We use spinlock to access a single flag. We can avoid spin_locks by using
atomic variable and atomic_cmpxchg(). Use atomic_cmpxchg to set the flag
for idle to poll. And a simple atomic_set to unlock (set idle from poll).
In napi poll, if gro is enabled, we call napi_gro_receive() to deliver the
packets. Before we call napi_complete(), i.e while re-polling, if low
latency busy poll is called, we use netif_receive_skb() to deliver the packets.
At this point if there are some skb's held in GRO, busy poll could deliver the
packets out of order. So we call napi_gro_flush() to flush skbs before we
move the napi poll to idle.
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for low latency busy_poll.
* Introduce drivers ndo_busy_poll function enic_busy_poll, which is called by
socket waiting for data.
* Introduce locking between napi_poll nad busy_poll
* enic_busy_poll cleans up all the rx pkts possible. While in busy_poll, rq
holds the state ENIC_POLL_STATE_POLL. While in napi_poll, rq holds the state
ENIC_POLL_STATE_NAPI.
* in napi_poll we return if we are in busy_poll. Incase of INTx & msix, we just
service wq and return if busy_poll is going on.
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch,
- Adds new firmware commands for the new Cisco Low Latency NIC
(aka. USNIC).
Signed-off-by: Neel Patel <neepatel@cisco.com>
Signed-off-by: Nishank Trivedi <nistrive@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the Cisco driver into drivers/net/ethernet/cisco/ and make the
necessary Kconfig and Makefile changes.
CC: Christian Benvenuti <benve@cisco.com>
CC: Vasanthy Kolluri <vkolluri@cisco.com>
CC: Roopa Prabhu <roprabhu@cisco.com>
CC: David Wang <dwang2@cisco.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>