cregit-Linux how code gets into the kernel

Release 4.7 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; }

Contributors

PersonTokensPropCommitsCommitProp
mikael starvikmikael starvik41100.00%1100.00%
Total41100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
mikael starvikmikael starvik41100.00%1100.00%
Total41100.00%1100.00%


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]; }

Contributors

PersonTokensPropCommitsCommitProp
mikael starvikmikael starvik41100.00%1100.00%
Total41100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
mikael starvikmikael starvik7094.59%150.00%
jesper nilssonjesper nilsson45.41%150.00%
Total74100.00%2100.00%

/* * 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 boundaries. * * 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; }

Contributors

PersonTokensPropCommitsCommitProp
mikael starvikmikael starvik15698.11%150.00%
jesper nilssonjesper nilsson31.89%150.00%
Total159100.00%2100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
jesper nilssonjesper nilsson63357.55%228.57%
mikael starvikmikael starvik46041.82%114.29%
jamie ilesjamie iles30.27%114.29%
artem bityutskiyartem bityutskiy20.18%228.57%
andy shevchenkoandy shevchenko20.18%114.29%
Total1100100.00%7100.00%

/* This adds the above to the kernels init-call chain. */ module_init(init_axis_flash); EXPORT_SYMBOL(axisflash_mtd);

Overall Contributors

PersonTokensPropCommitsCommitProp
mikael starvikmikael starvik118058.27%19.09%
jesper nilssonjesper nilsson83341.14%327.27%
jamie ilesjamie iles30.15%19.09%
tim schmielautim schmielau30.15%19.09%
andy shevchenkoandy shevchenko20.10%19.09%
artem bityutskiyartem bityutskiy20.10%218.18%
adam buchbinderadam buchbinder10.05%19.09%
lucas de marchilucas de marchi10.05%19.09%
Total2025100.00%11100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}