xref: /titanic_52/usr/src/uts/common/vm/seg_vn.h (revision 9d12795f87b63c2e39e87bff369182edd34677d3)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  * Copyright (c) 2015, Joyent, Inc.  All rights reserved.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #ifndef	_VM_SEG_VN_H
41 #define	_VM_SEG_VN_H
42 
43 #include <sys/lgrp.h>
44 #include <vm/anon.h>
45 
46 #ifdef	__cplusplus
47 extern "C" {
48 #endif
49 
50 /*
51  * A pointer to this structure is passed to segvn_create().
52  */
53 typedef struct segvn_crargs {
54 	struct	vnode *vp;	/* vnode mapped from */
55 	struct	cred *cred;	/* credentials */
56 	u_offset_t	offset; /* starting offset of vnode for mapping */
57 	uchar_t	type;		/* type of sharing done */
58 	uchar_t	prot;		/* protections */
59 	uchar_t	maxprot;	/* maximum protections */
60 	uint_t	flags;		/* flags */
61 	struct	anon_map *amp;	/* anon mapping to map to */
62 	uint_t	szc;		/* max preferred page size code */
63 	uint_t	lgrp_mem_policy_flags;
64 } segvn_crargs_t;
65 
66 /*
67  * (Semi) private data maintained by the seg_vn driver per segment mapping.
68  *
69  * The read/write segment lock protects all of segvn_data including the
70  * vpage array.  All fields in segvn_data are treated as read-only when
71  * the "read" version of the address space and the segment locks are held.
72  * The "write" version of the segment lock, however, is required in order to
73  * update the following fields:
74  *
75  *	pageprot
76  *	prot
77  *	amp
78  *	vpage
79  *
80  * 	softlockcnt
81  * is written by acquiring either the readers lock on the segment and
82  * freemem lock, or any lock combination which guarantees exclusive use
83  * of this segment (e.g., adress space writers lock,
84  * address space readers lock + segment writers lock).
85  */
86 typedef struct	segvn_data {
87 	krwlock_t lock;		/* protect segvn_data and vpage array */
88 	kmutex_t segfree_syncmtx; /* barrier lock for segvn_free() */
89 	uchar_t	pageprot;	/* true if per page protections present */
90 	uchar_t	prot;		/* current segment prot if pageprot == 0 */
91 	uchar_t	maxprot;	/* maximum segment protections */
92 	uchar_t	type;		/* type of sharing done */
93 	u_offset_t offset;	/* starting offset of vnode for mapping */
94 	struct	vnode *vp;	/* vnode that segment mapping is to */
95 	ulong_t	anon_index;	/* starting index into anon_map anon array */
96 	struct	anon_map *amp;	/* pointer to anon share structure, if needed */
97 	struct	vpage *vpage;	/* per-page information, if needed */
98 	struct	cred *cred;	/* mapping credentials */
99 	size_t	swresv;		/* swap space reserved for this segment */
100 	uchar_t	advice;		/* madvise flags for segment */
101 	uchar_t	pageadvice;	/* true if per page advice set */
102 	uchar_t svn_inz;	/* true if pages marked as inherit zero */
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  * Inherit zero states
128  */
129 #define	SEGVN_INZ_NONE	(0)	/* Nothing in the segment is inherit zero */
130 #define	SEGVN_INZ_ALL	(1)	/* Everything in the segment is inherit zero */
131 #define	SEGVN_INZ_VPP	(2)	/* Check struct vpages for inherit zero */
132 
133 /*
134  * Macros for segvn segment driver locking.
135  */
136 #define	SEGVN_LOCK_ENTER(as, lock, type)	rw_enter((lock), (type))
137 #define	SEGVN_LOCK_EXIT(as, lock)		rw_exit((lock))
138 #define	SEGVN_LOCK_DOWNGRADE(as, lock)		rw_downgrade((lock))
139 #define	SEGVN_LOCK_TRYENTER(as, lock, type)	rw_tryenter((lock), (type))
140 
141 /*
142  * Macros to test lock states.
143  */
144 #define	SEGVN_LOCK_HELD(as, lock)		RW_LOCK_HELD((lock))
145 #define	SEGVN_READ_HELD(as, lock)		RW_READ_HELD((lock))
146 #define	SEGVN_WRITE_HELD(as, lock)		RW_WRITE_HELD((lock))
147 
148 /*
149  * Macro used to detect the need to Break the sharing of COW pages
150  *
151  * The rw == S_WRITE is for the COW case
152  * rw == S_READ and type == SOFTLOCK is for the physio case
153  * We don't want to share a softlocked page because it can cause problems
154  * with multithreaded apps but if rw == S_READ_NOCOW it's ok to not break
155  * sharing of COW pages even in SOFTLOCK case.
156  */
157 #define	BREAK_COW_SHARE(rw, type, seg_type) ((rw == S_WRITE || \
158 	(type == F_SOFTLOCK && rw != S_READ_NOCOW)) && \
159 	seg_type == MAP_PRIVATE)
160 
161 #define	SEGVN_ZFOD_ARGS(prot, max)	\
162 	{ NULL, NULL, 0, MAP_PRIVATE, prot, max, 0, NULL, 0, 0 }
163 
164 #define	AS_MAP_CHECK_VNODE_LPOOB(crfp, argsp)				\
165 	((crfp) == (int (*)())segvn_create &&				\
166 	(((struct segvn_crargs *)(argsp))->flags &			\
167 	    (MAP_TEXT | MAP_INITDATA)) &&				\
168 	((struct segvn_crargs *)(argsp))->szc == 0 &&			\
169 	((struct segvn_crargs *)(argsp))->vp != NULL)
170 
171 #define	AS_MAP_CHECK_ANON_LPOOB(crfp, argsp)				\
172 	((crfp) == (int (*)())segvn_create &&				\
173 	(((struct segvn_crargs *)(argsp))->szc == 0 ||			\
174 	((struct segvn_crargs *)(argsp))->szc == AS_MAP_HEAP ||		\
175 	((struct segvn_crargs *)(argsp))->szc == AS_MAP_STACK) &&	\
176 	((struct segvn_crargs *)(argsp))->vp == NULL)
177 
178 #define	SVNTR_HASH_FUNC(vp)	(((((uintptr_t)(vp)) >> 4) ^		\
179 				    (((uintptr_t)(vp)) >> 11)) & 	\
180 					(svntr_hashtab_sz - 1))
181 
182 #define	SEGVN_TR_ADDSTAT(stat)						\
183 	segvn_textrepl_stats[CPU->cpu_id].tr_stat_##stat++
184 
185 #define	SEGVN_DATA(seg)	((struct segvn_data *)(seg)->s_data)
186 #define	SEG_IS_PARTIAL_RESV(seg)	\
187 	((seg)->s_ops == &segvn_ops && SEGVN_DATA(seg) != NULL && \
188 	(SEGVN_DATA(seg)->vp == NULL || \
189 	SEGVN_DATA(seg)->vp->v_type != VREG) &&	\
190 	(SEGVN_DATA(seg)->flags & MAP_NORESERVE))
191 
192 /*
193  * A hash table entry looked up by vnode, off/eoff and szc to find anon map to
194  * use for text replication based on main thread's (t_tid = 1) lgrp.
195  */
196 typedef struct svntr {
197 	struct vnode	*tr_vp;		/* text file vnode */
198 	u_offset_t	tr_off;		/* tr_vp mapping start offset */
199 	size_t		tr_eoff;	/* tr_vp mapping end offset */
200 	uint_t		tr_szc;		/* tr_vp mapping pagesize */
201 	int		tr_valid;	/* entry validity state */
202 	struct svntr	*tr_next;	/* next svntr in this hash bucket */
203 	timestruc_t	tr_mtime;	/* tr_vp modification time */
204 	timestruc_t	tr_ctime;	/* time of last change to attributes */
205 	ulong_t		tr_refcnt;	/* number of segs sharing this entry */
206 	segvn_data_t	*tr_svnhead;	/* list of segs sharing this entry */
207 	struct anon_map	*tr_amp[NLGRPS_MAX]; /* per lgrp anon maps */
208 } svntr_t;
209 
210 typedef struct svntr_bucket {
211 	svntr_t		*tr_head;	/* first svntr in this hash bucket */
212 	kmutex_t	tr_lock;	/* per bucket lock */
213 } svntr_bucket_t;
214 
215 typedef struct svntr_stats {
216 	ulong_t		tr_stat_gaerr;   /* VOP_GETATTR() failures */
217 	ulong_t		tr_stat_overmap; /* no TR due to beyond EOF mappings */
218 	ulong_t		tr_stat_wrcnt;	 /* no TR due to writtable mappings */
219 	ulong_t		tr_stat_stale;	 /* TR entry is stale */
220 	ulong_t		tr_stat_overlap; /* overlap with other mappings */
221 	ulong_t		tr_stat_nokmem;	 /* no TR due to kmem alloc failures */
222 	ulong_t		tr_stat_noanon;	 /* no TR due to no swap space */
223 	ulong_t		tr_stat_normem;  /* no TR due to no repl memory */
224 	ulong_t		tr_stat_nolock;	 /* async TR failure due to locks */
225 	ulong_t		tr_stat_asyncrepl; /* number of async TRs */
226 	ulong_t		tr_stat_repl;	  /* number of sync TRs */
227 	ulong_t		tr_stat_newamp;	  /* number of new amp allocs for TR */
228 } svntr_stats_t;
229 
230 extern void	segvn_init(void);
231 extern int	segvn_create(struct seg *, void *);
232 
233 extern	struct seg_ops segvn_ops;
234 
235 /*
236  * Provided as shorthand for creating user zfod segments.
237  */
238 extern	caddr_t zfod_argsp;
239 extern	caddr_t kzfod_argsp;
240 extern	caddr_t stack_exec_argsp;
241 extern	caddr_t stack_noexec_argsp;
242 
243 #endif	/* _KERNEL */
244 
245 #ifdef	__cplusplus
246 }
247 #endif
248 
249 #endif	/* _VM_SEG_VN_H */
250