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28#define KMSG_COMPONENT "xpram"
29#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
30
31#include <linux/module.h>
32#include <linux/moduleparam.h>
33#include <linux/ctype.h>
34#include <linux/errno.h>
35#include <linux/init.h>
36#include <linux/blkdev.h>
37#include <linux/blkpg.h>
38#include <linux/hdreg.h>
39#include <linux/device.h>
40#include <linux/bio.h>
41#include <linux/suspend.h>
42#include <linux/platform_device.h>
43#include <linux/gfp.h>
44#include <asm/uaccess.h>
45
46#define XPRAM_NAME "xpram"
47#define XPRAM_DEVS 1
48#define XPRAM_MAX_DEVS 32
49
50typedef struct {
51 unsigned int size;
52 unsigned int offset;
53} xpram_device_t;
54
55static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
56static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
57static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
58static struct request_queue *xpram_queues[XPRAM_MAX_DEVS];
59static unsigned int xpram_pages;
60static int xpram_devs;
61
62
63
64
65static int devs = XPRAM_DEVS;
66static char *sizes[XPRAM_MAX_DEVS];
67
68module_param(devs, int, 0);
69module_param_array(sizes, charp, NULL, 0);
70
71MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
72 "the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
73MODULE_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");
78MODULE_LICENSE("GPL");
79
80
81
82
83
84
85
86
87
88
89
90static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
91{
92 int cc = 2;
93
94 asm volatile(
95 " .insn rre,0xb22e0000,%1,%2\n"
96 "0: ipm %0\n"
97 " srl %0,28\n"
98 "1:\n"
99 EX_TABLE(0b,1b)
100 : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
101 if (cc == 3)
102 return -ENXIO;
103 if (cc == 2)
104 return -ENXIO;
105 if (cc == 1)
106 return -EIO;
107 return 0;
108}
109
110
111
112
113
114
115
116
117
118
119
120static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
121{
122 int cc = 2;
123
124 asm volatile(
125 " .insn rre,0xb22f0000,%1,%2\n"
126 "0: ipm %0\n"
127 " srl %0,28\n"
128 "1:\n"
129 EX_TABLE(0b,1b)
130 : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
131 if (cc == 3)
132 return -ENXIO;
133 if (cc == 2)
134 return -ENXIO;
135 if (cc == 1)
136 return -EIO;
137 return 0;
138}
139
140
141
142
143static int xpram_present(void)
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
158
159static unsigned long xpram_highest_page_index(void)
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
183
184static void xpram_make_request(struct request_queue *q, struct bio *bio)
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
193 if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
194
195 goto fail;
196 if ((bio->bi_size >> 12) > xdev->size)
197
198 goto fail;
199 if ((bio->bi_sector >> 3) > 0xffffffffU - xdev->offset)
200 goto fail;
201 index = (bio->bi_sector >> 3) + xdev->offset;
202 bio_for_each_segment(bvec, bio, i) {
203 page_addr = (unsigned long)
204 kmap(bvec->bv_page) + bvec->bv_offset;
205 bytes = bvec->bv_len;
206 if ((page_addr & 4095) != 0 || (bytes & 4095) != 0)
207
208 goto fail;
209 while (bytes > 0) {
210 if (bio_data_dir(bio) == READ) {
211 if (xpram_page_in(page_addr, index) != 0)
212 goto fail;
213 } else {
214 if (xpram_page_out(page_addr, index) != 0)
215 goto fail;
216 }
217 page_addr += 4096;
218 bytes -= 4096;
219 index++;
220 }
221 }
222 set_bit(BIO_UPTODATE, &bio->bi_flags);
223 bio_endio(bio, 0);
224 return;
225fail:
226 bio_io_error(bio);
227}
228
229static int xpram_getgeo(struct block_device *bdev, struct hd_geometry *geo)
230{
231 unsigned long size;
232
233
234
235
236
237
238 size = (xpram_pages * 8) & ~0x3f;
239 geo->cylinders = size >> 6;
240 geo->heads = 4;
241 geo->sectors = 16;
242 geo->start = 4;
243 return 0;
244}
245
246static const struct block_device_operations xpram_devops =
247{
248 .owner = THIS_MODULE,
249 .getgeo = xpram_getgeo,
250};
251
252
253
254
255static int __init xpram_setup_sizes(unsigned long pages)
256{
257 unsigned long mem_needed;
258 unsigned long mem_auto;
259 unsigned long long size;
260 int mem_auto_no;
261 int i;
262
263
264 if (devs <= 0 || devs > XPRAM_MAX_DEVS) {
265 pr_err("%d is not a valid number of XPRAM devices\n",devs);
266 return -EINVAL;
267 }
268 xpram_devs = devs;
269
270
271
272
273
274 mem_needed = 0;
275 mem_auto_no = 0;
276 for (i = 0; i < xpram_devs; i++) {
277 if (sizes[i]) {
278 size = simple_strtoull(sizes[i], &sizes[i], 0);
279 switch (sizes[i][0]) {
280 case 'g':
281 case 'G':
282 size <<= 20;
283 break;
284 case 'm':
285 case 'M':
286 size <<= 10;
287 }
288 xpram_sizes[i] = (size + 3) & -4UL;
289 }
290 if (xpram_sizes[i])
291 mem_needed += xpram_sizes[i];
292 else
293 mem_auto_no++;
294 }
295
296 pr_info(" number of devices (partitions): %d \n", xpram_devs);
297 for (i = 0; i < xpram_devs; i++) {
298 if (xpram_sizes[i])
299 pr_info(" size of partition %d: %u kB\n",
300 i, xpram_sizes[i]);
301 else
302 pr_info(" size of partition %d to be set "
303 "automatically\n",i);
304 }
305 pr_info(" memory needed (for sized partitions): %lu kB\n",
306 mem_needed);
307 pr_info(" partitions to be sized automatically: %d\n",
308 mem_auto_no);
309
310 if (mem_needed > pages * 4) {
311 pr_err("Not enough expanded memory available\n");
312 return -EINVAL;
313 }
314
315
316
317
318
319
320
321 if (mem_auto_no) {
322 mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
323 pr_info(" automatically determined "
324 "partition size: %lu kB\n", mem_auto);
325 for (i = 0; i < xpram_devs; i++)
326 if (xpram_sizes[i] == 0)
327 xpram_sizes[i] = mem_auto;
328 }
329 return 0;
330}
331
332static int __init xpram_setup_blkdev(void)
333{
334 unsigned long offset;
335 int i, rc = -ENOMEM;
336
337 for (i = 0; i < xpram_devs; i++) {
338 xpram_disks[i] = alloc_disk(1);
339 if (!xpram_disks[i])
340 goto out;
341 xpram_queues[i] = blk_alloc_queue(GFP_KERNEL);
342 if (!xpram_queues[i]) {
343 put_disk(xpram_disks[i]);
344 goto out;
345 }
346 blk_queue_make_request(xpram_queues[i], xpram_make_request);
347 blk_queue_logical_block_size(xpram_queues[i], 4096);
348 }
349
350
351
352
353 rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
354 if (rc < 0)
355 goto out;
356
357
358
359
360 offset = 0;
361 for (i = 0; i < xpram_devs; i++) {
362 struct gendisk *disk = xpram_disks[i];
363
364 xpram_devices[i].size = xpram_sizes[i] / 4;
365 xpram_devices[i].offset = offset;
366 offset += xpram_devices[i].size;
367 disk->major = XPRAM_MAJOR;
368 disk->first_minor = i;
369 disk->fops = &xpram_devops;
370 disk->private_data = &xpram_devices[i];
371 disk->queue = xpram_queues[i];
372 sprintf(disk->disk_name, "slram%d", i);
373 set_capacity(disk, xpram_sizes[i] << 1);
374 add_disk(disk);
375 }
376
377 return 0;
378out:
379 while (i--) {
380 blk_cleanup_queue(xpram_queues[i]);
381 put_disk(xpram_disks[i]);
382 }
383 return rc;
384}
385
386
387
388
389static void xpram_resume_error(const char *message)
390{
391 pr_err("Resuming the system failed: %s\n", message);
392 panic("xpram resume error\n");
393}
394
395
396
397
398static int xpram_restore(struct device *dev)
399{
400 if (!xpram_pages)
401 return 0;
402 if (xpram_present() != 0)
403 xpram_resume_error("xpram disappeared");
404 if (xpram_pages != xpram_highest_page_index() + 1)
405 xpram_resume_error("Size of xpram changed");
406 return 0;
407}
408
409static const struct dev_pm_ops xpram_pm_ops = {
410 .restore = xpram_restore,
411};
412
413static struct platform_driver xpram_pdrv = {
414 .driver = {
415 .name = XPRAM_NAME,
416 .owner = THIS_MODULE,
417 .pm = &xpram_pm_ops,
418 },
419};
420
421static struct platform_device *xpram_pdev;
422
423
424
425
426static void __exit xpram_exit(void)
427{
428 int i;
429 for (i = 0; i < xpram_devs; i++) {
430 del_gendisk(xpram_disks[i]);
431 blk_cleanup_queue(xpram_queues[i]);
432 put_disk(xpram_disks[i]);
433 }
434 unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
435 platform_device_unregister(xpram_pdev);
436 platform_driver_unregister(&xpram_pdrv);
437}
438
439static int __init xpram_init(void)
440{
441 int rc;
442
443
444 if (xpram_present() != 0) {
445 pr_err("No expanded memory available\n");
446 return -ENODEV;
447 }
448 xpram_pages = xpram_highest_page_index() + 1;
449 pr_info(" %u pages expanded memory found (%lu KB).\n",
450 xpram_pages, (unsigned long) xpram_pages*4);
451 rc = xpram_setup_sizes(xpram_pages);
452 if (rc)
453 return rc;
454 rc = platform_driver_register(&xpram_pdrv);
455 if (rc)
456 return rc;
457 xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0);
458 if (IS_ERR(xpram_pdev)) {
459 rc = PTR_ERR(xpram_pdev);
460 goto fail_platform_driver_unregister;
461 }
462 rc = xpram_setup_blkdev();
463 if (rc)
464 goto fail_platform_device_unregister;
465 return 0;
466
467fail_platform_device_unregister:
468 platform_device_unregister(xpram_pdev);
469fail_platform_driver_unregister:
470 platform_driver_unregister(&xpram_pdrv);
471 return rc;
472}
473
474module_init(xpram_init);
475module_exit(xpram_exit);
476