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