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      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