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#define Z2MINOR_COMBINED      (0)
46#define Z2MINOR_Z2ONLY        (1)
47#define Z2MINOR_CHIPONLY      (2)
48#define Z2MINOR_MEMLIST1      (4)
49#define Z2MINOR_MEMLIST2      (5)
50#define Z2MINOR_MEMLIST3      (6)
51#define Z2MINOR_MEMLIST4      (7)
52#define Z2MINOR_COUNT         (8)	/* Move this down when adding a new minor */
53
54#define Z2RAM_CHUNK1024       ( Z2RAM_CHUNKSIZE >> 10 )
55
56static DEFINE_MUTEX(z2ram_mutex);
57static u_long *z2ram_map = NULL;
58static u_long z2ram_size = 0;
59static int z2_count = 0;
60static int chip_count = 0;
61static int list_count = 0;
62static int current_device = -1;
63
64static DEFINE_SPINLOCK(z2ram_lock);
65
66static struct gendisk *z2ram_gendisk[Z2MINOR_COUNT];
67
68static blk_status_t z2_queue_rq(struct blk_mq_hw_ctx *hctx,
69				const struct blk_mq_queue_data *bd)
70{
71	struct request *req = bd->rq;
72	unsigned long start = blk_rq_pos(req) << 9;
73	unsigned long len = blk_rq_cur_bytes(req);
74
75	blk_mq_start_request(req);
76
77	if (start + len > z2ram_size) {
78		pr_err(DEVICE_NAME ": bad access: block=%llu, "
79		       "count=%u\n",
80		       (unsigned long long)blk_rq_pos(req),
81		       blk_rq_cur_sectors(req));
82		return BLK_STS_IOERR;
83	}
84
85	spin_lock_irq(&z2ram_lock);
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
103	spin_unlock_irq(&z2ram_lock);
104	blk_mq_end_request(req, BLK_STS_OK);
105	return BLK_STS_OK;
106}
107
108static void get_z2ram(void)
109{
110	int i;
111
112	for (i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++) {
113		if (test_bit(i, zorro_unused_z2ram)) {
114			z2_count++;
115			z2ram_map[z2ram_size++] =
116			    (unsigned long)ZTWO_VADDR(Z2RAM_START) +
117			    (i << Z2RAM_CHUNKSHIFT);
118			clear_bit(i, zorro_unused_z2ram);
119		}
120	}
121
122	return;
123}
124
125static void get_chipram(void)
126{
127
128	while (amiga_chip_avail() > (Z2RAM_CHUNKSIZE * 4)) {
129		chip_count++;
130		z2ram_map[z2ram_size] =
131		    (u_long) amiga_chip_alloc(Z2RAM_CHUNKSIZE, "z2ram");
132
133		if (z2ram_map[z2ram_size] == 0) {
134			break;
135		}
136
137		z2ram_size++;
138	}
139
140	return;
141}
142
143static int z2_open(struct gendisk *disk, blk_mode_t mode)
144{
145	int device = disk->first_minor;
146	int max_z2_map = (Z2RAM_SIZE / Z2RAM_CHUNKSIZE) * sizeof(z2ram_map[0]);
147	int max_chip_map = (amiga_chip_size / Z2RAM_CHUNKSIZE) *
148	    sizeof(z2ram_map[0]);
149	int rc = -ENOMEM;
150
151	mutex_lock(&z2ram_mutex);
152	if (current_device != -1 && current_device != device) {
153		rc = -EBUSY;
154		goto err_out;
155	}
156
157	if (current_device == -1) {
158		z2_count = 0;
159		chip_count = 0;
160		list_count = 0;
161		z2ram_size = 0;
162
163		/* Use a specific list entry. */
164		if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
165			int index = device - Z2MINOR_MEMLIST1 + 1;
166			unsigned long size, paddr, vaddr;
167
168			if (index >= m68k_realnum_memory) {
169				printk(KERN_ERR DEVICE_NAME
170				       ": no such entry in z2ram_map\n");
171				goto err_out;
172			}
173
174			paddr = m68k_memory[index].addr;
175			size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE - 1);
176
177#ifdef __powerpc__
178			/* FIXME: ioremap doesn't build correct memory tables. */
179			{
180				vfree(vmalloc(size));
181			}
182
183			vaddr = (unsigned long)ioremap_wt(paddr, size);
184
185#else
186			vaddr =
187			    (unsigned long)z_remap_nocache_nonser(paddr, size);
188#endif
189			z2ram_map =
190			    kmalloc_array(size / Z2RAM_CHUNKSIZE,
191					  sizeof(z2ram_map[0]), GFP_KERNEL);
192			if (z2ram_map == NULL) {
193				printk(KERN_ERR DEVICE_NAME
194				       ": cannot get mem for z2ram_map\n");
195				goto err_out;
196			}
197
198			while (size) {
199				z2ram_map[z2ram_size++] = vaddr;
200				size -= Z2RAM_CHUNKSIZE;
201				vaddr += Z2RAM_CHUNKSIZE;
202				list_count++;
203			}
204
205			if (z2ram_size != 0)
206				printk(KERN_INFO DEVICE_NAME
207				       ": using %iK List Entry %d Memory\n",
208				       list_count * Z2RAM_CHUNK1024, index);
209		} else
210			switch (device) {
211			case Z2MINOR_COMBINED:
212
213				z2ram_map =
214				    kmalloc(max_z2_map + max_chip_map,
215					    GFP_KERNEL);
216				if (z2ram_map == NULL) {
217					printk(KERN_ERR DEVICE_NAME
218					       ": cannot get mem for z2ram_map\n");
219					goto err_out;
220				}
221
222				get_z2ram();
223				get_chipram();
224
225				if (z2ram_size != 0)
226					printk(KERN_INFO DEVICE_NAME
227					       ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
228					       z2_count * Z2RAM_CHUNK1024,
229					       chip_count * Z2RAM_CHUNK1024,
230					       (z2_count +
231						chip_count) * Z2RAM_CHUNK1024);
232
233				break;
234
235			case Z2MINOR_Z2ONLY:
236				z2ram_map = kmalloc(max_z2_map, GFP_KERNEL);
237				if (!z2ram_map)
238					goto err_out;
239
240				get_z2ram();
241
242				if (z2ram_size != 0)
243					printk(KERN_INFO DEVICE_NAME
244					       ": using %iK of Zorro II RAM\n",
245					       z2_count * Z2RAM_CHUNK1024);
246
247				break;
248
249			case Z2MINOR_CHIPONLY:
250				z2ram_map = kmalloc(max_chip_map, GFP_KERNEL);
251				if (!z2ram_map)
252					goto err_out;
253
254				get_chipram();
255
256				if (z2ram_size != 0)
257					printk(KERN_INFO DEVICE_NAME
258					       ": using %iK Chip RAM\n",
259					       chip_count * Z2RAM_CHUNK1024);
260
261				break;
262
263			default:
264				rc = -ENODEV;
265				goto err_out;
266
267				break;
268			}
269
270		if (z2ram_size == 0) {
271			printk(KERN_NOTICE DEVICE_NAME
272			       ": no unused ZII/Chip RAM found\n");
273			goto err_out_kfree;
274		}
275
276		current_device = device;
277		z2ram_size <<= Z2RAM_CHUNKSHIFT;
278		set_capacity(z2ram_gendisk[device], z2ram_size >> 9);
279	}
280
281	mutex_unlock(&z2ram_mutex);
282	return 0;
283
284err_out_kfree:
285	kfree(z2ram_map);
286err_out:
287	mutex_unlock(&z2ram_mutex);
288	return rc;
289}
290
291static void z2_release(struct gendisk *disk)
292{
293	mutex_lock(&z2ram_mutex);
294	if (current_device == -1) {
295		mutex_unlock(&z2ram_mutex);
296		return;
297	}
298	mutex_unlock(&z2ram_mutex);
299	/*
300	 * FIXME: unmap memory
301	 */
302}
303
304static const struct block_device_operations z2_fops = {
305	.owner = THIS_MODULE,
306	.open = z2_open,
307	.release = z2_release,
308};
309
310static struct blk_mq_tag_set tag_set;
311
312static const struct blk_mq_ops z2_mq_ops = {
313	.queue_rq = z2_queue_rq,
314};
315
316static int z2ram_register_disk(int minor)
317{
318	struct gendisk *disk;
319	int err;
320
321	disk = blk_mq_alloc_disk(&tag_set, NULL, NULL);
322	if (IS_ERR(disk))
323		return PTR_ERR(disk);
324
325	disk->major = Z2RAM_MAJOR;
326	disk->first_minor = minor;
327	disk->minors = 1;
328	disk->flags |= GENHD_FL_NO_PART;
329	disk->fops = &z2_fops;
330	if (minor)
331		sprintf(disk->disk_name, "z2ram%d", minor);
332	else
333		sprintf(disk->disk_name, "z2ram");
334
335	z2ram_gendisk[minor] = disk;
336	err = add_disk(disk);
337	if (err)
338		put_disk(disk);
339	return err;
340}
341
342static int __init z2_init(void)
343{
344	int ret, i;
345
346	if (!MACH_IS_AMIGA)
347		return -ENODEV;
348
349	if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
350		return -EBUSY;
351
352	tag_set.ops = &z2_mq_ops;
353	tag_set.nr_hw_queues = 1;
354	tag_set.nr_maps = 1;
355	tag_set.queue_depth = 16;
356	tag_set.numa_node = NUMA_NO_NODE;
357	tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
358	ret = blk_mq_alloc_tag_set(&tag_set);
359	if (ret)
360		goto out_unregister_blkdev;
361
362	for (i = 0; i < Z2MINOR_COUNT; i++) {
363		ret = z2ram_register_disk(i);
364		if (ret && i == 0)
365			goto out_free_tagset;
366	}
367
368	return 0;
369
370out_free_tagset:
371	blk_mq_free_tag_set(&tag_set);
372out_unregister_blkdev:
373	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
374	return ret;
375}
376
377static void __exit z2_exit(void)
378{
379	int i, j;
380
381	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
382
383	for (i = 0; i < Z2MINOR_COUNT; i++) {
384		del_gendisk(z2ram_gendisk[i]);
385		put_disk(z2ram_gendisk[i]);
386	}
387	blk_mq_free_tag_set(&tag_set);
388
389	if (current_device != -1) {
390		i = 0;
391
392		for (j = 0; j < z2_count; j++) {
393			set_bit(i++, zorro_unused_z2ram);
394		}
395
396		for (j = 0; j < chip_count; j++) {
397			if (z2ram_map[i]) {
398				amiga_chip_free((void *)z2ram_map[i++]);
399			}
400		}
401
402		if (z2ram_map != NULL) {
403			kfree(z2ram_map);
404		}
405	}
406
407	return;
408}
409
410module_init(z2_init);
411module_exit(z2_exit);
412MODULE_LICENSE("GPL");
413