optee: support asynchronous supplicant requests

Adds support for asynchronous supplicant requests, meaning that the
supplicant can process several requests in parallel or block in a
request for some time.
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>
Tested-by: Etienne Carriere <etienne.carriere@linaro.org> (b2260 pager=y/n)
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

drivers/tee/optee/core.c

@@ -187,12 +187,12 @@ static int optee_open(struct tee_context *ctx)
 	if (teedev == optee->supp_teedev) {
 		bool busy = true;
 
-		mutex_lock(&optee->supp.ctx_mutex);
+		mutex_lock(&optee->supp.mutex);
 		if (!optee->supp.ctx) {
 			busy = false;
 			optee->supp.ctx = ctx;
 		}
-		mutex_unlock(&optee->supp.ctx_mutex);
+		mutex_unlock(&optee->supp.mutex);
 		if (busy) {
 			kfree(ctxdata);
 			return -EBUSY;
@@ -252,11 +252,8 @@ static void optee_release(struct tee_context *ctx)
 
 	ctx->data = NULL;
 
-	if (teedev == optee->supp_teedev) {
-		mutex_lock(&optee->supp.ctx_mutex);
-		optee->supp.ctx = NULL;
-		mutex_unlock(&optee->supp.ctx_mutex);
-	}
+	if (teedev == optee->supp_teedev)
+		optee_supp_release(&optee->supp);
 }
 
 static const struct tee_driver_ops optee_ops = {

drivers/tee/optee/optee_private.h

@@ -53,36 +53,24 @@ struct optee_wait_queue {
  * @ctx			the context of current connected supplicant.
  *			if !NULL the supplicant device is available for use,
  *			else busy
- * @ctx_mutex:		held while accessing @ctx
- * @func:		supplicant function id to call
- * @ret:		call return value
- * @num_params:		number of elements in @param
- * @param:		parameters for @func
- * @req_posted:		if true, a request has been posted to the supplicant
- * @supp_next_send:	if true, next step is for supplicant to send response
- * @thrd_mutex:		held by the thread doing a request to supplicant
- * @supp_mutex:		held by supplicant while operating on this struct
- * @data_to_supp:	supplicant is waiting on this for next request
- * @data_from_supp:	requesting thread is waiting on this to get the result
+ * @mutex:		held while accessing content of this struct
+ * @req_id:		current request id if supplicant is doing synchronous
+ *			communication, else -1
+ * @reqs:		queued request not yet retrieved by supplicant
+ * @idr:		IDR holding all requests currently being processed
+ *			by supplicant
+ * @reqs_c:		completion used by supplicant when waiting for a
+ *			request to be queued.
  */
 struct optee_supp {
+	/* Serializes access to this struct */
+	struct mutex mutex;
 	struct tee_context *ctx;
-	/* Serializes access of ctx */
-	struct mutex ctx_mutex;
-
-	u32 func;
-	u32 ret;
-	size_t num_params;
-	struct tee_param *param;
-
-	bool req_posted;
-	bool supp_next_send;
-	/* Serializes access to this struct for requesting thread */
-	struct mutex thrd_mutex;
-	/* Serializes access to this struct for supplicant threads */
-	struct mutex supp_mutex;
-	struct completion data_to_supp;
-	struct completion data_from_supp;
+
+	int req_id;
+	struct list_head reqs;
+	struct idr idr;
+	struct completion reqs_c;
 };
 
 /**
@@ -142,6 +130,7 @@ int optee_supp_read(struct tee_context *ctx, void __user *buf, size_t len);
 int optee_supp_write(struct tee_context *ctx, void __user *buf, size_t len);
 void optee_supp_init(struct optee_supp *supp);
 void optee_supp_uninit(struct optee_supp *supp);
+void optee_supp_release(struct optee_supp *supp);
 
 int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
 		    struct tee_param *param);

drivers/tee/optee/rpc.c

@@ -192,10 +192,10 @@ static struct tee_shm *cmd_alloc_suppl(struct tee_context *ctx, size_t sz)
 	if (ret)
 		return ERR_PTR(-ENOMEM);
 
-	mutex_lock(&optee->supp.ctx_mutex);
+	mutex_lock(&optee->supp.mutex);
 	/* Increases count as secure world doesn't have a reference */
 	shm = tee_shm_get_from_id(optee->supp.ctx, param.u.value.c);
-	mutex_unlock(&optee->supp.ctx_mutex);
+	mutex_unlock(&optee->supp.mutex);
 	return shm;
 }