/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef	_SYS_GNTTAB_H
#define	_SYS_GNTTAB_H

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * gnttab.h
 *
 * Two sets of functionality:
 * 1. Granting foreign access to our memory reservation.
 * 2. Accessing others' memory reservations via grant references.
 * (i.e., mechanisms for both sender and recipient of grant references)
 *
 * Copyright (c) 2004-2005, K A Fraser
 * Copyright (c) 2005, Christopher Clark
 *
 * This file may be distributed separately from the Linux kernel, or
 * incorporated into other software packages, subject to the following license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <sys/hypervisor.h>
#include <xen/public/grant_table.h>

#ifdef __cplusplus
extern "C" {
#endif

/* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
#ifdef __ia64__
#define	NR_GRANT_FRAMES 1
#else
#define	NR_GRANT_FRAMES 4
#endif

struct gnttab_free_callback {
	struct gnttab_free_callback *next;
	void (*fn)(void *);
	void *arg;
	uint16_t count;
};

/*
 * For i86xpv the "frames" in grant table terminology are really MFNs.
 */
typedef mfn_t gnttab_frame_t;
#define	FRAME_TO_MA(f)	((maddr_t)(f) << PAGESHIFT)

int gnttab_grant_foreign_access(domid_t, gnttab_frame_t, int readonly);

/*
 * End access through the given grant reference, iff the grant entry is no
 * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
 * use.
 */
int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);

/*
 * Eventually end access through the given grant reference, and once that
 * access has been ended, free the given page too.  Access will be ended
 * immediately iff the grant entry is not in use, otherwise it will happen
 * some time later.  page may be 0, in which case no freeing will occur.
 */
void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
	gnttab_frame_t page);

int gnttab_grant_foreign_transfer(domid_t domid);

gnttab_frame_t gnttab_end_foreign_transfer_ref(grant_ref_t ref);
gnttab_frame_t gnttab_end_foreign_transfer(grant_ref_t ref);

int gnttab_query_foreign_access(grant_ref_t ref);

/*
 * operations on reserved batches of grant references
 */
int gnttab_alloc_grant_references(uint16_t count, grant_ref_t *pprivate_head);

void gnttab_free_grant_reference(grant_ref_t ref);

void gnttab_free_grant_references(grant_ref_t head);

int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);

void gnttab_release_grant_reference(grant_ref_t *private_head,
	grant_ref_t release);

void gnttab_request_free_callback(struct gnttab_free_callback *callback,
	void (*fn)(void *), void *arg, uint16_t count);

void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
	gnttab_frame_t frame, int readonly);

void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid);

#define	gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))

/*
 * framework
 */
void gnttab_init(void);
void gnttab_suspend(void);
void gnttab_resume(void);

#ifdef	__cplusplus
}
#endif

#endif /* _SYS_GNTTAB_H */