xref: /linux/drivers/block/z2ram.c (revision b1d29ba82cf2bc784f4c963ddd6a2cf29e229b33)
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/blk-mq.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 blk_status_t z2_queue_rq(struct blk_mq_hw_ctx *hctx,
70 				const struct blk_mq_queue_data *bd)
71 {
72 	struct request *req = bd->rq;
73 	unsigned long start = blk_rq_pos(req) << 9;
74 	unsigned long len  = blk_rq_cur_bytes(req);
75 
76 	blk_mq_start_request(req);
77 
78 	if (start + len > z2ram_size) {
79 		pr_err(DEVICE_NAME ": bad access: block=%llu, "
80 		       "count=%u\n",
81 		       (unsigned long long)blk_rq_pos(req),
82 		       blk_rq_cur_sectors(req));
83 		return BLK_STS_IOERR;
84 	}
85 
86 	spin_lock_irq(&z2ram_lock);
87 
88 	while (len) {
89 		unsigned long addr = start & Z2RAM_CHUNKMASK;
90 		unsigned long size = Z2RAM_CHUNKSIZE - addr;
91 		void *buffer = bio_data(req->bio);
92 
93 		if (len < size)
94 			size = len;
95 		addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
96 		if (rq_data_dir(req) == READ)
97 			memcpy(buffer, (char *)addr, size);
98 		else
99 			memcpy((char *)addr, buffer, size);
100 		start += size;
101 		len -= size;
102 	}
103 
104 	spin_unlock_irq(&z2ram_lock);
105 	blk_mq_end_request(req, BLK_STS_OK);
106 	return BLK_STS_OK;
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++] = (unsigned long)ZTWO_VADDR(Z2RAM_START) +
120 				      (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_array(size / Z2RAM_CHUNKSIZE,
202                                       sizeof(z2ram_map[0]),
203                                       GFP_KERNEL);
204 		if ( z2ram_map == NULL )
205 		{
206 		    printk( KERN_ERR DEVICE_NAME
207 			": cannot get mem for z2ram_map\n" );
208 		    goto err_out;
209 		}
210 
211 		while (size) {
212 			z2ram_map[ z2ram_size++ ] = vaddr;
213 			size -= Z2RAM_CHUNKSIZE;
214 			vaddr += Z2RAM_CHUNKSIZE;
215 			list_count++;
216 		}
217 
218 		if ( z2ram_size != 0 )
219 		    printk( KERN_INFO DEVICE_NAME
220 			": using %iK List Entry %d Memory\n",
221 			list_count * Z2RAM_CHUNK1024, index );
222 	} else
223 
224 	switch ( device )
225 	{
226 	    case Z2MINOR_COMBINED:
227 
228 		z2ram_map = kmalloc( max_z2_map + max_chip_map, GFP_KERNEL );
229 		if ( z2ram_map == NULL )
230 		{
231 		    printk( KERN_ERR DEVICE_NAME
232 			": cannot get mem for z2ram_map\n" );
233 		    goto err_out;
234 		}
235 
236 		get_z2ram();
237 		get_chipram();
238 
239 		if ( z2ram_size != 0 )
240 		    printk( KERN_INFO DEVICE_NAME
241 			": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
242 			z2_count * Z2RAM_CHUNK1024,
243 			chip_count * Z2RAM_CHUNK1024,
244 			( z2_count + chip_count ) * Z2RAM_CHUNK1024 );
245 
246 	    break;
247 
248     	    case Z2MINOR_Z2ONLY:
249 		z2ram_map = kmalloc( max_z2_map, GFP_KERNEL );
250 		if ( z2ram_map == NULL )
251 		{
252 		    printk( KERN_ERR DEVICE_NAME
253 			": cannot get mem for z2ram_map\n" );
254 		    goto err_out;
255 		}
256 
257 		get_z2ram();
258 
259 		if ( z2ram_size != 0 )
260 		    printk( KERN_INFO DEVICE_NAME
261 			": using %iK of Zorro II RAM\n",
262 			z2_count * Z2RAM_CHUNK1024 );
263 
264 	    break;
265 
266 	    case Z2MINOR_CHIPONLY:
267 		z2ram_map = kmalloc( max_chip_map, GFP_KERNEL );
268 		if ( z2ram_map == NULL )
269 		{
270 		    printk( KERN_ERR DEVICE_NAME
271 			": cannot get mem for z2ram_map\n" );
272 		    goto err_out;
273 		}
274 
275 		get_chipram();
276 
277 		if ( z2ram_size != 0 )
278 		    printk( KERN_INFO DEVICE_NAME
279 			": using %iK Chip RAM\n",
280 			chip_count * Z2RAM_CHUNK1024 );
281 
282 	    break;
283 
284 	    default:
285 		rc = -ENODEV;
286 		goto err_out;
287 
288 	    break;
289 	}
290 
291 	if ( z2ram_size == 0 )
292 	{
293 	    printk( KERN_NOTICE DEVICE_NAME
294 		": no unused ZII/Chip RAM found\n" );
295 	    goto err_out_kfree;
296 	}
297 
298 	current_device = device;
299 	z2ram_size <<= Z2RAM_CHUNKSHIFT;
300 	set_capacity(z2ram_gendisk, z2ram_size >> 9);
301     }
302 
303     mutex_unlock(&z2ram_mutex);
304     return 0;
305 
306 err_out_kfree:
307     kfree(z2ram_map);
308 err_out:
309     mutex_unlock(&z2ram_mutex);
310     return rc;
311 }
312 
313 static void
314 z2_release(struct gendisk *disk, fmode_t mode)
315 {
316     mutex_lock(&z2ram_mutex);
317     if ( current_device == -1 ) {
318     	mutex_unlock(&z2ram_mutex);
319     	return;
320     }
321     mutex_unlock(&z2ram_mutex);
322     /*
323      * FIXME: unmap memory
324      */
325 }
326 
327 static const struct block_device_operations z2_fops =
328 {
329 	.owner		= THIS_MODULE,
330 	.open		= z2_open,
331 	.release	= z2_release,
332 };
333 
334 static struct kobject *z2_find(dev_t dev, int *part, void *data)
335 {
336 	*part = 0;
337 	return get_disk_and_module(z2ram_gendisk);
338 }
339 
340 static struct request_queue *z2_queue;
341 static struct blk_mq_tag_set tag_set;
342 
343 static const struct blk_mq_ops z2_mq_ops = {
344 	.queue_rq	= z2_queue_rq,
345 };
346 
347 static int __init
348 z2_init(void)
349 {
350     int ret;
351 
352     if (!MACH_IS_AMIGA)
353 	return -ENODEV;
354 
355     ret = -EBUSY;
356     if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
357 	goto err;
358 
359     ret = -ENOMEM;
360     z2ram_gendisk = alloc_disk(1);
361     if (!z2ram_gendisk)
362 	goto out_disk;
363 
364     z2_queue = blk_mq_init_sq_queue(&tag_set, &z2_mq_ops, 16,
365 					BLK_MQ_F_SHOULD_MERGE);
366     if (IS_ERR(z2_queue)) {
367 	ret = PTR_ERR(z2_queue);
368 	z2_queue = NULL;
369 	goto out_queue;
370     }
371 
372     z2ram_gendisk->major = Z2RAM_MAJOR;
373     z2ram_gendisk->first_minor = 0;
374     z2ram_gendisk->fops = &z2_fops;
375     sprintf(z2ram_gendisk->disk_name, "z2ram");
376 
377     z2ram_gendisk->queue = z2_queue;
378     add_disk(z2ram_gendisk);
379     blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
380 				z2_find, NULL, NULL);
381 
382     return 0;
383 
384 out_queue:
385     put_disk(z2ram_gendisk);
386 out_disk:
387     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
388 err:
389     return ret;
390 }
391 
392 static void __exit z2_exit(void)
393 {
394     int i, j;
395     blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
396     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
397     del_gendisk(z2ram_gendisk);
398     put_disk(z2ram_gendisk);
399     blk_cleanup_queue(z2_queue);
400     blk_mq_free_tag_set(&tag_set);
401 
402     if ( current_device != -1 )
403     {
404 	i = 0;
405 
406 	for ( j = 0 ; j < z2_count; j++ )
407 	{
408 	    set_bit( i++, zorro_unused_z2ram );
409 	}
410 
411 	for ( j = 0 ; j < chip_count; j++ )
412 	{
413 	    if ( z2ram_map[ i ] )
414 	    {
415 		amiga_chip_free( (void *) z2ram_map[ i++ ] );
416 	    }
417 	}
418 
419 	if ( z2ram_map != NULL )
420 	{
421 	    kfree( z2ram_map );
422 	}
423     }
424 
425     return;
426 }
427 
428 module_init(z2_init);
429 module_exit(z2_exit);
430 MODULE_LICENSE("GPL");
431