From b2e16a85a1fa3f871ca73a554a7fd63067d9ad14 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Tue, 11 Jun 2013 11:14:39 -0700 Subject: Add trace library Add a library which supports tracing of execution using built-in gcc features and a microsecond timer. This can be used to record a list of function which are executed, along with a timestamp for each. Later this information can be sent to the host for processing. Signed-off-by: Simon Glass --- include/common.h | 4 ++ include/trace.h | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 129 insertions(+) create mode 100644 include/trace.h (limited to 'include') diff --git a/include/common.h b/include/common.h index 126891d..e5220cf 100644 --- a/include/common.h +++ b/include/common.h @@ -750,6 +750,10 @@ void irq_install_handler(int, interrupt_handler_t *, void *); void irq_free_handler (int); void reset_timer (void); ulong get_timer (ulong base); + +/* Return value of monotonic microsecond timer */ +unsigned long timer_get_us(void); + void enable_interrupts (void); int disable_interrupts (void); diff --git a/include/trace.h b/include/trace.h new file mode 100644 index 0000000..8082466 --- /dev/null +++ b/include/trace.h @@ -0,0 +1,125 @@ +/* + * Copyright (c) 2012 The Chromium OS Authors. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#ifndef __TRACE_H +#define __TRACE_H + +enum { + /* + * This affects the granularity of our trace. We can bin function + * entry points into groups on the basis that functions typically + * have a minimum size, so entry points can't appear any closer + * than this to each other. + * + * The value here assumes a minimum instruction size of 4 bytes, + * or that instructions are 2 bytes but there are at least 2 of + * them in every function. + * + * Increasing this value reduces the number of functions we can + * resolve, but reduces the size of the uintptr_t array used for + * our function list, which is the length of the code divided by + * this value. + */ + FUNC_SITE_SIZE = 4, /* distance between function sites */ +}; + +enum trace_chunk_type { + TRACE_CHUNK_FUNCS, + TRACE_CHUNK_CALLS, +}; + +/* A trace record for a function, as written to the profile output file */ +struct trace_output_func { + uint32_t offset; /* Function offset into code */ + uint32_t call_count; /* Number of times called */ +}; + +/* A header at the start of the trace output buffer */ +struct trace_output_hdr { + enum trace_chunk_type type; /* Record type */ + uint32_t rec_count; /* Number of records */ +}; + +/* Print statistics about traced function calls */ +void trace_print_stats(void); + +/** + * Dump a list of functions and call counts into a buffer + * + * Each record in the buffer is a struct trace_func_stats. The 'needed' + * parameter returns the number of bytes needed to complete the operation, + * which may be more than buff_size if your buffer is too small. + * + * @param buff Buffer in which to place data, or NULL to count size + * @param buff_size Size of buffer + * @param needed Returns number of bytes used / needed + * @return 0 if ok, -1 on error (buffer exhausted) + */ +int trace_list_functions(void *buff, int buff_size, unsigned *needed); + +/* Flags for ftrace_record */ +enum ftrace_flags { + FUNCF_EXIT = 0UL << 30, + FUNCF_ENTRY = 1UL << 30, + FUNCF_TEXTBASE = 2UL << 30, + + FUNCF_TIMESTAMP_MASK = 0x3fffffff, +}; + +#define TRACE_CALL_TYPE(call) ((call)->flags & 0xc0000000UL) + +/* Information about a single function entry/exit */ +struct trace_call { + uint32_t func; /* Function offset */ + uint32_t caller; /* Caller function offset */ + uint32_t flags; /* Flags and timestamp */ +}; + +int trace_list_calls(void *buff, int buff_size, unsigned int *needed); + +/** + * Turn function tracing on and off + * + * Don't enable trace if it has not been initialised. + * + * @param enabled 1 to enable trace, 0 to disable + */ +void trace_set_enabled(int enabled); + +#ifdef CONFIG_TRACE_EARLY +int trace_early_init(void); +#else +static inline int trace_early_init(void) +{ + return 0; +} +#endif + +/** + * Init the trace system + * + * This should be called after relocation with a suitably large buffer + * (typically as large as the U-Boot text area) + * + * @param buff Pointer to trace buffer + * @param buff_size Size of trace buffer + */ +int trace_init(void *buff, size_t buff_size); + +#endif -- cgit v1.1