From: Greg Joyce <gjo...@linux.vnet.ibm.com>

Define operations for SED Opal to read/write keys
from POWER LPAR Platform KeyStore(PLPKS). This allows
non-volatile storage of SED Opal keys.

Signed-off-by: Greg Joyce <gjo...@linux.vnet.ibm.com>
Reviewed-by: Jonathan Derrick <jonathan.derr...@linux.dev>
---
 arch/powerpc/platforms/pseries/Makefile       |   1 +
 .../powerpc/platforms/pseries/plpks_sed_ops.c | 126 ++++++++++++++++++
 2 files changed, 127 insertions(+)
 create mode 100644 arch/powerpc/platforms/pseries/plpks_sed_ops.c

diff --git a/arch/powerpc/platforms/pseries/Makefile 
b/arch/powerpc/platforms/pseries/Makefile
index 53c3b91af2f7..4242aed0d5d3 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_PPC_SVM)         += svm.o
 obj-$(CONFIG_FA_DUMP)          += rtas-fadump.o
 obj-$(CONFIG_PSERIES_PLPKS)    += plpks.o
 obj-$(CONFIG_PPC_SECURE_BOOT)  += plpks-secvar.o
+obj-$(CONFIG_PSERIES_PLPKS_SED)        += plpks-sed.o
 obj-$(CONFIG_SUSPEND)          += suspend.o
 obj-$(CONFIG_PPC_VAS)          += vas.o vas-sysfs.o
 
diff --git a/arch/powerpc/platforms/pseries/plpks_sed_ops.c 
b/arch/powerpc/platforms/pseries/plpks_sed_ops.c
new file mode 100644
index 000000000000..086934b319a9
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/plpks_sed_ops.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * POWER Platform specific code for non-volatile SED key access
+ * Copyright (C) 2022 IBM Corporation
+ *
+ * Define operations for SED Opal to read/write keys
+ * from POWER LPAR Platform KeyStore(PLPKS).
+ *
+ * Self Encrypting Drives(SED) key storage using PLPKS
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/ioctl.h>
+#include <linux/sed-opal-key.h>
+#include "plpks.h"
+
+/*
+ * structure that contains all SED data
+ */
+struct plpks_sed_object_data {
+       u_char version;
+       u_char pad1[7];
+       u_long authority;
+       u_long range;
+       u_int  key_len;
+       u_char key[32];
+};
+
+#define PLPKS_PLATVAR_POLICY            WORLDREADABLE
+#define PLPKS_PLATVAR_OS_COMMON         4
+
+#define PLPKS_SED_OBJECT_DATA_V0        0
+#define PLPKS_SED_MANGLED_LABEL         "/default/pri"
+#define PLPKS_SED_COMPONENT             "sed-opal"
+#define PLPKS_SED_KEY                   "opal-boot-pin"
+
+/*
+ * authority is admin1 and range is global
+ */
+#define PLPKS_SED_AUTHORITY  0x0000000900010001
+#define PLPKS_SED_RANGE      0x0000080200000001
+
+void plpks_init_var(struct plpks_var *var, char *keyname)
+{
+       var->name = keyname;
+       var->namelen = strlen(keyname);
+       if (strcmp(PLPKS_SED_KEY, keyname) == 0) {
+               var->name = PLPKS_SED_MANGLED_LABEL;
+               var->namelen = strlen(keyname);
+       }
+       var->policy = PLPKS_PLATVAR_POLICY;
+       var->os = PLPKS_PLATVAR_OS_COMMON;
+       var->data = NULL;
+       var->datalen = 0;
+       var->component = PLPKS_SED_COMPONENT;
+}
+
+/*
+ * Read the SED Opal key from PLPKS given the label
+ */
+int sed_read_key(char *keyname, char *key, u_int *keylen)
+{
+       struct plpks_var var;
+       struct plpks_sed_object_data data;
+       u_int offset;
+       int ret;
+       u_int len;
+
+       plpks_init_var(&var, keyname);
+       var.data = &data;
+       var.datalen = sizeof(data);
+
+       ret = plpks_read_os_var(&var);
+       if (ret != 0)
+               return ret;
+
+       offset = offsetof(struct plpks_sed_object_data, key);
+       if (offset > var.datalen) {
+               return -EINVAL;
+       }
+
+       len = min(be32_to_cpu(data.key_len), *keylen);
+
+       memcpy(key, data.key, len);
+       kfree(var.data);
+
+       key[len] = '\0';
+       *keylen = len;
+
+       return 0;
+}
+
+/*
+ * Write the SED Opal key to PLPKS given the label
+ */
+int sed_write_key(char *keyname, char *key, u_int keylen)
+{
+       struct plpks_var var;
+       struct plpks_sed_object_data data;
+       struct plpks_var_name vname;
+
+       plpks_init_var(&var, keyname);
+
+       var.datalen = sizeof(struct plpks_sed_object_data);
+       var.data = (u8 *)&data;
+
+       /* initialize SED object */
+       data.version = PLPKS_SED_OBJECT_DATA_V0;
+       data.authority = cpu_to_be64(PLPKS_SED_AUTHORITY);
+       data.range = cpu_to_be64(PLPKS_SED_RANGE);
+       memset(&data.pad1, '\0', sizeof(data.pad1));
+       data.key_len = cpu_to_be32(keylen);
+       memcpy(data.key, (char *)key, keylen);
+
+       /*
+        * Key update requires remove first. The return value
+        * is ignored since it's okay if the key doesn't exist.
+        */
+       vname.namelen = var.namelen;
+       vname.name = var.name;
+       plpks_remove_var(var.component, var.os, vname);
+
+       return plpks_write_var(var);
+}
-- 
gjo...@linux.vnet.ibm.com

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