tee: change return code for REE FS supplicant cmd

If OP-TEE core is compiled with support of REE FS and RPMB at the same time (CFG_RPMB_FS ?= y; CFG_RPMB_FS ?= y), and persistent storage API is used with TEE_STORAGE_PRIVATE storage id, it will lead to TA panic.

E/TC:? 0 TA panicked with code 0xffff0009
.....
E/TC:? 0 Call stack:
E/TC:? 0 0x000000004002f2f8 TEE_OpenPersistentObject at lib/libutee/tee_api_objects.c:422

In this particular case TEE_ERROR_STORAGE_NOT_AVAILABLE is more suitable than TEE_ERROR_NOT_IMPLEMENTED, as it provides to a TA a possibility to handle this error code [1].

From GPD TEE Internal Core specification [2]:
TEE_ERROR_STORAGE_NOT_AVAILABLE - if the persistent object is stored in a storage area which is currently inaccessible. It may be associated with the device but unplugged, busy, or inaccessible for some other reason.

[1]: https://github.com/OP-TEE/optee_os/blob/94db01ef448d1e552161c2d861d57a5f8bda0cc0/lib/libutee/tee_api_objects.c#L419
[2]: https://globalplatform.org/wp-content/uploads/2018/06/GPD_TEE_Internal_Core_API_Specification_v1.1.2.50_PublicReview.pdf

Signed-off-by Igor Opaniuk <[email protected]>

---
 drivers/tee/optee/supplicant.c | 4 ++--
 include/tee.h                  | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

drivers/tee/optee/supplicant.c +2 -2

index b1ea65b..c5726ec 100644
@@ -82,8 +82,8 @@ void optee_suppl_cmd(struct udevice *dev, struct tee_shm *shm_arg,
                cmd_shm_free(arg);
                break;
        case OPTEE_MSG_RPC_CMD_FS:
-               debug("OPTEE_MSG_RPC_CMD_FS not implemented\n");
-               arg->ret = TEE_ERROR_NOT_IMPLEMENTED;
+               debug("REE FS storage isn't available\n");
+               arg->ret = TEE_ERROR_STORAGE_NOT_AVAILABLE;
                break;
        case OPTEE_MSG_RPC_CMD_RPMB:
                optee_suppl_cmd_rpmb(dev, arg);

include/tee.h +1 -1

index 98b1c9c..edd9f9b 100644
@@ -34,6 +34,7 @@
  * struct tee_version_data::gen_caps
  */
 #define TEE_SUCCESS                    0x00000000
+#define TEE_ERROR_STORAGE_NOT_AVAILABLE        0xf0100003
 #define TEE_ERROR_GENERIC              0xffff0000
 #define TEE_ERROR_BAD_PARAMETERS       0xffff0006
 #define TEE_ERROR_ITEM_NOT_FOUND       0xffff0008
--

2.7.4

If OP-TEE core is compiled with support of REE FS and RPMB at the same time (CFG_RPMB_FS ?= y; CFG_RPMB_FS ?= y), and persistent storage API is used with TEE_STORAGE_PRIVATE storage id, it will lead to TA panic.

E/TC:? 0 TA panicked with code 0xffff0009
.....
E/TC:? 0 Call stack:
E/TC:? 0 0x000000004002f2f8 TEE_OpenPersistentObject at lib/libutee/tee_api_objects.c:422

In this particular case TEE_ERROR_STORAGE_NOT_AVAILABLE is more suitable than TEE_ERROR_NOT_IMPLEMENTED, as it provides to a TA a possibility to handle this error code [1].

Quoted 1 line

From GPD TEE Internal Core specification [2]:

TEE_ERROR_STORAGE_NOT_AVAILABLE - if the persistent object is stored in a storage area which is currently inaccessible. It may be associated with the device but unplugged, busy, or inaccessible for some other reason.

[1]: https://github.com/OP-TEE/optee_os/blob/94db01ef448d1e552161c2d861d57a5f8bda0cc0/lib/libutee/tee_api_objects.c#L419
[2]: https://globalplatform.org/wp-content/uploads/2018/06/GPD_TEE_Internal_Core_API_Specification_v1.1.2.50_PublicReview.pdf

Signed-off-by Igor Opaniuk <[email protected]>

Reviewed-by Jens Wiklander <[email protected]>