[PATCH v2 net 0/6] eth: bnxt: fix several bugs in the bnxt module

[Taehee Yoo <ap420073@gmail.com>]

The first fixes setting incorrect skb->truesize.
When xdp-mb prog returns XDP_PASS, skb is allocated and initialized.
Currently, The truesize is calculated as BNXT_RX_PAGE_SIZE *
sinfo->nr_frags, but sinfo->nr_frags is flushed by napi_build_skb().
So, it stores sinfo before calling napi_build_skb() and then use it
for calculate truesize.

The second fixes kernel panic in the bnxt_queue_mem_alloc().
The bnxt_queue_mem_alloc() accesses rx ring descriptor.
rx ring descriptors are allocated when the interface is up and it's
freed when the interface is down.
So, if bnxt_queue_mem_alloc() is called when the interface is down,
kernel panic occurs.
This patch makes the bnxt_queue_mem_alloc() return -ENETDOWN if rx ring
descriptors are not allocated.

The third patch fixes kernel panic in the bnxt_queue_{start | stop}().
When a queue is restarted bnxt_queue_{start | stop}() are called.
These functions set MRU to 0 to stop packet flow and then to set up the
remaining things.
MRU variable is a member of vnic_info[] the first vnic_info is for
default and the second is for ntuple.
The first vnic_info is always allocated when interface is up, but the
second is allocated only when ntuple is enabled.
(ethtool -K eth0 ntuple <on | off>).
Currently, the bnxt_queue_{start | stop}() access
vnic_info[BNXT_VNIC_NTUPLE] regardless of whether ntuple is enabled or
not.
So kernel panic occurs.
This patch make the bnxt_queue_{start | stop}() use bp->nr_vnics instead
of BNXT_VNIC_NTUPLE.

The fourth patch fixes a warning due to checksum state.
The bnxt_rx_pkt() checks whether skb->ip_summed is not CHECKSUM_NONE
before updating ip_summed. if ip_summed is not CHECKSUM_NONE, it WARNS
about it. However, the bnxt_xdp_build_skb() is called in XDP-MB-PASS
path and it updates ip_summed earlier than bnxt_rx_pkt().
So, in the XDP-MB-PASS path, the bnxt_rx_pkt() always warns about
checksum.
Updating ip_summed at the bnxt_xdp_build_skb() is unnecessary and
duplicate, so it is removed.

The fifth patch makes net_devmem_unbind_dmabuf() ignore -ENETDOWN.
When devmem socket is closed, net_devmem_unbind_dmabuf() is called to
unbind/release resources.
If interface is down, the driver returns -ENETDOWN.
The -ENETDOWN return value is not an actual error, because the interface
will release resources when the interface is down.
So, net_devmem_unbind_dmabuf() needs to ignore -ENETDOWN.

The last patch adds XDP testcases to
tools/testing/selftests/drivers/net/ping.py.

v2:
 - Do not use num_frags in the bnxt_xdp_build_skb(). (1/6)
 - Add Review tags from Somnath and Jakub. (2/6)
 - Add new patch for fixing checksum warning. (4/6)
 - Add new patch for fixing warning in net_devmem_unbind_dmabuf(). (5/6)
 - Add new XDP testcases to ping.py (6/6)

Taehee Yoo (6):
  eth: bnxt: fix truesize for mb-xdp-pass case
  eth: bnxt: return fail if interface is down in bnxt_queue_mem_alloc()
  eth: bnxt: do not use BNXT_VNIC_NTUPLE unconditionally in queue
    restart logic
  eth: bnxt: do not update checksum in bnxt_xdp_build_skb()
  net: devmem: do not WARN conditionally after netdev_rx_queue_restart()
  selftests: drv-net: add xdp cases for ping.py

 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |  36 ++--
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c |  18 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h |   6 +-
 net/core/devmem.c                             |   4 +-
 tools/testing/selftests/drivers/net/ping.py   | 200 ++++++++++++++++--
 .../testing/selftests/net/lib/xdp_dummy.bpf.c |   6 +
 6 files changed, 221 insertions(+), 49 deletions(-)

-- 
2.34.1