mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
344 lines
8.5 KiB
344 lines
8.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/*====================================================================== |
|
|
|
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 <[email protected]> |
|
|
|
======================================================================*/ |
|
|
|
|
|
#include <linux/module.h> |
|
#include <linux/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 <linux/io.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; |
|
|
|
memset(priv->start + instr->addr, 0xff, instr->len); |
|
|
|
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; |
|
|
|
*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; |
|
|
|
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; |
|
|
|
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 = |
|
memremap(start, length, |
|
MEMREMAP_WB | MEMREMAP_WT | MEMREMAP_WC))) { |
|
E("slram: memremap 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"); |
|
memunmap(((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); |
|
memunmap(((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); |
|
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; |
|
|
|
#ifndef MODULE |
|
char *devstart; |
|
char *devlength; |
|
|
|
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; |
|
int i; |
|
|
|
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 <[email protected]>"); |
|
MODULE_DESCRIPTION("MTD driver for uncached system RAM");
|
|
|