[PATCH 1/2] tee: optee: GET_OS_REVISION: document a2 as a build identifier

[Jerome Forissier]

In the OPTEE_SMC_CALL_GET_OS_REVISION request, the previously reserved
parameter a2 is now documented as being an optional build identifier
(such as an SCM revision or commit ID, for instance).

A new structure optee_smc_call_get_os_revision_result is introduced to
be used when querying the secure OS version, instead of re-using the
struct defined for OPTEE_SMC_CALLS_REVISION.

Signed-off-by: Jerome Forissier <jerome.forissier at linaro.org>
---
 drivers/tee/optee/optee_smc.h | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h
index 069c8e1429de..d0b67c65ea8f 100644
--- a/drivers/tee/optee/optee_smc.h
+++ b/drivers/tee/optee/optee_smc.h
@@ -112,12 +112,20 @@ struct optee_smc_calls_revision_result {
  * Trusted OS, not of the API.
  *
  * Returns revision in a0-1 in the same way as OPTEE_SMC_CALLS_REVISION
- * described above.
+ * described above. May optionally return a 32-bit build identifier in a2,
+ * with zero meaning unspecified.
  */
 #define OPTEE_SMC_FUNCID_GET_OS_REVISION OPTEE_MSG_FUNCID_GET_OS_REVISION
 #define OPTEE_SMC_CALL_GET_OS_REVISION \
 	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_OS_REVISION)
 
+struct optee_smc_call_get_os_revision_result {
+	unsigned long major;
+	unsigned long minor;
+	unsigned long build_id;
+	unsigned long reserved1;
+};
+
 /*
  * Call with struct optee_msg_arg as argument
  *
-- 
2.7.4