[PATCH v3 0/8] gpu: nova-core: miscellaneous improvements

[PATCH v3 0/8] gpu: nova-core: miscellaneous improvements

[Alexandre Courbot]

A few simple, loosely-related small improvements for nova-core,
including reporting unprocessed data in GSP messages, removal of
unnecessary code in GSP and the sequencer, and leveraging the Zeroable
derive macro and core library's CStr. Probably nothing too
controversial, so I plan on applying it soon after -rc1 gets released.

This revision is based on master.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
Changes in v3:
- Use inspect() to warn about remaining data in the GSP command queue.
- Drop "firmware: fwsec: do not require bound device when unneeded".
- Drop "simplify str_from_null_terminated" as `str_from_null_terminated`
  has been removed.
- Derive `Zeroable` on the original `GspStaticConfigInfo` tuple struct.
- Link to v2: https://patch.msgid.link/20251216-nova-misc-v2-0-dc7b42586c04@nvidia.com

Changes in v2:
- Rebase on drm-rust-next.
- Add a patch to reuse previously acquired reference to define in GSP
  boot sequence.
- Link to v1: https://patch.msgid.link/20251208-nova-misc-v1-0-a3ce01376169@nvidia.com

---
Alexandre Courbot (8):
      gpu: nova-core: gsp: warn if data remains after processing a message
      gpu: nova-core: gsp: remove unnecessary Display impls
      gpu: nova-core: gsp: simplify sequencer opcode parsing
      gpu: nova-core: gsp: remove unneeded sequencer trait
      gpu: nova-core: gsp: derive `Debug` on more sequencer types
      gpu: nova-core: gsp: derive Zeroable for GspStaticConfigInfo
      gpu: nova-core: use core library's CStr instead of kernel one
      gpu: nova-core: gsp: use available device reference

 drivers/gpu/nova-core/firmware.rs        |   2 +-
 drivers/gpu/nova-core/firmware/gsp.rs    |   6 +-
 drivers/gpu/nova-core/gsp/boot.rs        |  34 +++-------
 drivers/gpu/nova-core/gsp/cmdq.rs        |  14 ++++-
 drivers/gpu/nova-core/gsp/fw.rs          | 104 +++----------------------------
 drivers/gpu/nova-core/gsp/fw/commands.rs |   5 +-
 drivers/gpu/nova-core/gsp/sequencer.rs   |  18 +++---
 drivers/gpu/nova-core/nova_core.rs       |   2 +-
 8 files changed, 45 insertions(+), 140 deletions(-)
---
base-commit: 9702969978695d9a699a1f34771580cdbb153b33
change-id: 20251208-nova-misc-1d797b5d64f2

Best regards,
-- 
Alexandre Courbot <acourbot@nvidia.com>

[PATCH v3 1/8] gpu: nova-core: gsp: warn if data remains after processing a message

[Alexandre Courbot]

Not processing the whole data from a received message is a strong
indicator of a bug - emit a warning when such cases are detected.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/gsp/cmdq.rs | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 46819a82a51a..607fb9ad69b0 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -661,7 +661,17 @@ pub(crate) fn receive_msg<M: MessageFromGsp>(&mut self, timeout: Delta) -> Resul
             let (cmd, contents_1) = M::Message::from_bytes_prefix(message.contents.0).ok_or(EIO)?;
             let mut sbuffer = SBufferIter::new_reader([contents_1, message.contents.1]);
 
-            M::read(cmd, &mut sbuffer).map_err(|e| e.into())
+            M::read(cmd, &mut sbuffer)
+                .map_err(|e| e.into())
+                .inspect(|_| {
+                    if !sbuffer.is_empty() {
+                        dev_warn!(
+                            &self.dev,
+                            "GSP message {:?} has unprocessed data\n",
+                            function
+                        );
+                    }
+                })
         } else {
             Err(ERANGE)
         };

-- 
2.53.0

[PATCH v3 2/8] gpu: nova-core: gsp: remove unnecessary Display impls

[Alexandre Courbot]

We only ever display these in debug context, for which the automatically
derived `Debug` impls work just fine - so use them and remove these
boilerplate-looking implementations.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/gsp/cmdq.rs |  2 +-
 drivers/gpu/nova-core/gsp/fw.rs   | 54 ---------------------------------------
 2 files changed, 1 insertion(+), 55 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 607fb9ad69b0..9eabec49849d 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -531,7 +531,7 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
 
         dev_dbg!(
             &self.dev,
-            "GSP RPC: send: seq# {}, function={}, length=0x{:x}\n",
+            "GSP RPC: send: seq# {}, function={:?}, length=0x{:x}\n",
             self.seq,
             M::FUNCTION,
             dst.header.length(),
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 83ff91614e36..3c26b165038e 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -10,7 +10,6 @@
 
 use kernel::{
     dma::CoherentAllocation,
-    fmt,
     prelude::*,
     ptr::{
         Alignable,
@@ -223,43 +222,6 @@ pub(crate) enum MsgFunction {
     UcodeLibOsPrint = bindings::NV_VGPU_MSG_EVENT_UCODE_LIBOS_PRINT,
 }
 
-impl fmt::Display for MsgFunction {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            // Common function codes
-            MsgFunction::Nop => write!(f, "NOP"),
-            MsgFunction::SetGuestSystemInfo => write!(f, "SET_GUEST_SYSTEM_INFO"),
-            MsgFunction::AllocRoot => write!(f, "ALLOC_ROOT"),
-            MsgFunction::AllocDevice => write!(f, "ALLOC_DEVICE"),
-            MsgFunction::AllocMemory => write!(f, "ALLOC_MEMORY"),
-            MsgFunction::AllocCtxDma => write!(f, "ALLOC_CTX_DMA"),
-            MsgFunction::AllocChannelDma => write!(f, "ALLOC_CHANNEL_DMA"),
-            MsgFunction::MapMemory => write!(f, "MAP_MEMORY"),
-            MsgFunction::BindCtxDma => write!(f, "BIND_CTX_DMA"),
-            MsgFunction::AllocObject => write!(f, "ALLOC_OBJECT"),
-            MsgFunction::Free => write!(f, "FREE"),
-            MsgFunction::Log => write!(f, "LOG"),
-            MsgFunction::GetGspStaticInfo => write!(f, "GET_GSP_STATIC_INFO"),
-            MsgFunction::SetRegistry => write!(f, "SET_REGISTRY"),
-            MsgFunction::GspSetSystemInfo => write!(f, "GSP_SET_SYSTEM_INFO"),
-            MsgFunction::GspInitPostObjGpu => write!(f, "GSP_INIT_POST_OBJGPU"),
-            MsgFunction::GspRmControl => write!(f, "GSP_RM_CONTROL"),
-            MsgFunction::GetStaticInfo => write!(f, "GET_STATIC_INFO"),
-
-            // Event codes
-            MsgFunction::GspInitDone => write!(f, "INIT_DONE"),
-            MsgFunction::GspRunCpuSequencer => write!(f, "RUN_CPU_SEQUENCER"),
-            MsgFunction::PostEvent => write!(f, "POST_EVENT"),
-            MsgFunction::RcTriggered => write!(f, "RC_TRIGGERED"),
-            MsgFunction::MmuFaultQueued => write!(f, "MMU_FAULT_QUEUED"),
-            MsgFunction::OsErrorLog => write!(f, "OS_ERROR_LOG"),
-            MsgFunction::GspPostNoCat => write!(f, "NOCAT"),
-            MsgFunction::GspLockdownNotice => write!(f, "LOCKDOWN_NOTICE"),
-            MsgFunction::UcodeLibOsPrint => write!(f, "LIBOS_PRINT"),
-        }
-    }
-}
-
 impl TryFrom<u32> for MsgFunction {
     type Error = kernel::error::Error;
 
@@ -330,22 +292,6 @@ pub(crate) enum SeqBufOpcode {
     RegWrite = bindings::GSP_SEQ_BUF_OPCODE_GSP_SEQ_BUF_OPCODE_REG_WRITE,
 }
 
-impl fmt::Display for SeqBufOpcode {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            SeqBufOpcode::CoreReset => write!(f, "CORE_RESET"),
-            SeqBufOpcode::CoreResume => write!(f, "CORE_RESUME"),
-            SeqBufOpcode::CoreStart => write!(f, "CORE_START"),
-            SeqBufOpcode::CoreWaitForHalt => write!(f, "CORE_WAIT_FOR_HALT"),
-            SeqBufOpcode::DelayUs => write!(f, "DELAY_US"),
-            SeqBufOpcode::RegModify => write!(f, "REG_MODIFY"),
-            SeqBufOpcode::RegPoll => write!(f, "REG_POLL"),
-            SeqBufOpcode::RegStore => write!(f, "REG_STORE"),
-            SeqBufOpcode::RegWrite => write!(f, "REG_WRITE"),
-        }
-    }
-}
-
 impl TryFrom<u32> for SeqBufOpcode {
     type Error = kernel::error::Error;
 

-- 
2.53.0

[PATCH v3 3/8] gpu: nova-core: gsp: simplify sequencer opcode parsing

[Alexandre Courbot]

The opcodes are already the right type in the C union, so we can use
them directly instead of converting them to a byte stream and back again
using `FromBytes`.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/gsp/fw.rs | 40 +++++-----------------------------------
 1 file changed, 5 insertions(+), 35 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 3c26b165038e..624f5670ed50 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -472,13 +472,7 @@ pub(crate) fn reg_write_payload(&self) -> Result<RegWritePayload> {
             return Err(EINVAL);
         }
         // SAFETY: Opcode is verified to be `RegWrite`, so union contains valid `RegWritePayload`.
-        let payload_bytes = unsafe {
-            core::slice::from_raw_parts(
-                core::ptr::addr_of!(self.0.payload.regWrite).cast::<u8>(),
-                core::mem::size_of::<RegWritePayload>(),
-            )
-        };
-        Ok(*RegWritePayload::from_bytes(payload_bytes).ok_or(EINVAL)?)
+        Ok(RegWritePayload(unsafe { self.0.payload.regWrite }))
     }
 
     /// Returns the register modify payload by value.
@@ -489,13 +483,7 @@ pub(crate) fn reg_modify_payload(&self) -> Result<RegModifyPayload> {
             return Err(EINVAL);
         }
         // SAFETY: Opcode is verified to be `RegModify`, so union contains valid `RegModifyPayload`.
-        let payload_bytes = unsafe {
-            core::slice::from_raw_parts(
-                core::ptr::addr_of!(self.0.payload.regModify).cast::<u8>(),
-                core::mem::size_of::<RegModifyPayload>(),
-            )
-        };
-        Ok(*RegModifyPayload::from_bytes(payload_bytes).ok_or(EINVAL)?)
+        Ok(RegModifyPayload(unsafe { self.0.payload.regModify }))
     }
 
     /// Returns the register poll payload by value.
@@ -506,13 +494,7 @@ pub(crate) fn reg_poll_payload(&self) -> Result<RegPollPayload> {
             return Err(EINVAL);
         }
         // SAFETY: Opcode is verified to be `RegPoll`, so union contains valid `RegPollPayload`.
-        let payload_bytes = unsafe {
-            core::slice::from_raw_parts(
-                core::ptr::addr_of!(self.0.payload.regPoll).cast::<u8>(),
-                core::mem::size_of::<RegPollPayload>(),
-            )
-        };
-        Ok(*RegPollPayload::from_bytes(payload_bytes).ok_or(EINVAL)?)
+        Ok(RegPollPayload(unsafe { self.0.payload.regPoll }))
     }
 
     /// Returns the delay payload by value.
@@ -523,13 +505,7 @@ pub(crate) fn delay_us_payload(&self) -> Result<DelayUsPayload> {
             return Err(EINVAL);
         }
         // SAFETY: Opcode is verified to be `DelayUs`, so union contains valid `DelayUsPayload`.
-        let payload_bytes = unsafe {
-            core::slice::from_raw_parts(
-                core::ptr::addr_of!(self.0.payload.delayUs).cast::<u8>(),
-                core::mem::size_of::<DelayUsPayload>(),
-            )
-        };
-        Ok(*DelayUsPayload::from_bytes(payload_bytes).ok_or(EINVAL)?)
+        Ok(DelayUsPayload(unsafe { self.0.payload.delayUs }))
     }
 
     /// Returns the register store payload by value.
@@ -540,13 +516,7 @@ pub(crate) fn reg_store_payload(&self) -> Result<RegStorePayload> {
             return Err(EINVAL);
         }
         // SAFETY: Opcode is verified to be `RegStore`, so union contains valid `RegStorePayload`.
-        let payload_bytes = unsafe {
-            core::slice::from_raw_parts(
-                core::ptr::addr_of!(self.0.payload.regStore).cast::<u8>(),
-                core::mem::size_of::<RegStorePayload>(),
-            )
-        };
-        Ok(*RegStorePayload::from_bytes(payload_bytes).ok_or(EINVAL)?)
+        Ok(RegStorePayload(unsafe { self.0.payload.regStore }))
     }
 }
 

-- 
2.53.0

[PATCH v3 4/8] gpu: nova-core: gsp: remove unneeded sequencer trait

[Alexandre Courbot]

The `GspSeqCmdRunner` trait is never used as we never call the `run`
methods from generic code. Remove it.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/gsp/sequencer.rs | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/sequencer.rs b/drivers/gpu/nova-core/gsp/sequencer.rs
index e415a2aa3203..9278ffd5216d 100644
--- a/drivers/gpu/nova-core/gsp/sequencer.rs
+++ b/drivers/gpu/nova-core/gsp/sequencer.rs
@@ -144,12 +144,7 @@ pub(crate) struct GspSequencer<'a> {
     dev: ARef<device::Device>,
 }
 
-/// Trait for running sequencer commands.
-pub(crate) trait GspSeqCmdRunner {
-    fn run(&self, sequencer: &GspSequencer<'_>) -> Result;
-}
-
-impl GspSeqCmdRunner for fw::RegWritePayload {
+impl fw::RegWritePayload {
     fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
         let addr = usize::from_safe_cast(self.addr());
 
@@ -157,7 +152,7 @@ fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
     }
 }
 
-impl GspSeqCmdRunner for fw::RegModifyPayload {
+impl fw::RegModifyPayload {
     fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
         let addr = usize::from_safe_cast(self.addr());
 
@@ -169,7 +164,7 @@ fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
     }
 }
 
-impl GspSeqCmdRunner for fw::RegPollPayload {
+impl fw::RegPollPayload {
     fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
         let addr = usize::from_safe_cast(self.addr());
 
@@ -194,14 +189,14 @@ fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
     }
 }
 
-impl GspSeqCmdRunner for fw::DelayUsPayload {
+impl fw::DelayUsPayload {
     fn run(&self, _sequencer: &GspSequencer<'_>) -> Result {
         fsleep(Delta::from_micros(i64::from(self.val())));
         Ok(())
     }
 }
 
-impl GspSeqCmdRunner for fw::RegStorePayload {
+impl fw::RegStorePayload {
     fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
         let addr = usize::from_safe_cast(self.addr());
 
@@ -209,7 +204,7 @@ fn run(&self, sequencer: &GspSequencer<'_>) -> Result {
     }
 }
 
-impl GspSeqCmdRunner for GspSeqCmd {
+impl GspSeqCmd {
     fn run(&self, seq: &GspSequencer<'_>) -> Result {
         match self {
             GspSeqCmd::RegWrite(cmd) => cmd.run(seq),

-- 
2.53.0

[PATCH v3 5/8] gpu: nova-core: gsp: derive `Debug` on more sequencer types

[Alexandre Courbot]

Being able to print these is useful when debugging the sequencer.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/gsp/fw.rs        | 10 +++++-----
 drivers/gpu/nova-core/gsp/sequencer.rs |  1 +
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 624f5670ed50..f1797e1f0d9d 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -330,7 +330,7 @@ fn from(value: SeqBufOpcode) -> Self {
 
 /// Wrapper for GSP sequencer register write payload.
 #[repr(transparent)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub(crate) struct RegWritePayload(bindings::GSP_SEQ_BUF_PAYLOAD_REG_WRITE);
 
 impl RegWritePayload {
@@ -353,7 +353,7 @@ unsafe impl AsBytes for RegWritePayload {}
 
 /// Wrapper for GSP sequencer register modify payload.
 #[repr(transparent)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub(crate) struct RegModifyPayload(bindings::GSP_SEQ_BUF_PAYLOAD_REG_MODIFY);
 
 impl RegModifyPayload {
@@ -381,7 +381,7 @@ unsafe impl AsBytes for RegModifyPayload {}
 
 /// Wrapper for GSP sequencer register poll payload.
 #[repr(transparent)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub(crate) struct RegPollPayload(bindings::GSP_SEQ_BUF_PAYLOAD_REG_POLL);
 
 impl RegPollPayload {
@@ -414,7 +414,7 @@ unsafe impl AsBytes for RegPollPayload {}
 
 /// Wrapper for GSP sequencer delay payload.
 #[repr(transparent)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub(crate) struct DelayUsPayload(bindings::GSP_SEQ_BUF_PAYLOAD_DELAY_US);
 
 impl DelayUsPayload {
@@ -432,7 +432,7 @@ unsafe impl AsBytes for DelayUsPayload {}
 
 /// Wrapper for GSP sequencer register store payload.
 #[repr(transparent)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub(crate) struct RegStorePayload(bindings::GSP_SEQ_BUF_PAYLOAD_REG_STORE);
 
 impl RegStorePayload {
diff --git a/drivers/gpu/nova-core/gsp/sequencer.rs b/drivers/gpu/nova-core/gsp/sequencer.rs
index 9278ffd5216d..0cfbedc47fcf 100644
--- a/drivers/gpu/nova-core/gsp/sequencer.rs
+++ b/drivers/gpu/nova-core/gsp/sequencer.rs
@@ -67,6 +67,7 @@ fn read(
 /// GSP Sequencer Command types with payload data.
 /// Commands have an opcode and an opcode-dependent struct.
 #[allow(clippy::enum_variant_names)]
+#[derive(Debug)]
 pub(crate) enum GspSeqCmd {
     RegWrite(fw::RegWritePayload),
     RegModify(fw::RegModifyPayload),

-- 
2.53.0

[PATCH v3 6/8] gpu: nova-core: gsp: derive Zeroable for GspStaticConfigInfo

[Alexandre Courbot]

We can now derive `Zeroable` on tuple structs, so do this instead of
providing our own implementation.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/gsp/fw/commands.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/fw/commands.rs b/drivers/gpu/nova-core/gsp/fw/commands.rs
index 21be44199693..67f44421fcc3 100644
--- a/drivers/gpu/nova-core/gsp/fw/commands.rs
+++ b/drivers/gpu/nova-core/gsp/fw/commands.rs
@@ -107,6 +107,7 @@ unsafe impl FromBytes for PackedRegistryTable {}
 
 /// Payload of the `GetGspStaticInfo` command and message.
 #[repr(transparent)]
+#[derive(Zeroable)]
 pub(crate) struct GspStaticConfigInfo(bindings::GspStaticConfigInfo_t);
 
 impl GspStaticConfigInfo {
@@ -122,7 +123,3 @@ unsafe impl AsBytes for GspStaticConfigInfo {}
 // SAFETY: This struct only contains integer types for which all bit patterns
 // are valid.
 unsafe impl FromBytes for GspStaticConfigInfo {}
-
-// SAFETY: This struct only contains integer types and fixed-size arrays for which
-// all bit patterns are valid.
-unsafe impl Zeroable for GspStaticConfigInfo {}

-- 
2.53.0

[PATCH v3 7/8] gpu: nova-core: use core library's CStr instead of kernel one

[Alexandre Courbot]

The kernel's own CStr type has been replaced by the one in the core
library, and is now an alias to the latter. Change our imports to
directly reference the actual type.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/firmware.rs     | 2 +-
 drivers/gpu/nova-core/firmware/gsp.rs | 6 +++++-
 drivers/gpu/nova-core/nova_core.rs    | 2 +-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
index 68779540aa28..2f7249383e51 100644
--- a/drivers/gpu/nova-core/firmware.rs
+++ b/drivers/gpu/nova-core/firmware.rs
@@ -424,7 +424,7 @@ const fn make_entry_chipset(self, chipset: &str) -> Self {
     }
 
     pub(crate) const fn create(
-        module_name: &'static kernel::str::CStr,
+        module_name: &'static core::ffi::CStr,
     ) -> firmware::ModInfoBuilder<N> {
         let mut this = Self(firmware::ModInfoBuilder::new(module_name));
         let mut i = 0;
diff --git a/drivers/gpu/nova-core/firmware/gsp.rs b/drivers/gpu/nova-core/firmware/gsp.rs
index 9488a626352f..ae3f6581c5b6 100644
--- a/drivers/gpu/nova-core/firmware/gsp.rs
+++ b/drivers/gpu/nova-core/firmware/gsp.rs
@@ -32,9 +32,13 @@
 /// that scheme before nova-core becomes stable, which means this module will eventually be
 /// removed.
 mod elf {
+    use core::{
+        ffi::CStr,
+        mem::size_of, //
+    };
+
     use kernel::{
         bindings,
-        prelude::*,
         transmute::FromBytes, //
     };
 
diff --git a/drivers/gpu/nova-core/nova_core.rs b/drivers/gpu/nova-core/nova_core.rs
index c1121e7c64c5..b5caf1044697 100644
--- a/drivers/gpu/nova-core/nova_core.rs
+++ b/drivers/gpu/nova-core/nova_core.rs
@@ -18,7 +18,7 @@
 mod sbuffer;
 mod vbios;
 
-pub(crate) const MODULE_NAME: &kernel::str::CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
+pub(crate) const MODULE_NAME: &core::ffi::CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
 
 kernel::module_pci_driver! {
     type: driver::NovaCore,

-- 
2.53.0

Re: [PATCH v3 7/8] gpu: nova-core: use core library's CStr instead of kernel one

[Danilo Krummrich]

On Tue Feb 17, 2026 at 3:45 AM CET, Alexandre Courbot wrote:
> The kernel's own CStr type has been replaced by the one in the core
> library, and is now an alias to the latter. Change our imports to
> directly reference the actual type.
>
> Reviewed-by: Lyude Paul <lyude@redhat.com>
> Reviewed-by: Gary Guo <gary@garyguo.net>
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
>  drivers/gpu/nova-core/firmware.rs     | 2 +-
>  drivers/gpu/nova-core/firmware/gsp.rs | 6 +++++-
>  drivers/gpu/nova-core/nova_core.rs    | 2 +-
>  3 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
> index 68779540aa28..2f7249383e51 100644
> --- a/drivers/gpu/nova-core/firmware.rs
> +++ b/drivers/gpu/nova-core/firmware.rs
> @@ -424,7 +424,7 @@ const fn make_entry_chipset(self, chipset: &str) -> Self {
>      }
>  
>      pub(crate) const fn create(
> -        module_name: &'static kernel::str::CStr,
> +        module_name: &'static core::ffi::CStr,
>      ) -> firmware::ModInfoBuilder<N> {
>          let mut this = Self(firmware::ModInfoBuilder::new(module_name));
>          let mut i = 0;
> diff --git a/drivers/gpu/nova-core/firmware/gsp.rs b/drivers/gpu/nova-core/firmware/gsp.rs
> index 9488a626352f..ae3f6581c5b6 100644
> --- a/drivers/gpu/nova-core/firmware/gsp.rs
> +++ b/drivers/gpu/nova-core/firmware/gsp.rs
> @@ -32,9 +32,13 @@
>  /// that scheme before nova-core becomes stable, which means this module will eventually be
>  /// removed.
>  mod elf {
> +    use core::{
> +        ffi::CStr,
> +        mem::size_of, //
> +    };
> +
>      use kernel::{
>          bindings,
> -        prelude::*,
>          transmute::FromBytes, //
>      };

What's the improvement in this change? Both of the ones factored out are already
correctly imported through prelude. Let's keep it as is.

> diff --git a/drivers/gpu/nova-core/nova_core.rs b/drivers/gpu/nova-core/nova_core.rs
> index c1121e7c64c5..b5caf1044697 100644
> --- a/drivers/gpu/nova-core/nova_core.rs
> +++ b/drivers/gpu/nova-core/nova_core.rs
> @@ -18,7 +18,7 @@
>  mod sbuffer;
>  mod vbios;
>  
> -pub(crate) const MODULE_NAME: &kernel::str::CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
> +pub(crate) const MODULE_NAME: &core::ffi::CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
>  
>  kernel::module_pci_driver! {
>      type: driver::NovaCore,
>
> -- 
> 2.53.0

Re: [PATCH v3 7/8] gpu: nova-core: use core library's CStr instead of kernel one

[Alexandre Courbot]

On Tue Feb 17, 2026 at 8:25 PM JST, Danilo Krummrich wrote:
> On Tue Feb 17, 2026 at 3:45 AM CET, Alexandre Courbot wrote:
>> The kernel's own CStr type has been replaced by the one in the core
>> library, and is now an alias to the latter. Change our imports to
>> directly reference the actual type.
>>
>> Reviewed-by: Lyude Paul <lyude@redhat.com>
>> Reviewed-by: Gary Guo <gary@garyguo.net>
>> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
>> ---
>>  drivers/gpu/nova-core/firmware.rs     | 2 +-
>>  drivers/gpu/nova-core/firmware/gsp.rs | 6 +++++-
>>  drivers/gpu/nova-core/nova_core.rs    | 2 +-
>>  3 files changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
>> index 68779540aa28..2f7249383e51 100644
>> --- a/drivers/gpu/nova-core/firmware.rs
>> +++ b/drivers/gpu/nova-core/firmware.rs
>> @@ -424,7 +424,7 @@ const fn make_entry_chipset(self, chipset: &str) -> Self {
>>      }
>>  
>>      pub(crate) const fn create(
>> -        module_name: &'static kernel::str::CStr,
>> +        module_name: &'static core::ffi::CStr,
>>      ) -> firmware::ModInfoBuilder<N> {
>>          let mut this = Self(firmware::ModInfoBuilder::new(module_name));
>>          let mut i = 0;
>> diff --git a/drivers/gpu/nova-core/firmware/gsp.rs b/drivers/gpu/nova-core/firmware/gsp.rs
>> index 9488a626352f..ae3f6581c5b6 100644
>> --- a/drivers/gpu/nova-core/firmware/gsp.rs
>> +++ b/drivers/gpu/nova-core/firmware/gsp.rs
>> @@ -32,9 +32,13 @@
>>  /// that scheme before nova-core becomes stable, which means this module will eventually be
>>  /// removed.
>>  mod elf {
>> +    use core::{
>> +        ffi::CStr,
>> +        mem::size_of, //
>> +    };
>> +
>>      use kernel::{
>>          bindings,
>> -        prelude::*,
>>          transmute::FromBytes, //
>>      };
>
> What's the improvement in this change? Both of the ones factored out are already
> correctly imported through prelude. Let's keep it as is.

Mmm, either they weren't at the time I initially wrote this patch, or
I've been careless (the latter being more likely). I'll remove this.

[PATCH v3 8/8] gpu: nova-core: gsp: use available device reference

[Alexandre Courbot]

We already have a regular reference to the `Device`, so we don't need to
repeatedly acquire one in this method.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/gsp/boot.rs | 34 ++++++++--------------------------
 1 file changed, 8 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/boot.rs b/drivers/gpu/nova-core/gsp/boot.rs
index be427fe26a58..93651243ab1b 100644
--- a/drivers/gpu/nova-core/gsp/boot.rs
+++ b/drivers/gpu/nova-core/gsp/boot.rs
@@ -170,15 +170,10 @@ pub(crate) fn boot(
             Some(libos_handle as u32),
             Some((libos_handle >> 32) as u32),
         )?;
-        dev_dbg!(
-            pdev.as_ref(),
-            "GSP MBOX0: {:#x}, MBOX1: {:#x}\n",
-            mbox0,
-            mbox1
-        );
+        dev_dbg!(dev, "GSP MBOX0: {:#x}, MBOX1: {:#x}\n", mbox0, mbox1);
 
         dev_dbg!(
-            pdev.as_ref(),
+            dev,
             "Using SEC2 to load and run the booter_load firmware...\n"
         );
 
@@ -190,19 +185,10 @@ pub(crate) fn boot(
             Some(wpr_handle as u32),
             Some((wpr_handle >> 32) as u32),
         )?;
-        dev_dbg!(
-            pdev.as_ref(),
-            "SEC2 MBOX0: {:#x}, MBOX1{:#x}\n",
-            mbox0,
-            mbox1
-        );
+        dev_dbg!(dev, "SEC2 MBOX0: {:#x}, MBOX1{:#x}\n", mbox0, mbox1);
 
         if mbox0 != 0 {
-            dev_err!(
-                pdev.as_ref(),
-                "Booter-load failed with error {:#x}\n",
-                mbox0
-            );
+            dev_err!(dev, "Booter-load failed with error {:#x}\n", mbox0);
             return Err(ENODEV);
         }
 
@@ -216,11 +202,7 @@ pub(crate) fn boot(
             Delta::from_secs(5),
         )?;
 
-        dev_dbg!(
-            pdev.as_ref(),
-            "RISC-V active? {}\n",
-            gsp_falcon.is_riscv_active(bar),
-        );
+        dev_dbg!(dev, "RISC-V active? {}\n", gsp_falcon.is_riscv_active(bar),);
 
         // Create and run the GSP sequencer.
         let seq_params = GspSequencerParams {
@@ -228,7 +210,7 @@ pub(crate) fn boot(
             libos_dma_handle: libos_handle,
             gsp_falcon,
             sec2_falcon,
-            dev: pdev.as_ref().into(),
+            dev: dev.into(),
             bar,
         };
         GspSequencer::run(&mut self.cmdq, seq_params)?;
@@ -239,8 +221,8 @@ pub(crate) fn boot(
         // Obtain and display basic GPU information.
         let info = commands::get_gsp_info(&mut self.cmdq, bar)?;
         match info.gpu_name() {
-            Ok(name) => dev_info!(pdev.as_ref(), "GPU name: {}\n", name),
-            Err(e) => dev_warn!(pdev.as_ref(), "GPU name unavailable: {:?}\n", e),
+            Ok(name) => dev_info!(dev, "GPU name: {}\n", name),
+            Err(e) => dev_warn!(dev, "GPU name unavailable: {:?}\n", e),
         }
 
         Ok(())

-- 
2.53.0

Re: [PATCH v3 8/8] gpu: nova-core: gsp: use available device reference

[Danilo Krummrich]

On Tue Feb 17, 2026 at 3:45 AM CET, Alexandre Courbot wrote:
> We already have a regular reference to the `Device`, so we don't need to
> repeatedly acquire one in this method.
>
> Reviewed-by: Gary Guo <gary@garyguo.net>
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

This conflicts with [1]. I think I will just drop [1] from my queue, since for
nova-core specifically using the base Device here may be better, as eventually
nova-core will work with both a pci::Device and a platform::Device.

(Which also reminds me that at some point we have to treat pci::Bar as generic
I/O backend.)

I hope we can actually keep as many code paths in common as I imagine.

[1] https://lore.kernel.org/all/20260123175854.176735-7-gary@kernel.org/

Re: [PATCH v3 0/8] gpu: nova-core: miscellaneous improvements

[Danilo Krummrich]

On Tue Feb 17, 2026 at 3:45 AM CET, Alexandre Courbot wrote:
> A few simple, loosely-related small improvements for nova-core,
> including reporting unprocessed data in GSP messages, removal of
> unnecessary code in GSP and the sequencer, and leveraging the Zeroable
> derive macro and core library's CStr. Probably nothing too
> controversial, so I plan on applying it soon after -rc1 gets released.
>
> This revision is based on master.
>
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

With my comments in patch 7 addressed,

Reviewed-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH v3 0/8] gpu: nova-core: miscellaneous improvements

[Alexandre Courbot]

On Tue Feb 17, 2026 at 8:33 PM JST, Danilo Krummrich wrote:
> On Tue Feb 17, 2026 at 3:45 AM CET, Alexandre Courbot wrote:
>> A few simple, loosely-related small improvements for nova-core,
>> including reporting unprocessed data in GSP messages, removal of
>> unnecessary code in GSP and the sequencer, and leveraging the Zeroable
>> derive macro and core library's CStr. Probably nothing too
>> controversial, so I plan on applying it soon after -rc1 gets released.
>>
>> This revision is based on master.
>>
>> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
>
> With my comments in patch 7 addressed,
>
> Reviewed-by: Danilo Krummrich <dakr@kernel.org>

Thanks! Staging for applying after -rc1 is released, with the comments
on patch 7 addressed.

Re: [PATCH v3 0/8] gpu: nova-core: miscellaneous improvements

[Alexandre Courbot]

On Thu Feb 19, 2026 at 11:12 AM JST, Alexandre Courbot wrote:
> On Tue Feb 17, 2026 at 8:33 PM JST, Danilo Krummrich wrote:
>> On Tue Feb 17, 2026 at 3:45 AM CET, Alexandre Courbot wrote:
>>> A few simple, loosely-related small improvements for nova-core,
>>> including reporting unprocessed data in GSP messages, removal of
>>> unnecessary code in GSP and the sequencer, and leveraging the Zeroable
>>> derive macro and core library's CStr. Probably nothing too
>>> controversial, so I plan on applying it soon after -rc1 gets released.
>>>
>>> This revision is based on master.
>>>
>>> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
>>
>> With my comments in patch 7 addressed,
>>
>> Reviewed-by: Danilo Krummrich <dakr@kernel.org>
>
> Thanks! Staging for applying after -rc1 is released, with the comments
> on patch 7 addressed.

Pushed into `drm-rust-next`, with the exception of the last patch which
has been superseeded by [1].

[1] https://patch.msgid.link/20260123175854.176735-7-gary@kernel.org