xref: /kernel/linux/linux-5.10/drivers/block/z2ram.c (revision 8c2ecf20)
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
57static DEFINE_MUTEX(z2ram_mutex);
58static u_long *z2ram_map    = NULL;
59static u_long z2ram_size    = 0;
60static int z2_count         = 0;
61static int chip_count       = 0;
62static int list_count       = 0;
63static int current_device   = -1;
64
65static DEFINE_SPINLOCK(z2ram_lock);
66
67static struct gendisk *z2ram_gendisk;
68
69static 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
109static void
110get_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
128static void
129get_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
149static 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
305err_out_kfree:
306    kfree(z2ram_map);
307err_out:
308    mutex_unlock(&z2ram_mutex);
309    return rc;
310}
311
312static void
313z2_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
326static const struct block_device_operations z2_fops =
327{
328	.owner		= THIS_MODULE,
329	.open		= z2_open,
330	.release	= z2_release,
331};
332
333static 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
339static struct request_queue *z2_queue;
340static struct blk_mq_tag_set tag_set;
341
342static const struct blk_mq_ops z2_mq_ops = {
343	.queue_rq	= z2_queue_rq,
344};
345
346static int __init
347z2_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
383out_queue:
384    put_disk(z2ram_gendisk);
385out_disk:
386    unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
387err:
388    return ret;
389}
390
391static 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
427module_init(z2_init);
428module_exit(z2_exit);
429MODULE_LICENSE("GPL");
430