[PATCH v5 08/13] gpu: nova-core: sequencer: Add register opcodes

Joel Fernandes
Fri, 14 Nov 2025 19:55:47 -0000

These opcodes are used for register write, modify, poll and store (save)
sequencer operations.

Signed-off-by: Joel Fernandes <joelagnelf at nvidia.com>
---
 drivers/gpu/nova-core/gsp/fw.rs        |   4 -
 drivers/gpu/nova-core/gsp/sequencer.rs | 120 ++++++++++++++++++++++---
 2 files changed, 109 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 6d58042bc9e8..376c10cc8003 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -389,7 +389,6 @@ fn from(value: SeqBufOpcode) -> Self {
 #[derive(Copy, Clone)]
 pub(crate) struct RegWritePayload(r570_144::GSP_SEQ_BUF_PAYLOAD_REG_WRITE);

-#[expect(unused)]
 impl RegWritePayload {
     /// Returns the register address.
     pub(crate) fn addr(&self) -> u32 {
@@ -413,7 +412,6 @@ unsafe impl AsBytes for RegWritePayload {}
 #[derive(Copy, Clone)]
 pub(crate) struct RegModifyPayload(r570_144::GSP_SEQ_BUF_PAYLOAD_REG_MODIFY);

-#[expect(unused)]
 impl RegModifyPayload {
     /// Returns the register address.
     pub(crate) fn addr(&self) -> u32 {
@@ -442,7 +440,6 @@ unsafe impl AsBytes for RegModifyPayload {}
 #[derive(Copy, Clone)]
 pub(crate) struct RegPollPayload(r570_144::GSP_SEQ_BUF_PAYLOAD_REG_POLL);

-#[expect(unused)]
 impl RegPollPayload {
     /// Returns the register address.
     pub(crate) fn addr(&self) -> u32 {
@@ -495,7 +492,6 @@ unsafe impl AsBytes for DelayUsPayload {}
 #[derive(Copy, Clone)]
 pub(crate) struct RegStorePayload(r570_144::GSP_SEQ_BUF_PAYLOAD_REG_STORE);

-#[expect(unused)]
 impl RegStorePayload {
     /// Returns the register address.
     pub(crate) fn addr(&self) -> u32 {
diff --git a/drivers/gpu/nova-core/gsp/sequencer.rs
b/drivers/gpu/nova-core/gsp/sequencer.rs
index c5ef3a33466a..b564523b64e7 100644
--- a/drivers/gpu/nova-core/gsp/sequencer.rs
+++ b/drivers/gpu/nova-core/gsp/sequencer.rs
@@ -4,9 +4,13 @@

 use core::{
     array,
-    mem::size_of, //
+    mem::{
+        size_of,
+        size_of_val, //
+    }, //
 };
 use kernel::device;
+use kernel::io::poll::read_poll_timeout;
 use kernel::prelude::*;
 use kernel::time::Delta;
 use kernel::transmute::FromBytes;
@@ -56,18 +60,50 @@ struct GspSequencerInfo {

 /// GSP Sequencer Command types with payload data.
 /// Commands have an opcode and an opcode-dependent struct.
-#[allow(dead_code)]
-pub(crate) enum GspSeqCmd {}
+#[allow(clippy::enum_variant_names)]
+pub(crate) enum GspSeqCmd {
+    RegWrite(fw::RegWritePayload),
+    RegModify(fw::RegModifyPayload),
+    RegPoll(fw::RegPollPayload),
+    RegStore(fw::RegStorePayload),
+}

 impl GspSeqCmd {
     /// Creates a new `GspSeqCmd` from raw data returning the command and its
size in bytes.
-    pub(crate) fn new(data: &[u8], _dev: &device::Device) ->
Result<(Self, usize)> {
-        let _fw_cmd = fw::SequencerBufferCmd::from_bytes(data).ok_or(EINVAL)?;
-        let _opcode_size = core::mem::size_of::<u32>();
+    pub(crate) fn new(data: &[u8], dev: &device::Device) ->
Result<(Self, usize)> {
+        let fw_cmd = fw::SequencerBufferCmd::from_bytes(data).ok_or(EINVAL)?;
+        let opcode_size = core::mem::size_of::<u32>();
+
+        let (cmd, size) = match fw_cmd.opcode()? {
+            fw::SeqBufOpcode::RegWrite => {
+                let payload = fw_cmd.reg_write_payload()?;
+                let size = opcode_size + size_of_val(&payload);
+                (GspSeqCmd::RegWrite(payload), size)
+            }
+            fw::SeqBufOpcode::RegModify => {
+                let payload = fw_cmd.reg_modify_payload()?;
+                let size = opcode_size + size_of_val(&payload);
+                (GspSeqCmd::RegModify(payload), size)
+            }
+            fw::SeqBufOpcode::RegPoll => {
+                let payload = fw_cmd.reg_poll_payload()?;
+                let size = opcode_size + size_of_val(&payload);
+                (GspSeqCmd::RegPoll(payload), size)
+            }
+            fw::SeqBufOpcode::RegStore => {
+                let payload = fw_cmd.reg_store_payload()?;
+                let size = opcode_size + size_of_val(&payload);
+                (GspSeqCmd::RegStore(payload), size)
+            }
+            _ => return Err(EINVAL),
+        };
+
+        if data.len() < size {
+            dev_err!(dev, "Data is not enough for command");
+            return Err(EINVAL);
+        }

-        // NOTE: At this commit, NO opcodes exist yet, so just return error.
-        // Later commits will add match arms here.
-        Err(EINVAL)
+        Ok((cmd, size))
     }
 }

@@ -95,12 +131,74 @@ pub(crate) trait GspSeqCmdRunner {
     fn run(&self, sequencer: &GspSequencer<'_>) -> Result;
 }

-impl GspSeqCmdRunner for GspSeqCmd {
-    fn run(&self, _seq: &GspSequencer<'_>) -> Result {
+impl GspSeqCmdRunner for fw::RegWritePayload {
+    fn run(&self, sequencer: &GspSequencer<'_>) -> Result
{
+        let addr = self.addr() as usize;
+        let val = self.val();
+        let _ = sequencer.bar.try_write32(val, addr);
         Ok(())
     }
 }

+impl GspSeqCmdRunner for fw::RegModifyPayload {
+    fn run(&self, sequencer: &GspSequencer<'_>) -> Result
{
+        let addr = self.addr() as usize;
+        if let Ok(temp) = sequencer.bar.try_read32(addr) {
+            let _ = sequencer
+                .bar
+                .try_write32((temp & !self.mask()) | self.val(), addr);
+        }
+        Ok(())
+    }
+}
+
+impl GspSeqCmdRunner for fw::RegPollPayload {
+    fn run(&self, sequencer: &GspSequencer<'_>) -> Result
{
+        let addr = self.addr() as usize;
+
+        // Default timeout to 4 seconds.
+        let timeout_us = if self.timeout() == 0 {
+            4_000_000
+        } else {
+            i64::from(self.timeout())
+        };
+
+        // First read.
+        sequencer.bar.try_read32(addr)?;
+
+        // Poll the requested register with requested timeout.
+        read_poll_timeout(
+            || sequencer.bar.try_read32(addr),
+            |current| (current & self.mask()) == self.val(),
+            Delta::ZERO,
+            Delta::from_micros(timeout_us),
+        )
+        .map(|_| ())
+    }
+}
+
+impl GspSeqCmdRunner for fw::RegStorePayload {
+    fn run(&self, sequencer: &GspSequencer<'_>) -> Result
{
+        let addr = self.addr() as usize;
+        let _index = self.index();
+
+        let _val = sequencer.bar.try_read32(addr)?;
+
+        Ok(())
+    }
+}
+
+impl GspSeqCmdRunner for GspSeqCmd {
+    fn run(&self, seq: &GspSequencer<'_>) -> Result {
+        match self {
+            GspSeqCmd::RegWrite(cmd) => cmd.run(seq),
+            GspSeqCmd::RegModify(cmd) => cmd.run(seq),
+            GspSeqCmd::RegPoll(cmd) => cmd.run(seq),
+            GspSeqCmd::RegStore(cmd) => cmd.run(seq),
+        }
+    }
+}
+
 /// Iterator over GSP sequencer commands.
 pub(crate) struct GspSeqIter<'a> {
     /// Command data buffer.
--
2.34.1