[PATCH 2/6] tee: Add kernel client object invoke helper

[Harshal Dev]

From: Amirreza Zarrabi <amirreza.zarrabi@xxxxxxxxxxxxxxxx>

Kernel clients can open a TEE context and invoke regular TA commands
through tee_client_invoke_func(). However, there is currently no
equivalent helper for invoking TEE objects.

Add tee_client_object_invoke_func() as a kernel client API for issuing
object invocation requests. The helper checks that the backend provides
object_invoke_func() before setting the MSB of the object-id and forwarding
the request. The MSB of the object-id informs the TEE backend that the
object is invoked from a kernel context.

This allows TEE backends that support privileged object-based calls from
the kernel-space.

Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@xxxxxxxxxxxxxxxx>
Signed-off-by: Harshal Dev <harshal.dev@xxxxxxxxxxxxxxxx>
---
 drivers/tee/tee_core.c  | 13 +++++++++++++
 include/linux/tee_drv.h | 13 +++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 7f986d7fb47f..0783802fd010 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -1413,6 +1413,19 @@ int tee_client_invoke_func(struct tee_context *ctx,
 }
 EXPORT_SYMBOL_GPL(tee_client_invoke_func);
 
+int tee_client_object_invoke_func(struct tee_context *ctx,
+				  struct tee_ioctl_object_invoke_arg *arg,
+				  struct tee_param *param)
+{
+	if (!ctx->teedev->desc->ops->object_invoke_func)
+		return -EINVAL;
+
+	/* Indicate that this object is being invoked from a kernel context. */
+	arg->id = arg->id | BIT(63);
+	return ctx->teedev->desc->ops->object_invoke_func(ctx, arg, param);
+}
+EXPORT_SYMBOL_GPL(tee_client_object_invoke_func);
+
 int tee_client_cancel_req(struct tee_context *ctx,
 			  struct tee_ioctl_cancel_arg *arg)
 {
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index e561a26f537a..ca99c6b747a8 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -283,6 +283,19 @@ int tee_client_invoke_func(struct tee_context *ctx,
 			   struct tee_ioctl_invoke_arg *arg,
 			   struct tee_param *param);
 
+/**
+ * tee_client_object_invoke_func() - Invoke a TEE object from kernel space
+ * @ctx:    TEE Context
+ * @arg:    Invoke arguments, see description of
+ *          struct tee_ioctl_object_invoke_arg
+ * @param:  Parameters for the object invocation
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int tee_client_object_invoke_func(struct tee_context *ctx,
+				  struct tee_ioctl_object_invoke_arg *arg,
+				  struct tee_param *param);
+
 /**
  * tee_client_cancel_req() - Request cancellation of the previous open-session
  * or invoke-command operations in a Trusted Application

-- 
2.34.1