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