1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include <sys/hold_page.h> 28 29 #if defined(__xpv) 30 #include <sys/hypervisor.h> 31 #endif 32 33 int 34 plat_hold_page(pfn_t pfn, int lock, page_t **pp_ret) 35 { 36 page_t *pp = page_numtopp_nolock(pfn); 37 38 if (pp == NULL) 39 return (PLAT_HOLD_FAIL); 40 41 #if !defined(__xpv) 42 /* 43 * Pages are locked SE_SHARED because some hypervisors 44 * like xVM ESX reclaim Guest OS memory by locking 45 * it SE_EXCL so we want to leave these pages alone. 46 */ 47 if (lock == PLAT_HOLD_LOCK) { 48 ASSERT(pp_ret != NULL); 49 if (page_trylock(pp, SE_SHARED) == 0) 50 return (PLAT_HOLD_FAIL); 51 } 52 #else /* __xpv */ 53 if (lock == PLAT_HOLD_LOCK) { 54 ASSERT(pp_ret != NULL); 55 if (page_trylock(pp, SE_EXCL) == 0) 56 return (PLAT_HOLD_FAIL); 57 } 58 59 if (mfn_list[pfn] == MFN_INVALID) { 60 /* We failed - release the lock if we grabbed it earlier */ 61 if (lock == PLAT_HOLD_LOCK) { 62 page_unlock(pp); 63 } 64 return (PLAT_HOLD_FAIL); 65 } 66 #endif /* __xpv */ 67 68 if (lock == PLAT_HOLD_LOCK) 69 *pp_ret = pp; 70 71 return (PLAT_HOLD_OK); 72 } 73 74 void 75 plat_release_page(page_t *pp) 76 { 77 ASSERT((pp != NULL) && PAGE_LOCKED(pp)); 78 page_unlock(pp); 79 } 80