Re: [PATCH v3 16/19] nova-core: Add support for VBIOS ucode extraction for boot

[Timur Tabi <ttabi@nvidia.com>]

On Wed, 2025-05-07 at 22:52 +0900, Alexandre Courbot wrote:
> +impl FwSecBiosImage {
> +    fn setup_falcon_data(
> +        &mut self,
> +        pdev: &pci::Device,
> +        pci_at_image: &PciAtBiosImage,
> +        first_fwsec_image: &FwSecBiosImage,
> +    ) -> Result<()> {
> +        let mut offset = pci_at_image.falcon_data_ptr(pdev)? as usize;
> +
> +        // The falcon data pointer assumes that the PciAt and FWSEC images
> +        // are contiguous in memory. However, testing shows the EFI image sits in
> +        // between them. So calculate the offset from the end of the PciAt image
> +        // rather than the start of it. Compensate.
> +        offset -= pci_at_image.base.data.len();
> +
> +        // The offset is now from the start of the first Fwsec image, however
> +        // the offset points to a location in the second Fwsec image. Since
> +        // the fwsec images are contiguous, subtract the length of the first Fwsec
> +        // image from the offset to get the offset to the start of the second
> +        // Fwsec image.
> +        offset -= first_fwsec_image.base.data.len();
> +
> +        self.falcon_data_offset = Some(offset);
> +
> +        // The PmuLookupTable starts at the offset of the falcon data pointer
> +        self.pmu_lookup_table = Some(PmuLookupTable::new(&self.base.data[offset..])?);
> +
> +        match self
> +            .pmu_lookup_table
> +            .as_ref()
> +            .ok_or(EINVAL)?
> +            .find_entry_by_type(FALCON_UCODE_ENTRY_APPID_FWSEC_PROD)
> +        {
> +            Ok(entry) => {
> +                let mut ucode_offset = entry.data as usize;
> +                ucode_offset -= pci_at_image.base.data.len();
> +                ucode_offset -= first_fwsec_image.base.data.len();
> +                self.falcon_ucode_offset = Some(ucode_offset);
> +                if cfg!(debug_assertions) {
> +                    // Print the v3_desc header for debugging
> +                    let v3_desc = self.fwsec_header(pdev.as_ref())?;
> +                    pr_info!("PmuLookupTableEntry v3_desc: {:#?}\n", v3_desc);
> +                }
> +            }
> +            Err(e) => {
> +                dev_err!(
> +                    pdev.as_ref(),
> +                    "PmuLookupTableEntry not found, error: {:?}\n",
> +                    e
> +                );

Shouldn't you return an error here?

If not, then maybe this should probably be dev_warn.