/*
 * Copyright (c) 2013 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#ifdef	XNU_KERNEL_PRIVATE

#ifndef _VM_VM_COMPRESSOR_PAGER_H_
#define _VM_VM_COMPRESSOR_PAGER_H_

#include <mach/mach_types.h>
#include <kern/kern_types.h>
#include <vm/vm_external.h>

extern kern_return_t vm_compressor_pager_put(
	memory_object_t			mem_obj,
	memory_object_offset_t		offset,
	ppnum_t				ppnum,
	void				**current_chead,
	char				*scratch_buf,
	int				*compressed_count_delta_p);
extern kern_return_t vm_compressor_pager_get(
	memory_object_t		mem_obj,
	memory_object_offset_t	offset,
	ppnum_t			ppnum,
	int			*my_fault_type,
	int			flags,
	int			*compressed_count_delta_p);

#define	C_DONT_BLOCK		0x01
#define C_KEEP			0x02

extern unsigned int vm_compressor_pager_state_clr(
	memory_object_t		mem_obj,
	memory_object_offset_t	offset);
extern vm_external_state_t vm_compressor_pager_state_get(
	memory_object_t		mem_obj,
	memory_object_offset_t	offset);

#define VM_COMPRESSOR_PAGER_STATE_GET(object, offset)			\
	(((COMPRESSED_PAGER_IS_ACTIVE ||				\
	   DEFAULT_FREEZER_COMPRESSED_PAGER_IS_ACTIVE) &&		\
	  (object)->internal &&						\
	  (object)->pager != NULL &&					\
	  !(object)->terminating &&					\
	  (object)->alive)						\
	 ? vm_compressor_pager_state_get((object)->pager,		\
					 (offset) + (object)->paging_offset) \
	 : VM_EXTERNAL_STATE_UNKNOWN)

#define VM_COMPRESSOR_PAGER_STATE_CLR(object, offset)			\
	MACRO_BEGIN							\
	if ((COMPRESSED_PAGER_IS_ACTIVE ||				\
	     DEFAULT_FREEZER_COMPRESSED_PAGER_IS_ACTIVE) &&		\
	    (object)->internal &&					\
	    (object)->pager != NULL &&					\
	    !(object)->terminating &&					\
	    (object)->alive) {						\
		int _num_pages_cleared;					\
		_num_pages_cleared =					\
			vm_compressor_pager_state_clr(			\
				(object)->pager,			\
				(offset) + (object)->paging_offset);	\
		if (_num_pages_cleared) {				\
			vm_compressor_pager_count((object)->pager,	\
						  -_num_pages_cleared,	\
						  FALSE, /* shared */	\
						  (object));		\
		}							\
		if (_num_pages_cleared &&				\
		    (object)->purgable != VM_PURGABLE_DENY &&		\
		    (object)->vo_purgeable_owner != NULL) {		\
			/* less compressed purgeable pages */		\
			assert(_num_pages_cleared == 1);		\
			vm_purgeable_compressed_update(			\
				(object),				\
				-_num_pages_cleared);			\
		}							\
	}								\
	MACRO_END

extern void vm_compressor_pager_transfer(
	memory_object_t		dst_mem_obj,
	memory_object_offset_t	dst_offset,
	memory_object_t		src_mem_obj,
	memory_object_offset_t	src_offset);
extern memory_object_offset_t vm_compressor_pager_next_compressed(
	memory_object_t		mem_obj,
	memory_object_offset_t	offset);

extern void vm_compressor_init(void);
extern int vm_compressor_put(ppnum_t pn, int *slot, void **current_chead, char *scratch_buf);
extern int vm_compressor_get(ppnum_t pn, int *slot, int flags);
extern int vm_compressor_free(int *slot, int flags);
extern unsigned int vm_compressor_pager_reap_pages(memory_object_t mem_obj, int flags);
extern unsigned int vm_compressor_pager_get_slots_occupied(memory_object_t mem_obj);
extern unsigned int vm_compressor_pager_get_count(memory_object_t mem_obj);
extern void vm_compressor_pager_count(memory_object_t mem_obj,
				      int compressed_count_delta,
				      boolean_t shared_lock,
				      vm_object_t object);
extern void vm_compressor_transfer(int *dst_slot_p, int	*src_slot_p);

#endif	/* _VM_VM_COMPRESSOR_PAGER_H_ */

#endif	/* XNU_KERNEL_PRIVATE */