aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/s390/block/xpram.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/s390/block/xpram.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/s390/block/xpram.c')
-rw-r--r--drivers/s390/block/xpram.c539
1 files changed, 539 insertions, 0 deletions
diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
new file mode 100644
index 000000000000..d428c909b8a0
--- /dev/null
+++ b/drivers/s390/block/xpram.c
@@ -0,0 +1,539 @@
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>
39#include <linux/devfs_fs_kernel.h>
40#include <asm/uaccess.h>
41
42#define XPRAM_NAME "xpram"
43#define XPRAM_DEVS 1 /* one partition */
44#define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */
45
46#define PRINT_DEBUG(x...) printk(KERN_DEBUG XPRAM_NAME " debug:" x)
47#define PRINT_INFO(x...) printk(KERN_INFO XPRAM_NAME " info:" x)
48#define PRINT_WARN(x...) printk(KERN_WARNING XPRAM_NAME " warning:" x)
49#define PRINT_ERR(x...) printk(KERN_ERR XPRAM_NAME " error:" x)
50
51
52static struct sysdev_class xpram_sysclass = {
53 set_kset_name("xpram"),
54};
55
56static struct sys_device xpram_sys_device = {
57 .id = 0,
58 .cls = &xpram_sysclass,
59};
60
61typedef struct {
62 unsigned int size; /* size of xpram segment in pages */
63 unsigned int offset; /* start page of xpram segment */
64} xpram_device_t;
65
66static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
67static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
68static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
69static unsigned int xpram_pages;
70static int xpram_devs;
71
72/*
73 * Parameter parsing functions.
74 */
75static int devs = XPRAM_DEVS;
76static unsigned int sizes[XPRAM_MAX_DEVS];
77
78module_param(devs, int, 0);
79module_param_array(sizes, int, NULL, 0);
80
81MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
82 "the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
83MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
84 "the defaults are 0s \n" \
85 "All devices with size 0 equally partition the "
86 "remaining space on the expanded strorage not "
87 "claimed by explicit sizes\n");
88MODULE_LICENSE("GPL");
89
90#ifndef MODULE
91/*
92 * Parses the kernel parameters given in the kernel parameter line.
93 * The expected format is
94 * <number_of_partitions>[","<partition_size>]*
95 * where
96 * devices is a positive integer that initializes xpram_devs
97 * each size is a non-negative integer possibly followed by a
98 * magnitude (k,K,m,M,g,G), the list of sizes initialises
99 * xpram_sizes
100 *
101 * Arguments
102 * str: substring of kernel parameter line that contains xprams
103 * kernel parameters.
104 *
105 * Result 0 on success, -EINVAL else -- only for Version > 2.3
106 *
107 * Side effects
108 * the global variabls devs is set to the value of
109 * <number_of_partitions> and sizes[i] is set to the i-th
110 * partition size (if provided). A parsing error of a value
111 * results in this value being set to -EINVAL.
112 */
113static int __init xpram_setup (char *str)
114{
115 char *cp;
116 int i;
117
118 devs = simple_strtoul(str, &cp, 10);
119 if (cp <= str || devs > XPRAM_MAX_DEVS)
120 return 0;
121 for (i = 0; (i < devs) && (*cp++ == ','); i++) {
122 sizes[i] = simple_strtoul(cp, &cp, 10);
123 if (*cp == 'g' || *cp == 'G') {
124 sizes[i] <<= 20;
125 cp++;
126 } else if (*cp == 'm' || *cp == 'M') {
127 sizes[i] <<= 10;
128 cp++;
129 } else if (*cp == 'k' || *cp == 'K')
130 cp++;
131 while (isspace(*cp)) cp++;
132 }
133 if (*cp == ',' && i >= devs)
134 PRINT_WARN("partition sizes list has too many entries.\n");
135 else if (*cp != 0)
136 PRINT_WARN("ignored '%s' at end of parameter string.\n", cp);
137 return 1;
138}
139
140__setup("xpram_parts=", xpram_setup);
141#endif
142
143/*
144 * Copy expanded memory page (4kB) into main memory
145 * Arguments
146 * page_addr: address of target page
147 * xpage_index: index of expandeded memory page
148 * Return value
149 * 0: if operation succeeds
150 * -EIO: if pgin failed
151 * -ENXIO: if xpram has vanished
152 */
153static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
154{
155 int cc;
156
157 __asm__ __volatile__ (
158 " lhi %0,2\n" /* return unused cc 2 if pgin traps */
159 " .insn rre,0xb22e0000,%1,%2\n" /* pgin %1,%2 */
160 "0: ipm %0\n"
161 " srl %0,28\n"
162 "1:\n"
163#ifndef CONFIG_ARCH_S390X
164 ".section __ex_table,\"a\"\n"
165 " .align 4\n"
166 " .long 0b,1b\n"
167 ".previous"
168#else
169 ".section __ex_table,\"a\"\n"
170 " .align 8\n"
171 " .quad 0b,1b\n"
172 ".previous"
173#endif
174 : "=&d" (cc)
175 : "a" (__pa(page_addr)), "a" (xpage_index)
176 : "cc" );
177 if (cc == 3)
178 return -ENXIO;
179 if (cc == 2) {
180 PRINT_ERR("expanded storage lost!\n");
181 return -ENXIO;
182 }
183 if (cc == 1) {
184 PRINT_ERR("page in failed for page index %u.\n",
185 xpage_index);
186 return -EIO;
187 }
188 return 0;
189}
190
191/*
192 * Copy a 4kB page of main memory to an expanded memory page
193 * Arguments
194 * page_addr: address of source page
195 * xpage_index: index of expandeded memory page
196 * Return value
197 * 0: if operation succeeds
198 * -EIO: if pgout failed
199 * -ENXIO: if xpram has vanished
200 */
201static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
202{
203 int cc;
204
205 __asm__ __volatile__ (
206 " lhi %0,2\n" /* return unused cc 2 if pgout traps */
207 " .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */
208 "0: ipm %0\n"
209 " srl %0,28\n"
210 "1:\n"
211#ifndef CONFIG_ARCH_S390X
212 ".section __ex_table,\"a\"\n"
213 " .align 4\n"
214 " .long 0b,1b\n"
215 ".previous"
216#else
217 ".section __ex_table,\"a\"\n"
218 " .align 8\n"
219 " .quad 0b,1b\n"
220 ".previous"
221#endif
222 : "=&d" (cc)
223 : "a" (__pa(page_addr)), "a" (xpage_index)
224 : "cc" );
225 if (cc == 3)
226 return -ENXIO;
227 if (cc == 2) {
228 PRINT_ERR("expanded storage lost!\n");
229 return -ENXIO;
230 }
231 if (cc == 1) {
232 PRINT_ERR("page out failed for page index %u.\n",
233 xpage_index);
234 return -EIO;
235 }
236 return 0;
237}
238
239/*
240 * Check if xpram is available.
241 */
242static int __init xpram_present(void)
243{
244 unsigned long mem_page;
245 int rc;
246
247 mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
248 if (!mem_page)
249 return -ENOMEM;
250 rc = xpram_page_in(mem_page, 0);
251 free_page(mem_page);
252 return rc ? -ENXIO : 0;
253}
254
255/*
256 * Return index of the last available xpram page.
257 */
258static unsigned long __init xpram_highest_page_index(void)
259{
260 unsigned int page_index, add_bit;
261 unsigned long mem_page;
262
263 mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
264 if (!mem_page)
265 return 0;
266
267 page_index = 0;
268 add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
269 while (add_bit > 0) {
270 if (xpram_page_in(mem_page, page_index | add_bit) == 0)
271 page_index |= add_bit;
272 add_bit >>= 1;
273 }
274
275 free_page (mem_page);
276
277 return page_index;
278}
279
280/*
281 * Block device make request function.
282 */
283static int xpram_make_request(request_queue_t *q, struct bio *bio)
284{
285 xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
286 struct bio_vec *bvec;
287 unsigned int index;
288 unsigned long page_addr;
289 unsigned long bytes;
290 int i;
291
292 if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
293 /* Request is not page-aligned. */
294 goto fail;
295 if ((bio->bi_size >> 12) > xdev->size)
296 /* Request size is no page-aligned. */
297 goto fail;
298 if ((bio->bi_sector >> 3) > 0xffffffffU - xdev->offset)
299 goto fail;
300 index = (bio->bi_sector >> 3) + xdev->offset;
301 bio_for_each_segment(bvec, bio, i) {
302 page_addr = (unsigned long)
303 kmap(bvec->bv_page) + bvec->bv_offset;
304 bytes = bvec->bv_len;
305 if ((page_addr & 4095) != 0 || (bytes & 4095) != 0)
306 /* More paranoia. */
307 goto fail;
308 while (bytes > 0) {
309 if (bio_data_dir(bio) == READ) {
310 if (xpram_page_in(page_addr, index) != 0)
311 goto fail;
312 } else {
313 if (xpram_page_out(page_addr, index) != 0)
314 goto fail;
315 }
316 page_addr += 4096;
317 bytes -= 4096;
318 index++;
319 }
320 }
321 set_bit(BIO_UPTODATE, &bio->bi_flags);
322 bytes = bio->bi_size;
323 bio->bi_size = 0;
324 bio->bi_end_io(bio, bytes, 0);
325 return 0;
326fail:
327 bio_io_error(bio, bio->bi_size);
328 return 0;
329}
330
331static int xpram_ioctl (struct inode *inode, struct file *filp,
332 unsigned int cmd, unsigned long arg)
333{
334 struct hd_geometry __user *geo;
335 unsigned long size;
336 if (cmd != HDIO_GETGEO)
337 return -EINVAL;
338 /*
339 * get geometry: we have to fake one... trim the size to a
340 * multiple of 64 (32k): tell we have 16 sectors, 4 heads,
341 * whatever cylinders. Tell also that data starts at sector. 4.
342 */
343 geo = (struct hd_geometry __user *) arg;
344 size = (xpram_pages * 8) & ~0x3f;
345 put_user(size >> 6, &geo->cylinders);
346 put_user(4, &geo->heads);
347 put_user(16, &geo->sectors);
348 put_user(4, &geo->start);
349 return 0;
350}
351
352static struct block_device_operations xpram_devops =
353{
354 .owner = THIS_MODULE,
355 .ioctl = xpram_ioctl,
356};
357
358/*
359 * Setup xpram_sizes array.
360 */
361static int __init xpram_setup_sizes(unsigned long pages)
362{
363 unsigned long mem_needed;
364 unsigned long mem_auto;
365 int mem_auto_no;
366 int i;
367
368 /* Check number of devices. */
369 if (devs <= 0 || devs > XPRAM_MAX_DEVS) {
370 PRINT_ERR("invalid number %d of devices\n",devs);
371 return -EINVAL;
372 }
373 xpram_devs = devs;
374
375 /*
376 * Copy sizes array to xpram_sizes and align partition
377 * sizes to page boundary.
378 */
379 mem_needed = 0;
380 mem_auto_no = 0;
381 for (i = 0; i < xpram_devs; i++) {
382 xpram_sizes[i] = (sizes[i] + 3) & -4UL;
383 if (xpram_sizes[i])
384 mem_needed += xpram_sizes[i];
385 else
386 mem_auto_no++;
387 }
388
389 PRINT_INFO(" number of devices (partitions): %d \n", xpram_devs);
390 for (i = 0; i < xpram_devs; i++) {
391 if (xpram_sizes[i])
392 PRINT_INFO(" size of partition %d: %u kB\n",
393 i, xpram_sizes[i]);
394 else
395 PRINT_INFO(" size of partition %d to be set "
396 "automatically\n",i);
397 }
398 PRINT_DEBUG(" memory needed (for sized partitions): %lu kB\n",
399 mem_needed);
400 PRINT_DEBUG(" partitions to be sized automatically: %d\n",
401 mem_auto_no);
402
403 if (mem_needed > pages * 4) {
404 PRINT_ERR("Not enough expanded memory available\n");
405 return -EINVAL;
406 }
407
408 /*
409 * partitioning:
410 * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
411 * else: ; all partitions with zero xpram_sizes[i]
412 * partition equally the remaining space
413 */
414 if (mem_auto_no) {
415 mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
416 PRINT_INFO(" automatically determined "
417 "partition size: %lu kB\n", mem_auto);
418 for (i = 0; i < xpram_devs; i++)
419 if (xpram_sizes[i] == 0)
420 xpram_sizes[i] = mem_auto;
421 }
422 return 0;
423}
424
425static struct request_queue *xpram_queue;
426
427static int __init xpram_setup_blkdev(void)
428{
429 unsigned long offset;
430 int i, rc = -ENOMEM;
431
432 for (i = 0; i < xpram_devs; i++) {
433 struct gendisk *disk = alloc_disk(1);
434 if (!disk)
435 goto out;
436 xpram_disks[i] = disk;
437 }
438
439 /*
440 * Register xpram major.
441 */
442 rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
443 if (rc < 0)
444 goto out;
445
446 devfs_mk_dir("slram");
447
448 /*
449 * Assign the other needed values: make request function, sizes and
450 * hardsect size. All the minor devices feature the same value.
451 */
452 xpram_queue = blk_alloc_queue(GFP_KERNEL);
453 if (!xpram_queue) {
454 rc = -ENOMEM;
455 goto out_unreg;
456 }
457 blk_queue_make_request(xpram_queue, xpram_make_request);
458 blk_queue_hardsect_size(xpram_queue, 4096);
459
460 /*
461 * Setup device structures.
462 */
463 offset = 0;
464 for (i = 0; i < xpram_devs; i++) {
465 struct gendisk *disk = xpram_disks[i];
466
467 xpram_devices[i].size = xpram_sizes[i] / 4;
468 xpram_devices[i].offset = offset;
469 offset += xpram_devices[i].size;
470 disk->major = XPRAM_MAJOR;
471 disk->first_minor = i;
472 disk->fops = &xpram_devops;
473 disk->private_data = &xpram_devices[i];
474 disk->queue = xpram_queue;
475 sprintf(disk->disk_name, "slram%d", i);
476 sprintf(disk->devfs_name, "slram/%d", i);
477 set_capacity(disk, xpram_sizes[i] << 1);
478 add_disk(disk);
479 }
480
481 return 0;
482out_unreg:
483 devfs_remove("slram");
484 unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
485out:
486 while (i--)
487 put_disk(xpram_disks[i]);
488 return rc;
489}
490
491/*
492 * Finally, the init/exit functions.
493 */
494static void __exit xpram_exit(void)
495{
496 int i;
497 for (i = 0; i < xpram_devs; i++) {
498 del_gendisk(xpram_disks[i]);
499 put_disk(xpram_disks[i]);
500 }
501 unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
502 devfs_remove("slram");
503 blk_cleanup_queue(xpram_queue);
504 sysdev_unregister(&xpram_sys_device);
505 sysdev_class_unregister(&xpram_sysclass);
506}
507
508static int __init xpram_init(void)
509{
510 int rc;
511
512 /* Find out size of expanded memory. */
513 if (xpram_present() != 0) {
514 PRINT_WARN("No expanded memory available\n");
515 return -ENODEV;
516 }
517 xpram_pages = xpram_highest_page_index();
518 PRINT_INFO(" %u pages expanded memory found (%lu KB).\n",
519 xpram_pages, (unsigned long) xpram_pages*4);
520 rc = xpram_setup_sizes(xpram_pages);
521 if (rc)
522 return rc;
523 rc = sysdev_class_register(&xpram_sysclass);
524 if (rc)
525 return rc;
526
527 rc = sysdev_register(&xpram_sys_device);
528 if (rc) {
529 sysdev_class_unregister(&xpram_sysclass);
530 return rc;
531 }
532 rc = xpram_setup_blkdev();
533 if (rc)
534 sysdev_unregister(&xpram_sys_device);
535 return rc;
536}
537
538module_init(xpram_init);
539module_exit(xpram_exit);