iwlwifi: pcie: implement GRO without NAPI

Use the new NAPI infrastructure added to mac80211 to get
GRO. We don't really implement NAPI since we don't have
a real poll function and we never schedule a NAPI poll.
Instead of this, we collect all the packets we got from a
single interrupt and then call napi_gro_flush().

This allows us to benefit from GRO. In half duplex medium
like WiFi, its main advantage is that it reduces the number
of TCP Acks, hence improving the TCP Rx performance.

Since we call the Rx path with a spinlock held, remove
the might_sleep mention from the op_mode's API.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Ido Yariv <ido@wizery.com>
[Squash different patches and rewrite the commit message]
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 22 insertions, 3 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-op-mode.h b/drivers/net/wireless/iwlwifi/iwl-op-mode.h
index ea29504ac617..99785c892f96 100644
--- a/drivers/net/wireless/iwlwifi/iwl-op-mode.h
+++ b/drivers/net/wireless/iwlwifi/iwl-op-mode.h
@@ -63,6 +63,7 @@
 #ifndef __iwl_op_mode_h__
 #define __iwl_op_mode_h__
 
+#include <linux/netdevice.h>
 #include <linux/debugfs.h>
 
 struct iwl_op_mode;
@@ -112,8 +113,11 @@ struct iwl_cfg;
  * @stop: stop the op_mode. Must free all the memory allocated.
  *	May sleep
  * @rx: Rx notification to the op_mode. rxb is the Rx buffer itself. Cmd is the
- *	HCMD this Rx responds to.
- *	This callback may sleep, it is called from a threaded IRQ handler.
+ *	HCMD this Rx responds to. Can't sleep.
+ * @napi_add: NAPI initialisation. The transport is fully responsible for NAPI,
+ *	but the higher layers need to know about it (in particular mac80211 to
+ *	to able to call the right NAPI RX functions); this function is needed
+ *	to eventually call netif_napi_add() with higher layer involvement.
  * @queue_full: notifies that a HW queue is full.
  *	Must be atomic and called with BH disabled.
  * @queue_not_full: notifies that a HW queue is not full any more.
@@ -143,6 +147,11 @@ struct iwl_op_mode_ops {
 	void (*stop)(struct iwl_op_mode *op_mode);
 	int (*rx)(struct iwl_op_mode *op_mode, struct iwl_rx_cmd_buffer *rxb,
 		  struct iwl_device_cmd *cmd);
+	void (*napi_add)(struct iwl_op_mode *op_mode,
+			 struct napi_struct *napi,
+			 struct net_device *napi_dev,
+			 int (*poll)(struct napi_struct *, int),
+			 int weight);
 	void (*queue_full)(struct iwl_op_mode *op_mode, int queue);
 	void (*queue_not_full)(struct iwl_op_mode *op_mode, int queue);
 	bool (*hw_rf_kill)(struct iwl_op_mode *op_mode, bool state);
@@ -180,7 +189,6 @@ static inline int iwl_op_mode_rx(struct iwl_op_mode *op_mode,
 				  struct iwl_rx_cmd_buffer *rxb,
 				  struct iwl_device_cmd *cmd)
 {
-	might_sleep();
 	return op_mode->ops->rx(op_mode, rxb, cmd);
 }
 
@@ -249,4 +257,15 @@ static inline int iwl_op_mode_exit_d0i3(struct iwl_op_mode *op_mode)
 	return op_mode->ops->exit_d0i3(op_mode);
 }
 
+static inline void iwl_op_mode_napi_add(struct iwl_op_mode *op_mode,
+					struct napi_struct *napi,
+					struct net_device *napi_dev,
+					int (*poll)(struct napi_struct *, int),
+					int weight)
+{
+	if (!op_mode->ops->napi_add)
+		return;
+	op_mode->ops->napi_add(op_mode, napi, napi_dev, poll, weight);
+}
+
 #endif /* __iwl_op_mode_h__ */