iPXE
nx_bitops.h
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1 #ifndef _NX_BITOPS_H
2 #define _NX_BITOPS_H
3 
4 /*
5  * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of the
10  * License, or any later version.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20  * 02110-1301, USA.
21  *
22  * You can also choose to distribute this program under the terms of
23  * the Unmodified Binary Distribution Licence (as given in the file
24  * COPYING.UBDL), provided that you have satisfied its requirements.
25  */
26 
27 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
28 
29 /**
30  * @file
31  *
32  * NetXen bit operations
33  *
34  */
35 
36 /** Datatype used to represent a bit in the pseudo-structures */
37 typedef unsigned char pseudo_bit_t;
38 
39 /**
40  * Wrapper structure for pseudo_bit_t structures
41  *
42  * This structure provides a wrapper around pseudo_bit_t structures.
43  * It has the correct size, and also encapsulates type information
44  * about the underlying pseudo_bit_t-based structure, which allows the
45  * NX_FILL etc. macros to work without requiring explicit type
46  * information.
47  */
48 #define NX_PSEUDO_BIT_STRUCT( _structure ) \
49  union { \
50  uint8_t bytes[ sizeof ( _structure ) / 8 ]; \
51  uint64_t qwords[ sizeof ( _structure ) / 64 ]; \
52  _structure *dummy[0]; \
53  } u;
54 
55 /** Get pseudo_bit_t structure type from wrapper structure pointer */
56 #define NX_PSEUDO_STRUCT( _ptr ) \
57  typeof ( *((_ptr)->u.dummy[0]) )
58 
59 /** Bit offset of a field within a pseudo_bit_t structure */
60 #define NX_BIT_OFFSET( _ptr, _field ) \
61  offsetof ( NX_PSEUDO_STRUCT ( _ptr ), _field )
62 
63 /** Bit width of a field within a pseudo_bit_t structure */
64 #define NX_BIT_WIDTH( _ptr, _field ) \
65  sizeof ( ( ( NX_PSEUDO_STRUCT ( _ptr ) * ) NULL )->_field )
66 
67 /** Qword offset of a field within a pseudo_bit_t structure */
68 #define NX_QWORD_OFFSET( _ptr, _field ) \
69  ( NX_BIT_OFFSET ( _ptr, _field ) / 64 )
70 
71 /** Qword bit offset of a field within a pseudo_bit_t structure
72  *
73  * Yes, using mod-64 would work, but would lose the check for the
74  * error of specifying a mismatched field name and qword index.
75  */
76 #define NX_QWORD_BIT_OFFSET( _ptr, _index, _field ) \
77  ( NX_BIT_OFFSET ( _ptr, _field ) - ( 64 * (_index) ) )
78 
79 /** Bit mask for a field within a pseudo_bit_t structure */
80 #define NX_BIT_MASK( _ptr, _field ) \
81  ( ( ~( ( uint64_t ) 0 ) ) >> \
82  ( 64 - NX_BIT_WIDTH ( _ptr, _field ) ) )
83 
84 /*
85  * Assemble native-endian qword from named fields and values
86  *
87  */
88 
89 #define NX_ASSEMBLE_1( _ptr, _index, _field, _value ) \
90  ( ( ( uint64_t) (_value) ) << \
91  NX_QWORD_BIT_OFFSET ( _ptr, _index, _field ) )
92 
93 #define NX_ASSEMBLE_2( _ptr, _index, _field, _value, ... ) \
94  ( NX_ASSEMBLE_1 ( _ptr, _index, _field, _value ) | \
95  NX_ASSEMBLE_1 ( _ptr, _index, __VA_ARGS__ ) )
96 
97 #define NX_ASSEMBLE_3( _ptr, _index, _field, _value, ... ) \
98  ( NX_ASSEMBLE_1 ( _ptr, _index, _field, _value ) | \
99  NX_ASSEMBLE_2 ( _ptr, _index, __VA_ARGS__ ) )
100 
101 #define NX_ASSEMBLE_4( _ptr, _index, _field, _value, ... ) \
102  ( NX_ASSEMBLE_1 ( _ptr, _index, _field, _value ) | \
103  NX_ASSEMBLE_3 ( _ptr, _index, __VA_ARGS__ ) )
104 
105 #define NX_ASSEMBLE_5( _ptr, _index, _field, _value, ... ) \
106  ( NX_ASSEMBLE_1 ( _ptr, _index, _field, _value ) | \
107  NX_ASSEMBLE_4 ( _ptr, _index, __VA_ARGS__ ) )
108 
109 #define NX_ASSEMBLE_6( _ptr, _index, _field, _value, ... ) \
110  ( NX_ASSEMBLE_1 ( _ptr, _index, _field, _value ) | \
111  NX_ASSEMBLE_5 ( _ptr, _index, __VA_ARGS__ ) )
112 
113 #define NX_ASSEMBLE_7( _ptr, _index, _field, _value, ... ) \
114  ( NX_ASSEMBLE_1 ( _ptr, _index, _field, _value ) | \
115  NX_ASSEMBLE_6 ( _ptr, _index, __VA_ARGS__ ) )
116 
117 /*
118  * Build native-endian (positive) qword bitmasks from named fields
119  *
120  */
121 
122 #define NX_MASK_1( _ptr, _index, _field ) \
123  ( NX_BIT_MASK ( _ptr, _field ) << \
124  NX_QWORD_BIT_OFFSET ( _ptr, _index, _field ) )
125 
126 #define NX_MASK_2( _ptr, _index, _field, ... ) \
127  ( NX_MASK_1 ( _ptr, _index, _field ) | \
128  NX_MASK_1 ( _ptr, _index, __VA_ARGS__ ) )
129 
130 #define NX_MASK_3( _ptr, _index, _field, ... ) \
131  ( NX_MASK_1 ( _ptr, _index, _field ) | \
132  NX_MASK_2 ( _ptr, _index, __VA_ARGS__ ) )
133 
134 #define NX_MASK_4( _ptr, _index, _field, ... ) \
135  ( NX_MASK_1 ( _ptr, _index, _field ) | \
136  NX_MASK_3 ( _ptr, _index, __VA_ARGS__ ) )
137 
138 #define NX_MASK_5( _ptr, _index, _field, ... ) \
139  ( NX_MASK_1 ( _ptr, _index, _field ) | \
140  NX_MASK_4 ( _ptr, _index, __VA_ARGS__ ) )
141 
142 #define NX_MASK_6( _ptr, _index, _field, ... ) \
143  ( NX_MASK_1 ( _ptr, _index, _field ) | \
144  NX_MASK_5 ( _ptr, _index, __VA_ARGS__ ) )
145 
146 #define NX_MASK_7( _ptr, _index, _field, ... ) \
147  ( NX_MASK_1 ( _ptr, _index, _field ) | \
148  NX_MASK_6 ( _ptr, _index, __VA_ARGS__ ) )
149 
150 /*
151  * Populate big-endian qwords from named fields and values
152  *
153  */
154 
155 #define NX_FILL( _ptr, _index, _assembled ) \
156  do { \
157  uint64_t *__ptr = &(_ptr)->u.qwords[(_index)]; \
158  uint64_t __assembled = (_assembled); \
159  *__ptr = cpu_to_le64 ( __assembled ); \
160  } while ( 0 )
161 
162 #define NX_FILL_1( _ptr, _index, ... ) \
163  NX_FILL ( _ptr, _index, NX_ASSEMBLE_1 ( _ptr, _index, __VA_ARGS__ ) )
164 
165 #define NX_FILL_2( _ptr, _index, ... ) \
166  NX_FILL ( _ptr, _index, NX_ASSEMBLE_2 ( _ptr, _index, __VA_ARGS__ ) )
167 
168 #define NX_FILL_3( _ptr, _index, ... ) \
169  NX_FILL ( _ptr, _index, NX_ASSEMBLE_3 ( _ptr, _index, __VA_ARGS__ ) )
170 
171 #define NX_FILL_4( _ptr, _index, ... ) \
172  NX_FILL ( _ptr, _index, NX_ASSEMBLE_4 ( _ptr, _index, __VA_ARGS__ ) )
173 
174 #define NX_FILL_5( _ptr, _index, ... ) \
175  NX_FILL ( _ptr, _index, NX_ASSEMBLE_5 ( _ptr, _index, __VA_ARGS__ ) )
176 
177 #define NX_FILL_6( _ptr, _index, ... ) \
178  NX_FILL ( _ptr, _index, NX_ASSEMBLE_6 ( _ptr, _index, __VA_ARGS__ ) )
179 
180 #define NX_FILL_7( _ptr, _index, ... ) \
181  NX_FILL ( _ptr, _index, NX_ASSEMBLE_7 ( _ptr, _index, __VA_ARGS__ ) )
182 
183 /** Extract value of named field */
184 #define NX_GET64( _ptr, _field ) \
185  ( { \
186  unsigned int __index = NX_QWORD_OFFSET ( _ptr, _field ); \
187  uint64_t *__ptr = &(_ptr)->u.qwords[__index]; \
188  uint64_t __value = le64_to_cpu ( *__ptr ); \
189  __value >>= \
190  NX_QWORD_BIT_OFFSET ( _ptr, __index, _field ); \
191  __value &= NX_BIT_MASK ( _ptr, _field ); \
192  __value; \
193  } )
194 
195 /** Extract value of named field (for fields up to the size of a long) */
196 #define NX_GET( _ptr, _field ) \
197  ( ( unsigned long ) NX_GET64 ( _ptr, _field ) )
198 
199 #endif /* _NX_BITOPS_H */
pseudo_bit_t
unsigned char pseudo_bit_t
Datatype used to represent a bit in the pseudo-structures.
Definition: nx_bitops.h:37
FILE_LICENCE
FILE_LICENCE(GPL2_OR_LATER_OR_UBDL)
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