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z2ram.c
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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 ([email protected])
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 #include <linux/mutex.h>
37 #include <linux/slab.h>
38 
39 #include <asm/setup.h>
40 #include <asm/amigahw.h>
41 #include <asm/pgtable.h>
42 
43 #include <linux/zorro.h>
44 
45 
46 extern int m68k_realnum_memory;
47 extern struct mem_info m68k_memory[NUM_MEMINFO];
48 
49 #define Z2MINOR_COMBINED (0)
50 #define Z2MINOR_Z2ONLY (1)
51 #define Z2MINOR_CHIPONLY (2)
52 #define Z2MINOR_MEMLIST1 (4)
53 #define Z2MINOR_MEMLIST2 (5)
54 #define Z2MINOR_MEMLIST3 (6)
55 #define Z2MINOR_MEMLIST4 (7)
56 #define Z2MINOR_COUNT (8) /* Move this down when adding a new minor */
57 
58 #define Z2RAM_CHUNK1024 ( Z2RAM_CHUNKSIZE >> 10 )
59 
60 static DEFINE_MUTEX(z2ram_mutex);
61 static u_long *z2ram_map = NULL;
62 static u_long z2ram_size = 0;
63 static int z2_count = 0;
64 static int chip_count = 0;
65 static int list_count = 0;
66 static int current_device = -1;
67 
68 static DEFINE_SPINLOCK(z2ram_lock);
69 
70 static struct gendisk *z2ram_gendisk;
71 
72 static void do_z2_request(struct request_queue *q)
73 {
74  struct request *req;
75 
76  req = blk_fetch_request(q);
77  while (req) {
78  unsigned long start = blk_rq_pos(req) << 9;
79  unsigned long len = blk_rq_cur_bytes(req);
80  int err = 0;
81 
82  if (start + len > z2ram_size) {
83  pr_err(DEVICE_NAME ": bad access: block=%llu, "
84  "count=%u\n",
85  (unsigned long long)blk_rq_pos(req),
86  blk_rq_cur_sectors(req));
87  err = -EIO;
88  goto done;
89  }
90  while (len) {
91  unsigned long addr = start & Z2RAM_CHUNKMASK;
92  unsigned long size = Z2RAM_CHUNKSIZE - addr;
93  if (len < size)
94  size = len;
95  addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
96  if (rq_data_dir(req) == READ)
97  memcpy(req->buffer, (char *)addr, size);
98  else
99  memcpy((char *)addr, req->buffer, size);
100  start += size;
101  len -= size;
102  }
103  done:
104  if (!__blk_end_request_cur(req, err))
105  req = blk_fetch_request(q);
106  }
107 }
108 
109 static void
110 get_z2ram( void )
111 {
112  int i;
113 
114  for ( i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++ )
115  {
116  if ( test_bit( i, zorro_unused_z2ram ) )
117  {
118  z2_count++;
119  z2ram_map[ z2ram_size++ ] =
120  ZTWO_VADDR( Z2RAM_START ) + ( i << Z2RAM_CHUNKSHIFT );
121  clear_bit( i, zorro_unused_z2ram );
122  }
123  }
124 
125  return;
126 }
127 
128 static void
129 get_chipram( void )
130 {
131 
132  while ( amiga_chip_avail() > ( Z2RAM_CHUNKSIZE * 4 ) )
133  {
134  chip_count++;
135  z2ram_map[ z2ram_size ] =
136  (u_long)amiga_chip_alloc( Z2RAM_CHUNKSIZE, "z2ram" );
137 
138  if ( z2ram_map[ z2ram_size ] == 0 )
139  {
140  break;
141  }
142 
143  z2ram_size++;
144  }
145 
146  return;
147 }
148 
149 static int z2_open(struct block_device *bdev, fmode_t mode)
150 {
151  int device;
152  int max_z2_map = ( Z2RAM_SIZE / Z2RAM_CHUNKSIZE ) *
153  sizeof( z2ram_map[0] );
154  int max_chip_map = ( amiga_chip_size / Z2RAM_CHUNKSIZE ) *
155  sizeof( z2ram_map[0] );
156  int rc = -ENOMEM;
157 
158  device = MINOR(bdev->bd_dev);
159 
160  mutex_lock(&z2ram_mutex);
161  if ( current_device != -1 && current_device != device )
162  {
163  rc = -EBUSY;
164  goto err_out;
165  }
166 
167  if ( current_device == -1 )
168  {
169  z2_count = 0;
170  chip_count = 0;
171  list_count = 0;
172  z2ram_size = 0;
173 
174  /* Use a specific list entry. */
175  if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
176  int index = device - Z2MINOR_MEMLIST1 + 1;
177  unsigned long size, paddr, vaddr;
178 
179  if (index >= m68k_realnum_memory) {
180  printk( KERN_ERR DEVICE_NAME
181  ": no such entry in z2ram_map\n" );
182  goto err_out;
183  }
184 
185  paddr = m68k_memory[index].addr;
186  size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE-1);
187 
188 #ifdef __powerpc__
189  /* FIXME: ioremap doesn't build correct memory tables. */
190  {
191  vfree(vmalloc (size));
192  }
193 
194  vaddr = (unsigned long) __ioremap (paddr, size,
195  _PAGE_WRITETHRU);
196 
197 #else
198  vaddr = (unsigned long)z_remap_nocache_nonser(paddr, size);
199 #endif
200  z2ram_map =
201  kmalloc((size/Z2RAM_CHUNKSIZE)*sizeof(z2ram_map[0]),
202  GFP_KERNEL);
203  if ( z2ram_map == NULL )
204  {
205  printk( KERN_ERR DEVICE_NAME
206  ": cannot get mem for z2ram_map\n" );
207  goto err_out;
208  }
209 
210  while (size) {
211  z2ram_map[ z2ram_size++ ] = vaddr;
212  size -= Z2RAM_CHUNKSIZE;
213  vaddr += Z2RAM_CHUNKSIZE;
214  list_count++;
215  }
216 
217  if ( z2ram_size != 0 )
218  printk( KERN_INFO DEVICE_NAME
219  ": using %iK List Entry %d Memory\n",
220  list_count * Z2RAM_CHUNK1024, index );
221  } else
222 
223  switch ( device )
224  {
225  case Z2MINOR_COMBINED:
226 
227  z2ram_map = kmalloc( max_z2_map + max_chip_map, GFP_KERNEL );
228  if ( z2ram_map == NULL )
229  {
230  printk( KERN_ERR DEVICE_NAME
231  ": cannot get mem for z2ram_map\n" );
232  goto err_out;
233  }
234 
235  get_z2ram();
236  get_chipram();
237 
238  if ( z2ram_size != 0 )
239  printk( KERN_INFO DEVICE_NAME
240  ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
241  z2_count * Z2RAM_CHUNK1024,
242  chip_count * Z2RAM_CHUNK1024,
243  ( z2_count + chip_count ) * Z2RAM_CHUNK1024 );
244 
245  break;
246 
247  case Z2MINOR_Z2ONLY:
248  z2ram_map = kmalloc( max_z2_map, GFP_KERNEL );
249  if ( z2ram_map == NULL )
250  {
251  printk( KERN_ERR DEVICE_NAME
252  ": cannot get mem for z2ram_map\n" );
253  goto err_out;
254  }
255 
256  get_z2ram();
257 
258  if ( z2ram_size != 0 )
259  printk( KERN_INFO DEVICE_NAME
260  ": using %iK of Zorro II RAM\n",
261  z2_count * Z2RAM_CHUNK1024 );
262 
263  break;
264 
265  case Z2MINOR_CHIPONLY:
266  z2ram_map = kmalloc( max_chip_map, GFP_KERNEL );
267  if ( z2ram_map == NULL )
268  {
269  printk( KERN_ERR DEVICE_NAME
270  ": cannot get mem for z2ram_map\n" );
271  goto err_out;
272  }
273 
274  get_chipram();
275 
276  if ( z2ram_size != 0 )
277  printk( KERN_INFO DEVICE_NAME
278  ": using %iK Chip RAM\n",
279  chip_count * Z2RAM_CHUNK1024 );
280 
281  break;
282 
283  default:
284  rc = -ENODEV;
285  goto err_out;
286 
287  break;
288  }
289 
290  if ( z2ram_size == 0 )
291  {
292  printk( KERN_NOTICE DEVICE_NAME
293  ": no unused ZII/Chip RAM found\n" );
294  goto err_out_kfree;
295  }
296 
297  current_device = device;
298  z2ram_size <<= Z2RAM_CHUNKSHIFT;
299  set_capacity(z2ram_gendisk, z2ram_size >> 9);
300  }
301 
302  mutex_unlock(&z2ram_mutex);
303  return 0;
304 
305 err_out_kfree:
306  kfree(z2ram_map);
307 err_out:
308  mutex_unlock(&z2ram_mutex);
309  return rc;
310 }
311 
312 static int
313 z2_release(struct gendisk *disk, fmode_t mode)
314 {
315  mutex_lock(&z2ram_mutex);
316  if ( current_device == -1 ) {
317  mutex_unlock(&z2ram_mutex);
318  return 0;
319  }
320  mutex_unlock(&z2ram_mutex);
321  /*
322  * FIXME: unmap memory
323  */
324 
325  return 0;
326 }
327 
328 static const struct block_device_operations z2_fops =
329 {
330  .owner = THIS_MODULE,
331  .open = z2_open,
332  .release = z2_release,
333 };
334 
335 static struct kobject *z2_find(dev_t dev, int *part, void *data)
336 {
337  *part = 0;
338  return get_disk(z2ram_gendisk);
339 }
340 
341 static struct request_queue *z2_queue;
342 
343 static int __init
344 z2_init(void)
345 {
346  int ret;
347 
348  if (!MACH_IS_AMIGA)
349  return -ENODEV;
350 
351  ret = -EBUSY;
352  if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
353  goto err;
354 
355  ret = -ENOMEM;
356  z2ram_gendisk = alloc_disk(1);
357  if (!z2ram_gendisk)
358  goto out_disk;
359 
360  z2_queue = blk_init_queue(do_z2_request, &z2ram_lock);
361  if (!z2_queue)
362  goto out_queue;
363 
364  z2ram_gendisk->major = Z2RAM_MAJOR;
365  z2ram_gendisk->first_minor = 0;
366  z2ram_gendisk->fops = &z2_fops;
367  sprintf(z2ram_gendisk->disk_name, "z2ram");
368 
369  z2ram_gendisk->queue = z2_queue;
370  add_disk(z2ram_gendisk);
371  blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
372  z2_find, NULL, NULL);
373 
374  return 0;
375 
376 out_queue:
377  put_disk(z2ram_gendisk);
378 out_disk:
379  unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
380 err:
381  return ret;
382 }
383 
384 static void __exit z2_exit(void)
385 {
386  int i, j;
387  blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
388  unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
389  del_gendisk(z2ram_gendisk);
390  put_disk(z2ram_gendisk);
391  blk_cleanup_queue(z2_queue);
392 
393  if ( current_device != -1 )
394  {
395  i = 0;
396 
397  for ( j = 0 ; j < z2_count; j++ )
398  {
399  set_bit( i++, zorro_unused_z2ram );
400  }
401 
402  for ( j = 0 ; j < chip_count; j++ )
403  {
404  if ( z2ram_map[ i ] )
405  {
406  amiga_chip_free( (void *) z2ram_map[ i++ ] );
407  }
408  }
409 
410  if ( z2ram_map != NULL )
411  {
412  kfree( z2ram_map );
413  }
414  }
415 
416  return;
417 }
418 
419 module_init(z2_init);
420 module_exit(z2_exit);
421 MODULE_LICENSE("GPL");
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