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
45extern "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 */
55struct 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
73struct 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 */
102struct 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
130extern	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 */
137int	segkp_create(struct seg *seg);
138caddr_t	segkp_get(struct seg *seg, size_t len, uint_t flags);
139void	segkp_release(struct seg *seg, caddr_t vaddr);
140void *  segkp_cache_init(struct seg *seg, int maxsize, size_t len,
141		uint_t flags);
142void	segkp_cache_free();
143caddr_t segkp_cache_get(void *cookie);
144int	segkp_map_red(void);
145void	segkp_unmap_red(void);
146size_t	swapsize(caddr_t v);
147
148/* Special currently only used by schedctl. */
149struct anon_map;	/* Make the compiler happy about the next line. */
150caddr_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 */
156faultcode_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