Merge tag 'tee-drv-async-supplicant-for-v4.16' of https://git.linaro.org/people/jens.wiklander/linux-tee into next/drivers

Pull "Enable async communication with tee supplicant" from Jens Wiklander:

This pull request enables asynchronous communication with TEE supplicant
by introducing meta parameters in the user space API. The meta
parameters can be used to tag requests with an id that can be matched
against an asynchronous response as is done here in the OP-TEE driver.

Asynchronous supplicant communication is needed by OP-TEE to implement
GlobalPlatforms TEE Sockets API Specification v1.0.1. The specification
is available at https://www.globalplatform.org/specificationsdevice.asp.

This change is backwards compatible allowing older supplicants to work
with newer kernels and vice versa.

* tag 'tee-drv-async-supplicant-for-v4.16' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  optee: support asynchronous supplicant requests
  tee: add TEE_IOCTL_PARAM_ATTR_META
  tee: add tee_param_is_memref() for driver use

include/uapi/linux/tee.h

@@ -154,6 +154,13 @@ struct tee_ioctl_buf_data {
  */
 #define TEE_IOCTL_PARAM_ATTR_TYPE_MASK		0xff
 
+/* Meta parameter carrying extra information about the message. */
+#define TEE_IOCTL_PARAM_ATTR_META		0x100
+
+/* Mask of all known attr bits */
+#define TEE_IOCTL_PARAM_ATTR_MASK \
+	(TEE_IOCTL_PARAM_ATTR_TYPE_MASK | TEE_IOCTL_PARAM_ATTR_META)
+
 /*
  * Matches TEEC_LOGIN_* in GP TEE Client API
  * Are only defined for GP compliant TEEs