xref: /illumos-gate/usr/src/uts/common/vm/seg_vn.h (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 2008 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	"%Z%%M%	%I%	%E% 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 segfree_syncmtx; /* barrier lock for segvn_free() */
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 	spgcnt_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 	uchar_t	pageswap;	/* true if per page swap accounting is set */
113 	spgcnt_t softlockcnt_sbase; /* # of softlocks for seg start addr */
114 	spgcnt_t softlockcnt_send; /* # of softlocks for seg end addr */
115 } segvn_data_t;
116 
117 #ifdef _KERNEL
118 
119 /*
120  * segment text replication states.
121  */
122 #define	SEGVN_TR_INIT	(0)	/* Check if text replication can be enabled */
123 #define	SEGVN_TR_ON	(1)	/* Text replication is enabled */
124 #define	SEGVN_TR_OFF	(2)	/* Text replication is disabled */
125 
126 /*
127  * Macros for segvn segment driver locking.
128  */
129 #define	SEGVN_LOCK_ENTER(as, lock, type)	rw_enter((lock), (type))
130 #define	SEGVN_LOCK_EXIT(as, lock)		rw_exit((lock))
131 #define	SEGVN_LOCK_DOWNGRADE(as, lock)		rw_downgrade((lock))
132 #define	SEGVN_LOCK_TRYENTER(as, lock, type)	rw_tryenter((lock), (type))
133 
134 /*
135  * Macros to test lock states.
136  */
137 #define	SEGVN_LOCK_HELD(as, lock)		RW_LOCK_HELD((lock))
138 #define	SEGVN_READ_HELD(as, lock)		RW_READ_HELD((lock))
139 #define	SEGVN_WRITE_HELD(as, lock)		RW_WRITE_HELD((lock))
140 
141 /*
142  * Macro used to detect the need to Break the sharing of COW pages
143  *
144  * The rw == S_WRITE is for the COW case
145  * rw == S_READ and type == SOFTLOCK is for the physio case
146  * We don't want to share a softlocked page because it can cause problems
147  * with multithreaded apps but if rw == S_READ_NOCOW it's ok to not break
148  * sharing of COW pages even in SOFTLOCK case.
149  */
150 #define	BREAK_COW_SHARE(rw, type, seg_type) ((rw == S_WRITE || \
151 	(type == F_SOFTLOCK && rw != S_READ_NOCOW)) && \
152 	seg_type == MAP_PRIVATE)
153 
154 #define	SEGVN_ZFOD_ARGS(prot, max)	\
155 	{ NULL, NULL, 0, MAP_PRIVATE, prot, max, 0, NULL, 0, 0 }
156 
157 #define	AS_MAP_CHECK_VNODE_LPOOB(crfp, argsp)				\
158 	((crfp) == (int (*)())segvn_create &&				\
159 	(((struct segvn_crargs *)(argsp))->flags &			\
160 	    (MAP_TEXT | MAP_INITDATA)) &&				\
161 	((struct segvn_crargs *)(argsp))->szc == 0 &&			\
162 	((struct segvn_crargs *)(argsp))->vp != NULL)
163 
164 #define	AS_MAP_CHECK_ANON_LPOOB(crfp, argsp)				\
165 	((crfp) == (int (*)())segvn_create &&				\
166 	(((struct segvn_crargs *)(argsp))->szc == 0 ||			\
167 	((struct segvn_crargs *)(argsp))->szc == AS_MAP_HEAP ||		\
168 	((struct segvn_crargs *)(argsp))->szc == AS_MAP_STACK) &&	\
169 	((struct segvn_crargs *)(argsp))->vp == NULL)
170 
171 #define	SVNTR_HASH_FUNC(vp)	(((((uintptr_t)(vp)) >> 4) ^		\
172 				    (((uintptr_t)(vp)) >> 11)) & 	\
173 					(svntr_hashtab_sz - 1))
174 
175 #define	SEGVN_TR_ADDSTAT(stat)						\
176 	segvn_textrepl_stats[CPU->cpu_id].tr_stat_##stat++
177 
178 /*
179  * A hash table entry looked up by vnode, off/eoff and szc to find anon map to
180  * use for text replication based on main thread's (t_tid = 1) lgrp.
181  */
182 typedef struct svntr {
183 	struct vnode	*tr_vp;		/* text file vnode */
184 	u_offset_t	tr_off;		/* tr_vp mapping start offset */
185 	size_t		tr_eoff;	/* tr_vp mapping end offset */
186 	uint_t		tr_szc;		/* tr_vp mapping pagesize */
187 	int		tr_valid;	/* entry validity state */
188 	struct svntr	*tr_next;	/* next svntr in this hash bucket */
189 	timestruc_t	tr_mtime;	/* tr_vp modification time */
190 	timestruc_t	tr_ctime;	/* time of last change to attributes */
191 	ulong_t		tr_refcnt;	/* number of segs sharing this entry */
192 	segvn_data_t	*tr_svnhead;	/* list of segs sharing this entry */
193 	struct anon_map	*tr_amp[NLGRPS_MAX]; /* per lgrp anon maps */
194 } svntr_t;
195 
196 typedef struct svntr_bucket {
197 	svntr_t		*tr_head;	/* first svntr in this hash bucket */
198 	kmutex_t	tr_lock;	/* per bucket lock */
199 } svntr_bucket_t;
200 
201 typedef struct svntr_stats {
202 	ulong_t		tr_stat_gaerr;   /* VOP_GETATTR() failures */
203 	ulong_t		tr_stat_overmap; /* no TR due to beyond EOF mappings */
204 	ulong_t		tr_stat_wrcnt;	 /* no TR due to writtable mappings */
205 	ulong_t		tr_stat_stale;	 /* TR entry is stale */
206 	ulong_t		tr_stat_overlap; /* overlap with other mappings */
207 	ulong_t		tr_stat_nokmem;	 /* no TR due to kmem alloc failures */
208 	ulong_t		tr_stat_noanon;	 /* no TR due to no swap space */
209 	ulong_t		tr_stat_normem;  /* no TR due to no repl memory */
210 	ulong_t		tr_stat_nolock;	 /* async TR failure due to locks */
211 	ulong_t		tr_stat_asyncrepl; /* number of async TRs */
212 	ulong_t		tr_stat_repl;	  /* number of sync TRs */
213 	ulong_t		tr_stat_newamp;	  /* number of new amp allocs for TR */
214 } svntr_stats_t;
215 
216 extern void	segvn_init(void);
217 extern int	segvn_create(struct seg *, void *);
218 
219 extern	struct seg_ops segvn_ops;
220 
221 /*
222  * Provided as shorthand for creating user zfod segments.
223  */
224 extern	caddr_t zfod_argsp;
225 extern	caddr_t kzfod_argsp;
226 extern	caddr_t stack_exec_argsp;
227 extern	caddr_t stack_noexec_argsp;
228 
229 #endif	/* _KERNEL */
230 
231 #ifdef	__cplusplus
232 }
233 #endif
234 
235 #endif	/* _VM_SEG_VN_H */
236