gpu: nova-core: gsp: Add SetRegistry command

Add support for sending the SetRegistry command, which is critical to
GSP initialization.

The RM registry is serialized into a packed format and sent via the
command queue. For now only three parameters which are required to boot
GSP are hardcoded. In the future a kernel module parameter will be added
to enable other parameters to be added.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
[acourbot@nvidia.com: split into its own patch.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251110-gsp_boot-v9-12-8ae4058e3c0e@nvidia.com>

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

@@ -158,6 +158,7 @@ impl super::Gsp {
 
         self.cmdq
             .send_command(bar, commands::SetSystemInfo::new(pdev))?;
+        self.cmdq.send_command(bar, commands::SetRegistry::new())?;
 
         Ok(())
     }

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

@@ -1,17 +1,23 @@
 // SPDX-License-Identifier: GPL-2.0
 
+use core::convert::Infallible;
+
 use kernel::{
     device,
     pci,
-    prelude::*, //
+    prelude::*,
+    transmute::AsBytes, //
 };
 
-use crate::gsp::{
-    cmdq::CommandToGsp,
-    fw::{
-        commands::GspSetSystemInfo,
-        MsgFunction, //
+use crate::{
+    gsp::{
+        cmdq::CommandToGsp,
+        fw::{
+            commands::*,
+            MsgFunction, //
+        },
     },
+    sbuffer::SBufferIter,
 };
 
 /// The `GspSetSystemInfo` command.
@@ -35,3 +41,89 @@ impl<'a> CommandToGsp for SetSystemInfo<'a> {
         GspSetSystemInfo::init(self.pdev)
     }
 }
+
+struct RegistryEntry {
+    key: &'static str,
+    value: u32,
+}
+
+/// The `SetRegistry` command.
+pub(crate) struct SetRegistry {
+    entries: [RegistryEntry; Self::NUM_ENTRIES],
+}
+
+impl SetRegistry {
+    // For now we hard-code the registry entries. Future work will allow others to
+    // be added as module parameters.
+    const NUM_ENTRIES: usize = 3;
+
+    /// Creates a new `SetRegistry` command, using a set of hardcoded entries.
+    pub(crate) fn new() -> Self {
+        Self {
+            entries: [
+                // RMSecBusResetEnable - enables PCI secondary bus reset
+                RegistryEntry {
+                    key: "RMSecBusResetEnable",
+                    value: 1,
+                },
+                // RMForcePcieConfigSave - forces GSP-RM to preserve PCI configuration registers on
+                // any PCI reset.
+                RegistryEntry {
+                    key: "RMForcePcieConfigSave",
+                    value: 1,
+                },
+                // RMDevidCheckIgnore - allows GSP-RM to boot even if the PCI dev ID is not found
+                // in the internal product name database.
+                RegistryEntry {
+                    key: "RMDevidCheckIgnore",
+                    value: 1,
+                },
+            ],
+        }
+    }
+}
+
+impl CommandToGsp for SetRegistry {
+    const FUNCTION: MsgFunction = MsgFunction::SetRegistry;
+    type Command = PackedRegistryTable;
+    type InitError = Infallible;
+
+    fn init(&self) -> impl Init<Self::Command, Self::InitError> {
+        PackedRegistryTable::init(Self::NUM_ENTRIES as u32, self.variable_payload_len() as u32)
+    }
+
+    fn variable_payload_len(&self) -> usize {
+        let mut key_size = 0;
+        for i in 0..Self::NUM_ENTRIES {
+            key_size += self.entries[i].key.len() + 1; // +1 for NULL terminator
+        }
+        Self::NUM_ENTRIES * size_of::<PackedRegistryEntry>() + key_size
+    }
+
+    fn init_variable_payload(
+        &self,
+        dst: &mut SBufferIter<core::array::IntoIter<&mut [u8], 2>>,
+    ) -> Result {
+        let string_data_start_offset =
+            size_of::<PackedRegistryTable>() + Self::NUM_ENTRIES * size_of::<PackedRegistryEntry>();
+
+        // Array for string data.
+        let mut string_data = KVec::new();
+
+        for entry in self.entries.iter().take(Self::NUM_ENTRIES) {
+            dst.write_all(
+                PackedRegistryEntry::new(
+                    (string_data_start_offset + string_data.len()) as u32,
+                    entry.value,
+                )
+                .as_bytes(),
+            )?;
+
+            let key_bytes = entry.key.as_bytes();
+            string_data.extend_from_slice(key_bytes, GFP_KERNEL)?;
+            string_data.push(0, GFP_KERNEL)?;
+        }
+
+        dst.write_all(string_data.as_slice())
+    }
+}

drivers/gpu/nova-core/gsp/fw/commands.rs

@@ -54,3 +54,53 @@ unsafe impl AsBytes for GspSetSystemInfo {}
 // SAFETY: These structs don't meet the no-padding requirements of FromBytes but
 //         that is not a problem because they are not used outside the kernel.
 unsafe impl FromBytes for GspSetSystemInfo {}
+
+#[repr(transparent)]
+pub(crate) struct PackedRegistryEntry(bindings::PACKED_REGISTRY_ENTRY);
+
+impl PackedRegistryEntry {
+    pub(crate) fn new(offset: u32, value: u32) -> Self {
+        Self({
+            bindings::PACKED_REGISTRY_ENTRY {
+                nameOffset: offset,
+
+                // We only support DWORD types for now. Support for other types
+                // will come later if required.
+                type_: bindings::REGISTRY_TABLE_ENTRY_TYPE_DWORD as u8,
+                __bindgen_padding_0: Default::default(),
+                data: value,
+                length: 0,
+            }
+        })
+    }
+}
+
+// SAFETY: Padding is explicit and will not contain uninitialized data.
+unsafe impl AsBytes for PackedRegistryEntry {}
+
+/// Payload of the `SetRegistry` command.
+#[repr(transparent)]
+pub(crate) struct PackedRegistryTable {
+    inner: bindings::PACKED_REGISTRY_TABLE,
+}
+
+impl PackedRegistryTable {
+    #[allow(non_snake_case)]
+    pub(crate) fn init(num_entries: u32, size: u32) -> impl Init<Self> {
+        type InnerPackedRegistryTable = bindings::PACKED_REGISTRY_TABLE;
+        let init_inner = init!(InnerPackedRegistryTable {
+            numEntries: num_entries,
+            size,
+            entries: Default::default()
+        });
+
+        init!(PackedRegistryTable { inner <- init_inner })
+    }
+}
+
+// SAFETY: Padding is explicit and will not contain uninitialized data.
+unsafe impl AsBytes for PackedRegistryTable {}
+
+// SAFETY: This struct only contains integer types for which all bit patterns
+// are valid.
+unsafe impl FromBytes for PackedRegistryTable {}

drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs

@@ -649,6 +649,22 @@ pub struct LibosMemoryRegionInitArgument {
     pub __bindgen_padding_0: [u8; 6usize],
 }
 #[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct PACKED_REGISTRY_ENTRY {
+    pub nameOffset: u32_,
+    pub type_: u8_,
+    pub __bindgen_padding_0: [u8; 3usize],
+    pub data: u32_,
+    pub length: u32_,
+}
+#[repr(C)]
+#[derive(Debug, Default)]
+pub struct PACKED_REGISTRY_TABLE {
+    pub size: u32_,
+    pub numEntries: u32_,
+    pub entries: __IncompleteArrayField<PACKED_REGISTRY_ENTRY>,
+}
+#[repr(C)]
 #[derive(Debug, Default, Copy, Clone, Zeroable)]
 pub struct msgqTxHeader {
     pub version: u32_,

drivers/gpu/nova-core/sbuffer.rs

@@ -199,7 +199,6 @@ where
 
     /// Ideally we would implement [`Write`], but it is not available in `core`.
     /// So mimic `std::io::Write::write_all`.
-    #[expect(unused)]
     pub(crate) fn write_all(&mut self, mut src: &[u8]) -> Result {
         while !src.is_empty() {
             match self.get_slice_mut(src.len()) {