kernel: add channel/port ipc mechanism

kernel/port.c

@@ -0,0 +1,78 @@
+#include <kernel/channel.h>
+#include <kernel/port.h>
+#include <kernel/util.h>
+
+#define PORT_CAST(p) OBJECT_C_CAST(struct port, p_base, &port_type, p)
+
+static struct object_type port_type = {
+	.ob_name = "port",
+	.ob_size = sizeof(struct port),
+	.ob_header_offset = offsetof(struct port, p_base),
+};
+
+kern_status_t port_type_init(void)
+{
+	return object_type_register(&port_type);
+}
+
+struct port *port_cast(struct object *obj)
+{
+	return PORT_CAST(obj);
+}
+
+static void wait_for_reply(struct port *port)
+{
+}
+
+struct port *port_create(void)
+{
+	struct object *port_object = object_create(&port_type);
+	if (!port_object) {
+		return NULL;
+	}
+
+	struct port *port = PORT_CAST(port_object);
+
+	port->p_status = PORT_OFFLINE;
+
+	return port;
+}
+
+kern_status_t port_connect(struct port *port, struct channel *remote)
+{
+	if (port->p_status != PORT_OFFLINE) {
+		return KERN_BAD_STATE;
+	}
+
+	port->p_remote = remote;
+	port->p_status = PORT_READY;
+	return KERN_OK;
+}
+
+kern_status_t port_send_msg(
+	struct port *port,
+	const struct msg *req,
+	struct msg *resp)
+{
+	if (port->p_status != PORT_READY) {
+		return KERN_BAD_STATE;
+	}
+
+	struct thread *self = current_thread();
+	struct kmsg *msg = &self->tr_msg;
+	msg->msg_sender_thread = self;
+	msg->msg_sender_port = port;
+	msg->msg_req = req;
+	msg->msg_resp = resp;
+
+	unsigned long flags;
+	channel_lock_irqsave(port->p_remote, &flags);
+	channel_enqueue_msg(port->p_remote, msg);
+	channel_unlock_irqrestore(port->p_remote, flags);
+
+	port->p_status = PORT_SEND_BLOCKED;
+
+	wait_for_reply(port);
+
+	return msg->msg_result;
+}