xref: /illumos-gate/usr/src/uts/intel/asm/bitmap.h (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
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 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
26  */
27 
28 #ifndef _ASM_BITMAP_H
29 #define	_ASM_BITMAP_H
30 
31 #include <sys/ccompile.h>
32 #include <sys/types.h>
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 #if !defined(__lint) && defined(__GNUC__)
39 
40 #if defined(__amd64)
41 #define	__SUF	"q"
42 #elif defined(__i386)
43 #define	__SUF	"l"
44 #else
45 #error "port me"
46 #endif
47 
48 extern __GNU_INLINE int
49 highbit(ulong_t i)
50 {
51 	long value;
52 	uint8_t zf;
53 
54 	__asm__(
55 	    "bsr" __SUF " %2,%0;"
56 	    "setz %1"
57 	    : "=r" (value), "=q" (zf)
58 	    : "mr" (i)
59 	    : "cc");
60 
61 	return (zf ? 0 : (value + 1));
62 }
63 
64 extern __GNU_INLINE int
65 lowbit(ulong_t i)
66 {
67 	long value;
68 	uint8_t zf;
69 
70 	__asm__(
71 	    "bsf" __SUF " %2,%0;"
72 	    "setz %1"
73 	    : "=r" (value), "=q" (zf)
74 	    : "mr" (i)
75 	    : "cc");
76 
77 	return (zf ? 0 : (value + 1));
78 }
79 
80 extern __GNU_INLINE uint_t
81 atomic_btr32(uint32_t *memory, uint_t bitnum)
82 {
83 	uint8_t value;
84 
85 	__asm__ __volatile__(
86 	    "lock;"
87 	    "btrl %2,%0;"
88 	    "setc %1"
89 	    : "+m" (*memory), "=r" (value)
90 	    : "ir" (bitnum)
91 	    : "cc");
92 
93 	return ((uint_t)value);
94 }
95 
96 #undef __SUF
97 
98 #endif	/* !__lint && __GNUC__ */
99 
100 #ifdef	__cplusplus
101 }
102 #endif
103 
104 #endif	/* _ASM_BITMAP_H */
105