xref: /titanic_41/usr/src/uts/common/sys/swap.h (revision b6805bf78d2bbbeeaea8909a05623587b42d58b3)
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 (c) 1987, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
26 /*	  All Rights Reserved  	*/
27 
28 /*
29  * University Copyright- Copyright (c) 1982, 1986, 1988
30  * The Regents of the University of California
31  * All Rights Reserved
32  *
33  * University Acknowledgment- Portions of this document are derived from
34  * software developed by the University of California, Berkeley, and its
35  * contributors.
36  */
37 
38 #ifndef	_SYS_SWAP_H
39 #define	_SYS_SWAP_H
40 
41 #include <sys/isa_defs.h>
42 #include <sys/feature_tests.h>
43 #include <vm/anon.h>
44 #include <sys/fs/swapnode.h>
45 
46 #ifdef	__cplusplus
47 extern "C" {
48 #endif
49 
50 #if !defined(_LP64) && _FILE_OFFSET_BITS == 64
51 #error  "Cannot use swapctl in the large files compilation environment"
52 #endif
53 
54 /* The following are for the swapctl system call */
55 
56 #define	SC_ADD		1	/* add a specified resource for swapping */
57 #define	SC_LIST		2	/* list all the swapping resources */
58 #define	SC_REMOVE	3	/* remove the specified swapping resource */
59 #define	SC_GETNSWP	4	/* get number of swap resources configured */
60 #define	SC_AINFO	5	/* get anonymous memory resource information */
61 
62 typedef struct swapres {
63 	char	*sr_name;	/* pathname of the resource specified */
64 	off_t	sr_start;	/* starting offset of the swapping resource */
65 	off_t 	sr_length;	/* length of the swap area */
66 } swapres_t;
67 
68 typedef struct swapent {
69 	char 	*ste_path;	/* get the name of the swap file */
70 	off_t	ste_start;	/* starting block for swapping */
71 	off_t	ste_length;	/* length of swap area */
72 	long	ste_pages;	/* numbers of pages for swapping */
73 	long	ste_free;	/* numbers of ste_pages free */
74 	int	ste_flags;	/* see below */
75 } swapent_t;
76 
77 typedef struct swaptable {
78 	int	swt_n;			/* number of swapents following */
79 	struct	swapent	swt_ent[1];	/* array of swt_n swapents */
80 } swaptbl_t;
81 
82 
83 #if defined(_SYSCALL32)
84 
85 /* Kernel's view of user ILP32 swapres and swapent structures */
86 
87 typedef struct swapres32 {
88 	caddr32_t sr_name;	/* pathname of the resource specified */
89 	off32_t	sr_start;	/* starting offset of the swapping resource */
90 	off32_t	sr_length;	/* length of the swap area */
91 } swapres32_t;
92 
93 typedef struct swapent32 {
94 	caddr32_t ste_path;	/* get the name of the swap file */
95 	off32_t	ste_start;	/* starting block for swapping */
96 	off32_t	ste_length;	/* length of swap area */
97 	int32_t	ste_pages;	/* numbers of pages for swapping */
98 	int32_t	ste_free;	/* numbers of ste_pages free */
99 	int32_t	ste_flags;	/* see below */
100 } swapent32_t;
101 
102 typedef struct	swaptable32 {
103 	int32_t	swt_n;			/* number of swapents following */
104 	struct	swapent32 swt_ent[1];	/* array of swt_n swapents */
105 } swaptbl32_t;
106 
107 #endif	/* _SYSCALL32 */
108 
109 #if defined(_KERNEL)
110 extern int swapctl(int, void *, int *);
111 #if defined(_LP64) && defined(_SYSCALL32)
112 extern int swapctl32(int, void *, int *);
113 #endif /* _LP64 && _SYSCALL32 */
114 #else /* !_KERNEL */
115 #if defined(__STDC__)
116 extern int swapctl(int, void *);
117 #else
118 extern int swapctl();
119 #endif
120 #endif /* _KERNEL */
121 
122 
123 /* ste_flags values */
124 
125 #define	ST_INDEL	0x01		/* Deletion of file is in progress. */
126 					/* Prevents others from deleting or */
127 					/* allocating from it */
128 #define	ST_DOINGDEL	0x02		/* Set during deletion of file */
129 					/* Clearing during deletion signals */
130 					/* that you want to add the file back */
131 					/* again, and will eventually cause */
132 					/* it to be added back */
133 
134 /*
135  * VM - virtual swap device.
136  */
137 struct	swapinfo {
138 	ulong_t si_soff;		/* starting offset (bytes) of file */
139 	ulong_t si_eoff;		/* ending offset (bytes) of file */
140 	struct	vnode *si_vp;		/* vnode (commonvp if device) */
141 	struct	swapinfo *si_next;	/* next swap area */
142 	int	si_allocs;		/* # of conseq. allocs from this area */
143 	short	si_flags;		/* flags defined below */
144 	pgcnt_t	si_npgs;		/* number of pages of swap space */
145 	pgcnt_t	si_nfpgs;		/* number of free pages of swap space */
146 	int 	si_pnamelen;		/* swap file name length + 1 */
147 	char 	*si_pname;		/* swap file name */
148 	ssize_t	si_mapsize;		/* # bytes allocated for bitmap */
149 	uint_t 	*si_swapslots;		/* bitmap of slots, unset == free */
150 	pgcnt_t	si_hint;		/* first page to check if free */
151 	ssize_t	si_checkcnt;		/* # of checks to find freeslot */
152 	ssize_t	si_alloccnt;		/* used to find ave checks */
153 };
154 
155 /*
156  * Stuff to convert an anon slot pointer to a page name.
157  * Because the address of the slot (ap) is a unique identifier, we
158  * use it to generate a unique (vp,off), as shown in the comment for
159  * swap_alloc().
160  *
161  * The off bits are shifted PAGESHIFT to directly form a page aligned
162  * offset; the vp index bits map 1-1 to a vnode.
163  *
164  */
165 #define	MAX_SWAP_VNODES_LOG2	11		/* log2(MAX_SWAP_VNODES) */
166 #define	MAX_SWAP_VNODES	(1U << MAX_SWAP_VNODES_LOG2)	/* max # swap vnodes */
167 #define	AN_VPMASK	(MAX_SWAP_VNODES - 1)	/* vp index mask */
168 #define	AN_VPSHIFT	MAX_SWAP_VNODES_LOG2
169 /*
170  * Convert from an anon slot to associated vnode and offset.
171  */
172 #define	swap_xlate(AP, VPP, OFFP)					\
173 {									\
174 	*(VPP) = (AP)->an_vp;						\
175 	*(OFFP) = (AP)->an_off;						\
176 }
177 #define	swap_xlate_nopanic	swap_xlate
178 
179 /*
180  * Get a vnode name for an anon slot.
181  * The vnum, offset are derived from anon struct address which is
182  * 16 bytes aligned.  anon structs may be kmem_cache_alloc'd concurrently by
183  * multiple threads and come from a small range of addresses (same slab), in
184  * which case high order AP bits do not vary much, so choose vnum from low
185  * order bits which vary the most.  Different threads will thus get different
186  * vnums and vnodes, which avoids vph_mutex_contention on the subsequent
187  * page_hashin().
188  *
189  * +-----------...-------------------+-----------------------+----+
190  * |        swap offset              |           vnum        |0000|
191  * +-----------...-------------------+-----------------------+----+
192  *  63                             15 14                    4 3   0
193  */
194 #define	swap_alloc(AP)							\
195 {									\
196 	(AP)->an_vp = swapfs_getvp(((uintptr_t)(AP) >> AN_CACHE_ALIGN_LOG2) \
197 	    & AN_VPMASK); 						\
198 	(AP)->an_off = (anoff_t)((((uintptr_t)(AP)) >>			\
199 	    AN_VPSHIFT + AN_CACHE_ALIGN_LOG2) << PAGESHIFT);		\
200 }
201 
202 /*
203  * Free the page name for the specified anon slot.
204  * For now there's nothing to do.
205  */
206 #define	swap_free(AP)
207 
208 /* Flags for swap_phys_alloc */
209 #define	SA_NOT 	0x01 	/* Must have slot from swap dev other than input one */
210 
211 /* Special error codes for swap_newphysname() */
212 #define	SE_NOSWAP	-1	/* No physical swap slots available */
213 #define	SE_NOANON	-2	/* No anon slot for swap slot */
214 
215 #ifdef _KERNEL
216 extern struct anon *swap_anon(struct vnode *vp, u_offset_t off);
217 extern int swap_phys_alloc(struct vnode **vpp, u_offset_t *offp, size_t *lenp,
218     uint_t flags);
219 extern void swap_phys_free(struct vnode *vp, u_offset_t off, size_t len);
220 extern int swap_getphysname(struct vnode *vp, u_offset_t off,
221     struct vnode **pvpp, u_offset_t *poffp);
222 extern int swap_newphysname(struct vnode *vp, u_offset_t offset,
223     u_offset_t *offp, size_t *lenp, struct vnode **pvpp, u_offset_t *poffp);
224 
225 extern struct swapinfo *swapinfo;
226 extern int swap_debug;
227 #endif	/* _KERNEL */
228 
229 #ifdef SWAP_DEBUG
230 #define	SW_RENAME	0x01
231 #define	SW_RESV		0x02
232 #define	SW_ALLOC	0x04
233 #define	SW_CTL		0x08
234 #define	SWAP_PRINT(f, s, x1, x2, x3, x4, x5) \
235 		if (swap_debug & f) \
236 			printf(s, x1, x2, x3, x4, x5);
237 #else	/* SWAP_DEBUG */
238 #define	SWAP_PRINT(f, s, x1, x2, x3, x4, x5)
239 #endif	/* SWAP_DEBUG */
240 
241 #ifdef	__cplusplus
242 }
243 #endif
244 
245 #endif	/* _SYS_SWAP_H */
246