MTD: mtdconcat NAND/Sibley support (rev.2)

There is a second revision of "mtdconcat NAND/Sibley" patch. I hope
the patch will not get damaged as I'm posting it from gmail account,
thanks to Jorn.

The patch adds previously missing concat_writev(),
concat_writev_ecc(), concat_block_isbad(), concat_block_markbad()
functions to make concatenation layer compatible with Sibley and NAND
chips.

Patch has been cleared from whitespaces, fixed some lines of code as
requested. Also I have added code for alignment check that should
support Jorn's "writesize" patch.

Signed-off-by: Alexander Belyakov <alexander.belyakov@intel.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 164 insertions, 5 deletions

diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index 9af840364a74..da4c9c190bb3 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -251,6 +251,106 @@ concat_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
 }
 
 static int
+concat_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs,
+                unsigned long count, loff_t to, size_t * retlen,
+                u_char *eccbuf, struct nand_oobinfo *oobsel)
+{
+        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;
+
+        if (!(mtd->flags & MTD_WRITEABLE))
+                return -EROFS;
+
+        *retlen = 0;
+
+        /* Calculate total length of data */
+        for (i = 0; i < count; i++)
+                total_len += vecs[i].iov_len;
+
+        /* Do not allow write past end of device */
+        if ((to + total_len) > mtd->size)
+                return -EINVAL;
+
+        /* Check alignment */
+        if (mtd->writesize > 1)
+                if ((to % mtd->writesize) || (total_len % mtd->writesize))
+                        return -EINVAL;
+
+        /* make a copy of vecs */
+        vecs_copy = kmalloc(sizeof(struct kvec) * count, GFP_KERNEL);
+        if (!vecs_copy)
+                return -ENOMEM;
+        memcpy(vecs_copy, vecs, sizeof(struct kvec) * count);
+
+        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(total_len, (size_t)(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;
+
+                if (!(subdev->flags & MTD_WRITEABLE))
+                        err = -EROFS;
+                else if (eccbuf)
+                        err = subdev->writev_ecc(subdev, &vecs_copy[entry_low],
+                                entry_high - entry_low + 1, to, &retsize,
+                                eccbuf, oobsel);
+                else
+                        err = subdev->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 (concat->mtd.type == MTD_NANDFLASH && eccbuf)
+                        eccbuf += mtd->oobavail * (wsize / mtd->oobblock);
+
+                if (total_len == 0)
+                        break;
+
+                err = -EINVAL;
+                to = 0;
+        }
+
+        kfree(vecs_copy);
+        return err;
+}
+
+static int
+concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
+                unsigned long count, loff_t to, size_t * retlen)
+{
+        return concat_writev_ecc(mtd, vecs, count, to, retlen, NULL, NULL);
+}
+
+static int
 concat_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
                 size_t * retlen, u_char * buf)
 {
@@ -636,6 +736,58 @@ static void concat_resume(struct mtd_info *mtd)
         }
 }
 
+static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
+        struct mtd_concat *concat = CONCAT(mtd);
+        int i, res = 0;
+
+        if (!concat->subdev[0]->block_isbad)
+                return res;
+
+        if (ofs > mtd->size)
+                return -EINVAL;
+
+        for (i = 0; i < concat->num_subdev; i++) {
+                struct mtd_info *subdev = concat->subdev[i];
+
+                if (ofs >= subdev->size) {
+                        ofs -= subdev->size;
+                        continue;
+                }
+
+                res = subdev->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;
+
+        if (!concat->subdev[0]->block_markbad)
+                return 0;
+
+        if (ofs > mtd->size)
+                return -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 = subdev->block_markbad(subdev, ofs);
+                break;
+        }
+
+        return err;
+}
+
 /*
  * This function constructs a virtual MTD device by concatenating
  * num_devs MTD devices. A pointer to the new device object is
@@ -685,10 +837,18 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[],	/* subdevices to c
                 concat->mtd.read_ecc = concat_read_ecc;
         if (subdev[0]->write_ecc)
                 concat->mtd.write_ecc = concat_write_ecc;
+        if (subdev[0]->writev)
+                concat->mtd.writev = concat_writev;
+        if (subdev[0]->writev_ecc)
+                concat->mtd.writev_ecc = concat_writev_ecc;
         if (subdev[0]->read_oob)
                 concat->mtd.read_oob = concat_read_oob;
         if (subdev[0]->write_oob)
                 concat->mtd.write_oob = concat_write_oob;
+        if (subdev[0]->block_isbad)
+                concat->mtd.block_isbad = concat_block_isbad;
+        if (subdev[0]->block_markbad)
+                concat->mtd.block_markbad = concat_block_markbad;
 
         concat->subdev[0] = subdev[0];
 
@@ -734,14 +894,13 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[],	/* subdevices to c
 
         }
 
+        if(concat->mtd.type == MTD_NANDFLASH)
+                memcpy(&concat->mtd.oobinfo, &subdev[0]->oobinfo,
+                        sizeof(struct nand_oobinfo));
+
         concat->num_subdev = num_devs;
         concat->mtd.name = name;
 
-        /*
-         * NOTE: for now, we do not provide any readv()/writev() methods
-         *       because they are messy to implement and they are not
-         *       used to a great extent anyway.
-         */
         concat->mtd.erase = concat_erase;
         concat->mtd.read = concat_read;
         concat->mtd.write = concat_write;