[PATCH v6 0/4] report the controller capabilities through the netlink interface

From: Vincent Mailhol
Date: Mon Dec 13 2021 - 11:02:54 EST


The main purpose of this series is to report the CAN controller
capabilities. The proposed method reuses the existing struct
can_ctrlmode and thus do not need a new IFLA_CAN_* entry.

While doing so, I also realized that can_priv::ctrlmode_static could
actually be derived from the other ctrlmode fields. So I added three
extra patches to the series: one to replace that field with a
function, one to add a safeguard on can_set_static_ctrlmode() and one
to repack struct can_priv and fill the hole created after removing
can_priv::ctrlmode_priv.

Please note that the first three patches are not required by the
fourth one. I am just grouping everything in the same series because
the patches all revolve around the controller modes.


** Changelog **

v5 -> v6:

- Add back patches 1, 2 and 3 because those were removed from the
testing branch of linux-can-next since.

- Rebase the series on the latest version of net-next.

- Fix a typo in the comments of the forth patch: guaruanty ->
guaranty.

v4 -> v5:

- Implement IFLA_CAN_CTRLMODE_EXT in order to fix forward
compatibility issues as suggested by Marc in:
https://lore.kernel.org/linux-can/20211029124608.u7zbprvojifjpa7j@xxxxxxxxxxxxxx/T/#m78118c94072083a6f8d2f0f769b120f847ac1384

v3 -> v4:

- Tag the union in struct can_ctrlmode as packed.

- Remove patch 1, 2 and 3 from the series because those were already
added to the testing branch of linux-can-next (and no changes
occurred on those first three patches).

v2 -> v3:

- Make can_set_static_ctrlmode() return an error and adjust the
drivers which use this helper function accordingly.

v1 -> v2:

- Add a first patch to replace can_priv::ctrlmode_static by the
inline function can_get_static_ctrlmode()

- Add a second patch to reorder the fields of struct can_priv for
better packing (save eight bytes on x86_64 \o/)

- Rewrite the comments of the third patch "can: netlink: report the
CAN controller mode supported flags" (no changes on the code
itself).

Vincent Mailhol (4):
can: dev: replace can_priv::ctrlmode_static by
can_get_static_ctrlmode()
can: dev: add sanity check in can_set_static_ctrlmode()
can: dev: reorder struct can_priv members for better packing
can: netlink: report the CAN controller mode supported flags

drivers/net/can/dev/dev.c | 5 +++--
drivers/net/can/dev/netlink.c | 33 +++++++++++++++++++++++++++++--
drivers/net/can/m_can/m_can.c | 10 +++++++---
drivers/net/can/rcar/rcar_canfd.c | 4 +++-
include/linux/can/dev.h | 24 +++++++++++++++-------
include/uapi/linux/can/netlink.h | 13 ++++++++++++
6 files changed, 74 insertions(+), 15 deletions(-)


base-commit: 64445dda9d8384975eca54e3f01886fca61e1db6
prerequisite-patch-id: 84ffb60366d113cfbf6fb8e415217d9e09fadefd
--
2.32.0