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      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  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
     27 /*	  All Rights Reserved  	*/
     28 
     29 /*
     30  * University Copyright- Copyright (c) 1982, 1986, 1988
     31  * The Regents of the University of California
     32  * All Rights Reserved
     33  *
     34  * University Acknowledgment- Portions of this document are derived from
     35  * software developed by the University of California, Berkeley, and its
     36  * contributors.
     37  */
     38 
     39 #ifndef	_VM_SEG_VN_H
     40 #define	_VM_SEG_VN_H
     41 
     42 #pragma ident	"@(#)seg_vn.h	1.62	07/08/15 SMI"
     43 
     44 #include <sys/lgrp.h>
     45 #include <vm/anon.h>
     46 
     47 #ifdef	__cplusplus
     48 extern "C" {
     49 #endif
     50 
     51 /*
     52  * A pointer to this structure is passed to segvn_create().
     53  */
     54 typedef struct segvn_crargs {
     55 	struct	vnode *vp;	/* vnode mapped from */
     56 	struct	cred *cred;	/* credentials */
     57 	u_offset_t	offset; /* starting offset of vnode for mapping */
     58 	uchar_t	type;		/* type of sharing done */
     59 	uchar_t	prot;		/* protections */
     60 	uchar_t	maxprot;	/* maximum protections */
     61 	uint_t	flags;		/* flags */
     62 	struct	anon_map *amp;	/* anon mapping to map to */
     63 	uint_t	szc;		/* max preferred page size code */
     64 	uint_t	lgrp_mem_policy_flags;
     65 } segvn_crargs_t;
     66 
     67 /*
     68  * (Semi) private data maintained by the seg_vn driver per segment mapping.
     69  *
     70  * The read/write segment lock protects all of segvn_data including the
     71  * vpage array.  All fields in segvn_data are treated as read-only when
     72  * the "read" version of the address space and the segment locks are held.
     73  * The "write" version of the segment lock, however, is required in order to
     74  * update the following fields:
     75  *
     76  *	pageprot
     77  *	prot
     78  *	amp
     79  *	vpage
     80  *
     81  * 	softlockcnt
     82  * is written by acquiring either the readers lock on the segment and
     83  * freemem lock, or any lock combination which guarantees exclusive use
     84  * of this segment (e.g., adress space writers lock,
     85  * address space readers lock + segment writers lock).
     86  */
     87 typedef struct	segvn_data {
     88 	krwlock_t lock;		/* protect segvn_data and vpage array */
     89 	kmutex_t segp_slock;	/* serialize insertions into seg_pcache */
     90 	uchar_t	pageprot;	/* true if per page protections present */
     91 	uchar_t	prot;		/* current segment prot if pageprot == 0 */
     92 	uchar_t	maxprot;	/* maximum segment protections */
     93 	uchar_t	type;		/* type of sharing done */
     94 	u_offset_t offset;	/* starting offset of vnode for mapping */
     95 	struct	vnode *vp;	/* vnode that segment mapping is to */
     96 	ulong_t	anon_index;	/* starting index into anon_map anon array */
     97 	struct	anon_map *amp;	/* pointer to anon share structure, if needed */
     98 	struct	vpage *vpage;	/* per-page information, if needed */
     99 	struct	cred *cred;	/* mapping credentials */
    100 	size_t	swresv;		/* swap space reserved for this segment */
    101 	uchar_t	advice;		/* madvise flags for segment */
    102 	uchar_t	pageadvice;	/* true if per page advice set */
    103 	ushort_t flags;		/* flags - from sys/mman.h */
    104 	ssize_t	softlockcnt;	/* # of pages SOFTLOCKED in seg */
    105 	lgrp_mem_policy_info_t policy_info; /* memory allocation policy */
    106 	hat_region_cookie_t rcookie;	/* region for hat calls */
    107 	lgrp_mem_policy_info_t tr_policy_info; /* memory allocation for TR */
    108 	struct	seg *seg;	/* pointer back to seg */
    109 	struct	segvn_data *svn_trnext; /* textrepl list next link */
    110 	struct	segvn_data *svn_trprev; /* textrepl list prev link */
    111 	int	tr_state;	/* TR (text replication) state */
    112 } segvn_data_t;
    113 
    114 #ifdef _KERNEL
    115 
    116 /*
    117  * segment text replication states.
    118  */
    119 #define	SEGVN_TR_INIT	(0)	/* Check if text replication can be enabled */
    120 #define	SEGVN_TR_ON	(1)	/* Text replication is enabled */
    121 #define	SEGVN_TR_OFF	(2)	/* Text replication is disabled */
    122 
    123 /*
    124  * Macros for segvn segment driver locking.
    125  */
    126 #define	SEGVN_LOCK_ENTER(as, lock, type)	rw_enter((lock), (type))
    127 #define	SEGVN_LOCK_EXIT(as, lock)		rw_exit((lock))
    128 #define	SEGVN_LOCK_DOWNGRADE(as, lock)		rw_downgrade((lock))
    129 #define	SEGVN_LOCK_TRYENTER(as, lock, type)	rw_tryenter((lock), (type))
    130 
    131 /*
    132  * Macros to test lock states.
    133  */
    134 #define	SEGVN_LOCK_HELD(as, lock)		RW_LOCK_HELD((lock))
    135 #define	SEGVN_READ_HELD(as, lock)		RW_READ_HELD((lock))
    136 #define	SEGVN_WRITE_HELD(as, lock)		RW_WRITE_HELD((lock))
    137 
    138 /*
    139  * Macro used to detect the need to Break the sharing of COW pages
    140  *
    141  * The rw == S_WRITE is for the COW case
    142  * rw == S_READ and type == SOFTLOCK is for the physio case
    143  * We don't want to share a softlocked page because it can cause problems
    144  * with multithreaded apps but if rw == S_READ_NOCOW it's ok to not break
    145  * sharing of COW pages even in SOFTLOCK case.
    146  */
    147 #define	BREAK_COW_SHARE(rw, type, seg_type) ((rw == S_WRITE || \
    148 	(type == F_SOFTLOCK && rw != S_READ_NOCOW)) && \
    149 	seg_type == MAP_PRIVATE)
    150 
    151 #define	SEGVN_ZFOD_ARGS(prot, max)	\
    152 	{ NULL, NULL, 0, MAP_PRIVATE, prot, max, 0, NULL, 0, 0 }
    153 
    154 #define	AS_MAP_CHECK_VNODE_LPOOB(crfp, argsp)				\
    155 	((crfp) == (int (*)())segvn_create &&				\
    156 	(((struct segvn_crargs *)(argsp))->flags &			\
    157 	    (MAP_TEXT | MAP_INITDATA)) &&				\
    158 	((struct segvn_crargs *)(argsp))->szc == 0 &&			\
    159 	((struct segvn_crargs *)(argsp))->vp != NULL)
    160 
    161 #define	AS_MAP_CHECK_ANON_LPOOB(crfp, argsp)				\
    162 	((crfp) == (int (*)())segvn_create &&				\
    163 	(((struct segvn_crargs *)(argsp))->szc == 0 ||			\
    164 	((struct segvn_crargs *)(argsp))->szc == AS_MAP_HEAP ||		\
    165 	((struct segvn_crargs *)(argsp))->szc == AS_MAP_STACK) &&	\
    166 	((struct segvn_crargs *)(argsp))->vp == NULL)
    167 
    168 #define	SVNTR_HASH_FUNC(vp)	(((((uintptr_t)(vp)) >> 4) ^		\
    169 				    (((uintptr_t)(vp)) >> 11)) & 	\
    170 					(svntr_hashtab_sz - 1))
    171 
    172 #define	SEGVN_TR_ADDSTAT(stat)						\
    173 	segvn_textrepl_stats[CPU->cpu_id].tr_stat_##stat++
    174 
    175 /*
    176  * A hash table entry looked up by vnode, off/eoff and szc to find anon map to
    177  * use for text replication based on main thread's (t_tid = 1) lgrp.
    178  */
    179 typedef struct svntr {
    180 	struct vnode	*tr_vp;		/* text file vnode */
    181 	u_offset_t	tr_off;		/* tr_vp mapping start offset */
    182 	size_t		tr_eoff;	/* tr_vp mapping end offset */
    183 	uint_t		tr_szc;		/* tr_vp mapping pagesize */
    184 	int		tr_valid;	/* entry validity state */
    185 	struct svntr	*tr_next;	/* next svntr in this hash bucket */
    186 	timestruc_t	tr_mtime;	/* tr_vp modification time */
    187 	timestruc_t	tr_ctime;	/* time of last change to attributes */
    188 	ulong_t		tr_refcnt;	/* number of segs sharing this entry */
    189 	segvn_data_t	*tr_svnhead;	/* list of segs sharing this entry */
    190 	struct anon_map	*tr_amp[NLGRPS_MAX]; /* per lgrp anon maps */
    191 } svntr_t;
    192 
    193 typedef struct svntr_bucket {
    194 	svntr_t		*tr_head;	/* first svntr in this hash bucket */
    195 	kmutex_t	tr_lock;	/* per bucket lock */
    196 } svntr_bucket_t;
    197 
    198 typedef struct svntr_stats {
    199 	ulong_t		tr_stat_gaerr;   /* VOP_GETATTR() failures */
    200 	ulong_t		tr_stat_overmap; /* no TR due to beyond EOF mappings */
    201 	ulong_t		tr_stat_wrcnt;	 /* no TR due to writtable mappings */
    202 	ulong_t		tr_stat_stale;	 /* TR entry is stale */
    203 	ulong_t		tr_stat_overlap; /* overlap with other mappings */
    204 	ulong_t		tr_stat_nokmem;	 /* no TR due to kmem alloc failures */
    205 	ulong_t		tr_stat_noanon;	 /* no TR due to no swap space */
    206 	ulong_t		tr_stat_normem;  /* no TR due to no repl memory */
    207 	ulong_t		tr_stat_nolock;	 /* async TR failure due to locks */
    208 	ulong_t		tr_stat_asyncrepl; /* number of async TRs */
    209 	ulong_t		tr_stat_repl;	  /* number of sync TRs */
    210 	ulong_t		tr_stat_newamp;	  /* number of new amp allocs for TR */
    211 } svntr_stats_t;
    212 
    213 extern void	segvn_init(void);
    214 extern int	segvn_create(struct seg *, void *);
    215 
    216 extern	struct seg_ops segvn_ops;
    217 
    218 /*
    219  * Provided as shorthand for creating user zfod segments.
    220  */
    221 extern	caddr_t zfod_argsp;
    222 extern	caddr_t kzfod_argsp;
    223 extern	caddr_t stack_exec_argsp;
    224 extern	caddr_t stack_noexec_argsp;
    225 
    226 #endif	/* _KERNEL */
    227 
    228 #ifdef	__cplusplus
    229 }
    230 #endif
    231 
    232 #endif	/* _VM_SEG_VN_H */
    233