[PATCH v2 13/16] gpu: nova-core: convert hshub0 from relative register to projection

[Gary Guo <gary@garyguo.net>]

Similar to the PFALCON and PFALCON2 conversion, the hshub0 relative access
can also be achieved cleanly with projection and a new base.

Signed-off-by: Gary Guo <gary@garyguo.net>
---
 drivers/gpu/nova-core/fb/hal/gb100.rs | 59 +++++++++++++++++------------------
 drivers/gpu/nova-core/fb/regs.rs      | 19 ++++++-----
 2 files changed, 40 insertions(+), 38 deletions(-)

diff --git a/drivers/gpu/nova-core/fb/hal/gb100.rs b/drivers/gpu/nova-core/fb/hal/gb100.rs
index d9e4d62ae632..9fa094939600 100644
--- a/drivers/gpu/nova-core/fb/hal/gb100.rs
+++ b/drivers/gpu/nova-core/fb/hal/gb100.rs
@@ -5,11 +5,10 @@
 
 use kernel::{
     io::{
-        register::{
-            RegisterBase,
-            WithBase, //
-        },
-        Io, //
+        io_project,
+        register,
+        Io,
+        Mmio, //
     },
     num::Bounded,
     prelude::*,
@@ -21,7 +20,10 @@
 };
 
 use crate::{
-    driver::Bar0,
+    driver::{
+        Bar0,
+        NovaRegisters, //
+    },
     fb::{
         hal::FbHal,
         regs, //
@@ -31,17 +33,26 @@
 
 struct Gb100;
 
-impl RegisterBase<regs::Hshub0Base> for Gb100 {
-    const BASE: usize = 0x0087_0000;
+register! {
+    base: NovaRegisters;
+
+    HSHUB0: regs::Hshub0Registers @ 0x0087_0000;
+}
+
+#[inline]
+fn hshub0(bar: Bar0<'_>) -> Mmio<'_, regs::Hshub0Registers> {
+    io_project!(bar, build: HSHUB0)
 }
 
-fn read_sysmem_flush_page_gb100(bar: Bar0<'_>) -> u64 {
+fn read_sysmem_flush_page_gb100(hshub0: Mmio<'_, regs::Hshub0Registers>) -> u64 {
     let lo = u64::from(
-        bar.read(regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_LO::of::<Gb100>())
+        hshub0
+            .read(regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_LO)
             .adr(),
     );
     let hi = u64::from(
-        bar.read(regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_HI::of::<Gb100>())
+        hshub0
+            .read(regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_HI)
             .adr(),
     );
 
@@ -52,7 +63,7 @@ fn read_sysmem_flush_page_gb100(bar: Bar0<'_>) -> u64 {
 ///
 /// Both the primary and EG (egress) register pairs must be programmed to the same address,
 /// as required by hardware.
-fn write_sysmem_flush_page_gb100(bar: Bar0<'_>, addr: Bounded<u64, 52>) {
+fn write_sysmem_flush_page_gb100(hshub0: Mmio<'_, regs::Hshub0Registers>, addr: Bounded<u64, 52>) {
     // CAST: lower 32 bits. Hardware ignores bits 7:0.
     let addr_lo = *addr as u32;
     let addr_hi = addr.shr::<32, 20>().cast::<u32>();
@@ -60,24 +71,12 @@ fn write_sysmem_flush_page_gb100(bar: Bar0<'_>, addr: Bounded<u64, 52>) {
     // Write HI first. The hardware will trigger the flush on the LO write.
 
     // Primary HSHUB pair.
-    bar.write(
-        regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_HI::of::<Gb100>(),
-        regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_HI::zeroed().with_adr(addr_hi),
-    );
-    bar.write(
-        regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_LO::of::<Gb100>(),
-        regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_LO::zeroed().with_adr(addr_lo),
-    );
+    hshub0.write_reg(regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_HI::zeroed().with_adr(addr_hi));
+    hshub0.write_reg(regs::NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_LO::zeroed().with_adr(addr_lo));
 
     // EG (egress) pair -- must match the primary pair.
-    bar.write(
-        regs::NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_HI::of::<Gb100>(),
-        regs::NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_HI::zeroed().with_adr(addr_hi),
-    );
-    bar.write(
-        regs::NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_LO::of::<Gb100>(),
-        regs::NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_LO::zeroed().with_adr(addr_lo),
-    );
+    hshub0.write_reg(regs::NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_HI::zeroed().with_adr(addr_hi));
+    hshub0.write_reg(regs::NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_LO::zeroed().with_adr(addr_lo));
 }
 
 // This PMU reservation size is r570-specific.
@@ -88,13 +87,13 @@ pub(super) const fn pmu_reserved_size_gb100() -> u32 {
 
 impl FbHal for Gb100 {
     fn read_sysmem_flush_page(&self, bar: Bar0<'_>) -> u64 {
-        read_sysmem_flush_page_gb100(bar)
+        read_sysmem_flush_page_gb100(hshub0(bar))
     }
 
     fn write_sysmem_flush_page(&self, bar: Bar0<'_>, addr: u64) -> Result {
         let addr = Bounded::<u64, 52>::try_new(addr).ok_or(EINVAL)?;
 
-        write_sysmem_flush_page_gb100(bar, addr);
+        write_sysmem_flush_page_gb100(hshub0(bar), addr);
 
         Ok(())
     }
diff --git a/drivers/gpu/nova-core/fb/regs.rs b/drivers/gpu/nova-core/fb/regs.rs
index c27582e376e2..584488a3e012 100644
--- a/drivers/gpu/nova-core/fb/regs.rs
+++ b/drivers/gpu/nova-core/fb/regs.rs
@@ -2,7 +2,8 @@
 
 use kernel::{
     io::register,
-    sizes::SizeConstants, //
+    prelude::*,
+    sizes::{SizeConstants, SZ_4K}, //
 };
 
 use crate::driver::NovaRegisters;
@@ -65,31 +66,33 @@ pub(super) fn vga_workspace_addr(self) -> Option<u64> {
     }
 }
 
-/// Base of the GB10x HSHUB0 register window (`NV_HSHUB0_PRIV_BASE` in Open RM).
+/// The GB10x HSHUB0 register window (Base defined as `NV_HSHUB0_PRIV_BASE` in Open RM).
 ///
 /// The base is provided by the GB10x framebuffer HAL.
-pub(super) struct Hshub0Base(());
+#[repr(align(4))]
+#[derive(FromBytes, IntoBytes)]
+pub(super) struct Hshub0Registers([u8; SZ_4K]);
 
 register! {
-    base: NovaRegisters;
+    base: Hshub0Registers;
 
     // GB10x sysmem flush registers, relative to the HSHUB0 base. GB10x routes sysmembar
     // through a primary and an EG (egress) pair that must both be programmed to the same
     // address. Hardware ignores bits 7:0 of each LO register. The boot path uses a fixed
     // HSHUB0 base, so the multiple runtime-discovered HSHUB bases are not needed here.
-    pub(super) NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_LO(u32) @ Hshub0Base + 0x00000e50 {
+    pub(super) NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_LO(u32) @ 0x00000e50 {
         31:0    adr => u32;
     }
 
-    pub(super) NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_HI(u32) @ Hshub0Base + 0x00000e54 {
+    pub(super) NV_PFB_HSHUB_PCIE_FLUSH_SYSMEM_ADDR_HI(u32) @ 0x00000e54 {
         19:0    adr;
     }
 
-    pub(super) NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_LO(u32) @ Hshub0Base + 0x000006c0 {
+    pub(super) NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_LO(u32) @ 0x000006c0 {
         31:0    adr => u32;
     }
 
-    pub(super) NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_HI(u32) @ Hshub0Base + 0x000006c4 {
+    pub(super) NV_PFB_HSHUB_EG_PCIE_FLUSH_SYSMEM_ADDR_HI(u32) @ 0x000006c4 {
         19:0    adr;
     }
 }

-- 
2.54.0