2005-04-16 16:20:36 -06:00
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/*======================================================================
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This driver provides a method to access memory not used by the kernel
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itself (i.e. if the kernel commandline mem=xxx is used). To actually
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use slram at least mtdblock or mtdchar is required (for block or
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character device access).
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Usage:
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if compiled as loadable module:
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modprobe slram map=<name>,<start>,<end/offset>
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if statically linked into the kernel use the following kernel cmd.line
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slram=<name>,<start>,<end/offset>
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<name>: name of the device that will be listed in /proc/mtd
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<start>: start of the memory region, decimal or hex (0xabcdef)
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<end/offset>: end of the memory region. It's possible to use +0x1234
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to specify the offset instead of the absolute address
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2005-11-07 04:15:40 -07:00
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2005-04-16 16:20:36 -06:00
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NOTE:
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tree-wide: fix assorted typos all over the place
That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-14 08:09:05 -07:00
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With slram it's only possible to map a contiguous memory region. Therefore
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2005-04-16 16:20:36 -06:00
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if there's a device mapped somewhere in the region specified slram will
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fail to load (see kernel log if modprobe fails).
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-
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2005-11-07 04:15:40 -07:00
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2005-04-16 16:20:36 -06:00
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Jochen Schaeuble <psionic@psionic.de>
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======================================================================*/
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#include <linux/module.h>
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#include <asm/uaccess.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/ptrace.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/timer.h>
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#include <linux/major.h>
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#include <linux/fs.h>
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#include <linux/ioctl.h>
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#include <linux/init.h>
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#include <asm/io.h>
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#include <asm/system.h>
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#include <linux/mtd/mtd.h>
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#define SLRAM_MAX_DEVICES_PARAMS 6 /* 3 parameters / device */
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2005-01-06 14:16:45 -07:00
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#define SLRAM_BLK_SZ 0x4000
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2005-04-16 16:20:36 -06:00
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#define T(fmt, args...) printk(KERN_DEBUG fmt, ## args)
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#define E(fmt, args...) printk(KERN_NOTICE fmt, ## args)
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typedef struct slram_priv {
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u_char *start;
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u_char *end;
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} slram_priv_t;
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typedef struct slram_mtd_list {
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struct mtd_info *mtdinfo;
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struct slram_mtd_list *next;
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} slram_mtd_list_t;
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#ifdef MODULE
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static char *map[SLRAM_MAX_DEVICES_PARAMS];
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module_param_array(map, charp, NULL, 0);
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MODULE_PARM_DESC(map, "List of memory regions to map. \"map=<name>, <start>, <length / end>\"");
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#else
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static char *map;
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#endif
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static slram_mtd_list_t *slram_mtdlist = NULL;
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static int slram_erase(struct mtd_info *, struct erase_info *);
|
2008-04-30 00:26:49 -06:00
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static int slram_point(struct mtd_info *, loff_t, size_t, size_t *, void **,
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resource_size_t *);
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static void slram_unpoint(struct mtd_info *, loff_t, size_t);
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2005-04-16 16:20:36 -06:00
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static int slram_read(struct mtd_info *, loff_t, size_t, size_t *, u_char *);
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static int slram_write(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
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static int slram_erase(struct mtd_info *mtd, struct erase_info *instr)
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{
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slram_priv_t *priv = mtd->priv;
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if (instr->addr + instr->len > mtd->size) {
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return(-EINVAL);
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}
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2005-11-07 04:15:40 -07:00
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2005-04-16 16:20:36 -06:00
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memset(priv->start + instr->addr, 0xff, instr->len);
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2005-11-07 04:15:40 -07:00
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/* This'll catch a few races. Free the thing before returning :)
|
2005-04-16 16:20:36 -06:00
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* I don't feel at all ashamed. This kind of thing is possible anyway
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* with flash, but unlikely.
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*/
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instr->state = MTD_ERASE_DONE;
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mtd_erase_callback(instr);
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return(0);
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}
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static int slram_point(struct mtd_info *mtd, loff_t from, size_t len,
|
2008-04-30 00:26:49 -06:00
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size_t *retlen, void **virt, resource_size_t *phys)
|
2005-04-16 16:20:36 -06:00
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{
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slram_priv_t *priv = mtd->priv;
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2008-04-30 00:26:49 -06:00
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/* can we return a physical address with this driver? */
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if (phys)
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return -EINVAL;
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2005-01-06 14:16:45 -07:00
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if (from + len > mtd->size)
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return -EINVAL;
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2008-04-30 00:26:49 -06:00
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*virt = priv->start + from;
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2005-04-16 16:20:36 -06:00
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|
*retlen = len;
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return(0);
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}
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2008-04-30 00:26:49 -06:00
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static void slram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
|
2005-04-16 16:20:36 -06:00
|
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|
{
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|
}
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|
static int slram_read(struct mtd_info *mtd, loff_t from, size_t len,
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size_t *retlen, u_char *buf)
|
|
|
|
{
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|
slram_priv_t *priv = mtd->priv;
|
2005-01-06 14:16:45 -07:00
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if (from > mtd->size)
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return -EINVAL;
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|
if (from + len > mtd->size)
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len = mtd->size - from;
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2005-04-16 16:20:36 -06:00
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memcpy(buf, priv->start + from, len);
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*retlen = len;
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return(0);
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}
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static int slram_write(struct mtd_info *mtd, loff_t to, size_t len,
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size_t *retlen, const u_char *buf)
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{
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slram_priv_t *priv = mtd->priv;
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2005-01-06 14:16:45 -07:00
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if (to + len > mtd->size)
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return -EINVAL;
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2005-04-16 16:20:36 -06:00
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memcpy(priv->start + to, buf, len);
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*retlen = len;
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return(0);
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}
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/*====================================================================*/
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static int register_device(char *name, unsigned long start, unsigned long length)
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{
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slram_mtd_list_t **curmtd;
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curmtd = &slram_mtdlist;
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while (*curmtd) {
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curmtd = &(*curmtd)->next;
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}
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*curmtd = kmalloc(sizeof(slram_mtd_list_t), GFP_KERNEL);
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if (!(*curmtd)) {
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E("slram: Cannot allocate new MTD device.\n");
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return(-ENOMEM);
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}
|
2006-11-15 12:10:29 -07:00
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(*curmtd)->mtdinfo = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
|
2005-04-16 16:20:36 -06:00
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(*curmtd)->next = NULL;
|
2005-11-07 04:15:40 -07:00
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2005-04-16 16:20:36 -06:00
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if ((*curmtd)->mtdinfo) {
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(*curmtd)->mtdinfo->priv =
|
2006-11-15 12:10:29 -07:00
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kzalloc(sizeof(slram_priv_t), GFP_KERNEL);
|
2005-11-07 04:15:40 -07:00
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2005-04-16 16:20:36 -06:00
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if (!(*curmtd)->mtdinfo->priv) {
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kfree((*curmtd)->mtdinfo);
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(*curmtd)->mtdinfo = NULL;
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}
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}
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if (!(*curmtd)->mtdinfo) {
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E("slram: Cannot allocate new MTD device.\n");
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return(-ENOMEM);
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}
|
2005-11-07 04:15:40 -07:00
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2005-04-16 16:20:36 -06:00
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if (!(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start =
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ioremap(start, length))) {
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|
|
E("slram: ioremap failed\n");
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|
return -EIO;
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|
|
}
|
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((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end =
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((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start + length;
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(*curmtd)->mtdinfo->name = name;
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(*curmtd)->mtdinfo->size = length;
|
2006-04-13 10:54:34 -06:00
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|
|
(*curmtd)->mtdinfo->flags = MTD_CAP_RAM;
|
2012-01-30 05:58:32 -07:00
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|
(*curmtd)->mtdinfo->_erase = slram_erase;
|
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|
|
(*curmtd)->mtdinfo->_point = slram_point;
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|
(*curmtd)->mtdinfo->_unpoint = slram_unpoint;
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|
(*curmtd)->mtdinfo->_read = slram_read;
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(*curmtd)->mtdinfo->_write = slram_write;
|
2005-04-16 16:20:36 -06:00
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|
(*curmtd)->mtdinfo->owner = THIS_MODULE;
|
2006-06-14 14:39:48 -06:00
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|
(*curmtd)->mtdinfo->type = MTD_RAM;
|
2005-01-06 14:16:45 -07:00
|
|
|
(*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;
|
2006-06-22 08:15:48 -06:00
|
|
|
(*curmtd)->mtdinfo->writesize = 1;
|
2005-04-16 16:20:36 -06:00
|
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|
2011-05-23 03:23:40 -06:00
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|
|
if (mtd_device_register((*curmtd)->mtdinfo, NULL, 0)) {
|
2005-04-16 16:20:36 -06:00
|
|
|
E("slram: Failed to register new device\n");
|
|
|
|
iounmap(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start);
|
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|
|
kfree((*curmtd)->mtdinfo->priv);
|
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|
|
kfree((*curmtd)->mtdinfo);
|
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|
|
return(-EAGAIN);
|
|
|
|
}
|
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|
|
T("slram: Registered device %s from %luKiB to %luKiB\n", name,
|
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|
|
(start / 1024), ((start + length) / 1024));
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|
T("slram: Mapped from 0x%p to 0x%p\n",
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|
|
((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start,
|
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|
|
((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end);
|
2005-11-07 04:15:40 -07:00
|
|
|
return(0);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static void unregister_devices(void)
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|
|
|
{
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|
|
|
slram_mtd_list_t *nextitem;
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|
|
|
|
|
|
while (slram_mtdlist) {
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|
|
nextitem = slram_mtdlist->next;
|
2011-05-23 03:23:40 -06:00
|
|
|
mtd_device_unregister(slram_mtdlist->mtdinfo);
|
2005-04-16 16:20:36 -06:00
|
|
|
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)
|
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|
|
{
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|
|
|
if ((*unit == 'M') || (*unit == 'm')) {
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|
|
return(value * 1024 * 1024);
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|
|
} else if ((*unit == 'K') || (*unit == 'k')) {
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|
|
|
return(value * 1024);
|
|
|
|
}
|
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|
|
return(value);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int parse_cmdline(char *devname, char *szstart, char *szlength)
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|
|
|
{
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|
|
|
char *buffer;
|
|
|
|
unsigned long devstart;
|
|
|
|
unsigned long devlength;
|
2005-11-07 04:15:40 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
if ((!devname) || (!szstart) || (!szlength)) {
|
|
|
|
unregister_devices();
|
|
|
|
return(-EINVAL);
|
|
|
|
}
|
|
|
|
|
|
|
|
devstart = simple_strtoul(szstart, &buffer, 0);
|
|
|
|
devstart = handle_unit(devstart, buffer);
|
2005-11-07 04:15:40 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
if (*(szlength) != '+') {
|
|
|
|
devlength = simple_strtoul(szlength, &buffer, 0);
|
|
|
|
devlength = handle_unit(devlength, buffer) - devstart;
|
2009-01-18 16:15:13 -07:00
|
|
|
if (devlength < devstart)
|
|
|
|
goto err_out;
|
|
|
|
|
|
|
|
devlength -= devstart;
|
2005-04-16 16:20:36 -06:00
|
|
|
} 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);
|
2009-01-18 16:15:13 -07:00
|
|
|
if (devlength % SLRAM_BLK_SZ != 0)
|
|
|
|
goto err_out;
|
2005-11-07 04:15:40 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
if ((devstart = register_device(devname, devstart, devlength))){
|
|
|
|
unregister_devices();
|
|
|
|
return((int)devstart);
|
|
|
|
}
|
|
|
|
return(0);
|
2009-01-18 16:15:13 -07:00
|
|
|
|
|
|
|
err_out:
|
|
|
|
E("slram: Illegal length parameter.\n");
|
|
|
|
return(-EINVAL);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
#ifndef MODULE
|
|
|
|
|
|
|
|
static int __init mtd_slram_setup(char *str)
|
|
|
|
{
|
|
|
|
map = str;
|
|
|
|
return(1);
|
|
|
|
}
|
|
|
|
|
|
|
|
__setup("slram=", mtd_slram_setup);
|
|
|
|
|
|
|
|
#endif
|
|
|
|
|
2009-06-10 18:23:33 -06:00
|
|
|
static int __init init_slram(void)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
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;
|
2005-11-07 04:15:40 -07:00
|
|
|
|
2009-07-31 06:47:58 -06:00
|
|
|
for (count = 0; count < SLRAM_MAX_DEVICES_PARAMS && map[count];
|
2005-04-16 16:20:36 -06:00
|
|
|
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);
|
|
|
|
}
|
2005-11-07 04:15:40 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
#endif /* !MODULE */
|
2005-11-07 04:15:40 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
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");
|