[PATCH 6/7] usb-storage,uas: enable security commands for USB-attached storage

[Milan Broz <gmazyland@gmail.com>]

This patch enables security commands (currently mostly OPAL hardware
encryption) for UAS and usb-storage drivers.

The SCSI layer uses security commands for the initial OPAL support
check (discovery command) and for in-kernel sed-ioctl interface.

Some adapters support these commands, but firmware can be buggy or
implemented incorrectly; the patch also adds a new quirk IGNORE_OPAL
to disable security commands for particular devices.

If adapters do not implement needed commands (ATA-12 pass-thru),
the commands are rejected, and OPAL support remains disabled.
(This is how it already works if OPAL command is sent from userspace
directly, like in sedutils.)

Signed-off-by: Milan Broz <gmazyland@gmail.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 2 ++
 drivers/usb/storage/scsiglue.c                  | 4 ++++
 drivers/usb/storage/uas.c                       | 5 +++++
 drivers/usb/storage/usb.c                       | 5 ++++-
 include/linux/usb_usual.h                       | 2 ++
 5 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 0a1731a0f0ef..e3f072cbb833 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6885,6 +6885,8 @@
 				y = ALWAYS_SYNC (issue a SYNCHRONIZE_CACHE
 					even if the device claims no cache,
 					not on uas)
+				z = IGNORE_OPAL (the device security commands
+					(OPAL) are broken, do not enable them);
 			Example: quirks=0419:aaf5:rl,0421:0433:rc
 
 	user_debug=	[KNL,ARM]
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index c54e9805da53..ef93813a2049 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -209,6 +209,10 @@ static int slave_configure(struct scsi_device *sdev)
 		/* Do not attempt to use WRITE SAME */
 		sdev->no_write_same = 1;
 
+		/* Allow security commands (OPAL) passthrough */
+		if (!(us->fflags & US_FL_IGNORE_OPAL))
+			sdev->security_supported = 1;
+
 		/*
 		 * Some disks return the total number of blocks in response
 		 * to READ CAPACITY rather than the highest block number.
diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 8a1c4449dcc9..8967767d6753 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -865,6 +865,11 @@ static int uas_slave_configure(struct scsi_device *sdev)
 	/* Some disks cannot handle WRITE_SAME */
 	if (devinfo->flags & US_FL_NO_SAME)
 		sdev->no_write_same = 1;
+
+	/* Allow security commands (OPAL) passthrough */
+	if (!(devinfo->flags & US_FL_IGNORE_OPAL))
+		sdev->security_supported = 1;
+
 	/*
 	 * Some disks return the total number of blocks in response
 	 * to READ CAPACITY rather than the highest block number.
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index bb48ab1bd461..3facc80292d7 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -477,7 +477,7 @@ void usb_stor_adjust_quirks(struct usb_device *udev, u64 *fflags)
 			US_FL_INITIAL_READ10 | US_FL_WRITE_CACHE |
 			US_FL_NO_ATA_1X | US_FL_NO_REPORT_OPCODES |
 			US_FL_MAX_SECTORS_240 | US_FL_NO_REPORT_LUNS |
-			US_FL_ALWAYS_SYNC);
+			US_FL_ALWAYS_SYNC | US_FL_IGNORE_OPAL);
 
 	p = quirks;
 	while (*p) {
@@ -566,6 +566,9 @@ void usb_stor_adjust_quirks(struct usb_device *udev, u64 *fflags)
 		case 'y':
 			f |= US_FL_ALWAYS_SYNC;
 			break;
+		case 'z':
+			f |= US_FL_IGNORE_OPAL;
+			break;
 		/* Ignore unrecognized flag characters */
 		}
 	}
diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 712363c7a2e8..0181c94d7d91 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -88,6 +88,8 @@
 		/* Cannot handle WRITE_SAME */			\
 	US_FLAG(SENSE_AFTER_SYNC, 0x80000000)			\
 		/* Do REQUEST_SENSE after SYNCHRONIZE_CACHE */	\
+	US_FLAG(IGNORE_OPAL, 0x100000000)			\
+		/* Security commands (OPAL) are broken */	\
 
 #define US_FLAG(name, value)	US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };
-- 
2.42.0