firewire: cdev: implement new event relevant to phy packet with time stamp

In 1394 OHCI, the OUTPUT_LAST descriptor of Asynchronous Transmit (AT)
context has timeStamp field, in which 1394 OHCI controller record the
isochronous cycle when the packet was sent for the request subaction.
Additionally, the trailing quadlet of Asynchronous Receive (AR) context
has timeStamp field as well in which 1394 OHCI controller record the
isochronous cycle when the packet arrived. The time stamps are also
available for the cases to send and receive phy packet.

This commit implements new events with time stamp field for user space.

Link: https://lore.kernel.org/r/20230529113406.986289-13-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

Author: takaswie

drivers/firewire/core-cdev.c

@@ -206,13 +206,15 @@ struct outbound_phy_packet_event {
 	struct fw_packet p;
 	union {
 		struct fw_cdev_event_phy_packet without_tstamp;
+		struct fw_cdev_event_phy_packet2 with_tstamp;
 	} phy_packet;
 };
 
 struct inbound_phy_packet_event {
 	struct event event;
 	union {
 		struct fw_cdev_event_phy_packet without_tstamp;
+		struct fw_cdev_event_phy_packet2 with_tstamp;
 	} phy_packet;
 };
 
@@ -1555,7 +1557,6 @@ static void outbound_phy_packet_callback(struct fw_packet *packet,
 		container_of(packet, struct outbound_phy_packet_event, p);
 	struct client *e_client = e->client;
 	u32 rcode;
-	struct fw_cdev_event_phy_packet *pp;
 
 	switch (status) {
 	// expected:
@@ -1583,10 +1584,31 @@ static void outbound_phy_packet_callback(struct fw_packet *packet,
 		break;
 	}
 
-	pp = &e->phy_packet.without_tstamp;
-	pp->rcode = rcode;
-	pp->data[0] = packet->timestamp;
-	queue_event(e->client, &e->event, &e->phy_packet, sizeof(*pp) + pp->length, NULL, 0);
+	switch (e->phy_packet.without_tstamp.type) {
+	case FW_CDEV_EVENT_PHY_PACKET_SENT:
+	{
+		struct fw_cdev_event_phy_packet *pp = &e->phy_packet.without_tstamp;
+
+		pp->rcode = rcode;
+		pp->data[0] = packet->timestamp;
+		queue_event(e->client, &e->event, &e->phy_packet, sizeof(*pp) + pp->length,
+			    NULL, 0);
+		break;
+	}
+	case FW_CDEV_EVENT_PHY_PACKET_SENT2:
+	{
+		struct fw_cdev_event_phy_packet2 *pp = &e->phy_packet.with_tstamp;
+
+		pp->rcode = rcode;
+		pp->tstamp = packet->timestamp;
+		queue_event(e->client, &e->event, &e->phy_packet, sizeof(*pp) + pp->length,
+			    NULL, 0);
+		break;
+	}
+	default:
+		WARN_ON(1);
+		break;
+	}
 
 	client_put(e_client);
 }
@@ -1596,13 +1618,12 @@ static int ioctl_send_phy_packet(struct client *client, union ioctl_arg *arg)
 	struct fw_cdev_send_phy_packet *a = &arg->send_phy_packet;
 	struct fw_card *card = client->device->card;
 	struct outbound_phy_packet_event *e;
-	struct fw_cdev_event_phy_packet *pp;
 
 	/* Access policy: Allow this ioctl only on local nodes' device files. */
 	if (!client->device->is_local)
 		return -ENOSYS;
 
-	e = kzalloc(sizeof(*e) + 4, GFP_KERNEL);
+	e = kzalloc(sizeof(*e) + sizeof(a->data), GFP_KERNEL);
 	if (e == NULL)
 		return -ENOMEM;
 
@@ -1616,11 +1637,23 @@ static int ioctl_send_phy_packet(struct client *client, union ioctl_arg *arg)
 	e->p.header_length	= 12;
 	e->p.callback		= outbound_phy_packet_callback;
 
-	pp = &e->phy_packet.without_tstamp;
-	pp->closure = a->closure;
-	pp->type = FW_CDEV_EVENT_PHY_PACKET_SENT;
-	if (is_ping_packet(a->data))
-		pp->length = 4;
+	if (client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
+		struct fw_cdev_event_phy_packet *pp = &e->phy_packet.without_tstamp;
+
+		pp->closure = a->closure;
+		pp->type = FW_CDEV_EVENT_PHY_PACKET_SENT;
+		if (is_ping_packet(a->data))
+			pp->length = 4;
+	} else {
+		struct fw_cdev_event_phy_packet2 *pp = &e->phy_packet.with_tstamp;
+
+		pp->closure = a->closure;
+		pp->type = FW_CDEV_EVENT_PHY_PACKET_SENT2;
+		// Keep the data field so that application can match the response event to the
+		// request.
+		pp->length = sizeof(a->data);
+		memcpy(pp->data, a->data, sizeof(a->data));
+	}
 
 	card->driver->send_request(card, &e->p);
 
@@ -1655,20 +1688,33 @@ void fw_cdev_handle_phy_packet(struct fw_card *card, struct fw_packet *p)
 	spin_lock_irqsave(&card->lock, flags);
 
 	list_for_each_entry(client, &card->phy_receiver_list, phy_receiver_link) {
-		struct fw_cdev_event_phy_packet *pp;
-
 		e = kmalloc(sizeof(*e) + 8, GFP_ATOMIC);
 		if (e == NULL)
 			break;
 
-		pp = &e->phy_packet.without_tstamp;
-		pp->closure = client->phy_receiver_closure;
-		pp->type = FW_CDEV_EVENT_PHY_PACKET_RECEIVED;
-		pp->rcode = RCODE_COMPLETE;
-		pp->length = 8;
-		pp->data[0] = p->header[1];
-		pp->data[1] = p->header[2];
-		queue_event(client, &e->event, &e->phy_packet, sizeof(*pp) + 8, NULL, 0);
+		if (client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
+			struct fw_cdev_event_phy_packet *pp = &e->phy_packet.without_tstamp;
+
+			pp->closure = client->phy_receiver_closure;
+			pp->type = FW_CDEV_EVENT_PHY_PACKET_RECEIVED;
+			pp->rcode = RCODE_COMPLETE;
+			pp->length = 8;
+			pp->data[0] = p->header[1];
+			pp->data[1] = p->header[2];
+			queue_event(client, &e->event, &e->phy_packet, sizeof(*pp) + 8, NULL, 0);
+		} else {
+			struct fw_cdev_event_phy_packet2 *pp = &e->phy_packet.with_tstamp;
+
+			pp = &e->phy_packet.with_tstamp;
+			pp->closure = client->phy_receiver_closure;
+			pp->type = FW_CDEV_EVENT_PHY_PACKET_RECEIVED2;
+			pp->rcode = RCODE_COMPLETE;
+			pp->length = 8;
+			pp->tstamp = p->timestamp;
+			pp->data[0] = p->header[1];
+			pp->data[1] = p->header[2];
+			queue_event(client, &e->event, &e->phy_packet, sizeof(*pp) + 8, NULL, 0);
+		}
 	}
 
 	spin_unlock_irqrestore(&card->lock, flags);