On 8/28/26 6:22 PM, John Hubbard wrote:
> I'm posting a v2 because there have been some significant changes, as a
> result of the v1 review, plus Danilo's new IRQ commits that I've rebased
> onto.
There was a failure in git-send-email part way through. I'll attempt to
resend, once I figure out what went wrong.
Only the cover letter and the first 4 patches got sent.
thanks,
--
John Hubbard
>
> This series adds support for GIN, the GPU Interrupt and Notification
> unit, which is the GPU's interrupt controller, so that GSP events reach
> the driver as interrupts instead of only when the driver polls.
>
> The design uses a threaded IRQ handler. The top half touches only
> GPU registers, while the threaded bottom half drains the message queue.
>
> Fine-grained locking is left for a follow-up patchset, I'm working on
> that next. For now, there is just a big ugly lock around anything that
> even gets close to the GSP message queue. :)
>
> This is based on drm-rust-next, plus the six commits of Danilo
> Krummrich's PCI interrupt-vector series [1], which I've cherry-picked
> from mainline for now.
>
> There is a git branch with the patches as applied to drm-rust-next:
>
> https://github.com/johnhubbard/linux/tree/nova-core-gin-interrupt-tree-v2/
>
> Changes in v2:
>
> * Rebased onto current drm-rust-next. The PCI interrupt-vector rework
> that v1 patches 2 and 3 proposed is in mainline now as Danilo's series
> [1], so both are dropped. This series carries those six commits as
> prerequisites until drm-rust-next picks them up.
>
> * nova-core uses the merged API: the driver's device data owns the
> vector allocation under an explicit lifetime rather than through
> devres, and each handler takes an IrqRequest for its own subtree's
> vector.
>
> * Dropped "allocate PCI MSI vector during probe" (v1 patch 4). What it
> added is replaced by patch 6, and its commit message justified MSI
> with a VFIO claim that does not hold. nova-core still allocates MSI-X
> or MSI, and no longer falls back to INTx. (Danilo)
>
> * Dropped the type-invariant documentation and the SAFETY rewrites from
> the wait_for_completion_timeout() patch, leaving only the new method
> itself. (Alexandre)
>
> * New: declare pci::IrqType and IrqTypes with impl_flags, so a call site
> reads IrqType::MsiX | IrqType::Msi. (Gary)
>
> * New: the GIN vector and subtree newtypes. A vector, a leaf index, a
> set of vectors within one leaf, one subtree, a set of subtrees, and a
> leaf count are separate types now, so a leaf mask cannot be passed
> where a TOP bit belongs. The HAL returns a LeafCount rather than a
> usize. GSP_LEAF and GSP_BIT are gone, along with the
> LeafIndex::new::<GSP_LEAF>() calls. (Danilo)
>
> * Merged the tree API patch into the vector allocation patch, and moved
> both after the HAL. Tree owns the BAR mapping, so no tree method takes
> a bar argument. The Leaf<Idle>/Leaf<Pending> type state gives way to a
> LeafPending newtype that only Tree::read_pending hands out, and enable
> and disable are Tree methods. (Danilo)
>
> * Added LeafEnableGuard and TopEnableGuard. The self-test's teardown
> guard and GspIrq's open-coded destructor are both gone, and probe no
> longer needs a separate interrupt-enable step. (Danilo)
>
> * Moved the GIN and MSI EOI register definitions to irq/regs.rs.
> (Danilo)
>
> * 13 KUnit tests rather than 14. The tree tests now cover the newtypes,
> and testing those needs no BAR mapping. One test went away because a
> leaf count derives its subtree set by construction.
>
> Tested on Turing, Ampere, Blackwell GPUs.
>
> One known gap: driver_read_area still reads the GSP producer pointer
> with no acquire barrier. Gary Guo's barrier series puts dma_mb(Read) at
> exactly that point [2], so let's just wait for his fix to land.
>
> [1] https://lore.kernel.org/all/20260813165234.620555-1-dakr@kernel.org/
> [2] https://lore.kernel.org/all/20260609-rust-barrier-v2-4-30fcc48e1cd0@garyguo.net/
>
>
> Joel Fernandes (2):
> rust: sync: completion: add wait_for_completion_timeout()
> gpu: nova-core: add the GIN interrupt tree and allocate its vectors
>
> John Hubbard (13):
> rust: pci: declare IrqType and IrqTypes with impl_flags
> gpu: nova-core: add the GIN CPU interrupt tree and MSI EOI registers
> gpu: nova-core: add the GIN vector and subtree newtypes
> gpu: nova-core: add the per-architecture GIN CPU interrupt HAL
> gpu: nova-core: add an interrupt delivery self-test
> gpu: nova-core: dispatch GSP events instead of discarding them
> gpu: nova-core: match GSP RPC replies by sequence, not just function
> gpu: nova-core: recover the GSP receive path from corrupt framing
> gpu: nova-core: bound a GSP wait by a single deadline
> gpu: nova-core: drive GSP events with the SWGEN0 interrupt
> gpu: nova-core: retrigger the GSP falcon and clear every latched cause
> gpu: nova-core: add KUnit tests for the interrupt tree and HALs
> gpu: nova-core: document the GIN interrupt controller and GSP events
>
> Documentation/gpu/nova/core/interrupts.rst | 686 ++++++++++++++++++++
> Documentation/gpu/nova/index.rst | 1 +
> drivers/gpu/nova-core/Kconfig | 15 +
> drivers/gpu/nova-core/driver.rs | 55 +-
> drivers/gpu/nova-core/falcon/gsp.rs | 71 +-
> drivers/gpu/nova-core/falcon/hal.rs | 32 +
> drivers/gpu/nova-core/gpu.rs | 28 +-
> drivers/gpu/nova-core/gsp.rs | 17 +-
> drivers/gpu/nova-core/gsp/cmdq.rs | 286 ++++++--
> drivers/gpu/nova-core/gsp/commands.rs | 8 +-
> drivers/gpu/nova-core/gsp/fw.rs | 13 +-
> drivers/gpu/nova-core/gsp/sequencer.rs | 8 +-
> drivers/gpu/nova-core/irq.rs | 105 +++
> drivers/gpu/nova-core/irq/doorbell_test.rs | 298 +++++++++
> drivers/gpu/nova-core/irq/gsp.rs | 232 +++++++
> drivers/gpu/nova-core/irq/hal.rs | 192 ++++++
> drivers/gpu/nova-core/irq/hal/gh100.rs | 31 +
> drivers/gpu/nova-core/irq/hal/tu102.rs | 30 +
> drivers/gpu/nova-core/irq/interrupt_tree.rs | 615 ++++++++++++++++++
> drivers/gpu/nova-core/irq/regs.rs | 71 ++
> drivers/gpu/nova-core/nova_core.rs | 1 +
> drivers/gpu/nova-core/regs.rs | 24 +
> rust/kernel/pci/irq.rs | 68 +-
> rust/kernel/sync/completion.rs | 23 +-
> 24 files changed, 2767 insertions(+), 143 deletions(-)
> create mode 100644 Documentation/gpu/nova/core/interrupts.rst
> create mode 100644 drivers/gpu/nova-core/irq.rs
> create mode 100644 drivers/gpu/nova-core/irq/doorbell_test.rs
> create mode 100644 drivers/gpu/nova-core/irq/gsp.rs
> create mode 100644 drivers/gpu/nova-core/irq/hal.rs
> create mode 100644 drivers/gpu/nova-core/irq/hal/gh100.rs
> create mode 100644 drivers/gpu/nova-core/irq/hal/tu102.rs
> create mode 100644 drivers/gpu/nova-core/irq/interrupt_tree.rs
> create mode 100644 drivers/gpu/nova-core/irq/regs.rs
>