mtd: introduce mtd_has_oob helper

We are working in the direction of making sure that MTD clients to not
use 'mtd->func' pointers directly. In some places we want to know if
OOB operations are supported by an MTD device. Introduce 'mtd_has_oob()'
helper for these purposes.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

3 files changed, 8 insertions, 3 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 83b0c82e9c94..c501eec17b38 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -1004,7 +1004,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
                         break;
 
                 case MTD_FILE_MODE_RAW:
-                        if (!mtd->read_oob || !mtd->write_oob)
+                        if (!mtd_has_oob(mtd))
                                 return -EOPNOTSUPP;
                         mfi->mode = arg;
 
diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c
index 4ec2af7fb845..072ed5970e2f 100644
--- a/drivers/mtd/sm_ftl.c
+++ b/drivers/mtd/sm_ftl.c
@@ -645,8 +645,8 @@ int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd)
         if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE)
                 return -ENODEV;
 
-        /* We use these functions for IO */
-        if (!mtd->read_oob || !mtd->write_oob)
+        /* We use OOB */
+        if (!mtd_has_oob(mtd))
                 return -ENODEV;
 
         /* Find geometry information */
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index f0dd5a305b89..478701566ba7 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -454,6 +454,11 @@ static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
         return do_div(sz, mtd->writesize);
 }
 
+static inline int mtd_has_oob(const struct mtd_info *mtd)
+{
+        return mtd->read_oob && mtd->write_oob;
+}
+
         /* Kernel-side ioctl definitions */
 
 struct mtd_partition;