Commit | Line | Data |
---|---|---|
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 | ||
d1c2f892 MS |
28 | #define KMSG_COMPONENT "xpram" |
29 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
30 | ||
1da177e4 LT |
31 | #include <linux/module.h> |
32 | #include <linux/moduleparam.h> | |
33 | #include <linux/ctype.h> /* isdigit, isxdigit */ | |
34 | #include <linux/errno.h> | |
35 | #include <linux/init.h> | |
1da177e4 LT |
36 | #include <linux/blkdev.h> |
37 | #include <linux/blkpg.h> | |
38 | #include <linux/hdreg.h> /* HDIO_GETGEO */ | |
edbaa603 | 39 | #include <linux/device.h> |
1da177e4 | 40 | #include <linux/bio.h> |
14532095 MH |
41 | #include <linux/suspend.h> |
42 | #include <linux/platform_device.h> | |
5a0e3ad6 | 43 | #include <linux/gfp.h> |
1da177e4 LT |
44 | #include <asm/uaccess.h> |
45 | ||
46 | #define XPRAM_NAME "xpram" | |
47 | #define XPRAM_DEVS 1 /* one partition */ | |
48 | #define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */ | |
49 | ||
1da177e4 LT |
50 | typedef struct { |
51 | unsigned int size; /* size of xpram segment in pages */ | |
52 | unsigned int offset; /* start page of xpram segment */ | |
53 | } xpram_device_t; | |
54 | ||
55 | static xpram_device_t xpram_devices[XPRAM_MAX_DEVS]; | |
56 | static unsigned int xpram_sizes[XPRAM_MAX_DEVS]; | |
57 | static struct gendisk *xpram_disks[XPRAM_MAX_DEVS]; | |
3ce66093 | 58 | static struct request_queue *xpram_queues[XPRAM_MAX_DEVS]; |
1da177e4 LT |
59 | static unsigned int xpram_pages; |
60 | static int xpram_devs; | |
61 | ||
62 | /* | |
63 | * Parameter parsing functions. | |
64 | */ | |
0c0db035 MS |
65 | static int devs = XPRAM_DEVS; |
66 | static char *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; | |
8df22b4b | 103 | if (cc == 2) |
1da177e4 | 104 | return -ENXIO; |
8df22b4b | 105 | if (cc == 1) |
1da177e4 | 106 | return -EIO; |
1da177e4 LT |
107 | return 0; |
108 | } | |
109 | ||
110 | /* | |
111 | * Copy a 4kB page of main memory to an expanded memory page | |
112 | * Arguments | |
113 | * page_addr: address of source page | |
114 | * xpage_index: index of expandeded memory page | |
115 | * Return value | |
116 | * 0: if operation succeeds | |
117 | * -EIO: if pgout failed | |
118 | * -ENXIO: if xpram has vanished | |
119 | */ | |
120 | static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index) | |
121 | { | |
94c12cc7 | 122 | int cc = 2; /* return unused cc 2 if pgin traps */ |
1da177e4 | 123 | |
94c12cc7 MS |
124 | asm volatile( |
125 | " .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */ | |
126 | "0: ipm %0\n" | |
127 | " srl %0,28\n" | |
1da177e4 | 128 | "1:\n" |
94c12cc7 MS |
129 | EX_TABLE(0b,1b) |
130 | : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc"); | |
1da177e4 LT |
131 | if (cc == 3) |
132 | return -ENXIO; | |
8df22b4b | 133 | if (cc == 2) |
1da177e4 | 134 | return -ENXIO; |
8df22b4b | 135 | if (cc == 1) |
1da177e4 | 136 | return -EIO; |
1da177e4 LT |
137 | return 0; |
138 | } | |
139 | ||
140 | /* | |
141 | * Check if xpram is available. | |
142 | */ | |
14532095 | 143 | static int xpram_present(void) |
1da177e4 LT |
144 | { |
145 | unsigned long mem_page; | |
146 | int rc; | |
147 | ||
148 | mem_page = (unsigned long) __get_free_page(GFP_KERNEL); | |
149 | if (!mem_page) | |
150 | return -ENOMEM; | |
151 | rc = xpram_page_in(mem_page, 0); | |
152 | free_page(mem_page); | |
153 | return rc ? -ENXIO : 0; | |
154 | } | |
155 | ||
156 | /* | |
157 | * Return index of the last available xpram page. | |
158 | */ | |
14532095 | 159 | static unsigned long xpram_highest_page_index(void) |
1da177e4 LT |
160 | { |
161 | unsigned int page_index, add_bit; | |
162 | unsigned long mem_page; | |
163 | ||
164 | mem_page = (unsigned long) __get_free_page(GFP_KERNEL); | |
165 | if (!mem_page) | |
166 | return 0; | |
167 | ||
168 | page_index = 0; | |
169 | add_bit = 1ULL << (sizeof(unsigned int)*8 - 1); | |
170 | while (add_bit > 0) { | |
171 | if (xpram_page_in(mem_page, page_index | add_bit) == 0) | |
172 | page_index |= add_bit; | |
173 | add_bit >>= 1; | |
174 | } | |
175 | ||
176 | free_page (mem_page); | |
177 | ||
178 | return page_index; | |
179 | } | |
180 | ||
181 | /* | |
182 | * Block device make request function. | |
183 | */ | |
5a7bbad2 | 184 | static void xpram_make_request(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
185 | { |
186 | xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data; | |
187 | struct bio_vec *bvec; | |
188 | unsigned int index; | |
189 | unsigned long page_addr; | |
190 | unsigned long bytes; | |
191 | int i; | |
192 | ||
4f024f37 KO |
193 | if ((bio->bi_iter.bi_sector & 7) != 0 || |
194 | (bio->bi_iter.bi_size & 4095) != 0) | |
1da177e4 LT |
195 | /* Request is not page-aligned. */ |
196 | goto fail; | |
4f024f37 | 197 | if ((bio->bi_iter.bi_size >> 12) > xdev->size) |
1da177e4 LT |
198 | /* Request size is no page-aligned. */ |
199 | goto fail; | |
4f024f37 | 200 | if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset) |
1da177e4 | 201 | goto fail; |
4f024f37 | 202 | index = (bio->bi_iter.bi_sector >> 3) + xdev->offset; |
1da177e4 LT |
203 | bio_for_each_segment(bvec, bio, i) { |
204 | page_addr = (unsigned long) | |
205 | kmap(bvec->bv_page) + bvec->bv_offset; | |
206 | bytes = bvec->bv_len; | |
207 | if ((page_addr & 4095) != 0 || (bytes & 4095) != 0) | |
208 | /* More paranoia. */ | |
209 | goto fail; | |
210 | while (bytes > 0) { | |
211 | if (bio_data_dir(bio) == READ) { | |
212 | if (xpram_page_in(page_addr, index) != 0) | |
213 | goto fail; | |
214 | } else { | |
215 | if (xpram_page_out(page_addr, index) != 0) | |
216 | goto fail; | |
217 | } | |
218 | page_addr += 4096; | |
219 | bytes -= 4096; | |
220 | index++; | |
221 | } | |
222 | } | |
223 | set_bit(BIO_UPTODATE, &bio->bi_flags); | |
1462222b | 224 | bio_endio(bio, 0); |
5a7bbad2 | 225 | return; |
1da177e4 | 226 | fail: |
6712ecf8 | 227 | bio_io_error(bio); |
1da177e4 LT |
228 | } |
229 | ||
a885c8c4 | 230 | static int xpram_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1da177e4 | 231 | { |
1da177e4 | 232 | unsigned long size; |
a885c8c4 | 233 | |
1da177e4 LT |
234 | /* |
235 | * get geometry: we have to fake one... trim the size to a | |
236 | * multiple of 64 (32k): tell we have 16 sectors, 4 heads, | |
237 | * whatever cylinders. Tell also that data starts at sector. 4. | |
238 | */ | |
1da177e4 | 239 | size = (xpram_pages * 8) & ~0x3f; |
a885c8c4 CH |
240 | geo->cylinders = size >> 6; |
241 | geo->heads = 4; | |
242 | geo->sectors = 16; | |
243 | geo->start = 4; | |
1da177e4 LT |
244 | return 0; |
245 | } | |
246 | ||
83d5cde4 | 247 | static const struct block_device_operations xpram_devops = |
1da177e4 LT |
248 | { |
249 | .owner = THIS_MODULE, | |
a885c8c4 | 250 | .getgeo = xpram_getgeo, |
1da177e4 LT |
251 | }; |
252 | ||
253 | /* | |
254 | * Setup xpram_sizes array. | |
255 | */ | |
256 | static int __init xpram_setup_sizes(unsigned long pages) | |
257 | { | |
258 | unsigned long mem_needed; | |
259 | unsigned long mem_auto; | |
f257b063 | 260 | unsigned long long size; |
1da177e4 LT |
261 | int mem_auto_no; |
262 | int i; | |
263 | ||
264 | /* Check number of devices. */ | |
265 | if (devs <= 0 || devs > XPRAM_MAX_DEVS) { | |
d1c2f892 | 266 | pr_err("%d is not a valid number of XPRAM devices\n",devs); |
1da177e4 LT |
267 | return -EINVAL; |
268 | } | |
269 | xpram_devs = devs; | |
270 | ||
271 | /* | |
272 | * Copy sizes array to xpram_sizes and align partition | |
273 | * sizes to page boundary. | |
274 | */ | |
275 | mem_needed = 0; | |
276 | mem_auto_no = 0; | |
277 | for (i = 0; i < xpram_devs; i++) { | |
f257b063 HC |
278 | if (sizes[i]) { |
279 | size = simple_strtoull(sizes[i], &sizes[i], 0); | |
280 | switch (sizes[i][0]) { | |
281 | case 'g': | |
282 | case 'G': | |
283 | size <<= 20; | |
284 | break; | |
285 | case 'm': | |
286 | case 'M': | |
287 | size <<= 10; | |
288 | } | |
289 | xpram_sizes[i] = (size + 3) & -4UL; | |
290 | } | |
1da177e4 LT |
291 | if (xpram_sizes[i]) |
292 | mem_needed += xpram_sizes[i]; | |
293 | else | |
294 | mem_auto_no++; | |
295 | } | |
296 | ||
d1c2f892 | 297 | pr_info(" number of devices (partitions): %d \n", xpram_devs); |
1da177e4 LT |
298 | for (i = 0; i < xpram_devs; i++) { |
299 | if (xpram_sizes[i]) | |
d1c2f892 MS |
300 | pr_info(" size of partition %d: %u kB\n", |
301 | i, xpram_sizes[i]); | |
1da177e4 | 302 | else |
d1c2f892 MS |
303 | pr_info(" size of partition %d to be set " |
304 | "automatically\n",i); | |
1da177e4 | 305 | } |
d1c2f892 MS |
306 | pr_info(" memory needed (for sized partitions): %lu kB\n", |
307 | mem_needed); | |
308 | pr_info(" partitions to be sized automatically: %d\n", | |
309 | mem_auto_no); | |
1da177e4 LT |
310 | |
311 | if (mem_needed > pages * 4) { | |
d1c2f892 | 312 | pr_err("Not enough expanded memory available\n"); |
1da177e4 LT |
313 | return -EINVAL; |
314 | } | |
315 | ||
316 | /* | |
317 | * partitioning: | |
318 | * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB | |
319 | * else: ; all partitions with zero xpram_sizes[i] | |
320 | * partition equally the remaining space | |
321 | */ | |
322 | if (mem_auto_no) { | |
323 | mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4; | |
d1c2f892 MS |
324 | pr_info(" automatically determined " |
325 | "partition size: %lu kB\n", mem_auto); | |
1da177e4 LT |
326 | for (i = 0; i < xpram_devs; i++) |
327 | if (xpram_sizes[i] == 0) | |
328 | xpram_sizes[i] = mem_auto; | |
329 | } | |
330 | return 0; | |
331 | } | |
332 | ||
1da177e4 LT |
333 | static int __init xpram_setup_blkdev(void) |
334 | { | |
335 | unsigned long offset; | |
336 | int i, rc = -ENOMEM; | |
337 | ||
338 | for (i = 0; i < xpram_devs; i++) { | |
3ce66093 MS |
339 | xpram_disks[i] = alloc_disk(1); |
340 | if (!xpram_disks[i]) | |
341 | goto out; | |
342 | xpram_queues[i] = blk_alloc_queue(GFP_KERNEL); | |
343 | if (!xpram_queues[i]) { | |
344 | put_disk(xpram_disks[i]); | |
1da177e4 | 345 | goto out; |
3ce66093 | 346 | } |
00e5d35c | 347 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, xpram_queues[i]); |
3ce66093 | 348 | blk_queue_make_request(xpram_queues[i], xpram_make_request); |
e1defc4f | 349 | blk_queue_logical_block_size(xpram_queues[i], 4096); |
1da177e4 LT |
350 | } |
351 | ||
352 | /* | |
353 | * Register xpram major. | |
354 | */ | |
355 | rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME); | |
356 | if (rc < 0) | |
357 | goto out; | |
358 | ||
1da177e4 LT |
359 | /* |
360 | * Setup device structures. | |
361 | */ | |
362 | offset = 0; | |
363 | for (i = 0; i < xpram_devs; i++) { | |
364 | struct gendisk *disk = xpram_disks[i]; | |
365 | ||
366 | xpram_devices[i].size = xpram_sizes[i] / 4; | |
367 | xpram_devices[i].offset = offset; | |
368 | offset += xpram_devices[i].size; | |
369 | disk->major = XPRAM_MAJOR; | |
370 | disk->first_minor = i; | |
371 | disk->fops = &xpram_devops; | |
372 | disk->private_data = &xpram_devices[i]; | |
3ce66093 | 373 | disk->queue = xpram_queues[i]; |
1da177e4 | 374 | sprintf(disk->disk_name, "slram%d", i); |
1da177e4 LT |
375 | set_capacity(disk, xpram_sizes[i] << 1); |
376 | add_disk(disk); | |
377 | } | |
378 | ||
379 | return 0; | |
1da177e4 | 380 | out: |
3ce66093 MS |
381 | while (i--) { |
382 | blk_cleanup_queue(xpram_queues[i]); | |
1da177e4 | 383 | put_disk(xpram_disks[i]); |
3ce66093 | 384 | } |
1da177e4 LT |
385 | return rc; |
386 | } | |
387 | ||
14532095 MH |
388 | /* |
389 | * Resume failed: Print error message and call panic. | |
390 | */ | |
391 | static void xpram_resume_error(const char *message) | |
392 | { | |
2c48c4d6 | 393 | pr_err("Resuming the system failed: %s\n", message); |
14532095 MH |
394 | panic("xpram resume error\n"); |
395 | } | |
396 | ||
397 | /* | |
398 | * Check if xpram setup changed between suspend and resume. | |
399 | */ | |
400 | static int xpram_restore(struct device *dev) | |
401 | { | |
402 | if (!xpram_pages) | |
403 | return 0; | |
404 | if (xpram_present() != 0) | |
405 | xpram_resume_error("xpram disappeared"); | |
406 | if (xpram_pages != xpram_highest_page_index() + 1) | |
407 | xpram_resume_error("Size of xpram changed"); | |
14532095 MH |
408 | return 0; |
409 | } | |
410 | ||
47145210 | 411 | static const struct dev_pm_ops xpram_pm_ops = { |
14532095 MH |
412 | .restore = xpram_restore, |
413 | }; | |
414 | ||
415 | static struct platform_driver xpram_pdrv = { | |
416 | .driver = { | |
417 | .name = XPRAM_NAME, | |
418 | .owner = THIS_MODULE, | |
419 | .pm = &xpram_pm_ops, | |
420 | }, | |
421 | }; | |
422 | ||
423 | static struct platform_device *xpram_pdev; | |
424 | ||
1da177e4 LT |
425 | /* |
426 | * Finally, the init/exit functions. | |
427 | */ | |
428 | static void __exit xpram_exit(void) | |
429 | { | |
430 | int i; | |
431 | for (i = 0; i < xpram_devs; i++) { | |
432 | del_gendisk(xpram_disks[i]); | |
3ce66093 | 433 | blk_cleanup_queue(xpram_queues[i]); |
1da177e4 LT |
434 | put_disk(xpram_disks[i]); |
435 | } | |
436 | unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME); | |
14532095 MH |
437 | platform_device_unregister(xpram_pdev); |
438 | platform_driver_unregister(&xpram_pdrv); | |
1da177e4 LT |
439 | } |
440 | ||
441 | static int __init xpram_init(void) | |
442 | { | |
443 | int rc; | |
444 | ||
445 | /* Find out size of expanded memory. */ | |
446 | if (xpram_present() != 0) { | |
d1c2f892 | 447 | pr_err("No expanded memory available\n"); |
1da177e4 LT |
448 | return -ENODEV; |
449 | } | |
e620c494 | 450 | xpram_pages = xpram_highest_page_index() + 1; |
d1c2f892 MS |
451 | pr_info(" %u pages expanded memory found (%lu KB).\n", |
452 | xpram_pages, (unsigned long) xpram_pages*4); | |
1da177e4 LT |
453 | rc = xpram_setup_sizes(xpram_pages); |
454 | if (rc) | |
455 | return rc; | |
14532095 MH |
456 | rc = platform_driver_register(&xpram_pdrv); |
457 | if (rc) | |
458 | return rc; | |
459 | xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0); | |
460 | if (IS_ERR(xpram_pdev)) { | |
461 | rc = PTR_ERR(xpram_pdev); | |
462 | goto fail_platform_driver_unregister; | |
463 | } | |
464 | rc = xpram_setup_blkdev(); | |
465 | if (rc) | |
466 | goto fail_platform_device_unregister; | |
467 | return 0; | |
468 | ||
469 | fail_platform_device_unregister: | |
470 | platform_device_unregister(xpram_pdev); | |
471 | fail_platform_driver_unregister: | |
472 | platform_driver_unregister(&xpram_pdrv); | |
473 | return rc; | |
1da177e4 LT |
474 | } |
475 | ||
476 | module_init(xpram_init); | |
477 | module_exit(xpram_exit); |