[v5,0/6] firmware_loader: cleanups for v4.18

Greg,

I've reviewed the pending patches for the firmware_laoder and as for
v4.18, the following 3 patches from Andres have been iterated enough
that they're ready after I made some final minor changes, mostly just
style fixes and re-arrangements in terms of order. The new API he was
suggesting to add requires just a bit more review.

The last 3 patches are my own and are new, so I'd like further review
from others on them, but considering the changes Hans de Goede is having
us consider, I think this will prove useful to his work in terms of
splitting up code and documenting things properly. One thing that was
clear -- is our Kconfig entries for FW_LOADER were *extremely* outdated,
as such I've gone ahead and updated them.

The kconfig wording update for FW_LOADER includes prior conclusions made
to help justify keeping the split of the firmware fallback sysfs
interface in terms of size which was discussed with Josh Triplett a
while ago. It also includes modern recommendations, which would otherwise
get lost, on what to do about corner case firmware situations on
provisioning situations which folks have brought to my attention before
and architectural solutions based on firmwared [0] for a few years now.
Finally this work also reveals that a couple of candidate drivers could
likely move to staging considering their age, *or* we could just remove
the respective firmware build options. SCSI folks? Networking folks? To
my surprise *nothing* has been done about PREVENT_FIRMWARE_BUILD for
them since pre-git days!  These sneaky litte buggers are:

  * CONFIG_WANXL --> CONFIG_WANXL_BUILD_FIRMWARE
  * CONFIG_SCSI_AIC79XX --> CONFIG_AIC79XX_BUILD_FIRMWARE

To this day both of these drivers are building driver *firmwares* when
the option CONFIG_PREVENT_FIRMWARE_BUILD is disabled, and they don't
even make use of the firmware API at all. I find it *highly unlikely*
pre-git day drivers are raging in new radical firmware updates these
days. I'll go put a knife into some of that unless I hear back from
SCSI or networking folks that WANXL_BUILD_FIRMWARE and
AIC79XX_BUILD_FIRMWARE are still hip and very much needed.

On my radar as well are Mimi's latest firmware_loader proposed changes,
but I think those need considerable review and attention from more security
folks, Android folks, and the linux-wireless community, our own
scattered random folks of firmware reviewer folks.

These patches are based on top of linux-next next-20180504, they are
also available in a respective git branch, both for linux-next [1] and
linux [2].

Question, and specially rants are greatly appreciated, and of course...
may the 4th be with you.

[0] https://github.com/teg/firmwared
[1] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=20180504-firmware_loader
[2] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=20180504-firmware_loader

  Luis

Andres Rodriguez (3):
  firmware: wrap FW_OPT_* into an enum
  firmware: use () to terminate kernel-doc function names
  firmware: rename fw_sysfs_fallback to firmware_fallback_sysfs()

Luis R. Rodriguez (3):
  firmware_loader: document firmware_sysfs_fallback()
  firmware_loader: enhance Kconfig documentation over FW_LOADER
  firmware_loader: move kconfig FW_LOADER entries to its own file

 drivers/base/Kconfig                    |  90 +++-----------
 drivers/base/firmware_loader/Kconfig    | 149 ++++++++++++++++++++++++
 drivers/base/firmware_loader/fallback.c |  46 +++++---
 drivers/base/firmware_loader/fallback.h |  18 +--
 drivers/base/firmware_loader/firmware.h |  37 ++++--
 drivers/base/firmware_loader/main.c     |  28 ++---
 6 files changed, 252 insertions(+), 116 deletions(-)
 create mode 100644 drivers/base/firmware_loader/Kconfig

"Luis R. Rodriguez" <mcgrof@kernel.org> writes:

>   * CONFIG_WANXL --> CONFIG_WANXL_BUILD_FIRMWARE
>   * CONFIG_SCSI_AIC79XX --> CONFIG_AIC79XX_BUILD_FIRMWARE
>
> To this day both of these drivers are building driver *firmwares* when
> the option CONFIG_PREVENT_FIRMWARE_BUILD is disabled, and they don't
> even make use of the firmware API at all.

Don't know for sure about Adaptec, but wanXL firmware fits every
definition of "stable". BTW it's a 1997 or so early PCI card, built
around the PLX PCI9060 bus mastering PCI bridge and Motorola 68360
(the original QUICC) processor. Maximum bit rate of 2 Mb/s on each sync
serial port.

It's more about delivering the .S source for the firmware, I guess.
Nobody is expected to build it. The fw is about 2.5 KB and is directly
linked with the driver.

On Fri, May 04, 2018 at 09:17:08PM +0200, Krzysztof Halasa wrote:
> "Luis R. Rodriguez" <mcgrof@kernel.org> writes:
> 
> >   * CONFIG_WANXL --> CONFIG_WANXL_BUILD_FIRMWARE
> >   * CONFIG_SCSI_AIC79XX --> CONFIG_AIC79XX_BUILD_FIRMWARE
> >
> > To this day both of these drivers are building driver *firmwares* when
> > the option CONFIG_PREVENT_FIRMWARE_BUILD is disabled, and they don't
> > even make use of the firmware API at all.
> 
> Don't know for sure about Adaptec, but wanXL firmware fits every
> definition of "stable". BTW it's a 1997 or so early PCI card, built
> around the PLX PCI9060 bus mastering PCI bridge and Motorola 68360
> (the original QUICC) processor. Maximum bit rate of 2 Mb/s on each sync
> serial port.

So we can nuke CONFIG_WANXL_BUILD_FIRMWARE now?

> It's more about delivering the .S source for the firmware, I guess.
> Nobody is expected to build it. The fw is about 2.5 KB and is directly
> linked with the driver.

:P Future work I guess would be to just use the firmware API and stuff
it into linux-firmware?

  Luis

"Luis R. Rodriguez" <mcgrof@kernel.org> writes:

> So we can nuke CONFIG_WANXL_BUILD_FIRMWARE now?

I'm uncertain I understand why do you want it, or maybe what are you
trying to do at all.

And what use would wanxlfw.S (the assembly source) have if the option is
removed?

>> It's more about delivering the .S source for the firmware, I guess.
>> Nobody is expected to build it. The fw is about 2.5 KB and is directly
>> linked with the driver.
>
> :P Future work I guess would be to just use the firmware API and stuff
> it into linux-firmware?

Who's going to make it happen?
The last time I checked (several years ago), wanXL worked. Who's going
to test it after the change?

I assume linux-firmware could include fw source and there would be means
to build the binary.

Just to be sure: the wanXL firmware has exactly nothing to do with FW
loader, nothing depends on it (nor the other way around), it's just
(with the rest of the wanXL code) an old piece of a driver for an old
card.

The question is, what do we gain by messing with it?

On Fri, May 04, 2018 at 10:43:49AM -0700, Luis R. Rodriguez wrote:
> Greg,
> 
> I've reviewed the pending patches for the firmware_laoder and as for
> v4.18, the following 3 patches from Andres have been iterated enough
> that they're ready after I made some final minor changes, mostly just
> style fixes and re-arrangements in terms of order. The new API he was
> suggesting to add requires just a bit more review.

We're done with review of the new API for the sync no warn call,
so I'll just re-issue another patch series with those patches
in a new series.

Coming right up.

  Luis