1 files changed, 117 insertions, 6 deletions

diff --git a/drivers/gpu/nova-core/gsp.rs b/drivers/gpu/nova-core/gsp.rs
index 55a1ad90a373..ec053395694b 100644
--- a/drivers/gpu/nova-core/gsp.rs
+++ b/drivers/gpu/nova-core/gsp.rs
@@ -2,7 +2,17 @@
 
 mod boot;
 
-use kernel::prelude::*;
+use kernel::{
+    device,
+    dma::{
+        CoherentAllocation,
+        DmaAddress, //
+    },
+    dma_write,
+    pci,
+    prelude::*,
+    transmute::AsBytes, //
+};
 
 mod fw;
 
@@ -11,17 +21,118 @@ pub(crate) use fw::{
     LibosParams, //
 };
 
+use crate::{
+    gsp::fw::LibosMemoryRegionInitArgument,
+    num, //
+};
+
 pub(crate) const GSP_PAGE_SHIFT: usize = 12;
 pub(crate) const GSP_PAGE_SIZE: usize = 1 << GSP_PAGE_SHIFT;
 
-/// GSP runtime data.
+/// Number of GSP pages to use in a RM log buffer.
+const RM_LOG_BUFFER_NUM_PAGES: usize = 0x10;
+
+/// Array of page table entries, as understood by the GSP bootloader.
+#[repr(C)]
+struct PteArray<const NUM_ENTRIES: usize>([u64; NUM_ENTRIES]);
+
+/// SAFETY: arrays of `u64` implement `AsBytes` and we are but a wrapper around one.
+unsafe impl<const NUM_ENTRIES: usize> AsBytes for PteArray<NUM_ENTRIES> {}
+
+impl<const NUM_PAGES: usize> PteArray<NUM_PAGES> {
+    /// Creates a new page table array mapping `NUM_PAGES` GSP pages starting at address `start`.
+    fn new(start: DmaAddress) -> Result<Self> {
+        let mut ptes = [0u64; NUM_PAGES];
+        for (i, pte) in ptes.iter_mut().enumerate() {
+            *pte = start
+                .checked_add(num::usize_as_u64(i) << GSP_PAGE_SHIFT)
+                .ok_or(EOVERFLOW)?;
+        }
+
+        Ok(Self(ptes))
+    }
+}
+
+/// The logging buffers are byte queues that contain encoded printf-like
+/// messages from GSP-RM.  They need to be decoded by a special application
+/// that can parse the buffers.
+///
+/// The 'loginit' buffer contains logs from early GSP-RM init and
+/// exception dumps.  The 'logrm' buffer contains the subsequent logs. Both are
+/// written to directly by GSP-RM and can be any multiple of GSP_PAGE_SIZE.
 ///
-/// This is an empty pinned placeholder for now.
+/// The physical address map for the log buffer is stored in the buffer
+/// itself, starting with offset 1. Offset 0 contains the "put" pointer (pp).
+/// Initially, pp is equal to 0. If the buffer has valid logging data in it,
+/// 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(CoherentAllocation<u8>);
+
+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 mut obj = Self(CoherentAllocation::<u8>::alloc_coherent(
+            dev,
+            NUM_PAGES * GSP_PAGE_SIZE,
+            GFP_KERNEL | __GFP_ZERO,
+        )?);
+        let ptes = PteArray::<NUM_PAGES>::new(obj.0.dma_handle())?;
+
+        // SAFETY: `obj` has just been created and we are its sole user.
+        unsafe {
+            // Copy the self-mapping PTE at the expected location.
+            obj.0
+                .as_slice_mut(size_of::<u64>(), size_of_val(&ptes))?
+                .copy_from_slice(ptes.as_bytes())
+        };
+
+        Ok(obj)
+    }
+}
+
+/// GSP runtime data.
 #[pin_data]
-pub(crate) struct Gsp {}
+pub(crate) struct Gsp {
+    /// Libos arguments.
+    pub(crate) libos: CoherentAllocation<LibosMemoryRegionInitArgument>,
+    /// Init log buffer.
+    loginit: LogBuffer,
+    /// Interrupts log buffer.
+    logintr: LogBuffer,
+    /// RM log buffer.
+    logrm: LogBuffer,
+}
 
 impl Gsp {
-    pub(crate) fn new() -> impl PinInit<Self> {
-        pin_init!(Self {})
+    // Creates an in-place initializer for a `Gsp` manager for `pdev`.
+    pub(crate) fn new(pdev: &pci::Device<device::Bound>) -> Result<impl PinInit<Self, Error>> {
+        let dev = pdev.as_ref();
+        let libos = CoherentAllocation::<LibosMemoryRegionInitArgument>::alloc_coherent(
+            dev,
+            GSP_PAGE_SIZE / size_of::<LibosMemoryRegionInitArgument>(),
+            GFP_KERNEL | __GFP_ZERO,
+        )?;
+
+        // Initialise the logging structures. The OpenRM equivalents are in:
+        // _kgspInitLibosLoggingStructures (allocates memory for buffers)
+        // kgspSetupLibosInitArgs_IMPL (creates pLibosInitArgs[] array)
+        let loginit = LogBuffer::new(dev)?;
+        dma_write!(libos[0] = LibosMemoryRegionInitArgument::new("LOGINIT", &loginit.0))?;
+
+        let logintr = LogBuffer::new(dev)?;
+        dma_write!(libos[1] = LibosMemoryRegionInitArgument::new("LOGINTR", &logintr.0))?;
+
+        let logrm = LogBuffer::new(dev)?;
+        dma_write!(libos[2] = LibosMemoryRegionInitArgument::new("LOGRM", &logrm.0))?;
+
+        Ok(try_pin_init!(Self {
+            libos,
+            loginit,
+            logintr,
+            logrm,
+        }))
     }
 }