Commit e10dcb9d authored by Alexandre Courbot's avatar Alexandre Courbot
Browse files

gpu: nova-core: firmware: gsp: use dma::Coherent for level0 table 



Replace the nova-core local `DmaObject` with a `CoherentBox` that can
fulfill the same role.

Since `CoherentBox` is more flexible than `DmaObject`, we can use the
native `u64` type for page table entries instead of messing with bytes.

The `dma` module becomes unused with that change, so remove it as well.

Reviewed-by: default avatarGary Guo <gary@garyguo.net>
Reviewed-by: default avatarDanilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260327-b4-nova-dma-removal-v2-7-616e1d0b5cb3@nvidia.com


Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
parent 371db8bc

drivers/gpu/nova-core/dma.rs

deleted100644 → 0
+0 −53
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



//! Simple DMA object wrapper.



use core::ops::{

    Deref,

    DerefMut, //

};



use kernel::{

    device,

    dma::Coherent,

    page::PAGE_SIZE,

    prelude::*, //

};



pub(crate) struct DmaObject {

    dma: Coherent<[u8]>,

}



impl DmaObject {

    pub(crate) fn new(dev: &device::Device<device::Bound>, len: usize) -> Result<Self> {

        let len = core::alloc::Layout::from_size_align(len, PAGE_SIZE)

            .map_err(|_| EINVAL)?

            .pad_to_align()

            .size();

        let dma = Coherent::zeroed_slice(dev, len, GFP_KERNEL)?;



        Ok(Self { dma })

    }



    pub(crate) fn from_data(dev: &device::Device<device::Bound>, data: &[u8]) -> Result<Self> {

        let dma_obj = Self::new(dev, data.len())?;

        // SAFETY: We have just allocated the DMA memory, we are the only users and

        // we haven't made the device aware of the handle yet.

        unsafe { dma_obj.as_mut()[..data.len()].copy_from_slice(data) };

        Ok(dma_obj)

    }

}



impl Deref for DmaObject {

    type Target = Coherent<[u8]>;



    fn deref(&self) -> &Self::Target {

        &self.dma

    }

}



impl DerefMut for DmaObject {

    fn deref_mut(&mut self) -> &mut Self::Target {

        &mut self.dma

    }

}

drivers/gpu/nova-core/firmware/gsp.rs

+12 −10
Original line number Diff line number Diff line
@@ -4,10 +4,10 @@ 
    device,

    dma::{

        Coherent,

        CoherentBox,

        DataDirection,

        DmaAddress, //

    },

    kvec,

    prelude::*,

    scatterlist::{

        Owned,
@@ -16,7 +16,6 @@ 
};



use crate::{

    dma::DmaObject,

    firmware::riscv::RiscvFirmware,

    gpu::{

        Architecture,
@@ -137,7 +136,7 @@ pub(crate) struct GspFirmware { 
    #[pin]

    level1: SGTable<Owned<VVec<u8>>>,

    /// Level 0 page table (single 4KB page) with one entry: DMA address of first level 1 page.

    level0: DmaObject,

    level0: Coherent<[u64]>,

    /// Size in bytes of the firmware contained in [`Self::fw`].

    pub(crate) size: usize,

    /// Device-mapped GSP signatures matching the GPU's [`Chipset`].
@@ -198,17 +197,20 @@ pub(crate) fn new<'a>( 
                    // Allocate the level 0 page table as a device-visible DMA object, and map the

                    // level 1 page table onto it.



                    // Level 0 page table data.

                    let mut level0_data = kvec![0u8; GSP_PAGE_SIZE]?;



                    // Fill level 1 page entry.

                    let level1_entry = level1.iter().next().ok_or(EINVAL)?;

                    let level1_entry_addr = level1_entry.dma_address();

                    let dst = &mut level0_data[..size_of_val(&level1_entry_addr)];

                    dst.copy_from_slice(&level1_entry_addr.to_le_bytes());



                    // Turn the level0 page table into a [`DmaObject`].

                    DmaObject::from_data(dev, &level0_data)?

                    // Create level 0 page table data and fill its first entry with the level 1

                    // table.

                    let mut level0 = CoherentBox::<[u64]>::zeroed_slice(

                        dev,

                        GSP_PAGE_SIZE / size_of::<u64>(),

                        GFP_KERNEL

                    )?;

                    level0[0] = level1_entry_addr.to_le();



                    level0.into()

                },

                size,

                signatures: {

drivers/gpu/nova-core/nova_core.rs

+0 −1
Original line number Diff line number Diff line
@@ -13,7 +13,6 @@ 
#[macro_use]

mod bitfield;



mod dma;

mod driver;

mod falcon;

mod fb;