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

From: Suzuki K Poulose
Date: Wed Jul 20 2022 - 05:41:09 EST


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@xxxxxxxxxx>
---
.../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