1 files changed, 217 insertions, 0 deletions
diff --git a/drivers/gpu/nova-core/fb.rs b/drivers/gpu/nova-core/fb.rs
new file mode 100644
index 000000000000..3c9cf151786c
--- /dev/null
+++ b/drivers/gpu/nova-core/fb.rs
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use core::ops::Range;
+
+use kernel::{
+    device,
+    prelude::*,
+    ptr::{
+        Alignable,
+        Alignment, //
+    },
+    sizes::*,
+    sync::aref::ARef, //
+};
+
+use crate::{
+    dma::DmaObject,
+    driver::Bar0,
+    firmware::gsp::GspFirmware,
+    gpu::Chipset,
+    gsp,
+    num::{
+        usize_as_u64,
+        FromSafeCast, //
+    },
+    regs,
+};
+
+mod hal;
+
+/// Type holding the sysmem flush memory page, a page of memory to be written into the
+/// `NV_PFB_NISO_FLUSH_SYSMEM_ADDR*` registers and used to maintain memory coherency.
+///
+/// A system memory page is required for `sysmembar`, which is a GPU-initiated hardware
+/// memory-barrier operation that flushes all pending GPU-side memory writes that were done through
+/// PCIE to system memory. It is required for falcons to be reset as the reset operation involves a
+/// reset handshake. When the falcon acknowledges a reset, it writes into system memory. To ensure
+/// this write is visible to the host and prevent driver timeouts, the falcon must perform a
+/// sysmembar operation to flush its writes.
+///
+/// Because of this, the sysmem flush memory page must be registered as early as possible during
+/// driver initialization, and before any falcon is reset.
+///
+/// Users are responsible for manually calling [`Self::unregister`] before dropping this object,
+/// otherwise the GPU might still use it even after it has been freed.
+pub(crate) struct SysmemFlush {
+    /// Chipset we are operating on.
+    chipset: Chipset,
+    device: ARef<device::Device>,
+    /// Keep the page alive as long as we need it.
+    page: DmaObject,
+}
+
+impl SysmemFlush {
+    /// Allocate a memory page and register it as the sysmem flush page.
+    pub(crate) fn register(
+        dev: &device::Device<device::Bound>,
+        bar: &Bar0,
+        chipset: Chipset,
+    ) -> Result<Self> {
+        let page = DmaObject::new(dev, kernel::page::PAGE_SIZE)?;
+
+        hal::fb_hal(chipset).write_sysmem_flush_page(bar, page.dma_handle())?;
+
+        Ok(Self {
+            chipset,
+            device: dev.into(),
+            page,
+        })
+    }
+
+    /// Unregister the managed sysmem flush page.
+    ///
+    /// In order to gracefully tear down the GPU, users must make sure to call this method before
+    /// dropping the object.
+    pub(crate) fn unregister(&self, bar: &Bar0) {
+        let hal = hal::fb_hal(self.chipset);
+
+        if hal.read_sysmem_flush_page(bar) == self.page.dma_handle() {
+            let _ = hal.write_sysmem_flush_page(bar, 0).inspect_err(|e| {
+                dev_warn!(
+                    &self.device,
+                    "failed to unregister sysmem flush page: {:?}",
+                    e
+                )
+            });
+        } else {
+            // Another page has been registered after us for some reason - warn as this is a bug.
+            dev_warn!(
+                &self.device,
+                "attempt to unregister a sysmem flush page that is not active\n"
+            );
+        }
+    }
+}
+
+/// Layout of the GPU framebuffer memory.
+///
+/// Contains ranges of GPU memory reserved for a given purpose during the GSP boot process.
+#[derive(Debug)]
+pub(crate) struct FbLayout {
+    /// Range of the framebuffer. Starts at `0`.
+    pub(crate) fb: Range<u64>,
+    /// VGA workspace, small area of reserved memory at the end of the framebuffer.
+    pub(crate) vga_workspace: Range<u64>,
+    /// FRTS range.
+    pub(crate) frts: Range<u64>,
+    /// Memory area containing the GSP bootloader image.
+    pub(crate) boot: Range<u64>,
+    /// Memory area containing the GSP firmware image.
+    pub(crate) elf: Range<u64>,
+    /// WPR2 heap.
+    pub(crate) wpr2_heap: Range<u64>,
+    /// WPR2 region range, starting with an instance of `GspFwWprMeta`.
+    pub(crate) wpr2: Range<u64>,
+    pub(crate) heap: Range<u64>,
+    pub(crate) vf_partition_count: u8,
+}
+
+impl FbLayout {
+    /// Computes the FB layout for `chipset` required to run the `gsp_fw` GSP firmware.
+    pub(crate) fn new(chipset: Chipset, bar: &Bar0, gsp_fw: &GspFirmware) -> Result<Self> {
+        let hal = hal::fb_hal(chipset);
+
+        let fb = {
+            let fb_size = hal.vidmem_size(bar);
+
+            0..fb_size
+        };
+
+        let vga_workspace = {
+            let vga_base = {
+                const NV_PRAMIN_SIZE: u64 = usize_as_u64(SZ_1M);
+                let base = fb.end - NV_PRAMIN_SIZE;
+
+                if hal.supports_display(bar) {
+                    match regs::NV_PDISP_VGA_WORKSPACE_BASE::read(bar).vga_workspace_addr() {
+                        Some(addr) => {
+                            if addr < base {
+                                const VBIOS_WORKSPACE_SIZE: u64 = usize_as_u64(SZ_128K);
+
+                                // Point workspace address to end of framebuffer.
+                                fb.end - VBIOS_WORKSPACE_SIZE
+                            } else {
+                                addr
+                            }
+                        }
+                        None => base,
+                    }
+                } else {
+                    base
+                }
+            };
+
+            vga_base..fb.end
+        };
+
+        let frts = {
+            const FRTS_DOWN_ALIGN: Alignment = Alignment::new::<SZ_128K>();
+            const FRTS_SIZE: u64 = usize_as_u64(SZ_1M);
+            let frts_base = vga_workspace.start.align_down(FRTS_DOWN_ALIGN) - FRTS_SIZE;
+
+            frts_base..frts_base + FRTS_SIZE
+        };
+
+        let boot = {
+            const BOOTLOADER_DOWN_ALIGN: Alignment = Alignment::new::<SZ_4K>();
+            let bootloader_size = u64::from_safe_cast(gsp_fw.bootloader.ucode.size());
+            let bootloader_base = (frts.start - bootloader_size).align_down(BOOTLOADER_DOWN_ALIGN);
+
+            bootloader_base..bootloader_base + bootloader_size
+        };
+
+        let elf = {
+            const ELF_DOWN_ALIGN: Alignment = Alignment::new::<SZ_64K>();
+            let elf_size = u64::from_safe_cast(gsp_fw.size);
+            let elf_addr = (boot.start - elf_size).align_down(ELF_DOWN_ALIGN);
+
+            elf_addr..elf_addr + elf_size
+        };
+
+        let wpr2_heap = {
+            const WPR2_HEAP_DOWN_ALIGN: Alignment = Alignment::new::<SZ_1M>();
+            let wpr2_heap_size =
+                gsp::LibosParams::from_chipset(chipset).wpr_heap_size(chipset, fb.end);
+            let wpr2_heap_addr = (elf.start - wpr2_heap_size).align_down(WPR2_HEAP_DOWN_ALIGN);
+
+            wpr2_heap_addr..(elf.start).align_down(WPR2_HEAP_DOWN_ALIGN)
+        };
+
+        let wpr2 = {
+            const WPR2_DOWN_ALIGN: Alignment = Alignment::new::<SZ_1M>();
+            let wpr2_addr = (wpr2_heap.start - u64::from_safe_cast(size_of::<gsp::GspFwWprMeta>()))
+                .align_down(WPR2_DOWN_ALIGN);
+
+            wpr2_addr..frts.end
+        };
+
+        let heap = {
+            const HEAP_SIZE: u64 = usize_as_u64(SZ_1M);
+
+            wpr2.start - HEAP_SIZE..wpr2.start
+        };
+
+        Ok(Self {
+            fb,
+            vga_workspace,
+            frts,
+            boot,
+            elf,
+            wpr2_heap,
+            wpr2,
+            heap,
+            vf_partition_count: 0,
+        })
+    }
+}