Re: [PATCH v2 13/13] coresight: trace-id: Add debug & test macros to Trace ID allocation

On 04/07/2022 09:11, Mike Leach wrote:

Adds in a number of pr_debug macros to allow the debugging and test of the trace ID allocation system.

Signed-off-by: Mike Leach mike.leach@linaro.org

.../hwtracing/coresight/coresight-trace-id.c | 33 +++++++++++++++++++ 1 file changed, 33 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c index dac9c89ae00d..841307e0d899 100644 --- a/drivers/hwtracing/coresight/coresight-trace-id.c +++ b/drivers/hwtracing/coresight/coresight-trace-id.c @@ -71,6 +71,27 @@ static int coresight_trace_id_find_new_id(struct coresight_trace_id_map *id_map) return id; } +/* #define TRACE_ID_DEBUG 1 */ +#ifdef TRACE_ID_DEBUG +static void coresight_trace_id_dump_table(struct coresight_trace_id_map *id_map,

• 			  const char *func_name)
  

+{

• /* currently 2 u64s are sufficient to hold all the ids */
• pr_debug("%s id_map::\n", func_name);
• pr_debug("Avial= 0x%016lx%016lx\n", id_map->avail_ids[1], id_map->avail_ids[0]);
• pr_debug("Pend = 0x%016lx%016lx\n", id_map->pend_rel_ids[1], id_map->pend_rel_ids[0]);

minor nit: You may use bitmap_print_to_pagebuf() to print the bitmaps.

+} +#define DUMP_ID_MAP(map) coresight_trace_id_dump_table(map, __func__) +#define DUMP_ID_CPU(cpu, id) pr_debug("%s called; cpu=%d, id=%d\n", __func__, cpu, id) +#define DUMP_ID(id) pr_debug("%s called; id=%d\n", __func__, id) +#define PERF_SESSION(n) pr_debug("%s perf count %d\n", __func__, n) +#else +#define DUMP_ID_MAP(map) +#define DUMP_ID(id) +#define DUMP_ID_CPU(cpu, id) +#define PERF_SESSION(n) +#endif

• /* release all pending IDs for all current maps & clear CPU associations */ static void coresight_trace_id_release_all_pending(void) {

@@ -81,6 +102,7 @@ static void coresight_trace_id_release_all_pending(void) clear_bit(bit, id_map->avail_ids); clear_bit(bit, id_map->pend_rel_ids); }

• DUMP_ID_MAP(id_map);

for_each_possible_cpu(cpu) { if (per_cpu(cpu_ids, cpu).pend_rel) { @@ -126,6 +148,8 @@ static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_ get_cpu_id_out: spin_unlock_irqrestore(&id_map_lock, flags);

• DUMP_ID_CPU(cpu, id);
• DUMP_ID_MAP(id_map); return id; }

@@ -151,6 +175,8 @@ static void coresight_trace_id_map_put_cpu_id(int cpu, struct coresight_trace_id put_cpu_id_out: spin_unlock_irqrestore(&id_map_lock, flags);

• DUMP_ID_CPU(cpu, id);
• DUMP_ID_MAP(id_map); }

static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map) @@ -164,6 +190,8 @@ static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *i coresight_trace_id_set_inuse(id, id_map); spin_unlock_irqrestore(&id_map_lock, flags);

• DUMP_ID(id);
• DUMP_ID_MAP(id_map); return id; }

@@ -174,6 +202,9 @@ static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map * spin_lock_irqsave(&id_map_lock, flags); coresight_trace_id_clear_inuse(id, id_map); spin_unlock_irqrestore(&id_map_lock, flags);

• DUMP_ID(id);
• DUMP_ID_MAP(id_map); }

/* API functions */ @@ -207,6 +238,7 @@ void coresight_trace_id_perf_start(void)

int n;

spin_lock_irqsave(&id_map_lock, flags); perf_cs_etm_session_active++;

n = perf_cs_etm_session_active++;

spin_unlock_irqrestore(&id_map_lock, flags);

PERF_SESSION(n);

Not a good idea to print something from within spin_lock.

} EXPORT_SYMBOL_GPL(coresight_trace_id_perf_start); @@ -217,6 +249,7 @@ void coresight_trace_id_perf_stop(void) spin_lock_irqsave(&id_map_lock, flags); perf_cs_etm_session_active--;

• PERF_SESSION(perf_cs_etm_session_active);

Same as above.

if (!perf_cs_etm_session_active) coresight_trace_id_release_all_pending(); spin_unlock_irqrestore(&id_map_lock, flags);

Suzuki