Implement a 'trace wipe' command to delete the currently accumulated trace data. This comes handy when someone needs to trace a particular command. For example:

=> trace pause; trace wipe => trace resume; dhcp; trace pause => trace stats => trace calls 0x02100000 0x10000000 => tftpput $profbase $profoffset 192.168.0.16:trace.bin

Signed-off-by: Jerome Forissier jerome.forissier@linaro.org --- cmd/trace.c | 5 +++++ include/trace.h | 2 ++ lib/trace.c | 47 +++++++++++++++++++++++++++++++++-------------- 3 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/cmd/trace.c b/cmd/trace.c index 937e6a682ad..d36008720db 100644 --- a/cmd/trace.c +++ b/cmd/trace.c @@ -100,6 +100,10 @@ int do_trace(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) case 's': trace_print_stats(); break; + case 'w': + if (trace_wipe()) + return CMD_RET_FAILURE; + break; default: return CMD_RET_USAGE; } @@ -113,6 +117,7 @@ U_BOOT_CMD( "stats - display tracing statistics\n" "trace pause - pause tracing\n" "trace resume - resume tracing\n" + "trace wipe - wipe traces\n" "trace funclist [<addr> <size>] - dump function list into buffer\n" "trace calls [<addr> <size>] " "- dump function call trace into buffer" diff --git a/include/trace.h b/include/trace.h index 763d6d1255a..782eaae2fc2 100644 --- a/include/trace.h +++ b/include/trace.h @@ -100,6 +100,8 @@ void trace_set_enabled(int enabled);

int trace_early_init(void);

+int trace_clear(void); + /** * Init the trace system * diff --git a/lib/trace.c b/lib/trace.c index cabbe47b58a..def9f912c92 100644 --- a/lib/trace.c +++ b/lib/trace.c @@ -351,14 +351,8 @@ static int get_func_count(void) return gd->mon_len / FUNC_SITE_SIZE; }

-/** - * trace_init() - initialize the tracing system and enable it - * - * @buff: Pointer to trace buffer - * @buff_size: Size of trace buffer - * Return: 0 if ok - */ -int notrace trace_init(void *buff, size_t buff_size) +static int notrace trace_init_(void *buff, size_t buff_size, bool copy_early, + bool enable) { int func_count = get_func_count(); size_t needed; @@ -368,7 +362,7 @@ int notrace trace_init(void *buff, size_t buff_size) return func_count; trace_save_gd();

- if (!was_disabled) { + if (copy_early) { #ifdef CONFIG_TRACE_EARLY ulong used, count; char *end; @@ -394,9 +388,6 @@ int notrace trace_init(void *buff, size_t buff_size) } puts("\n"); memcpy(buff, hdr, used); -#else - puts("trace: already enabled\n"); - return -EALREADY; #endif } hdr = (struct trace_hdr *)buff; @@ -419,13 +410,41 @@ int notrace trace_init(void *buff, size_t buff_size) hdr->ftrace_size = (buff_size - needed) / sizeof(*hdr->ftrace); hdr->depth_limit = CONFIG_TRACE_CALL_DEPTH_LIMIT;

- puts("trace: enabled\n"); - trace_enabled = 1; + printf("trace: initialized, %senabled\n", enable ? "" : "not "); + trace_enabled = enable; trace_inited = 1;

return 0; }

+/** + * trace_init() - initialize the tracing system and enable it + * + * @buff: Pointer to trace buffer + * @buff_size: Size of trace buffer + * Return: 0 if ok + */ +int notrace trace_init(void *buff, size_t buff_size) +{ + /* If traces are enabled already, we may have early traces to copy */ + return trace_init_(buff, buff_size, trace_enabled, true); +} + +/** + * trace_clear() - clear accumulated traced data + * + * May be called with tracing enabled or disabled. + */ +int notrace trace_clear(void) +{ + bool was_enabled = trace_enabled; + + if (trace_enabled) + trace_enabled = 0; + return trace_init_(gd->trace_buff, CONFIG_TRACE_BUFFER_SIZE, + false, was_enabled); +} + #ifdef CONFIG_TRACE_EARLY /** * trace_early_init() - initialize the tracing system for early tracing

Test the newly added 'trace wipe' command.

Signed-off-by: Jerome Forissier jerome.forissier@linaro.org Acked-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- test/py/tests/test_trace.py | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)

diff --git a/test/py/tests/test_trace.py b/test/py/tests/test_trace.py index ec1e624722c..44239da5280 100644 --- a/test/py/tests/test_trace.py +++ b/test/py/tests/test_trace.py @@ -70,6 +70,32 @@ def collect_trace(cons): return fname, int(dm_f_time[0])

+def wipe_and_collect_trace(cons): + """Pause and wipe traces, return the number of calls (should be zero) + + Args: + cons (ConsoleBase): U-Boot console + + Returns: + int: the number of traced function calls reported by 'trace stats' + """ + cons.run_command('trace pause') + cons.run_command('trace wipe') + out = cons.run_command('trace stats') + + # The output is something like this: + # 117,221 function sites + # 0 function calls + # 0 untracked function calls + # 0 traced function calls + + # Get a dict of values from the output + lines = [line.split(maxsplit=1) for line in out.splitlines() if line] + vals = {key: val.replace(',', '') for val, key in lines} + + return int(vals['traced function calls']) + + def check_function(cons, fname, proftool, map_fname, trace_dat): """Check that the 'function' output works

@@ -304,3 +330,7 @@ def test_trace(u_boot_console): # This allows for CI being slow to run diff = abs(fg_time - dm_f_time) assert diff / dm_f_time < 0.3 + + # Check that the trace buffer can be wiped + numcalls = wipe_and_collect_trace(cons) + assert numcalls == 0