[net 0/3][pull request] Intel Wired LAN Driver Updates 2016-04-05

[net 0/3][pull request] Intel Wired LAN Driver Updates 2016-04-05

[Jeff Kirsher]

This series contains updates to i40e and e1000.

Jesse fixes an issue where code was added by a previous commit but the
flag to enable it was never set.

Alex fixes the e1000 driver from grossly overestimated the descriptors
needed to transmit a frame.

The following are changes since commit eb8e97715f29a1240cdf67b0df725be27433259f:
  sctp: use list_* in sctp_list_dequeue
and are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/net-queue master

Alexander Duyck (2):
  e1000: Do not overestimate descriptor counts in Tx pre-check
  e1000: Double Tx descriptors needed check for 82544

Jesse Brandeburg (1):
  i40e: fix errant PCIe bandwidth message

 drivers/net/ethernet/intel/e1000/e1000_main.c | 21 +++++++++++++++++++--
 drivers/net/ethernet/intel/i40e/i40e_main.c   |  1 +
 2 files changed, 20 insertions(+), 2 deletions(-)

-- 
2.5.5

[net 1/3] i40e: fix errant PCIe bandwidth message

[Jeff Kirsher]

From: Jesse Brandeburg <jesse.brandeburg@intel.com>

There was an error introduced with commit 3fced535079a ("i40e: X722 is
on the IOSF bus and does not report the PCI bus info"), where code was
added but the enabling flag is never set.

CC: Anjali Singhai Jain <anjali.singhai@intel.com>
CC: Stefan Assman <sassman@redhat.com>
Fixes: 3fced535079a ("i40e: X722 is on the IOSF bus ...")
Reported-by: Steve Best <sbest@redhat.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 6700643..3449129 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -8559,6 +8559,7 @@ static int i40e_sw_init(struct i40e_pf *pf)
 			     I40E_FLAG_OUTER_UDP_CSUM_CAPABLE |
 			     I40E_FLAG_WB_ON_ITR_CAPABLE |
 			     I40E_FLAG_MULTIPLE_TCP_UDP_RSS_PCTYPE |
+			     I40E_FLAG_NO_PCI_LINK_CHECK |
 			     I40E_FLAG_100M_SGMII_CAPABLE |
 			     I40E_FLAG_USE_SET_LLDP_MIB |
 			     I40E_FLAG_GENEVE_OFFLOAD_CAPABLE;
-- 
2.5.5

[net 2/3] e1000: Do not overestimate descriptor counts in Tx pre-check

[Jeff Kirsher]

From: Alexander Duyck <aduyck@mirantis.com>

The current code path is capable of grossly overestimating the number of
descriptors needed to transmit a new frame.  This specifically occurs if
the skb contains a number of 4K pages.  The issue is that the logic for
determining the descriptors needed is ((S) >> (X)) + 1.  When X is 12 it
means that we were indicating that we required 2 descriptors for each 4K
page when we only needed one.

This change corrects this by instead adding (1 << (X)) - 1 to the S value
instead of adding 1 after the fact.  This way we get an accurate descriptor
needed count as we are essentially doing a DIV_ROUNDUP().

Reported-by: Ivan Suzdal <isuzdal@mirantis.com>
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/e1000/e1000_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 3fc7bde..d213fb4 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -3106,7 +3106,7 @@ static int e1000_maybe_stop_tx(struct net_device *netdev,
 	return __e1000_maybe_stop_tx(netdev, size);
 }
 
-#define TXD_USE_COUNT(S, X) (((S) >> (X)) + 1)
+#define TXD_USE_COUNT(S, X) (((S) + ((1 << (X)) - 1)) >> (X))
 static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
 				    struct net_device *netdev)
 {
-- 
2.5.5

[net 3/3] e1000: Double Tx descriptors needed check for 82544

[Jeff Kirsher]

From: Alexander Duyck <aduyck@mirantis.com>

The 82544 has code that adds one additional descriptor per data buffer.
However we weren't taking that into account when determining the descriptors
needed for the next transmit at the end of the xmit_frame path.

This change takes that into account by doubling the number of descriptors
needed for the 82544 so that we can avoid a potential issue where we could
hang the Tx ring by loading frames with xmit_more enabled and then stopping
the ring without writing the tail.

In addition it adds a few more descriptors to account for some additional
workarounds that have been added over time.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/e1000/e1000_main.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index d213fb4..ae90d4f 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -3256,12 +3256,29 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
 			     nr_frags, mss);
 
 	if (count) {
+		/* The descriptors needed is higher than other Intel drivers
+		 * due to a number of workarounds.  The breakdown is below:
+		 * Data descriptors: MAX_SKB_FRAGS + 1
+		 * Context Descriptor: 1
+		 * Keep head from touching tail: 2
+		 * Workarounds: 3
+		 */
+		int desc_needed = MAX_SKB_FRAGS + 7;
+
 		netdev_sent_queue(netdev, skb->len);
 		skb_tx_timestamp(skb);
 
 		e1000_tx_queue(adapter, tx_ring, tx_flags, count);
+
+		/* 82544 potentially requires twice as many data descriptors
+		 * in order to guarantee buffers don't end on evenly-aligned
+		 * dwords
+		 */
+		if (adapter->pcix_82544)
+			desc_needed += MAX_SKB_FRAGS + 1;
+
 		/* Make sure there is space in the ring for the next send. */
-		e1000_maybe_stop_tx(netdev, tx_ring, MAX_SKB_FRAGS + 2);
+		e1000_maybe_stop_tx(netdev, tx_ring, desc_needed);
 
 		if (!skb->xmit_more ||
 		    netif_xmit_stopped(netdev_get_tx_queue(netdev, 0))) {
-- 
2.5.5

Re: [net 0/3][pull request] Intel Wired LAN Driver Updates 2016-04-05

[David Miller]

From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Date: Tue,  5 Apr 2016 15:30:48 -0700

> This series contains updates to i40e and e1000.

Pulled, thanks Jeff.