path: root/lib/libmtd_int.h
diff options
authorArtem Bityutskiy <>2010-07-17 20:08:33 +0300
committerArtem Bityutskiy <>2010-07-26 08:37:00 +0300
commitf1e870c3e9a1a80be7a1d886d61ccac0f8e97e10 (patch)
tree6860d01fa73cba0bb5de6fcf4a19b7a2ac007e55 /lib/libmtd_int.h
parent05f56bf49ee0de8979c29c11f61a01e30e964444 (diff)
libmtd: support MEMERASE64
This patch is base on Kevin Cernekee's patch posted to the MTD mailing list. It adds MEMERASE64 support to the 'mtd_erase()' call. Now it first tries to use MEMERASE64, and if that is not supported, falls back to the old MEMERASE ioctl. This patch also introduces an 'offs64_ioctl' flag to the libmtd descriptor. However, we cannot initialize it in 'libmtd_open()', because we need an MTD device node, which we do not have in 'libmtd_open()'. Thus, we firs mark this flag as "uninitialized", and at the first invocation of 'mtd_erase()' we initialize it. This also means that we have to pass the limbtd descriptor to 'mtd_erase()', to save the flag value. This, in turn, requires tweaking 'mtd_erase()' users. This is not very nice, but good enough so far. Signed-off-by: Artem Bityutskiy <>
Diffstat (limited to 'lib/libmtd_int.h')
1 files changed, 18 insertions, 0 deletions
diff --git a/lib/libmtd_int.h b/lib/libmtd_int.h
index 7de4b42..bb48d35 100644
--- a/lib/libmtd_int.h
+++ b/lib/libmtd_int.h
@@ -43,6 +43,10 @@ extern "C" {
#define MTD_REGION_CNT "numeraseregions"
#define MTD_FLAGS "flags"
* libmtd - MTD library description data structure.
* @sysfs_mtd: MTD directory in sysfs
@@ -58,6 +62,19 @@ extern "C" {
* @mtd_region_cnt: count of additional erase regions file pattern
* @mtd_flags: MTD device flags file pattern
* @sysfs_supported: non-zero if sysfs is supported by MTD
+ * @offs64_ioctls: %OFFS64_IOCTLS_SUPPORTED if 64-bit %MEMERASE64,
+ * %MEMREADOOB64, %MEMWRITEOOB64 MTD device ioctls are
+ * supported, %OFFS64_IOCTLS_NOT_SUPPORTED if not, and
+ * %OFFS64_IOCTLS_UNKNOWN if it is not known yet;
+ *
+ * Note, we cannot find out whether 64-bit ioctls are supported by MTD when we
+ * are initializing the library, because this requires an MTD device node.
+ * Indeed, we have to actually call the ioctl and check for %ENOTTY to find
+ * out whether it is supported or not.
+ *
+ * Thus, we leave %offs64_ioctls uninitialized in 'libmtd_open()', and
+ * initialize it later, when corresponding libmtd function is used, and when
+ * we actually have a device node and can invoke an ioctl command on it.
struct libmtd
@@ -74,6 +91,7 @@ struct libmtd
char *mtd_region_cnt;
char *mtd_flags;
unsigned int sysfs_supported:1;
+ unsigned int offs64_ioctls:2;
int legacy_libmtd_open(void);