--- /dev/null
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ * Copyright (c) Nokia Corporation, 2007
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём),
+ * Frank Haverkamp
+ */
+
+/*
+ * This file includes UBI initialization and building of UBI devices.
+ *
+ * When UBI is initialized, it attaches all the MTD devices specified as the
+ * module load parameters or the kernel boot parameters. If MTD devices were
+ * specified, UBI does not attach any MTD device, but it is possible to do
+ * later using the "UBI control device".
+ *
+ * At the moment we only attach UBI devices by scanning, which will become a
+ * bottleneck when flashes reach certain large size. Then one may improve UBI
+ * and add other methods, although it does not seem to be easy to do.
+ */
+
+#ifdef UBI_LINUX
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/stringify.h>
+#include <linux/stat.h>
+#include <linux/miscdevice.h>
+#include <linux/log2.h>
+#include <linux/kthread.h>
+#endif
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+/* Maximum length of the 'mtd=' parameter */
+#define MTD_PARAM_LEN_MAX 64
+
+/**
+ * struct mtd_dev_param - MTD device parameter description data structure.
+ * @name: MTD device name or number string
+ * @vid_hdr_offs: VID header offset
+ */
+struct mtd_dev_param
+{
+ char name[MTD_PARAM_LEN_MAX];
+ int vid_hdr_offs;
+};
+
+/* Numbers of elements set in the @mtd_dev_param array */
+static int mtd_devs = 0;
+
+/* MTD devices specification parameters */
+static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
+
+/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
+struct class *ubi_class;
+
+#ifdef UBI_LINUX
+/* Slab cache for wear-leveling entries */
+struct kmem_cache *ubi_wl_entry_slab;
+
+/* UBI control character device */
+static struct miscdevice ubi_ctrl_cdev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "ubi_ctrl",
+ .fops = &ubi_ctrl_cdev_operations,
+};
+#endif
+
+/* All UBI devices in system */
+struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
+
+#ifdef UBI_LINUX
+/* Serializes UBI devices creations and removals */
+DEFINE_MUTEX(ubi_devices_mutex);
+
+/* Protects @ubi_devices and @ubi->ref_count */
+static DEFINE_SPINLOCK(ubi_devices_lock);
+
+/* "Show" method for files in '/<sysfs>/class/ubi/' */
+static ssize_t ubi_version_show(struct class *class, char *buf)
+{
+ return sprintf(buf, "%d\n", UBI_VERSION);
+}
+
+/* UBI version attribute ('/<sysfs>/class/ubi/version') */
+static struct class_attribute ubi_version =
+ __ATTR(version, S_IRUGO, ubi_version_show, NULL);
+
+static ssize_t dev_attribute_show(struct device *dev,
+ struct device_attribute *attr, char *buf);
+
+/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
+static struct device_attribute dev_eraseblock_size =
+ __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_avail_eraseblocks =
+ __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_total_eraseblocks =
+ __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_volumes_count =
+ __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_max_ec =
+ __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_reserved_for_bad =
+ __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_bad_peb_count =
+ __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_max_vol_count =
+ __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_min_io_size =
+ __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_bgt_enabled =
+ __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_mtd_num =
+ __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
+#endif
+
+/**
+ * ubi_get_device - get UBI device.
+ * @ubi_num: UBI device number
+ *
+ * This function returns UBI device description object for UBI device number
+ * @ubi_num, or %NULL if the device does not exist. This function increases the
+ * device reference count to prevent removal of the device. In other words, the
+ * device cannot be removed if its reference count is not zero.
+ */
+struct ubi_device *ubi_get_device(int ubi_num)
+{
+ struct ubi_device *ubi;
+
+ spin_lock(&ubi_devices_lock);
+ ubi = ubi_devices[ubi_num];
+ if (ubi) {
+ ubi_assert(ubi->ref_count >= 0);
+ ubi->ref_count += 1;
+ get_device(&ubi->dev);
+ }
+ spin_unlock(&ubi_devices_lock);
+
+ return ubi;
+}
+
+/**
+ * ubi_put_device - drop an UBI device reference.
+ * @ubi: UBI device description object
+ */
+void ubi_put_device(struct ubi_device *ubi)
+{
+ spin_lock(&ubi_devices_lock);
+ ubi->ref_count -= 1;
+ put_device(&ubi->dev);
+ spin_unlock(&ubi_devices_lock);
+}
+
+/**
+ * ubi_get_by_major - get UBI device description object by character device
+ * major number.
+ * @major: major number
+ *
+ * This function is similar to 'ubi_get_device()', but it searches the device
+ * by its major number.
+ */
+struct ubi_device *ubi_get_by_major(int major)
+{
+ int i;
+ struct ubi_device *ubi;
+
+ spin_lock(&ubi_devices_lock);
+ for (i = 0; i < UBI_MAX_DEVICES; i++) {
+ ubi = ubi_devices[i];
+ if (ubi && MAJOR(ubi->cdev.dev) == major) {
+ ubi_assert(ubi->ref_count >= 0);
+ ubi->ref_count += 1;
+ get_device(&ubi->dev);
+ spin_unlock(&ubi_devices_lock);
+ return ubi;
+ }
+ }
+ spin_unlock(&ubi_devices_lock);
+
+ return NULL;
+}
+
+/**
+ * ubi_major2num - get UBI device number by character device major number.
+ * @major: major number
+ *
+ * This function searches UBI device number object by its major number. If UBI
+ * device was not found, this function returns -ENODEV, otherwise the UBI device
+ * number is returned.
+ */
+int ubi_major2num(int major)
+{
+ int i, ubi_num = -ENODEV;
+
+ spin_lock(&ubi_devices_lock);
+ for (i = 0; i < UBI_MAX_DEVICES; i++) {
+ struct ubi_device *ubi = ubi_devices[i];
+
+ if (ubi && MAJOR(ubi->cdev.dev) == major) {
+ ubi_num = ubi->ubi_num;
+ break;
+ }
+ }
+ spin_unlock(&ubi_devices_lock);
+
+ return ubi_num;
+}
+
+#ifdef UBI_LINUX
+/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
+static ssize_t dev_attribute_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t ret;
+ struct ubi_device *ubi;
+
+ /*
+ * The below code looks weird, but it actually makes sense. We get the
+ * UBI device reference from the contained 'struct ubi_device'. But it
+ * is unclear if the device was removed or not yet. Indeed, if the
+ * device was removed before we increased its reference count,
+ * 'ubi_get_device()' will return -ENODEV and we fail.
+ *
+ * Remember, 'struct ubi_device' is freed in the release function, so
+ * we still can use 'ubi->ubi_num'.
+ */
+ ubi = container_of(dev, struct ubi_device, dev);
+ ubi = ubi_get_device(ubi->ubi_num);
+ if (!ubi)
+ return -ENODEV;
+
+ if (attr == &dev_eraseblock_size)
+ ret = sprintf(buf, "%d\n", ubi->leb_size);
+ else if (attr == &dev_avail_eraseblocks)
+ ret = sprintf(buf, "%d\n", ubi->avail_pebs);
+ else if (attr == &dev_total_eraseblocks)
+ ret = sprintf(buf, "%d\n", ubi->good_peb_count);
+ else if (attr == &dev_volumes_count)
+ ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
+ else if (attr == &dev_max_ec)
+ ret = sprintf(buf, "%d\n", ubi->max_ec);
+ else if (attr == &dev_reserved_for_bad)
+ ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
+ else if (attr == &dev_bad_peb_count)
+ ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
+ else if (attr == &dev_max_vol_count)
+ ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
+ else if (attr == &dev_min_io_size)
+ ret = sprintf(buf, "%d\n", ubi->min_io_size);
+ else if (attr == &dev_bgt_enabled)
+ ret = sprintf(buf, "%d\n", ubi->thread_enabled);
+ else if (attr == &dev_mtd_num)
+ ret = sprintf(buf, "%d\n", ubi->mtd->index);
+ else
+ ret = -EINVAL;
+
+ ubi_put_device(ubi);
+ return ret;
+}
+
+/* Fake "release" method for UBI devices */
+static void dev_release(struct device *dev) { }
+
+/**
+ * ubi_sysfs_init - initialize sysfs for an UBI device.
+ * @ubi: UBI device description object
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int ubi_sysfs_init(struct ubi_device *ubi)
+{
+ int err;
+
+ ubi->dev.release = dev_release;
+ ubi->dev.devt = ubi->cdev.dev;
+ ubi->dev.class = ubi_class;
+ sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
+ err = device_register(&ubi->dev);
+ if (err)
+ return err;
+
+ err = device_create_file(&ubi->dev, &dev_eraseblock_size);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_volumes_count);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_max_ec);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_bad_peb_count);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_max_vol_count);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_min_io_size);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_bgt_enabled);
+ if (err)
+ return err;
+ err = device_create_file(&ubi->dev, &dev_mtd_num);
+ return err;
+}
+
+/**
+ * ubi_sysfs_close - close sysfs for an UBI device.
+ * @ubi: UBI device description object
+ */
+static void ubi_sysfs_close(struct ubi_device *ubi)
+{
+ device_remove_file(&ubi->dev, &dev_mtd_num);
+ device_remove_file(&ubi->dev, &dev_bgt_enabled);
+ device_remove_file(&ubi->dev, &dev_min_io_size);
+ device_remove_file(&ubi->dev, &dev_max_vol_count);
+ device_remove_file(&ubi->dev, &dev_bad_peb_count);
+ device_remove_file(&ubi->dev, &dev_reserved_for_bad);
+ device_remove_file(&ubi->dev, &dev_max_ec);
+ device_remove_file(&ubi->dev, &dev_volumes_count);
+ device_remove_file(&ubi->dev, &dev_total_eraseblocks);
+ device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
+ device_remove_file(&ubi->dev, &dev_eraseblock_size);
+ device_unregister(&ubi->dev);
+}
+#endif
+
+/**
+ * kill_volumes - destroy all volumes.
+ * @ubi: UBI device description object
+ */
+static void kill_volumes(struct ubi_device *ubi)
+{
+ int i;
+
+ for (i = 0; i < ubi->vtbl_slots; i++)
+ if (ubi->volumes[i])
+ ubi_free_volume(ubi, ubi->volumes[i]);
+}
+
+/**
+ * uif_init - initialize user interfaces for an UBI device.
+ * @ubi: UBI device description object
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int uif_init(struct ubi_device *ubi)
+{
+ int i, err;
+#ifdef UBI_LINUX
+ dev_t dev;
+#endif
+
+ sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
+
+ /*
+ * Major numbers for the UBI character devices are allocated
+ * dynamically. Major numbers of volume character devices are
+ * equivalent to ones of the corresponding UBI character device. Minor
+ * numbers of UBI character devices are 0, while minor numbers of
+ * volume character devices start from 1. Thus, we allocate one major
+ * number and ubi->vtbl_slots + 1 minor numbers.
+ */
+ err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
+ if (err) {
+ ubi_err("cannot register UBI character devices");
+ return err;
+ }
+
+ ubi_assert(MINOR(dev) == 0);
+ cdev_init(&ubi->cdev, &ubi_cdev_operations);
+ dbg_msg("%s major is %u", ubi->ubi_name, MAJOR(dev));
+ ubi->cdev.owner = THIS_MODULE;
+
+ err = cdev_add(&ubi->cdev, dev, 1);
+ if (err) {
+ ubi_err("cannot add character device");
+ goto out_unreg;
+ }
+
+ err = ubi_sysfs_init(ubi);
+ if (err)
+ goto out_sysfs;
+
+ for (i = 0; i < ubi->vtbl_slots; i++)
+ if (ubi->volumes[i]) {
+ err = ubi_add_volume(ubi, ubi->volumes[i]);
+ if (err) {
+ ubi_err("cannot add volume %d", i);
+ goto out_volumes;
+ }
+ }
+
+ return 0;
+
+out_volumes:
+ kill_volumes(ubi);
+out_sysfs:
+ ubi_sysfs_close(ubi);
+ cdev_del(&ubi->cdev);
+out_unreg:
+ unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
+ ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
+ return err;
+}
+
+/**
+ * uif_close - close user interfaces for an UBI device.
+ * @ubi: UBI device description object
+ */
+static void uif_close(struct ubi_device *ubi)
+{
+ kill_volumes(ubi);
+ ubi_sysfs_close(ubi);
+ cdev_del(&ubi->cdev);
+ unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
+}
+
+/**
+ * attach_by_scanning - attach an MTD device using scanning method.
+ * @ubi: UBI device descriptor
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ *
+ * Note, currently this is the only method to attach UBI devices. Hopefully in
+ * the future we'll have more scalable attaching methods and avoid full media
+ * scanning. But even in this case scanning will be needed as a fall-back
+ * attaching method if there are some on-flash table corruptions.
+ */
+static int attach_by_scanning(struct ubi_device *ubi)
+{
+ int err;
+ struct ubi_scan_info *si;
+
+ si = ubi_scan(ubi);
+ if (IS_ERR(si))
+ return PTR_ERR(si);
+
+ ubi->bad_peb_count = si->bad_peb_count;
+ ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
+ ubi->max_ec = si->max_ec;
+ ubi->mean_ec = si->mean_ec;
+
+ err = ubi_read_volume_table(ubi, si);
+ if (err)
+ goto out_si;
+
+ err = ubi_wl_init_scan(ubi, si);
+ if (err)
+ goto out_vtbl;
+
+ err = ubi_eba_init_scan(ubi, si);
+ if (err)
+ goto out_wl;
+
+ ubi_scan_destroy_si(si);
+ return 0;
+
+out_wl:
+ ubi_wl_close(ubi);
+out_vtbl:
+ vfree(ubi->vtbl);
+out_si:
+ ubi_scan_destroy_si(si);
+ return err;
+}
+
+/**
+ * io_init - initialize I/O unit for a given UBI device.
+ * @ubi: UBI device description object
+ *
+ * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
+ * assumed:
+ * o EC header is always at offset zero - this cannot be changed;
+ * o VID header starts just after the EC header at the closest address
+ * aligned to @io->hdrs_min_io_size;
+ * o data starts just after the VID header at the closest address aligned to
+ * @io->min_io_size
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int io_init(struct ubi_device *ubi)
+{
+ if (ubi->mtd->numeraseregions != 0) {
+ /*
+ * Some flashes have several erase regions. Different regions
+ * may have different eraseblock size and other
+ * characteristics. It looks like mostly multi-region flashes
+ * have one "main" region and one or more small regions to
+ * store boot loader code or boot parameters or whatever. I
+ * guess we should just pick the largest region. But this is
+ * not implemented.
+ */
+ ubi_err("multiple regions, not implemented");
+ return -EINVAL;
+ }
+
+ if (ubi->vid_hdr_offset < 0)
+ return -EINVAL;
+
+ /*
+ * Note, in this implementation we support MTD devices with 0x7FFFFFFF
+ * physical eraseblocks maximum.
+ */
+
+ ubi->peb_size = ubi->mtd->erasesize;
+ ubi->peb_count = ubi->mtd->size / ubi->mtd->erasesize;
+ ubi->flash_size = ubi->mtd->size;
+
+ if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
+ ubi->bad_allowed = 1;
+
+ ubi->min_io_size = ubi->mtd->writesize;
+ ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
+
+ /*
+ * Make sure minimal I/O unit is power of 2. Note, there is no
+ * fundamental reason for this assumption. It is just an optimization
+ * which allows us to avoid costly division operations.
+ */
+ if (!is_power_of_2(ubi->min_io_size)) {
+ ubi_err("min. I/O unit (%d) is not power of 2",
+ ubi->min_io_size);
+ return -EINVAL;
+ }
+
+ ubi_assert(ubi->hdrs_min_io_size > 0);
+ ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
+ ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
+
+ /* Calculate default aligned sizes of EC and VID headers */
+ ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
+ ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
+
+ dbg_msg("min_io_size %d", ubi->min_io_size);
+ dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
+ dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
+ dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
+
+ if (ubi->vid_hdr_offset == 0)
+ /* Default offset */
+ ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
+ ubi->ec_hdr_alsize;
+ else {
+ ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
+ ~(ubi->hdrs_min_io_size - 1);
+ ubi->vid_hdr_shift = ubi->vid_hdr_offset -
+ ubi->vid_hdr_aloffset;
+ }
+
+ /* Similar for the data offset */
+ ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
+ ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
+
+ dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
+ dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
+ dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
+ dbg_msg("leb_start %d", ubi->leb_start);
+
+ /* The shift must be aligned to 32-bit boundary */
+ if (ubi->vid_hdr_shift % 4) {
+ ubi_err("unaligned VID header shift %d",
+ ubi->vid_hdr_shift);
+ return -EINVAL;
+ }
+
+ /* Check sanity */
+ if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
+ ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
+ ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
+ ubi->leb_start & (ubi->min_io_size - 1)) {
+ ubi_err("bad VID header (%d) or data offsets (%d)",
+ ubi->vid_hdr_offset, ubi->leb_start);
+ return -EINVAL;
+ }
+
+ /*
+ * It may happen that EC and VID headers are situated in one minimal
+ * I/O unit. In this case we can only accept this UBI image in
+ * read-only mode.
+ */
+ if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
+ ubi_warn("EC and VID headers are in the same minimal I/O unit, "
+ "switch to read-only mode");
+ ubi->ro_mode = 1;
+ }
+
+ ubi->leb_size = ubi->peb_size - ubi->leb_start;
+
+ if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
+ ubi_msg("MTD device %d is write-protected, attach in "
+ "read-only mode", ubi->mtd->index);
+ ubi->ro_mode = 1;
+ }
+
+ ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
+ ubi->peb_size, ubi->peb_size >> 10);
+ ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
+ ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
+ if (ubi->hdrs_min_io_size != ubi->min_io_size)
+ ubi_msg("sub-page size: %d",
+ ubi->hdrs_min_io_size);
+ ubi_msg("VID header offset: %d (aligned %d)",
+ ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
+ ubi_msg("data offset: %d", ubi->leb_start);
+
+ /*
+ * Note, ideally, we have to initialize ubi->bad_peb_count here. But
+ * unfortunately, MTD does not provide this information. We should loop
+ * over all physical eraseblocks and invoke mtd->block_is_bad() for
+ * each physical eraseblock. So, we skip ubi->bad_peb_count
+ * uninitialized and initialize it after scanning.
+ */
+
+ return 0;
+}
+
+/**
+ * autoresize - re-size the volume which has the "auto-resize" flag set.
+ * @ubi: UBI device description object
+ * @vol_id: ID of the volume to re-size
+ *
+ * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
+ * the volume table to the largest possible size. See comments in ubi-header.h
+ * for more description of the flag. Returns zero in case of success and a
+ * negative error code in case of failure.
+ */
+static int autoresize(struct ubi_device *ubi, int vol_id)
+{
+ struct ubi_volume_desc desc;
+ struct ubi_volume *vol = ubi->volumes[vol_id];
+ int err, old_reserved_pebs = vol->reserved_pebs;
+
+ /*
+ * Clear the auto-resize flag in the volume in-memory copy of the
+ * volume table, and 'ubi_resize_volume()' will propogate this change
+ * to the flash.
+ */
+ ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
+
+ if (ubi->avail_pebs == 0) {
+ struct ubi_vtbl_record vtbl_rec;
+
+ /*
+ * No avalilable PEBs to re-size the volume, clear the flag on
+ * flash and exit.
+ */
+ memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
+ sizeof(struct ubi_vtbl_record));
+ err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+ if (err)
+ ubi_err("cannot clean auto-resize flag for volume %d",
+ vol_id);
+ } else {
+ desc.vol = vol;
+ err = ubi_resize_volume(&desc,
+ old_reserved_pebs + ubi->avail_pebs);
+ if (err)
+ ubi_err("cannot auto-resize volume %d", vol_id);
+ }
+
+ if (err)
+ return err;
+
+ ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
+ vol->name, old_reserved_pebs, vol->reserved_pebs);
+ return 0;
+}
+
+/**
+ * ubi_attach_mtd_dev - attach an MTD device.
+ * @mtd_dev: MTD device description object
+ * @ubi_num: number to assign to the new UBI device
+ * @vid_hdr_offset: VID header offset
+ *
+ * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
+ * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
+ * which case this function finds a vacant device nubert and assings it
+ * automatically. Returns the new UBI device number in case of success and a
+ * negative error code in case of failure.
+ *
+ * Note, the invocations of this function has to be serialized by the
+ * @ubi_devices_mutex.
+ */
+int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
+{
+ struct ubi_device *ubi;
+ int i, err;
+
+ /*
+ * Check if we already have the same MTD device attached.
+ *
+ * Note, this function assumes that UBI devices creations and deletions
+ * are serialized, so it does not take the &ubi_devices_lock.
+ */
+ for (i = 0; i < UBI_MAX_DEVICES; i++) {
+ ubi = ubi_devices[i];
+ if (ubi && mtd->index == ubi->mtd->index) {
+ dbg_err("mtd%d is already attached to ubi%d",
+ mtd->index, i);
+ return -EEXIST;
+ }
+ }
+
+ /*
+ * Make sure this MTD device is not emulated on top of an UBI volume
+ * already. Well, generally this recursion works fine, but there are
+ * different problems like the UBI module takes a reference to itself
+ * by attaching (and thus, opening) the emulated MTD device. This
+ * results in inability to unload the module. And in general it makes
+ * no sense to attach emulated MTD devices, so we prohibit this.
+ */
+ if (mtd->type == MTD_UBIVOLUME) {
+ ubi_err("refuse attaching mtd%d - it is already emulated on "
+ "top of UBI", mtd->index);
+ return -EINVAL;
+ }
+
+ if (ubi_num == UBI_DEV_NUM_AUTO) {
+ /* Search for an empty slot in the @ubi_devices array */
+ for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
+ if (!ubi_devices[ubi_num])
+ break;
+ if (ubi_num == UBI_MAX_DEVICES) {
+ dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES);
+ return -ENFILE;
+ }
+ } else {
+ if (ubi_num >= UBI_MAX_DEVICES)
+ return -EINVAL;
+
+ /* Make sure ubi_num is not busy */
+ if (ubi_devices[ubi_num]) {
+ dbg_err("ubi%d already exists", ubi_num);
+ return -EEXIST;
+ }
+ }
+
+ ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
+ if (!ubi)
+ return -ENOMEM;
+
+ ubi->mtd = mtd;
+ ubi->ubi_num = ubi_num;
+ ubi->vid_hdr_offset = vid_hdr_offset;
+ ubi->autoresize_vol_id = -1;
+
+ mutex_init(&ubi->buf_mutex);
+ mutex_init(&ubi->ckvol_mutex);
+ mutex_init(&ubi->volumes_mutex);
+ spin_lock_init(&ubi->volumes_lock);
+
+ ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
+
+ err = io_init(ubi);
+ if (err)
+ goto out_free;
+
+ ubi->peb_buf1 = vmalloc(ubi->peb_size);
+ if (!ubi->peb_buf1)
+ goto out_free;
+
+ ubi->peb_buf2 = vmalloc(ubi->peb_size);
+ if (!ubi->peb_buf2)
+ goto out_free;
+
+#ifdef CONFIG_MTD_UBI_DEBUG
+ mutex_init(&ubi->dbg_buf_mutex);
+ ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
+ if (!ubi->dbg_peb_buf)
+ goto out_free;
+#endif
+
+ err = attach_by_scanning(ubi);
+ if (err) {
+ dbg_err("failed to attach by scanning, error %d", err);
+ goto out_free;
+ }
+
+ if (ubi->autoresize_vol_id != -1) {
+ err = autoresize(ubi, ubi->autoresize_vol_id);
+ if (err)
+ goto out_detach;
+ }
+
+ err = uif_init(ubi);
+ if (err)
+ goto out_detach;
+
+ ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
+ if (IS_ERR(ubi->bgt_thread)) {
+ err = PTR_ERR(ubi->bgt_thread);
+ ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
+ err);
+ goto out_uif;
+ }
+
+ ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
+ ubi_msg("MTD device name: \"%s\"", mtd->name);
+ ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
+ ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
+ ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
+ ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
+ ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
+ ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
+ ubi_msg("number of user volumes: %d",
+ ubi->vol_count - UBI_INT_VOL_COUNT);
+ ubi_msg("available PEBs: %d", ubi->avail_pebs);
+ ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
+ ubi_msg("number of PEBs reserved for bad PEB handling: %d",
+ ubi->beb_rsvd_pebs);
+ ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
+
+ /* Enable the background thread */
+ if (!DBG_DISABLE_BGT) {
+ ubi->thread_enabled = 1;
+ wake_up_process(ubi->bgt_thread);
+ }
+
+ ubi_devices[ubi_num] = ubi;
+ return ubi_num;
+
+out_uif:
+ uif_close(ubi);
+out_detach:
+ ubi_eba_close(ubi);
+ ubi_wl_close(ubi);
+ vfree(ubi->vtbl);
+out_free:
+ vfree(ubi->peb_buf1);
+ vfree(ubi->peb_buf2);
+#ifdef CONFIG_MTD_UBI_DEBUG
+ vfree(ubi->dbg_peb_buf);
+#endif
+ kfree(ubi);
+ return err;
+}
+
+/**
+ * ubi_detach_mtd_dev - detach an MTD device.
+ * @ubi_num: UBI device number to detach from
+ * @anyway: detach MTD even if device reference count is not zero
+ *
+ * This function destroys an UBI device number @ubi_num and detaches the
+ * underlying MTD device. Returns zero in case of success and %-EBUSY if the
+ * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
+ * exist.
+ *
+ * Note, the invocations of this function has to be serialized by the
+ * @ubi_devices_mutex.
+ */
+int ubi_detach_mtd_dev(int ubi_num, int anyway)
+{
+ struct ubi_device *ubi;
+
+ if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+ return -EINVAL;
+
+ spin_lock(&ubi_devices_lock);
+ ubi = ubi_devices[ubi_num];
+ if (!ubi) {
+ spin_unlock(&ubi_devices_lock);
+ return -EINVAL;
+ }
+
+ if (ubi->ref_count) {
+ if (!anyway) {
+ spin_unlock(&ubi_devices_lock);
+ return -EBUSY;
+ }
+ /* This may only happen if there is a bug */
+ ubi_err("%s reference count %d, destroy anyway",
+ ubi->ubi_name, ubi->ref_count);
+ }
+ ubi_devices[ubi_num] = NULL;
+ spin_unlock(&ubi_devices_lock);
+
+ ubi_assert(ubi_num == ubi->ubi_num);
+ dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
+
+ /*
+ * Before freeing anything, we have to stop the background thread to
+ * prevent it from doing anything on this device while we are freeing.
+ */
+ if (ubi->bgt_thread)
+ kthread_stop(ubi->bgt_thread);
+
+ uif_close(ubi);
+ ubi_eba_close(ubi);
+ ubi_wl_close(ubi);
+ vfree(ubi->vtbl);
+ put_mtd_device(ubi->mtd);
+ vfree(ubi->peb_buf1);
+ vfree(ubi->peb_buf2);
+#ifdef CONFIG_MTD_UBI_DEBUG
+ vfree(ubi->dbg_peb_buf);
+#endif
+ ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
+ kfree(ubi);
+ return 0;
+}
+
+/**
+ * find_mtd_device - open an MTD device by its name or number.
+ * @mtd_dev: name or number of the device
+ *
+ * This function tries to open and MTD device described by @mtd_dev string,
+ * which is first treated as an ASCII number, and if it is not true, it is
+ * treated as MTD device name. Returns MTD device description object in case of
+ * success and a negative error code in case of failure.
+ */
+static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
+{
+ struct mtd_info *mtd;
+ int mtd_num;
+ char *endp;
+
+ mtd_num = simple_strtoul(mtd_dev, &endp, 0);
+ if (*endp != '\0' || mtd_dev == endp) {
+ /*
+ * This does not look like an ASCII integer, probably this is
+ * MTD device name.
+ */
+ mtd = get_mtd_device_nm(mtd_dev);
+ } else
+ mtd = get_mtd_device(NULL, mtd_num);
+
+ return mtd;
+}
+
+int __init ubi_init(void)
+{
+ int err, i, k;
+
+ /* Ensure that EC and VID headers have correct size */
+ BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
+ BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
+
+ if (mtd_devs > UBI_MAX_DEVICES) {
+ ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
+ return -EINVAL;
+ }
+
+ /* Create base sysfs directory and sysfs files */
+ ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
+ if (IS_ERR(ubi_class)) {
+ err = PTR_ERR(ubi_class);
+ ubi_err("cannot create UBI class");
+ goto out;
+ }
+
+ err = class_create_file(ubi_class, &ubi_version);
+ if (err) {
+ ubi_err("cannot create sysfs file");
+ goto out_class;
+ }
+
+ err = misc_register(&ubi_ctrl_cdev);
+ if (err) {
+ ubi_err("cannot register device");
+ goto out_version;
+ }
+
+#ifdef UBI_LINUX
+ ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
+ sizeof(struct ubi_wl_entry),
+ 0, 0, NULL);
+ if (!ubi_wl_entry_slab)
+ goto out_dev_unreg;
+#endif
+
+ /* Attach MTD devices */
+ for (i = 0; i < mtd_devs; i++) {
+ struct mtd_dev_param *p = &mtd_dev_param[i];
+ struct mtd_info *mtd;
+
+ cond_resched();
+
+ mtd = open_mtd_device(p->name);
+ if (IS_ERR(mtd)) {
+ err = PTR_ERR(mtd);
+ goto out_detach;
+ }
+
+ mutex_lock(&ubi_devices_mutex);
+ err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
+ p->vid_hdr_offs);
+ mutex_unlock(&ubi_devices_mutex);
+ if (err < 0) {
+ put_mtd_device(mtd);
+ ubi_err("cannot attach mtd%d", mtd->index);
+ goto out_detach;
+ }
+ }
+
+ return 0;
+
+out_detach:
+ for (k = 0; k < i; k++)
+ if (ubi_devices[k]) {
+ mutex_lock(&ubi_devices_mutex);
+ ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
+ mutex_unlock(&ubi_devices_mutex);
+ }
+#ifdef UBI_LINUX
+ kmem_cache_destroy(ubi_wl_entry_slab);
+out_dev_unreg:
+#endif
+ misc_deregister(&ubi_ctrl_cdev);
+out_version:
+ class_remove_file(ubi_class, &ubi_version);
+out_class:
+ class_destroy(ubi_class);
+out:
+ ubi_err("UBI error: cannot initialize UBI, error %d", err);
+ return err;
+}
+module_init(ubi_init);
+
+void __exit ubi_exit(void)
+{
+ int i;
+
+ for (i = 0; i < UBI_MAX_DEVICES; i++)
+ if (ubi_devices[i]) {
+ mutex_lock(&ubi_devices_mutex);
+ ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
+ mutex_unlock(&ubi_devices_mutex);
+ }
+ kmem_cache_destroy(ubi_wl_entry_slab);
+ misc_deregister(&ubi_ctrl_cdev);
+ class_remove_file(ubi_class, &ubi_version);
+ class_destroy(ubi_class);
+}
+module_exit(ubi_exit);
+
+/**
+ * bytes_str_to_int - convert a string representing number of bytes to an
+ * integer.
+ * @str: the string to convert
+ *
+ * This function returns positive resulting integer in case of success and a
+ * negative error code in case of failure.
+ */
+static int __init bytes_str_to_int(const char *str)
+{
+ char *endp;
+ unsigned long result;
+
+ result = simple_strtoul(str, &endp, 0);
+ if (str == endp || result < 0) {
+ printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
+ str);
+ return -EINVAL;
+ }
+
+ switch (*endp) {
+ case 'G':
+ result *= 1024;
+ case 'M':
+ result *= 1024;
+ case 'K':
+ result *= 1024;
+ if (endp[1] == 'i' && endp[2] == 'B')
+ endp += 2;
+ case '\0':
+ break;
+ default:
+ printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
+ str);
+ return -EINVAL;
+ }
+
+ return result;
+}
+
+/**
+ * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
+ * @val: the parameter value to parse
+ * @kp: not used
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of error.
+ */
+int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
+{
+ int i, len;
+ struct mtd_dev_param *p;
+ char buf[MTD_PARAM_LEN_MAX];
+ char *pbuf = &buf[0];
+ char *tokens[2] = {NULL, NULL};
+
+ if (!val)
+ return -EINVAL;
+
+ if (mtd_devs == UBI_MAX_DEVICES) {
+ printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
+ UBI_MAX_DEVICES);
+ return -EINVAL;
+ }
+
+ len = strnlen(val, MTD_PARAM_LEN_MAX);
+ if (len == MTD_PARAM_LEN_MAX) {
+ printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
+ "max. is %d\n", val, MTD_PARAM_LEN_MAX);
+ return -EINVAL;
+ }
+
+ if (len == 0) {
+ printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
+ "ignored\n");
+ return 0;
+ }
+
+ strcpy(buf, val);
+
+ /* Get rid of the final newline */
+ if (buf[len - 1] == '\n')
+ buf[len - 1] = '\0';
+
+ for (i = 0; i < 2; i++)
+ tokens[i] = strsep(&pbuf, ",");
+
+ if (pbuf) {
+ printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
+ val);
+ return -EINVAL;
+ }
+
+ p = &mtd_dev_param[mtd_devs];
+ strcpy(&p->name[0], tokens[0]);
+
+ if (tokens[1])
+ p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
+
+ if (p->vid_hdr_offs < 0)
+ return p->vid_hdr_offs;
+
+ mtd_devs += 1;
+ return 0;
+}
+
+module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
+MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
+ "mtd=<name|num>[,<vid_hdr_offs>].\n"
+ "Multiple \"mtd\" parameters may be specified.\n"
+ "MTD devices may be specified by their number or name.\n"
+ "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
+ "header position and data starting position to be used "
+ "by UBI.\n"
+ "Example: mtd=content,1984 mtd=4 - attach MTD device"
+ "with name \"content\" using VID header offset 1984, and "
+ "MTD device number 4 with default VID header offset.");
+
+MODULE_VERSION(__stringify(UBI_VERSION));
+MODULE_DESCRIPTION("UBI - Unsorted Block Images");
+MODULE_AUTHOR("Artem Bityutskiy");
+MODULE_LICENSE("GPL");
--- /dev/null
+/*
+ * Oct 15, 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * Nicer crc32 functions/docs submitted by linux@horizon.com. Thanks!
+ * Code was from the public domain, copyright abandoned. Code was
+ * subsequently included in the kernel, thus was re-licensed under the
+ * GNU GPL v2.
+ *
+ * Oct 12, 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * Same crc32 function was used in 5 other places in the kernel.
+ * I made one version, and deleted the others.
+ * There are various incantations of crc32(). Some use a seed of 0 or ~0.
+ * Some xor at the end with ~0. The generic crc32() function takes
+ * seed as an argument, and doesn't xor at the end. Then individual
+ * users can do whatever they need.
+ * drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0.
+ * fs/jffs2 uses seed 0, doesn't xor with ~0.
+ * fs/partitions/efi.c uses seed ~0, xor's with ~0.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#ifdef UBI_LINUX
+#include <linux/crc32.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/compiler.h>
+#endif
+#include <linux/types.h>
+
+#include <asm/byteorder.h>
+
+#ifdef UBI_LINUX
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <asm/atomic.h>
+#endif
+#include "crc32defs.h"
+#define CRC_LE_BITS 8
+
+# define __force
+#ifndef __constant_cpu_to_le32
+#define __constant_cpu_to_le32(x) ((__force __le32)(__u32)(x))
+#endif
+#ifndef __constant_le32_to_cpu
+#define __constant_le32_to_cpu(x) ((__force __u32)(__le32)(x))
+#endif
+
+#if CRC_LE_BITS == 8
+#define tole(x) __constant_cpu_to_le32(x)
+#define tobe(x) __constant_cpu_to_be32(x)
+#else
+#define tole(x) (x)
+#define tobe(x) (x)
+#endif
+#include "crc32table.h"
+#ifdef UBI_LINUX
+MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>");
+MODULE_DESCRIPTION("Ethernet CRC32 calculations");
+MODULE_LICENSE("GPL");
+#endif
+/**
+ * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
+ * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for
+ * other uses, or the previous crc32 value if computing incrementally.
+ * @p: pointer to buffer over which CRC is run
+ * @len: length of buffer @p
+ */
+u32 crc32_le(u32 crc, unsigned char const *p, size_t len);
+
+#if CRC_LE_BITS == 1
+/*
+ * In fact, the table-based code will work in this case, but it can be
+ * simplified by inlining the table in ?: form.
+ */
+
+u32 crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+ int i;
+ while (len--) {
+ crc ^= *p++;
+ for (i = 0; i < 8; i++)
+ crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
+ }
+ return crc;
+}
+#else /* Table-based approach */
+
+u32 crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+# if CRC_LE_BITS == 8
+ const u32 *b =(u32 *)p;
+ const u32 *tab = crc32table_le;
+
+# ifdef __LITTLE_ENDIAN
+# define DO_CRC(x) crc = tab[ (crc ^ (x)) & 255 ] ^ (crc>>8)
+# else
+# define DO_CRC(x) crc = tab[ ((crc >> 24) ^ (x)) & 255] ^ (crc<<8)
+# endif
+ //printf("Crc32_le crc=%x\n",crc);
+ crc = __cpu_to_le32(crc);
+ /* Align it */
+ if((((long)b)&3 && len)){
+ do {
+ u8 *p = (u8 *)b;
+ DO_CRC(*p++);
+ b = (void *)p;
+ } while ((--len) && ((long)b)&3 );
+ }
+ if((len >= 4)){
+ /* load data 32 bits wide, xor data 32 bits wide. */
+ size_t save_len = len & 3;
+ len = len >> 2;
+ --b; /* use pre increment below(*++b) for speed */
+ do {
+ crc ^= *++b;
+ DO_CRC(0);
+ DO_CRC(0);
+ DO_CRC(0);
+ DO_CRC(0);
+ } while (--len);
+ b++; /* point to next byte(s) */
+ len = save_len;
+ }
+ /* And the last few bytes */
+ if(len){
+ do {
+ u8 *p = (u8 *)b;
+ DO_CRC(*p++);
+ b = (void *)p;
+ } while (--len);
+ }
+
+ return __le32_to_cpu(crc);
+#undef ENDIAN_SHIFT
+#undef DO_CRC
+
+# elif CRC_LE_BITS == 4
+ while (len--) {
+ crc ^= *p++;
+ crc = (crc >> 4) ^ crc32table_le[crc & 15];
+ crc = (crc >> 4) ^ crc32table_le[crc & 15];
+ }
+ return crc;
+# elif CRC_LE_BITS == 2
+ while (len--) {
+ crc ^= *p++;
+ crc = (crc >> 2) ^ crc32table_le[crc & 3];
+ crc = (crc >> 2) ^ crc32table_le[crc & 3];
+ crc = (crc >> 2) ^ crc32table_le[crc & 3];
+ crc = (crc >> 2) ^ crc32table_le[crc & 3];
+ }
+ return crc;
+# endif
+}
+#endif
+#ifdef UBI_LINUX
+/**
+ * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
+ * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for
+ * other uses, or the previous crc32 value if computing incrementally.
+ * @p: pointer to buffer over which CRC is run
+ * @len: length of buffer @p
+ */
+u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len);
+
+#if CRC_BE_BITS == 1
+/*
+ * In fact, the table-based code will work in this case, but it can be
+ * simplified by inlining the table in ?: form.
+ */
+
+u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+ int i;
+ while (len--) {
+ crc ^= *p++ << 24;
+ for (i = 0; i < 8; i++)
+ crc =
+ (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE :
+ 0);
+ }
+ return crc;
+}
+
+#else /* Table-based approach */
+u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+# if CRC_BE_BITS == 8
+ const u32 *b =(u32 *)p;
+ const u32 *tab = crc32table_be;
+
+# ifdef __LITTLE_ENDIAN
+# define DO_CRC(x) crc = tab[ (crc ^ (x)) & 255 ] ^ (crc>>8)
+# else
+# define DO_CRC(x) crc = tab[ ((crc >> 24) ^ (x)) & 255] ^ (crc<<8)
+# endif
+
+ crc = __cpu_to_be32(crc);
+ /* Align it */
+ if(unlikely(((long)b)&3 && len)){
+ do {
+ u8 *p = (u8 *)b;
+ DO_CRC(*p++);
+ b = (u32 *)p;
+ } while ((--len) && ((long)b)&3 );
+ }
+ if(likely(len >= 4)){
+ /* load data 32 bits wide, xor data 32 bits wide. */
+ size_t save_len = len & 3;
+ len = len >> 2;
+ --b; /* use pre increment below(*++b) for speed */
+ do {
+ crc ^= *++b;
+ DO_CRC(0);
+ DO_CRC(0);
+ DO_CRC(0);
+ DO_CRC(0);
+ } while (--len);
+ b++; /* point to next byte(s) */
+ len = save_len;
+ }
+ /* And the last few bytes */
+ if(len){
+ do {
+ u8 *p = (u8 *)b;
+ DO_CRC(*p++);
+ b = (void *)p;
+ } while (--len);
+ }
+ return __be32_to_cpu(crc);
+#undef ENDIAN_SHIFT
+#undef DO_CRC
+
+# elif CRC_BE_BITS == 4
+ while (len--) {
+ crc ^= *p++ << 24;
+ crc = (crc << 4) ^ crc32table_be[crc >> 28];
+ crc = (crc << 4) ^ crc32table_be[crc >> 28];
+ }
+ return crc;
+# elif CRC_BE_BITS == 2
+ while (len--) {
+ crc ^= *p++ << 24;
+ crc = (crc << 2) ^ crc32table_be[crc >> 30];
+ crc = (crc << 2) ^ crc32table_be[crc >> 30];
+ crc = (crc << 2) ^ crc32table_be[crc >> 30];
+ crc = (crc << 2) ^ crc32table_be[crc >> 30];
+ }
+ return crc;
+# endif
+}
+#endif
+
+EXPORT_SYMBOL(crc32_le);
+EXPORT_SYMBOL(crc32_be);
+#endif
+/*
+ * A brief CRC tutorial.
+ *
+ * A CRC is a long-division remainder. You add the CRC to the message,
+ * and the whole thing (message+CRC) is a multiple of the given
+ * CRC polynomial. To check the CRC, you can either check that the
+ * CRC matches the recomputed value, *or* you can check that the
+ * remainder computed on the message+CRC is 0. This latter approach
+ * is used by a lot of hardware implementations, and is why so many
+ * protocols put the end-of-frame flag after the CRC.
+ *
+ * It's actually the same long division you learned in school, except that
+ * - We're working in binary, so the digits are only 0 and 1, and
+ * - When dividing polynomials, there are no carries. Rather than add and
+ * subtract, we just xor. Thus, we tend to get a bit sloppy about
+ * the difference between adding and subtracting.
+ *
+ * A 32-bit CRC polynomial is actually 33 bits long. But since it's
+ * 33 bits long, bit 32 is always going to be set, so usually the CRC
+ * is written in hex with the most significant bit omitted. (If you're
+ * familiar with the IEEE 754 floating-point format, it's the same idea.)
+ *
+ * Note that a CRC is computed over a string of *bits*, so you have
+ * to decide on the endianness of the bits within each byte. To get
+ * the best error-detecting properties, this should correspond to the
+ * order they're actually sent. For example, standard RS-232 serial is
+ * little-endian; the most significant bit (sometimes used for parity)
+ * is sent last. And when appending a CRC word to a message, you should
+ * do it in the right order, matching the endianness.
+ *
+ * Just like with ordinary division, the remainder is always smaller than
+ * the divisor (the CRC polynomial) you're dividing by. Each step of the
+ * division, you take one more digit (bit) of the dividend and append it
+ * to the current remainder. Then you figure out the appropriate multiple
+ * of the divisor to subtract to being the remainder back into range.
+ * In binary, it's easy - it has to be either 0 or 1, and to make the
+ * XOR cancel, it's just a copy of bit 32 of the remainder.
+ *
+ * When computing a CRC, we don't care about the quotient, so we can
+ * throw the quotient bit away, but subtract the appropriate multiple of
+ * the polynomial from the remainder and we're back to where we started,
+ * ready to process the next bit.
+ *
+ * A big-endian CRC written this way would be coded like:
+ * for (i = 0; i < input_bits; i++) {
+ * multiple = remainder & 0x80000000 ? CRCPOLY : 0;
+ * remainder = (remainder << 1 | next_input_bit()) ^ multiple;
+ * }
+ * Notice how, to get at bit 32 of the shifted remainder, we look
+ * at bit 31 of the remainder *before* shifting it.
+ *
+ * But also notice how the next_input_bit() bits we're shifting into
+ * the remainder don't actually affect any decision-making until
+ * 32 bits later. Thus, the first 32 cycles of this are pretty boring.
+ * Also, to add the CRC to a message, we need a 32-bit-long hole for it at
+ * the end, so we have to add 32 extra cycles shifting in zeros at the
+ * end of every message,
+ *
+ * So the standard trick is to rearrage merging in the next_input_bit()
+ * until the moment it's needed. Then the first 32 cycles can be precomputed,
+ * and merging in the final 32 zero bits to make room for the CRC can be
+ * skipped entirely.
+ * This changes the code to:
+ * for (i = 0; i < input_bits; i++) {
+ * remainder ^= next_input_bit() << 31;
+ * multiple = (remainder & 0x80000000) ? CRCPOLY : 0;
+ * remainder = (remainder << 1) ^ multiple;
+ * }
+ * With this optimization, the little-endian code is simpler:
+ * for (i = 0; i < input_bits; i++) {
+ * remainder ^= next_input_bit();
+ * multiple = (remainder & 1) ? CRCPOLY : 0;
+ * remainder = (remainder >> 1) ^ multiple;
+ * }
+ *
+ * Note that the other details of endianness have been hidden in CRCPOLY
+ * (which must be bit-reversed) and next_input_bit().
+ *
+ * However, as long as next_input_bit is returning the bits in a sensible
+ * order, we can actually do the merging 8 or more bits at a time rather
+ * than one bit at a time:
+ * for (i = 0; i < input_bytes; i++) {
+ * remainder ^= next_input_byte() << 24;
+ * for (j = 0; j < 8; j++) {
+ * multiple = (remainder & 0x80000000) ? CRCPOLY : 0;
+ * remainder = (remainder << 1) ^ multiple;
+ * }
+ * }
+ * Or in little-endian:
+ * for (i = 0; i < input_bytes; i++) {
+ * remainder ^= next_input_byte();
+ * for (j = 0; j < 8; j++) {
+ * multiple = (remainder & 1) ? CRCPOLY : 0;
+ * remainder = (remainder << 1) ^ multiple;
+ * }
+ * }
+ * If the input is a multiple of 32 bits, you can even XOR in a 32-bit
+ * word at a time and increase the inner loop count to 32.
+ *
+ * You can also mix and match the two loop styles, for example doing the
+ * bulk of a message byte-at-a-time and adding bit-at-a-time processing
+ * for any fractional bytes at the end.
+ *
+ * The only remaining optimization is to the byte-at-a-time table method.
+ * Here, rather than just shifting one bit of the remainder to decide
+ * in the correct multiple to subtract, we can shift a byte at a time.
+ * This produces a 40-bit (rather than a 33-bit) intermediate remainder,
+ * but again the multiple of the polynomial to subtract depends only on
+ * the high bits, the high 8 bits in this case.
+ *
+ * The multile we need in that case is the low 32 bits of a 40-bit
+ * value whose high 8 bits are given, and which is a multiple of the
+ * generator polynomial. This is simply the CRC-32 of the given
+ * one-byte message.
+ *
+ * Two more details: normally, appending zero bits to a message which
+ * is already a multiple of a polynomial produces a larger multiple of that
+ * polynomial. To enable a CRC to detect this condition, it's common to
+ * invert the CRC before appending it. This makes the remainder of the
+ * message+crc come out not as zero, but some fixed non-zero value.
+ *
+ * The same problem applies to zero bits prepended to the message, and
+ * a similar solution is used. Instead of starting with a remainder of
+ * 0, an initial remainder of all ones is used. As long as you start
+ * the same way on decoding, it doesn't make a difference.
+ */
+
+#ifdef UNITTEST
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#ifdef UBI_LINUX /*Not used at present */
+static void
+buf_dump(char const *prefix, unsigned char const *buf, size_t len)
+{
+ fputs(prefix, stdout);
+ while (len--)
+ printf(" %02x", *buf++);
+ putchar('\n');
+
+}
+#endif
+
+static void bytereverse(unsigned char *buf, size_t len)
+{
+ while (len--) {
+ unsigned char x = bitrev8(*buf);
+ *buf++ = x;
+ }
+}
+
+static void random_garbage(unsigned char *buf, size_t len)
+{
+ while (len--)
+ *buf++ = (unsigned char) random();
+}
+
+#ifdef UBI_LINUX /* Not used at present */
+static void store_le(u32 x, unsigned char *buf)
+{
+ buf[0] = (unsigned char) x;
+ buf[1] = (unsigned char) (x >> 8);
+ buf[2] = (unsigned char) (x >> 16);
+ buf[3] = (unsigned char) (x >> 24);
+}
+#endif
+
+static void store_be(u32 x, unsigned char *buf)
+{
+ buf[0] = (unsigned char) (x >> 24);
+ buf[1] = (unsigned char) (x >> 16);
+ buf[2] = (unsigned char) (x >> 8);
+ buf[3] = (unsigned char) x;
+}
+
+/*
+ * This checks that CRC(buf + CRC(buf)) = 0, and that
+ * CRC commutes with bit-reversal. This has the side effect
+ * of bytewise bit-reversing the input buffer, and returns
+ * the CRC of the reversed buffer.
+ */
+static u32 test_step(u32 init, unsigned char *buf, size_t len)
+{
+ u32 crc1, crc2;
+ size_t i;
+
+ crc1 = crc32_be(init, buf, len);
+ store_be(crc1, buf + len);
+ crc2 = crc32_be(init, buf, len + 4);
+ if (crc2)
+ printf("\nCRC cancellation fail: 0x%08x should be 0\n",
+ crc2);
+
+ for (i = 0; i <= len + 4; i++) {
+ crc2 = crc32_be(init, buf, i);
+ crc2 = crc32_be(crc2, buf + i, len + 4 - i);
+ if (crc2)
+ printf("\nCRC split fail: 0x%08x\n", crc2);
+ }
+
+ /* Now swap it around for the other test */
+
+ bytereverse(buf, len + 4);
+ init = bitrev32(init);
+ crc2 = bitrev32(crc1);
+ if (crc1 != bitrev32(crc2))
+ printf("\nBit reversal fail: 0x%08x -> 0x%08x -> 0x%08x\n",
+ crc1, crc2, bitrev32(crc2));
+ crc1 = crc32_le(init, buf, len);
+ if (crc1 != crc2)
+ printf("\nCRC endianness fail: 0x%08x != 0x%08x\n", crc1,
+ crc2);
+ crc2 = crc32_le(init, buf, len + 4);
+ if (crc2)
+ printf("\nCRC cancellation fail: 0x%08x should be 0\n",
+ crc2);
+
+ for (i = 0; i <= len + 4; i++) {
+ crc2 = crc32_le(init, buf, i);
+ crc2 = crc32_le(crc2, buf + i, len + 4 - i);
+ if (crc2)
+ printf("\nCRC split fail: 0x%08x\n", crc2);
+ }
+
+ return crc1;
+}
+
+#define SIZE 64
+#define INIT1 0
+#define INIT2 0
+
+int main(void)
+{
+ unsigned char buf1[SIZE + 4];
+ unsigned char buf2[SIZE + 4];
+ unsigned char buf3[SIZE + 4];
+ int i, j;
+ u32 crc1, crc2, crc3;
+
+ for (i = 0; i <= SIZE; i++) {
+ printf("\rTesting length %d...", i);
+ fflush(stdout);
+ random_garbage(buf1, i);
+ random_garbage(buf2, i);
+ for (j = 0; j < i; j++)
+ buf3[j] = buf1[j] ^ buf2[j];
+
+ crc1 = test_step(INIT1, buf1, i);
+ crc2 = test_step(INIT2, buf2, i);
+ /* Now check that CRC(buf1 ^ buf2) = CRC(buf1) ^ CRC(buf2) */
+ crc3 = test_step(INIT1 ^ INIT2, buf3, i);
+ if (crc3 != (crc1 ^ crc2))
+ printf("CRC XOR fail: 0x%08x != 0x%08x ^ 0x%08x\n",
+ crc3, crc1, crc2);
+ }
+ printf("\nAll test complete. No failures expected.\n");
+ return 0;
+}
+
+#endif /* UNITTEST */
projects / u-boot / commitdiff