Commit 15a4bb87 authored by Danilo Krummrich's avatar Danilo Krummrich
Browse files

gpu: nova-core: use sized array for GSP log buffers 



Switch LogBuffer from Coherent<[u8]> (unsized) to
Coherent<[u8; LOG_BUFFER_SIZE]> (sized). The buffer size is a
compile-time constant (RM_LOG_BUFFER_NUM_PAGES * GSP_PAGE_SIZE), so a
fixed-size array is more precise and avoids the need for the runtime
length parameter of zeroed_slice().

Acked-by: default avatarGary Guo <gary@garyguo.net>
Reviewed-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260325003921.3420-3-dakr@kernel.org


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent d1619a43

drivers/gpu/nova-core/gsp.rs

+6 −10
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 


/// Number of GSP pages to use in a RM log buffer.

const RM_LOG_BUFFER_NUM_PAGES: usize = 0x10;

const LOG_BUFFER_SIZE: usize = RM_LOG_BUFFER_NUM_PAGES * GSP_PAGE_SIZE;



/// Array of page table entries, as understood by the GSP bootloader.

#[repr(C)]
@@ -77,24 +78,19 @@ fn entry(start: DmaAddress, index: usize) -> Result<u64> { 
/// then pp points to index into the buffer where the next logging entry will

/// be written. Therefore, the logging data is valid if:

///   1 <= pp < sizeof(buffer)/sizeof(u64)

struct LogBuffer(Coherent<[u8]>);

struct LogBuffer(Coherent<[u8; LOG_BUFFER_SIZE]>);



impl LogBuffer {

    /// Creates a new `LogBuffer` mapped on `dev`.

    fn new(dev: &device::Device<device::Bound>) -> Result<Self> {

        const NUM_PAGES: usize = RM_LOG_BUFFER_NUM_PAGES;



        let obj = Self(Coherent::<u8>::zeroed_slice(

            dev,

            NUM_PAGES * GSP_PAGE_SIZE,

            GFP_KERNEL,

        )?);

        let obj = Self(Coherent::zeroed(dev, GFP_KERNEL)?);



        let start_addr = obj.0.dma_handle();



        // SAFETY: `obj` has just been created and we are its sole user.

        let pte_region =

            unsafe { &mut obj.0.as_mut()[size_of::<u64>()..][..NUM_PAGES * size_of::<u64>()] };

        let pte_region = unsafe {

            &mut obj.0.as_mut()[size_of::<u64>()..][..RM_LOG_BUFFER_NUM_PAGES * size_of::<u64>()]

        };



        // Write values one by one to avoid an on-stack instance of `PteArray`.

        for (i, chunk) in pte_region.chunks_exact_mut(size_of::<u64>()).enumerate() {