xref: /linux/drivers/block/z2ram.c (revision 32a92f8c89326985e05dce8b22d3f0aa07a3e1bd)
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 
z2_queue_rq(struct blk_mq_hw_ctx * hctx,const struct blk_mq_queue_data * bd)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 
get_z2ram(void)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 
get_chipram(void)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 
z2_open(struct gendisk * disk,blk_mode_t mode)143 static 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_objs(z2ram_map[0], size / Z2RAM_CHUNKSIZE);
191 			if (z2ram_map == NULL) {
192 				printk(KERN_ERR DEVICE_NAME
193 				       ": cannot get mem for z2ram_map\n");
194 				goto err_out;
195 			}
196 
197 			while (size) {
198 				z2ram_map[z2ram_size++] = vaddr;
199 				size -= Z2RAM_CHUNKSIZE;
200 				vaddr += Z2RAM_CHUNKSIZE;
201 				list_count++;
202 			}
203 
204 			if (z2ram_size != 0)
205 				printk(KERN_INFO DEVICE_NAME
206 				       ": using %iK List Entry %d Memory\n",
207 				       list_count * Z2RAM_CHUNK1024, index);
208 		} else
209 			switch (device) {
210 			case Z2MINOR_COMBINED:
211 
212 				z2ram_map =
213 				    kmalloc(max_z2_map + max_chip_map,
214 					    GFP_KERNEL);
215 				if (z2ram_map == NULL) {
216 					printk(KERN_ERR DEVICE_NAME
217 					       ": cannot get mem for z2ram_map\n");
218 					goto err_out;
219 				}
220 
221 				get_z2ram();
222 				get_chipram();
223 
224 				if (z2ram_size != 0)
225 					printk(KERN_INFO DEVICE_NAME
226 					       ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
227 					       z2_count * Z2RAM_CHUNK1024,
228 					       chip_count * Z2RAM_CHUNK1024,
229 					       (z2_count +
230 						chip_count) * Z2RAM_CHUNK1024);
231 
232 				break;
233 
234 			case Z2MINOR_Z2ONLY:
235 				z2ram_map = kmalloc(max_z2_map, GFP_KERNEL);
236 				if (!z2ram_map)
237 					goto err_out;
238 
239 				get_z2ram();
240 
241 				if (z2ram_size != 0)
242 					printk(KERN_INFO DEVICE_NAME
243 					       ": using %iK of Zorro II RAM\n",
244 					       z2_count * Z2RAM_CHUNK1024);
245 
246 				break;
247 
248 			case Z2MINOR_CHIPONLY:
249 				z2ram_map = kmalloc(max_chip_map, GFP_KERNEL);
250 				if (!z2ram_map)
251 					goto err_out;
252 
253 				get_chipram();
254 
255 				if (z2ram_size != 0)
256 					printk(KERN_INFO DEVICE_NAME
257 					       ": using %iK Chip RAM\n",
258 					       chip_count * Z2RAM_CHUNK1024);
259 
260 				break;
261 
262 			default:
263 				rc = -ENODEV;
264 				goto err_out;
265 
266 				break;
267 			}
268 
269 		if (z2ram_size == 0) {
270 			printk(KERN_NOTICE DEVICE_NAME
271 			       ": no unused ZII/Chip RAM found\n");
272 			goto err_out_kfree;
273 		}
274 
275 		current_device = device;
276 		z2ram_size <<= Z2RAM_CHUNKSHIFT;
277 		set_capacity(z2ram_gendisk[device], z2ram_size >> 9);
278 	}
279 
280 	mutex_unlock(&z2ram_mutex);
281 	return 0;
282 
283 err_out_kfree:
284 	kfree(z2ram_map);
285 err_out:
286 	mutex_unlock(&z2ram_mutex);
287 	return rc;
288 }
289 
z2_release(struct gendisk * disk)290 static void z2_release(struct gendisk *disk)
291 {
292 	mutex_lock(&z2ram_mutex);
293 	if (current_device == -1) {
294 		mutex_unlock(&z2ram_mutex);
295 		return;
296 	}
297 	mutex_unlock(&z2ram_mutex);
298 	/*
299 	 * FIXME: unmap memory
300 	 */
301 }
302 
303 static const struct block_device_operations z2_fops = {
304 	.owner = THIS_MODULE,
305 	.open = z2_open,
306 	.release = z2_release,
307 };
308 
309 static struct blk_mq_tag_set tag_set;
310 
311 static const struct blk_mq_ops z2_mq_ops = {
312 	.queue_rq = z2_queue_rq,
313 };
314 
z2ram_register_disk(int minor)315 static int z2ram_register_disk(int minor)
316 {
317 	struct gendisk *disk;
318 	int err;
319 
320 	disk = blk_mq_alloc_disk(&tag_set, NULL, NULL);
321 	if (IS_ERR(disk))
322 		return PTR_ERR(disk);
323 
324 	disk->major = Z2RAM_MAJOR;
325 	disk->first_minor = minor;
326 	disk->minors = 1;
327 	disk->flags |= GENHD_FL_NO_PART;
328 	disk->fops = &z2_fops;
329 	if (minor)
330 		sprintf(disk->disk_name, "z2ram%d", minor);
331 	else
332 		sprintf(disk->disk_name, "z2ram");
333 
334 	z2ram_gendisk[minor] = disk;
335 	err = add_disk(disk);
336 	if (err)
337 		put_disk(disk);
338 	return err;
339 }
340 
z2_init(void)341 static int __init z2_init(void)
342 {
343 	int ret, i;
344 
345 	if (!MACH_IS_AMIGA)
346 		return -ENODEV;
347 
348 	if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
349 		return -EBUSY;
350 
351 	tag_set.ops = &z2_mq_ops;
352 	tag_set.nr_hw_queues = 1;
353 	tag_set.nr_maps = 1;
354 	tag_set.queue_depth = 16;
355 	tag_set.numa_node = NUMA_NO_NODE;
356 	ret = blk_mq_alloc_tag_set(&tag_set);
357 	if (ret)
358 		goto out_unregister_blkdev;
359 
360 	for (i = 0; i < Z2MINOR_COUNT; i++) {
361 		ret = z2ram_register_disk(i);
362 		if (ret && i == 0)
363 			goto out_free_tagset;
364 	}
365 
366 	return 0;
367 
368 out_free_tagset:
369 	blk_mq_free_tag_set(&tag_set);
370 out_unregister_blkdev:
371 	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
372 	return ret;
373 }
374 
z2_exit(void)375 static void __exit z2_exit(void)
376 {
377 	int i, j;
378 
379 	unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
380 
381 	for (i = 0; i < Z2MINOR_COUNT; i++) {
382 		del_gendisk(z2ram_gendisk[i]);
383 		put_disk(z2ram_gendisk[i]);
384 	}
385 	blk_mq_free_tag_set(&tag_set);
386 
387 	if (current_device != -1) {
388 		i = 0;
389 
390 		for (j = 0; j < z2_count; j++) {
391 			set_bit(i++, zorro_unused_z2ram);
392 		}
393 
394 		for (j = 0; j < chip_count; j++) {
395 			if (z2ram_map[i]) {
396 				amiga_chip_free((void *)z2ram_map[i++]);
397 			}
398 		}
399 
400 		if (z2ram_map != NULL) {
401 			kfree(z2ram_map);
402 		}
403 	}
404 
405 	return;
406 }
407 
408 module_init(z2_init);
409 module_exit(z2_exit);
410 MODULE_DESCRIPTION("Amiga Zorro II ramdisk driver");
411 MODULE_LICENSE("GPL");
412