kernel/kernel-modules/bnxt_en/centos
M. Vefa Bicakci 0ae9f6bd53 Add Broadcom NetXtreme-E drivers
This commit introduces Broadcom's bnxt_en and bnxt_re out-of-tree
drivers, version 220.0.13.0, to StarlingX, and disables the in-tree
bnxt_en driver. (For clarity, the main driver package file name is
"bcm_220.0.83.0.tar.gz".)

There is a need to build Broadcom's driver against the version of the
Infiniband/RDMA code base bundled with Mellanox OFED (OpenFabrics
Enterprise Distribution), because the in-tree kernel Infiniband/RDMA
modules are disabled, and Mellanox OFED's out-of-tree Infiniband/RDMA
modules replace the in-tree versions.

A custom spec file was used, despite the fact that the Broadcom device
driver package includes a source RPM file. This was necessary due to two
reasons:

- The source RPM file has whitespace between its field labels (such as
  Name, Version, Release, and so on) and the values of these fields.
  (Example: "Name   :  bnxt_en") This unfortunately breaks "build-pkgs
  --edit", which cannot handle the whitespace during the extraction of
  the source RPM.

- More importantly, the spec file included by Broadcom has the following
  lines in its %prep section, which does not use the %setup macro:

  %prep
  #%setup
  mkdir -p source
  tar -xzvf %{SOURCE0} -C source/
  mv -f source/netxtreme-%name-%{version}-220.0.13.0/* source/
  rm -rf source/netxtreme-%name-%{version}-220.0.13.0/
  cp ./source/%{bnxt_re_driver}/README.TXT
  ./source/%{bnxt_re_driver}/%{bnxt_re_driver}_README.TXT
  cp ./source/%{bnxt_en_driver}/README.TXT
  ./source/%{bnxt_en_driver}/%{bnxt_en_driver}_README.TXT
  mkdir -p obj

  This is problematic, because the "build-pkgs --edit" procedure
  extracts the source RPM multiple times into the same directory to
  ensure that the extraction is stable. However, the %prep section
  quoted above does not remove the 'source' directory before attempting
  to populate it. (Unfortunately, this issue is not patchable using a
  meta-patch, because the extraction occurs even before the application
  of meta-patches.) This in turn triggers the following errors:

  + mv -f source/netxtreme-bnxt_en-1.10.2-220.0.13.0/Makefile \
    source/netxtreme-bnxt_en-1.10.2-220.0.13.0/bnxt_en \
    source/netxtreme-bnxt_en-1.10.2-220.0.13.0/bnxt_en-1.10.2-220.0.13.0 \
    source/netxtreme-bnxt_en-1.10.2-220.0.13.0/bnxt_re \
    source/netxtreme-bnxt_en-1.10.2-220.0.13.0/bnxt_re-220.0.12.0 \
    source/
  mv: cannot move 'source/netxtreme-bnxt_en-1.10.2-220.0.13.0/bnxt_en-1.10.2-220.0.13.0' \
    to 'source/bnxt_en-1.10.2-220.0.13.0': Directory not empty
  mv: cannot move 'source/netxtreme-bnxt_en-1.10.2-220.0.13.0/bnxt_re-220.0.12.0' \
    to 'source/bnxt_re-220.0.12.0': Directory not empty
  error: Bad exit status from .../std/srpm_work/bnxt_en/var/tmp/rpm-tmp.cDTpOP (%prep)
      Bad exit status from .../std/srpm_work/bnxt_en/var/tmp/rpm-tmp.cDTpOP (%prep)

The changes made to the spec file are as follows:

- Reliance on Red Hat's kernel module packaging RPM spec macros (such as
  %kernel_module_package) is removed, because the aforementioned macros
  make use of the kmodtool helper program, which automatically generates
  an RPM post-installation and post-uninstallation sections making use
  of the weak-modules utility, which StarlingX does not use/support. It
  is not possible to disable this behaviour of the kmodtool script
  ("/usr/lib/rpm/redhat/kmodtool") with a command line option or an
  environment variable.

- The spec file is reorganized to build the kernel module against only a
  single kernel "flavour", as StarlingX does not use the kernel flavour
  concept.

- The %build process is modified so that instead of using the top-level
  makefile (which does not take certain variables as arguments), the
  bnxt_en- and bnxt_re-specific makefiles are called with make
  separately. This allows passing KDIR, KVER and OFED_VERSION make
  variables as command line arguments to make.

- The use of the devtoolset-8 software collection was added to align to
  the kernel's build toolchain.

- The spec file is modified to detect the OFED version and pass the
  version to the bnxt_re makefile as the OFED_VERSION environment
  variable. This is necessary to automatically adapt to the version of
  OFED installed in the build environment.

- The %post and %postun scriptlets are modified to make them similar to
  the ones used by i40e, which passes the target kernel's version to
  depmod. The original %post only had 'depmod -a', which can be
  problematic when installing the package for a kernel that is not
  currently running.

- Kernel module signing was added to %install. This shell snippet was
  adapted from i40e.

- Finally, retpolines were enabled by default, given that StarlingX
  enables retpolines in its kernel packages as well.

In terms of source code modifications, the following changes were made
to bnxt_en and bnxt_re:

- The bnxt_en and bnxt_re kernel modules are patched to make use of the
  irq_update_affinity_hint function instead of the irq_set_affinity_hint
  function, so that the irqaffinity= kernel command line option takes
  effect for the affinities of the IRQs managed by the two drivers.

  However, it should be noted the changes in bnxt_en are not truly
  necessary, because pre-existing conditional compilation directives
  leave out the modified code when targeting kernels >= v4.15 or kernels
  that have the "IRQ matrix allocator" feature. The changes are kept for
  completeness, nevertheless.

  For further details, please see the patch description.

- A compilation failure caused by the definition of a placeholder macro
  aimed to stand in for the bpf_warn_invalid_xdp_action function in the
  kernel tree is resolved by removing the macro definition.

Testing:
- An ISO image was successfully built with a monolithic incremental
  build procedure.

- Using a virtual machine in All-in-One simplex configuration, the
  bnxt_en and bnxt_re kernel modules were confirmed to be successfully
  loaded manually using, for example, "modprobe -v -a bnxt_en bnxt_re".
  Runtime tests for these drivers were unfortunately very limited,
  because the necessary hardware has not yet been acquired. We intend to
  resolve integration issues when hardware is acquired.

Story: 2009915
Task: 44762

Depends-On: https://review.opendev.org/c/starlingx/kernel/+/833463
Depends-On: https://review.opendev.org/c/starlingx/tools/+/833462

Change-Id: Ieb4147335410160a781382b0b6b01e2015468a3b
Signed-off-by: M. Vefa Bicakci <vefa.bicakci@windriver.com>
2022-03-23 10:21:10 -04:00
..
patches Add Broadcom NetXtreme-E drivers 2022-03-23 10:21:10 -04:00
bnxt_en.spec Add Broadcom NetXtreme-E drivers 2022-03-23 10:21:10 -04:00
build_srpm.data Add Broadcom NetXtreme-E drivers 2022-03-23 10:21:10 -04:00