_CHUNKMASK;
 85                         unsigned long size = Z2RAM_CHUNKSIZE - addr;
 86                         if (len < size)
 87                                 size = len;
 88                         addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
 89                         if (rq_data_dir(req) == READ)
 90                                 memcpy(req->buffer, (char *)addr, size);
 91                         else
 92                                 memcpy((char *)addr, req->buffer, size);
 93                         start += size;
 94                         len -= size;
 95                 }
 96                 end_request(req, 1);
 97         }
 98 }
 99 
100 static void
101 get_z2ram( void )
102 {
103     int i;
104 
105     for ( i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++ )
106     {
107         if ( test_bit( i, zorro_unused_z2ram ) )
108         {
109             z2_count++;
110             z2ram_map[ z2ram_size++ ] = 
111                 ZTWO_VADDR( Z2RAM_START ) + ( i << Z2RAM_CHUNKSHIFT );
112             clear_bit( i, zorro_unused_z2ram );
113         }
114     }
115 
116     return;
117 }
118 
119 static void
120 get_chipram( void )
121 {
122 
123     while ( amiga_chip_avail() > ( Z2RAM_CHUNKSIZE * 4 ) )
124     {
125         chip_count++;
126         z2ram_map[ z2ram_size ] =
127             (u_long)amiga_chip_alloc( Z2RAM_CHUNKSIZE, "z2ram" );
128 
129         if ( z2ram_map[ z2ram_size ] == 0 )
130         {
131             break;
132         }
133 
134         z2ram_size++;
135     }
136         
137     return;
138 }
139 
140 static int
141 z2_open( struct inode *inode, struct file *filp )
142 {
143     int device;
144     int max_z2_map = ( Z2RAM_SIZE / Z2RAM_CHUNKSIZE ) *
145         sizeof( z2ram_map[0] );
146     int max_chip_map = ( amiga_chip_size / Z2RAM_CHUNKSIZE ) *
147         sizeof( z2ram_map[0] );
148     int rc = -ENOMEM;
149 
150     device = iminor(inode);
151 
152     if ( current_device != -1 && current_device != device )
153     {
154         rc = -EBUSY;
155         goto err_out;
156     }
157 
158     if ( current_device == -1 )
159     {
160         z2_count   = 0;
161         chip_count = 0;
162         list_count = 0;
163         z2ram_size = 0;
164 
165         /* Use a specific list entry. */
166         if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
167                 int index = device - Z2MINOR_MEMLIST1 + 1;
168                 unsigned long size, paddr, vaddr;
169 
170                 if (index >= m68k_realnum_memory) {
171                         printk( KERN_ERR DEVICE_NAME
172                                 ": no such entry in z2ram_map\n" );
173                         goto err_out;
174                 }
175 
176                 paddr = m68k_memory[index].addr;
177                 size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE-1);
178 
179 #ifdef __powerpc__
180                 /* FIXME: ioremap doesn't build correct memory tables. */
181                 {
182                         vfree(vmalloc (size));
183                 }
184 
185                 vaddr = (unsigned long) __ioremap (paddr, size, 
186                                                    _PAGE_WRITETHRU);
187 
188 #else
189                 vaddr = (unsigned long)z_remap_nocache_nonser(paddr, size);
190 #endif
191                 z2ram_map = 
192                         kmalloc((size/Z2RAM_CHUNKSIZE)*sizeof(z2ram_map[0]),
193                                 GFP_KERNEL);
194                 if ( z2ram_map == NULL )
195                 {
196                     printk( KERN_ERR DEVICE_NAME
197                         ": cannot get mem for z2ram_map\n" );
198                     goto err_out;
199                 }
200 
201                 while (size) {
202                         z2ram_map[ z2ram_size++ ] = vaddr;
203                         size -= Z2RAM_CHUNKSIZE;
204                         vaddr += Z2RAM_CHUNKSIZE;
205                         list_count++;
206                 }
207 
208                 if ( z2ram_size != 0 )
209                     printk( KERN_INFO DEVICE_NAME
210                         ": using %iK List Entry %d Memory\n",
211                         list_count * Z2RAM_CHUNK1024, index );
212         } else
213 
214         switch ( device )
215         {
216             case Z2MINOR_COMBINED:
217 
218                 z2ram_map = kmalloc( max_z2_map + max_chip_map, GFP_KERNEL );
219                 if ( z2ram_map == NULL )
220                 {
221                     printk( KERN_ERR DEVICE_NAME
222                         ": cannot get mem for z2ram_map\n" );
223                     goto err_out;
224                 }
225 
226                 get_z2ram();
227                 get_chipram();
228 
229                 if ( z2ram_size != 0 )
230                     printk( KERN_INFO DEVICE_NAME 
231                         ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
232                         z2_count * Z2RAM_CHUNK1024,
233                         chip_count * Z2RAM_CHUNK1024,
234                         ( z2_count + chip_count ) * Z2RAM_CHUNK1024 );
235 
236             break;
237 
238             case Z2MINOR_Z2ONLY:
239                 z2ram_map = kmalloc( max_z2_map, GFP_KERNEL );
240                 if ( z2ram_map == NULL )
241                 {
242                     printk( KERN_ERR DEVICE_NAME
243                         ": cannot get mem for z2ram_map\n" );
244                     goto err_out;
245                 }
246 
247                 get_z2ram();
248 
249                 if ( z2ram_size != 0 )
250                     printk( KERN_INFO DEVICE_NAME 
251                         ": using %iK of Zorro II RAM\n",
252                         z2_count * Z2RAM_CHUNK1024 );
253 
254             break;
255 
256             case Z2MINOR_CHIPONLY:
257                 z2ram_map = kmalloc( max_chip_map, GFP_KERNEL );
258                 if ( z2ram_map == NULL )
259                 {
260                     printk( KERN_ERR DEVICE_NAME
261                         ": cannot get mem for z2ram_map\n" );
262                     goto err_out;
263                 }
264 
265                 get_chipram();
266 
267                 if ( z2ram_size != 0 )
268                     printk( KERN_INFO DEVICE_NAME 
269                         ": using %iK Chip RAM\n",
270                         chip_count * Z2RAM_CHUNK1024 );
271                     
272             break;
273 
274             default:
275                 rc = -ENODEV;
276                 goto err_out;
277         
278             break;
279         }
280 
281         if ( z2ram_size == 0 )
282         {
283             printk( KERN_NOTICE DEVICE_NAME
284                 ": no unused ZII/Chip RAM found\n" );
285             goto err_out_kfree;
286         }
287 
288         current_device = device;
289         z2ram_size <<= Z2RAM_CHUNKSHIFT;
290         set_capacity(z2ram_gendisk, z2ram_size >> 9);
291     }
292 
293     return 0;
294 
295 err_out_kfree:
296     kfree(z2ram_map);
297 err_out:
298     return rc;
299 }
300 
301 static int
302 z2_release( struct inode *inode, struct file *filp )
303 {
304     if ( current_device == -1 )
305         return 0;     
306 
307     /*
308      * FIXME: unmap memory
309      */
310 
311     return 0;
312 }
313 
314 static struct block_device_operations z2_fops =
315 {
316         .owner          = THIS_MODULE,
317         .open           = z2_open,
318         .release        = z2_release,
319 };
320 
321 static struct kobject *z2_find(dev_t dev, int *part, void *data)
322 {
323         *part = 0;
324         return get_disk(z2ram_gendisk);
325 }
326 
327 static struct request_queue *z2_queue;
328 
329 static int __init 
330 z2_init(void)
331 {
332     int ret;
333 
334     if (!MACH_IS_AMIGA)
335         return -ENXIO;
336 
337     ret = -EBUSY;
338     if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
339         goto err;
340 
341     ret = -ENOMEM;
342     z2ram_gendisk = alloc_disk(1);
343     if (!z2ram_gendisk)
344         goto out_disk;
345 
346     z2_queue = blk_init_queue(do_z2_request, &z2ram_lock);
347     if (!z2_queue)
348         goto out_queue;
349 
350     z2ram_gendisk->major = Z2RAM_MAJOR;
351     z2ram_gendisk->first_minor = 0;
352     z2ram_gendisk->fops = &z2_fops;
353     sprintf(z2ram_gendisk->disk_name, "z2ram");
354 
355     z2ram_gendisk->queue = z2_queue;
356     add_disk(z2ram_gendisk);
357     blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
358                                 z2_find, NULL, NULL);
359 
360     return 0;
361 
362 out_queue:
363     put_disk(z2ram_gendisk);
364 out_disk:
365     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
366 err:
367     return ret;
368 }
369 
370 static void __exit z2_exit(void)
371 {
372     int i, j;
373     blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), 256);
374     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
375     del_gendisk(z2ram_gendisk);
376     put_disk(z2ram_gendisk);
377     blk_cleanup_queue(z2_queue);
378 
379     if ( current_device != -1 )
380     {
381         i = 0;
382 
383         for ( j = 0 ; j < z2_count; j++ )
384         {
385             set_bit( i++, zorro_unused_z2ram ); 
386         }
387 
388         for ( j = 0 ; j < chip_count; j++ )
389         {
390             if ( z2ram_map[ i ] )
391             {
392                 amiga_chip_free( (void *) z2ram_map[ i++ ] );
393             }
394         }
395 
396         if ( z2ram_map != NULL )
397         {
398             kfree( z2ram_map );
399         }
400     }
401 
402     return;
403 } 
404 
405 module_init(z2_init);
406 module_exit(z2_exit);
407 MODULE_LICENSE("GPL");
408 
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