/**
* $Id: phram.c,v 1.14 2005/03/07 21:43:38 joern Exp $
*
* Copyright (c) ???? Jochen Schäuble <psionic@psionic.de>
* Copyright (c) 2003-2004 Jörn Engel <joern@wh.fh-wedel.de>
*
* Usage:
*
* one commend line parameter per device, each in the form:
* phram=<name>,<start>,<len>
* <name> may be up to 63 characters.
* <start> and <len> can be octal, decimal or hexadecimal. If followed
* by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
* gigabytes.
*
* Example:
* phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
*/
#include <asm/io.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#define ERROR(fmt, args...) printk(KERN_ERR "phram: " fmt , ## args)
struct phram_mtd_list {
struct mtd_info mtd;
struct list_head list;
};
static LIST_HEAD(phram_list);
static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
{
u_char *start = mtd->priv;
if (instr->addr + instr->len > mtd->size)
return -EINVAL;
memset(start + instr->addr, 0xff, instr->len);
/* This'll catch a few races. Free the thing before returning :)
* I don't feel at all ashamed. This kind of thing is possible anyway
* with flash, but unlikely.
*/
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return 0;
}
static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char **mtdbuf)
{
u_char *start = mtd->priv;
if (from + len > mtd->size)
return -EINVAL;
*mtdbuf = start + from;
*retlen = len;
return 0;
}
static void phram_unpoint(struct mtd_info *mtd, u_char *addr, loff_t from,
size_t len)
{
}
static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
u_char *start = mtd->priv;
if (from >= mtd->size)
return -EINVAL;
if (len > mtd->size - from)
len = mtd->size - from;
memcpy(buf, start + from, len);
*retlen = len;
return 0;
}
static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
u_char *start = mtd->priv;
if (to >= mtd->size)
return -EINVAL;
if (len > mtd->size - to)
len = mtd->size - to;
memcpy(start + to, buf, len);
*retlen = len;
return 0;
}
static void unregister_devices(void)
{
struct phram_mtd_list *this, *safe;
list_for_each_entry_safe(this, safe, &phram_list, list) {
del_mtd_device(&this->mtd);
iounmap(this->mtd.priv);
kfree(this);
}
}
static int register_device(char *name, unsigned long start, unsigned long len)
{
struct phram_mtd_list *new;
int ret = -ENOMEM;
new = kmalloc(sizeof(*new), GFP_KERNEL);
if (!new)
goto out0;
memset(new, 0, sizeof(*new));
ret = -EIO;
new->mtd.priv = ioremap(start, len);
if (!new->mtd.priv) {
ERROR("ioremap failed\n");
goto out1;
}
new->mtd.name = name;
new->mtd.size = len;
new->mtd.flags = MTD_CAP_RAM | MTD_ERASEABLE | MTD_VOLATILE;
new->mtd.erase = phram_erase;
new->mtd.point = phram_point;
new->mtd.unpoint = phram_unpoint;
new->mtd.read = phram_read;
new->mtd.write = phram_write;
new->mtd.owner = THIS_MODULE;
new->mtd.type = MTD_RAM;
new->mtd.erasesize = PAGE_SIZE;
ret = -EAGAIN;
if (add_mtd_device(&new->mtd)) {
ERROR("Failed to register new device\n");
goto out2;
}
list_add_tail(&new->list, &phram_list);
return 0;
out2:
iounmap(new->mtd.priv);
out1:
kfree(new);
out0:
return ret;
}
static int ustrtoul(const char *cp, char **endp, unsigned int base)
{
unsigned long result = simple_strtoul(cp, endp, base);
switch (**endp) {
case 'G':
result *= 1024;
case 'M':
result *= 1024;
case 'k':
result *= 1024;
/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
if ((*endp)[1] == 'i')
(*endp) += 2;
}
return result;
}
static int parse_num32(uint32_t *num32, const char *token)
{
char *endp;
unsigned long n;
n = ustrtoul(token, &endp, 0);
if (*endp)
return -EINVAL;
*num32 = n;
return 0;
}
static int parse_name(char **pname, const char *token)
{
size_t len;
char *name;
len = strlen(token) + 1;
if (len > 64)
return -ENOSPC;
name = kmalloc(len, GFP_KERNEL);
if (!name)
return -ENOMEM;
strcpy(name, token);
*pname = name;
return 0;
}
static inline void kill_final_newline(char *str)
{
char *newline = strrchr(str, '\n');
if (newline && !newline[1])
*newline = 0;
}
#define parse_err(fmt, args...) do { \
ERROR(fmt , ## args); \
return 0; \
} while (0)
static int phram_setup(const char *val, struct kernel_param *kp)
{
char buf[64+12+12], *str = buf;
char *token[3];
char *name;
uint32_t start;
uint32_t len;
int i, ret;
if (strnlen(val, sizeof(buf)) >= sizeof(buf))
parse_err("parameter too long\n");
strcpy(str, val);
kill_final_newline(str);
for (i=0; i<3; i++)
token[i] = strsep(&str, ",");
if (str)
parse_err("too many arguments\n");
if (!token[2])
parse_err("not enough arguments\n");
ret = parse_name(&name, token[0]);
if (ret == -ENOMEM)
parse_err("out of memory\n");
if (ret == -ENOSPC)
parse_err("name too long\n");
if (ret)
return 0;
ret = parse_num32(&start, token[1]);
if (ret)
parse_err("illegal start address\n");
ret = parse_num32(&len, token[2]);
if (ret)
parse_err("illegal device length\n");
register_device(name, start, len);
return 0;
}
module_param_call(phram, phram_setup, NULL, NULL, 000);
MODULE_PARM_DESC(phram,"Memory region to map. \"map=<name>,<start>,<length>\"");
static int __init init_phram(void)
{
return 0;
}
static void __exit cleanup_phram(void)
{
unregister_devices();
}
module_init(init_phram);
module_exit(cleanup_phram);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jörn Engel <joern@wh.fh-wedel.de>");
MODULE_DESCRIPTION("MTD driver for physical RAM");
