#ifndef KERNEL_VM_CONTROLLER_H_
#define KERNEL_VM_CONTROLLER_H_

#include <kernel/locks.h>
#include <kernel/object.h>
#include <mango/types.h>

struct thread;
struct equeue;
struct vm_object;

enum page_request_status {
	PAGE_REQUEST_PENDING = 0,
	PAGE_REQUEST_IN_PROGRESS,
	PAGE_REQUEST_COMPLETE,
};

struct vm_controller {
	struct object vc_base;
	/* tree of struct vm_objects bound to this controller, keyed with the
	 * equeue_key_t specified when the object(s) were created. */
	struct btree vc_objects;
	/* tree of pending page requests */
	struct btree vc_requests;
	/* the equeue to send async page requests to */
	struct equeue *vc_eq;
	equeue_key_t vc_eq_key;
	/* the number of page requests queued with status PAGE_REQUEST_PENDING.
	 * used to assert/clear VM_CONTROLLER_SIGNAL_REQUEST_RECEIVED */
	size_t vc_requests_waiting;
};

struct page_request {
	uint64_t req_id;
	unsigned int req_type;
	enum page_request_status req_status;
	kern_status_t req_result;
	spin_lock_t req_lock;
	struct vm_object *req_object;
	struct thread *req_sender;
	struct btree_node req_node;
	off_t req_offset;
	size_t req_length;
};

extern kern_status_t vm_controller_type_init(void);
extern struct vm_controller *vm_controller_cast(struct object *obj);

extern struct vm_controller *vm_controller_create(void);

extern kern_status_t vm_controller_recv(
	struct vm_controller *ctrl,
	equeue_packet_page_request_t *out);
extern kern_status_t vm_controller_recv_async(
	struct vm_controller *ctrl,
	struct equeue *eq,
	equeue_key_t key);

extern kern_status_t vm_controller_create_object(
	struct vm_controller *ctrl,
	const char *name,
	size_t name_len,
	equeue_key_t key,
	size_t data_len,
	vm_prot_t prot,
	struct vm_object **out);
extern kern_status_t vm_controller_detach_object(
	struct vm_controller *ctrl,
	struct vm_object *vmo);
extern kern_status_t vm_controller_supply_pages(
	struct vm_controller *ctrl,
	struct vm_object *dst,
	off_t dst_offset,
	struct vm_object *src,
	off_t src_offset,
	size_t count);

extern kern_status_t vm_controller_send_request(
	struct vm_controller *ctrl,
	struct page_request *req,
	unsigned long *irq_flags);

DEFINE_OBJECT_LOCK_FUNCTION(vm_controller, vc_base)

#endif