xref: /linux/drivers/block/z2ram.c (revision b48b89f9c189d24eb5e2b4a0ac067da5a24ee86d)
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 
56 static DEFINE_MUTEX(z2ram_mutex);
57 static u_long *z2ram_map = NULL;
58 static u_long z2ram_size = 0;
59 static int z2_count = 0;
60 static int chip_count = 0;
61 static int list_count = 0;
62 static int current_device = -1;
63 
64 static DEFINE_SPINLOCK(z2ram_lock);
65 
66 static struct gendisk *z2ram_gendisk[Z2MINOR_COUNT];
67 
68 static 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 
108 static 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 
125 static 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 
143 static int z2_open(struct block_device *bdev, fmode_t mode)
144 {
145 	int device;
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 	device = MINOR(bdev->bd_dev);
152 
153 	mutex_lock(&z2ram_mutex);
154 	if (current_device != -1 && current_device != device) {
155 		rc = -EBUSY;
156 		goto err_out;
157 	}
158 
159 	if (current_device == -1) {
160 		z2_count = 0;
161 		chip_count = 0;
162 		list_count = 0;
163 		z2ram_size = 0;
164 
165 		/* Use a specific list entry. */
166 		if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
167 			int index = device - Z2MINOR_MEMLIST1 + 1;
168 			unsigned long size, paddr, vaddr;
169 
170 			if (index >= m68k_realnum_memory) {
171 				printk(KERN_ERR DEVICE_NAME
172 				       ": no such entry in z2ram_map\n");
173 				goto err_out;
174 			}
175 
176 			paddr = m68k_memory[index].addr;
177 			size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE - 1);
178 
179 #ifdef __powerpc__
180 			/* FIXME: ioremap doesn't build correct memory tables. */
181 			{
182 				vfree(vmalloc(size));
183 			}
184 
185 			vaddr = (unsigned long)ioremap_wt(paddr, size);
186 
187 #else
188 			vaddr =
189 			    (unsigned long)z_remap_nocache_nonser(paddr, size);
190 #endif
191 			z2ram_map =
192 			    kmalloc_array(size / Z2RAM_CHUNKSIZE,
193 					  sizeof(z2ram_map[0]), GFP_KERNEL);
194 			if (z2ram_map == NULL) {
195 				printk(KERN_ERR DEVICE_NAME
196 				       ": cannot get mem for z2ram_map\n");
197 				goto err_out;
198 			}
199 
200 			while (size) {
201 				z2ram_map[z2ram_size++] = vaddr;
202 				size -= Z2RAM_CHUNKSIZE;
203 				vaddr += Z2RAM_CHUNKSIZE;
204 				list_count++;
205 			}
206 
207 			if (z2ram_size != 0)
208 				printk(KERN_INFO DEVICE_NAME
209 				       ": using %iK List Entry %d Memory\n",
210 				       list_count * Z2RAM_CHUNK1024, index);
211 		} else
212 			switch (device) {
213 			case Z2MINOR_COMBINED:
214 
215 				z2ram_map =
216 				    kmalloc(max_z2_map + max_chip_map,
217 					    GFP_KERNEL);
218 				if (z2ram_map == NULL) {
219 					printk(KERN_ERR DEVICE_NAME
220 					       ": cannot get mem for z2ram_map\n");
221 					goto err_out;
222 				}
223 
224 				get_z2ram();
225 				get_chipram();
226 
227 				if (z2ram_size != 0)
228 					printk(KERN_INFO DEVICE_NAME
229 					       ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
230 					       z2_count * Z2RAM_CHUNK1024,
231 					       chip_count * Z2RAM_CHUNK1024,
232 					       (z2_count +
233 						chip_count) * Z2RAM_CHUNK1024);
234 
235 				break;
236 
237 			case Z2MINOR_Z2ONLY:
238 				z2ram_map = kmalloc(max_z2_map, GFP_KERNEL);
239 				if (!z2ram_map)
240 					goto err_out;
241 
242 				get_z2ram();
243 
244 				if (z2ram_size != 0)
245 					printk(KERN_INFO DEVICE_NAME
246 					       ": using %iK of Zorro II RAM\n",
247 					       z2_count * Z2RAM_CHUNK1024);
248 
249 				break;
250 
251 			case Z2MINOR_CHIPONLY:
252 				z2ram_map = kmalloc(max_chip_map, GFP_KERNEL);
253 				if (!z2ram_map)
254 					goto err_out;
255 
256 				get_chipram();
257 
258 				if (z2ram_size != 0)
259 					printk(KERN_INFO DEVICE_NAME
260 					       ": using %iK Chip RAM\n",
261 					       chip_count * Z2RAM_CHUNK1024);
262 
263 				break;
264 
265 			default:
266 				rc = -ENODEV;
267 				goto err_out;
268 
269 				break;
270 			}
271 
272 		if (z2ram_size == 0) {
273 			printk(KERN_NOTICE DEVICE_NAME
274 			       ": no unused ZII/Chip RAM found\n");
275 			goto err_out_kfree;
276 		}
277 
278 		current_device = device;
279 		z2ram_size <<= Z2RAM_CHUNKSHIFT;
280 		set_capacity(z2ram_gendisk[device], z2ram_size >> 9);
281 	}
282 
283 	mutex_unlock(&z2ram_mutex);
284 	return 0;
285 
286 err_out_kfree:
287 	kfree(z2ram_map);
288 err_out:
289 	mutex_unlock(&z2ram_mutex);
290 	return rc;
291 }
292 
293 static void z2_release(struct gendisk *disk, fmode_t mode)
294 {
295 	mutex_lock(&z2ram_mutex);
296 	if (current_device == -1) {
297 		mutex_unlock(&z2ram_mutex);
298 		return;
299 	}
300 	mutex_unlock(&z2ram_mutex);
301 	/*
302 	 * FIXME: unmap memory
303 	 */
304 }
305 
306 static const struct block_device_operations z2_fops = {
307 	.owner = THIS_MODULE,
308 	.open = z2_open,
309 	.release = z2_release,
310 };
311 
312 static struct blk_mq_tag_set tag_set;
313 
314 static const struct blk_mq_ops z2_mq_ops = {
315 	.queue_rq = z2_queue_rq,
316 };
317 
318 static int z2ram_register_disk(int minor)
319 {
320 	struct gendisk *disk;
321 	int err;
322 
323 	disk = blk_mq_alloc_disk(&tag_set, NULL);
324 	if (IS_ERR(disk))
325 		return PTR_ERR(disk);
326 
327 	disk->major = Z2RAM_MAJOR;
328 	disk->first_minor = minor;
329 	disk->minors = 1;
330 	disk->flags |= GENHD_FL_NO_PART;
331 	disk->fops = &z2_fops;
332 	if (minor)
333 		sprintf(disk->disk_name, "z2ram%d", minor);
334 	else
335 		sprintf(disk->disk_name, "z2ram");
336 
337 	z2ram_gendisk[minor] = disk;
338 	err = add_disk(disk);
339 	if (err)
340 		put_disk(disk);
341 	return err;
342 }
343 
344 static int __init z2_init(void)
345 {
346 	int ret, i;
347 
348 	if (!MACH_IS_AMIGA)
349 		return -ENODEV;
350 
351 	if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
352 		return -EBUSY;
353 
354 	tag_set.ops = &z2_mq_ops;
355 	tag_set.nr_hw_queues = 1;
356 	tag_set.nr_maps = 1;
357 	tag_set.queue_depth = 16;
358 	tag_set.numa_node = NUMA_NO_NODE;
359 	tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
360 	ret = blk_mq_alloc_tag_set(&tag_set);
361 	if (ret)
362 		goto out_unregister_blkdev;
363 
364 	for (i = 0; i < Z2MINOR_COUNT; i++) {
365 		ret = z2ram_register_disk(i);
366 		if (ret && i == 0)
367 			goto out_free_tagset;
368 	}
369 
370 	return 0;
371 
372 out_free_tagset:
373 	blk_mq_free_tag_set(&tag_set);
374 out_unregister_blkdev:
375 	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
376 	return ret;
377 }
378 
379 static void __exit z2_exit(void)
380 {
381 	int i, j;
382 
383 	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
384 
385 	for (i = 0; i < Z2MINOR_COUNT; i++) {
386 		del_gendisk(z2ram_gendisk[i]);
387 		put_disk(z2ram_gendisk[i]);
388 	}
389 	blk_mq_free_tag_set(&tag_set);
390 
391 	if (current_device != -1) {
392 		i = 0;
393 
394 		for (j = 0; j < z2_count; j++) {
395 			set_bit(i++, zorro_unused_z2ram);
396 		}
397 
398 		for (j = 0; j < chip_count; j++) {
399 			if (z2ram_map[i]) {
400 				amiga_chip_free((void *)z2ram_map[i++]);
401 			}
402 		}
403 
404 		if (z2ram_map != NULL) {
405 			kfree(z2ram_map);
406 		}
407 	}
408 
409 	return;
410 }
411 
412 module_init(z2_init);
413 module_exit(z2_exit);
414 MODULE_LICENSE("GPL");
415