forked from Minki/linux
5e4e6e3fdf
The 'mtd_unpoint()' API function should be able to return an error code because it may fail if you specify incorrect offset. This patch changes this MTD API function and amends all the drivers correspondingly. Also return '-EOPNOTSUPP' from 'mtd_unpoint()' when the '->unpoint()' method is undefined. We do not really need this currently, but this just makes sense to be consistent with 'mtd_point()'. Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
377 lines
9.1 KiB
C
377 lines
9.1 KiB
C
/*======================================================================
|
|
|
|
This driver provides a method to access memory not used by the kernel
|
|
itself (i.e. if the kernel commandline mem=xxx is used). To actually
|
|
use slram at least mtdblock or mtdchar is required (for block or
|
|
character device access).
|
|
|
|
Usage:
|
|
|
|
if compiled as loadable module:
|
|
modprobe slram map=<name>,<start>,<end/offset>
|
|
if statically linked into the kernel use the following kernel cmd.line
|
|
slram=<name>,<start>,<end/offset>
|
|
|
|
<name>: name of the device that will be listed in /proc/mtd
|
|
<start>: start of the memory region, decimal or hex (0xabcdef)
|
|
<end/offset>: end of the memory region. It's possible to use +0x1234
|
|
to specify the offset instead of the absolute address
|
|
|
|
NOTE:
|
|
With slram it's only possible to map a contiguous memory region. Therefore
|
|
if there's a device mapped somewhere in the region specified slram will
|
|
fail to load (see kernel log if modprobe fails).
|
|
|
|
-
|
|
|
|
Jochen Schaeuble <psionic@psionic.de>
|
|
|
|
======================================================================*/
|
|
|
|
|
|
#include <linux/module.h>
|
|
#include <asm/uaccess.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/major.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ioctl.h>
|
|
#include <linux/init.h>
|
|
#include <asm/io.h>
|
|
#include <asm/system.h>
|
|
|
|
#include <linux/mtd/mtd.h>
|
|
|
|
#define SLRAM_MAX_DEVICES_PARAMS 6 /* 3 parameters / device */
|
|
#define SLRAM_BLK_SZ 0x4000
|
|
|
|
#define T(fmt, args...) printk(KERN_DEBUG fmt, ## args)
|
|
#define E(fmt, args...) printk(KERN_NOTICE fmt, ## args)
|
|
|
|
typedef struct slram_priv {
|
|
u_char *start;
|
|
u_char *end;
|
|
} slram_priv_t;
|
|
|
|
typedef struct slram_mtd_list {
|
|
struct mtd_info *mtdinfo;
|
|
struct slram_mtd_list *next;
|
|
} slram_mtd_list_t;
|
|
|
|
#ifdef MODULE
|
|
static char *map[SLRAM_MAX_DEVICES_PARAMS];
|
|
|
|
module_param_array(map, charp, NULL, 0);
|
|
MODULE_PARM_DESC(map, "List of memory regions to map. \"map=<name>, <start>, <length / end>\"");
|
|
#else
|
|
static char *map;
|
|
#endif
|
|
|
|
static slram_mtd_list_t *slram_mtdlist = NULL;
|
|
|
|
static int slram_erase(struct mtd_info *, struct erase_info *);
|
|
static int slram_point(struct mtd_info *, loff_t, size_t, size_t *, void **,
|
|
resource_size_t *);
|
|
static int slram_unpoint(struct mtd_info *, loff_t, size_t);
|
|
static int slram_read(struct mtd_info *, loff_t, size_t, size_t *, u_char *);
|
|
static int slram_write(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
|
|
|
|
static int slram_erase(struct mtd_info *mtd, struct erase_info *instr)
|
|
{
|
|
slram_priv_t *priv = mtd->priv;
|
|
|
|
if (instr->addr + instr->len > mtd->size) {
|
|
return(-EINVAL);
|
|
}
|
|
|
|
memset(priv->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 slram_point(struct mtd_info *mtd, loff_t from, size_t len,
|
|
size_t *retlen, void **virt, resource_size_t *phys)
|
|
{
|
|
slram_priv_t *priv = mtd->priv;
|
|
|
|
/* can we return a physical address with this driver? */
|
|
if (phys)
|
|
return -EINVAL;
|
|
|
|
if (from + len > mtd->size)
|
|
return -EINVAL;
|
|
|
|
*virt = priv->start + from;
|
|
*retlen = len;
|
|
return(0);
|
|
}
|
|
|
|
static int slram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int slram_read(struct mtd_info *mtd, loff_t from, size_t len,
|
|
size_t *retlen, u_char *buf)
|
|
{
|
|
slram_priv_t *priv = mtd->priv;
|
|
|
|
if (from > mtd->size)
|
|
return -EINVAL;
|
|
|
|
if (from + len > mtd->size)
|
|
len = mtd->size - from;
|
|
|
|
memcpy(buf, priv->start + from, len);
|
|
|
|
*retlen = len;
|
|
return(0);
|
|
}
|
|
|
|
static int slram_write(struct mtd_info *mtd, loff_t to, size_t len,
|
|
size_t *retlen, const u_char *buf)
|
|
{
|
|
slram_priv_t *priv = mtd->priv;
|
|
|
|
if (to + len > mtd->size)
|
|
return -EINVAL;
|
|
|
|
memcpy(priv->start + to, buf, len);
|
|
|
|
*retlen = len;
|
|
return(0);
|
|
}
|
|
|
|
/*====================================================================*/
|
|
|
|
static int register_device(char *name, unsigned long start, unsigned long length)
|
|
{
|
|
slram_mtd_list_t **curmtd;
|
|
|
|
curmtd = &slram_mtdlist;
|
|
while (*curmtd) {
|
|
curmtd = &(*curmtd)->next;
|
|
}
|
|
|
|
*curmtd = kmalloc(sizeof(slram_mtd_list_t), GFP_KERNEL);
|
|
if (!(*curmtd)) {
|
|
E("slram: Cannot allocate new MTD device.\n");
|
|
return(-ENOMEM);
|
|
}
|
|
(*curmtd)->mtdinfo = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
|
|
(*curmtd)->next = NULL;
|
|
|
|
if ((*curmtd)->mtdinfo) {
|
|
(*curmtd)->mtdinfo->priv =
|
|
kzalloc(sizeof(slram_priv_t), GFP_KERNEL);
|
|
|
|
if (!(*curmtd)->mtdinfo->priv) {
|
|
kfree((*curmtd)->mtdinfo);
|
|
(*curmtd)->mtdinfo = NULL;
|
|
}
|
|
}
|
|
|
|
if (!(*curmtd)->mtdinfo) {
|
|
E("slram: Cannot allocate new MTD device.\n");
|
|
return(-ENOMEM);
|
|
}
|
|
|
|
if (!(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start =
|
|
ioremap(start, length))) {
|
|
E("slram: ioremap failed\n");
|
|
return -EIO;
|
|
}
|
|
((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end =
|
|
((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start + length;
|
|
|
|
|
|
(*curmtd)->mtdinfo->name = name;
|
|
(*curmtd)->mtdinfo->size = length;
|
|
(*curmtd)->mtdinfo->flags = MTD_CAP_RAM;
|
|
(*curmtd)->mtdinfo->_erase = slram_erase;
|
|
(*curmtd)->mtdinfo->_point = slram_point;
|
|
(*curmtd)->mtdinfo->_unpoint = slram_unpoint;
|
|
(*curmtd)->mtdinfo->_read = slram_read;
|
|
(*curmtd)->mtdinfo->_write = slram_write;
|
|
(*curmtd)->mtdinfo->owner = THIS_MODULE;
|
|
(*curmtd)->mtdinfo->type = MTD_RAM;
|
|
(*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;
|
|
(*curmtd)->mtdinfo->writesize = 1;
|
|
|
|
if (mtd_device_register((*curmtd)->mtdinfo, NULL, 0)) {
|
|
E("slram: Failed to register new device\n");
|
|
iounmap(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start);
|
|
kfree((*curmtd)->mtdinfo->priv);
|
|
kfree((*curmtd)->mtdinfo);
|
|
return(-EAGAIN);
|
|
}
|
|
T("slram: Registered device %s from %luKiB to %luKiB\n", name,
|
|
(start / 1024), ((start + length) / 1024));
|
|
T("slram: Mapped from 0x%p to 0x%p\n",
|
|
((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start,
|
|
((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end);
|
|
return(0);
|
|
}
|
|
|
|
static void unregister_devices(void)
|
|
{
|
|
slram_mtd_list_t *nextitem;
|
|
|
|
while (slram_mtdlist) {
|
|
nextitem = slram_mtdlist->next;
|
|
mtd_device_unregister(slram_mtdlist->mtdinfo);
|
|
iounmap(((slram_priv_t *)slram_mtdlist->mtdinfo->priv)->start);
|
|
kfree(slram_mtdlist->mtdinfo->priv);
|
|
kfree(slram_mtdlist->mtdinfo);
|
|
kfree(slram_mtdlist);
|
|
slram_mtdlist = nextitem;
|
|
}
|
|
}
|
|
|
|
static unsigned long handle_unit(unsigned long value, char *unit)
|
|
{
|
|
if ((*unit == 'M') || (*unit == 'm')) {
|
|
return(value * 1024 * 1024);
|
|
} else if ((*unit == 'K') || (*unit == 'k')) {
|
|
return(value * 1024);
|
|
}
|
|
return(value);
|
|
}
|
|
|
|
static int parse_cmdline(char *devname, char *szstart, char *szlength)
|
|
{
|
|
char *buffer;
|
|
unsigned long devstart;
|
|
unsigned long devlength;
|
|
|
|
if ((!devname) || (!szstart) || (!szlength)) {
|
|
unregister_devices();
|
|
return(-EINVAL);
|
|
}
|
|
|
|
devstart = simple_strtoul(szstart, &buffer, 0);
|
|
devstart = handle_unit(devstart, buffer);
|
|
|
|
if (*(szlength) != '+') {
|
|
devlength = simple_strtoul(szlength, &buffer, 0);
|
|
devlength = handle_unit(devlength, buffer) - devstart;
|
|
if (devlength < devstart)
|
|
goto err_out;
|
|
|
|
devlength -= devstart;
|
|
} else {
|
|
devlength = simple_strtoul(szlength + 1, &buffer, 0);
|
|
devlength = handle_unit(devlength, buffer);
|
|
}
|
|
T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n",
|
|
devname, devstart, devlength);
|
|
if (devlength % SLRAM_BLK_SZ != 0)
|
|
goto err_out;
|
|
|
|
if ((devstart = register_device(devname, devstart, devlength))){
|
|
unregister_devices();
|
|
return((int)devstart);
|
|
}
|
|
return(0);
|
|
|
|
err_out:
|
|
E("slram: Illegal length parameter.\n");
|
|
return(-EINVAL);
|
|
}
|
|
|
|
#ifndef MODULE
|
|
|
|
static int __init mtd_slram_setup(char *str)
|
|
{
|
|
map = str;
|
|
return(1);
|
|
}
|
|
|
|
__setup("slram=", mtd_slram_setup);
|
|
|
|
#endif
|
|
|
|
static int __init init_slram(void)
|
|
{
|
|
char *devname;
|
|
int i;
|
|
|
|
#ifndef MODULE
|
|
char *devstart;
|
|
char *devlength;
|
|
|
|
i = 0;
|
|
|
|
if (!map) {
|
|
E("slram: not enough parameters.\n");
|
|
return(-EINVAL);
|
|
}
|
|
while (map) {
|
|
devname = devstart = devlength = NULL;
|
|
|
|
if (!(devname = strsep(&map, ","))) {
|
|
E("slram: No devicename specified.\n");
|
|
break;
|
|
}
|
|
T("slram: devname = %s\n", devname);
|
|
if ((!map) || (!(devstart = strsep(&map, ",")))) {
|
|
E("slram: No devicestart specified.\n");
|
|
}
|
|
T("slram: devstart = %s\n", devstart);
|
|
if ((!map) || (!(devlength = strsep(&map, ",")))) {
|
|
E("slram: No devicelength / -end specified.\n");
|
|
}
|
|
T("slram: devlength = %s\n", devlength);
|
|
if (parse_cmdline(devname, devstart, devlength) != 0) {
|
|
return(-EINVAL);
|
|
}
|
|
}
|
|
#else
|
|
int count;
|
|
|
|
for (count = 0; count < SLRAM_MAX_DEVICES_PARAMS && map[count];
|
|
count++) {
|
|
}
|
|
|
|
if ((count % 3 != 0) || (count == 0)) {
|
|
E("slram: not enough parameters.\n");
|
|
return(-EINVAL);
|
|
}
|
|
for (i = 0; i < (count / 3); i++) {
|
|
devname = map[i * 3];
|
|
|
|
if (parse_cmdline(devname, map[i * 3 + 1], map[i * 3 + 2])!=0) {
|
|
return(-EINVAL);
|
|
}
|
|
|
|
}
|
|
#endif /* !MODULE */
|
|
|
|
return(0);
|
|
}
|
|
|
|
static void __exit cleanup_slram(void)
|
|
{
|
|
unregister_devices();
|
|
}
|
|
|
|
module_init(init_slram);
|
|
module_exit(cleanup_slram);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Jochen Schaeuble <psionic@psionic.de>");
|
|
MODULE_DESCRIPTION("MTD driver for uncached system RAM");
|