Link queues to NAPI instances via netdev-genl API so that users can
query this information with netlink. Handle a few cases in the driver:
1. Link/unlink the NAPIs when XDP is enabled/disabled
2. Handle IGC_FLAG_QUEUE_PAIRS enabled and disabled
Example output when IGC_FLAG_QUEUE_PAIRS is enabled:
$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
{'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
{'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'tx'},
{'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'tx'},
{'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'tx'}]
Since IGC_FLAG_QUEUE_PAIRS is enabled, you'll note that the same NAPI ID
is present for both rx and tx queues at the same index, for example
index 0:
{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'},
To test IGC_FLAG_QUEUE_PAIRS disabled, a test system was booted using
the grub command line option "maxcpus=2" to force
igc_set_interrupt_capability to disable IGC_FLAG_QUEUE_PAIRS.
Example output when IGC_FLAG_QUEUE_PAIRS is disabled:
$ lscpu | grep "On-line CPU"
On-line CPU(s) list: 0,2
$ ethtool -l enp86s0 | tail -5
Current hardware settings:
RX: n/a
TX: n/a
Other: 1
Combined: 2
$ cat /proc/interrupts | grep enp
144: [...] enp86s0
145: [...] enp86s0-rx-0
146: [...] enp86s0-rx-1
147: [...] enp86s0-tx-0
148: [...] enp86s0-tx-1
1 "other" IRQ, and 2 IRQs for each of RX and Tx, so we expect netlink to
report 4 IRQs with unique NAPI IDs:
$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
--dump napi-get --json='{"ifindex": 2}'
[{'id': 8196, 'ifindex': 2, 'irq': 148},
{'id': 8195, 'ifindex': 2, 'irq': 147},
{'id': 8194, 'ifindex': 2, 'irq': 146},
{'id': 8193, 'ifindex': 2, 'irq': 145}]
Now we examine which queues these NAPIs are associated with, expecting
that since IGC_FLAG_QUEUE_PAIRS is disabled each RX and TX queue will
have its own NAPI instance:
$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'napi-id': 8195, 'type': 'tx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8196, 'type': 'tx'}]
Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
Reviewed-by: Vitaly Lifshits <vitaly.lifshits@xxxxxxxxx>
---
v6:
- Rename __igc_do_resume to __igc_resume and rename the boolean
argument "need_rtnl" to "rpm" as seen in igb, as per Vitaly's
feedback to make the code look more like commit ac8c58f5b535 ("igb:
fix deadlock caused by taking RTNL in RPM resume path").
v5:
- Rename igc_resume to __igc_do_resume and pass in a boolean
"need_rtnl" to signal whether or not rtnl should be held before
caling __igc_open. Call this new function from igc_runtime_resume
and igc_resume passing in false (for igc_runtime_resume) and true
(igc_resume), respectively. This is done to avoid reintroducing a
bug fixed in commit: 6f31d6b: "igc: Refactor runtime power
management flow" where rtnl is held in runtime_resume causing a
deadlock.
v4:
- Add rtnl_lock/rtnl_unlock in two paths: igc_resume and
igc_io_error_detected. The code added to the latter is inspired by
a similar implementation in ixgbe's ixgbe_io_error_detected.
v3:
- Replace igc_unset_queue_napi with igc_set_queue_napi(adapater, i,
NULL), as suggested by Vinicius Costa Gomes
- Simplify implemention of igc_set_queue_napi as suggested by Kurt
Kanzenbach, with a tweak to use ring->queue_index
v2:
- Update commit message to include tests for IGC_FLAG_QUEUE_PAIRS
disabled
- Refactored code to move napi queue mapping and unmapping to helper
functions igc_set_queue_napi and igc_unset_queue_napi
- Adjust the code to handle IGC_FLAG_QUEUE_PAIRS disabled
- Call helpers to map/unmap queues to NAPIs in igc_up, __igc_open,
igc_xdp_enable_pool, and igc_xdp_disable_pool
drivers/net/ethernet/intel/igc/igc.h | 2 +
drivers/net/ethernet/intel/igc/igc_main.c | 56 +++++++++++++++++++----
drivers/net/ethernet/intel/igc/igc_xdp.c | 2 +
3 files changed, 51 insertions(+), 9 deletions(-)
