mtd: add a flags for partitions which should just leave smth. after them

Add support for MTDPART_OFS_RETAIN: such partitions start at the current
offset, take as much space as possible, but rain part->size bytes after
the end of the partitions for other parts. Primarily this is intended
for ts72xx arm platforms cleanup.

Artem: tweaked the patch a bit

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 3477e16be1c8..b73720502433 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -479,6 +479,19 @@ static struct mtd_part *allocate_partition(struct mtd_info *master,
                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
                 }
         }
+        if (slave->offset == MTDPART_OFS_RETAIN) {
+                slave->offset = cur_offset;
+                if (master->size - slave->offset >= slave->mtd.size) {
+                        slave->mtd.size = master->size - slave->offset
+                                                        - slave->mtd.size;
+                } else {
+                        printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
+                                part->name, master->size - slave->offset,
+                                slave->mtd.size);
+                        /* register to preserve ordering */
+                        goto out_register;
+                }
+        }
         if (slave->mtd.size == MTDPART_SIZ_FULL)
                 slave->mtd.size = master->size - slave->offset;