xref: /openbmc/u-boot/include/trace.h (revision c916075f)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2012 The Chromium OS Authors.
4  */
5 
6 #ifndef __TRACE_H
7 #define __TRACE_H
8 
9 enum {
10 	/*
11 	 * This affects the granularity of our trace. We can bin function
12 	 * entry points into groups on the basis that functions typically
13 	 * have a minimum size, so entry points can't appear any closer
14 	 * than this to each other.
15 	 *
16 	 * The value here assumes a minimum instruction size of 4 bytes,
17 	 * or that instructions are 2 bytes but there are at least 2 of
18 	 * them in every function.
19 	 *
20 	 * Increasing this value reduces the number of functions we can
21 	 * resolve, but reduces the size of the uintptr_t array used for
22 	 * our function list, which is the length of the code divided by
23 	 * this value.
24 	 */
25 	FUNC_SITE_SIZE	= 4,	/* distance between function sites */
26 };
27 
28 enum trace_chunk_type {
29 	TRACE_CHUNK_FUNCS,
30 	TRACE_CHUNK_CALLS,
31 };
32 
33 /* A trace record for a function, as written to the profile output file */
34 struct trace_output_func {
35 	uint32_t offset;		/* Function offset into code */
36 	uint32_t call_count;		/* Number of times called */
37 };
38 
39 /* A header at the start of the trace output buffer */
40 struct trace_output_hdr {
41 	enum trace_chunk_type type;	/* Record type */
42 	uint32_t rec_count;		/* Number of records */
43 };
44 
45 /* Print statistics about traced function calls */
46 void trace_print_stats(void);
47 
48 /**
49  * Dump a list of functions and call counts into a buffer
50  *
51  * Each record in the buffer is a struct trace_func_stats. The 'needed'
52  * parameter returns the number of bytes needed to complete the operation,
53  * which may be more than buff_size if your buffer is too small.
54  *
55  * @param buff		Buffer in which to place data, or NULL to count size
56  * @param buff_size	Size of buffer
57  * @param needed	Returns number of bytes used / needed
58  * @return 0 if ok, -1 on error (buffer exhausted)
59  */
60 int trace_list_functions(void *buff, int buff_size, unsigned *needed);
61 
62 /* Flags for ftrace_record */
63 enum ftrace_flags {
64 	FUNCF_EXIT		= 0UL << 30,
65 	FUNCF_ENTRY		= 1UL << 30,
66 	FUNCF_TEXTBASE		= 2UL << 30,
67 
68 	FUNCF_TIMESTAMP_MASK	= 0x3fffffff,
69 };
70 
71 #define TRACE_CALL_TYPE(call)	((call)->flags & 0xc0000000UL)
72 
73 /* Information about a single function entry/exit */
74 struct trace_call {
75 	uint32_t func;		/* Function offset */
76 	uint32_t caller;	/* Caller function offset */
77 	uint32_t flags;		/* Flags and timestamp */
78 };
79 
80 int trace_list_calls(void *buff, int buff_size, unsigned int *needed);
81 
82 /**
83  * Turn function tracing on and off
84  *
85  * Don't enable trace if it has not been initialised.
86  *
87  * @param enabled	1 to enable trace, 0 to disable
88  */
89 void trace_set_enabled(int enabled);
90 
91 int trace_early_init(void);
92 
93 /**
94  * Init the trace system
95  *
96  * This should be called after relocation with a suitably large buffer
97  * (typically as large as the U-Boot text area)
98  *
99  * @param buff		Pointer to trace buffer
100  * @param buff_size	Size of trace buffer
101  */
102 int trace_init(void *buff, size_t buff_size);
103 
104 #endif
105