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

=> trace clear; 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 | 13 ++++++++++++- include/trace.h | 2 ++ lib/trace.c | 47 +++++++++++++++++++++++++++++++++-------------- 3 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/cmd/trace.c b/cmd/trace.c index 937e6a682ad..e95ac7ca9da 100644 --- a/cmd/trace.c +++ b/cmd/trace.c @@ -87,8 +87,18 @@ int do_trace(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) trace_set_enabled(0); break; case 'c': - if (create_call_list(argc, argv)) + switch (*(cmd + 1)) { + case 'a': + if (create_call_list(argc, argv)) + return cmd_usage(cmdtp); + break; + case 'l': + if (trace_clear()) + return CMD_RET_FAILURE; + break; + default: return cmd_usage(cmdtp); + } break; case 'r': trace_set_enabled(1); @@ -113,6 +123,7 @@ U_BOOT_CMD( "stats - display tracing statistics\n" "trace pause - pause tracing\n" "trace resume - resume tracing\n" + "trace clear - clear 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