2 * NVRAM variable manipulation (Linux kernel half)
4 * Copyright 2006, Broadcom Corporation
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.
12 * $Id: nvram_linux.c,v 1.19 2006/04/08 07:12:42 honor Exp $
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>
26 #include <linux/miscdevice.h>
27 #include <linux/mtd/mtd.h>
28 #include <asm/addrspace.h>
30 #include <asm/uaccess.h>
34 #include <bcmendian.h>
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)));
47 #define early_nvram_get(name) nvram_get(name)
51 /* Global SB handle */
52 extern void *bcm947xx_sbh;
53 extern spinlock_t bcm947xx_sbh_lock;
56 extern char *cfe_env_get(char *nv_buf, const char *name);
59 #define sbh bcm947xx_sbh
60 #define sbh_lock bcm947xx_sbh_lock
62 #define MB * 1024 * 1024
64 /* Probe for NVRAM header */
66 early_nvram_init(void)
68 struct nvram_header *header;
70 struct sflash *info = NULL;
72 uint32 base, off, lim;
75 if ((cc = sb_setcore(sbh, SB_CC, 0)) != NULL) {
76 base = KSEG1ADDR(SB_FLASH2);
77 switch (readl(&cc->capabilities) & CC_CAP_FLASH_MASK) {
84 if ((info = sflash_init(sbh,cc)) == NULL)
94 /* extif assumed, Stop at 4 MB */
95 base = KSEG1ADDR(SB_FLASH1);
99 /* XXX: hack for supporting the CFE environment stuff on WGT634U */
100 src = (u32 *) KSEG1ADDR(base + 8 * 1024 * 1024 - 0x2000);
101 dst = (u32 *) nvram_buf;
102 if ((lim == 0x02000000) && ((*src & 0xff00ff) == 0x000001)) {
103 printk("early_nvram_init: WGT634U NVRAM found.\n");
105 for (i = 0; i < 0x1ff0; i++) {
106 if (*src == 0xFFFFFFFF)
116 /* Windowed flash access */
117 header = (struct nvram_header *) KSEG1ADDR(base + off - NVRAM_SPACE);
118 if (header->magic == NVRAM_MAGIC)
123 /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
124 header = (struct nvram_header *) KSEG1ADDR(base + 4 KB);
125 if (header->magic == NVRAM_MAGIC)
128 header = (struct nvram_header *) KSEG1ADDR(base + 1 KB);
129 if (header->magic == NVRAM_MAGIC)
132 printk("early_nvram_init: NVRAM not found\n");
136 src = (u32 *) header;
137 dst = (u32 *) nvram_buf;
138 for (i = 0; i < sizeof(struct nvram_header); i += 4)
140 for (; i < header->len && i < NVRAM_SPACE; i += 4)
141 *dst++ = ltoh32(*src++);
144 /* Early (before mm or mtd) read-only access to NVRAM */
146 early_nvram_get(const char *name)
148 char *var, *value, *end, *eq;
161 return cfe_env_get(nvram_buf, name);
163 /* Look for name=value and return value */
164 var = &nvram_buf[sizeof(struct nvram_header)];
165 end = nvram_buf + sizeof(nvram_buf) - 2;
166 end[0] = end[1] = '\0';
167 for (; *var; var = value + strlen(value) + 1) {
168 if (!(eq = strchr(var, '=')))
171 if ((eq - var) == strlen(name) && strncmp(var, name, (eq - var)) == 0)
179 early_nvram_getall(char *buf, int count)
193 /* Write name=value\0 ... \0\0 */
194 var = &nvram_buf[sizeof(struct nvram_header)];
195 end = nvram_buf + sizeof(nvram_buf) - 2;
196 end[0] = end[1] = '\0';
197 for (; *var; var += strlen(var) + 1) {
198 if ((count - len) <= (strlen(var) + 1))
200 len += sprintf(buf + len, "%s", var) + 1;
207 extern char * _nvram_get(const char *name);
208 extern int _nvram_set(const char *name, const char *value);
209 extern int _nvram_unset(const char *name);
210 extern int _nvram_getall(char *buf, int count);
211 extern int _nvram_commit(struct nvram_header *header);
212 extern int _nvram_init(void *sbh);
213 extern void _nvram_exit(void);
216 static spinlock_t nvram_lock = SPIN_LOCK_UNLOCKED;
217 static struct semaphore nvram_sem;
218 static unsigned long nvram_offset = 0;
219 static int nvram_major = -1;
220 static devfs_handle_t nvram_handle = NULL;
221 static struct mtd_info *nvram_mtd = NULL;
224 _nvram_read(char *buf)
226 struct nvram_header *header = (struct nvram_header *) buf;
230 MTD_READ(nvram_mtd, nvram_mtd->size - NVRAM_SPACE, NVRAM_SPACE, &len, buf) ||
231 len != NVRAM_SPACE ||
232 header->magic != NVRAM_MAGIC) {
233 /* Maybe we can recover some data from early initialization */
234 memcpy(buf, nvram_buf, NVRAM_SPACE);
241 _nvram_realloc(struct nvram_tuple *t, const char *name, const char *value)
243 if ((nvram_offset + strlen(value) + 1) > NVRAM_SPACE)
247 if (!(t = kmalloc(sizeof(struct nvram_tuple) + strlen(name) + 1, GFP_ATOMIC)))
251 t->name = (char *) &t[1];
252 strcpy(t->name, name);
258 if (!t->value || strcmp(t->value, value)) {
259 t->value = &nvram_buf[nvram_offset];
260 strcpy(t->value, value);
261 nvram_offset += strlen(value) + 1;
268 _nvram_free(struct nvram_tuple *t)
277 nvram_set(const char *name, const char *value)
281 struct nvram_header *header;
283 spin_lock_irqsave(&nvram_lock, flags);
284 if ((ret = _nvram_set(name, value))) {
285 /* Consolidate space and try again */
286 if ((header = kmalloc(NVRAM_SPACE, GFP_ATOMIC))) {
287 if (_nvram_commit(header) == 0)
288 ret = _nvram_set(name, value);
292 spin_unlock_irqrestore(&nvram_lock, flags);
298 real_nvram_get(const char *name)
303 spin_lock_irqsave(&nvram_lock, flags);
304 value = _nvram_get(name);
305 spin_unlock_irqrestore(&nvram_lock, flags);
311 nvram_get(const char *name)
313 if (nvram_major >= 0)
314 return real_nvram_get(name);
316 return early_nvram_get(name);
320 nvram_unset(const char *name)
325 spin_lock_irqsave(&nvram_lock, flags);
326 ret = _nvram_unset(name);
327 spin_unlock_irqrestore(&nvram_lock, flags);
333 erase_callback(struct erase_info *done)
335 wait_queue_head_t *wait_q = (wait_queue_head_t *) done->priv;
343 size_t erasesize, len, magic_len;
346 struct nvram_header *header;
349 DECLARE_WAITQUEUE(wait, current);
350 wait_queue_head_t wait_q;
351 struct erase_info erase;
352 u_int32_t magic_offset = 0; /* Offset for writing MAGIC # */
355 printk("nvram_commit: NVRAM not found\n");
359 if (in_interrupt()) {
360 printk("nvram_commit: not committing in interrupt\n");
364 /* Backup sector blocks to be erased */
365 erasesize = ROUNDUP(NVRAM_SPACE, nvram_mtd->erasesize);
366 if (!(buf = kmalloc(erasesize, GFP_KERNEL))) {
367 printk("nvram_commit: out of memory\n");
373 if ((i = erasesize - NVRAM_SPACE) > 0) {
374 offset = nvram_mtd->size - erasesize;
376 ret = MTD_READ(nvram_mtd, offset, i, &len, buf);
377 if (ret || len != i) {
378 printk("nvram_commit: read error ret = %d, len = %d/%d\n", ret, len, i);
382 header = (struct nvram_header *)(buf + i);
383 magic_offset = i + ((void *)&header->magic - (void *)header);
385 offset = nvram_mtd->size - NVRAM_SPACE;
386 magic_offset = ((void *)&header->magic - (void *)header);
387 header = (struct nvram_header *)buf;
390 /* clear the existing magic # to mark the NVRAM as unusable
391 we can pull MAGIC bits low without erase */
392 header->magic = NVRAM_CLEAR_MAGIC; /* All zeros magic */
394 /* Unlock sector blocks (for Intel 28F320C3B flash) , 20060309 */
395 if(nvram_mtd->unlock)
396 nvram_mtd->unlock(nvram_mtd, offset, nvram_mtd->erasesize);
398 ret = MTD_WRITE(nvram_mtd, offset + magic_offset, sizeof(header->magic),
399 &magic_len, (char *)&header->magic);
400 if (ret || magic_len != sizeof(header->magic)) {
401 printk("nvram_commit: clear MAGIC error\n");
406 header->magic = NVRAM_MAGIC; /* reset MAGIC before we regenerate the NVRAM,
407 otherwise we'll have an incorrect CRC */
408 /* Regenerate NVRAM */
409 spin_lock_irqsave(&nvram_lock, flags);
410 ret = _nvram_commit(header);
411 spin_unlock_irqrestore(&nvram_lock, flags);
415 /* Erase sector blocks */
416 init_waitqueue_head(&wait_q);
417 for (; offset < nvram_mtd->size - NVRAM_SPACE + header->len; offset += nvram_mtd->erasesize) {
418 erase.mtd = nvram_mtd;
420 erase.len = nvram_mtd->erasesize;
421 erase.callback = erase_callback;
422 erase.priv = (u_long) &wait_q;
424 set_current_state(TASK_INTERRUPTIBLE);
425 add_wait_queue(&wait_q, &wait);
427 /* Unlock sector blocks */
428 if (nvram_mtd->unlock)
429 nvram_mtd->unlock(nvram_mtd, offset, nvram_mtd->erasesize);
431 if ((ret = MTD_ERASE(nvram_mtd, &erase))) {
432 set_current_state(TASK_RUNNING);
433 remove_wait_queue(&wait_q, &wait);
434 printk("nvram_commit: erase error\n");
438 /* Wait for erase to finish */
440 remove_wait_queue(&wait_q, &wait);
443 /* Write partition up to end of data area */
444 header->magic = NVRAM_INVALID_MAGIC; /* All ones magic */
445 offset = nvram_mtd->size - erasesize;
446 i = erasesize - NVRAM_SPACE + header->len;
447 ret = MTD_WRITE(nvram_mtd, offset, i, &len, buf);
448 if (ret || len != i) {
449 printk("nvram_commit: write error\n");
454 /* Now mark the NVRAM in flash as "valid" by setting the correct
456 header->magic = NVRAM_MAGIC;
457 ret = MTD_WRITE(nvram_mtd, offset + magic_offset, sizeof(header->magic),
458 &magic_len, (char *)&header->magic);
459 if (ret || magic_len != sizeof(header->magic)) {
460 printk("nvram_commit: write MAGIC error\n");
466 * Reading a few bytes back here will put the device
467 * back to the correct mode on certain flashes */
468 offset = nvram_mtd->size - erasesize;
469 ret = MTD_READ(nvram_mtd, offset, 4, &len, buf);
479 nvram_getall(char *buf, int count)
484 spin_lock_irqsave(&nvram_lock, flags);
485 if (nvram_major >= 0)
486 ret = _nvram_getall(buf, count);
488 ret = early_nvram_getall(buf, count);
489 spin_unlock_irqrestore(&nvram_lock, flags);
500 /* User mode interface below */
503 dev_nvram_read(struct file *file, char *buf, size_t count, loff_t *ppos)
505 char tmp[100], *name = tmp, *value;
509 if (count > sizeof(tmp)) {
510 if (!(name = kmalloc(count, GFP_KERNEL)))
514 if (copy_from_user(name, buf, count)) {
520 /* Get all variables */
521 ret = nvram_getall(name, count);
523 if (copy_to_user(buf, name, count)) {
530 if (!(value = nvram_get(name))) {
535 /* Provide the offset into mmap() space */
536 off = (unsigned long) value - (unsigned long) nvram_buf;
538 if (put_user(off, (unsigned long *) buf)) {
543 ret = sizeof(unsigned long);
556 dev_nvram_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
558 char tmp[100], *name = tmp, *value;
561 if (count > sizeof(tmp)) {
562 if (!(name = kmalloc(count, GFP_KERNEL)))
566 if (copy_from_user(name, buf, count)) {
572 name = strsep(&value, "=");
574 ret = nvram_set(name, value) ? : count;
576 ret = nvram_unset(name) ? : count;
586 dev_nvram_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
588 if (cmd != NVRAM_MAGIC)
591 return nvram_commit();
595 dev_nvram_mmap(struct file *file, struct vm_area_struct *vma)
597 unsigned long offset = virt_to_phys(nvram_buf);
599 if (remap_page_range(vma->vm_start, offset, vma->vm_end-vma->vm_start,
607 dev_nvram_open(struct inode *inode, struct file * file)
614 dev_nvram_release(struct inode *inode, struct file * file)
620 static struct file_operations dev_nvram_fops = {
622 open: dev_nvram_open,
623 release: dev_nvram_release,
624 read: dev_nvram_read,
625 write: dev_nvram_write,
626 ioctl: dev_nvram_ioctl,
627 mmap: dev_nvram_mmap,
634 struct page *page, *end;
637 devfs_unregister(nvram_handle);
639 if (nvram_major >= 0)
640 devfs_unregister_chrdev(nvram_major, "nvram");
643 put_mtd_device(nvram_mtd);
645 while ((PAGE_SIZE << order) < NVRAM_SPACE)
647 end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
648 for (page = virt_to_page(nvram_buf); page <= end; page++)
649 mem_map_unreserve(page);
657 int order = 0, ret = 0;
658 struct page *page, *end;
661 /* Allocate and reserve memory to mmap() */
662 while ((PAGE_SIZE << order) < NVRAM_SPACE)
664 end = virt_to_page(nvram_buf + (PAGE_SIZE << order) - 1);
665 for (page = virt_to_page(nvram_buf); page <= end; page++)
666 mem_map_reserve(page);
669 /* Find associated MTD device */
670 for (i = 0; i < MAX_MTD_DEVICES; i++) {
671 nvram_mtd = get_mtd_device(NULL, i);
673 if (!strcmp(nvram_mtd->name, "nvram") &&
674 nvram_mtd->size >= NVRAM_SPACE)
676 put_mtd_device(nvram_mtd);
679 if (i >= MAX_MTD_DEVICES)
683 /* Initialize hash table lock */
684 spin_lock_init(&nvram_lock);
686 /* Initialize commit semaphore */
687 init_MUTEX(&nvram_sem);
689 /* Register char device */
690 if ((nvram_major = devfs_register_chrdev(0, "nvram", &dev_nvram_fops)) < 0) {
695 /* Initialize hash table */
698 /* Create /dev/nvram handle */
699 nvram_handle = devfs_register(NULL, "nvram", DEVFS_FL_NONE, nvram_major, 0,
700 S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP, &dev_nvram_fops, NULL);
702 /* Set the SDRAM NCDL value into NVRAM if not already done */
703 if (getintvar(NULL, "sdram_ncdl") == 0) {
705 char buf[] = "0x00000000";
707 if ((ncdl = sb_memc_get_ncdl(sbh))) {
708 sprintf(buf, "0x%08x", ncdl);
709 nvram_set("sdram_ncdl", buf);
721 module_init(dev_nvram_init);
722 module_exit(dev_nvram_exit);