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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/arch/powerpc/kernel/nvram_64.c

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31 KiB
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/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 <linux/kmsg_dump.h>
#include <linux/pagemap.h>
#include <linux/pstore.h>
#include <linux/zlib.h>
#include <linux/uaccess.h>
#include <asm/nvram.h>
#include <asm/rtas.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#undef DEBUG_NVRAM
#define NVRAM_HEADER_LEN sizeof(struct nvram_header)
#define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN
/* If change this size, then change the size of NVNAME_LEN */
struct nvram_header {
unsigned char signature;
unsigned char checksum;
unsigned short length;
/* Terminating null required only for names < 12 chars. */
char name[12];
};
struct nvram_partition {
struct list_head partition;
struct nvram_header header;
unsigned int index;
};
static LIST_HEAD(nvram_partitions);
#ifdef CONFIG_PPC_PSERIES
struct nvram_os_partition rtas_log_partition = {
.name = "ibm,rtas-log",
.req_size = 2079,
.min_size = 1055,
.index = -1,
.os_partition = true
};
#endif
struct nvram_os_partition oops_log_partition = {
.name = "lnx,oops-log",
.req_size = 4000,
.min_size = 2000,
.index = -1,
.os_partition = true
};
static const char *nvram_os_partitions[] = {
#ifdef CONFIG_PPC_PSERIES
"ibm,rtas-log",
#endif
"lnx,oops-log",
NULL
};
static void oops_to_nvram(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason);
static struct kmsg_dumper nvram_kmsg_dumper = {
.dump = oops_to_nvram
};
/*
* For capturing and compressing an oops or panic report...
* big_oops_buf[] holds the uncompressed text we're capturing.
*
* oops_buf[] holds the compressed text, preceded by a oops header.
* oops header has u16 holding the version of oops header (to differentiate
* between old and new format header) followed by u16 holding the length of
* the compressed* text (*Or uncompressed, if compression fails.) and u64
* holding the timestamp. oops_buf[] gets written to NVRAM.
*
* oops_log_info points to the header. oops_data points to the compressed text.
*
* +- oops_buf
* | +- oops_data
* v v
* +-----------+-----------+-----------+------------------------+
* | version | length | timestamp | text |
* | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes) |
* +-----------+-----------+-----------+------------------------+
* ^
* +- oops_log_info
*
* We preallocate these buffers during init to avoid kmalloc during oops/panic.
*/
static size_t big_oops_buf_sz;
static char *big_oops_buf, *oops_buf;
static char *oops_data;
static size_t oops_data_sz;
/* Compression parameters */
#define COMPR_LEVEL 6
#define WINDOW_BITS 12
#define MEM_LEVEL 4
static struct z_stream_s stream;
#ifdef CONFIG_PSTORE
#ifdef CONFIG_PPC_POWERNV
static struct nvram_os_partition skiboot_partition = {
.name = "ibm,skiboot",
.index = -1,
.os_partition = false
};
#endif
#ifdef CONFIG_PPC_PSERIES
static struct nvram_os_partition of_config_partition = {
.name = "of-config",
.index = -1,
.os_partition = false
};
#endif
static struct nvram_os_partition common_partition = {
.name = "common",
.index = -1,
.os_partition = false
};
static enum pstore_type_id nvram_type_ids[] = {
PSTORE_TYPE_DMESG,
PSTORE_TYPE_PPC_COMMON,
-1,
-1,
-1
};
static int read_type;
#endif
/* nvram_write_os_partition
*
* 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 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_os_partition(struct nvram_os_partition *part,
char *buff, int length,
unsigned int err_type,
unsigned int error_log_cnt)
{
int rc;
loff_t tmp_index;
struct err_log_info info;
if (part->index == -1)
return -ESPIPE;
if (length > part->size)
length = part->size;
info.error_type = cpu_to_be32(err_type);
info.seq_num = cpu_to_be32(error_log_cnt);
tmp_index = part->index;
rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info),
&tmp_index);
if (rc <= 0) {
pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
return rc;
}
rc = ppc_md.nvram_write(buff, length, &tmp_index);
if (rc <= 0) {
pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
return rc;
}
return 0;
}
/* nvram_read_partition
*
* Reads nvram partition for at most 'length'
*/
int nvram_read_partition(struct nvram_os_partition *part, char *buff,
int length, unsigned int *err_type,
unsigned int *error_log_cnt)
{
int rc;
loff_t tmp_index;
struct err_log_info info;
if (part->index == -1)
return -1;
if (length > part->size)
length = part->size;
tmp_index = part->index;
if (part->os_partition) {
rc = ppc_md.nvram_read((char *)&info,
sizeof(struct err_log_info),
&tmp_index);
if (rc <= 0) {
pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
return rc;
}
}
rc = ppc_md.nvram_read(buff, length, &tmp_index);
if (rc <= 0) {
pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
return rc;
}
if (part->os_partition) {
*error_log_cnt = be32_to_cpu(info.seq_num);
*err_type = be32_to_cpu(info.error_type);
}
return 0;
}
/* nvram_init_os_partition
*
* This sets up a partition with an "OS" signature.
*
* The general strategy is the following:
* 1.) If a partition with the indicated name already exists...
* - If it's large enough, use it.
* - Otherwise, recycle it and keep going.
* 2.) Search for a free partition that is large enough.
* 3.) If there's not a free partition large enough, recycle any obsolete
* OS partitions and try again.
* 4.) Will first try getting a chunk that will satisfy the requested size.
* 5.) If a chunk of the requested size cannot be allocated, then try finding
* a chunk that will satisfy the minum needed.
*
* Returns 0 on success, else -1.
*/
int __init nvram_init_os_partition(struct nvram_os_partition *part)
{
loff_t p;
int size;
/* Look for ours */
p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
/* Found one but too small, remove it */
if (p && size < part->min_size) {
pr_info("nvram: Found too small %s partition,"
" removing it...\n", part->name);
nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
p = 0;
}
/* Create one if we didn't find */
if (!p) {
p = nvram_create_partition(part->name, NVRAM_SIG_OS,
part->req_size, part->min_size);
if (p == -ENOSPC) {
pr_info("nvram: No room to create %s partition, "
"deleting any obsolete OS partitions...\n",
part->name);
nvram_remove_partition(NULL, NVRAM_SIG_OS,
nvram_os_partitions);
p = nvram_create_partition(part->name, NVRAM_SIG_OS,
part->req_size, part->min_size);
}
}
if (p <= 0) {
pr_err("nvram: Failed to find or create %s"
" partition, err %d\n", part->name, (int)p);
return -1;
}
part->index = p;
part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
return 0;
}
/* Derived from logfs_compress() */
static int nvram_compress(const void *in, void *out, size_t inlen,
size_t outlen)
{
int err, ret;
ret = -EIO;
err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
MEM_LEVEL, Z_DEFAULT_STRATEGY);
if (err != Z_OK)
goto error;
stream.next_in = in;
stream.avail_in = inlen;
stream.total_in = 0;
stream.next_out = out;
stream.avail_out = outlen;
stream.total_out = 0;
err = zlib_deflate(&stream, Z_FINISH);
if (err != Z_STREAM_END)
goto error;
err = zlib_deflateEnd(&stream);
if (err != Z_OK)
goto error;
if (stream.total_out >= stream.total_in)
goto error;
ret = stream.total_out;
error:
return ret;
}
/* Compress the text from big_oops_buf into oops_buf. */
static int zip_oops(size_t text_len)
{
struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
oops_data_sz);
if (zipped_len < 0) {
pr_err("nvram: compression failed; returned %d\n", zipped_len);
pr_err("nvram: logging uncompressed oops/panic report\n");
return -1;
}
oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
oops_hdr->report_length = cpu_to_be16(zipped_len);
oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
return 0;
}
#ifdef CONFIG_PSTORE
static int nvram_pstore_open(struct pstore_info *psi)
{
/* Reset the iterator to start reading partitions again */
read_type = -1;
return 0;
}
/**
* nvram_pstore_write - pstore write callback for nvram
* @record: pstore record to write, with @id to be set
*
* Called by pstore_dump() when an oops or panic report is logged in the
* printk buffer.
* Returns 0 on successful write.
*/
static int nvram_pstore_write(struct pstore_record *record)
{
int rc;
unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
/* part 1 has the recent messages from printk buffer */
if (record->part > 1 || (record->type != PSTORE_TYPE_DMESG))
return -1;
if (clobbering_unread_rtas_event())
return -1;
oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
oops_hdr->report_length = cpu_to_be16(record->size);
oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
if (record->compressed)
err_type = ERR_TYPE_KERNEL_PANIC_GZ;
rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
(int) (sizeof(*oops_hdr) + record->size), err_type,
record->count);
if (rc != 0)
return rc;
record->id = record->part;
return 0;
}
/*
* Reads the oops/panic report, rtas, of-config and common partition.
* Returns the length of the data we read from each partition.
* Returns 0 if we've been called before.
*/
static ssize_t nvram_pstore_read(struct pstore_record *record)
{
struct oops_log_info *oops_hdr;
unsigned int err_type, id_no, size = 0;
struct nvram_os_partition *part = NULL;
char *buff = NULL;
int sig = 0;
loff_t p;
read_type++;
switch (nvram_type_ids[read_type]) {
case PSTORE_TYPE_DMESG:
part = &oops_log_partition;
record->type = PSTORE_TYPE_DMESG;
break;
case PSTORE_TYPE_PPC_COMMON:
sig = NVRAM_SIG_SYS;
part = &common_partition;
record->type = PSTORE_TYPE_PPC_COMMON;
record->id = PSTORE_TYPE_PPC_COMMON;
record->time.tv_sec = 0;
record->time.tv_nsec = 0;
break;
#ifdef CONFIG_PPC_PSERIES
case PSTORE_TYPE_PPC_RTAS:
part = &rtas_log_partition;
record->type = PSTORE_TYPE_PPC_RTAS;
record->time.tv_sec = last_rtas_event;
record->time.tv_nsec = 0;
break;
case PSTORE_TYPE_PPC_OF:
sig = NVRAM_SIG_OF;
part = &of_config_partition;
record->type = PSTORE_TYPE_PPC_OF;
record->id = PSTORE_TYPE_PPC_OF;
record->time.tv_sec = 0;
record->time.tv_nsec = 0;
break;
#endif
#ifdef CONFIG_PPC_POWERNV
case PSTORE_TYPE_PPC_OPAL:
sig = NVRAM_SIG_FW;
part = &skiboot_partition;
record->type = PSTORE_TYPE_PPC_OPAL;
record->id = PSTORE_TYPE_PPC_OPAL;
record->time.tv_sec = 0;
record->time.tv_nsec = 0;
break;
#endif
default:
return 0;
}
if (!part->os_partition) {
p = nvram_find_partition(part->name, sig, &size);
if (p <= 0) {
pr_err("nvram: Failed to find partition %s, "
"err %d\n", part->name, (int)p);
return 0;
}
part->index = p;
part->size = size;
}
buff = kmalloc(part->size, GFP_KERNEL);
if (!buff)
return -ENOMEM;
if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
kfree(buff);
return 0;
}
record->count = 0;
if (part->os_partition)
record->id = id_no;
if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
size_t length, hdr_size;
oops_hdr = (struct oops_log_info *)buff;
if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
/* Old format oops header had 2-byte record size */
hdr_size = sizeof(u16);
length = be16_to_cpu(oops_hdr->version);
record->time.tv_sec = 0;
record->time.tv_nsec = 0;
} else {
hdr_size = sizeof(*oops_hdr);
length = be16_to_cpu(oops_hdr->report_length);
record->time.tv_sec = be64_to_cpu(oops_hdr->timestamp);
record->time.tv_nsec = 0;
}
record->buf = kmemdup(buff + hdr_size, length, GFP_KERNEL);
kfree(buff);
if (record->buf == NULL)
return -ENOMEM;
record->ecc_notice_size = 0;
if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
record->compressed = true;
else
record->compressed = false;
return length;
}
record->buf = buff;
return part->size;
}
static struct pstore_info nvram_pstore_info = {
.owner = THIS_MODULE,
.name = "nvram",
.flags = PSTORE_FLAGS_DMESG,
.open = nvram_pstore_open,
.read = nvram_pstore_read,
.write = nvram_pstore_write,
};
static int nvram_pstore_init(void)
{
int rc = 0;
if (machine_is(pseries)) {
nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;
} else
nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL;
nvram_pstore_info.buf = oops_data;
nvram_pstore_info.bufsize = oops_data_sz;
spin_lock_init(&nvram_pstore_info.buf_lock);
rc = pstore_register(&nvram_pstore_info);
if (rc && (rc != -EPERM))
/* Print error only when pstore.backend == nvram */
pr_err("nvram: pstore_register() failed, returned %d. "
"Defaults to kmsg_dump\n", rc);
return rc;
}
#else
static int nvram_pstore_init(void)
{
return -1;
}
#endif
void __init nvram_init_oops_partition(int rtas_partition_exists)
{
int rc;
rc = nvram_init_os_partition(&oops_log_partition);
if (rc != 0) {
#ifdef CONFIG_PPC_PSERIES
if (!rtas_partition_exists) {
pr_err("nvram: Failed to initialize oops partition!");
return;
}
pr_notice("nvram: Using %s partition to log both"
" RTAS errors and oops/panic reports\n",
rtas_log_partition.name);
memcpy(&oops_log_partition, &rtas_log_partition,
sizeof(rtas_log_partition));
#else
pr_err("nvram: Failed to initialize oops partition!");
return;
#endif
}
oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
if (!oops_buf) {
pr_err("nvram: No memory for %s partition\n",
oops_log_partition.name);
return;
}
oops_data = oops_buf + sizeof(struct oops_log_info);
oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
rc = nvram_pstore_init();
if (!rc)
return;
/*
* Figure compression (preceded by elimination of each line's <n>
* severity prefix) will reduce the oops/panic report to at most
* 45% of its original size.
*/
big_oops_buf_sz = (oops_data_sz * 100) / 45;
big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
if (big_oops_buf) {
stream.workspace = kmalloc(zlib_deflate_workspacesize(
WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
if (!stream.workspace) {
pr_err("nvram: No memory for compression workspace; "
"skipping compression of %s partition data\n",
oops_log_partition.name);
kfree(big_oops_buf);
big_oops_buf = NULL;
}
} else {
pr_err("No memory for uncompressed %s data; "
"skipping compression\n", oops_log_partition.name);
stream.workspace = NULL;
}
rc = kmsg_dump_register(&nvram_kmsg_dumper);
if (rc != 0) {
pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
kfree(oops_buf);
kfree(big_oops_buf);
kfree(stream.workspace);
}
}
/*
* This is our kmsg_dump callback, called after an oops or panic report
* has been written to the printk buffer. We want to capture as much
* of the printk buffer as possible. First, capture as much as we can
* that we think will compress sufficiently to fit in the lnx,oops-log
* partition. If that's too much, go back and capture uncompressed text.
*/
static void oops_to_nvram(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason)
{
struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
static unsigned int oops_count = 0;
static bool panicking = false;
static DEFINE_SPINLOCK(lock);
unsigned long flags;
size_t text_len;
unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
int rc = -1;
switch (reason) {
case KMSG_DUMP_RESTART:
case KMSG_DUMP_HALT:
case KMSG_DUMP_POWEROFF:
/* These are almost always orderly shutdowns. */
return;
case KMSG_DUMP_OOPS:
break;
case KMSG_DUMP_PANIC:
panicking = true;
break;
case KMSG_DUMP_EMERG:
if (panicking)
/* Panic report already captured. */
return;
break;
default:
pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
__func__, (int) reason);
return;
}
if (clobbering_unread_rtas_event())
return;
if (!spin_trylock_irqsave(&lock, flags))
return;
if (big_oops_buf) {
kmsg_dump_get_buffer(dumper, false,
big_oops_buf, big_oops_buf_sz, &text_len);
rc = zip_oops(text_len);
}
if (rc != 0) {
kmsg_dump_rewind(dumper);
kmsg_dump_get_buffer(dumper, false,
oops_data, oops_data_sz, &text_len);
err_type = ERR_TYPE_KERNEL_PANIC;
oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
oops_hdr->report_length = cpu_to_be16(text_len);
oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
}
(void) nvram_write_os_partition(&oops_log_partition, oops_buf,
(int) (sizeof(*oops_hdr) + text_len), err_type,
++oops_count);
spin_unlock_irqrestore(&lock, flags);
}
static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
{
if (ppc_md.nvram_size == NULL)
return -ENODEV;
return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE,
ppc_md.nvram_size());
}
static ssize_t dev_nvram_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t ret;
char *tmp = NULL;
ssize_t size;
if (!ppc_md.nvram_size) {
ret = -ENODEV;
goto out;
}
size = ppc_md.nvram_size();
if (size < 0) {
ret = size;
goto out;
}
if (*ppos >= size) {
ret = 0;
goto out;
}
count = min_t(size_t, count, size - *ppos);
count = min(count, PAGE_SIZE);
tmp = kmalloc(count, GFP_KERNEL);
if (!tmp) {
ret = -ENOMEM;
goto out;
}
ret = ppc_md.nvram_read(tmp, count, ppos);
if (ret <= 0)
goto out;
if (copy_to_user(buf, tmp, ret))
ret = -EFAULT;
out:
kfree(tmp);
return ret;
}
static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t ret;
char *tmp = NULL;
ssize_t size;
ret = -ENODEV;
if (!ppc_md.nvram_size)
goto out;
ret = 0;
size = ppc_md.nvram_size();
if (*ppos >= size || size < 0)
goto out;
count = min_t(size_t, count, size - *ppos);
count = min(count, PAGE_SIZE);
tmp = memdup_user(buf, count);
if (IS_ERR(tmp)) {
ret = PTR_ERR(tmp);
goto out;
}
ret = ppc_md.nvram_write(tmp, count, ppos);
kfree(tmp);
out:
return ret;
}
static long dev_nvram_ioctl(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 (!machine_is(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 */
default:
return -EINVAL;
}
}
static const struct file_operations nvram_fops = {
.owner = THIS_MODULE,
.llseek = dev_nvram_llseek,
.read = dev_nvram_read,
.write = dev_nvram_write,
.unlocked_ioctl = dev_nvram_ioctl,
};
static struct miscdevice nvram_dev = {
NVRAM_MINOR,
"nvram",
&nvram_fops
};
#ifdef DEBUG_NVRAM
static void __init nvram_print_partitions(char * label)
{
struct nvram_partition * tmp_part;
printk(KERN_WARNING "--------%s---------\n", label);
printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
list_for_each_entry(tmp_part, &nvram_partitions, partition) {
printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12.12s\n",
tmp_part->index, tmp_part->header.signature,
tmp_part->header.checksum, tmp_part->header.length,
tmp_part->header.name);
}
}
#endif
static int __init nvram_write_header(struct nvram_partition * part)
{
loff_t tmp_index;
int rc;
struct nvram_header phead;
memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
phead.length = cpu_to_be16(phead.length);
tmp_index = part->index;
rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);
return rc;
}
static unsigned char __init 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;
}
/*
* Per the criteria passed via nvram_remove_partition(), should this
* partition be removed? 1=remove, 0=keep
*/
static int nvram_can_remove_partition(struct nvram_partition *part,
const char *name, int sig, const char *exceptions[])
{
if (part->header.signature != sig)
return 0;
if (name) {
if (strncmp(name, part->header.name, 12))
return 0;
} else if (exceptions) {
const char **except;
for (except = exceptions; *except; except++) {
if (!strncmp(*except, part->header.name, 12))
return 0;
}
}
return 1;
}
/**
* nvram_remove_partition - Remove one or more partitions in nvram
* @name: name of the partition to remove, or NULL for a
* signature only match
* @sig: signature of the partition(s) to remove
* @exceptions: When removing all partitions with a matching signature,
* leave these alone.
*/
int __init nvram_remove_partition(const char *name, int sig,
const char *exceptions[])
{
struct nvram_partition *part, *prev, *tmp;
int rc;
list_for_each_entry(part, &nvram_partitions, partition) {
if (!nvram_can_remove_partition(part, name, sig, exceptions))
continue;
/* Make partition a free partition */
part->header.signature = NVRAM_SIG_FREE;
memset(part->header.name, 'w', 12);
part->header.checksum = nvram_checksum(&part->header);
rc = nvram_write_header(part);
if (rc <= 0) {
printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
return rc;
}
}
/* Merge contiguous ones */
prev = NULL;
list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
if (part->header.signature != NVRAM_SIG_FREE) {
prev = NULL;
continue;
}
if (prev) {
prev->header.length += part->header.length;
prev->header.checksum = nvram_checksum(&prev->header);
rc = nvram_write_header(prev);
if (rc <= 0) {
printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
return rc;
}
list_del(&part->partition);
kfree(part);
} else
prev = part;
}
return 0;
}
/**
* nvram_create_partition - Create a partition in nvram
* @name: name of the partition to create
* @sig: signature of the partition to create
* @req_size: size of data to allocate in bytes
* @min_size: minimum acceptable size (0 means req_size)
*
* Returns a negative error code or a positive nvram index
* of the beginning of the data area of the newly created
* partition. If you provided a min_size smaller than req_size
* you need to query for the actual size yourself after the
* call using nvram_partition_get_size().
*/
loff_t __init nvram_create_partition(const char *name, int sig,
int req_size, int min_size)
{
struct nvram_partition *part;
struct nvram_partition *new_part;
struct nvram_partition *free_part = NULL;
static char nv_init_vals[16];
loff_t tmp_index;
long size = 0;
int rc;
/* Convert sizes from bytes to blocks */
req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
/* If no minimum size specified, make it the same as the
* requested size
*/
if (min_size == 0)
min_size = req_size;
if (min_size > req_size)
return -EINVAL;
/* Now add one block to each for the header */
req_size += 1;
min_size += 1;
/* 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_entry(part, &nvram_partitions, partition) {
if (part->header.signature != NVRAM_SIG_FREE)
continue;
if (part->header.length >= req_size) {
size = req_size;
free_part = part;
break;
}
if (part->header.length > size &&
part->header.length >= min_size) {
size = part->header.length;
free_part = part;
}
}
if (!size)
return -ENOSPC;
/* Create our OS partition */
new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
if (!new_part) {
pr_err("%s: kmalloc failed\n", __func__);
return -ENOMEM;
}
new_part->index = free_part->index;
new_part->header.signature = sig;
new_part->header.length = size;
strncpy(new_part->header.name, name, 12);
new_part->header.checksum = nvram_checksum(&new_part->header);
rc = nvram_write_header(new_part);
if (rc <= 0) {
pr_err("%s: nvram_write_header failed (%d)\n", __func__, rc);
kfree(new_part);
return rc;
}
list_add_tail(&new_part->partition, &free_part->partition);
/* Adjust or remove the partition we stole the space from */
if (free_part->header.length > size) {
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) {
pr_err("%s: nvram_write_header failed (%d)\n",
__func__, rc);
return rc;
}
} else {
list_del(&free_part->partition);
kfree(free_part);
}
/* Clear the new partition */
for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
tmp_index < ((size - 1) * NVRAM_BLOCK_LEN);
tmp_index += NVRAM_BLOCK_LEN) {
rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
if (rc <= 0) {
pr_err("%s: nvram_write failed (%d)\n",
__func__, rc);
return rc;
}
}
return new_part->index + NVRAM_HEADER_LEN;
}
/**
* nvram_get_partition_size - Get the data size of an nvram partition
* @data_index: This is the offset of the start of the data of
* the partition. The same value that is returned by
* nvram_create_partition().
*/
int nvram_get_partition_size(loff_t data_index)
{
struct nvram_partition *part;
list_for_each_entry(part, &nvram_partitions, partition) {
if (part->index + NVRAM_HEADER_LEN == data_index)
return (part->header.length - 1) * NVRAM_BLOCK_LEN;
}
return -1;
}
/**
* nvram_find_partition - Find an nvram partition by signature and name
* @name: Name of the partition or NULL for any name
* @sig: Signature to test against
* @out_size: if non-NULL, returns the size of the data part of the partition
*/
loff_t nvram_find_partition(const char *name, int sig, int *out_size)
{
struct nvram_partition *p;
list_for_each_entry(p, &nvram_partitions, partition) {
if (p->header.signature == sig &&
(!name || !strncmp(p->header.name, name, 12))) {
if (out_size)
*out_size = (p->header.length - 1) *
NVRAM_BLOCK_LEN;
return p->index + NVRAM_HEADER_LEN;
}
}
return 0;
}
int __init 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 || ppc_md.nvram_size() <= 0)
return -ENODEV;
total_size = ppc_md.nvram_size();
header = 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);
phead.length = be16_to_cpu(phead.length);
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 = 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_partitions);
cur_index += phead.length * NVRAM_BLOCK_LEN;
}
err = 0;
#ifdef DEBUG_NVRAM
nvram_print_partitions("NVRAM Partitions");
#endif
out:
kfree(header);
return err;
}
static int __init nvram_init(void)
{
int rc;
BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
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;
}
return rc;
}
device_initcall(nvram_init);
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