sfc: Add channel specific receive_skb handler and post_remove callback

Allows an extra channel to override the standard receive_skb handler
and also for extra non generic operations to be performed on remove.

Also set default rx strategy so only skbs can be delivered to the
PTP receive function.

Signed-off-by: Stuart Hodgson <smhodgson@solarflare.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

drivers/net/ethernet/sfc/efx.c

@@ -734,6 +734,7 @@ static void efx_remove_channel(struct efx_channel *channel)
 	efx_for_each_possible_channel_tx_queue(tx_queue, channel)
 		efx_remove_tx_queue(tx_queue);
 	efx_remove_eventq(channel);
+	channel->type->post_remove(channel);
 }
 
 static void efx_remove_channels(struct efx_nic *efx)
@@ -852,6 +853,7 @@ void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
 
 static const struct efx_channel_type efx_default_channel_type = {
 	.pre_probe		= efx_channel_dummy_op_int,
+	.post_remove		= efx_channel_dummy_op_void,
 	.get_name		= efx_get_channel_name,
 	.copy			= efx_copy_channel,
 	.keep_eventq		= false,
@@ -862,6 +864,10 @@ int efx_channel_dummy_op_int(struct efx_channel *channel)
 	return 0;
 }
 
+void efx_channel_dummy_op_void(struct efx_channel *channel)
+{
+}
+
 /**************************************************************************
  *
  * Port handling

drivers/net/ethernet/sfc/efx.h

@@ -102,6 +102,7 @@ static inline void efx_filter_rfs_expire(struct efx_channel *channel) {}
 
 /* Channels */
 extern int efx_channel_dummy_op_int(struct efx_channel *channel);
+extern void efx_channel_dummy_op_void(struct efx_channel *channel);
 extern void efx_process_channel_now(struct efx_channel *channel);
 extern int
 efx_realloc_channels(struct efx_nic *efx, u32 rxq_entries, u32 txq_entries);

drivers/net/ethernet/sfc/net_driver.h

@@ -393,14 +393,17 @@ struct efx_channel {
  * @get_name: Generate the channel's name (used for its IRQ handler)
  * @copy: Copy the channel state prior to reallocation.  May be %NULL if
  *	reallocation is not supported.
+ * @receive_skb: Handle an skb ready to be passed to netif_receive_skb()
  * @keep_eventq: Flag for whether event queue should be kept initialised
  *	while the device is stopped
  */
 struct efx_channel_type {
 	void (*handle_no_channel)(struct efx_nic *);
 	int (*pre_probe)(struct efx_channel *);
+	void (*post_remove)(struct efx_channel *);
 	void (*get_name)(struct efx_channel *, char *buf, size_t len);
 	struct efx_channel *(*copy)(const struct efx_channel *);
+	void (*receive_skb)(struct efx_channel *, struct sk_buff *);
 	bool keep_eventq;
 };
 

drivers/net/ethernet/sfc/rx.c

@@ -575,7 +575,10 @@ static void efx_rx_deliver(struct efx_channel *channel,
 	skb_record_rx_queue(skb, channel->rx_queue.core_index);
 
 	/* Pass the packet up */
-	netif_receive_skb(skb);
+	if (channel->type->receive_skb)
+		channel->type->receive_skb(channel, skb);
+	else
+		netif_receive_skb(skb);
 
 	/* Update allocation strategy method */
 	channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
@@ -617,7 +620,8 @@ void __efx_rx_packet(struct efx_channel *channel, struct efx_rx_buffer *rx_buf)
 	if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
 		rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
 
-	if (likely(rx_buf->flags & (EFX_RX_BUF_PAGE | EFX_RX_PKT_CSUMMED)))
+	if (likely(rx_buf->flags & (EFX_RX_BUF_PAGE | EFX_RX_PKT_CSUMMED)) &&
+	    !channel->type->receive_skb)
 		efx_rx_packet_gro(channel, rx_buf, eh);
 	else
 		efx_rx_deliver(channel, rx_buf);
@@ -627,6 +631,11 @@ void efx_rx_strategy(struct efx_channel *channel)
 {
 	enum efx_rx_alloc_method method = rx_alloc_method;
 
+	if (channel->type->receive_skb) {
+		channel->rx_alloc_push_pages = false;
+		return;
+	}
+
 	/* Only makes sense to use page based allocation if GRO is enabled */
 	if (!(channel->efx->net_dev->features & NETIF_F_GRO)) {
 		method = RX_ALLOC_METHOD_SKB;