Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 897 insertions, 0 deletions

diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
new file mode 100644
index 000000000..c97167d51
--- /dev/null
+++ b/drivers/mtd/mtdconcat.c
@@ -0,0 +1,897 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MTD device concatenation layer
+ *
+ * Copyright © 2002 Robert Kaiser <rkaiser@sysgo.de>
+ * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * NAND support by Christian Gan <cgan@iders.ca>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/backing-dev.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/concat.h>
+
+#include <asm/div64.h>
+
+/*
+ * how to calculate the size required for the above structure,
+ * including the pointer array subdev points to:
+ */
+#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev)	\
+	((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
+
+/*
+ * Given a pointer to the MTD object in the mtd_concat structure,
+ * we can retrieve the pointer to that structure with this macro.
+ */
+#define CONCAT(x)  ((struct mtd_concat *)(x))
+
+/*
+ * MTD methods which look up the relevant subdevice, translate the
+ * effective address and pass through to the subdevice.
+ */
+
+static int
+concat_read(struct mtd_info *mtd, loff_t from, size_t len,
+	    size_t * retlen, u_char * buf)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int ret = 0, err;
+	int i;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		size_t size, retsize;
+
+		if (from >= subdev->size) {
+			/* Not destined for this subdev */
+			size = 0;
+			from -= subdev->size;
+			continue;
+		}
+		if (from + len > subdev->size)
+			/* First part goes into this subdev */
+			size = subdev->size - from;
+		else
+			/* Entire transaction goes into this subdev */
+			size = len;
+
+		err = mtd_read(subdev, from, size, &retsize, buf);
+
+		/* Save information about bitflips! */
+		if (unlikely(err)) {
+			if (mtd_is_eccerr(err)) {
+				mtd->ecc_stats.failed++;
+				ret = err;
+			} else if (mtd_is_bitflip(err)) {
+				mtd->ecc_stats.corrected++;
+				/* Do not overwrite -EBADMSG !! */
+				if (!ret)
+					ret = err;
+			} else
+				return err;
+		}
+
+		*retlen += retsize;
+		len -= size;
+		if (len == 0)
+			return ret;
+
+		buf += size;
+		from = 0;
+	}
+	return -EINVAL;
+}
+
+static int
+concat_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
+	     size_t * retlen, const u_char * buf)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int err = -EINVAL;
+	int i;
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		size_t size, retsize;
+
+		if (to >= subdev->size) {
+			to -= subdev->size;
+			continue;
+		}
+		if (to + len > subdev->size)
+			size = subdev->size - to;
+		else
+			size = len;
+
+		err = mtd_panic_write(subdev, to, size, &retsize, buf);
+		if (err == -EOPNOTSUPP) {
+			printk(KERN_ERR "mtdconcat: Cannot write from panic without panic_write\n");
+			return err;
+		}
+		if (err)
+			break;
+
+		*retlen += retsize;
+		len -= size;
+		if (len == 0)
+			break;
+
+		err = -EINVAL;
+		buf += size;
+		to = 0;
+	}
+	return err;
+}
+
+
+static int
+concat_write(struct mtd_info *mtd, loff_t to, size_t len,
+	     size_t * retlen, const u_char * buf)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int err = -EINVAL;
+	int i;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		size_t size, retsize;
+
+		if (to >= subdev->size) {
+			size = 0;
+			to -= subdev->size;
+			continue;
+		}
+		if (to + len > subdev->size)
+			size = subdev->size - to;
+		else
+			size = len;
+
+		err = mtd_write(subdev, to, size, &retsize, buf);
+		if (err)
+			break;
+
+		*retlen += retsize;
+		len -= size;
+		if (len == 0)
+			break;
+
+		err = -EINVAL;
+		buf += size;
+		to = 0;
+	}
+	return err;
+}
+
+static int
+concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
+		unsigned long count, loff_t to, size_t * retlen)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	struct kvec *vecs_copy;
+	unsigned long entry_low, entry_high;
+	size_t total_len = 0;
+	int i;
+	int err = -EINVAL;
+
+	/* Calculate total length of data */
+	for (i = 0; i < count; i++)
+		total_len += vecs[i].iov_len;
+
+	/* Check alignment */
+	if (mtd->writesize > 1) {
+		uint64_t __to = to;
+		if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
+			return -EINVAL;
+	}
+
+	/* make a copy of vecs */
+	vecs_copy = kmemdup_array(vecs, count, sizeof(struct kvec), GFP_KERNEL);
+	if (!vecs_copy)
+		return -ENOMEM;
+
+	entry_low = 0;
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		size_t size, wsize, retsize, old_iov_len;
+
+		if (to >= subdev->size) {
+			to -= subdev->size;
+			continue;
+		}
+
+		size = min_t(uint64_t, total_len, subdev->size - to);
+		wsize = size; /* store for future use */
+
+		entry_high = entry_low;
+		while (entry_high < count) {
+			if (size <= vecs_copy[entry_high].iov_len)
+				break;
+			size -= vecs_copy[entry_high++].iov_len;
+		}
+
+		old_iov_len = vecs_copy[entry_high].iov_len;
+		vecs_copy[entry_high].iov_len = size;
+
+		err = mtd_writev(subdev, &vecs_copy[entry_low],
+				 entry_high - entry_low + 1, to, &retsize);
+
+		vecs_copy[entry_high].iov_len = old_iov_len - size;
+		vecs_copy[entry_high].iov_base += size;
+
+		entry_low = entry_high;
+
+		if (err)
+			break;
+
+		*retlen += retsize;
+		total_len -= wsize;
+
+		if (total_len == 0)
+			break;
+
+		err = -EINVAL;
+		to = 0;
+	}
+
+	kfree(vecs_copy);
+	return err;
+}
+
+static int
+concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	struct mtd_oob_ops devops = *ops;
+	int i, err, ret = 0;
+
+	ops->retlen = ops->oobretlen = 0;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+
+		if (from >= subdev->size) {
+			from -= subdev->size;
+			continue;
+		}
+
+		/* partial read ? */
+		if (from + devops.len > subdev->size)
+			devops.len = subdev->size - from;
+
+		err = mtd_read_oob(subdev, from, &devops);
+		ops->retlen += devops.retlen;
+		ops->oobretlen += devops.oobretlen;
+
+		/* Save information about bitflips! */
+		if (unlikely(err)) {
+			if (mtd_is_eccerr(err)) {
+				mtd->ecc_stats.failed++;
+				ret = err;
+			} else if (mtd_is_bitflip(err)) {
+				mtd->ecc_stats.corrected++;
+				/* Do not overwrite -EBADMSG !! */
+				if (!ret)
+					ret = err;
+			} else
+				return err;
+		}
+
+		if (devops.datbuf) {
+			devops.len = ops->len - ops->retlen;
+			if (!devops.len)
+				return ret;
+			devops.datbuf += devops.retlen;
+		}
+		if (devops.oobbuf) {
+			devops.ooblen = ops->ooblen - ops->oobretlen;
+			if (!devops.ooblen)
+				return ret;
+			devops.oobbuf += ops->oobretlen;
+		}
+
+		from = 0;
+	}
+	return -EINVAL;
+}
+
+static int
+concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	struct mtd_oob_ops devops = *ops;
+	int i, err;
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+
+	ops->retlen = ops->oobretlen = 0;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+
+		if (to >= subdev->size) {
+			to -= subdev->size;
+			continue;
+		}
+
+		/* partial write ? */
+		if (to + devops.len > subdev->size)
+			devops.len = subdev->size - to;
+
+		err = mtd_write_oob(subdev, to, &devops);
+		ops->retlen += devops.retlen;
+		ops->oobretlen += devops.oobretlen;
+		if (err)
+			return err;
+
+		if (devops.datbuf) {
+			devops.len = ops->len - ops->retlen;
+			if (!devops.len)
+				return 0;
+			devops.datbuf += devops.retlen;
+		}
+		if (devops.oobbuf) {
+			devops.ooblen = ops->ooblen - ops->oobretlen;
+			if (!devops.ooblen)
+				return 0;
+			devops.oobbuf += devops.oobretlen;
+		}
+		to = 0;
+	}
+	return -EINVAL;
+}
+
+static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	struct mtd_info *subdev;
+	int i, err;
+	uint64_t length, offset = 0;
+	struct erase_info *erase;
+
+	/*
+	 * Check for proper erase block alignment of the to-be-erased area.
+	 * It is easier to do this based on the super device's erase
+	 * region info rather than looking at each particular sub-device
+	 * in turn.
+	 */
+	if (!concat->mtd.numeraseregions) {
+		/* the easy case: device has uniform erase block size */
+		if (instr->addr & (concat->mtd.erasesize - 1))
+			return -EINVAL;
+		if (instr->len & (concat->mtd.erasesize - 1))
+			return -EINVAL;
+	} else {
+		/* device has variable erase size */
+		struct mtd_erase_region_info *erase_regions =
+		    concat->mtd.eraseregions;
+
+		/*
+		 * Find the erase region where the to-be-erased area begins:
+		 */
+		for (i = 0; i < concat->mtd.numeraseregions &&
+		     instr->addr >= erase_regions[i].offset; i++) ;
+		--i;
+
+		/*
+		 * Now erase_regions[i] is the region in which the
+		 * to-be-erased area begins. Verify that the starting
+		 * offset is aligned to this region's erase size:
+		 */
+		if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))
+			return -EINVAL;
+
+		/*
+		 * now find the erase region where the to-be-erased area ends:
+		 */
+		for (; i < concat->mtd.numeraseregions &&
+		     (instr->addr + instr->len) >= erase_regions[i].offset;
+		     ++i) ;
+		--i;
+		/*
+		 * check if the ending offset is aligned to this region's erase size
+		 */
+		if (i < 0 || ((instr->addr + instr->len) &
+					(erase_regions[i].erasesize - 1)))
+			return -EINVAL;
+	}
+
+	/* make a local copy of instr to avoid modifying the caller's struct */
+	erase = kmalloc_obj(struct erase_info);
+
+	if (!erase)
+		return -ENOMEM;
+
+	*erase = *instr;
+	length = instr->len;
+
+	/*
+	 * find the subdevice where the to-be-erased area begins, adjust
+	 * starting offset to be relative to the subdevice start
+	 */
+	for (i = 0; i < concat->num_subdev; i++) {
+		subdev = concat->subdev[i];
+		if (subdev->size <= erase->addr) {
+			erase->addr -= subdev->size;
+			offset += subdev->size;
+		} else {
+			break;
+		}
+	}
+
+	/* must never happen since size limit has been verified above */
+	BUG_ON(i >= concat->num_subdev);
+
+	/* now do the erase: */
+	err = 0;
+	for (; length > 0; i++) {
+		/* loop for all subdevices affected by this request */
+		subdev = concat->subdev[i];	/* get current subdevice */
+
+		/* limit length to subdevice's size: */
+		if (erase->addr + length > subdev->size)
+			erase->len = subdev->size - erase->addr;
+		else
+			erase->len = length;
+
+		length -= erase->len;
+		if ((err = mtd_erase(subdev, erase))) {
+			/* sanity check: should never happen since
+			 * block alignment has been checked above */
+			BUG_ON(err == -EINVAL);
+			if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
+				instr->fail_addr = erase->fail_addr + offset;
+			break;
+		}
+		/*
+		 * erase->addr specifies the offset of the area to be
+		 * erased *within the current subdevice*. It can be
+		 * non-zero only the first time through this loop, i.e.
+		 * for the first subdevice where blocks need to be erased.
+		 * All the following erases must begin at the start of the
+		 * current subdevice, i.e. at offset zero.
+		 */
+		erase->addr = 0;
+		offset += subdev->size;
+	}
+	kfree(erase);
+
+	return err;
+}
+
+static int concat_xxlock(struct mtd_info *mtd, loff_t ofs, uint64_t len,
+			 bool is_lock)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int i, err = -EINVAL;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		uint64_t size;
+
+		if (ofs >= subdev->size) {
+			size = 0;
+			ofs -= subdev->size;
+			continue;
+		}
+		if (ofs + len > subdev->size)
+			size = subdev->size - ofs;
+		else
+			size = len;
+
+		if (is_lock)
+			err = mtd_lock(subdev, ofs, size);
+		else
+			err = mtd_unlock(subdev, ofs, size);
+		if (err)
+			break;
+
+		len -= size;
+		if (len == 0)
+			break;
+
+		err = -EINVAL;
+		ofs = 0;
+	}
+
+	return err;
+}
+
+static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+	return concat_xxlock(mtd, ofs, len, true);
+}
+
+static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+	return concat_xxlock(mtd, ofs, len, false);
+}
+
+static int concat_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int i, err = -EINVAL;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+
+		if (ofs >= subdev->size) {
+			ofs -= subdev->size;
+			continue;
+		}
+
+		if (ofs + len > subdev->size)
+			break;
+
+		return mtd_is_locked(subdev, ofs, len);
+	}
+
+	return err;
+}
+
+static void concat_sync(struct mtd_info *mtd)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int i;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		mtd_sync(subdev);
+	}
+}
+
+static int concat_suspend(struct mtd_info *mtd)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int i, rc = 0;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		if ((rc = mtd_suspend(subdev)) < 0)
+			return rc;
+	}
+	return rc;
+}
+
+static void concat_resume(struct mtd_info *mtd)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int i;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+		mtd_resume(subdev);
+	}
+}
+
+static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int i, res = 0;
+
+	if (!mtd_can_have_bb(concat->subdev[0]))
+		return res;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+
+		if (ofs >= subdev->size) {
+			ofs -= subdev->size;
+			continue;
+		}
+
+		res = mtd_block_isbad(subdev, ofs);
+		break;
+	}
+
+	return res;
+}
+
+static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	int i, err = -EINVAL;
+
+	for (i = 0; i < concat->num_subdev; i++) {
+		struct mtd_info *subdev = concat->subdev[i];
+
+		if (ofs >= subdev->size) {
+			ofs -= subdev->size;
+			continue;
+		}
+
+		err = mtd_block_markbad(subdev, ofs);
+		if (!err)
+			mtd->ecc_stats.badblocks++;
+		break;
+	}
+
+	return err;
+}
+
+/*
+ * This function constructs a virtual MTD device by concatenating
+ * num_devs MTD devices. A pointer to the new device object is
+ * stored to *new_dev upon success. This function does _not_
+ * register any devices: this is the caller's responsibility.
+ */
+struct mtd_info *mtd_concat_create(struct mtd_info *subdev[],	/* subdevices to concatenate */
+				   int num_devs,	/* number of subdevices      */
+				   const char *name)
+{				/* name for the new device   */
+	int i;
+	struct mtd_concat *concat;
+	struct mtd_info *subdev_master = NULL;
+	uint32_t max_erasesize, curr_erasesize;
+	int num_erase_region;
+	int max_writebufsize = 0;
+
+	printk(KERN_NOTICE "Concatenating MTD devices:\n");
+	for (i = 0; i < num_devs; i++)
+		printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
+	printk(KERN_NOTICE "into device \"%s\"\n", name);
+
+	/* allocate the device structure */
+	concat = kzalloc_flex(*concat, subdev, num_devs, GFP_KERNEL);
+	if (!concat) {
+		printk
+		    ("memory allocation error while creating concatenated device \"%s\"\n",
+		     name);
+		return NULL;
+	}
+
+	/*
+	 * Set up the new "super" device's MTD object structure, check for
+	 * incompatibilities between the subdevices.
+	 */
+	concat->mtd.type = subdev[0]->type;
+	concat->mtd.flags = subdev[0]->flags;
+	concat->mtd.size = subdev[0]->size;
+	concat->mtd.erasesize = subdev[0]->erasesize;
+	concat->mtd.writesize = subdev[0]->writesize;
+
+	for (i = 0; i < num_devs; i++)
+		if (max_writebufsize < subdev[i]->writebufsize)
+			max_writebufsize = subdev[i]->writebufsize;
+	concat->mtd.writebufsize = max_writebufsize;
+
+	concat->mtd.subpage_sft = subdev[0]->subpage_sft;
+	concat->mtd.oobsize = subdev[0]->oobsize;
+	concat->mtd.oobavail = subdev[0]->oobavail;
+
+	subdev_master = mtd_get_master(subdev[0]);
+	if (subdev_master->_writev)
+		concat->mtd._writev = concat_writev;
+	if (subdev_master->_read_oob)
+		concat->mtd._read_oob = concat_read_oob;
+	if (subdev_master->_write_oob)
+		concat->mtd._write_oob = concat_write_oob;
+	if (subdev_master->_block_isbad)
+		concat->mtd._block_isbad = concat_block_isbad;
+	if (subdev_master->_block_markbad)
+		concat->mtd._block_markbad = concat_block_markbad;
+	if (subdev_master->_panic_write)
+		concat->mtd._panic_write = concat_panic_write;
+	if (subdev_master->_read)
+		concat->mtd._read = concat_read;
+	if (subdev_master->_write)
+		concat->mtd._write = concat_write;
+
+	concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
+
+	concat->subdev[0] = subdev[0];
+
+	for (i = 1; i < num_devs; i++) {
+		if (concat->mtd.type != subdev[i]->type) {
+			kfree(concat);
+			printk("Incompatible device type on \"%s\"\n",
+			       subdev[i]->name);
+			return NULL;
+		}
+		if (concat->mtd.flags != subdev[i]->flags) {
+			/*
+			 * Expect all flags except MTD_WRITEABLE to be
+			 * equal on all subdevices.
+			 */
+			if ((concat->mtd.flags ^ subdev[i]->
+			     flags) & ~MTD_WRITEABLE) {
+				kfree(concat);
+				printk("Incompatible device flags on \"%s\"\n",
+				       subdev[i]->name);
+				return NULL;
+			} else
+				/* if writeable attribute differs,
+				   make super device writeable */
+				concat->mtd.flags |=
+				    subdev[i]->flags & MTD_WRITEABLE;
+		}
+
+		subdev_master = mtd_get_master(subdev[i]);
+		concat->mtd.size += subdev[i]->size;
+		concat->mtd.ecc_stats.badblocks +=
+			subdev[i]->ecc_stats.badblocks;
+		if (concat->mtd.writesize   !=  subdev[i]->writesize ||
+		    concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
+		    concat->mtd.oobsize    !=  subdev[i]->oobsize ||
+		    !concat->mtd._read_oob  != !subdev_master->_read_oob ||
+		    !concat->mtd._write_oob != !subdev_master->_write_oob) {
+			/*
+			 * Check against subdev[i] for data members, because
+			 * subdev's attributes may be different from master
+			 * mtd device. Check against subdev's master mtd
+			 * device for callbacks, because the existence of
+			 * subdev's callbacks is decided by master mtd device.
+			 */
+			kfree(concat);
+			printk("Incompatible OOB or ECC data on \"%s\"\n",
+			       subdev[i]->name);
+			return NULL;
+		}
+		concat->subdev[i] = subdev[i];
+
+	}
+
+	mtd_set_ooblayout(&concat->mtd, subdev[0]->ooblayout);
+
+	concat->num_subdev = num_devs;
+	concat->mtd.name = name;
+
+	concat->mtd._erase = concat_erase;
+	concat->mtd._sync = concat_sync;
+	concat->mtd._lock = concat_lock;
+	concat->mtd._unlock = concat_unlock;
+	concat->mtd._is_locked = concat_is_locked;
+	concat->mtd._suspend = concat_suspend;
+	concat->mtd._resume = concat_resume;
+
+	/*
+	 * Combine the erase block size info of the subdevices:
+	 *
+	 * first, walk the map of the new device and see how
+	 * many changes in erase size we have
+	 */
+	max_erasesize = curr_erasesize = subdev[0]->erasesize;
+	num_erase_region = 1;
+	for (i = 0; i < num_devs; i++) {
+		if (subdev[i]->numeraseregions == 0) {
+			/* current subdevice has uniform erase size */
+			if (subdev[i]->erasesize != curr_erasesize) {
+				/* if it differs from the last subdevice's erase size, count it */
+				++num_erase_region;
+				curr_erasesize = subdev[i]->erasesize;
+				if (curr_erasesize > max_erasesize)
+					max_erasesize = curr_erasesize;
+			}
+		} else {
+			/* current subdevice has variable erase size */
+			int j;
+			for (j = 0; j < subdev[i]->numeraseregions; j++) {
+
+				/* walk the list of erase regions, count any changes */
+				if (subdev[i]->eraseregions[j].erasesize !=
+				    curr_erasesize) {
+					++num_erase_region;
+					curr_erasesize =
+					    subdev[i]->eraseregions[j].
+					    erasesize;
+					if (curr_erasesize > max_erasesize)
+						max_erasesize = curr_erasesize;
+				}
+			}
+		}
+	}
+
+	if (num_erase_region == 1) {
+		/*
+		 * All subdevices have the same uniform erase size.
+		 * This is easy:
+		 */
+		concat->mtd.erasesize = curr_erasesize;
+		concat->mtd.numeraseregions = 0;
+	} else {
+		uint64_t tmp64;
+
+		/*
+		 * erase block size varies across the subdevices: allocate
+		 * space to store the data describing the variable erase regions
+		 */
+		struct mtd_erase_region_info *erase_region_p;
+		uint64_t begin, position;
+
+		concat->mtd.erasesize = max_erasesize;
+		concat->mtd.numeraseregions = num_erase_region;
+		concat->mtd.eraseregions = erase_region_p =
+		    kmalloc_objs(struct mtd_erase_region_info, num_erase_region);
+		if (!erase_region_p) {
+			kfree(concat);
+			printk
+			    ("memory allocation error while creating erase region list"
+			     " for device \"%s\"\n", name);
+			return NULL;
+		}
+
+		/*
+		 * walk the map of the new device once more and fill in
+		 * erase region info:
+		 */
+		curr_erasesize = subdev[0]->erasesize;
+		begin = position = 0;
+		for (i = 0; i < num_devs; i++) {
+			if (subdev[i]->numeraseregions == 0) {
+				/* current subdevice has uniform erase size */
+				if (subdev[i]->erasesize != curr_erasesize) {
+					/*
+					 *  fill in an mtd_erase_region_info structure for the area
+					 *  we have walked so far:
+					 */
+					erase_region_p->offset = begin;
+					erase_region_p->erasesize =
+					    curr_erasesize;
+					tmp64 = position - begin;
+					do_div(tmp64, curr_erasesize);
+					erase_region_p->numblocks = tmp64;
+					begin = position;
+
+					curr_erasesize = subdev[i]->erasesize;
+					++erase_region_p;
+				}
+				position += subdev[i]->size;
+			} else {
+				/* current subdevice has variable erase size */
+				int j;
+				for (j = 0; j < subdev[i]->numeraseregions; j++) {
+					/* walk the list of erase regions, count any changes */
+					if (subdev[i]->eraseregions[j].
+					    erasesize != curr_erasesize) {
+						erase_region_p->offset = begin;
+						erase_region_p->erasesize =
+						    curr_erasesize;
+						tmp64 = position - begin;
+						do_div(tmp64, curr_erasesize);
+						erase_region_p->numblocks = tmp64;
+						begin = position;
+
+						curr_erasesize =
+						    subdev[i]->eraseregions[j].
+						    erasesize;
+						++erase_region_p;
+					}
+					position +=
+					    subdev[i]->eraseregions[j].
+					    numblocks * (uint64_t)curr_erasesize;
+				}
+			}
+		}
+		/* Now write the final entry */
+		erase_region_p->offset = begin;
+		erase_region_p->erasesize = curr_erasesize;
+		tmp64 = position - begin;
+		do_div(tmp64, curr_erasesize);
+		erase_region_p->numblocks = tmp64;
+	}
+
+	return &concat->mtd;
+}
+
+/* Cleans the context obtained from mtd_concat_create() */
+void mtd_concat_destroy(struct mtd_info *mtd)
+{
+	struct mtd_concat *concat = CONCAT(mtd);
+	if (concat->mtd.numeraseregions)
+		kfree(concat->mtd.eraseregions);
+	kfree(concat);
+}
+
+EXPORT_SYMBOL(mtd_concat_create);
+EXPORT_SYMBOL(mtd_concat_destroy);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
+MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");