[PATCH v4 00/20] gpu: nova-core: vbios: harden various array accesses and refactor

[Eliot Courtney <ecourtney@nvidia.com>]

We have some code that accesses arrays based on values from firmware.
This patch series makes a bunch of those accesses more robust. This
series only touches accesses that are not guaranteed to be safe by local
invariants - some accesses are safe due to earlier checks and I haven't
modified those.

This series also refactors and removes some code that can be simplified.
In particular, it removes `FwSecBiosBuilder`, removes unused fields,
and moves type and constant definitions closer to their usages.

Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
Changes in v4:
- Split BIOS_MAX_SCAN_LEN patch into multiple per review comments
- Consolidate bios max scan length checking
- Convert more structs to use FromBytes since we assume little endian
- Remove unused PciRomHeader fields
- Drop unused types / imports
- Move constants+helpers closer to usage locations
- Link to v3: https://patch.msgid.link/20260421-fix-vbios-v3-0-8f648aef7a85@nvidia.com

Changes in v3:
- Use first PCI-AT and FWSEC images instead of erroring.
- Expand commit messages.
- Add Joel's Reviewed-by's (thanks!)
- Link to v2: https://patch.msgid.link/20260414-fix-vbios-v2-0-705d30d16bba@nvidia.com

Changes in v2:
- Add Joel's reviewed-by tags.
- Remove unnecessary code like `falcon_data_offset` from
  `FwSecBiosBuilder`
- Push offset handling into `falcon_data_ptr` (renamed)
- Simplify `setup_falcon_data`
- Add checking for spurious PCI-AT and FWSEC images.
- Remove `FwSecBiosBuilder`
- Link to v1: https://patch.msgid.link/20260410-fix-vbios-v1-0-bc6f71d153d6@nvidia.com

---
Eliot Courtney (20):
      gpu: nova-core: vbios: stop scanning at BIOS_MAX_SCAN_LEN
      gpu: nova-core: vbios: use checked arithmetic for bios image range end
      gpu: nova-core: vbios: avoid reading too far in read_more_at_offset
      gpu: nova-core: vbios: read BitToken using FromBytes
      gpu: nova-core: vbios: use checked ops and accesses in `FwSecBiosImage::ucode`
      gpu: nova-core: vbios: use checked access in `FwSecBiosImage::header`
      gpu: nova-core: vbios: use checked accesses in `setup_falcon_data`
      gpu: nova-core: vbios: drop unused falcon_data_offset from FwSecBiosBuilder
      gpu: nova-core: vbios: keep PmuLookupTable local in setup_falcon_data
      gpu: nova-core: vbios: compute FWSEC-relative Falcon data offset
      gpu: nova-core: vbios: simplify setup_falcon_data
      gpu: nova-core: vbios: read PMU lookup entries using FromBytes
      gpu: nova-core: vbios: store PMU lookup entries in a KVVec
      gpu: nova-core: vbios: construct `FwSecBiosImage` directly from BIOS images
      gpu: nova-core: vbios: use the first PCI-AT and FWSEC images
      gpu: nova-core: vbios: use let-else in Vbios::new
      gpu: nova-core: vbios: remove unnecessary fields in PciRomHeader
      gpu: nova-core: vbios: drop unused image wrappers
      gpu: nova-core: vbios: drop redundant TryFrom import
      gpu: nova-core: vbios: move constants and functions to be associated

 Documentation/gpu/nova/core/vbios.rst |   2 +-
 drivers/gpu/nova-core/vbios.rs        | 658 ++++++++++++++--------------------
 2 files changed, 267 insertions(+), 393 deletions(-)
---
base-commit: 8bfe9d72cf2064f679c4192dba84be79eb70675d
change-id: 20260409-fix-vbios-d668e9c21d23

Best regards,
--  
Eliot Courtney <ecourtney@nvidia.com>