xref: /openbmc/linux/drivers/block/z2ram.c (revision 483eb062)
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 		int err = 0;
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 = -EIO;
85 			goto done;
86 		}
87 		while (len) {
88 			unsigned long addr = start & Z2RAM_CHUNKMASK;
89 			unsigned long size = Z2RAM_CHUNKSIZE - addr;
90 			if (len < size)
91 				size = len;
92 			addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
93 			if (rq_data_dir(req) == READ)
94 				memcpy(req->buffer, (char *)addr, size);
95 			else
96 				memcpy((char *)addr, req->buffer, size);
97 			start += size;
98 			len -= size;
99 		}
100 	done:
101 		if (!__blk_end_request_cur(req, err))
102 			req = blk_fetch_request(q);
103 	}
104 }
105 
106 static void
107 get_z2ram( void )
108 {
109     int i;
110 
111     for ( i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++ )
112     {
113 	if ( test_bit( i, zorro_unused_z2ram ) )
114 	{
115 	    z2_count++;
116 	    z2ram_map[z2ram_size++] = (unsigned long)ZTWO_VADDR(Z2RAM_START) +
117 				      (i << Z2RAM_CHUNKSHIFT);
118 	    clear_bit( i, zorro_unused_z2ram );
119 	}
120     }
121 
122     return;
123 }
124 
125 static void
126 get_chipram( void )
127 {
128 
129     while ( amiga_chip_avail() > ( Z2RAM_CHUNKSIZE * 4 ) )
130     {
131 	chip_count++;
132 	z2ram_map[ z2ram_size ] =
133 	    (u_long)amiga_chip_alloc( Z2RAM_CHUNKSIZE, "z2ram" );
134 
135 	if ( z2ram_map[ z2ram_size ] == 0 )
136 	{
137 	    break;
138 	}
139 
140 	z2ram_size++;
141     }
142 
143     return;
144 }
145 
146 static int z2_open(struct block_device *bdev, fmode_t mode)
147 {
148     int device;
149     int max_z2_map = ( Z2RAM_SIZE / Z2RAM_CHUNKSIZE ) *
150 	sizeof( z2ram_map[0] );
151     int max_chip_map = ( amiga_chip_size / Z2RAM_CHUNKSIZE ) *
152 	sizeof( z2ram_map[0] );
153     int rc = -ENOMEM;
154 
155     device = MINOR(bdev->bd_dev);
156 
157     mutex_lock(&z2ram_mutex);
158     if ( current_device != -1 && current_device != device )
159     {
160 	rc = -EBUSY;
161 	goto err_out;
162     }
163 
164     if ( current_device == -1 )
165     {
166 	z2_count   = 0;
167 	chip_count = 0;
168 	list_count = 0;
169 	z2ram_size = 0;
170 
171 	/* Use a specific list entry. */
172 	if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
173 		int index = device - Z2MINOR_MEMLIST1 + 1;
174 		unsigned long size, paddr, vaddr;
175 
176 		if (index >= m68k_realnum_memory) {
177 			printk( KERN_ERR DEVICE_NAME
178 				": no such entry in z2ram_map\n" );
179 		        goto err_out;
180 		}
181 
182 		paddr = m68k_memory[index].addr;
183 		size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE-1);
184 
185 #ifdef __powerpc__
186 		/* FIXME: ioremap doesn't build correct memory tables. */
187 		{
188 			vfree(vmalloc (size));
189 		}
190 
191 		vaddr = (unsigned long) __ioremap (paddr, size,
192 						   _PAGE_WRITETHRU);
193 
194 #else
195 		vaddr = (unsigned long)z_remap_nocache_nonser(paddr, size);
196 #endif
197 		z2ram_map =
198 			kmalloc((size/Z2RAM_CHUNKSIZE)*sizeof(z2ram_map[0]),
199 				GFP_KERNEL);
200 		if ( z2ram_map == NULL )
201 		{
202 		    printk( KERN_ERR DEVICE_NAME
203 			": cannot get mem for z2ram_map\n" );
204 		    goto err_out;
205 		}
206 
207 		while (size) {
208 			z2ram_map[ z2ram_size++ ] = vaddr;
209 			size -= Z2RAM_CHUNKSIZE;
210 			vaddr += Z2RAM_CHUNKSIZE;
211 			list_count++;
212 		}
213 
214 		if ( z2ram_size != 0 )
215 		    printk( KERN_INFO DEVICE_NAME
216 			": using %iK List Entry %d Memory\n",
217 			list_count * Z2RAM_CHUNK1024, index );
218 	} else
219 
220 	switch ( device )
221 	{
222 	    case Z2MINOR_COMBINED:
223 
224 		z2ram_map = kmalloc( max_z2_map + max_chip_map, GFP_KERNEL );
225 		if ( z2ram_map == NULL )
226 		{
227 		    printk( KERN_ERR DEVICE_NAME
228 			": cannot get mem for z2ram_map\n" );
229 		    goto err_out;
230 		}
231 
232 		get_z2ram();
233 		get_chipram();
234 
235 		if ( z2ram_size != 0 )
236 		    printk( KERN_INFO DEVICE_NAME
237 			": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
238 			z2_count * Z2RAM_CHUNK1024,
239 			chip_count * Z2RAM_CHUNK1024,
240 			( z2_count + chip_count ) * Z2RAM_CHUNK1024 );
241 
242 	    break;
243 
244     	    case Z2MINOR_Z2ONLY:
245 		z2ram_map = kmalloc( max_z2_map, GFP_KERNEL );
246 		if ( z2ram_map == NULL )
247 		{
248 		    printk( KERN_ERR DEVICE_NAME
249 			": cannot get mem for z2ram_map\n" );
250 		    goto err_out;
251 		}
252 
253 		get_z2ram();
254 
255 		if ( z2ram_size != 0 )
256 		    printk( KERN_INFO DEVICE_NAME
257 			": using %iK of Zorro II RAM\n",
258 			z2_count * Z2RAM_CHUNK1024 );
259 
260 	    break;
261 
262 	    case Z2MINOR_CHIPONLY:
263 		z2ram_map = kmalloc( max_chip_map, GFP_KERNEL );
264 		if ( z2ram_map == NULL )
265 		{
266 		    printk( KERN_ERR DEVICE_NAME
267 			": cannot get mem for z2ram_map\n" );
268 		    goto err_out;
269 		}
270 
271 		get_chipram();
272 
273 		if ( z2ram_size != 0 )
274 		    printk( KERN_INFO DEVICE_NAME
275 			": using %iK Chip RAM\n",
276 			chip_count * Z2RAM_CHUNK1024 );
277 
278 	    break;
279 
280 	    default:
281 		rc = -ENODEV;
282 		goto err_out;
283 
284 	    break;
285 	}
286 
287 	if ( z2ram_size == 0 )
288 	{
289 	    printk( KERN_NOTICE DEVICE_NAME
290 		": no unused ZII/Chip RAM found\n" );
291 	    goto err_out_kfree;
292 	}
293 
294 	current_device = device;
295 	z2ram_size <<= Z2RAM_CHUNKSHIFT;
296 	set_capacity(z2ram_gendisk, z2ram_size >> 9);
297     }
298 
299     mutex_unlock(&z2ram_mutex);
300     return 0;
301 
302 err_out_kfree:
303     kfree(z2ram_map);
304 err_out:
305     mutex_unlock(&z2ram_mutex);
306     return rc;
307 }
308 
309 static void
310 z2_release(struct gendisk *disk, fmode_t mode)
311 {
312     mutex_lock(&z2ram_mutex);
313     if ( current_device == -1 ) {
314     	mutex_unlock(&z2ram_mutex);
315     	return;
316     }
317     mutex_unlock(&z2ram_mutex);
318     /*
319      * FIXME: unmap memory
320      */
321 }
322 
323 static const struct block_device_operations z2_fops =
324 {
325 	.owner		= THIS_MODULE,
326 	.open		= z2_open,
327 	.release	= z2_release,
328 };
329 
330 static struct kobject *z2_find(dev_t dev, int *part, void *data)
331 {
332 	*part = 0;
333 	return get_disk(z2ram_gendisk);
334 }
335 
336 static struct request_queue *z2_queue;
337 
338 static int __init
339 z2_init(void)
340 {
341     int ret;
342 
343     if (!MACH_IS_AMIGA)
344 	return -ENODEV;
345 
346     ret = -EBUSY;
347     if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
348 	goto err;
349 
350     ret = -ENOMEM;
351     z2ram_gendisk = alloc_disk(1);
352     if (!z2ram_gendisk)
353 	goto out_disk;
354 
355     z2_queue = blk_init_queue(do_z2_request, &z2ram_lock);
356     if (!z2_queue)
357 	goto out_queue;
358 
359     z2ram_gendisk->major = Z2RAM_MAJOR;
360     z2ram_gendisk->first_minor = 0;
361     z2ram_gendisk->fops = &z2_fops;
362     sprintf(z2ram_gendisk->disk_name, "z2ram");
363 
364     z2ram_gendisk->queue = z2_queue;
365     add_disk(z2ram_gendisk);
366     blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
367 				z2_find, NULL, NULL);
368 
369     return 0;
370 
371 out_queue:
372     put_disk(z2ram_gendisk);
373 out_disk:
374     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
375 err:
376     return ret;
377 }
378 
379 static void __exit z2_exit(void)
380 {
381     int i, j;
382     blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
383     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
384     del_gendisk(z2ram_gendisk);
385     put_disk(z2ram_gendisk);
386     blk_cleanup_queue(z2_queue);
387 
388     if ( current_device != -1 )
389     {
390 	i = 0;
391 
392 	for ( j = 0 ; j < z2_count; j++ )
393 	{
394 	    set_bit( i++, zorro_unused_z2ram );
395 	}
396 
397 	for ( j = 0 ; j < chip_count; j++ )
398 	{
399 	    if ( z2ram_map[ i ] )
400 	    {
401 		amiga_chip_free( (void *) z2ram_map[ i++ ] );
402 	    }
403 	}
404 
405 	if ( z2ram_map != NULL )
406 	{
407 	    kfree( z2ram_map );
408 	}
409     }
410 
411     return;
412 }
413 
414 module_init(z2_init);
415 module_exit(z2_exit);
416 MODULE_LICENSE("GPL");
417