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linux-sg2042/arch/ppc64/kernel/nvram.c

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/*
* c 2001 PPC 64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* /dev/nvram driver for PPC64
*
* This perhaps should live in drivers/char
*
* TODO: Split the /dev/nvram part (that one can use
* drivers/char/generic_nvram.c) from the arch & partition
* parsing code.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/nvram.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <asm/nvram.h>
#include <asm/rtas.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/systemcfg.h>
#undef DEBUG_NVRAM
static int nvram_scan_partitions(void);
static int nvram_setup_partition(void);
static int nvram_create_os_partition(void);
static int nvram_remove_os_partition(void);
static struct nvram_partition * nvram_part;
static long nvram_error_log_index = -1;
static long nvram_error_log_size = 0;
int no_logging = 1; /* Until we initialize everything,
* make sure we don't try logging
* anything */
extern volatile int error_log_cnt;
struct err_log_info {
int error_type;
unsigned int seq_num;
};
static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
{
int size;
if (ppc_md.nvram_size == NULL)
return -ENODEV;
size = ppc_md.nvram_size();
switch (origin) {
case 1:
offset += file->f_pos;
break;
case 2:
offset += size;
break;
}
if (offset < 0)
return -EINVAL;
file->f_pos = offset;
return file->f_pos;
}
static ssize_t dev_nvram_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t len;
char *tmp_buffer;
int size;
if (ppc_md.nvram_size == NULL)
return -ENODEV;
size = ppc_md.nvram_size();
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
if (*ppos >= size)
return 0;
if (count > size)
count = size;
tmp_buffer = (char *) kmalloc(count, GFP_KERNEL);
if (!tmp_buffer) {
printk(KERN_ERR "dev_read_nvram: kmalloc failed\n");
return -ENOMEM;
}
len = ppc_md.nvram_read(tmp_buffer, count, ppos);
if ((long)len <= 0) {
kfree(tmp_buffer);
return len;
}
if (copy_to_user(buf, tmp_buffer, len)) {
kfree(tmp_buffer);
return -EFAULT;
}
kfree(tmp_buffer);
return len;
}
static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t len;
char * tmp_buffer;
int size;
if (ppc_md.nvram_size == NULL)
return -ENODEV;
size = ppc_md.nvram_size();
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
if (*ppos >= size)
return 0;
if (count > size)
count = size;
tmp_buffer = (char *) kmalloc(count, GFP_KERNEL);
if (!tmp_buffer) {
printk(KERN_ERR "dev_nvram_write: kmalloc failed\n");
return -ENOMEM;
}
if (copy_from_user(tmp_buffer, buf, count)) {
kfree(tmp_buffer);
return -EFAULT;
}
len = ppc_md.nvram_write(tmp_buffer, count, ppos);
if ((long)len <= 0) {
kfree(tmp_buffer);
return len;
}
kfree(tmp_buffer);
return len;
}
static int dev_nvram_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
switch(cmd) {
#ifdef CONFIG_PPC_PMAC
case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
case IOC_NVRAM_GET_OFFSET: {
int part, offset;
if (systemcfg->platform != PLATFORM_POWERMAC)
return -EINVAL;
if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
return -EFAULT;
if (part < pmac_nvram_OF || part > pmac_nvram_NR)
return -EINVAL;
offset = pmac_get_partition(part);
if (offset < 0)
return offset;
if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
return -EFAULT;
return 0;
}
#endif /* CONFIG_PPC_PMAC */
}
return -EINVAL;
}
struct file_operations nvram_fops = {
.owner = THIS_MODULE,
.llseek = dev_nvram_llseek,
.read = dev_nvram_read,
.write = dev_nvram_write,
.ioctl = dev_nvram_ioctl,
};
static struct miscdevice nvram_dev = {
NVRAM_MINOR,
"nvram",
&nvram_fops
};
#ifdef DEBUG_NVRAM
static void nvram_print_partitions(char * label)
{
struct list_head * p;
struct nvram_partition * tmp_part;
printk(KERN_WARNING "--------%s---------\n", label);
printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
list_for_each(p, &nvram_part->partition) {
tmp_part = list_entry(p, struct nvram_partition, partition);
printk(KERN_WARNING "%d \t%02x\t%02x\t%d\t%s\n",
tmp_part->index, tmp_part->header.signature,
tmp_part->header.checksum, tmp_part->header.length,
tmp_part->header.name);
}
}
#endif
static int nvram_write_header(struct nvram_partition * part)
{
loff_t tmp_index;
int rc;
tmp_index = part->index;
rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index);
return rc;
}
static unsigned char nvram_checksum(struct nvram_header *p)
{
unsigned int c_sum, c_sum2;
unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
/* The sum may have spilled into the 3rd byte. Fold it back. */
c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
/* The sum cannot exceed 2 bytes. Fold it into a checksum */
c_sum2 = (c_sum >> 8) + (c_sum << 8);
c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
return c_sum;
}
/*
* Find an nvram partition, sig can be 0 for any
* partition or name can be NULL for any name, else
* tries to match both
*/
struct nvram_partition *nvram_find_partition(int sig, const char *name)
{
struct nvram_partition * part;
struct list_head * p;
list_for_each(p, &nvram_part->partition) {
part = list_entry(p, struct nvram_partition, partition);
if (sig && part->header.signature != sig)
continue;
if (name && 0 != strncmp(name, part->header.name, 12))
continue;
return part;
}
return NULL;
}
EXPORT_SYMBOL(nvram_find_partition);
static int nvram_remove_os_partition(void)
{
struct list_head *i;
struct list_head *j;
struct nvram_partition * part;
struct nvram_partition * cur_part;
int rc;
list_for_each(i, &nvram_part->partition) {
part = list_entry(i, struct nvram_partition, partition);
if (part->header.signature != NVRAM_SIG_OS)
continue;
/* Make os partition a free partition */
part->header.signature = NVRAM_SIG_FREE;
sprintf(part->header.name, "wwwwwwwwwwww");
part->header.checksum = nvram_checksum(&part->header);
/* Merge contiguous free partitions backwards */
list_for_each_prev(j, &part->partition) {
cur_part = list_entry(j, struct nvram_partition, partition);
if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
break;
}
part->header.length += cur_part->header.length;
part->header.checksum = nvram_checksum(&part->header);
part->index = cur_part->index;
list_del(&cur_part->partition);
kfree(cur_part);
j = &part->partition; /* fixup our loop */
}
/* Merge contiguous free partitions forwards */
list_for_each(j, &part->partition) {
cur_part = list_entry(j, struct nvram_partition, partition);
if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) {
break;
}
part->header.length += cur_part->header.length;
part->header.checksum = nvram_checksum(&part->header);
list_del(&cur_part->partition);
kfree(cur_part);
j = &part->partition; /* fixup our loop */
}
rc = nvram_write_header(part);
if (rc <= 0) {
printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc);
return rc;
}
}
return 0;
}
/* nvram_create_os_partition
*
* Create a OS linux partition to buffer error logs.
* Will create a partition starting at the first free
* space found if space has enough room.
*/
static int nvram_create_os_partition(void)
{
struct list_head * p;
struct nvram_partition *part = NULL;
struct nvram_partition *new_part = NULL;
struct nvram_partition *free_part = NULL;
int seq_init[2] = { 0, 0 };
loff_t tmp_index;
long size = 0;
int rc;
/* Find a free partition that will give us the maximum needed size
If can't find one that will give us the minimum size needed */
list_for_each(p, &nvram_part->partition) {
part = list_entry(p, struct nvram_partition, partition);
if (part->header.signature != NVRAM_SIG_FREE)
continue;
if (part->header.length >= NVRAM_MAX_REQ) {
size = NVRAM_MAX_REQ;
free_part = part;
break;
}
if (!size && part->header.length >= NVRAM_MIN_REQ) {
size = NVRAM_MIN_REQ;
free_part = part;
}
}
if (!size)
return -ENOSPC;
/* Create our OS partition */
new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
if (!new_part) {
printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n");
return -ENOMEM;
}
new_part->index = free_part->index;
new_part->header.signature = NVRAM_SIG_OS;
new_part->header.length = size;
strcpy(new_part->header.name, "ppc64,linux");
new_part->header.checksum = nvram_checksum(&new_part->header);
rc = nvram_write_header(new_part);
if (rc <= 0) {
printk(KERN_ERR "nvram_create_os_partition: nvram_write_header \
failed (%d)\n", rc);
return rc;
}
/* make sure and initialize to zero the sequence number and the error
type logged */
tmp_index = new_part->index + NVRAM_HEADER_LEN;
rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index);
if (rc <= 0) {
printk(KERN_ERR "nvram_create_os_partition: nvram_write "
"failed (%d)\n", rc);
return rc;
}
nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN;
nvram_error_log_size = ((part->header.length - 1) *
NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
list_add_tail(&new_part->partition, &free_part->partition);
if (free_part->header.length <= size) {
list_del(&free_part->partition);
kfree(free_part);
return 0;
}
/* Adjust the partition we stole the space from */
free_part->index += size * NVRAM_BLOCK_LEN;
free_part->header.length -= size;
free_part->header.checksum = nvram_checksum(&free_part->header);
rc = nvram_write_header(free_part);
if (rc <= 0) {
printk(KERN_ERR "nvram_create_os_partition: nvram_write_header "
"failed (%d)\n", rc);
return rc;
}
return 0;
}
/* nvram_setup_partition
*
* This will setup the partition we need for buffering the
* error logs and cleanup partitions if needed.
*
* The general strategy is the following:
* 1.) If there is ppc64,linux partition large enough then use it.
* 2.) If there is not a ppc64,linux partition large enough, search
* for a free partition that is large enough.
* 3.) If there is not a free partition large enough remove
* _all_ OS partitions and consolidate the space.
* 4.) Will first try getting a chunk that will satisfy the maximum
* error log size (NVRAM_MAX_REQ).
* 5.) If the max chunk cannot be allocated then try finding a chunk
* that will satisfy the minum needed (NVRAM_MIN_REQ).
*/
static int nvram_setup_partition(void)
{
struct list_head * p;
struct nvram_partition * part;
int rc;
/* For now, we don't do any of this on pmac, until I
* have figured out if it's worth killing some unused stuffs
* in our nvram, as Apple defined partitions use pretty much
* all of the space
*/
if (systemcfg->platform == PLATFORM_POWERMAC)
return -ENOSPC;
/* see if we have an OS partition that meets our needs.
will try getting the max we need. If not we'll delete
partitions and try again. */
list_for_each(p, &nvram_part->partition) {
part = list_entry(p, struct nvram_partition, partition);
if (part->header.signature != NVRAM_SIG_OS)
continue;
if (strcmp(part->header.name, "ppc64,linux"))
continue;
if (part->header.length >= NVRAM_MIN_REQ) {
/* found our partition */
nvram_error_log_index = part->index + NVRAM_HEADER_LEN;
nvram_error_log_size = ((part->header.length - 1) *
NVRAM_BLOCK_LEN) - sizeof(struct err_log_info);
return 0;
}
}
/* try creating a partition with the free space we have */
rc = nvram_create_os_partition();
if (!rc) {
return 0;
}
/* need to free up some space */
rc = nvram_remove_os_partition();
if (rc) {
return rc;
}
/* create a partition in this new space */
rc = nvram_create_os_partition();
if (rc) {
printk(KERN_ERR "nvram_create_os_partition: Could not find a "
"NVRAM partition large enough\n");
return rc;
}
return 0;
}
static int nvram_scan_partitions(void)
{
loff_t cur_index = 0;
struct nvram_header phead;
struct nvram_partition * tmp_part;
unsigned char c_sum;
char * header;
int total_size;
int err;
if (ppc_md.nvram_size == NULL)
return -ENODEV;
total_size = ppc_md.nvram_size();
header = (char *) kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
if (!header) {
printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
return -ENOMEM;
}
while (cur_index < total_size) {
err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
if (err != NVRAM_HEADER_LEN) {
printk(KERN_ERR "nvram_scan_partitions: Error parsing "
"nvram partitions\n");
goto out;
}
cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
memcpy(&phead, header, NVRAM_HEADER_LEN);
err = 0;
c_sum = nvram_checksum(&phead);
if (c_sum != phead.checksum) {
printk(KERN_WARNING "WARNING: nvram partition checksum"
" was %02x, should be %02x!\n",
phead.checksum, c_sum);
printk(KERN_WARNING "Terminating nvram partition scan\n");
goto out;
}
if (!phead.length) {
printk(KERN_WARNING "WARNING: nvram corruption "
"detected: 0-length partition\n");
goto out;
}
tmp_part = (struct nvram_partition *)
kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
err = -ENOMEM;
if (!tmp_part) {
printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
goto out;
}
memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
tmp_part->index = cur_index;
list_add_tail(&tmp_part->partition, &nvram_part->partition);
cur_index += phead.length * NVRAM_BLOCK_LEN;
}
err = 0;
out:
kfree(header);
return err;
}
static int __init nvram_init(void)
{
int error;
int rc;
if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
return -ENODEV;
rc = misc_register(&nvram_dev);
if (rc != 0) {
printk(KERN_ERR "nvram_init: failed to register device\n");
return rc;
}
/* initialize our anchor for the nvram partition list */
nvram_part = (struct nvram_partition *) kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
if (!nvram_part) {
printk(KERN_ERR "nvram_init: Failed kmalloc\n");
return -ENOMEM;
}
INIT_LIST_HEAD(&nvram_part->partition);
/* Get all the NVRAM partitions */
error = nvram_scan_partitions();
if (error) {
printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n");
return error;
}
if(nvram_setup_partition())
printk(KERN_WARNING "nvram_init: Could not find nvram partition"
" for nvram buffered error logging.\n");
#ifdef DEBUG_NVRAM
nvram_print_partitions("NVRAM Partitions");
#endif
return rc;
}
void __exit nvram_cleanup(void)
{
misc_deregister( &nvram_dev );
}
#ifdef CONFIG_PPC_PSERIES
/* nvram_write_error_log
*
* We need to buffer the error logs into nvram to ensure that we have
* the failure information to decode. If we have a severe error there
* is no way to guarantee that the OS or the machine is in a state to
* get back to user land and write the error to disk. For example if
* the SCSI device driver causes a Machine Check by writing to a bad
* IO address, there is no way of guaranteeing that the device driver
* is in any state that is would also be able to write the error data
* captured to disk, thus we buffer it in NVRAM for analysis on the
* next boot.
*
* In NVRAM the partition containing the error log buffer will looks like:
* Header (in bytes):
* +-----------+----------+--------+------------+------------------+
* | signature | checksum | length | name | data |
* |0 |1 |2 3|4 15|16 length-1|
* +-----------+----------+--------+------------+------------------+
*
* The 'data' section would look like (in bytes):
* +--------------+------------+-----------------------------------+
* | event_logged | sequence # | error log |
* |0 3|4 7|8 nvram_error_log_size-1|
* +--------------+------------+-----------------------------------+
*
* event_logged: 0 if event has not been logged to syslog, 1 if it has
* sequence #: The unique sequence # for each event. (until it wraps)
* error log: The error log from event_scan
*/
int nvram_write_error_log(char * buff, int length, unsigned int err_type)
{
int rc;
loff_t tmp_index;
struct err_log_info info;
if (no_logging) {
return -EPERM;
}
if (nvram_error_log_index == -1) {
return -ESPIPE;
}
if (length > nvram_error_log_size) {
length = nvram_error_log_size;
}
info.error_type = err_type;
info.seq_num = error_log_cnt;
tmp_index = nvram_error_log_index;
rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
if (rc <= 0) {
printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
return rc;
}
rc = ppc_md.nvram_write(buff, length, &tmp_index);
if (rc <= 0) {
printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
return rc;
}
return 0;
}
/* nvram_read_error_log
*
* Reads nvram for error log for at most 'length'
*/
int nvram_read_error_log(char * buff, int length, unsigned int * err_type)
{
int rc;
loff_t tmp_index;
struct err_log_info info;
if (nvram_error_log_index == -1)
return -1;
if (length > nvram_error_log_size)
length = nvram_error_log_size;
tmp_index = nvram_error_log_index;
rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
if (rc <= 0) {
printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
return rc;
}
rc = ppc_md.nvram_read(buff, length, &tmp_index);
if (rc <= 0) {
printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc);
return rc;
}
error_log_cnt = info.seq_num;
*err_type = info.error_type;
return 0;
}
/* This doesn't actually zero anything, but it sets the event_logged
* word to tell that this event is safely in syslog.
*/
int nvram_clear_error_log(void)
{
loff_t tmp_index;
int clear_word = ERR_FLAG_ALREADY_LOGGED;
int rc;
tmp_index = nvram_error_log_index;
rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
if (rc <= 0) {
printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
return rc;
}
return 0;
}
#endif /* CONFIG_PPC_PSERIES */
module_init(nvram_init);
module_exit(nvram_cleanup);
MODULE_LICENSE("GPL");
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