[PATCH net-next 0/9] ionic: Add support for Event Queues

[Shannon Nelson <snelson@pensando.io>]

In configurations where we have many CPU cores and want lots
of queues in each device, we can easily run out of interrupt
resources, and so need to find ways to limit our usage, either
by using fewer queues, or by multiplexing the interrupt needs.

This patchset adds a new EventQueue feature that can be used
for multiplexing the interrupts if we find that we can't get
enough from the system to support our configuration.  We can
create a small number of EQs that use interrupts, and have
the TxRx queue pairs subscribe to event messages that come
through the EQs, selecting an EQ with (TxIndex % numEqs).

The interrupt messages normally generated by packet events
become events in the EQ, and the EQ handler will schedule napi
sessions for the queues subscribed to the particular event.

The use of EQs is driven by the firmware configuration - if
it shows support for ethernet event queues (eq_count in the
device identity), the driver will try to use them instead of
regular interrupts per TxRx queuepair.  If for some reason
the EQ setup fails, the driver falls back to using regular
TxRx interrupts.

The first 3 patches are prep work, the next 4 build up the
Event Queue support, the 8th links in and uses the new EQs,
and the final patch adds a bit of debugging assistance if
things ever go very wrong in probe.

Signed-off-by: Shannon Nelson <snelson@pensando.io>

Shannon Nelson (9):
  ionic: change param from lif to ionic
  ionic: rename rdma eqs field
  ionic: replace lif list with xarray
  ionic: add event queue definitions to hw interface
  ionic: rename napi irq functions
  ionic: add functions for setup and tear down event queues
  ionic: add q ident query for eq
  ionic: add basic eq support
  ionic: keep ionic dev on lif init fail

 drivers/net/ethernet/pensando/ionic/ionic.h   |  20 +-
 .../ethernet/pensando/ionic/ionic_bus_pci.c   |   8 +
 .../ethernet/pensando/ionic/ionic_debugfs.c   |  34 ++
 .../ethernet/pensando/ionic/ionic_debugfs.h   |   2 +
 .../net/ethernet/pensando/ionic/ionic_dev.c   | 357 ++++++++++++++++++
 .../net/ethernet/pensando/ionic/ionic_dev.h   |  29 ++
 .../net/ethernet/pensando/ionic/ionic_if.h    |  86 +++++
 .../net/ethernet/pensando/ionic/ionic_lif.c   | 265 ++++++++-----
 .../net/ethernet/pensando/ionic/ionic_lif.h   |   7 +-
 .../net/ethernet/pensando/ionic/ionic_txrx.c  |  63 +++-
 .../net/ethernet/pensando/ionic/ionic_txrx.h  |   1 +
 11 files changed, 772 insertions(+), 100 deletions(-)

-- 
2.17.1