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authorJens Wiklander <jens.wiklander@linaro.org>2021-06-15 22:23:54 +0200
committerJens Wiklander <jens.wiklander@linaro.org>2021-11-17 14:08:57 +0100
commit6749e69c4dadd352bdfdb306513aa48cc15fbdd6 (patch)
treeeb89ef076b0ec295b78866d6f7f7225e7df1007d /drivers/tee/optee/optee_msg.h
parent787c80cc7b22804aa370f04a19f9fe0fa98b1e49 (diff)
optee: add asynchronous notifications
Adds support for asynchronous notifications from secure world to normal world. This allows a design with a top half and bottom half type of driver where the top half runs in secure interrupt context and a notifications tells normal world to schedule a yielding call to do the bottom half processing. The protocol is defined in optee_msg.h optee_rpc_cmd.h and optee_smc.h. A notification consists of a 32-bit value which normal world can retrieve using a fastcall into secure world. The value OPTEE_SMC_ASYNC_NOTIF_VALUE_DO_BOTTOM_HALF (0) has a special meaning. When this value is sent it means that normal world is supposed to make a yielding call OPTEE_MSG_CMD_DO_BOTTOM_HALF. Notification capability is negotiated while the driver is initialized. If both sides supports these notifications then they are enabled. An interrupt is used to notify the driver that there are asynchronous notifications pending. The maximum needed notification value is communicated at this stage. This allows scaling up when needed. Reviewed-by: Sumit Garg <sumit.garg@linaro.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'drivers/tee/optee/optee_msg.h')
-rw-r--r--drivers/tee/optee/optee_msg.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h
index 2422e185d400..70e9cc2ee96b 100644
--- a/drivers/tee/optee/optee_msg.h
+++ b/drivers/tee/optee/optee_msg.h
@@ -318,6 +318,13 @@ struct optee_msg_arg {
* [in] param[0].u.rmem.shm_ref holds shared memory reference
* [in] param[0].u.rmem.offs 0
* [in] param[0].u.rmem.size 0
+ *
+ * OPTEE_MSG_CMD_DO_BOTTOM_HALF does the scheduled bottom half processing
+ * of a driver.
+ *
+ * OPTEE_MSG_CMD_STOP_ASYNC_NOTIF informs secure world that from now is
+ * normal world unable to process asynchronous notifications. Typically
+ * used when the driver is shut down.
*/
#define OPTEE_MSG_CMD_OPEN_SESSION 0
#define OPTEE_MSG_CMD_INVOKE_COMMAND 1
@@ -325,6 +332,8 @@ struct optee_msg_arg {
#define OPTEE_MSG_CMD_CANCEL 3
#define OPTEE_MSG_CMD_REGISTER_SHM 4
#define OPTEE_MSG_CMD_UNREGISTER_SHM 5
+#define OPTEE_MSG_CMD_DO_BOTTOM_HALF 6
+#define OPTEE_MSG_CMD_STOP_ASYNC_NOTIF 7
#define OPTEE_MSG_FUNCID_CALL_WITH_ARG 0x0004
#endif /* _OPTEE_MSG_H */