[PATCH 00/14] can: m_can: Optimizations for m_can/tcan part 2

[Markus Schneider-Pargmann]

Hi Marc, Simon, Martin and everyone,

v7 is a rebase on v6.8. During my am62 tests I discovered some problems
which are fixed with this update.

@Simon: I had to remove most of your reviews again, due to a few
fixes I made.

The series implements many small and bigger throughput improvements and
adds rx/tx coalescing at the end.

Based on v6.8-rc1. Also available at
https://gitlab.baylibre.com/msp8/linux/-/tree/topic/mcan-optimization/v6.8?ref_type=heads

Best,
Markus

Changes in v7:
- Rebased to v6.8-rc1
- Fixed NULL pointer dereference in m_can_clean() on am62 that happened
  when doing ip link up, ip link down, ip link up
- Fixed a racecondition on am62 observed with high throughput tests.
  netdev_completed_queue() was called before netdev_sent_queue() as the
  interrupt was processed so fast. netdev_sent_queue() is now reported
  before the actual sent is done.
- Fixed an initializing issue on am62 where active interrupts are
  getting lost between runs. Fixed by resetting cdev->active_interrupts
  in m_can_disable_all_interrupts()
- Removed m_can_start_fast_xmit() because of a reordering of operations
  due to above mentioned racecondition

Changes in v6:
- Rebased to v6.6-rc2
- Added two small changes for the newly integrated polling feature
- Reuse the polling hrtimer for coalescing as the timer used for
  coalescing has a similar purpose as the one for polling. Also polling
  and coalescing will never be active at the same time.

Changes in v5:
- Add back parenthesis in m_can_set_coalesce(). This will make
  checkpatch unhappy but gcc happy.
- Remove unused fifo_header variable in m_can_tx_handler().
- Rebased to v6.5-rc1

Changes in v4:
- Create and use struct m_can_fifo_element in m_can_tx_handler
- Fix memcpy_and_pad to copy the full buffer
- Fixed a few checkpatch warnings
- Change putidx to be unsigned
- Print hard_xmit error only once when TX FIFO is full

Changes in v3:
- Remove parenthesis in error messages
- Use memcpy_and_pad for buffer copy in 'can: m_can: Write transmit
  header and data in one transaction'.
- Replace spin_lock with spin_lock_irqsave. I got a report of a
  interrupt that was calling start_xmit just after the netqueue was
  woken up before the locked region was exited. spin_lock_irqsave should
  fix this. I attached the full stack at the end of the mail if someone
  wants to know.
- Rebased to v6.3-rc1.
- Removed tcan4x5x patches from this series.

Changes in v2:
- Rebased on v6.2-rc5
- Fixed missing/broken accounting for non peripheral m_can devices.

previous versions:
v1 - https://lore.kernel.org/lkml/20221221152537.751564-1-msp@xxxxxxxxxxxx
v2 - https://lore.kernel.org/lkml/20230125195059.630377-1-msp@xxxxxxxxxxxx
v3 - https://lore.kernel.org/lkml/20230315110546.2518305-1-msp@xxxxxxxxxxxx/
v4 - https://lore.kernel.org/lkml/20230621092350.3130866-1-msp@xxxxxxxxxxxx/
v5 - https://lore.kernel.org/lkml/20230718075708.958094-1-msp@xxxxxxxxxxxx
v6 - https://lore.kernel.org/lkml/20230929141304.3934380-1-msp@xxxxxxxxxxxx

Markus Schneider-Pargmann (14):
  can: m_can: Start/Cancel polling timer together with interrupts
  can: m_can: Move hrtimer init to m_can_class_register
  can: m_can: Write transmit header and data in one transaction
  can: m_can: Implement receive coalescing
  can: m_can: Implement transmit coalescing
  can: m_can: Add rx coalescing ethtool support
  can: m_can: Add tx coalescing ethtool support
  can: m_can: Use u32 for putidx
  can: m_can: Cache tx putidx
  can: m_can: Use the workqueue as queue
  can: m_can: Introduce a tx_fifo_in_flight counter
  can: m_can: Use tx_fifo_in_flight for netif_queue control
  can: m_can: Implement BQL
  can: m_can: Implement transmit submission coalescing

 drivers/net/can/m_can/m_can.c          | 551 ++++++++++++++++++-------
 drivers/net/can/m_can/m_can.h          |  34 +-
 drivers/net/can/m_can/m_can_platform.c |   4 -
 3 files changed, 439 insertions(+), 150 deletions(-)

-- 
2.43.0