[PATCH v2 0/5] gpu: nova-core: run unload sequence upon unbinding

[Alexandre Courbot <acourbot@nvidia.com>]

Currently the GSP is left running and the WPR2 memory region untouched
when the driver is unbound. This is obviously not ideal for at least two
reasons:

- Probing requires setting up the WPR2 region, which cannot be done if
  there is already one in place. Hence the current requirement to reset
  the GPU (using e.g. `echo 1 >/sys/bus/pci/devices/.../reset`) before
  the driver can be probed again after removal.
- The running GSP may still attempt to access shared memory regions
  which the kernel might recycle.

On top of that, there is a nasty bug in the Blackwell VBIOS that
sometimes borks the GPU upon PCI reset, requiring a reboot. So relying
on the PCI reset to unload/reload Nova is really not practical here.

This series does the necessary to leave the GPU in a clean state after
unbind, for all currently supported GPUs. Blackwell support is trivial
and will be added alongside the Blackwell series [1] if this can be
merged first.

The first patch adds a `warn_on_err` utility macro to the kernel crate
as it is useful to warn on failures in the driver unbind path, but I can
remove it if it is not deemed useful.

This series applies cleanly on `master` as of today.

[1] https://lore.kernel.org/all/20260411024953.473149-1-jhubbard@nvidia.com/

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
Changes in v2:
- Rebase on top of `master` and remove unneeded/obsolete preparatory patches.
- Tidy up the imports of commands from the `fw` module in the `gsp` module.
- Link to v1: https://patch.msgid.link/20251216-nova-unload-v1-0-6a5d823be19d@nvidia.com

---
Alexandre Courbot (5):
      rust: add warn_on_err macro
      gpu: nova-core: use warn_on_err macro
      gpu: nova-core: do not import firmware commands into GSP command module
      gpu: nova-core: send UNLOADING_GUEST_DRIVER GSP command upon unloading
      gpu: nova-core: run Booter Unloader and FWSEC-SB upon unbinding

 drivers/gpu/nova-core/firmware/booter.rs          |  1 -
 drivers/gpu/nova-core/firmware/fwsec.rs           |  1 -
 drivers/gpu/nova-core/gpu.rs                      | 21 ++++--
 drivers/gpu/nova-core/gsp/boot.rs                 | 83 +++++++++++++++++++++++
 drivers/gpu/nova-core/gsp/commands.rs             | 60 ++++++++++++----
 drivers/gpu/nova-core/gsp/fw.rs                   |  4 ++
 drivers/gpu/nova-core/gsp/fw/commands.rs          | 23 +++++++
 drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs |  8 +++
 drivers/gpu/nova-core/regs.rs                     |  5 ++
 rust/kernel/bug.rs                                | 10 +++
 10 files changed, 197 insertions(+), 19 deletions(-)
---
base-commit: b4e07588e743c989499ca24d49e752c074924a9a
change-id: 20251216-nova-unload-4029b3b76950

Best regards,
--  
Alexandre Courbot <acourbot@nvidia.com>