1ae115bc7Smrj /*
2ae115bc7Smrj * CDDL HEADER START
3ae115bc7Smrj *
4ae115bc7Smrj * The contents of this file are subject to the terms of the
5ae115bc7Smrj * Common Development and Distribution License (the "License").
6ae115bc7Smrj * You may not use this file except in compliance with the License.
7ae115bc7Smrj *
8ae115bc7Smrj * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9ae115bc7Smrj * or http://www.opensolaris.org/os/licensing.
10ae115bc7Smrj * See the License for the specific language governing permissions
11ae115bc7Smrj * and limitations under the License.
12ae115bc7Smrj *
13ae115bc7Smrj * When distributing Covered Code, include this CDDL HEADER in each
14ae115bc7Smrj * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15ae115bc7Smrj * If applicable, add the following below this CDDL HEADER, with the
16ae115bc7Smrj * fields enclosed by brackets "[]" replaced with your own identifying
17ae115bc7Smrj * information: Portions Copyright [yyyy] [name of copyright owner]
18ae115bc7Smrj *
19ae115bc7Smrj * CDDL HEADER END
20ae115bc7Smrj */
21ae115bc7Smrj
22ae115bc7Smrj /*
23*6eaf49dbSStan Studzinski * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
24ae115bc7Smrj * Use is subject to license terms.
25ae115bc7Smrj */
26ae115bc7Smrj
27ae115bc7Smrj #include <sys/hold_page.h>
28ae115bc7Smrj
29843e1988Sjohnlev #if defined(__xpv)
30843e1988Sjohnlev #include <sys/hypervisor.h>
31843e1988Sjohnlev #endif
32843e1988Sjohnlev
33ae115bc7Smrj int
plat_hold_page(pfn_t pfn,int lock,page_t ** pp_ret)34ae115bc7Smrj plat_hold_page(pfn_t pfn, int lock, page_t **pp_ret)
35ae115bc7Smrj {
36843e1988Sjohnlev page_t *pp = page_numtopp_nolock(pfn);
37843e1988Sjohnlev
38843e1988Sjohnlev if (pp == NULL)
39843e1988Sjohnlev return (PLAT_HOLD_FAIL);
40843e1988Sjohnlev
41*6eaf49dbSStan Studzinski #if !defined(__xpv)
42*6eaf49dbSStan Studzinski /*
43*6eaf49dbSStan Studzinski * Pages are locked SE_SHARED because some hypervisors
44*6eaf49dbSStan Studzinski * like xVM ESX reclaim Guest OS memory by locking
45*6eaf49dbSStan Studzinski * it SE_EXCL so we want to leave these pages alone.
46*6eaf49dbSStan Studzinski */
47*6eaf49dbSStan Studzinski if (lock == PLAT_HOLD_LOCK) {
48*6eaf49dbSStan Studzinski ASSERT(pp_ret != NULL);
49*6eaf49dbSStan Studzinski if (page_trylock(pp, SE_SHARED) == 0)
50*6eaf49dbSStan Studzinski return (PLAT_HOLD_FAIL);
51*6eaf49dbSStan Studzinski }
52*6eaf49dbSStan Studzinski #else /* __xpv */
53843e1988Sjohnlev if (lock == PLAT_HOLD_LOCK) {
54843e1988Sjohnlev ASSERT(pp_ret != NULL);
55843e1988Sjohnlev if (page_trylock(pp, SE_EXCL) == 0)
56843e1988Sjohnlev return (PLAT_HOLD_FAIL);
57843e1988Sjohnlev }
58843e1988Sjohnlev
59843e1988Sjohnlev if (mfn_list[pfn] == MFN_INVALID) {
60843e1988Sjohnlev /* We failed - release the lock if we grabbed it earlier */
61843e1988Sjohnlev if (lock == PLAT_HOLD_LOCK) {
62843e1988Sjohnlev page_unlock(pp);
63843e1988Sjohnlev }
64843e1988Sjohnlev return (PLAT_HOLD_FAIL);
65843e1988Sjohnlev }
66*6eaf49dbSStan Studzinski #endif /* __xpv */
67*6eaf49dbSStan Studzinski
68843e1988Sjohnlev if (lock == PLAT_HOLD_LOCK)
69843e1988Sjohnlev *pp_ret = pp;
70843e1988Sjohnlev
71ae115bc7Smrj return (PLAT_HOLD_OK);
72ae115bc7Smrj }
73ae115bc7Smrj
74ae115bc7Smrj void
plat_release_page(page_t * pp)75ae115bc7Smrj plat_release_page(page_t *pp)
76ae115bc7Smrj {
77843e1988Sjohnlev ASSERT((pp != NULL) && PAGE_LOCKED(pp));
78843e1988Sjohnlev page_unlock(pp);
79ae115bc7Smrj }
80