xref: /illumos-gate/usr/src/uts/common/vm/as.h (revision 284ce987)
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  */
25 
26 /*
27  * Copyright 2018 Joyent, Inc.
28  */
29 
30 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
31 /*	 All Rights Reserved   */
32 
33 /*
34  * University Copyright- Copyright (c) 1982, 1986, 1988
35  * The Regents of the University of California
36  * All Rights Reserved
37  *
38  * University Acknowledgment- Portions of this document are derived from
39  * software developed by the University of California, Berkeley, and its
40  * contributors.
41  */
42 
43 #ifndef	_VM_AS_H
44 #define	_VM_AS_H
45 
46 #include <sys/watchpoint.h>
47 #include <vm/seg.h>
48 #include <vm/faultcode.h>
49 #include <vm/hat.h>
50 #include <sys/avl.h>
51 #include <sys/proc.h>
52 
53 #ifdef	__cplusplus
54 extern "C" {
55 #endif
56 
57 /*
58  * VM - Address spaces.
59  */
60 
61 /*
62  * Each address space consists of a sorted list of segments
63  * and machine dependent address translation information.
64  *
65  * All the hard work is in the segment drivers and the
66  * hardware address translation code.
67  *
68  * The segment list is represented as an AVL tree.
69  *
70  * The address space lock (a_lock) is a long term lock which serializes
71  * access to certain operations (as_map, as_unmap) and protects the
72  * underlying generic segment data (seg.h) along with some fields in the
73  * address space structure as shown below:
74  *
75  *	address space structure 	segment structure
76  *
77  *	a_segtree			s_base
78  *	a_size				s_size
79  *	a_lastgap			s_link
80  *	a_seglast			s_ops
81  *					s_as
82  *					s_data
83  *
84  * The address space contents lock (a_contents) is a short term
85  * lock that protects most of the data in the address space structure.
86  * This lock is always acquired after the "a_lock" in all situations
87  * except while dealing with AS_CLAIMGAP to avoid deadlocks.
88  *
89  * The following fields are protected by this lock:
90  *
91  *	a_flags (AS_PAGLCK, AS_CLAIMGAP, etc.)
92  *	a_unmapwait
93  *	a_seglast
94  *
95  * The address space lock (a_lock) is always held prior to any segment
96  * operation.  Some segment drivers use the address space lock to protect
97  * some or all of their segment private data, provided the version of
98  * "a_lock" (read vs. write) is consistent with the use of the data.
99  *
100  * The following fields are protected by the hat layer lock:
101  *
102  *	a_vbits
103  *	a_hat
104  *	a_hrm
105  */
106 
107 struct as {
108 	kmutex_t a_contents;	/* protect certain fields in the structure */
109 	uchar_t  a_flags;	/* as attributes */
110 	uchar_t	a_vbits;	/* used for collecting statistics */
111 	kcondvar_t a_cv;	/* used by as_rangelock */
112 	struct	hat *a_hat;	/* hat structure */
113 	struct	hrmstat *a_hrm; /* ref and mod bits */
114 	caddr_t	a_userlimit;	/* highest allowable address in this as */
115 	struct seg *a_seglast;	/* last segment hit on the addr space */
116 	krwlock_t a_lock;	/* protects segment related fields */
117 	size_t	a_size;		/* total size of address space */
118 	struct seg *a_lastgap;	/* last seg found by as_gap() w/ AS_HI (mmap) */
119 	struct seg *a_lastgaphl; /* last seg saved in as_gap() either for */
120 				/* AS_HI or AS_LO used in as_addseg() */
121 	avl_tree_t a_segtree;	/* segments in this address space. (AVL tree) */
122 	avl_tree_t a_wpage;	/* watched pages (procfs) */
123 	uchar_t	a_updatedir;	/* mappings changed, rebuild a_objectdir */
124 	timespec_t a_updatetime;	/* time when mappings last changed */
125 	vnode_t	**a_objectdir;	/* object directory (procfs) */
126 	size_t	a_sizedir;	/* size of object directory */
127 	struct as_callback *a_callbacks; /* callback list */
128 	proc_t	*a_proc;	/* back pointer to proc */
129 	size_t	a_resvsize;	/* size of reserved part of address space */
130 };
131 
132 #define	AS_PAGLCK		0x80
133 #define	AS_CLAIMGAP		0x40
134 #define	AS_UNMAPWAIT		0x20
135 #define	AS_NEEDSPURGE		0x10	/* mostly for seg_nf, see as_purge() */
136 #define	AS_NOUNMAPWAIT		0x02
137 
138 #define	AS_ISPGLCK(as)		((as)->a_flags & AS_PAGLCK)
139 #define	AS_ISCLAIMGAP(as)	((as)->a_flags & AS_CLAIMGAP)
140 #define	AS_ISUNMAPWAIT(as)	((as)->a_flags & AS_UNMAPWAIT)
141 #define	AS_ISNOUNMAPWAIT(as)	((as)->a_flags & AS_NOUNMAPWAIT)
142 
143 #define	AS_SETPGLCK(as)		((as)->a_flags |= AS_PAGLCK)
144 #define	AS_SETCLAIMGAP(as)	((as)->a_flags |= AS_CLAIMGAP)
145 #define	AS_SETUNMAPWAIT(as)	((as)->a_flags |= AS_UNMAPWAIT)
146 #define	AS_SETNOUNMAPWAIT(as)	((as)->a_flags |= AS_NOUNMAPWAIT)
147 
148 #define	AS_CLRPGLCK(as)		((as)->a_flags &= ~AS_PAGLCK)
149 #define	AS_CLRCLAIMGAP(as)	((as)->a_flags &= ~AS_CLAIMGAP)
150 #define	AS_CLRUNMAPWAIT(as)	((as)->a_flags &= ~AS_UNMAPWAIT)
151 #define	AS_CLRNOUNMAPWAIT(as)	((as)->a_flags &= ~AS_NOUNMAPWAIT)
152 
153 #define	AS_TYPE_64BIT(as)	\
154 	    (((as)->a_userlimit > (caddr_t)UINT32_MAX) ? 1 : 0)
155 
156 /*
157  * Flags for as_map/as_map_ansegs
158  */
159 #define	AS_MAP_NO_LPOOB		((uint_t)-1)
160 #define	AS_MAP_HEAP		((uint_t)-2)
161 #define	AS_MAP_STACK		((uint_t)-3)
162 
163 /*
164  * The as_callback is the basic structure which supports the ability to
165  * inform clients of specific events pertaining to address space management.
166  * A user calls as_add_callback to register an address space callback
167  * for a range of pages, specifying the events that need to occur.
168  * When as_do_callbacks is called and finds a 'matching' entry, the
169  * callback is called once, and the callback function MUST call
170  * as_delete_callback when all callback activities are complete.
171  * The thread calling as_do_callbacks blocks until the as_delete_callback
172  * is called.  This allows for asynchorous events to subside before the
173  * as_do_callbacks thread continues.
174  *
175  * An example of the need for this is a driver which has done long-term
176  * locking of memory.  Address space management operations (events) such
177  * as as_free, as_umap, and as_setprot will block indefinitely until the
178  * pertinent memory is unlocked.  The callback mechanism provides the
179  * way to inform the driver of the event so that the driver may do the
180  * necessary unlocking.
181  *
182  * The contents of this structure is protected by a_contents lock
183  */
184 typedef void (*callback_func_t)(struct as *, void *, uint_t);
185 struct as_callback {
186 	struct as_callback	*ascb_next;		/* list link */
187 	uint_t			ascb_events;		/* event types */
188 	callback_func_t		ascb_func;   		/* callback function */
189 	void			*ascb_arg;		/* callback argument */
190 	caddr_t			ascb_saddr;		/* start address */
191 	size_t			ascb_len;		/* address range */
192 };
193 /*
194  * Callback events
195  */
196 #define	AS_FREE_EVENT		0x1
197 #define	AS_SETPROT_EVENT	0x2
198 #define	AS_UNMAP_EVENT		0x4
199 #define	AS_CALLBACK_CALLED	((uint_t)(1U << (8 * sizeof (uint_t) - 1U)))
200 #define	AS_UNMAPWAIT_EVENT				\
201 		(AS_FREE_EVENT | AS_SETPROT_EVENT | AS_UNMAP_EVENT)
202 #define	AS_ALL_EVENT					\
203 		(AS_FREE_EVENT | AS_SETPROT_EVENT | AS_UNMAP_EVENT)
204 
205 
206 /* Return code values for as_callback_delete */
207 enum as_cbdelete_rc {
208 	AS_CALLBACK_DELETED,
209 	AS_CALLBACK_NOTFOUND,
210 	AS_CALLBACK_DELETE_DEFERRED
211 };
212 
213 #ifdef _KERNEL
214 
215 /*
216  * Flags for as_gap.
217  */
218 #define	AH_DIR		0x1	/* direction flag mask */
219 #define	AH_LO		0x0	/* find lowest hole */
220 #define	AH_HI		0x1	/* find highest hole */
221 #define	AH_CONTAIN	0x2	/* hole must contain `addr' */
222 
223 extern struct as kas;		/* kernel's address space */
224 
225 /*
226  * Macros for address space locking.  Note that we use RW_READER_STARVEWRITER
227  * whenever we acquire the address space lock as reader to assure that it can
228  * be used without regard to lock order in conjunction with filesystem locks.
229  * This allows filesystems to safely induce user-level page faults with
230  * filesystem locks held while concurrently allowing filesystem entry points
231  * acquiring those same locks to be called with the address space lock held as
232  * reader.  RW_READER_STARVEWRITER thus prevents reader/reader+RW_WRITE_WANTED
233  * deadlocks in the style of fop_write()+as_fault()/as_*()+fop_putpage() and
234  * fop_read()+as_fault()/as_*()+fop_getpage().  (See the Big Theory Statement
235  * in rwlock.c for more information on the semantics of and motivation behind
236  * RW_READER_STARVEWRITER.)
237  */
238 #define	AS_LOCK_ENTER(as, type)		rw_enter(&(as)->a_lock, \
239 	(type) == RW_READER ? RW_READER_STARVEWRITER : (type))
240 #define	AS_LOCK_EXIT(as)		rw_exit(&(as)->a_lock)
241 #define	AS_LOCK_DESTROY(as)		rw_destroy(&(as)->a_lock)
242 #define	AS_LOCK_TRYENTER(as, type)	rw_tryenter(&(as)->a_lock, \
243 	(type) == RW_READER ? RW_READER_STARVEWRITER : (type))
244 
245 /*
246  * Macros to test lock states.
247  */
248 #define	AS_LOCK_HELD(as)		RW_LOCK_HELD(&(as)->a_lock)
249 #define	AS_READ_HELD(as)		RW_READ_HELD(&(as)->a_lock)
250 #define	AS_WRITE_HELD(as)		RW_WRITE_HELD(&(as)->a_lock)
251 
252 /*
253  * macros to walk thru segment lists
254  */
255 #define	AS_SEGFIRST(as)		avl_first(&(as)->a_segtree)
256 #define	AS_SEGNEXT(as, seg)	AVL_NEXT(&(as)->a_segtree, (seg))
257 #define	AS_SEGPREV(as, seg)	AVL_PREV(&(as)->a_segtree, (seg))
258 
259 typedef int (*segcreate_func_t)(struct seg **, void *);
260 
261 void	as_init(void);
262 void	as_avlinit(struct as *);
263 struct	seg *as_segat(struct as *as, caddr_t addr);
264 void	as_rangelock(struct as *as);
265 void	as_rangeunlock(struct as *as);
266 struct	as *as_alloc();
267 void	as_free(struct as *as);
268 int	as_dup(struct as *as, struct proc *forkedproc);
269 struct	seg *as_findseg(struct as *as, caddr_t addr, int tail);
270 int	as_addseg(struct as *as, struct seg *newseg);
271 struct	seg *as_removeseg(struct as *as, struct seg *seg);
272 faultcode_t as_fault(struct hat *hat, struct as *as, caddr_t addr, size_t size,
273 		enum fault_type type, enum seg_rw rw);
274 faultcode_t as_faulta(struct as *as, caddr_t addr, size_t size);
275 int	as_setprot(struct as *as, caddr_t addr, size_t size, uint_t prot);
276 int	as_checkprot(struct as *as, caddr_t addr, size_t size, uint_t prot);
277 int	as_unmap(struct as *as, caddr_t addr, size_t size);
278 int	as_map(struct as *as, caddr_t addr, size_t size, segcreate_func_t crfp,
279     void *argsp);
280 int as_map_locked(struct as *as, caddr_t addr, size_t size,
281     segcreate_func_t crfp, void *argsp);
282 void	as_purge(struct as *as);
283 int	as_gap(struct as *as, size_t minlen, caddr_t *basep, size_t *lenp,
284 		uint_t flags, caddr_t addr);
285 int	as_gap_aligned(struct as *as, size_t minlen, caddr_t *basep,
286 	    size_t *lenp, uint_t flags, caddr_t addr, size_t align,
287 	    size_t redzone, size_t off);
288 
289 int	as_memory(struct as *as, caddr_t *basep, size_t *lenp);
290 size_t	as_swapout(struct as *as);
291 int	as_incore(struct as *as, caddr_t addr, size_t size, char *vec,
292 		size_t *sizep);
293 int	as_ctl(struct as *as, caddr_t addr, size_t size, int func, int attr,
294 		uintptr_t arg, ulong_t *lock_map, size_t pos);
295 int	as_pagelock(struct as *as, struct page ***ppp, caddr_t addr,
296 		size_t size, enum seg_rw rw);
297 void	as_pageunlock(struct as *as, struct page **pp, caddr_t addr,
298 		size_t size, enum seg_rw rw);
299 int	as_setpagesize(struct as *as, caddr_t addr, size_t size, uint_t szc,
300 		boolean_t wait);
301 int	as_set_default_lpsize(struct as *as, caddr_t addr, size_t size);
302 void	as_setwatch(struct as *as);
303 void	as_clearwatch(struct as *as);
304 int	as_getmemid(struct as *, caddr_t, memid_t *);
305 
306 int	as_add_callback(struct as *, void (*)(), void *, uint_t,
307 			caddr_t, size_t, int);
308 uint_t	as_delete_callback(struct as *, void *);
309 
310 #endif	/* _KERNEL */
311 
312 #ifdef	__cplusplus
313 }
314 #endif
315 
316 #endif	/* _VM_AS_H */
317