/* * $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $ * * Character-device access to raw MTD devices. * */ #include <linux/config.h> #include <linux/device.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/sched.h> #include <linux/mtd/mtd.h> #include <linux/mtd/compatmac.h> #include <asm/uaccess.h> static struct class *mtd_class; static void mtd_notify_add(struct mtd_info* mtd) { if (!mtd) return; class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2), NULL, "mtd%d", mtd->index); class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1), NULL, "mtd%dro", mtd->index); } static void mtd_notify_remove(struct mtd_info* mtd) { if (!mtd) return; class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2)); class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1)); } static struct mtd_notifier notifier = { .add = mtd_notify_add, .remove = mtd_notify_remove, }; /* * We use file->private_data to store a pointer to the MTDdevice. * Since alighment is at least 32 bits, we have 2 bits free for OTP * modes as well. */ #define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L) #define MTD_MODE_OTP_FACT 1 #define MTD_MODE_OTP_USER 2 #define MTD_MODE(file) ((long)((file)->private_data) & 3) #define SET_MTD_MODE(file, mode) \ do { long __p = (long)((file)->private_data); \ (file)->private_data = (void *)((__p & ~3L) | mode); } while (0) static loff_t mtd_lseek (struct file *file, loff_t offset, int orig) { struct mtd_info *mtd = TO_MTD(file); switch (orig) { case 0: /* SEEK_SET */ break; case 1: /* SEEK_CUR */ offset += file->f_pos; break; case 2: /* SEEK_END */ offset += mtd->size; break; default: return -EINVAL; } if (offset >= 0 && offset < mtd->size) return file->f_pos = offset; return -EINVAL; } static int mtd_open(struct inode *inode, struct file *file) { int minor = iminor(inode); int devnum = minor >> 1; struct mtd_info *mtd; DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n"); if (devnum >= MAX_MTD_DEVICES) return -ENODEV; /* You can't open the RO devices RW */ if ((file->f_mode & 2) && (minor & 1)) return -EACCES; mtd = get_mtd_device(NULL, devnum); if (!mtd) return -ENODEV; if (MTD_ABSENT == mtd->type) { put_mtd_device(mtd); return -ENODEV; } file->private_data = mtd; /* You can't open it RW if it's not a writeable device */ if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) { put_mtd_device(mtd); return -EACCES; } return 0; } /* mtd_open */ /*====================================================================*/ static int mtd_close(struct inode *inode, struct file *file) { struct mtd_info *mtd; DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n"); mtd = TO_MTD(file); if (mtd->sync) mtd->sync(mtd); put_mtd_device(mtd); return 0; } /* mtd_close */ /* FIXME: This _really_ needs to die. In 2.5, we should lock the userspace buffer down and use it directly with readv/writev. */ #define MAX_KMALLOC_SIZE 0x20000 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos) { struct mtd_info *mtd = TO_MTD(file); size_t retlen=0; size_t total_retlen=0; int ret=0; int len; char *kbuf; DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n"); if (*ppos + count > mtd->size) count = mtd->size - *ppos; if (!count) return 0; /* FIXME: Use kiovec in 2.5 to lock down the user's buffers and pass them directly to the MTD functions */ while (count) { if (count > MAX_KMALLOC_SIZE) len = MAX_KMALLOC_SIZE; else len = count; kbuf=kmalloc(len,GFP_KERNEL); if (!kbuf) return -ENOMEM; switch (MTD_MODE(file)) { case MTD_MODE_OTP_FACT: ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf); break; case MTD_MODE_OTP_USER: ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf); break; default: ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf); } /* Nand returns -EBADMSG on ecc errors, but it returns * the data. For our userspace tools it is important * to dump areas with ecc errors ! * Userspace software which accesses NAND this way * must be aware of the fact that it deals with NAND */ if (!ret || (ret == -EBADMSG)) { *ppos += retlen; if (copy_to_user(buf, kbuf, retlen)) { kfree(kbuf); return -EFAULT; } else total_retlen += retlen; count -= retlen; buf += retlen; if (retlen == 0) count = 0; } else { kfree(kbuf); return ret; } kfree(kbuf); } return total_retlen; } /* mtd_read */ static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos) { struct mtd_info *mtd = TO_MTD(file); char *kbuf; size_t retlen; size_t total_retlen=0; int ret=0; int len; DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n"); if (*ppos == mtd->size) return -ENOSPC; if (*ppos + count > mtd->size) count = mtd->size - *ppos; if (!count) return 0; while (count) { if (count > MAX_KMALLOC_SIZE) len = MAX_KMALLOC_SIZE; else len = count; kbuf=kmalloc(len,GFP_KERNEL); if (!kbuf) { printk("kmalloc is null\n"); return -ENOMEM; } if (copy_from_user(kbuf, buf, len)) { kfree(kbuf); return -EFAULT; } switch (MTD_MODE(file)) { case MTD_MODE_OTP_FACT: ret = -EROFS; break; case MTD_MODE_OTP_USER: if (!mtd->write_user_prot_reg) { ret = -EOPNOTSUPP; break; } ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf); break; default: ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf); } if (!ret) { *ppos += retlen; total_retlen += retlen; count -= retlen; buf += retlen; } else { kfree(kbuf); return ret; } kfree(kbuf); } return total_retlen; } /* mtd_write */ /*====================================================================== IOCTL calls for getting device parameters. ======================================================================*/ static void mtdchar_erase_callback (struct erase_info *instr) { wake_up((wait_queue_head_t *)instr->priv); } static int mtd_ioctl(struct inode *inode, struct file *file, u_int cmd, u_long arg) { struct mtd_info *mtd = TO_MTD(file); void __user *argp = (void __user *)arg; int ret = 0; u_long size; DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n"); size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT; if (cmd & IOC_IN) { if (!access_ok(VERIFY_READ, argp, size)) return -EFAULT; } if (cmd & IOC_OUT) { if (!access_ok(VERIFY_WRITE, argp, size)) return -EFAULT; } switch (cmd) { case MEMGETREGIONCOUNT: if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int))) return -EFAULT; break; case MEMGETREGIONINFO: { struct region_info_user ur; if (copy_from_user(&ur, argp, sizeof(struct region_info_user))) return -EFAULT; if (ur.regionindex >= mtd->numeraseregions) return -EINVAL; if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]), sizeof(struct mtd_erase_region_info))) return -EFAULT; break; } case MEMGETINFO: if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user))) return -EFAULT; break; case MEMERASE: { struct erase_info *erase; if(!(file->f_mode & 2)) return -EPERM; erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL); if (!erase) ret = -ENOMEM; else { wait_queue_head_t waitq; DECLARE_WAITQUEUE(wait, current); init_waitqueue_head(&waitq); memset (erase,0,sizeof(struct erase_info)); if (copy_from_user(&erase->addr, argp, sizeof(struct erase_info_user))) { kfree(erase); return -EFAULT; } erase->mtd = mtd; erase->callback = mtdchar_erase_callback; erase->priv = (unsigned long)&waitq; /* FIXME: Allow INTERRUPTIBLE. Which means not having the wait_queue head on the stack. If the wq_head is on the stack, and we leave because we got interrupted, then the wq_head is no longer there when the callback routine tries to wake us up. */ ret = mtd->erase(mtd, erase); if (!ret) { set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&waitq, &wait); if (erase->state != MTD_ERASE_DONE && erase->state != MTD_ERASE_FAILED) schedule(); remove_wait_queue(&waitq, &wait); set_current_state(TASK_RUNNING); ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0; } kfree(erase); } break; } case MEMWRITEOOB: { struct mtd_oob_buf buf; void *databuf; ssize_t retlen; if(!(file->f_mode & 2)) return -EPERM; if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf))) return -EFAULT; if (buf.length > 0x4096) return -EINVAL; if (!mtd->write_oob) ret = -EOPNOTSUPP; else ret = access_ok(VERIFY_READ, buf.ptr, buf.length) ? 0 : EFAULT; if (ret) return ret; databuf = kmalloc(buf.length, GFP_KERNEL); if (!databuf) return -ENOMEM; if (copy_from_user(databuf, buf.ptr, buf.length)) { kfree(databuf); return -EFAULT; } ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf); if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t))) ret = -EFAULT; kfree(databuf); break; } case MEMREADOOB: { struct mtd_oob_buf buf; void *databuf; ssize_t retlen; if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf))) return -EFAULT; if (buf.length > 0x4096) return -EINVAL; if (!mtd->read_oob) ret = -EOPNOTSUPP; else ret = access_ok(VERIFY_WRITE, buf.ptr, buf.length) ? 0 : -EFAULT; if (ret) return ret; databuf = kmalloc(buf.length, GFP_KERNEL); if (!databuf) return -ENOMEM; ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf); if (put_user(retlen, (uint32_t __user *)argp)) ret = -EFAULT; else if (retlen && copy_to_user(buf.ptr, databuf, retlen)) ret = -EFAULT; kfree(databuf); break; } case MEMLOCK: { struct erase_info_user info; if (copy_from_user(&info, argp, sizeof(info))) return -EFAULT; if (!mtd->lock) ret = -EOPNOTSUPP; else ret = mtd->lock(mtd, info.start, info.length); break; } case MEMUNLOCK: { struct erase_info_user info; if (copy_from_user(&info, argp, sizeof(info))) return -EFAULT; if (!mtd->unlock) ret = -EOPNOTSUPP; else ret = mtd->unlock(mtd, info.start, info.length); break; } case MEMSETOOBSEL: { if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo))) return -EFAULT; break; } case MEMGETOOBSEL: { if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo))) return -EFAULT; break; } case MEMGETBADBLOCK: { loff_t offs; if (copy_from_user(&offs, argp, sizeof(loff_t))) return -EFAULT; if (!mtd->block_isbad) ret = -EOPNOTSUPP; else return mtd->block_isbad(mtd, offs); break; } case MEMSETBADBLOCK: { loff_t offs; if (copy_from_user(&offs, argp, sizeof(loff_t))) return -EFAULT; if (!mtd->block_markbad) ret = -EOPNOTSUPP; else return mtd->block_markbad(mtd, offs); break; } #ifdef CONFIG_MTD_OTP case OTPSELECT: { int mode; if (copy_from_user(&mode, argp, sizeof(int))) return -EFAULT; SET_MTD_MODE(file, 0); switch (mode) { case MTD_OTP_FACTORY: if (!mtd->read_fact_prot_reg) ret = -EOPNOTSUPP; else SET_MTD_MODE(file, MTD_MODE_OTP_FACT); break; case MTD_OTP_USER: if (!mtd->read_fact_prot_reg) ret = -EOPNOTSUPP; else SET_MTD_MODE(file, MTD_MODE_OTP_USER); break; default: ret = -EINVAL; case MTD_OTP_OFF: break; } file->f_pos = 0; break; } case OTPGETREGIONCOUNT: case OTPGETREGIONINFO: { struct otp_info *buf = kmalloc(4096, GFP_KERNEL); if (!buf) return -ENOMEM; ret = -EOPNOTSUPP; switch (MTD_MODE(file)) { case MTD_MODE_OTP_FACT: if (mtd->get_fact_prot_info) ret = mtd->get_fact_prot_info(mtd, buf, 4096); break; case MTD_MODE_OTP_USER: if (mtd->get_user_prot_info) ret = mtd->get_user_prot_info(mtd, buf, 4096); break; } if (ret >= 0) { if (cmd == OTPGETREGIONCOUNT) { int nbr = ret / sizeof(struct otp_info); ret = copy_to_user(argp, &nbr, sizeof(int)); } else ret = copy_to_user(argp, buf, ret); if (ret) ret = -EFAULT; } kfree(buf); break; } case OTPLOCK: { struct otp_info info; if (MTD_MODE(file) != MTD_MODE_OTP_USER) return -EINVAL; if (copy_from_user(&info, argp, sizeof(info))) return -EFAULT; if (!mtd->lock_user_prot_reg) return -EOPNOTSUPP; ret = mtd->lock_user_prot_reg(mtd, info.start, info.length); break; } #endif default: ret = -ENOTTY; } return ret; } /* memory_ioctl */ static struct file_operations mtd_fops = { .owner = THIS_MODULE, .llseek = mtd_lseek, .read = mtd_read, .write = mtd_write, .ioctl = mtd_ioctl, .open = mtd_open, .release = mtd_close, }; static int __init init_mtdchar(void) { if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) { printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n", MTD_CHAR_MAJOR); return -EAGAIN; } mtd_class = class_create(THIS_MODULE, "mtd"); if (IS_ERR(mtd_class)) { printk(KERN_ERR "Error creating mtd class.\n"); unregister_chrdev(MTD_CHAR_MAJOR, "mtd"); return PTR_ERR(mtd_class); } register_mtd_user(¬ifier); return 0; } static void __exit cleanup_mtdchar(void) { unregister_mtd_user(¬ifier); class_destroy(mtd_class); unregister_chrdev(MTD_CHAR_MAJOR, "mtd"); } module_init(init_mtdchar); module_exit(cleanup_mtdchar); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); MODULE_DESCRIPTION("Direct character-device access to MTD devices");