From: Greg Joyce <redacted>

Add read and write functions that allow SED Opal keys to stored
in a permanent keystore.

Signed-off-by: Greg Joyce <redacted>
Reviewed-by: Jonathan Derrick <jonathan.derrick@linux.dev>
---
 block/Makefile               |  2 +-
 block/sed-opal-key.c         | 24 ++++++++++++++++++++++++
 include/linux/sed-opal-key.h | 15 +++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 block/sed-opal-key.c
 create mode 100644 include/linux/sed-opal-key.h

diff --git a/block/Makefile b/block/Makefile
index 46ada9dc8bbf..ea07d80402a6 100644
--- a/block/Makefile
+++ b/block/Makefile

@@ -34,7 +34,7 @@ obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
 obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
-obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
+obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o sed-opal-key.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
 obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o \
 					   blk-crypto-sysfs.o

diff --git a/block/sed-opal-key.c b/block/sed-opal-key.c
new file mode 100644
index 000000000000..16f380164c44
--- /dev/null
+++ b/block/sed-opal-key.c

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SED key operations.
+ *
+ * Copyright (C) 2022 IBM Corporation
+ *
+ * These are the accessor functions (read/write) for SED Opal
+ * keys. Specific keystores can provide overrides.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/sed-opal-key.h>
+
+int __weak sed_read_key(char *keyname, char *key, u_int *keylen)
+{
+	return -EOPNOTSUPP;
+}
+
+int __weak sed_write_key(char *keyname, char *key, u_int keylen)
+{
+	return -EOPNOTSUPP;
+}