From: Luca Boccassi <redacted>

Not every OPAL drive supports SUM (Single User Mode), so report this
information to userspace via the get-status ioctl so that we can adjust
the formatting options accordingly.
Tested on a kingston drive (which supports it) and a samsung one
(which does not).

Signed-off-by: Luca Boccassi <redacted>
---
 block/sed-opal.c              | 2 ++
 include/uapi/linux/sed-opal.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 463873f61e01..c320093c14f1 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c

@@ -487,6 +487,8 @@ static int opal_discovery0_end(struct opal_dev *dev)
                        break;
                case FC_SINGLEUSER:
                        single_user = check_sum(body->features);
+                       if (single_user)
+                               dev->flags |= OPAL_FL_SUM_SUPPORTED;
                        break;
                case FC_GEOMETRY:
                        check_geometry(dev, body);

diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h
index 1fed3c9294fc..d7a1524023db 100644
--- a/include/uapi/linux/sed-opal.h
+++ b/include/uapi/linux/sed-opal.h

@@ -144,6 +144,7 @@ struct opal_read_write_table {
 #define OPAL_FL_LOCKED                 0x00000008
 #define OPAL_FL_MBR_ENABLED            0x00000010
 #define OPAL_FL_MBR_DONE               0x00000020
+#define OPAL_FL_SUM_SUPPORTED          0x00000040

 struct opal_status {
        __u32 flags;