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[openwrt.git] / package / linux / kernel-source / arch / mips / brcm-boards / bcm947xx / nvram_linux.c
1 /*
2 * NVRAM variable manipulation (Linux kernel half)
3 *
4 * Copyright 2004, Broadcom Corporation
5 * All Rights Reserved.
6 *
7 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
8 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
9 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
10 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
11 *
12 * $Id$
13 */
14
15 #include <linux/config.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/interrupt.h>
21 #include <linux/spinlock.h>
22 #include <linux/slab.h>
23 #include <linux/bootmem.h>
24 #include <linux/wrapper.h>
25 #include <linux/fs.h>
26 #include <linux/miscdevice.h>
27 #include <linux/mtd/mtd.h>
28 #include <asm/addrspace.h>
29 #include <asm/io.h>
30 #include <asm/uaccess.h>
31
32 #include <typedefs.h>
33 #include <bcmendian.h>
34 #include <bcmnvram.h>
35 #include <bcmutils.h>
36 #include <sbconfig.h>
37 #include <sbchipc.h>
38 #include <sbutils.h>
39 #include <sbmips.h>
40 #include <sflash.h>
41
42 /* In BSS to minimize text size and page aligned so it can be mmap()-ed */
43 static char nvram_buf[NVRAM_SPACE] __attribute__((aligned(PAGE_SIZE)));
44
45 #ifdef MODULE
46
47 #define early_nvram_get(name) nvram_get(name)
48
49 #else /* !MODULE */
50
51 /* Global SB handle */
52 extern void *bcm947xx_sbh;
53 extern spinlock_t bcm947xx_sbh_lock;
54
55 /* Convenience */
56 #define sbh bcm947xx_sbh
57 #define sbh_lock bcm947xx_sbh_lock
58 #define KB * 1024
59 #define MB * 1024 * 1024
60
61 /* Probe for NVRAM header */
62 static void __init
63 early_nvram_init(void)
64 {
65 struct nvram_header *header;
66 chipcregs_t *cc;
67 struct sflash *info = NULL;
68 int i;
69 uint32 base, off, lim;
70
71 if ((cc = sb_setcore(sbh, SB_CC, 0)) != NULL) {
72 base = CC_FLASH_BASE;
73 switch (readl(&cc->capabilities) & CAP_FLASH_MASK) {
74 case PFLASH:
75 lim = CC_FLASH_MAX;
76 break;
77
78 case SFLASH_ST:
79 case SFLASH_AT:
80 if ((info = sflash_init(cc)) == NULL)
81 return;
82 lim = info->size;
83 break;
84
85 case FLASH_NONE:
86 default:
87 return;
88 }
89 } else {
90 /* extif assumed, Stop at 4 MB */
91 base = FLASH_BASE;
92 lim = FLASH_MAX;
93 }
94
95 off = FLASH_MIN;
96 while (off <= lim) {
97 /* Windowed flash access */
98 header = (struct nvram_header *) KSEG1ADDR(base + off - NVRAM_SPACE);
99 if (header->magic == NVRAM_MAGIC) {
100 u32 *src = (u32 *) header;
101 u32 *dst = (u32 *) nvram_buf;
102 for (i = 0; i < sizeof(struct nvram_header); i += 4)
103 *dst++ = *src++;
104 for (; i < header->len && i < NVRAM_SPACE; i += 4)
105 *dst++ = ltoh32(*src++);
106 return;
107 }
108
109 /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
110 if (off == 1 KB)
111 break;
112 else if (off == 4 KB)
113 off = 1 KB;
114 else if (off == lim)
115 off = 4 KB;
116 else
117 off <<= 1;
118 }
119 }
120
121 /* Early (before mm or mtd) read-only access to NVRAM */
122 static char * __init
123 early_nvram_get(const char *name)
124 {
125 char *var, *value, *end, *eq;
126
127 if (!name)
128 return NULL;
129
130 if (!nvram_buf[0])
131 early_nvram_init();
132
133 /* Look for name=value and return value */
134 var = &nvram_buf[sizeof(struct nvram_header)];
135 end = nvram_buf + sizeof(nvram_buf) - 2;
136 end[0] = end[1] = '\0';
137 for (; *var; var = value + strlen(value) + 1) {
138 if (!(eq = strchr(var, '=')))
139 break;
140 value = eq + 1;
141 if ((eq - var) == strlen(name) && strncmp(var, name, (eq - var)) == 0)
142 return value;
143 }
144
145 return NULL;
146 }
147
148 #endif /* !MODULE */
149
150 extern char * _nvram_get(const char *name);
151 extern int _nvram_set(const char *name, const char *value);
152 extern int _nvram_unset(const char *name);
153 extern int _nvram_getall(char *buf, int count);
154 extern int _nvram_commit(struct nvram_header *header);
155 extern int _nvram_init(void);
156 extern void _nvram_exit(void);
157
158 /* Globals */
159 static spinlock_t nvram_lock = SPIN_LOCK_UNLOCKED;
160 static struct semaphore nvram_sem;
161 static unsigned long nvram_offset = 0;
162 static int nvram_major = -1;
163 static devfs_handle_t nvram_handle = NULL;
164 static struct mtd_info *nvram_mtd = NULL;
165
166 int
167 _nvram_read(char *buf)
168 {
169 struct nvram_header *header = (struct nvram_header *) buf;
170 size_t len;
171
172 if (!nvram_mtd ||
173 MTD_READ(nvram_mtd, nvram_mtd->size - NVRAM_SPACE, NVRAM_SPACE, &len, buf) ||
174 len != NVRAM_SPACE ||
175 header->magic != NVRAM_MAGIC) {
176 /* Maybe we can recover some data from early initialization */
177 memcpy(buf, nvram_buf, NVRAM_SPACE);
178 }
179
180 return 0;
181 }
182
183 struct nvram_tuple *
184 _nvram_realloc(struct nvram_tuple *t, const char *name, const char *value)
185 {
186 if ((nvram_offset + strlen(value) + 1) > NVRAM_SPACE)
187 return NULL;
188
189 if (!t) {
190 if (!(t = kmalloc(sizeof(struct nvram_tuple) + strlen(name) + 1, GFP_ATOMIC)))
191 return NULL;
192
193 /* Copy name */
194 t->name = (char *) &t[1];
195 strcpy(t->name, name);
196
197 t->value = NULL;
198 }
199
200 /* Copy value */
201 if (!t->value || strcmp(t->value, value)) {
202 t->value = &nvram_buf[nvram_offset];
203 strcpy(t->value, value);
204 nvram_offset += strlen(value) + 1;
205 }
206
207 return t;
208 }
209
210 void
211 _nvram_free(struct nvram_tuple *t)
212 {
213 if (!t)
214 nvram_offset = 0;
215 else
216 kfree(t);
217 }
218
219 int
220 nvram_set(const char *name, const char *value)
221 {
222 unsigned long flags;
223 int ret;
224 struct nvram_header *header;
225
226 spin_lock_irqsave(&nvram_lock, flags);
227 if ((ret = _nvram_set(name, value))) {
228 /* Consolidate space and try again */
229 if ((header = kmalloc(NVRAM_SPACE, GFP_ATOMIC))) {
230 if (_nvram_commit(header) == 0)
231 ret = _nvram_set(name, value);
232 kfree(header);
233 }
234 }
235 spin_unlock_irqrestore(&nvram_lock, flags);
236
237 return ret;
238 }
239
240 char *
241 real_nvram_get(const char *name)
242 {
243 unsigned long flags;
244 char *value;
245
246 spin_lock_irqsave(&nvram_lock, flags);
247 value = _nvram_get(name);
248 spin_unlock_irqrestore(&nvram_lock, flags);
249
250 return value;
251 }
252
253 char *
254 nvram_get(const char *name)
255 {
256 if (nvram_major >= 0)
257 return real_nvram_get(name);
258 else
259 return early_nvram_get(name);
260 }
261
262 int
263 nvram_unset(const char *name)
264 {
265 unsigned long flags;
266 int ret;
267
268 spin_lock_irqsave(&nvram_lock, flags);
269 ret = _nvram_unset(name);
270 spin_unlock_irqrestore(&nvram_lock, flags);
271
272 return ret;
273 }
274
275 static void
276 erase_callback(struct erase_info *done)
277 {
278 wait_queue_head_t *wait_q = (wait_queue_head_t *) done->priv;
279 wake_up(wait_q);
280 }
281
282 int
283 nvram_commit(void)
284 {
285 char *buf;
286 size_t erasesize, len;
287 unsigned int i;
288 int ret;
289 struct nvram_header *header;
290 unsigned long flags;
291 u_int32_t offset;
292 DECLARE_WAITQUEUE(wait, current);
293 wait_queue_head_t wait_q;
294 struct erase_info erase;
295
296 printk("nvram_commit(): init\n");
297
298 if (!nvram_mtd) {
299 printk("nvram_commit: NVRAM not found\n");
300 return -ENODEV;
301 }
302
303 if (in_interrupt()) {
304 printk("nvram_commit: not committing in interrupt\n");
305 return -EINVAL;
306 }
307
308 /* Backup sector blocks to be erased */
309 erasesize = ROUNDUP(NVRAM_SPACE, nvram_mtd->erasesize);
310 if (!(buf = kmalloc(erasesize, GFP_KERNEL))) {
311 printk("nvram_commit: out of memory\n");
312 return -ENOMEM;
313 }
314
315 down(&nvram_sem);
316 #if 0
317 offset = nvram_mtd->size - erasesize;
318 i = erasesize - NVRAM_SPACE;
319 ret = MTD_READ(nvram_mtd, offset, i, &len, buf);
320 if (ret || len != i) {
321 printk("nvram_commit: read error\n");
322 ret = -EIO;
323 goto done;
324 #endif
325 if ((i = erasesize - NVRAM_SPACE) > 0) {
326 offset = nvram_mtd->size - erasesize;
327 len = 0;
328 ret = MTD_READ(nvram_mtd, offset, i, &len, buf);
329 if (ret || len != i) {
330 printk("nvram_commit: read error ret = %d, len = %d/%d\n", ret, len, i);
331 ret = -EIO;
332 goto done;
333 }
334 header = (struct nvram_header *)(buf + i);
335 } else {
336 offset = nvram_mtd->size - NVRAM_SPACE;
337 header = (struct nvram_header *)buf;
338 }
339
340 /* Regenerate NVRAM */
341 spin_lock_irqsave(&nvram_lock, flags);
342 ret = _nvram_commit(header);
343 spin_unlock_irqrestore(&nvram_lock, flags);
344 if (ret)
345 goto done;
346
347 /* Erase sector blocks */
348 init_waitqueue_head(&wait_q);
349 for (; offset < nvram_mtd->size - NVRAM_SPACE + header->len; offset += nvram_mtd->erasesize) {
350 erase.mtd = nvram_mtd;
351 erase.addr = offset;
352 erase.len = nvram_mtd->erasesize;
353 erase.callback = erase_callback;
354 erase.priv = (u_long) &wait_q;
355
356 set_current_state(TASK_INTERRUPTIBLE);
357 add_wait_queue(&wait_q, &wait);
358
359 /* Unlock sector blocks */
360 if (nvram_mtd->unlock)
361 nvram_mtd->unlock(nvram_mtd, offset, nvram_mtd->erasesize);
362
363 if ((ret = MTD_ERASE(nvram_mtd, &erase))) {
364 set_current_state(TASK_RUNNING);
365 remove_wait_queue(&wait_q, &wait);
366 printk("nvram_commit: erase error\n");
367 goto done;
368 }
369
370 /* Wait for erase to finish */
371 schedule();
372 remove_wait_queue(&wait_q, &wait);
373 }
374
375 /* Write partition up to end of data area */
376 offset = nvram_mtd->size - erasesize;
377 i = erasesize - NVRAM_SPACE + header->len;
378 ret = MTD_WRITE(nvram_mtd, offset, i, &len, buf);
379 if (ret || len != i) {
380 printk("nvram_commit: write error\n");
381 ret = -EIO;
382 goto done;
383 }
384 /*
385 * Reading a few bytes back here will put the device
386 * back to the correct mode on certain flashes */
387
388 offset = nvram_mtd->size - erasesize;
389 ret = MTD_READ(nvram_mtd, offset, 4, &len, buf);
390
391 done:
392 up(&nvram_sem);
393 kfree(buf);
394 printk("nvram_commit(): end\n");
395 return ret;
396 }
397
398 int
399 nvram_getall(char *buf, int count)
400 {
401 unsigned long flags;
402 int ret;
403
404 spin_lock_irqsave(&nvram_lock, flags);
405 ret = _nvram_getall(buf, count);
406 spin_unlock_irqrestore(&nvram_lock, flags);
407
408 return ret;
409 }
410
411 EXPORT_SYMBOL(nvram_get);
412 EXPORT_SYMBOL(nvram_getall);
413 EXPORT_SYMBOL(nvram_set);
414 EXPORT_SYMBOL(nvram_unset);
415 EXPORT_SYMBOL(nvram_commit);
416
417 /* User mode interface below */
418
419 static ssize_t
420 dev_nvram_read(struct file *file, char *buf, size_t count, loff_t *ppos)
421 {
422 char tmp[100], *name = tmp, *value;
423 ssize_t ret;
424 unsigned long off;
425
426 if (count > sizeof(tmp)) {
427 if (!(name = kmalloc(count, GFP_KERNEL)))
428 return -ENOMEM;
429 }
430
431 if (copy_from_user(name, buf, count)) {
432 ret = -EFAULT;
433 goto done;
434 }
435
436 if (*name == '\0') {
437 /* Get all variables */
438 ret = nvram_getall(name, count);
439 if (ret == 0) {
440 if (copy_to_user(buf, name, count)) {
441 ret = -EFAULT;
442 goto done;
443 }
444 ret = count;
445 }
446 } else {
447 if (!(value = nvram_get(name))) {
448 ret = 0;
449 goto done;
450 }
451
452 /* Provide the offset into mmap() space */
453 off = (unsigned long) value - (unsigned long) nvram_buf;
454
455 if (put_user(off, (unsigned long *) buf)) {
456 ret = -EFAULT;
457 goto done;
458 }
459
460 ret = sizeof(unsigned long);
461 }
462
463 flush_cache_all();
464
465 done:
466 if (name != tmp)
467 kfree(name);
468
469 return ret;
470 }
471
472 static ssize_t
473 dev_nvram_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
474 {
475 char tmp[100], *name = tmp, *value;
476 ssize_t ret;
477
478 if (count > sizeof(tmp)) {
479 if (!(name = kmalloc(count, GFP_KERNEL)))
480 return -ENOMEM;
481 }
482
483 if (copy_from_user(name, buf, count)) {
484 ret = -EFAULT;
485 goto done;
486 }
487
488 value = name;
489 name = strsep(&value, "=");
490 if (value)
491 ret = nvram_set(name, value) ? : count;
492 else
493 ret = nvram_unset(name) ? : count;
494
495 done:
496 if (name != tmp)
497 kfree(name);
498
499 return ret;
500 }
501
502 static int
503 dev_nvram_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
504 {
505 if (cmd != NVRAM_MAGIC)
506 return -EINVAL;
507 return nvram_commit();
508 }
509
510 static int
511 dev_nvram_mmap(struct file *file, struct vm_area_struct *vma)
512 {
513 unsigned long offset = virt_to_phys(nvram_buf);
514
515 if (remap_page_range(vma->vm_start, offset, vma->vm_end-vma->vm_start,
516 vma->vm_page_prot))
517 return -EAGAIN;
518
519 return 0;
520 }
521
522 static int
523 dev_nvram_open(struct inode *inode, struct file * file)
524 {
525 MOD_INC_USE_COUNT;
526 return 0;
527 }
528
529 static int
530 dev_nvram_release(struct inode *inode, struct file * file)
531 {
532 MOD_DEC_USE_COUNT;
533 return 0;
534 }
535
536 static struct file_operations dev_nvram_fops = {
537 owner: THIS_MODULE,
538 open: dev_nvram_open,
539 release: dev_nvram_release,
540 read: dev_nvram_read,
541 write: dev_nvram_write,
542 ioctl: dev_nvram_ioctl,
543 mmap: dev_nvram_mmap,
544 };
545
546 static void
547 dev_nvram_exit(void)
548 {
549 int order = 0;
550 struct page *page, *end;
551
552 if (nvram_handle)
553 devfs_unregister(nvram_handle);
554
555 if (nvram_major >= 0)
556 devfs_unregister_chrdev(nvram_major, "nvram");
557
558 if (nvram_mtd)
559 put_mtd_device(nvram_mtd);
560
561 while ((PAGE_SIZE << order) < NVRAM_SPACE)
562 order++;
563 end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
564 for (page = virt_to_page(nvram_buf); page <= end; page++)
565 mem_map_unreserve(page);
566
567 _nvram_exit();
568 }
569
570 static int __init
571 dev_nvram_init(void)
572 {
573 int order = 0, ret = 0;
574 struct page *page, *end;
575 unsigned int i;
576
577 /* Allocate and reserve memory to mmap() */
578 while ((PAGE_SIZE << order) < NVRAM_SPACE)
579 order++;
580 end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
581 for (page = virt_to_page(nvram_buf); page <= end; page++)
582 mem_map_reserve(page);
583
584 #ifdef CONFIG_MTD
585 /* Find associated MTD device */
586 for (i = 0; i < MAX_MTD_DEVICES; i++) {
587 nvram_mtd = get_mtd_device(NULL, i);
588 if (nvram_mtd) {
589 if (!strcmp(nvram_mtd->name, "nvram") &&
590 nvram_mtd->size >= NVRAM_SPACE)
591 break;
592 put_mtd_device(nvram_mtd);
593 }
594 }
595 if (i >= MAX_MTD_DEVICES)
596 nvram_mtd = NULL;
597 #endif
598
599 /* Initialize hash table lock */
600 spin_lock_init(&nvram_lock);
601
602 /* Initialize commit semaphore */
603 init_MUTEX(&nvram_sem);
604
605 /* Register char device */
606 if ((nvram_major = devfs_register_chrdev(0, "nvram", &dev_nvram_fops)) < 0) {
607 ret = nvram_major;
608 goto err;
609 }
610
611 /* Initialize hash table */
612 _nvram_init();
613
614 /* Create /dev/nvram handle */
615 nvram_handle = devfs_register(NULL, "nvram", DEVFS_FL_NONE, nvram_major, 0,
616 S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP, &dev_nvram_fops, NULL);
617
618 /* Set the SDRAM NCDL value into NVRAM if not already done */
619 if (getintvar(NULL, "sdram_ncdl") == 0) {
620 unsigned int ncdl;
621 char buf[] = "0x00000000";
622
623 if ((ncdl = sb_memc_get_ncdl(sbh))) {
624 sprintf(buf, "0x%08x", ncdl);
625 nvram_set("sdram_ncdl", buf);
626 nvram_commit();
627 }
628 }
629
630 return 0;
631
632 err:
633 dev_nvram_exit();
634 return ret;
635 }
636
637 module_init(dev_nvram_init);
638 module_exit(dev_nvram_exit);
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