firewire: cdev: implement new event to notify response subaction with time stamp

The callback function now receives an argument for time stamps relevant
to asynchronous transaction. This commit implements a new event to
notify response subaction with the time stamps for user space.

Link: https://lore.kernel.org/r/20230529113406.986289-10-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 315ebc8c545d13e4ec70440a4b767ba668401701..8b24abdd51b8e3f318ffc8da1e746c705fe166b9 100644 (file)
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -172,6 +172,7 @@ struct outbound_transaction_event {
        struct outbound_transaction_resource r;
        union {
                struct fw_cdev_event_response without_tstamp;
+               struct fw_cdev_event_response2 with_tstamp;
        } rsp;
 };
 
@@ -538,41 +539,64 @@ static void release_transaction(struct client *client,
 {
 }
 
-static void complete_transaction(struct fw_card *card, int rcode,
-                                void *payload, size_t length, void *data)
+static void complete_transaction(struct fw_card *card, int rcode, u32 request_tstamp,
+                                u32 response_tstamp, void *payload, size_t length, void *data)
 {
        struct outbound_transaction_event *e = data;
-       struct fw_cdev_event_response *rsp = &e->rsp.without_tstamp;
        struct client *client = e->client;
        unsigned long flags;
 
-       if (length < rsp->length)
-               rsp->length = length;
-       if (rcode == RCODE_COMPLETE)
-               memcpy(rsp->data, payload, rsp->length);
-
        spin_lock_irqsave(&client->lock, flags);
        idr_remove(&client->resource_idr, e->r.resource.handle);
        if (client->in_shutdown)
                wake_up(&client->tx_flush_wait);
        spin_unlock_irqrestore(&client->lock, flags);
 
-       rsp->type = FW_CDEV_EVENT_RESPONSE;
-       rsp->rcode = rcode;
+       switch (e->rsp.without_tstamp.type) {
+       case FW_CDEV_EVENT_RESPONSE:
+       {
+               struct fw_cdev_event_response *rsp = &e->rsp.without_tstamp;
+
+               if (length < rsp->length)
+                       rsp->length = length;
+               if (rcode == RCODE_COMPLETE)
+                       memcpy(rsp->data, payload, rsp->length);
+
+               rsp->rcode = rcode;
+
+               // In the case that sizeof(*rsp) doesn't align with the position of the
+               // data, and the read is short, preserve an extra copy of the data
+               // to stay compatible with a pre-2.6.27 bug.  Since the bug is harmless
+               // for short reads and some apps depended on it, this is both safe
+               // and prudent for compatibility.
+               if (rsp->length <= sizeof(*rsp) - offsetof(typeof(*rsp), data))
+                       queue_event(client, &e->event, rsp, sizeof(*rsp), rsp->data, rsp->length);
+               else
+                       queue_event(client, &e->event, rsp, sizeof(*rsp) + rsp->length, NULL, 0);
 
-       /*
-        * In the case that sizeof(*rsp) doesn't align with the position of the
-        * data, and the read is short, preserve an extra copy of the data
-        * to stay compatible with a pre-2.6.27 bug.  Since the bug is harmless
-        * for short reads and some apps depended on it, this is both safe
-        * and prudent for compatibility.
-        */
-       if (rsp->length <= sizeof(*rsp) - offsetof(typeof(*rsp), data))
-               queue_event(client, &e->event, rsp, sizeof(*rsp),
-                           rsp->data, rsp->length);
-       else
-               queue_event(client, &e->event, rsp, sizeof(*rsp) + rsp->length,
-                           NULL, 0);
+               break;
+       }
+       case FW_CDEV_EVENT_RESPONSE2:
+       {
+               struct fw_cdev_event_response2 *rsp = &e->rsp.with_tstamp;
+
+               if (length < rsp->length)
+                       rsp->length = length;
+               if (rcode == RCODE_COMPLETE)
+                       memcpy(rsp->data, payload, rsp->length);
+
+               rsp->rcode = rcode;
+               rsp->request_tstamp = request_tstamp;
+               rsp->response_tstamp = response_tstamp;
+
+               queue_event(client, &e->event, rsp, sizeof(*rsp) + rsp->length, NULL, 0);
+
+               break;
+       default:
+               WARN_ON(1);
+               break;
+       }
+       }
 
        /* Drop the idr's reference */
        client_put(client);
@@ -583,7 +607,6 @@ static int init_request(struct client *client,
                        int destination_id, int speed)
 {
        struct outbound_transaction_event *e;
-       struct fw_cdev_event_response *rsp;
        void *payload;
        int ret;
 
@@ -600,10 +623,21 @@ static int init_request(struct client *client,
                return -ENOMEM;
        e->client = client;
 
-       rsp = &e->rsp.without_tstamp;
-       rsp->length = request->length;
-       rsp->closure = request->closure;
-       payload = rsp->data;
+       if (client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
+               struct fw_cdev_event_response *rsp = &e->rsp.without_tstamp;
+
+               rsp->type = FW_CDEV_EVENT_RESPONSE;
+               rsp->length = request->length;
+               rsp->closure = request->closure;
+               payload = rsp->data;
+       } else {
+               struct fw_cdev_event_response2 *rsp = &e->rsp.with_tstamp;
+
+               rsp->type = FW_CDEV_EVENT_RESPONSE2;
+               rsp->length = request->length;
+               rsp->closure = request->closure;
+               payload = rsp->data;
+       }
 
        if (request->data && copy_from_user(payload, u64_to_uptr(request->data), request->length)) {
                ret = -EFAULT;
@@ -615,9 +649,9 @@ static int init_request(struct client *client,
        if (ret < 0)
                goto failed;
 
-       fw_send_request(client->device->card, &e->r.transaction, request->tcode, destination_id,
-                       request->generation, speed, request->offset, payload, request->length,
-                       complete_transaction, e);
+       fw_send_request_with_tstamp(client->device->card, &e->r.transaction, request->tcode,
+                                   destination_id, request->generation, speed, request->offset,
+                                   payload, request->length, complete_transaction, e);
        return 0;
 
  failed: