xref: /onnv-gate/usr/src/uts/common/os/id32.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #include <sys/vmem.h>
30*0Sstevel@tonic-gate #include <sys/kmem.h>
31*0Sstevel@tonic-gate #include <sys/param.h>
32*0Sstevel@tonic-gate #include <sys/sysmacros.h>
33*0Sstevel@tonic-gate #include <sys/cmn_err.h>
34*0Sstevel@tonic-gate #include <vm/seg_kmem.h>
35*0Sstevel@tonic-gate 
36*0Sstevel@tonic-gate static vmem_t *id32_arena;
37*0Sstevel@tonic-gate static kmem_cache_t *id32_cache;
38*0Sstevel@tonic-gate 
39*0Sstevel@tonic-gate #define	ID32_BITS	5
40*0Sstevel@tonic-gate #define	ID32_ALIGN	(1 << ID32_BITS)
41*0Sstevel@tonic-gate #define	ID32_MOD	(ID32_ALIGN - 1)
42*0Sstevel@tonic-gate 
43*0Sstevel@tonic-gate #if defined(__amd64)
44*0Sstevel@tonic-gate /*
45*0Sstevel@tonic-gate  * For amd64 the 32 bit id is the offset of the entry in the arena.
46*0Sstevel@tonic-gate  */
47*0Sstevel@tonic-gate extern char *heap_core_base;
48*0Sstevel@tonic-gate #define	ID32_ENCODE(x)	(((x) - (uintptr_t)heap_core_base) | \
49*0Sstevel@tonic-gate 	((((x) - (uintptr_t)heap_core_base) % ID32_MOD)) + 1)
50*0Sstevel@tonic-gate #define	ID32_DECODE(x)	(P2ALIGN((x), (uintptr_t)ID32_ALIGN) + \
51*0Sstevel@tonic-gate 	(uintptr_t)heap_core_base)
52*0Sstevel@tonic-gate #define	ID32_VALID(x)	(ID32_ENCODE(ID32_DECODE(x)) == (x))
53*0Sstevel@tonic-gate #else	/* __amd64 */
54*0Sstevel@tonic-gate /*
55*0Sstevel@tonic-gate  * All other architectures use the 32 bit pointer value for the 32 bit id.
56*0Sstevel@tonic-gate  */
57*0Sstevel@tonic-gate #define	ID32_ENCODE(x)	(((x) | ((x) % ID32_MOD)) + 1)
58*0Sstevel@tonic-gate #define	ID32_DECODE(x)	P2ALIGN((x), ID32_ALIGN)
59*0Sstevel@tonic-gate #define	ID32_VALID(x)	(ID32_ENCODE(ID32_DECODE(x)) == (x))
60*0Sstevel@tonic-gate #endif	/* __amd64 */
61*0Sstevel@tonic-gate 
62*0Sstevel@tonic-gate void
id32_init(void)63*0Sstevel@tonic-gate id32_init(void)
64*0Sstevel@tonic-gate {
65*0Sstevel@tonic-gate 	id32_arena = vmem_create("id32", NULL, 0, PAGESIZE,
66*0Sstevel@tonic-gate 	    segkmem_alloc, segkmem_free, heap32_arena, 0, VM_SLEEP);
67*0Sstevel@tonic-gate 
68*0Sstevel@tonic-gate 	id32_cache = kmem_cache_create("id32_cache", ID32_ALIGN, ID32_ALIGN,
69*0Sstevel@tonic-gate 	    NULL, NULL, NULL, NULL, id32_arena, 0);
70*0Sstevel@tonic-gate }
71*0Sstevel@tonic-gate 
72*0Sstevel@tonic-gate /*
73*0Sstevel@tonic-gate  * Return a 32-bit identifier for the specified pointer.
74*0Sstevel@tonic-gate  */
75*0Sstevel@tonic-gate uint32_t
id32_alloc(void * ptr,int kmflag)76*0Sstevel@tonic-gate id32_alloc(void *ptr, int kmflag)
77*0Sstevel@tonic-gate {
78*0Sstevel@tonic-gate 	void **hent = kmem_cache_alloc(id32_cache, kmflag);
79*0Sstevel@tonic-gate 	uintptr_t id;
80*0Sstevel@tonic-gate 
81*0Sstevel@tonic-gate 	if (hent == NULL)
82*0Sstevel@tonic-gate 		return (0);
83*0Sstevel@tonic-gate 
84*0Sstevel@tonic-gate 	*hent = ptr;
85*0Sstevel@tonic-gate 	id = ID32_ENCODE((uintptr_t)hent);
86*0Sstevel@tonic-gate 	ASSERT64(id <= UINT32_MAX);
87*0Sstevel@tonic-gate 	return ((uint32_t)id);
88*0Sstevel@tonic-gate }
89*0Sstevel@tonic-gate 
90*0Sstevel@tonic-gate /*
91*0Sstevel@tonic-gate  * Free a 32-bit ID.
92*0Sstevel@tonic-gate  */
93*0Sstevel@tonic-gate void
id32_free(uint32_t id)94*0Sstevel@tonic-gate id32_free(uint32_t id)
95*0Sstevel@tonic-gate {
96*0Sstevel@tonic-gate 	if (!ID32_VALID(id)) {
97*0Sstevel@tonic-gate 		cmn_err(CE_WARN, "id32_free(%x): bad ID rejected\n", id);
98*0Sstevel@tonic-gate 		return;
99*0Sstevel@tonic-gate 	}
100*0Sstevel@tonic-gate 
101*0Sstevel@tonic-gate 	kmem_cache_free(id32_cache, (void *)(uintptr_t)ID32_DECODE(id));
102*0Sstevel@tonic-gate }
103*0Sstevel@tonic-gate 
104*0Sstevel@tonic-gate /*
105*0Sstevel@tonic-gate  * Return the pointer described by a 32-bit ID, or NULL if the ID is bad.
106*0Sstevel@tonic-gate  */
107*0Sstevel@tonic-gate void *
id32_lookup(uint32_t id)108*0Sstevel@tonic-gate id32_lookup(uint32_t id)
109*0Sstevel@tonic-gate {
110*0Sstevel@tonic-gate 	if (!ID32_VALID(id)) {
111*0Sstevel@tonic-gate 		cmn_err(CE_WARN, "id32_lookup(%x): bad ID rejected\n", id);
112*0Sstevel@tonic-gate 		return (NULL);
113*0Sstevel@tonic-gate 	}
114*0Sstevel@tonic-gate 
115*0Sstevel@tonic-gate 	return (((void **)(uintptr_t)ID32_DECODE(id))[0]);
116*0Sstevel@tonic-gate }
117