Re: [PATCH v3 10/14] gpu: nova-core: sequencer: Implement basic core operations

[Joel Fernandes <joelagnelf@nvidia.com>]

On 11/11/2025 4:12 PM, Lyude Paul wrote:
> On Thu, 2025-11-06 at 18:11 -0500, Joel Fernandes wrote:
>> These opcodes implement various falcon-related boot operations: reset,
>> start, wait-for-halt.
>>
>> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
>> ---
>>  drivers/gpu/nova-core/gsp/sequencer.rs | 27 ++++++++++++++++++++++++++
>>  1 file changed, 27 insertions(+)
>>
>> diff --git a/drivers/gpu/nova-core/gsp/sequencer.rs b/drivers/gpu/nova-core/gsp/sequencer.rs
>> index 17118967a8d4..0192ac61df4c 100644
>> --- a/drivers/gpu/nova-core/gsp/sequencer.rs
>> +++ b/drivers/gpu/nova-core/gsp/sequencer.rs
>> @@ -49,6 +49,9 @@ pub(crate) enum GspSeqCmd {
>>      RegPoll(fw::GSP_SEQ_BUF_PAYLOAD_REG_POLL),
>>      DelayUs(fw::GSP_SEQ_BUF_PAYLOAD_DELAY_US),
>>      RegStore(fw::GSP_SEQ_BUF_PAYLOAD_REG_STORE),
>> +    CoreReset,
>> +    CoreStart,
>> +    CoreWaitForHalt,
>>  }
>>  
>>  impl GspSeqCmd {
>> @@ -75,6 +78,11 @@ pub(crate) fn from_fw_cmd(cmd: &fw::GSP_SEQUENCER_BUFFER_CMD) -> Result<Self> {
>>                  // SAFETY: We're using the union field that corresponds to the opCode.
>>                  Ok(GspSeqCmd::RegStore(unsafe { cmd.payload.regStore }))
>>              }
>> +            fw::GSP_SEQ_BUF_OPCODE_GSP_SEQ_BUF_OPCODE_CORE_RESET => Ok(GspSeqCmd::CoreReset),
>> +            fw::GSP_SEQ_BUF_OPCODE_GSP_SEQ_BUF_OPCODE_CORE_START => Ok(GspSeqCmd::CoreStart),
>> +            fw::GSP_SEQ_BUF_OPCODE_GSP_SEQ_BUF_OPCODE_CORE_WAIT_FOR_HALT => {
>> +                Ok(GspSeqCmd::CoreWaitForHalt)
>> +            }
>>              _ => Err(EINVAL),
>>          }
>>      }
>> @@ -96,6 +104,9 @@ pub(crate) fn new(data: &[u8], dev: &device::Device<device::Bound>) -> Result<Se
>>      pub(crate) fn size_bytes(&self) -> usize {
>>          let opcode_size = size_of::<fw::GSP_SEQ_BUF_OPCODE>();
>>          match self {
>> +            // Each simple command type just adds 4 bytes (opcode_size) for the header.
>> +            GspSeqCmd::CoreReset | GspSeqCmd::CoreStart | GspSeqCmd::CoreWaitForHalt => opcode_size,
>> +
>>              // For commands with payloads, add the payload size in bytes.
>>              GspSeqCmd::RegWrite(_) => opcode_size + size_of::<fw::GSP_SEQ_BUF_PAYLOAD_REG_WRITE>(),
>>              GspSeqCmd::RegModify(_) => {
>> @@ -200,6 +211,22 @@ fn run(&self, seq: &GspSequencer<'_>) -> Result {
>>              GspSeqCmd::RegPoll(cmd) => cmd.run(seq),
>>              GspSeqCmd::DelayUs(cmd) => cmd.run(seq),
>>              GspSeqCmd::RegStore(cmd) => cmd.run(seq),
>> +            GspSeqCmd::CoreReset => {
>> +                dev_dbg!(seq.dev, "CoreReset\n");
>> +                seq.gsp_falcon.reset(seq.bar)?;
>> +                seq.gsp_falcon.dma_reset(seq.bar);
>> +                Ok(())
>> +            }
>> +            GspSeqCmd::CoreStart => {
>> +                dev_dbg!(seq.dev, "CoreStart\n");
>> +                seq.gsp_falcon.start(seq.bar)?;
>> +                Ok(())
>> +            }
>> +            GspSeqCmd::CoreWaitForHalt => {
>> +                dev_dbg!(seq.dev, "CoreWaitForHalt\n");
>> +                seq.gsp_falcon.wait_till_halted(seq.bar)?;
>> +                Ok(())
> 
> Are we still planning on getting rid of these dev_dbg! calls?
> 
Yes, already done for v4 and posting soon.

Thanks.