Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Xpram.c -- the S/390 expanded memory RAM-disk | |
3 | * | |
4 | * significant parts of this code are based on | |
5 | * the sbull device driver presented in | |
6 | * A. Rubini: Linux Device Drivers | |
7 | * | |
8 | * Author of XPRAM specific coding: Reinhard Buendgen | |
9 | * buendgen@de.ibm.com | |
10 | * Rewrite for 2.5: Martin Schwidefsky <schwidefsky@de.ibm.com> | |
11 | * | |
12 | * External interfaces: | |
13 | * Interfaces to linux kernel | |
14 | * xpram_setup: read kernel parameters | |
15 | * Device specific file operations | |
16 | * xpram_iotcl | |
17 | * xpram_open | |
18 | * | |
19 | * "ad-hoc" partitioning: | |
20 | * the expanded memory can be partitioned among several devices | |
21 | * (with different minors). The partitioning set up can be | |
22 | * set by kernel or module parameters (int devs & int sizes[]) | |
23 | * | |
24 | * Potential future improvements: | |
25 | * generic hard disk support to replace ad-hoc partitioning | |
26 | */ | |
27 | ||
28 | #include <linux/module.h> | |
29 | #include <linux/moduleparam.h> | |
30 | #include <linux/ctype.h> /* isdigit, isxdigit */ | |
31 | #include <linux/errno.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/slab.h> | |
34 | #include <linux/blkdev.h> | |
35 | #include <linux/blkpg.h> | |
36 | #include <linux/hdreg.h> /* HDIO_GETGEO */ | |
37 | #include <linux/sysdev.h> | |
38 | #include <linux/bio.h> | |
1da177e4 LT |
39 | #include <asm/uaccess.h> |
40 | ||
41 | #define XPRAM_NAME "xpram" | |
42 | #define XPRAM_DEVS 1 /* one partition */ | |
43 | #define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */ | |
44 | ||
45 | #define PRINT_DEBUG(x...) printk(KERN_DEBUG XPRAM_NAME " debug:" x) | |
46 | #define PRINT_INFO(x...) printk(KERN_INFO XPRAM_NAME " info:" x) | |
47 | #define PRINT_WARN(x...) printk(KERN_WARNING XPRAM_NAME " warning:" x) | |
48 | #define PRINT_ERR(x...) printk(KERN_ERR XPRAM_NAME " error:" x) | |
49 | ||
50 | ||
1da177e4 LT |
51 | typedef struct { |
52 | unsigned int size; /* size of xpram segment in pages */ | |
53 | unsigned int offset; /* start page of xpram segment */ | |
54 | } xpram_device_t; | |
55 | ||
56 | static xpram_device_t xpram_devices[XPRAM_MAX_DEVS]; | |
57 | static unsigned int xpram_sizes[XPRAM_MAX_DEVS]; | |
58 | static struct gendisk *xpram_disks[XPRAM_MAX_DEVS]; | |
59 | static unsigned int xpram_pages; | |
60 | static int xpram_devs; | |
61 | ||
62 | /* | |
63 | * Parameter parsing functions. | |
64 | */ | |
5c898ba9 HC |
65 | static int __initdata devs = XPRAM_DEVS; |
66 | static char __initdata *sizes[XPRAM_MAX_DEVS]; | |
1da177e4 LT |
67 | |
68 | module_param(devs, int, 0); | |
5c898ba9 | 69 | module_param_array(sizes, charp, NULL, 0); |
1da177e4 LT |
70 | |
71 | MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \ | |
72 | "the default is " __MODULE_STRING(XPRAM_DEVS) "\n"); | |
73 | MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \ | |
74 | "the defaults are 0s \n" \ | |
75 | "All devices with size 0 equally partition the " | |
76 | "remaining space on the expanded strorage not " | |
77 | "claimed by explicit sizes\n"); | |
78 | MODULE_LICENSE("GPL"); | |
79 | ||
1da177e4 LT |
80 | /* |
81 | * Copy expanded memory page (4kB) into main memory | |
82 | * Arguments | |
83 | * page_addr: address of target page | |
84 | * xpage_index: index of expandeded memory page | |
85 | * Return value | |
86 | * 0: if operation succeeds | |
87 | * -EIO: if pgin failed | |
88 | * -ENXIO: if xpram has vanished | |
89 | */ | |
90 | static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index) | |
91 | { | |
94c12cc7 | 92 | int cc = 2; /* return unused cc 2 if pgin traps */ |
1da177e4 | 93 | |
94c12cc7 MS |
94 | asm volatile( |
95 | " .insn rre,0xb22e0000,%1,%2\n" /* pgin %1,%2 */ | |
96 | "0: ipm %0\n" | |
97 | " srl %0,28\n" | |
1da177e4 | 98 | "1:\n" |
94c12cc7 MS |
99 | EX_TABLE(0b,1b) |
100 | : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc"); | |
1da177e4 LT |
101 | if (cc == 3) |
102 | return -ENXIO; | |
103 | if (cc == 2) { | |
104 | PRINT_ERR("expanded storage lost!\n"); | |
105 | return -ENXIO; | |
106 | } | |
107 | if (cc == 1) { | |
108 | PRINT_ERR("page in failed for page index %u.\n", | |
109 | xpage_index); | |
110 | return -EIO; | |
111 | } | |
112 | return 0; | |
113 | } | |
114 | ||
115 | /* | |
116 | * Copy a 4kB page of main memory to an expanded memory page | |
117 | * Arguments | |
118 | * page_addr: address of source page | |
119 | * xpage_index: index of expandeded memory page | |
120 | * Return value | |
121 | * 0: if operation succeeds | |
122 | * -EIO: if pgout failed | |
123 | * -ENXIO: if xpram has vanished | |
124 | */ | |
125 | static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index) | |
126 | { | |
94c12cc7 | 127 | int cc = 2; /* return unused cc 2 if pgin traps */ |
1da177e4 | 128 | |
94c12cc7 MS |
129 | asm volatile( |
130 | " .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */ | |
131 | "0: ipm %0\n" | |
132 | " srl %0,28\n" | |
1da177e4 | 133 | "1:\n" |
94c12cc7 MS |
134 | EX_TABLE(0b,1b) |
135 | : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc"); | |
1da177e4 LT |
136 | if (cc == 3) |
137 | return -ENXIO; | |
138 | if (cc == 2) { | |
139 | PRINT_ERR("expanded storage lost!\n"); | |
140 | return -ENXIO; | |
141 | } | |
142 | if (cc == 1) { | |
143 | PRINT_ERR("page out failed for page index %u.\n", | |
144 | xpage_index); | |
145 | return -EIO; | |
146 | } | |
147 | return 0; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Check if xpram is available. | |
152 | */ | |
153 | static int __init xpram_present(void) | |
154 | { | |
155 | unsigned long mem_page; | |
156 | int rc; | |
157 | ||
158 | mem_page = (unsigned long) __get_free_page(GFP_KERNEL); | |
159 | if (!mem_page) | |
160 | return -ENOMEM; | |
161 | rc = xpram_page_in(mem_page, 0); | |
162 | free_page(mem_page); | |
163 | return rc ? -ENXIO : 0; | |
164 | } | |
165 | ||
166 | /* | |
167 | * Return index of the last available xpram page. | |
168 | */ | |
169 | static unsigned long __init xpram_highest_page_index(void) | |
170 | { | |
171 | unsigned int page_index, add_bit; | |
172 | unsigned long mem_page; | |
173 | ||
174 | mem_page = (unsigned long) __get_free_page(GFP_KERNEL); | |
175 | if (!mem_page) | |
176 | return 0; | |
177 | ||
178 | page_index = 0; | |
179 | add_bit = 1ULL << (sizeof(unsigned int)*8 - 1); | |
180 | while (add_bit > 0) { | |
181 | if (xpram_page_in(mem_page, page_index | add_bit) == 0) | |
182 | page_index |= add_bit; | |
183 | add_bit >>= 1; | |
184 | } | |
185 | ||
186 | free_page (mem_page); | |
187 | ||
188 | return page_index; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Block device make request function. | |
193 | */ | |
165125e1 | 194 | static int xpram_make_request(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
195 | { |
196 | xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data; | |
197 | struct bio_vec *bvec; | |
198 | unsigned int index; | |
199 | unsigned long page_addr; | |
200 | unsigned long bytes; | |
201 | int i; | |
202 | ||
203 | if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) | |
204 | /* Request is not page-aligned. */ | |
205 | goto fail; | |
206 | if ((bio->bi_size >> 12) > xdev->size) | |
207 | /* Request size is no page-aligned. */ | |
208 | goto fail; | |
209 | if ((bio->bi_sector >> 3) > 0xffffffffU - xdev->offset) | |
210 | goto fail; | |
211 | index = (bio->bi_sector >> 3) + xdev->offset; | |
212 | bio_for_each_segment(bvec, bio, i) { | |
213 | page_addr = (unsigned long) | |
214 | kmap(bvec->bv_page) + bvec->bv_offset; | |
215 | bytes = bvec->bv_len; | |
216 | if ((page_addr & 4095) != 0 || (bytes & 4095) != 0) | |
217 | /* More paranoia. */ | |
218 | goto fail; | |
219 | while (bytes > 0) { | |
220 | if (bio_data_dir(bio) == READ) { | |
221 | if (xpram_page_in(page_addr, index) != 0) | |
222 | goto fail; | |
223 | } else { | |
224 | if (xpram_page_out(page_addr, index) != 0) | |
225 | goto fail; | |
226 | } | |
227 | page_addr += 4096; | |
228 | bytes -= 4096; | |
229 | index++; | |
230 | } | |
231 | } | |
232 | set_bit(BIO_UPTODATE, &bio->bi_flags); | |
6712ecf8 | 233 | bio_end_io(bio, 0); |
1da177e4 LT |
234 | return 0; |
235 | fail: | |
6712ecf8 | 236 | bio_io_error(bio); |
1da177e4 LT |
237 | return 0; |
238 | } | |
239 | ||
a885c8c4 | 240 | static int xpram_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1da177e4 | 241 | { |
1da177e4 | 242 | unsigned long size; |
a885c8c4 | 243 | |
1da177e4 LT |
244 | /* |
245 | * get geometry: we have to fake one... trim the size to a | |
246 | * multiple of 64 (32k): tell we have 16 sectors, 4 heads, | |
247 | * whatever cylinders. Tell also that data starts at sector. 4. | |
248 | */ | |
1da177e4 | 249 | size = (xpram_pages * 8) & ~0x3f; |
a885c8c4 CH |
250 | geo->cylinders = size >> 6; |
251 | geo->heads = 4; | |
252 | geo->sectors = 16; | |
253 | geo->start = 4; | |
1da177e4 LT |
254 | return 0; |
255 | } | |
256 | ||
257 | static struct block_device_operations xpram_devops = | |
258 | { | |
259 | .owner = THIS_MODULE, | |
a885c8c4 | 260 | .getgeo = xpram_getgeo, |
1da177e4 LT |
261 | }; |
262 | ||
263 | /* | |
264 | * Setup xpram_sizes array. | |
265 | */ | |
266 | static int __init xpram_setup_sizes(unsigned long pages) | |
267 | { | |
268 | unsigned long mem_needed; | |
269 | unsigned long mem_auto; | |
f257b063 | 270 | unsigned long long size; |
1da177e4 LT |
271 | int mem_auto_no; |
272 | int i; | |
273 | ||
274 | /* Check number of devices. */ | |
275 | if (devs <= 0 || devs > XPRAM_MAX_DEVS) { | |
276 | PRINT_ERR("invalid number %d of devices\n",devs); | |
277 | return -EINVAL; | |
278 | } | |
279 | xpram_devs = devs; | |
280 | ||
281 | /* | |
282 | * Copy sizes array to xpram_sizes and align partition | |
283 | * sizes to page boundary. | |
284 | */ | |
285 | mem_needed = 0; | |
286 | mem_auto_no = 0; | |
287 | for (i = 0; i < xpram_devs; i++) { | |
f257b063 HC |
288 | if (sizes[i]) { |
289 | size = simple_strtoull(sizes[i], &sizes[i], 0); | |
290 | switch (sizes[i][0]) { | |
291 | case 'g': | |
292 | case 'G': | |
293 | size <<= 20; | |
294 | break; | |
295 | case 'm': | |
296 | case 'M': | |
297 | size <<= 10; | |
298 | } | |
299 | xpram_sizes[i] = (size + 3) & -4UL; | |
300 | } | |
1da177e4 LT |
301 | if (xpram_sizes[i]) |
302 | mem_needed += xpram_sizes[i]; | |
303 | else | |
304 | mem_auto_no++; | |
305 | } | |
306 | ||
307 | PRINT_INFO(" number of devices (partitions): %d \n", xpram_devs); | |
308 | for (i = 0; i < xpram_devs; i++) { | |
309 | if (xpram_sizes[i]) | |
310 | PRINT_INFO(" size of partition %d: %u kB\n", | |
311 | i, xpram_sizes[i]); | |
312 | else | |
313 | PRINT_INFO(" size of partition %d to be set " | |
314 | "automatically\n",i); | |
315 | } | |
316 | PRINT_DEBUG(" memory needed (for sized partitions): %lu kB\n", | |
317 | mem_needed); | |
318 | PRINT_DEBUG(" partitions to be sized automatically: %d\n", | |
319 | mem_auto_no); | |
320 | ||
321 | if (mem_needed > pages * 4) { | |
322 | PRINT_ERR("Not enough expanded memory available\n"); | |
323 | return -EINVAL; | |
324 | } | |
325 | ||
326 | /* | |
327 | * partitioning: | |
328 | * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB | |
329 | * else: ; all partitions with zero xpram_sizes[i] | |
330 | * partition equally the remaining space | |
331 | */ | |
332 | if (mem_auto_no) { | |
333 | mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4; | |
334 | PRINT_INFO(" automatically determined " | |
335 | "partition size: %lu kB\n", mem_auto); | |
336 | for (i = 0; i < xpram_devs; i++) | |
337 | if (xpram_sizes[i] == 0) | |
338 | xpram_sizes[i] = mem_auto; | |
339 | } | |
340 | return 0; | |
341 | } | |
342 | ||
343 | static struct request_queue *xpram_queue; | |
344 | ||
345 | static int __init xpram_setup_blkdev(void) | |
346 | { | |
347 | unsigned long offset; | |
348 | int i, rc = -ENOMEM; | |
349 | ||
350 | for (i = 0; i < xpram_devs; i++) { | |
351 | struct gendisk *disk = alloc_disk(1); | |
352 | if (!disk) | |
353 | goto out; | |
354 | xpram_disks[i] = disk; | |
355 | } | |
356 | ||
357 | /* | |
358 | * Register xpram major. | |
359 | */ | |
360 | rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME); | |
361 | if (rc < 0) | |
362 | goto out; | |
363 | ||
1da177e4 LT |
364 | /* |
365 | * Assign the other needed values: make request function, sizes and | |
366 | * hardsect size. All the minor devices feature the same value. | |
367 | */ | |
368 | xpram_queue = blk_alloc_queue(GFP_KERNEL); | |
369 | if (!xpram_queue) { | |
370 | rc = -ENOMEM; | |
371 | goto out_unreg; | |
372 | } | |
373 | blk_queue_make_request(xpram_queue, xpram_make_request); | |
374 | blk_queue_hardsect_size(xpram_queue, 4096); | |
375 | ||
376 | /* | |
377 | * Setup device structures. | |
378 | */ | |
379 | offset = 0; | |
380 | for (i = 0; i < xpram_devs; i++) { | |
381 | struct gendisk *disk = xpram_disks[i]; | |
382 | ||
383 | xpram_devices[i].size = xpram_sizes[i] / 4; | |
384 | xpram_devices[i].offset = offset; | |
385 | offset += xpram_devices[i].size; | |
386 | disk->major = XPRAM_MAJOR; | |
387 | disk->first_minor = i; | |
388 | disk->fops = &xpram_devops; | |
389 | disk->private_data = &xpram_devices[i]; | |
390 | disk->queue = xpram_queue; | |
391 | sprintf(disk->disk_name, "slram%d", i); | |
1da177e4 LT |
392 | set_capacity(disk, xpram_sizes[i] << 1); |
393 | add_disk(disk); | |
394 | } | |
395 | ||
396 | return 0; | |
397 | out_unreg: | |
1da177e4 LT |
398 | unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME); |
399 | out: | |
400 | while (i--) | |
401 | put_disk(xpram_disks[i]); | |
402 | return rc; | |
403 | } | |
404 | ||
405 | /* | |
406 | * Finally, the init/exit functions. | |
407 | */ | |
408 | static void __exit xpram_exit(void) | |
409 | { | |
410 | int i; | |
411 | for (i = 0; i < xpram_devs; i++) { | |
412 | del_gendisk(xpram_disks[i]); | |
413 | put_disk(xpram_disks[i]); | |
414 | } | |
415 | unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME); | |
1da177e4 | 416 | blk_cleanup_queue(xpram_queue); |
1da177e4 LT |
417 | } |
418 | ||
419 | static int __init xpram_init(void) | |
420 | { | |
421 | int rc; | |
422 | ||
423 | /* Find out size of expanded memory. */ | |
424 | if (xpram_present() != 0) { | |
425 | PRINT_WARN("No expanded memory available\n"); | |
426 | return -ENODEV; | |
427 | } | |
e620c494 | 428 | xpram_pages = xpram_highest_page_index() + 1; |
1da177e4 LT |
429 | PRINT_INFO(" %u pages expanded memory found (%lu KB).\n", |
430 | xpram_pages, (unsigned long) xpram_pages*4); | |
431 | rc = xpram_setup_sizes(xpram_pages); | |
432 | if (rc) | |
433 | return rc; | |
37ab46a3 | 434 | return xpram_setup_blkdev(); |
1da177e4 LT |
435 | } |
436 | ||
437 | module_init(xpram_init); | |
438 | module_exit(xpram_exit); |