xref: /openbmc/linux/drivers/block/z2ram.c (revision a17922de)
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_array(size / Z2RAM_CHUNKSIZE,
201                                       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 void
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;
319     }
320     mutex_unlock(&z2ram_mutex);
321     /*
322      * FIXME: unmap memory
323      */
324 }
325 
326 static const struct block_device_operations z2_fops =
327 {
328 	.owner		= THIS_MODULE,
329 	.open		= z2_open,
330 	.release	= z2_release,
331 };
332 
333 static struct kobject *z2_find(dev_t dev, int *part, void *data)
334 {
335 	*part = 0;
336 	return get_disk_and_module(z2ram_gendisk);
337 }
338 
339 static struct request_queue *z2_queue;
340 
341 static int __init
342 z2_init(void)
343 {
344     int ret;
345 
346     if (!MACH_IS_AMIGA)
347 	return -ENODEV;
348 
349     ret = -EBUSY;
350     if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
351 	goto err;
352 
353     ret = -ENOMEM;
354     z2ram_gendisk = alloc_disk(1);
355     if (!z2ram_gendisk)
356 	goto out_disk;
357 
358     z2_queue = blk_init_queue(do_z2_request, &z2ram_lock);
359     if (!z2_queue)
360 	goto out_queue;
361 
362     z2ram_gendisk->major = Z2RAM_MAJOR;
363     z2ram_gendisk->first_minor = 0;
364     z2ram_gendisk->fops = &z2_fops;
365     sprintf(z2ram_gendisk->disk_name, "z2ram");
366 
367     z2ram_gendisk->queue = z2_queue;
368     add_disk(z2ram_gendisk);
369     blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
370 				z2_find, NULL, NULL);
371 
372     return 0;
373 
374 out_queue:
375     put_disk(z2ram_gendisk);
376 out_disk:
377     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
378 err:
379     return ret;
380 }
381 
382 static void __exit z2_exit(void)
383 {
384     int i, j;
385     blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
386     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
387     del_gendisk(z2ram_gendisk);
388     put_disk(z2ram_gendisk);
389     blk_cleanup_queue(z2_queue);
390 
391     if ( current_device != -1 )
392     {
393 	i = 0;
394 
395 	for ( j = 0 ; j < z2_count; j++ )
396 	{
397 	    set_bit( i++, zorro_unused_z2ram );
398 	}
399 
400 	for ( j = 0 ; j < chip_count; j++ )
401 	{
402 	    if ( z2ram_map[ i ] )
403 	    {
404 		amiga_chip_free( (void *) z2ram_map[ i++ ] );
405 	    }
406 	}
407 
408 	if ( z2ram_map != NULL )
409 	{
410 	    kfree( z2ram_map );
411 	}
412     }
413 
414     return;
415 }
416 
417 module_init(z2_init);
418 module_exit(z2_exit);
419 MODULE_LICENSE("GPL");
420