/*======================================================================
- $Id: slram.c,v 1.33 2005/01/05 18:05:13 dwmw2 Exp $
+ $Id: slram.c,v 1.36 2005/11/07 11:14:25 gleixner Exp $
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
<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 contigous memory region. Therfore
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/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)
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 :)
+ /* 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.
*/
{
slram_priv_t *priv = mtd->priv;
+ if (from + len > mtd->size)
+ return -EINVAL;
+
*mtdbuf = priv->start + from;
*retlen = len;
return(0);
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;
{
slram_priv_t *priv = mtd->priv;
+ if (to + len > mtd->size)
+ return -EINVAL;
+
memcpy(priv->start + to, buf, len);
*retlen = len;
}
(*curmtd)->mtdinfo = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
(*curmtd)->next = NULL;
-
+
if ((*curmtd)->mtdinfo) {
memset((char *)(*curmtd)->mtdinfo, 0, sizeof(struct mtd_info));
(*curmtd)->mtdinfo->priv =
kmalloc(sizeof(slram_priv_t), GFP_KERNEL);
-
+
if (!(*curmtd)->mtdinfo->priv) {
kfree((*curmtd)->mtdinfo);
(*curmtd)->mtdinfo = NULL;
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");
(*curmtd)->mtdinfo->name = name;
(*curmtd)->mtdinfo->size = length;
(*curmtd)->mtdinfo->flags = MTD_CLEAR_BITS | MTD_SET_BITS |
- MTD_WRITEB_WRITEABLE | MTD_VOLATILE;
+ MTD_WRITEB_WRITEABLE | MTD_VOLATILE | MTD_CAP_RAM;
(*curmtd)->mtdinfo->erase = slram_erase;
(*curmtd)->mtdinfo->point = slram_point;
(*curmtd)->mtdinfo->unpoint = slram_unpoint;
(*curmtd)->mtdinfo->write = slram_write;
(*curmtd)->mtdinfo->owner = THIS_MODULE;
(*curmtd)->mtdinfo->type = MTD_RAM;
- (*curmtd)->mtdinfo->erasesize = 0x0;
+ (*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;
if (add_mtd_device((*curmtd)->mtdinfo)) {
E("slram: Failed to register new device\n");
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);
+ return(0);
}
static void unregister_devices(void)
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;
}
T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n",
devname, devstart, devlength);
- if ((devstart < 0) || (devlength < 0)) {
+ if ((devstart < 0) || (devlength < 0) || (devlength % SLRAM_BLK_SZ != 0)) {
E("slram: Illegal start / length parameter.\n");
return(-EINVAL);
}
-
+
if ((devstart = register_device(devname, devstart, devlength))){
unregister_devices();
return((int)devstart);
}
#else
int count;
-
+
for (count = 0; (map[count]) && (count < SLRAM_MAX_DEVICES_PARAMS);
count++) {
}
if (parse_cmdline(devname, map[i * 3 + 1], map[i * 3 + 2])!=0) {
return(-EINVAL);
}
-
+
}
#endif /* !MODULE */
-
+
return(0);
}