+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);
+
+/**
+ * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
+ * @mtd: MTD device structure
+ * @section: ECC section. Depending on the layout you may have all the ECC
+ * bytes stored in a single contiguous section, or one section
+ * per ECC chunk (and sometime several sections for a single ECC
+ * ECC chunk)
+ * @oobecc: OOB region struct filled with the appropriate ECC position
+ * information
+ *
+ * This function returns ECC section information in the OOB area. If you want
+ * to get all the ECC bytes information, then you should call
+ * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
+ struct mtd_oob_region *oobecc)
+{
+ memset(oobecc, 0, sizeof(*oobecc));
+
+ if (!mtd || section < 0)
+ return -EINVAL;
+
+ if (!mtd->ooblayout || !mtd->ooblayout->ecc)
+ return -ENOTSUPP;
+
+ return mtd->ooblayout->ecc(mtd, section, oobecc);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
+
+/**
+ * mtd_ooblayout_free - Get the OOB region definition of a specific free
+ * section
+ * @mtd: MTD device structure
+ * @section: Free section you are interested in. Depending on the layout
+ * you may have all the free bytes stored in a single contiguous
+ * section, or one section per ECC chunk plus an extra section
+ * for the remaining bytes (or other funky layout).
+ * @oobfree: OOB region struct filled with the appropriate free position
+ * information
+ *
+ * This function returns free bytes position in the OOB area. If you want
+ * to get all the free bytes information, then you should call
+ * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_free(struct mtd_info *mtd, int section,
+ struct mtd_oob_region *oobfree)
+{
+ memset(oobfree, 0, sizeof(*oobfree));
+
+ if (!mtd || section < 0)
+ return -EINVAL;
+
+ if (!mtd->ooblayout || !mtd->ooblayout->free)
+ return -ENOTSUPP;
+
+ return mtd->ooblayout->free(mtd, section, oobfree);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
+
+/**
+ * mtd_ooblayout_find_region - Find the region attached to a specific byte
+ * @mtd: mtd info structure
+ * @byte: the byte we are searching for
+ * @sectionp: pointer where the section id will be stored
+ * @oobregion: used to retrieve the ECC position
+ * @iter: iterator function. Should be either mtd_ooblayout_free or
+ * mtd_ooblayout_ecc depending on the region type you're searching for
+ *
+ * This function returns the section id and oobregion information of a
+ * specific byte. For example, say you want to know where the 4th ECC byte is
+ * stored, you'll use:
+ *
+ * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
+ int *sectionp, struct mtd_oob_region *oobregion,
+ int (*iter)(struct mtd_info *,
+ int section,
+ struct mtd_oob_region *oobregion))
+{
+ int pos = 0, ret, section = 0;
+
+ memset(oobregion, 0, sizeof(*oobregion));
+
+ while (1) {
+ ret = iter(mtd, section, oobregion);
+ if (ret)
+ return ret;
+
+ if (pos + oobregion->length > byte)
+ break;
+
+ pos += oobregion->length;
+ section++;
+ }
+
+ /*
+ * Adjust region info to make it start at the beginning at the
+ * 'start' ECC byte.
+ */
+ oobregion->offset += byte - pos;
+ oobregion->length -= byte - pos;
+ *sectionp = section;
+
+ return 0;
+}
+
+/**
+ * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
+ * ECC byte
+ * @mtd: mtd info structure
+ * @eccbyte: the byte we are searching for
+ * @sectionp: pointer where the section id will be stored
+ * @oobregion: OOB region information
+ *
+ * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
+ * byte.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
+ int *section,
+ struct mtd_oob_region *oobregion)
+{
+ return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
+ mtd_ooblayout_ecc);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
+
+/**
+ * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
+ * @mtd: mtd info structure
+ * @buf: destination buffer to store OOB bytes
+ * @oobbuf: OOB buffer
+ * @start: first byte to retrieve
+ * @nbytes: number of bytes to retrieve
+ * @iter: section iterator
+ *
+ * Extract bytes attached to a specific category (ECC or free)
+ * from the OOB buffer and copy them into buf.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
+ const u8 *oobbuf, int start, int nbytes,
+ int (*iter)(struct mtd_info *,
+ int section,
+ struct mtd_oob_region *oobregion))
+{
+ struct mtd_oob_region oobregion;
+ int section, ret;
+
+ ret = mtd_ooblayout_find_region(mtd, start, §ion,
+ &oobregion, iter);
+
+ while (!ret) {
+ int cnt;
+
+ cnt = min_t(int, nbytes, oobregion.length);
+ memcpy(buf, oobbuf + oobregion.offset, cnt);
+ buf += cnt;
+ nbytes -= cnt;
+
+ if (!nbytes)
+ break;
+
+ ret = iter(mtd, ++section, &oobregion);
+ }
+
+ return ret;
+}
+
+/**
+ * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
+ * @mtd: mtd info structure
+ * @buf: source buffer to get OOB bytes from
+ * @oobbuf: OOB buffer
+ * @start: first OOB byte to set
+ * @nbytes: number of OOB bytes to set
+ * @iter: section iterator
+ *
+ * Fill the OOB buffer with data provided in buf. The category (ECC or free)
+ * is selected by passing the appropriate iterator.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
+ u8 *oobbuf, int start, int nbytes,
+ int (*iter)(struct mtd_info *,
+ int section,
+ struct mtd_oob_region *oobregion))
+{
+ struct mtd_oob_region oobregion;
+ int section, ret;
+
+ ret = mtd_ooblayout_find_region(mtd, start, §ion,
+ &oobregion, iter);
+
+ while (!ret) {
+ int cnt;
+
+ cnt = min_t(int, nbytes, oobregion.length);
+ memcpy(oobbuf + oobregion.offset, buf, cnt);
+ buf += cnt;
+ nbytes -= cnt;
+
+ if (!nbytes)
+ break;
+
+ ret = iter(mtd, ++section, &oobregion);
+ }
+
+ return ret;
+}
+
+/**
+ * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
+ * @mtd: mtd info structure
+ * @iter: category iterator
+ *
+ * Count the number of bytes in a given category.
+ *
+ * Returns a positive value on success, a negative error code otherwise.
+ */
+static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
+ int (*iter)(struct mtd_info *,
+ int section,
+ struct mtd_oob_region *oobregion))
+{
+ struct mtd_oob_region oobregion;
+ int section = 0, ret, nbytes = 0;
+
+ while (1) {
+ ret = iter(mtd, section++, &oobregion);
+ if (ret) {
+ if (ret == -ERANGE)
+ ret = nbytes;
+ break;
+ }
+
+ nbytes += oobregion.length;
+ }
+
+ return ret;
+}
+
+/**
+ * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
+ * @mtd: mtd info structure
+ * @eccbuf: destination buffer to store ECC bytes
+ * @oobbuf: OOB buffer
+ * @start: first ECC byte to retrieve
+ * @nbytes: number of ECC bytes to retrieve
+ *
+ * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
+ const u8 *oobbuf, int start, int nbytes)
+{
+ return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
+ mtd_ooblayout_ecc);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
+
+/**
+ * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
+ * @mtd: mtd info structure
+ * @eccbuf: source buffer to get ECC bytes from
+ * @oobbuf: OOB buffer
+ * @start: first ECC byte to set
+ * @nbytes: number of ECC bytes to set
+ *
+ * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
+ u8 *oobbuf, int start, int nbytes)
+{
+ return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
+ mtd_ooblayout_ecc);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
+
+/**
+ * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
+ * @mtd: mtd info structure
+ * @databuf: destination buffer to store ECC bytes
+ * @oobbuf: OOB buffer
+ * @start: first ECC byte to retrieve
+ * @nbytes: number of ECC bytes to retrieve
+ *
+ * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
+ const u8 *oobbuf, int start, int nbytes)
+{
+ return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
+ mtd_ooblayout_free);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
+
+/**
+ * mtd_ooblayout_get_eccbytes - set data bytes into the oob buffer
+ * @mtd: mtd info structure
+ * @eccbuf: source buffer to get data bytes from
+ * @oobbuf: OOB buffer
+ * @start: first ECC byte to set
+ * @nbytes: number of ECC bytes to set
+ *
+ * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
+ u8 *oobbuf, int start, int nbytes)
+{
+ return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
+ mtd_ooblayout_free);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
+
+/**
+ * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
+ * @mtd: mtd info structure
+ *
+ * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
+{
+ return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
+
+/**
+ * mtd_ooblayout_count_freebytes - count the number of ECC bytes in OOB
+ * @mtd: mtd info structure
+ *
+ * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
+ *
+ * Returns zero on success, a negative error code otherwise.
+ */
+int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
+{
+ return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
+}
+EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
+
+/*
+ * 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");