static int optee_ffa_yielding_call()

in optee/ffa_abi.c [529:600]

• 50 lines of code
• 7 McCabe index (conditional complexity)

static int optee_ffa_yielding_call(struct tee_context *ctx,
				   struct ffa_send_direct_data *data,
				   struct optee_msg_arg *rpc_arg)
{
	struct optee *optee = tee_get_drvdata(ctx->teedev);
	const struct ffa_dev_ops *ffa_ops = optee->ffa.ffa_ops;
	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
	struct optee_call_waiter w;
	u32 cmd = data->data0;
	u32 w4 = data->data1;
	u32 w5 = data->data2;
	u32 w6 = data->data3;
	int rc;

	/* Initialize waiter */
	optee_cq_wait_init(&optee->call_queue, &w);
	while (true) {
		rc = ffa_ops->sync_send_receive(ffa_dev, data);
		if (rc)
			goto done;

		switch ((int)data->data0) {
		case TEEC_SUCCESS:
			break;
		case TEEC_ERROR_BUSY:
			if (cmd == OPTEE_FFA_YIELDING_CALL_RESUME) {
				rc = -EIO;
				goto done;
			}

			/*
			 * Out of threads in secure world, wait for a thread
			 * become available.
			 */
			optee_cq_wait_for_completion(&optee->call_queue, &w);
			data->data0 = cmd;
			data->data1 = w4;
			data->data2 = w5;
			data->data3 = w6;
			continue;
		default:
			rc = -EIO;
			goto done;
		}

		if (data->data1 == OPTEE_FFA_YIELDING_CALL_RETURN_DONE)
			goto done;

		/*
		 * OP-TEE has returned with a RPC request.
		 *
		 * Note that data->data4 (passed in register w7) is already
		 * filled in by ffa_ops->sync_send_receive() returning
		 * above.
		 */
		cond_resched();
		optee_handle_ffa_rpc(ctx, data->data1, rpc_arg);
		cmd = OPTEE_FFA_YIELDING_CALL_RESUME;
		data->data0 = cmd;
		data->data1 = 0;
		data->data2 = 0;
		data->data3 = 0;
	}
done:
	/*
	 * We're done with our thread in secure world, if there's any
	 * thread waiters wake up one.
	 */
	optee_cq_wait_final(&optee->call_queue, &w);

	return rc;
}