firewire: core: add tracepoints event for self_id_sequence

It is helpful to trace the content of self ID sequence when the core
function building bus topology.

This commit adds a tracepoints event fot the purpose. It seems not to
achieve printing variable length of array in print time without any
storage, thus the structure of event includes a superfluous array to store
the state of port. Additionally, there is no helper function to print
symbol array, thus the state of port is printed as raw value.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Takashi Sakamoto <[e-mail]>

drivers/firewire/core-topology.c

···
  * internally consistent.  On success this function returns the
  * fw_node corresponding to the local card otherwise NULL.
  */
-static struct fw_node *build_tree(struct fw_card *card, const u32 *sid, int self_id_count)
+static struct fw_node *build_tree(struct fw_card *card, const u32 *sid, int self_id_count,
+				  unsigned int generation)
 {
 	struct self_id_sequence_enumerator enumerator = {
 		.cursor = sid,
···
 		}
 
 		port_capacity = self_id_sequence_get_port_capacity(quadlet_count);
+		trace_self_id_sequence(self_id_sequence, quadlet_count, generation);
+
 		for (port_index = 0; port_index < port_capacity; ++port_index) {
 			port_status = self_id_sequence_get_port_status(self_id_sequence, quadlet_count,
 								       port_index);
···
 	card->bm_abdicate = bm_abdicate;
 	fw_schedule_bm_work(card, 0);
 
-	local_node = build_tree(card, self_ids, self_id_count);
+	local_node = build_tree(card, self_ids, self_id_count, generation);
 
 	update_topology_map(card, self_ids, self_id_count);
 

drivers/firewire/core-trace.c

···
 // Copyright (c) 2024 Takashi Sakamoto
 
 #include <linux/types.h>
+#include <linux/err.h>
 #include "packet-header-definitions.h"
+#include "phy-packet-definitions.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/firewire.h>
+
+#ifdef TRACEPOINTS_ENABLED
+void copy_port_status(u8 *port_status, unsigned int port_capacity,
+		      const u32 *self_id_sequence, unsigned int quadlet_count)
+{
+	unsigned int port_index;
+
+	for (port_index = 0; port_index < port_capacity; ++port_index) {
+		port_status[port_index] =
+			self_id_sequence_get_port_status(self_id_sequence, quadlet_count, port_index);
+	}
+}
+#endif

include/trace/events/firewire.h

···
 	)
 );
 
+// Some macros are defined in 'drivers/firewire/phy-packet-definitions.h'.
+
+// The content of TP_printk field is preprocessed, then put to the module binary.
+
+#define PHY_PACKET_SELF_ID_GET_PHY_ID(quads)		\
+	((((const u32 *)quads)[0] & SELF_ID_PHY_ID_MASK) >> SELF_ID_PHY_ID_SHIFT)
+
+#define PHY_PACKET_SELF_ID_GET_LINK_ACTIVE(quads)	\
+	((((const u32 *)quads)[0] & SELF_ID_ZERO_LINK_ACTIVE_MASK) >> SELF_ID_ZERO_LINK_ACTIVE_SHIFT)
+
+#define PHY_PACKET_SELF_ID_GET_GAP_COUNT(quads)		\
+	((((const u32 *)quads)[0] & SELF_ID_ZERO_GAP_COUNT_MASK) >> SELF_ID_ZERO_GAP_COUNT_SHIFT)
+
+#define PHY_PACKET_SELF_ID_GET_SCODE(quads)		\
+	((((const u32 *)quads)[0] & SELF_ID_ZERO_SCODE_MASK) >> SELF_ID_ZERO_SCODE_SHIFT)
+
+#define PHY_PACKET_SELF_ID_GET_CONTENDER(quads)		\
+	((((const u32 *)quads)[0] & SELF_ID_ZERO_CONTENDER_MASK) >> SELF_ID_ZERO_CONTENDER_SHIFT)
+
+#define PHY_PACKET_SELF_ID_GET_POWER_CLASS(quads)	\
+	((((const u32 *)quads)[0] & SELF_ID_ZERO_POWER_CLASS_MASK) >> SELF_ID_ZERO_POWER_CLASS_SHIFT)
+
+#define PHY_PACKET_SELF_ID_GET_INITIATED_RESET(quads)	\
+	((((const u32 *)quads)[0] & SELF_ID_ZERO_INITIATED_RESET_MASK) >> SELF_ID_ZERO_INITIATED_RESET_SHIFT)
+
+void copy_port_status(u8 *port_status, unsigned int port_capacity, const u32 *self_id_sequence,
+		      unsigned int quadlet_count);
+
+TRACE_EVENT(self_id_sequence,
+	TP_PROTO(const u32 *self_id_sequence, unsigned int quadlet_count, unsigned int generation),
+	TP_ARGS(self_id_sequence, quadlet_count, generation),
+	TP_STRUCT__entry(
+		__field(u8, generation)
+		__dynamic_array(u8, port_status, self_id_sequence_get_port_capacity(quadlet_count))
+		__dynamic_array(u32, self_id_sequence, quadlet_count)
+	),
+	TP_fast_assign(
+		__entry->generation = generation;
+		copy_port_status(__get_dynamic_array(port_status), __get_dynamic_array_len(port_status),
+				 self_id_sequence, quadlet_count);
+		memcpy(__get_dynamic_array(self_id_sequence), self_id_sequence,
+					   __get_dynamic_array_len(self_id_sequence));
+	),
+	TP_printk(
+		"generation=%u phy_id=0x%02x link_active=%s gap_count=%u scode=%u contender=%s power_class=%u initiated_reset=%s port_status=%s self_id_sequence=%s",
+		__entry->generation,
+		PHY_PACKET_SELF_ID_GET_PHY_ID(__get_dynamic_array(self_id_sequence)),
+		PHY_PACKET_SELF_ID_GET_LINK_ACTIVE(__get_dynamic_array(self_id_sequence)) ? "true" : "false",
+		PHY_PACKET_SELF_ID_GET_GAP_COUNT(__get_dynamic_array(self_id_sequence)),
+		PHY_PACKET_SELF_ID_GET_SCODE(__get_dynamic_array(self_id_sequence)),
+		PHY_PACKET_SELF_ID_GET_CONTENDER(__get_dynamic_array(self_id_sequence)) ? "true" : "false",
+		PHY_PACKET_SELF_ID_GET_POWER_CLASS(__get_dynamic_array(self_id_sequence)),
+		PHY_PACKET_SELF_ID_GET_INITIATED_RESET(__get_dynamic_array(self_id_sequence)) ? "true" : "false",
+		__print_array(__get_dynamic_array(port_status), __get_dynamic_array_len(port_status), 1),
+		__print_array(__get_dynamic_array(self_id_sequence),
+			      __get_dynamic_array_len(self_id_sequence) / QUADLET_SIZE, QUADLET_SIZE)
+	)
+);
+
 #undef QUADLET_SIZE
 
 #endif // _FIREWIRE_TRACE_EVENT_H