linux-stable.git/drivers/net/ntb_netdev.c, branch linux-4.9.y

ntb_netdev: Use dev_kfree_skb_any() in interrupt context

2023-01-07T11:07:22+00:00

[ Upstream commit 5f7d78b2b12a9d561f48fa00bab29b40f4616dad ]

TX/RX callback handlers (ntb_netdev_tx_handler(),
ntb_netdev_rx_handler()) can be called in interrupt
context via the DMA framework when the respective
DMA operations have completed. As such, any calls
by these routines to free skb's, should use the
interrupt context safe dev_kfree_skb_any() function.

Previously, these callback handlers would call the
interrupt unsafe version of dev_kfree_skb(). This has
not presented an issue on Intel IOAT DMA engines as
that driver utilizes tasklets rather than a hard
interrupt handler, like the AMD PTDMA DMA driver.
On AMD systems, a kernel WARNING message is
encountered, which is being issued from
skb_release_head_state() due to in_hardirq()
being true.

Besides the user visible WARNING from the kernel,
the other symptom of this bug was that TCP/IP performance
across the ntb_netdev interface was very poor, i.e.
approximately an order of magnitude below what was
expected. With the repair to use dev_kfree_skb_any(),
kernel WARNINGs from skb_release_head_state() ceased
and TCP/IP performance, as measured by iperf, was on
par with expected results, approximately 20 Gb/s on
AMD Milan based server. Note that this performance
is comparable with Intel based servers.

Fixes: 765ccc7bc3d91 ("ntb_netdev: correct skb leak")
Fixes: 548c237c0a997 ("net: Add support for NTB virtual ethernet device")
Signed-off-by: Eric Pilmore 
Reviewed-by: Dave Jiang 
Link: https://lore.kernel.org/r/20221209000659.8318-1-epilmore@gigaio.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: net_netdev: Fix error handling in ntb_netdev_init_module()

2022-12-08T10:15:41+00:00

[ Upstream commit b8f79dccd38edf7db4911c353d9cd792ab13a327 ]

The ntb_netdev_init_module() returns the ntb_transport_register_client()
directly without checking its return value, if
ntb_transport_register_client() failed, the NTB client device is not
unregistered.

Fix by unregister NTB client device when ntb_transport_register_client()
failed.

Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device")
Signed-off-by: Yuan Can 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ntb_netdev: fix sleep time mismatch

2019-11-28T17:28:52+00:00

[ Upstream commit a861594b1b7ffd630f335b351c4e9f938feadb8e ]

The tx_time should be in usecs (according to the comment above the
variable), but the setting of the timer during the rearming is done in
msecs.  Change it to match the expected units.

Fixes: e74bfeedad08 ("NTB: Add flow control to the ntb_netdev")
Suggested-by: Gerd W. Haeussler 
Signed-off-by: Jon Mason 
Acked-by: Dave Jiang 
Signed-off-by: Sasha Levin

NTB: Add flow control to the ntb_netdev

2015-09-07T19:17:08+00:00

Right now if we push the NTB really hard, we start dropping packets due
to not able to process the packets fast enough. We need to st:qop the
upper layer from flooding us when that happens.

A timer is necessary in order to restart the queue once the resource has
been processed on the receive side. Due to the way NTB is setup, the
resources on the tx side are tied to the processing of the rx side and
there's no async way to know when the rx side has released those
resources.

Signed-off-by: Dave Jiang 
Signed-off-by: Jon Mason

NTB: ntb_netdev not covering all receive errors

2015-08-09T20:32:21+00:00

ntb_netdev is allowing the link to come up even when -ENOMEM is returned
from ntb_transport_rx_enqueue.  Fix to cover all possible errors.

Signed-off-by: Dave Jiang 
Signed-off-by: Jon Mason

NTB: Fix ntb_transport out-of-order RX update

2015-08-09T20:32:21+00:00

It was possible for a synchronous update of the RX index in the error
case to get ahead of the asynchronous RX index update in the normal
case.  Change the RX processing to preserve an RX completion order.

There were two error cases.  First, if a buffer is not present to
receive data, there would be no queue entry to preserve the RX
completion order.  Instead of dropping the RX frame, leave the RX frame
in the ring.  Schedule RX processing when RX entries are enqueued, in
case there are RX frames waiting in the ring to be received.

Second, if a buffer is too small to receive data, drop the frame in the
ring, mark the RX entry as done, and indicate the error in the RX entry
length.  Check for a negative length in the receive callback in
ntb_netdev, and count occurrences as rx_length_errors.

Signed-off-by: Allen Hubbe 
Signed-off-by: Jon Mason

NTB: Split ntb_hw_intel and ntb_transport drivers

2015-07-04T18:05:49+00:00

Change ntb_hw_intel to use the new NTB hardware abstraction layer.

Split ntb_transport into its own driver.  Change it to use the new NTB
hardware abstraction layer.

Signed-off-by: Allen Hubbe 
Signed-off-by: Jon Mason

NTB: Move files in preparation for NTB abstraction

2015-07-02T14:09:23+00:00

This patch only moves files to their new locations, before applying the
next two patches adding the NTB Abstraction layer.  Splitting this patch
from the next is intended make distinct which code is changed only due
to moving the files, versus which are substantial code changes in adding
the NTB Abstraction layer.

Signed-off-by: Allen Hubbe 
Signed-off-by: Jon Mason

net: use ethtool_cmd_speed_set helper to set ethtool speed value

2014-06-06T23:24:07+00:00

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: get rid of SET_ETHTOOL_OPS

2014-05-13T21:43:20+00:00

net: get rid of SET_ETHTOOL_OPS

Dave Miller mentioned he'd like to see SET_ETHTOOL_OPS gone.
This does that.

Mostly done via coccinelle script:
@@
struct ethtool_ops *ops;
struct net_device *dev;
@@
-       SET_ETHTOOL_OPS(dev, ops);
+       dev->ethtool_ops = ops;

Compile tested only, but I'd seriously wonder if this broke anything.

Suggested-by: Dave Miller 
Signed-off-by: Wilfried Klaebe 
Acked-by: Felipe Balbi 
Signed-off-by: David S. Miller