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1/*2 * mtdram - a test mtd device3 * Author: Alexander Larsson <alex@cendio.se>4 *5 * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>6 * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>7 *8 * This code is GPL9 *10 */11 12#include <linux/module.h>13#include <linux/slab.h>14#include <linux/ioport.h>15#include <linux/vmalloc.h>16#include <linux/mm.h>17#include <linux/init.h>18#include <linux/mtd/mtd.h>19#include <linux/mtd/mtdram.h>20 21static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;22static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;23static unsigned long writebuf_size = 64;24#define MTDRAM_TOTAL_SIZE (total_size * 1024)25#define MTDRAM_ERASE_SIZE (erase_size * 1024)26 27module_param(total_size, ulong, 0);28MODULE_PARM_DESC(total_size, "Total device size in KiB");29module_param(erase_size, ulong, 0);30MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");31module_param(writebuf_size, ulong, 0);32MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)");33 34// We could store these in the mtd structure, but we only support 1 device..35static struct mtd_info *mtd_info;36 37static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)38{39 int ret = 0;40 41 /* Start address must align on block boundary */42 if (mtd_mod_by_eb(ofs, mtd)) {43 pr_debug("%s: unaligned address\n", __func__);44 ret = -EINVAL;45 }46 47 /* Length must align on block boundary */48 if (mtd_mod_by_eb(len, mtd)) {49 pr_debug("%s: length not block aligned\n", __func__);50 ret = -EINVAL;51 }52 53 return ret;54}55 56static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)57{58 if (check_offs_len(mtd, instr->addr, instr->len))59 return -EINVAL;60 memset((char *)mtd->priv + instr->addr, 0xff, instr->len);61 62 return 0;63}64 65static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,66 size_t *retlen, void **virt, resource_size_t *phys)67{68 *virt = mtd->priv + from;69 *retlen = len;70 71 if (phys) {72 /* limit retlen to the number of contiguous physical pages */73 unsigned long page_ofs = offset_in_page(*virt);74 void *addr = *virt - page_ofs;75 unsigned long pfn1, pfn0 = vmalloc_to_pfn(addr);76 77 *phys = __pfn_to_phys(pfn0) + page_ofs;78 len += page_ofs;79 while (len > PAGE_SIZE) {80 len -= PAGE_SIZE;81 addr += PAGE_SIZE;82 pfn0++;83 pfn1 = vmalloc_to_pfn(addr);84 if (pfn1 != pfn0) {85 *retlen = addr - *virt;86 break;87 }88 }89 }90 91 return 0;92}93 94static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)95{96 return 0;97}98 99static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,100 size_t *retlen, u_char *buf)101{102 memcpy(buf, mtd->priv + from, len);103 *retlen = len;104 return 0;105}106 107static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,108 size_t *retlen, const u_char *buf)109{110 memcpy((char *)mtd->priv + to, buf, len);111 *retlen = len;112 return 0;113}114 115static void __exit cleanup_mtdram(void)116{117 if (mtd_info) {118 mtd_device_unregister(mtd_info);119 vfree(mtd_info->priv);120 kfree(mtd_info);121 }122}123 124int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,125 unsigned long size, const char *name)126{127 memset(mtd, 0, sizeof(*mtd));128 129 /* Setup the MTD structure */130 mtd->name = name;131 mtd->type = MTD_RAM;132 mtd->flags = MTD_CAP_RAM;133 mtd->size = size;134 mtd->writesize = 1;135 mtd->writebufsize = writebuf_size;136 mtd->erasesize = MTDRAM_ERASE_SIZE;137 mtd->priv = mapped_address;138 139 mtd->owner = THIS_MODULE;140 mtd->_erase = ram_erase;141 mtd->_point = ram_point;142 mtd->_unpoint = ram_unpoint;143 mtd->_read = ram_read;144 mtd->_write = ram_write;145 146 if (mtd_device_register(mtd, NULL, 0))147 return -EIO;148 149 return 0;150}151 152static int __init init_mtdram(void)153{154 void *addr;155 int err;156 157 if (!total_size)158 return -EINVAL;159 160 /* Allocate some memory */161 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);162 if (!mtd_info)163 return -ENOMEM;164 165 addr = vmalloc(MTDRAM_TOTAL_SIZE);166 if (!addr) {167 kfree(mtd_info);168 mtd_info = NULL;169 return -ENOMEM;170 }171 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");172 if (err) {173 vfree(addr);174 kfree(mtd_info);175 mtd_info = NULL;176 return err;177 }178 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);179 return err;180}181 182module_init(init_mtdram);183module_exit(cleanup_mtdram);184 185MODULE_LICENSE("GPL");186MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");187MODULE_DESCRIPTION("Simulated MTD driver for testing");188