[PATCH 1/2] powerpc/powernv: add OPAL APIs for secure variables

[Nayna Jain <nayna@linux.ibm.com>]

From: Claudio Carvalho <cclaudio@linux.ibm.com>

The X.509 certificates trusted by the platform and other information
required to secure boot the OS kernel are wrapped in secure variables,
which are controlled by OPAL. These variables are manipulated by
userspace tools using filesystem interface. This patch adds support
for the OPAL APIs required to expose variables to userspace.

OPAL_SECVAR_GET_NEXT:
For a given secure variable, it returns the name and vendor GUID
of the next variable.

OPAL_SECVAR_ENQUEUE_UPDATE:
Enqueue the supplied secure variable update so that it can be processed
by OPAL in the next boot. Variable updates cannot be be processed right
away because the variable storage is write locked at runtime.

OPAL_SECVAR_GET_SIZE:
Returns size information about the variable.

Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
---
 arch/powerpc/include/asm/opal-api.h          |  3 +
 arch/powerpc/include/asm/opal-secvar.h       |  9 +++
 arch/powerpc/include/asm/opal.h              |  8 +++
 arch/powerpc/platforms/powernv/opal-call.c   |  3 +
 arch/powerpc/platforms/powernv/opal-secvar.c | 60 +++++++++++++++++++-
 5 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index a505e669b4b6..fa3083966efc 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -213,6 +213,9 @@
 #define	OPAL_NX_COPROC_INIT			167
 #define OPAL_XIVE_GET_VP_STATE			170
 #define OPAL_SECVAR_GET                         173
+#define OPAL_SECVAR_GET_SIZE                    174
+#define OPAL_SECVAR_GET_NEXT                    175
+#define OPAL_SECVAR_ENQUEUE_UPDATE              176
 #define OPAL_SECVAR_BACKEND                     177
 #define OPAL_LAST				177
 
diff --git a/arch/powerpc/include/asm/opal-secvar.h b/arch/powerpc/include/asm/opal-secvar.h
index b677171a0368..26ebbc63dd70 100644
--- a/arch/powerpc/include/asm/opal-secvar.h
+++ b/arch/powerpc/include/asm/opal-secvar.h
@@ -20,4 +20,13 @@ extern int opal_get_variable(u8 *key, unsigned long ksize,
 
 extern int opal_variable_version(unsigned long *backend);
 
+extern int opal_get_variable_size(u8 *key, unsigned long ksize,
+				  unsigned long *mdsize, unsigned long *dsize);
+
+extern int opal_get_next_variable(u8 *key, unsigned long *keylen,
+				  unsigned long keysize);
+
+extern int opal_set_variable(u8 *key, unsigned long ksize, u8 *metadata,
+			     unsigned long mdsize, u8 *data,
+			     unsigned long dsize);
 #endif
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 57d2c2356eda..a6fcb59c91cc 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -399,6 +399,14 @@ extern int opal_secvar_get(uint64_t k_key, uint64_t k_key_len,
 			   uint64_t k_data, uint64_t k_data_size);
 
 extern int opal_secvar_backend(uint64_t k_backend);
+extern int opal_secvar_get_size(uint64_t k_key, uint64_t k_key_len,
+				uint64_t k_metadata_size, uint64_t k_data_size);
+extern int opal_secvar_get_next(uint64_t k_key, uint64_t k_key_len,
+				uint64_t k_key_size);
+extern int opal_secvar_enqueue_update(uint64_t k_key, uint64_t k_key_len,
+				      uint64_t k_metadata,
+				      uint64_t k_metadata_size,
+				      uint64_t k_data, uint64_t k_data_size);
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c
index 0445980f294f..dda3a4c5bb79 100644
--- a/arch/powerpc/platforms/powernv/opal-call.c
+++ b/arch/powerpc/platforms/powernv/opal-call.c
@@ -290,3 +290,6 @@ OPAL_CALL(opal_sensor_group_enable,		OPAL_SENSOR_GROUP_ENABLE);
 OPAL_CALL(opal_nx_coproc_init,			OPAL_NX_COPROC_INIT);
 OPAL_CALL(opal_secvar_get,                      OPAL_SECVAR_GET);
 OPAL_CALL(opal_secvar_backend,                  OPAL_SECVAR_BACKEND);
+OPAL_CALL(opal_secvar_get_size,                 OPAL_SECVAR_GET_SIZE);
+OPAL_CALL(opal_secvar_get_next,                 OPAL_SECVAR_GET_NEXT);
+OPAL_CALL(opal_secvar_enqueue_update,           OPAL_SECVAR_ENQUEUE_UPDATE);
diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c b/arch/powerpc/platforms/powernv/opal-secvar.c
index dba441dd5af1..afa67b87ad7a 100644
--- a/arch/powerpc/platforms/powernv/opal-secvar.c
+++ b/arch/powerpc/platforms/powernv/opal-secvar.c
@@ -30,7 +30,10 @@ static bool is_opal_secvar_supported(void)
 		return opal_secvar_supported;
 
 	if (!opal_check_token(OPAL_SECVAR_GET)
-	    || !opal_check_token(OPAL_SECVAR_BACKEND)) {
+	    || !opal_check_token(OPAL_SECVAR_BACKEND)
+	    || !opal_check_token(OPAL_SECVAR_GET_SIZE)
+	    || !opal_check_token(OPAL_SECVAR_GET_NEXT)
+	    || !opal_check_token(OPAL_SECVAR_ENQUEUE_UPDATE)) {
 		pr_err("OPAL doesn't support secure variables\n");
 		opal_secvar_supported = false;
 	} else {
@@ -83,3 +86,58 @@ int opal_variable_version(unsigned long *backend)
 
 	return rc;
 }
+
+int opal_get_variable_size(u8 *key, unsigned long ksize, unsigned long *mdsize,
+			   unsigned long *dsize)
+{
+	int rc;
+
+	if (!is_opal_secvar_supported())
+		return OPAL_UNSUPPORTED;
+
+	if (mdsize)
+		*mdsize = cpu_to_be64(*mdsize);
+	if (dsize)
+		*dsize = cpu_to_be64(*dsize);
+
+	rc = opal_secvar_get_size(__pa(key), ksize, __pa(mdsize), __pa(dsize));
+
+	if (mdsize)
+		*mdsize = be64_to_cpu(*mdsize);
+	if (dsize)
+		*dsize = be64_to_cpu(*dsize);
+	return rc;
+}
+
+int opal_get_next_variable(u8 *key, unsigned long *keylen,
+			   unsigned long keysize)
+{
+	int rc;
+
+	if (!is_opal_secvar_supported())
+		return OPAL_UNSUPPORTED;
+
+	if (!keylen)
+		return OPAL_PARAMETER;
+	*keylen = cpu_to_be64(*keylen);
+
+	rc = opal_secvar_get_next(__pa(key), __pa(keylen), keysize);
+
+	*keylen = be64_to_cpu(*keylen);
+
+	return rc;
+}
+
+int opal_set_variable(u8 *key, unsigned long ksize, u8 *metadata,
+		      unsigned long mdsize, u8 *data, unsigned long dsize)
+{
+	int rc;
+
+	if (!is_opal_secvar_supported())
+		return OPAL_UNSUPPORTED;
+
+	rc = opal_secvar_enqueue_update(__pa(key), ksize, __pa(metadata),
+			mdsize, __pa(data), dsize);
+
+	return rc;
+}
-- 
2.20.1