1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#ifndef _SYS_GMON_H_
33#define _SYS_GMON_H_
34
35#include <machine/profile.h>
36
37/*
38 * Structure prepended to gmon.out profiling data file.
39 */
40struct gmonhdr {
41 u_long lpc; /* base pc address of sample buffer */
42 u_long hpc; /* max pc address of sampled buffer */
43 int ncnt; /* size of sample buffer (plus this header) */
44 int version; /* version number */
45 int profrate; /* profiling clock rate */
46 int histcounter_type; /* size (in bits) and sign of HISTCOUNTER */
47 int spare[2]; /* reserved */
48};
49#define GMONVERSION 0x00051879
50
51/*
52 * Type of histogram counters used in the kernel.
53 */
54#ifdef GPROF4
55#define HISTCOUNTER int64_t
56#else
57#define HISTCOUNTER unsigned short
58#endif
59
60/*
61 * Fraction of text space to allocate for histogram counters.
62 * We allocate counters at the same or higher density as function
63 * addresses, so that each counter belongs to a unique function.
64 * A lower density of counters would give less resolution but a
65 * higher density would be wasted.
66 */
67#define HISTFRACTION (FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER) == 0 \
68 ? 1 : FUNCTION_ALIGNMENT / sizeof(HISTCOUNTER))
69
70/*
71 * Fraction of text space to allocate for from hash buckets.
72 * The value of HASHFRACTION is based on the minimum number of bytes
73 * of separation between two subroutine call points in the object code.
74 * Given MIN_SUBR_SEPARATION bytes of separation the value of
75 * HASHFRACTION is calculated as:
76 *
77 * HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof(short) - 1);
78 *
79 * For example, on the VAX, the shortest two call sequence is:
80 *
81 * calls $0,(r0)
82 * calls $0,(r0)
83 *
84 * which is separated by only three bytes, thus HASHFRACTION is
85 * calculated as:
86 *
87 * HASHFRACTION = 3 / (2 * 2 - 1) = 1
88 *
89 * Note that the division above rounds down, thus if MIN_SUBR_FRACTION
90 * is less than three, this algorithm will not work!
91 *
92 * In practice, however, call instructions are rarely at a minimal
93 * distance. Hence, we will define HASHFRACTION to be 2 across all
94 * architectures. This saves a reasonable amount of space for
95 * profiling data structures without (in practice) sacrificing
96 * any granularity.
97 */
98/*
99 * XXX I think the above analysis completely misses the point. I think
100 * the point is that addresses in different functions must hash to
101 * different values. Since the hash is essentially division by
102 * sizeof(unsigned short), the correct formula is:
103 *
104 * HASHFRACTION = MIN_FUNCTION_ALIGNMENT / sizeof(unsigned short)
105 *
106 * Note that he unsigned short here has nothing to do with the one for
107 * HISTFRACTION.
108 *
109 * Hash collisions from a two call sequence don't matter. They get
110 * handled like collisions for calls to different addresses from the
111 * same address through a function pointer.
112 */
113#define HASHFRACTION (FUNCTION_ALIGNMENT / sizeof(unsigned short) == 0 \
114 ? 1 : FUNCTION_ALIGNMENT / sizeof(unsigned short))
115
116/*
117 * percent of text space to allocate for tostructs with a minimum.
118 */
119#define ARCDENSITY 2
120#define MINARCS 50
121
122/*
123 * Limit on the number of arcs to so that arc numbers can be stored in
124 * `*froms' and stored and incremented without overflow in links.
125 */
126#define MAXARCS (((u_long)1 << (8 * sizeof(u_short))) - 2)
127
128struct tostruct {
129 u_long selfpc;
130 long count;
131 u_short link;
132 u_short pad;
133};
134
135/*
136 * a raw arc, with pointers to the calling site and
137 * the called site and a count.
138 */
139struct rawarc {
140 u_long raw_frompc;
141 u_long raw_selfpc;
142 long raw_count;
143};
144
145/*
146 * general rounding functions.
147 */
148#define ROUNDDOWN(x,y) rounddown(x,y)
149#define ROUNDUP(x,y) roundup(x,y)
150
151/*
152 * The profiling data structures are housed in this structure.
153 */
154struct gmonparam {
155 int state;
156 HISTCOUNTER *kcount;
157 u_long kcountsize;
158 u_short *froms;
159 u_long fromssize;
160 struct tostruct *tos;
161 u_long tossize;
162 long tolimit;
163 uintfptr_t lowpc;
164 uintfptr_t highpc;
165 u_long textsize;
166 u_long hashfraction;
167 int profrate; /* XXX wrong type to match gmonhdr */
168 HISTCOUNTER *cputime_count;
169 int cputime_overhead;
170 HISTCOUNTER *mcount_count;
171 int mcount_overhead;
172 int mcount_post_overhead;
173 int mcount_pre_overhead;
174 HISTCOUNTER *mexitcount_count;
175 int mexitcount_overhead;
176 int mexitcount_post_overhead;
177 int mexitcount_pre_overhead;
178 int histcounter_type;
179};
180extern struct gmonparam _gmonparam;
181
182/*
183 * Possible states of profiling.
184 */
185#define GMON_PROF_ON 0
186#define GMON_PROF_BUSY 1
187#define GMON_PROF_ERROR 2
188#define GMON_PROF_OFF 3
189#define GMON_PROF_HIRES 4
190
191/*
192 * Sysctl definitions for extracting profiling information from the kernel.
193 */
194#define GPROF_STATE 0 /* int: profiling enabling variable */
195#define GPROF_COUNT 1 /* struct: profile tick count buffer */
196#define GPROF_FROMS 2 /* struct: from location hash bucket */
197#define GPROF_TOS 3 /* struct: destination/count structure */
198#define GPROF_GMONPARAM 4 /* struct: profiling parameters (see above) */
199
200#ifdef _KERNEL
201
202#define KCOUNT(p,index) \
203 ((p)->kcount[(index) / (HISTFRACTION * sizeof(HISTCOUNTER))])
204#define PC_TO_I(p, pc) ((uintfptr_t)(pc) - (uintfptr_t)(p)->lowpc)
205
206#ifdef GUPROF
207
208#define CALIB_SCALE 1000
209
210extern int cputime_bias;
211
212int cputime(void);
213void nullfunc_loop_profiled(void);
214void nullfunc_profiled(void);
215void startguprof(struct gmonparam *p);
216void stopguprof(struct gmonparam *p);
217
218#else /* !GUPROF */
219
220#define startguprof(p)
221#define stopguprof(p)
222
223#endif /* GUPROF */
224
225void empty_loop(void);
226void kmupetext(uintfptr_t nhighpc);
227void mexitcount(uintfptr_t selfpc);
228void nullfunc(void);
229void nullfunc_loop(void);
230
231#else /* !_KERNEL */
232
233#include <sys/cdefs.h>
234
235__BEGIN_DECLS
236void moncontrol(int);
237void monstartup(u_long, u_long);
238__END_DECLS
239
240#endif /* _KERNEL */
241
242#endif /* !_SYS_GMON_H_ */