Subject: Re: [net-next 0/6] net: marvell: prestera: Add Switchdev driver for Prestera family ASIC device 98DX326x (AC3x)

From: Ido Schimmel <[email-masked]>
Date: Sat, 30 May 2020 18:54:29 +0300

On Sat, May 30, 2020 at 05:52:31PM +0300, Vadym Kochan wrote:
> Hi Ido,
> 
> On Sat, May 30, 2020 at 05:29:28PM +0300, Ido Schimmel wrote:
> > On Thu, May 28, 2020 at 06:12:39PM +0300, Vadym Kochan wrote:
> > > Marvell Prestera 98DX326x integrates up to 24 ports of 1GbE with 8
> > > ports of 10GbE uplinks or 2 ports of 40Gbps stacking for a largely
> > > wireless SMB deployment.
> > > 
> > > Prestera Switchdev is a firmware based driver that operates via PCI bus.  The
> > > current implementation supports only boards designed for the Marvell Switchdev
> > > solution and requires special firmware.
> > > 
> > > This driver implementation includes only L1, basic L2 support, and RX/TX.
> > > 
> > > The core Prestera switching logic is implemented in prestera_main.c, there is
> > > an intermediate hw layer between core logic and firmware. It is
> > > implemented in prestera_hw.c, the purpose of it is to encapsulate hw
> > > related logic, in future there is a plan to support more devices with
> > > different HW related configurations.
> > > 
> > > The following Switchdev features are supported:
> > > 
> > >     - VLAN-aware bridge offloading
> > >     - VLAN-unaware bridge offloading
> > >     - FDB offloading (learning, ageing)
> > >     - Switchport configuration
> > > 
> > > The firmware image will be uploaded soon to the linux-firmware repository.
> > > 
> > > PATCH:
> > >     1) Fixed W=1 warnings
> > 
> > Hi,
> > 
> > I just applied the patches for review and checkpatch had a lot of
> > complaints. Some are even ERRORs. For example:
> > 
> > WARNING: do not add new typedefs
> > #1064: FILE: drivers/net/ethernet/marvell/prestera/prestera_hw.h:32:
> > +typedef void (*prestera_event_cb_t)
> I may be wrong, as I remember Jiri suggested it and looks like
> it makes sense. I really don't have strong opinion about this.

OK, so I'll let Jiri comment when he is back at work.

> 
> > 
> > WARNING: line over 80 characters
> > #2007: FILE: drivers/net/ethernet/marvell/prestera/prestera_rxtx.c:321:
> > +                       __skb_trim(buf->skb, PRESTERA_SDMA_RX_DESC_PKT_LEN(desc));
> > 
> > WARNING: line over 80 characters
> > #2007: FILE: drivers/net/ethernet/marvell/prestera/prestera_rxtx.c:321:
> > +                       __skb_trim(buf->skb, PRESTERA_SDMA_RX_DESC_PKT_LEN(desc));
> > 
> > ERROR: Macros with complex values should be enclosed in parentheses
> > #196: FILE: drivers/net/ethernet/marvell/prestera/prestera_pci.c:161:
> > +#define PRESTERA_FW_REG_ADDR(fw, reg)  PRESTERA_FW_REG_BASE(fw) + (reg)
> This one makes sense.
> > 
> > WARNING: prefer 'help' over '---help---' for new help texts
> > #52: FILE: drivers/net/ethernet/marvell/prestera/Kconfig:15:
> > +config PRESTERA_PCI
> I will fix it.
> > 
> > ...
> 
> The most are about using ethtool types which are in camel style.
> Regarding > 80 chars is is a required rule ? I saw some discussion
> on LKML that 80+ are acceptable sometimes.

Yea, that's why I didn't include them. Error messages can always exceed
80 characters. Other times I try to follow the rule unless
"the cure is worse than the disease":

https://www.mail-archive.com/[email-masked]/msg1818701.html

> 
> > 
> > Also, smatch complaints about:
> > 
> > drivers/net/ethernet/marvell/prestera//prestera_ethtool.c:713
> > prestera_ethtool_get_strings() error: memcpy() '*prestera_cnt_name' too
> > small (32 vs 960)
> > 
> > And coccicheck about:
> > 
> > drivers/net/ethernet/marvell/prestera/prestera_hw.c:681:2-3: Unneeded
> > semicolon
> These looks interesting, I did not use smatch and coccicheck, will look
> on these.
> 
> > 
> > > 
> > >     2) Renamed PCI driver name to be more generic "Prestera DX" because
> > >        there will be more devices supported.
> > > 
> > >     3) Changed firmware image dir path: marvell/ -> mrvl/prestera/
> > >        to be aligned with location in linux-firmware.git (if such
> > >        will be accepted).
> > > 
> > > RFC v3:
> > >     1) Fix prestera prefix in prestera_rxtx.c
> > > 
> > >     2) Protect concurrent access from multiple ports on multiple CPU system
> > >        on tx path by spinlock in prestera_rxtx.c
> > > 
> > >     3) Try to get base mac address from device-tree, otherwise use a random generated one.
> > > 
> > >     4) Move ethtool interface support into separate prestera_ethtool.c file.
> > > 
> > >     5) Add basic devlink support and get rid of physical port naming ops.
> > > 
> > >     6) Add STP support in Switchdev driver.
> > > 
> > >     7) Removed MODULE_AUTHOR
> > > 
> > >     8) Renamed prestera.c -> prestera_main.c, and kernel module to
> > >        prestera.ko
> > > 
> > > RFC v2:
> > >     1) Use "pestera_" prefix in struct's and functions instead of mvsw_pr_
> > > 
> > >     2) Original series split into additional patches for Switchdev ethtool support.
> > > 
> > >     3) Use major and minor firmware version numbers in the firmware image filename.
> > > 
> > >     4) Removed not needed prints.
> > > 
> > >     5) Use iopoll API for waiting on register's value in prestera_pci.c
> > > 
> > >     6) Use standart approach for describing PCI ID matching section instead of using
> > >        custom wrappers in prestera_pci.c
> > > 
> > >     7) Add RX/TX support in prestera_rxtx.c.
> > > 
> > >     8) Rewritten prestera_switchdev.c with following changes:
> > >        - handle netdev events from prestera.c
> > > 
> > >        - use struct prestera_bridge for bridge objects, and get rid of
> > >          struct prestera_bridge_device which may confuse.
> > > 
> > >        - use refcount_t
> > > 
> > >     9) Get rid of macro usage for sending fw requests in prestera_hw.c
> > > 
> > >     10) Add base_mac setting as module parameter. base_mac is required for
> > >         generation default port's mac.
> > > 
> > > Vadym Kochan (6):
> > >   net: marvell: prestera: Add driver for Prestera family ASIC devices
> > >   net: marvell: prestera: Add PCI interface support
> > >   net: marvell: prestera: Add basic devlink support
> > >   net: marvell: prestera: Add ethtool interface support
> > >   net: marvell: prestera: Add Switchdev driver implementation
> > >   dt-bindings: marvell,prestera: Add description for device-tree
> > >     bindings
> > > 
> > >  .../bindings/net/marvell,prestera.txt         |   34 +
> > >  drivers/net/ethernet/marvell/Kconfig          |    1 +
> > >  drivers/net/ethernet/marvell/Makefile         |    1 +
> > >  drivers/net/ethernet/marvell/prestera/Kconfig |   25 +
> > >  .../net/ethernet/marvell/prestera/Makefile    |    7 +
> > >  .../net/ethernet/marvell/prestera/prestera.h  |  208 +++
> > >  .../marvell/prestera/prestera_devlink.c       |  111 ++
> > >  .../marvell/prestera/prestera_devlink.h       |   25 +
> > >  .../ethernet/marvell/prestera/prestera_dsa.c  |  134 ++
> > >  .../ethernet/marvell/prestera/prestera_dsa.h  |   37 +
> > >  .../marvell/prestera/prestera_ethtool.c       |  737 ++++++++++
> > >  .../marvell/prestera/prestera_ethtool.h       |   37 +
> > >  .../ethernet/marvell/prestera/prestera_hw.c   | 1225 ++++++++++++++++
> > >  .../ethernet/marvell/prestera/prestera_hw.h   |  180 +++
> > >  .../ethernet/marvell/prestera/prestera_main.c |  663 +++++++++
> > >  .../ethernet/marvell/prestera/prestera_pci.c  |  825 +++++++++++
> > >  .../ethernet/marvell/prestera/prestera_rxtx.c |  860 +++++++++++
> > >  .../ethernet/marvell/prestera/prestera_rxtx.h |   21 +
> > >  .../marvell/prestera/prestera_switchdev.c     | 1286 +++++++++++++++++
> > >  .../marvell/prestera/prestera_switchdev.h     |   16 +
> > >  20 files changed, 6433 insertions(+)
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/Kconfig
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/Makefile
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera.h
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_devlink.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_devlink.h
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_dsa.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_dsa.h
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_ethtool.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_ethtool.h
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_hw.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_hw.h
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_main.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_pci.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_rxtx.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_rxtx.h
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
> > >  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_switchdev.h
> > > 
> > > -- 
> > > 2.17.1
> > >