+
+void put_mtd_device(struct mtd_info *mtd)
+{
+ mutex_lock(&mtd_table_mutex);
+ __put_mtd_device(mtd);
+ mutex_unlock(&mtd_table_mutex);
+
+}
+EXPORT_SYMBOL_GPL(put_mtd_device);
+
+void __put_mtd_device(struct mtd_info *mtd)
+{
+ --mtd->usecount;
+ BUG_ON(mtd->usecount < 0);
+
+ if (mtd->_put_device)
+ mtd->_put_device(mtd);
+
+ module_put(mtd->owner);
+}
+EXPORT_SYMBOL_GPL(__put_mtd_device);
+
+/*
+ * Erase is an asynchronous operation. Device drivers are supposed
+ * to call instr->callback() whenever the operation completes, even
+ * if it completes with a failure.
+ * Callers are supposed to pass a callback function and wait for it
+ * to be called before writing to the block.
+ */
+int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+ if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
+ return -EINVAL;
+ if (!(mtd->flags & MTD_WRITEABLE))
+ return -EROFS;
+ instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
+ if (!instr->len) {
+ instr->state = MTD_ERASE_DONE;
+ mtd_erase_callback(instr);
+ return 0;
+ }
+ return mtd->_erase(mtd, instr);
+}
+EXPORT_SYMBOL_GPL(mtd_erase);
+
+#ifndef __UBOOT__
+/*
+ * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
+ */
+int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
+ void **virt, resource_size_t *phys)
+{
+ *retlen = 0;
+ *virt = NULL;
+ if (phys)
+ *phys = 0;
+ if (!mtd->_point)
+ return -EOPNOTSUPP;
+ if (from < 0 || from > mtd->size || len > mtd->size - from)
+ return -EINVAL;
+ if (!len)
+ return 0;
+ return mtd->_point(mtd, from, len, retlen, virt, phys);
+}
+EXPORT_SYMBOL_GPL(mtd_point);
+
+/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
+int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+ if (!mtd->_point)
+ return -EOPNOTSUPP;
+ if (from < 0 || from > mtd->size || len > mtd->size - from)
+ return -EINVAL;
+ if (!len)
+ return 0;
+ return mtd->_unpoint(mtd, from, len);
+}
+EXPORT_SYMBOL_GPL(mtd_unpoint);
+#endif
+
+/*
+ * Allow NOMMU mmap() to directly map the device (if not NULL)
+ * - return the address to which the offset maps
+ * - return -ENOSYS to indicate refusal to do the mapping
+ */
+unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
+ unsigned long offset, unsigned long flags)
+{
+ if (!mtd->_get_unmapped_area)
+ return -EOPNOTSUPP;
+ if (offset > mtd->size || len > mtd->size - offset)
+ return -EINVAL;
+ return mtd->_get_unmapped_area(mtd, len, offset, flags);
+}
+EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
+
+int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
+ u_char *buf)
+{
+ int ret_code;
+ *retlen = 0;
+ if (from < 0 || from > mtd->size || len > mtd->size - from)
+ return -EINVAL;
+ if (!len)
+ return 0;
+
+ /*
+ * In the absence of an error, drivers return a non-negative integer
+ * representing the maximum number of bitflips that were corrected on
+ * any one ecc region (if applicable; zero otherwise).
+ */
+ ret_code = mtd->_read(mtd, from, len, retlen, buf);
+ if (unlikely(ret_code < 0))
+ return ret_code;
+ if (mtd->ecc_strength == 0)
+ return 0; /* device lacks ecc */
+ return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
+}
+EXPORT_SYMBOL_GPL(mtd_read);
+
+int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
+ const u_char *buf)
+{
+ *retlen = 0;
+ if (to < 0 || to > mtd->size || len > mtd->size - to)
+ return -EINVAL;
+ if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
+ return -EROFS;
+ if (!len)
+ return 0;
+ return mtd->_write(mtd, to, len, retlen, buf);
+}
+EXPORT_SYMBOL_GPL(mtd_write);
+
+/*
+ * In blackbox flight recorder like scenarios we want to make successful writes
+ * in interrupt context. panic_write() is only intended to be called when its
+ * known the kernel is about to panic and we need the write to succeed. Since
+ * the kernel is not going to be running for much longer, this function can
+ * break locks and delay to ensure the write succeeds (but not sleep).
+ */
+int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
+ const u_char *buf)
+{
+ *retlen = 0;
+ if (!mtd->_panic_write)
+ return -EOPNOTSUPP;
+ if (to < 0 || to > mtd->size || len > mtd->size - to)
+ return -EINVAL;
+ if (!(mtd->flags & MTD_WRITEABLE))
+ return -EROFS;
+ if (!len)
+ return 0;
+ return mtd->_panic_write(mtd, to, len, retlen, buf);
+}
+EXPORT_SYMBOL_GPL(mtd_panic_write);
+
+int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
+{
+ int ret_code;
+ ops->retlen = ops->oobretlen = 0;
+ if (!mtd->_read_oob)
+ return -EOPNOTSUPP;
+ /*
+ * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
+ * similar to mtd->_read(), returning a non-negative integer
+ * representing max bitflips. In other cases, mtd->_read_oob() may
+ * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
+ */
+ ret_code = mtd->_read_oob(mtd, from, ops);
+ if (unlikely(ret_code < 0))
+ return ret_code;
+ if (mtd->ecc_strength == 0)
+ return 0; /* device lacks ecc */
+ return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
+}
+EXPORT_SYMBOL_GPL(mtd_read_oob);
+
+/*
+ * Method to access the protection register area, present in some flash
+ * devices. The user data is one time programmable but the factory data is read
+ * only.
+ */
+int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
+ struct otp_info *buf)
+{
+ if (!mtd->_get_fact_prot_info)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
+}
+EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
+
+int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ *retlen = 0;
+ if (!mtd->_read_fact_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
+}
+EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
+
+int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
+ struct otp_info *buf)
+{
+ if (!mtd->_get_user_prot_info)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return mtd->_get_user_prot_info(mtd, len, retlen, buf);
+}
+EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
+
+int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ *retlen = 0;
+ if (!mtd->_read_user_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
+}
+EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
+
+int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ int ret;
+
+ *retlen = 0;
+ if (!mtd->_write_user_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
+ if (ret)
+ return ret;
+
+ /*
+ * If no data could be written at all, we are out of memory and
+ * must return -ENOSPC.
+ */
+ return (*retlen) ? 0 : -ENOSPC;
+}
+EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
+
+int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
+{
+ if (!mtd->_lock_user_prot_reg)
+ return -EOPNOTSUPP;
+ if (!len)
+ return 0;
+ return mtd->_lock_user_prot_reg(mtd, from, len);
+}
+EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
+
+/* Chip-supported device locking */
+int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ if (!mtd->_lock)
+ return -EOPNOTSUPP;
+ if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
+ return -EINVAL;
+ if (!len)
+ return 0;
+ return mtd->_lock(mtd, ofs, len);
+}
+EXPORT_SYMBOL_GPL(mtd_lock);
+
+int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ if (!mtd->_unlock)
+ return -EOPNOTSUPP;
+ if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
+ return -EINVAL;
+ if (!len)
+ return 0;
+ return mtd->_unlock(mtd, ofs, len);
+}
+EXPORT_SYMBOL_GPL(mtd_unlock);
+
+int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ if (!mtd->_is_locked)
+ return -EOPNOTSUPP;
+ if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
+ return -EINVAL;
+ if (!len)
+ return 0;
+ return mtd->_is_locked(mtd, ofs, len);
+}
+EXPORT_SYMBOL_GPL(mtd_is_locked);
+
+int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
+{
+ if (ofs < 0 || ofs > mtd->size)
+ return -EINVAL;
+ if (!mtd->_block_isreserved)
+ return 0;
+ return mtd->_block_isreserved(mtd, ofs);
+}
+EXPORT_SYMBOL_GPL(mtd_block_isreserved);
+
+int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
+ if (ofs < 0 || ofs > mtd->size)
+ return -EINVAL;
+ if (!mtd->_block_isbad)
+ return 0;
+ return mtd->_block_isbad(mtd, ofs);
+}
+EXPORT_SYMBOL_GPL(mtd_block_isbad);
+
+int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+ if (!mtd->_block_markbad)
+ return -EOPNOTSUPP;
+ if (ofs < 0 || ofs > mtd->size)
+ return -EINVAL;
+ if (!(mtd->flags & MTD_WRITEABLE))
+ return -EROFS;
+ return mtd->_block_markbad(mtd, ofs);
+}
+EXPORT_SYMBOL_GPL(mtd_block_markbad);
+
+#ifndef __UBOOT__
+/*
+ * default_mtd_writev - the default writev method
+ * @mtd: mtd device description object pointer
+ * @vecs: the vectors to write
+ * @count: count of vectors in @vecs
+ * @to: the MTD device offset to write to
+ * @retlen: on exit contains the count of bytes written to the MTD device.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
+ unsigned long count, loff_t to, size_t *retlen)
+{
+ unsigned long i;
+ size_t totlen = 0, thislen;
+ int ret = 0;
+
+ for (i = 0; i < count; i++) {
+ if (!vecs[i].iov_len)
+ continue;
+ ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
+ vecs[i].iov_base);
+ totlen += thislen;
+ if (ret || thislen != vecs[i].iov_len)
+ break;
+ to += vecs[i].iov_len;
+ }
+ *retlen = totlen;
+ return ret;
+}
+
+/*
+ * mtd_writev - the vector-based MTD write method
+ * @mtd: mtd device description object pointer
+ * @vecs: the vectors to write
+ * @count: count of vectors in @vecs
+ * @to: the MTD device offset to write to
+ * @retlen: on exit contains the count of bytes written to the MTD device.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
+ unsigned long count, loff_t to, size_t *retlen)
+{
+ *retlen = 0;
+ if (!(mtd->flags & MTD_WRITEABLE))
+ return -EROFS;
+ if (!mtd->_writev)
+ return default_mtd_writev(mtd, vecs, count, to, retlen);
+ return mtd->_writev(mtd, vecs, count, to, retlen);
+}
+EXPORT_SYMBOL_GPL(mtd_writev);
+
+/**
+ * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
+ * @mtd: mtd device description object pointer
+ * @size: a pointer to the ideal or maximum size of the allocation, points
+ * to the actual allocation size on success.
+ *
+ * This routine attempts to allocate a contiguous kernel buffer up to
+ * the specified size, backing off the size of the request exponentially
+ * until the request succeeds or until the allocation size falls below
+ * the system page size. This attempts to make sure it does not adversely
+ * impact system performance, so when allocating more than one page, we
+ * ask the memory allocator to avoid re-trying, swapping, writing back
+ * or performing I/O.
+ *
+ * Note, this function also makes sure that the allocated buffer is aligned to
+ * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
+ *
+ * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
+ * to handle smaller (i.e. degraded) buffer allocations under low- or
+ * fragmented-memory situations where such reduced allocations, from a
+ * requested ideal, are allowed.
+ *
+ * Returns a pointer to the allocated buffer on success; otherwise, NULL.
+ */
+void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
+{
+ gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
+ __GFP_NORETRY | __GFP_NO_KSWAPD;
+ size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
+ void *kbuf;
+
+ *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
+
+ while (*size > min_alloc) {
+ kbuf = kmalloc(*size, flags);
+ if (kbuf)
+ return kbuf;
+
+ *size >>= 1;
+ *size = ALIGN(*size, mtd->writesize);
+ }
+
+ /*
+ * For the last resort allocation allow 'kmalloc()' to do all sorts of
+ * things (write-back, dropping caches, etc) by using GFP_KERNEL.
+ */
+ return kmalloc(*size, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
+#endif
+
+#ifdef CONFIG_PROC_FS
+
+/*====================================================================*/
+/* Support for /proc/mtd */
+
+static int mtd_proc_show(struct seq_file *m, void *v)
+{
+ struct mtd_info *mtd;
+
+ seq_puts(m, "dev: size erasesize name\n");
+ mutex_lock(&mtd_table_mutex);
+ mtd_for_each_device(mtd) {
+ seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
+ mtd->index, (unsigned long long)mtd->size,
+ mtd->erasesize, mtd->name);
+ }
+ mutex_unlock(&mtd_table_mutex);
+ return 0;
+}
+
+static int mtd_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, mtd_proc_show, NULL);
+}
+
+static const struct file_operations mtd_proc_ops = {
+ .open = mtd_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#endif /* CONFIG_PROC_FS */
+
+/*====================================================================*/
+/* Init code */
+
+#ifndef __UBOOT__
+static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
+{
+ int ret;
+
+ ret = bdi_init(bdi);
+ if (!ret)
+ ret = bdi_register(bdi, NULL, "%s", name);
+
+ if (ret)
+ bdi_destroy(bdi);
+
+ return ret;
+}
+
+static struct proc_dir_entry *proc_mtd;
+
+static int __init init_mtd(void)
+{
+ int ret;
+
+ ret = class_register(&mtd_class);
+ if (ret)
+ goto err_reg;
+
+ ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
+ if (ret)
+ goto err_bdi1;
+
+ ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
+ if (ret)
+ goto err_bdi2;
+
+ ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
+ if (ret)
+ goto err_bdi3;
+
+ proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
+
+ ret = init_mtdchar();
+ if (ret)
+ goto out_procfs;
+
+ return 0;
+
+out_procfs:
+ if (proc_mtd)
+ remove_proc_entry("mtd", NULL);
+err_bdi3:
+ bdi_destroy(&mtd_bdi_ro_mappable);
+err_bdi2:
+ bdi_destroy(&mtd_bdi_unmappable);
+err_bdi1:
+ class_unregister(&mtd_class);
+err_reg:
+ pr_err("Error registering mtd class or bdi: %d\n", ret);
+ return ret;
+}
+
+static void __exit cleanup_mtd(void)
+{
+ cleanup_mtdchar();
+ if (proc_mtd)
+ remove_proc_entry("mtd", NULL);
+ class_unregister(&mtd_class);
+ bdi_destroy(&mtd_bdi_unmappable);
+ bdi_destroy(&mtd_bdi_ro_mappable);
+ bdi_destroy(&mtd_bdi_rw_mappable);
+}
+
+module_init(init_mtd);
+module_exit(cleanup_mtd);
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("Core MTD registration and access routines");