FD.io VPP  v20.05.1-5-g09f167997
Vector Packet Processing
clib.h
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1 /*
2  * Copyright (c) 2015 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 /*
16  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus
17 
18  Permission is hereby granted, free of charge, to any person obtaining
19  a copy of this software and associated documentation files (the
20  "Software"), to deal in the Software without restriction, including
21  without limitation the rights to use, copy, modify, merge, publish,
22  distribute, sublicense, and/or sell copies of the Software, and to
23  permit persons to whom the Software is furnished to do so, subject to
24  the following conditions:
25 
26  The above copyright notice and this permission notice shall be
27  included in all copies or substantial portions of the Software.
28 
29  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
30  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
31  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
32  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
33  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
34  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
35  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
36 */
37 
38 #ifndef included_clib_h
39 #define included_clib_h
40 
41 #include <vppinfra/config.h>
42 
43 #ifdef __x86_64__
44 #include <x86intrin.h>
45 #endif
46 
47 /* Standalone means to not assume we are running on a Unix box. */
48 #if ! defined (CLIB_STANDALONE) && ! defined (CLIB_LINUX_KERNEL)
49 #define CLIB_UNIX
50 #endif
51 
52 #include <vppinfra/types.h>
53 #include <vppinfra/atomics.h>
54 
55 /* Global DEBUG flag. Setting this to 1 or 0 turns off
56  ASSERT (see vppinfra/error.h) & other debugging code. */
57 #ifndef CLIB_DEBUG
58 #define CLIB_DEBUG 0
59 #endif
60 
61 #ifndef NULL
62 #define NULL ((void *) 0)
63 #endif
64 
65 #define BITS(x) (8*sizeof(x))
66 #define ARRAY_LEN(x) (sizeof (x)/sizeof (x[0]))
67 
68 #define _STRUCT_FIELD(t,f) (((t *) 0)->f)
69 #define STRUCT_OFFSET_OF(t,f) ((uword) & _STRUCT_FIELD (t, f))
70 #define STRUCT_BIT_OFFSET_OF(t,f) (BITS(u8) * (uword) & _STRUCT_FIELD (t, f))
71 #define STRUCT_SIZE_OF(t,f) (sizeof (_STRUCT_FIELD (t, f)))
72 #define STRUCT_BITS_OF(t,f) (BITS (_STRUCT_FIELD (t, f)))
73 #define STRUCT_ARRAY_LEN(t,f) ARRAY_LEN (_STRUCT_FIELD (t, f))
74 #define STRUCT_MARK(mark) u8 mark[0]
75 #define STRUCT_MARK_PTR(v, f) &(v)->f
76 
77 /* Stride in bytes between struct array elements. */
78 #define STRUCT_STRIDE_OF(t,f) \
79  ( ((uword) & (((t *) 0)[1].f)) \
80  - ((uword) & (((t *) 0)[0].f)))
81 
82 #define STRUCT_OFFSET_OF_VAR(v,f) ((uword) (&(v)->f) - (uword) (v))
83 
84 /* Used to pack structure elements. */
85 #define CLIB_PACKED(x) x __attribute__ ((packed))
86 #define CLIB_UNUSED(x) x __attribute__ ((unused))
87 
88 /* similar to CLIB_CACHE_LINE_ALIGN_MARK() but with arbitrary alignment */
89 #define CLIB_ALIGN_MARK(name, alignment) u8 name[0] __attribute__((aligned(alignment)))
90 
91 /* Make a string from the macro's argument */
92 #define CLIB_STRING_MACRO(x) #x
93 
94 #define __clib_unused __attribute__ ((unused))
95 #define __clib_weak __attribute__ ((weak))
96 #define __clib_packed __attribute__ ((packed))
97 #define __clib_constructor __attribute__ ((constructor))
98 #define __clib_noinline __attribute__ ((noinline))
99 #define __clib_aligned(x) __attribute__ ((aligned(x)))
100 #define __clib_section(s) __attribute__ ((section(s)))
101 
102 #define never_inline __attribute__ ((__noinline__))
103 
104 #if CLIB_DEBUG > 0
105 #define always_inline static inline
106 #define static_always_inline static inline
107 #else
108 #define always_inline static inline __attribute__ ((__always_inline__))
109 #define static_always_inline static inline __attribute__ ((__always_inline__))
110 #endif
111 
112 
113 /* Reserved (unused) structure element with address offset between
114  from and to. */
115 #define CLIB_PAD_FROM_TO(from,to) u8 pad_##from[(to) - (from)]
116 
117 /* Hints to compiler about hot/cold code. */
118 #define PREDICT_FALSE(x) __builtin_expect((x),0)
119 #define PREDICT_TRUE(x) __builtin_expect((x),1)
120 
121 /*
122  * Compiler barrier
123  * prevent compiler to reorder memory access accross this boundary
124  * prevent compiler to cache values in register (force reload)
125  * Not to be confused with CPU memory barrier below
126  */
127 #define CLIB_COMPILER_BARRIER() asm volatile ("":::"memory")
128 
129 /* Full memory barrier (read and write). */
130 #define CLIB_MEMORY_BARRIER() __sync_synchronize ()
131 
132 #if __x86_64__
133 #define CLIB_MEMORY_STORE_BARRIER() __builtin_ia32_sfence ()
134 #else
135 #define CLIB_MEMORY_STORE_BARRIER() __sync_synchronize ()
136 #endif
137 
138 /* Arranges for function to be called before main. */
139 #define INIT_FUNCTION(decl) \
140  decl __attribute ((constructor)); \
141  decl
142 
143 /* Arranges for function to be called before exit. */
144 #define EXIT_FUNCTION(decl) \
145  decl __attribute ((destructor)); \
146  decl
147 
148 /* Use __builtin_clz if available. */
149 #if uword_bits == 64
150 #define count_leading_zeros(x) __builtin_clzll (x)
151 #define count_trailing_zeros(x) __builtin_ctzll (x)
152 #else
153 #define count_leading_zeros(x) __builtin_clzl (x)
154 #define count_trailing_zeros(x) __builtin_ctzl (x)
155 #endif
156 
157 #if defined (count_leading_zeros)
160 {
161  uword n;
162  n = count_leading_zeros (x);
163  return BITS (uword) - n - 1;
164 }
165 #else
167 min_log2 (uword x)
168 {
169  uword a = x, b = BITS (uword) / 2, c = 0, r = 0;
170 
171  /* Reduce x to 4 bit result. */
172 #define _ \
173 { \
174  c = a >> b; \
175  if (c) a = c; \
176  if (c) r += b; \
177  b /= 2; \
178 }
179 
180  if (BITS (uword) > 32)
181  _;
182  _;
183  _;
184  _;
185 #undef _
186 
187  /* Do table lookup on 4 bit partial. */
188  if (BITS (uword) > 32)
189  {
190  const u64 table = 0x3333333322221104LL;
191  uword t = (table >> (4 * a)) & 0xf;
192  r = t < 4 ? r + t : ~0;
193  }
194  else
195  {
196  const u32 table = 0x22221104;
197  uword t = (a & 8) ? 3 : ((table >> (4 * a)) & 0xf);
198  r = t < 4 ? r + t : ~0;
199  }
200 
201  return r;
202 }
203 #endif
204 
207 {
208  uword l = min_log2 (x);
209  if (x > ((uword) 1 << l))
210  l++;
211  return l;
212 }
213 
216 {
217  if (BITS (uword) == 64)
218  return min_log2 (x);
219  else
220  {
221  uword l, y;
222  y = x;
223  l = 0;
224  if (y == 0)
225  {
226  l += 32;
227  x >>= 32;
228  }
229  l += min_log2 (x);
230  return l;
231  }
232 }
233 
236 {
237  return ((uword) 1 << x) - (uword) 1;
238 }
239 
242 {
243  word y = (word) 1 << min_log2 (x);
244  if (x > y)
245  y *= 2;
246  return y;
247 }
248 
251 {
252  return 0 == (x & (x - 1));
253 }
254 
257 {
258  return (x + pow2 - 1) & ~(pow2 - 1);
259 }
260 
263 {
264  return (x + pow2 - 1) & ~(pow2 - 1);
265 }
266 
269 {
270  return x & -x;
271 }
272 
275 {
276  uword result;
277 #ifdef count_trailing_zeros
278  result = count_trailing_zeros (x);
279 #else
280  result = min_log2 (first_set (x));
281 #endif
282  return result;
283 }
284 
287 {
288  return (int) x;
289 }
290 
293 {
294  return (word) (x + .5);
295 }
296 
299 {
300  return f * flt_round_nearest (x / f);
301 }
302 
304 extract_bits (uword x, int start, int count)
305 {
306 #ifdef __BMI__
307  return _bextr_u64 (x, start, count);
308 #endif
309  return (x >> start) & pow2_mask (count);
310 }
311 
312 #define clib_max(x,y) \
313 ({ \
314  __typeof__ (x) _x = (x); \
315  __typeof__ (y) _y = (y); \
316  _x > _y ? _x : _y; \
317 })
318 
319 #define clib_min(x,y) \
320 ({ \
321  __typeof__ (x) _x = (x); \
322  __typeof__ (y) _y = (y); \
323  _x < _y ? _x : _y; \
324 })
325 
326 #define clib_abs(x) \
327 ({ \
328  __typeof__ (x) _x = (x); \
329  _x < 0 ? -_x : _x; \
330 })
331 
332 /* Standard standalone-only function declarations. */
333 #ifndef CLIB_UNIX
334 void clib_standalone_init (void *memory, uword memory_bytes);
335 
336 void qsort (void *base, uword n, uword size,
337  int (*)(const void *, const void *));
338 #endif
339 
340 /* Stack backtrace. */
341 uword
342 clib_backtrace (uword * callers, uword max_callers, uword n_frames_to_skip);
343 
344 #endif /* included_clib_h */
345 
346 /*
347  * fd.io coding-style-patch-verification: ON
348  *
349  * Local Variables:
350  * eval: (c-set-style "gnu")
351  * End:
352  */
u8 count
Definition: dhcp.api:208
vhost_user_memory_t memory
Definition: vhost_user.h:255
a
Definition: bitmap.h:538
static uword log2_first_set(uword x)
Definition: clib.h:274
#define count_leading_zeros(x)
Definition: clib.h:153
unsigned long u64
Definition: types.h:89
#define count_trailing_zeros(x)
Definition: clib.h:154
static uword min_log2(uword x)
Definition: clib.h:159
double f64
Definition: types.h:142
i64 word
Definition: types.h:111
#define always_inline
Definition: clib.h:105
static uword pow2_mask(uword x)
Definition: clib.h:235
unsigned int u32
Definition: types.h:88
static u64 min_log2_u64(u64 x)
Definition: clib.h:215
uword clib_backtrace(uword *callers, uword max_callers, uword n_frames_to_skip)
Definition: backtrace.c:226
svmdb_client_t * c
static f64 flt_round_to_multiple(f64 x, f64 f)
Definition: clib.h:298
static uword max_pow2(uword x)
Definition: clib.h:241
static u64 round_pow2_u64(u64 x, u64 pow2)
Definition: clib.h:262
static uword round_pow2(uword x, uword pow2)
Definition: clib.h:256
static uword first_set(uword x)
Definition: clib.h:268
static uword is_pow2(uword x)
Definition: clib.h:250
static uword extract_bits(uword x, int start, int count)
Definition: clib.h:304
static word flt_round_nearest(f64 x)
Definition: clib.h:292
void qsort(void *base, uword n, uword size, int(*compar)(const void *, const void *))
Definition: qsort.c:56
static uword max_log2(uword x)
Definition: clib.h:206
u64 uword
Definition: types.h:112
static f64 flt_round_down(f64 x)
Definition: clib.h:286
#define BITS(x)
Definition: clib.h:65