/* * mtdram - a test mtd device * Author: Alexander Larsson <alex@cendio.se> * * Copyright (c) 1999 Alexander Larsson <alex@cendio.se> * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de> * * This code is GPL * */ #include <linux/module.h> #include <linux/slab.h> #include <linux/ioport.h> #include <linux/vmalloc.h> #include <linux/mm.h> #include <linux/init.h> #include <linux/mtd/mtd.h> #include <linux/mtd/mtdram.h> static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE; static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE; static unsigned long writebuf_size = 64; #define MTDRAM_TOTAL_SIZE (total_size * 1024) #define MTDRAM_ERASE_SIZE (erase_size * 1024) #ifdef MODULE module_param(total_size, ulong, 0); MODULE_PARM_DESC(total_size, "Total device size in KiB"); module_param(erase_size, ulong, 0); MODULE_PARM_DESC(erase_size, "Device erase block size in KiB"); module_param(writebuf_size, ulong, 0); MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)"); #endif // We could store these in the mtd structure, but we only support 1 device.. static struct mtd_info *mtd_info; static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len) { int ret = 0; /* Start address must align on block boundary */ if (mtd_mod_by_eb(ofs, mtd)) { pr_debug("%s: unaligned address\n", __func__); ret = -EINVAL; } /* Length must align on block boundary */ if (mtd_mod_by_eb(len, mtd)) { pr_debug("%s: length not block aligned\n", __func__); ret = -EINVAL; } return ret; } static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) { if (check_offs_len(mtd, instr->addr, instr->len)) return -EINVAL; memset((char *)mtd->priv + instr->addr, 0xff, instr->len); return 0; } static int ram_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, void **virt, resource_size_t *phys) { *virt = mtd->priv + from; *retlen = len; if (phys) { /* limit retlen to the number of contiguous physical pages */ unsigned long page_ofs = offset_in_page(*virt); void *addr = *virt - page_ofs; unsigned long pfn1, pfn0 = vmalloc_to_pfn(addr); *phys = __pfn_to_phys(pfn0) + page_ofs; len += page_ofs; while (len > PAGE_SIZE) { len -= PAGE_SIZE; addr += PAGE_SIZE; pfn0++; pfn1 = vmalloc_to_pfn(addr); if (pfn1 != pfn0) { *retlen = addr - *virt; break; } } } return 0; } static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) { return 0; } static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { memcpy(buf, mtd->priv + from, len); *retlen = len; return 0; } static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { memcpy((char *)mtd->priv + to, buf, len); *retlen = len; return 0; } static void __exit cleanup_mtdram(void) { if (mtd_info) { mtd_device_unregister(mtd_info); vfree(mtd_info->priv); kfree(mtd_info); } } int mtdram_init_device(struct mtd_info *mtd, void *mapped_address, unsigned long size, const char *name) { memset(mtd, 0, sizeof(*mtd)); /* Setup the MTD structure */ mtd->name = name; mtd->type = MTD_RAM; mtd->flags = MTD_CAP_RAM; mtd->size = size; mtd->writesize = 1; mtd->writebufsize = writebuf_size; mtd->erasesize = MTDRAM_ERASE_SIZE; mtd->priv = mapped_address; mtd->owner = THIS_MODULE; mtd->_erase = ram_erase; mtd->_point = ram_point; mtd->_unpoint = ram_unpoint; mtd->_read = ram_read; mtd->_write = ram_write; if (mtd_device_register(mtd, NULL, 0)) return -EIO; return 0; } static int __init init_mtdram(void) { void *addr; int err; if (!total_size) return -EINVAL; /* Allocate some memory */ mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL); if (!mtd_info) return -ENOMEM; addr = vmalloc(MTDRAM_TOTAL_SIZE); if (!addr) { kfree(mtd_info); mtd_info = NULL; return -ENOMEM; } err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device"); if (err) { vfree(addr); kfree(mtd_info); mtd_info = NULL; return err; } memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE); return err; } module_init(init_mtdram); module_exit(cleanup_mtdram); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>"); MODULE_DESCRIPTION("Simulated MTD driver for testing");