xref: /titanic_41/usr/src/uts/common/vm/seg_vn.h (revision 843e19887f64dde75055cf8842fc4db2171eff45)
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	"%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 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