xref: /illumos-gate/usr/src/uts/common/vm/seg_kp.h (revision 24da5b34f49324ed742a340010ed5bd3d4e06625)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef	_VM_SEG_KP_H
28 #define	_VM_SEG_KP_H
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * segkp (as in kernel pageable) is a segment driver that supports allocation
34  * of page-aligned variable size of vm resources.
35  *
36  * Each vm resource represents a page-aligned range of virtual addresses.
37  * The caller may specify whether the resource should include a redzone,
38  * be locked down, or be zero initialized.
39  */
40 
41 #include <vm/seg.h>
42 #include <sys/vmem.h>
43 
44 #ifdef	__cplusplus
45 extern "C" {
46 #endif
47 
48 #ifdef	_KERNEL
49 
50 /*
51  * Private information per overall segkp segment (as opposed
52  * to per resource within segment). There are as many anon slots
53  * allocated as there there are pages in the segment.
54  */
55 struct segkp_segdata {
56 	struct anon_hdr	*kpsd_anon;	/* anon structs */
57 	vmem_t		*kpsd_arena; 	/* virtual memory descriptor */
58 	struct segkp_data **kpsd_hash;	/* Hash table for lookups */
59 };
60 
61 #define	SEGKP_VMEM(seg)	(((struct segkp_segdata *)(seg)->s_data)->kpsd_arena)
62 
63 /*
64  * A hash table is used to aid in the lookup of a kpd's based on vaddr.
65  * Since the heaviest use of segkp occurs from segkp_*get and segkp_*release,
66  * the hashing is based on the vaddr used by these routines.
67  */
68 #define	SEGKP_HASHSZ		256	/* power of two */
69 #define	SEGKP_HASHMASK		(SEGKP_HASHSZ - 1)
70 #define	SEGKP_HASH(vaddr)	\
71 	((int)(((uintptr_t)vaddr >> PAGESHIFT) & SEGKP_HASHMASK))
72 
73 struct segkp_data {
74 	kmutex_t	kp_lock;	/* per resource lock */
75 	caddr_t		kp_base;	/* starting addr of chunk */
76 	size_t		kp_len;		/* # of bytes */
77 	uint_t		kp_flags;	/* state info */
78 	int		kp_cookie;	/* index into cache array */
79 	ulong_t		kp_anon_idx;	/* index into main anon array */
80 					/* in segkp_segdata */
81 	struct anon_hdr	*kp_anon;	/* anon structs */
82 	struct segkp_data *kp_next;	/* ptr to next in hash chain */
83 };
84 
85 /*
86  * Flag bits
87  *
88  */
89 #define	KPD_ZERO	0x01		/* initialize resource with 0 */
90 #define	KPD_LOCKED	0x02		/* resources locked */
91 #define	KPD_NO_ANON	0x04		/* no swap resources required */
92 #define	KPD_HASREDZONE	0x08		/* include a redzone */
93 #define	KPD_NOWAIT	0x10		/* do not wait for res. if unavail. */
94 #define	KPD_WRITEDIRTY	0x20		/* dirty pages should be flushed */
95 #define	KPD_HASAMP	0x40		/* anon_hdr managed by caller */
96 
97 /*
98  * A cache of segkp elements may be created via segkp_cache_init().
99  * The elements on the freelist all have the same len and flags value.
100  * The cookie passed to the client is an index into the freelist array.
101  */
102 struct segkp_cache  {
103 	int		kpf_max;		/* max # of elements allowed */
104 	int		kpf_count;		/* current no. of elments */
105 	int		kpf_inuse;		/* list inuse */
106 	uint_t		kpf_flags;		/* seg_kp flag value */
107 	size_t		kpf_len;		/* len of resource */
108 	struct seg	*kpf_seg;		/* segment */
109 	struct segkp_data *kpf_list;		/* list of kpd's */
110 };
111 #define	SEGKP_MAX_CACHE		4	/* Number of caches maintained */
112 
113 /*
114  * Define redzone, and stack_to_memory macros.
115  * The redzone is PAGESIZE bytes.
116  */
117 #ifdef	STACK_GROWTH_DOWN
118 #define	KPD_REDZONE(kpd)	(0)
119 #define	stom(v, flags)	(((flags) & KPD_HASREDZONE) ? (v) + PAGESIZE : (v))
120 
121 #else	/* STACK_GROWTH_DOWN */
122 
123 #define	KPD_REDZONE(kpd) (btop(kpd->kp_len) - 1)
124 #define	stom(v)	(v)
125 #endif	/* STACK_GROWTH_DOWN */
126 
127 #define	SEGKP_MAPLEN(len, flags) \
128 	(((flags) & KPD_HASREDZONE) ? (len) - PAGESIZE : (len))
129 
130 extern	struct seg *segkp;
131 /* If segkp becomes more than one seg this test will need changing. */
132 #define	SEG_IS_SEGKP(SEG)	((SEG) == segkp)
133 
134 /*
135  * Public routine declarations not part of the segment ops vector go here.
136  */
137 int	segkp_create(struct seg *seg);
138 caddr_t	segkp_get(struct seg *seg, size_t len, uint_t flags);
139 void	segkp_release(struct seg *seg, caddr_t vaddr);
140 void *  segkp_cache_init(struct seg *seg, int maxsize, size_t len,
141 		uint_t flags);
142 void	segkp_cache_free();
143 caddr_t segkp_cache_get(void *cookie);
144 int	segkp_map_red(void);
145 void	segkp_unmap_red(void);
146 size_t	swapsize(caddr_t v);
147 
148 /* Special currently only used by schedctl. */
149 struct anon_map;	/* Make the compiler happy about the next line. */
150 caddr_t segkp_get_withanonmap(struct seg *, size_t, uint_t, struct anon_map *);
151 
152 /*
153  * We allow explicit calls to segkp_fault, even though it's part
154  * of the segkp ops vector.
155  */
156 faultcode_t segkp_fault(struct hat *hat, struct seg *seg, caddr_t addr,
157 	size_t len, enum fault_type type, enum seg_rw rw);
158 
159 #endif	/* _KERNEL */
160 
161 #ifdef	__cplusplus
162 }
163 #endif
164 
165 #endif	/* _VM_SEG_KP_H */
166