xref: /openbmc/linux/drivers/block/z2ram.c (revision 11c416e3)
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 #include <linux/pgtable.h>
39 
40 #include <asm/setup.h>
41 #include <asm/amigahw.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_wt(paddr, size);
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 static struct blk_mq_tag_set tag_set;
341 
342 static const struct blk_mq_ops z2_mq_ops = {
343 	.queue_rq	= z2_queue_rq,
344 };
345 
346 static int __init
347 z2_init(void)
348 {
349     int ret;
350 
351     if (!MACH_IS_AMIGA)
352 	return -ENODEV;
353 
354     ret = -EBUSY;
355     if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
356 	goto err;
357 
358     ret = -ENOMEM;
359     z2ram_gendisk = alloc_disk(1);
360     if (!z2ram_gendisk)
361 	goto out_disk;
362 
363     z2_queue = blk_mq_init_sq_queue(&tag_set, &z2_mq_ops, 16,
364 					BLK_MQ_F_SHOULD_MERGE);
365     if (IS_ERR(z2_queue)) {
366 	ret = PTR_ERR(z2_queue);
367 	z2_queue = NULL;
368 	goto out_queue;
369     }
370 
371     z2ram_gendisk->major = Z2RAM_MAJOR;
372     z2ram_gendisk->first_minor = 0;
373     z2ram_gendisk->fops = &z2_fops;
374     sprintf(z2ram_gendisk->disk_name, "z2ram");
375 
376     z2ram_gendisk->queue = z2_queue;
377     add_disk(z2ram_gendisk);
378     blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
379 				z2_find, NULL, NULL);
380 
381     return 0;
382 
383 out_queue:
384     put_disk(z2ram_gendisk);
385 out_disk:
386     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
387 err:
388     return ret;
389 }
390 
391 static void __exit z2_exit(void)
392 {
393     int i, j;
394     blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
395     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
396     del_gendisk(z2ram_gendisk);
397     put_disk(z2ram_gendisk);
398     blk_cleanup_queue(z2_queue);
399     blk_mq_free_tag_set(&tag_set);
400 
401     if ( current_device != -1 )
402     {
403 	i = 0;
404 
405 	for ( j = 0 ; j < z2_count; j++ )
406 	{
407 	    set_bit( i++, zorro_unused_z2ram );
408 	}
409 
410 	for ( j = 0 ; j < chip_count; j++ )
411 	{
412 	    if ( z2ram_map[ i ] )
413 	    {
414 		amiga_chip_free( (void *) z2ram_map[ i++ ] );
415 	    }
416 	}
417 
418 	if ( z2ram_map != NULL )
419 	{
420 	    kfree( z2ram_map );
421 	}
422     }
423 
424     return;
425 }
426 
427 module_init(z2_init);
428 module_exit(z2_exit);
429 MODULE_LICENSE("GPL");
430