- 根目录:
- arch
- cris
- arch-v32
- drivers
- axisflashmap.c
/*
* Physical mapping layer for MTD using the Axis partitiontable format
*
* Copyright (c) 2001-2007 Axis Communications AB
*
* This file is under the GPL.
*
* First partition is always sector 0 regardless of if we find a partitiontable
* or not. In the start of the next sector, there can be a partitiontable that
* tells us what other partitions to define. If there isn't, we use a default
* partition split defined below.
*
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/mtd/concat.h>
#include <linux/mtd/map.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/mtdram.h>
#include <linux/mtd/partitions.h>
#include <asm/axisflashmap.h>
#include <asm/mmu.h>
#define MEM_CSE0_SIZE (0x04000000)
#define MEM_CSE1_SIZE (0x04000000)
#define FLASH_UNCACHED_ADDR KSEG_E
#define FLASH_CACHED_ADDR KSEG_F
#define PAGESIZE (512)
#if CONFIG_ETRAX_FLASH_BUSWIDTH==1
#define flash_data __u8
#elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
#define flash_data __u16
#elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
#define flash_data __u32
#endif
/* From head.S */
extern unsigned long romfs_in_flash; /* 1 when romfs_start, _length in flash */
extern unsigned long romfs_start, romfs_length;
extern unsigned long nand_boot; /* 1 when booted from nand flash */
struct partition_name {
char name[6];
};
/* The master mtd for the entire flash. */
struct mtd_info* axisflash_mtd = NULL;
/* Map driver functions. */
static map_word flash_read(struct map_info *map, unsigned long ofs)
{
map_word tmp;
tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
return tmp;
}
static void flash_copy_from(struct map_info *map, void *to,
unsigned long from, ssize_t len)
{
memcpy(to, (void *)(map->map_priv_1 + from), len);
}
static void flash_write(struct map_info *map, map_word d, unsigned long adr)
{
*(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
}
/*
* The map for chip select e0.
*
* We run into tricky coherence situations if we mix cached with uncached
* accesses to we only use the uncached version here.
*
* The size field is the total size where the flash chips may be mapped on the
* chip select. MTD probes should find all devices there and it does not matter
* if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
* probes will ignore them.
*
* The start address in map_priv_1 is in virtual memory so we cannot use
* MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
* address of cse0.
*/
static struct map_info map_cse0 = {
.name = "cse0",
.size = MEM_CSE0_SIZE,
.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
.read = flash_read,
.copy_from = flash_copy_from,
.write = flash_write,
.map_priv_1 = FLASH_UNCACHED_ADDR
};
/*
* The map for chip select e1.
*
* If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
* address, but there isn't.
*/
static struct map_info map_cse1 = {
.name = "cse1",
.size = MEM_CSE1_SIZE,
.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
.read = flash_read,
.copy_from = flash_copy_from,
.write = flash_write,
.map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
};
#define MAX_PARTITIONS 7
#ifdef CONFIG_ETRAX_NANDBOOT
#define NUM_DEFAULT_PARTITIONS 4
#define DEFAULT_ROOTFS_PARTITION_NO 2
#define DEFAULT_MEDIA_SIZE 0x2000000 /* 32 megs */
#else
#define NUM_DEFAULT_PARTITIONS 3
#define DEFAULT_ROOTFS_PARTITION_NO (-1)
#define DEFAULT_MEDIA_SIZE 0x800000 /* 8 megs */
#endif
#if (MAX_PARTITIONS < NUM_DEFAULT_PARTITIONS)
#error MAX_PARTITIONS must be >= than NUM_DEFAULT_PARTITIONS
#endif
/* Initialize the ones normally used. */
static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
{
.name = "part0",
.size = CONFIG_ETRAX_PTABLE_SECTOR,
.offset = 0
},
{
.name = "part1",
.size = 0,
.offset = 0
},
{
.name = "part2",
.size = 0,
.offset = 0
},
{
.name = "part3",
.size = 0,
.offset = 0
},
{
.name = "part4",
.size = 0,
.offset = 0
},
{
.name = "part5",
.size = 0,
.offset = 0
},
{
.name = "part6",
.size = 0,
.offset = 0
},
};
/* If no partition-table was found, we use this default-set.
* Default flash size is 8MB (NOR). CONFIG_ETRAX_PTABLE_SECTOR is most
* likely the size of one flash block and "filesystem"-partition needs
* to be >=5 blocks to be able to use JFFS.
*/
static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
{
.name = "boot firmware",
.size = CONFIG_ETRAX_PTABLE_SECTOR,
.offset = 0
},
{
.name = "kernel",
.size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
.offset = CONFIG_ETRAX_PTABLE_SECTOR
},
#define FILESYSTEM_SECTOR (11 * CONFIG_ETRAX_PTABLE_SECTOR)
#ifdef CONFIG_ETRAX_NANDBOOT
{
.name = "rootfs",
.size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
.offset = FILESYSTEM_SECTOR
},
#undef FILESYSTEM_SECTOR
#define FILESYSTEM_SECTOR (21 * CONFIG_ETRAX_PTABLE_SECTOR)
#endif
{
.name = "rwfs",
.size = DEFAULT_MEDIA_SIZE - FILESYSTEM_SECTOR,
.offset = FILESYSTEM_SECTOR
}
};
#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
/* Main flash device */
static struct mtd_partition main_partition = {
.name = "main",
.size = 0,
.offset = 0
};
#endif
/* Auxiliary partition if we find another flash */
static struct mtd_partition aux_partition = {
.name = "aux",
.size = 0,
.offset = 0
};
/*
* Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
* chips in that order (because the amd_flash-driver is faster).
*/
static struct mtd_info *probe_cs(struct map_info *map_cs)
{
struct mtd_info *mtd_cs = NULL;
printk(KERN_INFO
"%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
map_cs->name, map_cs->size, map_cs->map_priv_1);
#ifdef CONFIG_MTD_CFI
mtd_cs = do_map_probe("cfi_probe", map_cs);
#endif
#ifdef CONFIG_MTD_JEDECPROBE
if (!mtd_cs)
mtd_cs = do_map_probe("jedec_probe", map_cs);
#endif
return mtd_cs;
}
/*
* Probe each chip select individually for flash chips. If there are chips on
* both cse0 and cse1, the mtd_info structs will be concatenated to one struct
* so that MTD partitions can cross chip boundries.
*
* The only known restriction to how you can mount your chips is that each
* chip select must hold similar flash chips. But you need external hardware
* to do that anyway and you can put totally different chips on cse0 and cse1
* so it isn't really much of a restriction.
*/
extern struct mtd_info* __init crisv32_nand_flash_probe (void);
static struct mtd_info *flash_probe(void)
{
struct mtd_info *mtd_cse0;
struct mtd_info *mtd_cse1;
struct mtd_info *mtd_total;
struct mtd_info *mtds[2];
int count = 0;
if ((mtd_cse0 = probe_cs(&map_cse0)) != NULL)
mtds[count++] = mtd_cse0;
if ((mtd_cse1 = probe_cs(&map_cse1)) != NULL)
mtds[count++] = mtd_cse1;
if (!mtd_cse0 && !mtd_cse1) {
/* No chip found. */
return NULL;
}
if (count > 1) {
/* Since the concatenation layer adds a small overhead we
* could try to figure out if the chips in cse0 and cse1 are
* identical and reprobe the whole cse0+cse1 window. But since
* flash chips are slow, the overhead is relatively small.
* So we use the MTD concatenation layer instead of further
* complicating the probing procedure.
*/
mtd_total = mtd_concat_create(mtds, count, "cse0+cse1");
if (!mtd_total) {
printk(KERN_ERR "%s and %s: Concatenation failed!\n",
map_cse0.name, map_cse1.name);
/* The best we can do now is to only use what we found
* at cse0. */
mtd_total = mtd_cse0;
map_destroy(mtd_cse1);
}
} else
mtd_total = mtd_cse0 ? mtd_cse0 : mtd_cse1;
return mtd_total;
}
/*
* Probe the flash chip(s) and, if it succeeds, read the partition-table
* and register the partitions with MTD.
*/
static int __init init_axis_flash(void)
{
struct mtd_info *main_mtd;
struct mtd_info *aux_mtd = NULL;
int err = 0;
int pidx = 0;
struct partitiontable_head *ptable_head = NULL;
struct partitiontable_entry *ptable;
int ptable_ok = 0;
static char page[PAGESIZE];
size_t len;
int ram_rootfs_partition = -1; /* -1 => no RAM rootfs partition */
int part;
struct mtd_partition *partition;
/* We need a root fs. If it resides in RAM, we need to use an
* MTDRAM device, so it must be enabled in the kernel config,
* but its size must be configured as 0 so as not to conflict
* with our usage.
*/
#if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
if (!romfs_in_flash && !nand_boot) {
printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
"device; configure CONFIG_MTD_MTDRAM with size = 0!\n");
panic("This kernel cannot boot from RAM!\n");
}
#endif
main_mtd = flash_probe();
if (main_mtd)
printk(KERN_INFO "%s: 0x%08llx bytes of NOR flash memory.\n",
main_mtd->name, main_mtd->size);
#ifdef CONFIG_ETRAX_NANDFLASH
aux_mtd = crisv32_nand_flash_probe();
if (aux_mtd)
printk(KERN_INFO "%s: 0x%08x bytes of NAND flash memory.\n",
aux_mtd->name, aux_mtd->size);
#ifdef CONFIG_ETRAX_NANDBOOT
{
struct mtd_info *tmp_mtd;
printk(KERN_INFO "axisflashmap: Set to boot from NAND flash, "
"making NAND flash primary device.\n");
tmp_mtd = main_mtd;
main_mtd = aux_mtd;
aux_mtd = tmp_mtd;
}
#endif /* CONFIG_ETRAX_NANDBOOT */
#endif /* CONFIG_ETRAX_NANDFLASH */
if (!main_mtd && !aux_mtd) {
/* There's no reason to use this module if no flash chip can
* be identified. Make sure that's understood.
*/
printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
}
#if 0 /* Dump flash memory so we can see what is going on */
if (main_mtd) {
int sectoraddr;
for (sectoraddr = 0; sectoraddr < 2*65536+4096;
sectoraddr += PAGESIZE) {
main_mtd->read(main_mtd, sectoraddr, PAGESIZE, &len,
page);
printk(KERN_INFO
"Sector at %d (length %d):\n",
sectoraddr, len);
print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, page, PAGESIZE, false);
}
}
#endif
if (main_mtd) {
loff_t ptable_sector = CONFIG_ETRAX_PTABLE_SECTOR;
main_mtd->owner = THIS_MODULE;
axisflash_mtd = main_mtd;
/* First partition (rescue) is always set to the default. */
pidx++;
#ifdef CONFIG_ETRAX_NANDBOOT
/* We know where the partition table should be located,
* it will be in first good block after that.
*/
int blockstat;
do {
blockstat = mtd_block_isbad(main_mtd, ptable_sector);
if (blockstat < 0)
ptable_sector = 0; /* read error */
else if (blockstat)
ptable_sector += main_mtd->erasesize;
} while (blockstat && ptable_sector);
#endif
if (ptable_sector) {
mtd_read(main_mtd, ptable_sector, PAGESIZE, &len,
page);
ptable_head = &((struct partitiontable *) page)->head;
}
#if 0 /* Dump partition table so we can see what is going on */
printk(KERN_INFO
"axisflashmap: flash read %d bytes at 0x%08x, data: %8ph\n",
len, CONFIG_ETRAX_PTABLE_SECTOR, page);
printk(KERN_INFO
"axisflashmap: partition table offset %d, data: %8ph\n",
PARTITION_TABLE_OFFSET, page + PARTITION_TABLE_OFFSET);
#endif
}
if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
&& (ptable_head->size <
(MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
PARTITIONTABLE_END_MARKER_SIZE))
&& (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
ptable_head->size -
PARTITIONTABLE_END_MARKER_SIZE)
== PARTITIONTABLE_END_MARKER)) {
/* Looks like a start, sane length and end of a
* partition table, lets check csum etc.
*/
struct partitiontable_entry *max_addr =
(struct partitiontable_entry *)
((unsigned long)ptable_head + sizeof(*ptable_head) +
ptable_head->size);
unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
unsigned char *p;
unsigned long csum = 0;
ptable = (struct partitiontable_entry *)
((unsigned long)ptable_head + sizeof(*ptable_head));
/* Lets be PARANOID, and check the checksum. */
p = (unsigned char*) ptable;
while (p <= (unsigned char*)max_addr) {
csum += *p++;
csum += *p++;
csum += *p++;
csum += *p++;
}
ptable_ok = (csum == ptable_head->checksum);
/* Read the entries and use/show the info. */
printk(KERN_INFO "axisflashmap: "
"Found a%s partition table at 0x%p-0x%p.\n",
(ptable_ok ? " valid" : "n invalid"), ptable_head,
max_addr);
/* We have found a working bootblock. Now read the
* partition table. Scan the table. It ends with 0xffffffff.
*/
while (ptable_ok
&& ptable->offset != PARTITIONTABLE_END_MARKER
&& ptable < max_addr
&& pidx < MAX_PARTITIONS - 1) {
axis_partitions[pidx].offset = offset + ptable->offset;
#ifdef CONFIG_ETRAX_NANDFLASH
if (main_mtd->type == MTD_NANDFLASH) {
axis_partitions[pidx].size =
(((ptable+1)->offset ==
PARTITIONTABLE_END_MARKER) ?
main_mtd->size :
((ptable+1)->offset + offset)) -
(ptable->offset + offset);
} else
#endif /* CONFIG_ETRAX_NANDFLASH */
axis_partitions[pidx].size = ptable->size;
#ifdef CONFIG_ETRAX_NANDBOOT
/* Save partition number of jffs2 ro partition.
* Needed if RAM booting or root file system in RAM.
*/
if (!nand_boot &&
ram_rootfs_partition < 0 && /* not already set */
ptable->type == PARTITION_TYPE_JFFS2 &&
(ptable->flags & PARTITION_FLAGS_READONLY_MASK) ==
PARTITION_FLAGS_READONLY)
ram_rootfs_partition = pidx;
#endif /* CONFIG_ETRAX_NANDBOOT */
pidx++;
ptable++;
}
}
/* Decide whether to use default partition table. */
/* Only use default table if we actually have a device (main_mtd) */
partition = &axis_partitions[0];
if (main_mtd && !ptable_ok) {
memcpy(axis_partitions, axis_default_partitions,
sizeof(axis_default_partitions));
pidx = NUM_DEFAULT_PARTITIONS;
ram_rootfs_partition = DEFAULT_ROOTFS_PARTITION_NO;
}
/* Add artificial partitions for rootfs if necessary */
if (romfs_in_flash) {
/* rootfs is in directly accessible flash memory = NOR flash.
Add an overlapping device for the rootfs partition. */
printk(KERN_INFO "axisflashmap: Adding partition for "
"overlapping root file system image\n");
axis_partitions[pidx].size = romfs_length;
axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
axis_partitions[pidx].name = "romfs";
axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
ram_rootfs_partition = -1;
pidx++;
} else if (romfs_length && !nand_boot) {
/* romfs exists in memory, but not in flash, so must be in RAM.
* Configure an MTDRAM partition. */
if (ram_rootfs_partition < 0) {
/* None set yet, put it at the end */
ram_rootfs_partition = pidx;
pidx++;
}
printk(KERN_INFO "axisflashmap: Adding partition for "
"root file system image in RAM\n");
axis_partitions[ram_rootfs_partition].size = romfs_length;
axis_partitions[ram_rootfs_partition].offset = romfs_start;
axis_partitions[ram_rootfs_partition].name = "romfs";
axis_partitions[ram_rootfs_partition].mask_flags |=
MTD_WRITEABLE;
}
#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
if (main_mtd) {
main_partition.size = main_mtd->size;
err = mtd_device_register(main_mtd, &main_partition, 1);
if (err)
panic("axisflashmap: Could not initialize "
"partition for whole main mtd device!\n");
}
#endif
/* Now, register all partitions with mtd.
* We do this one at a time so we can slip in an MTDRAM device
* in the proper place if required. */
for (part = 0; part < pidx; part++) {
if (part == ram_rootfs_partition) {
/* add MTDRAM partition here */
struct mtd_info *mtd_ram;
mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
if (!mtd_ram)
panic("axisflashmap: Couldn't allocate memory "
"for mtd_info!\n");
printk(KERN_INFO "axisflashmap: Adding RAM partition "
"for rootfs image.\n");
err = mtdram_init_device(mtd_ram,
(void *)(u_int32_t)partition[part].offset,
partition[part].size,
partition[part].name);
if (err)
panic("axisflashmap: Could not initialize "
"MTD RAM device!\n");
/* JFFS2 likes to have an erasesize. Keep potential
* JFFS2 rootfs happy by providing one. Since image
* was most likely created for main mtd, use that
* erasesize, if available. Otherwise, make a guess. */
mtd_ram->erasesize = (main_mtd ? main_mtd->erasesize :
CONFIG_ETRAX_PTABLE_SECTOR);
} else {
err = mtd_device_register(main_mtd, &partition[part],
1);
if (err)
panic("axisflashmap: Could not add mtd "
"partition %d\n", part);
}
}
if (aux_mtd) {
aux_partition.size = aux_mtd->size;
err = mtd_device_register(aux_mtd, &aux_partition, 1);
if (err)
panic("axisflashmap: Could not initialize "
"aux mtd device!\n");
}
return err;
}
/* This adds the above to the kernels init-call chain. */
module_init(init_axis_flash);
EXPORT_SYMBOL(axisflash_mtd);