Commit 56bb4b17 authored by Alexandre Courbot's avatar Alexandre Courbot
Browse files

gpu: nova-core: vbios: use FromBytes for PcirStruct 



Use `from_bytes_copy_prefix` to create `PcirStruct` instead of building
it ourselves from the bytes stream. This lets us remove a few array
accesses and results in shorter code.

Reviewed-by: default avatarJoel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251029-nova-vbios-frombytes-v1-3-ac441ebc1de3@nvidia.com>
parent 7f74842d

drivers/gpu/nova-core/vbios.rs

+12 −28
Original line number Diff line number Diff line
@@ -314,45 +314,29 @@ struct PcirStruct { 
    max_runtime_image_len: u16,

}



// SAFETY: all bit patterns are valid for `PcirStruct`.

unsafe impl FromBytes for PcirStruct {}



impl PcirStruct {

    fn new(dev: &device::Device, data: &[u8]) -> Result<Self> {

        if data.len() < core::mem::size_of::<PcirStruct>() {

            dev_err!(dev, "Not enough data for PcirStruct\n");

            return Err(EINVAL);

        }



        let mut signature = [0u8; 4];

        signature.copy_from_slice(&data[0..4]);

        let (pcir, _) = PcirStruct::from_bytes_copy_prefix(data).ok_or(EINVAL)?;



        // Signature should be "PCIR" (0x52494350) or "NPDS" (0x5344504e).

        if &signature != b"PCIR" && &signature != b"NPDS" {

            dev_err!(dev, "Invalid signature for PcirStruct: {:?}\n", signature);

        if &pcir.signature != b"PCIR" && &pcir.signature != b"NPDS" {

            dev_err!(

                dev,

                "Invalid signature for PcirStruct: {:?}\n",

                pcir.signature

            );

            return Err(EINVAL);

        }



        let mut class_code = [0u8; 3];

        class_code.copy_from_slice(&data[13..16]);



        let image_len = u16::from_le_bytes([data[16], data[17]]);

        if image_len == 0 {

        if pcir.image_len == 0 {

            dev_err!(dev, "Invalid image length: 0\n");

            return Err(EINVAL);

        }



        Ok(PcirStruct {

            signature,

            vendor_id: u16::from_le_bytes([data[4], data[5]]),

            device_id: u16::from_le_bytes([data[6], data[7]]),

            device_list_ptr: u16::from_le_bytes([data[8], data[9]]),

            pci_data_struct_len: u16::from_le_bytes([data[10], data[11]]),

            pci_data_struct_rev: data[12],

            class_code,

            image_len,

            vendor_rom_rev: u16::from_le_bytes([data[18], data[19]]),

            code_type: data[20],

            last_image: data[21],

            max_runtime_image_len: u16::from_le_bytes([data[22], data[23]]),

        })

        Ok(pcir)

    }



    /// Check if this is the last image in the ROM.