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      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	"@(#)seg_kp.h	1.24	05/06/08 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