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path: root/drivers/gpu/nova-core/gsp/cmdq.rs
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2026-03-11gpu: nova-core: gsp: fix UB in DmaGspMem pointer accessorsDanilo Krummrich
The DmaGspMem pointer accessor methods (gsp_write_ptr, gsp_read_ptr, cpu_read_ptr, cpu_write_ptr, advance_cpu_read_ptr, advance_cpu_write_ptr) dereference a raw pointer to DMA memory, creating an intermediate reference before calling volatile read/write methods. This is undefined behavior since DMA memory can be concurrently modified by the device. Fix this by moving the implementations into a gsp_mem module in fw.rs that uses the dma_read!() / dma_write!() macros, making the original methods on DmaGspMem thin forwarding wrappers. An alternative approach would have been to wrap the shared memory in Opaque, but that would have required even more unsafe code. Since the gsp_mem module lives in fw.rs (to access firmware-specific binding field names), GspMem, Msgq and their relevant fields are temporarily widened to pub(super). This will be reverted once IoView projections are available. Cc: Gary Guo <gary@garyguo.net> Closes: https://lore.kernel.org/nouveau/DGUT14ILG35P.1UMNRKU93JUM1@kernel.org/ Fixes: 75f6b1de8133 ("gpu: nova-core: gsp: Add GSP command queue bindings and handling") Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Link: https://patch.msgid.link/20260309225408.27714-1-dakr@kernel.org [ Use pub(super) where possible; replace bitwise-and with modulo operator analogous to [1]. - Danilo ] Link: https://lore.kernel.org/all/20260129-nova-core-cmdq1-v3-1-2ede85493a27@nvidia.com/ [1] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-03-10gpu: nova-core: fix stack overflow in GSP memory allocationTim Kovalenko
The `Cmdq::new` function was allocating a `PteArray` struct on the stack and was causing a stack overflow with 8216 bytes. Modify the `PteArray` to calculate and write the Page Table Entries directly into the coherent DMA buffer one-by-one. This reduces the stack usage quite a lot. Reported-by: Gary Guo <gary@garyguo.net> Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/509436-Nova/topic/.60Cmdq.3A.3Anew.60.20uses.20excessive.20stack.20size/near/570375549 Link: https://lore.kernel.org/rust-for-linux/CANiq72mAQxbRJZDnik3Qmd4phvFwPA01O2jwaaXRh_T+2=L-qA@mail.gmail.com/ Fixes: f38b4f105cfc ("gpu: nova-core: Create initial Gsp") Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Tim Kovalenko <tim.kovalenko@proton.me> Link: https://patch.msgid.link/20260309-drm-rust-next-v4-4-4ef485b19a4c@proton.me [ * Use PteArray::entry() in LogBuffer::new(), * Add TODO comment to use IoView projections once available, * Add PTE_ARRAY_SIZE constant to avoid duplication. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-03-07rust: dma: use pointer projection infra for `dma_{read,write}` macroGary Guo
Current `dma_read!`, `dma_write!` macros also use a custom `addr_of!()`-based implementation for projecting pointers, which has soundness issue as it relies on absence of `Deref` implementation on types. It also has a soundness issue where it does not protect against unaligned fields (when `#[repr(packed)]` is used) so it can generate misaligned accesses. This commit migrates them to use the general pointer projection infrastructure, which handles these cases correctly. As part of migration, the macro is updated to have an improved surface syntax. The current macro have dma_read!(a.b.c[d].e.f) to mean `a.b.c` is a DMA coherent allocation and it should project into it with `[d].e.f` and do a read, which is confusing as it makes the indexing operator integral to the macro (so it will break if you have an array of `CoherentAllocation`, for example). This also is problematic as we would like to generalize `CoherentAllocation` from just slices to arbitrary types. Make the macro expects `dma_read!(path.to.dma, .path.inside.dma)` as the canonical syntax. The index operator is no longer special and is just one type of projection (in additional to field projection). Similarly, make `dma_write!(path.to.dma, .path.inside.dma, value)` become the canonical syntax for writing. Another issue of the current macro is that it is always fallible. This makes sense with existing design of `CoherentAllocation`, but once we support fixed size arrays with `CoherentAllocation`, it is desirable to have the ability to perform infallible indexing as well, e.g. doing a `[0]` index of `[Foo; 2]` is okay and can be checked at build-time, so forcing falliblity is non-ideal. To capture this, the macro is changed to use `[idx]` as infallible projection and `[idx]?` as fallible index projection (those syntax are part of the general projection infra). A benefit of this is that while individual indexing operation may fail, the overall read/write operation is not fallible. Fixes: ad2907b4e308 ("rust: add dma coherent allocator abstraction") Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260302164239.284084-4-gary@kernel.org [ Capitalize safety comments; slightly improve wording in doc-comments. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16Merge tag 'v6.19-rc5' into drm-rust-nextDanilo Krummrich
We need the drm-rust fixes from -rc5 in here for nova-core to build on top of. Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-12gpu: nova-core: add missing newlines to several print stringsTimur Tabi
Although the dev_xx!() macro calls do not technically require terminating newlines for the format strings, they should be added anyway to maintain consistency, both within Rust code and with the C versions. Signed-off-by: Timur Tabi <ttabi@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Link: https://patch.msgid.link/20260107201647.2490140-2-ttabi@nvidia.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-12-16gpu: nova-core: gsp: fix length of received messagesAlexandre Courbot
The size of messages' payload is miscalculated, leading to extra data passed to the message handler. While this is not a problem with our current set of commands, others with a variable-length payload may misbehave. Fix this by introducing a method returning the payload size and using it. Fixes: 75f6b1de8133 ("gpu: nova-core: gsp: Add GSP command queue bindings and handling") Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://patch.msgid.link/20251216-nova-fixes-v3-2-c7469a71f7c4@nvidia.com [acourbot@nvidia.com: update `PANIC:` comments as pointed out by Joel.] Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
2025-11-15gpu: nova-core: Implement the GSP sequencerJoel Fernandes
Implement the GSP sequencer which culminates in INIT_DONE message being received from the GSP indicating that the GSP has successfully booted. This is just initial sequencer support, the actual commands will be added in the next patches. Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com> [acourbot@nvidia.com: move GspSequencerInfo definition before its impl blocks and rename it to GspSequence, adapt imports in sequencer.rs to new formatting rules, remove `timeout` argument to harmonize with other commands.] Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Message-ID: <20251114195552.739371-8-joelagnelf@nvidia.com>
2025-11-14gpu: nova-core: gsp: Add SetSystemInfo commandAlistair Popple
Add support for sending the SetSystemInfo command, which provides required hardware information to the GSP and is critical to its initialization. Signed-off-by: Alistair Popple <apopple@nvidia.com> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Message-ID: <20251110-gsp_boot-v9-11-8ae4058e3c0e@nvidia.com>
2025-11-14gpu: nova-core: gsp: Create rmargsAlistair Popple
Initialise the GSP resource manager arguments (rmargs) which provides initialisation parameters to the GSP firmware during boot. The rmargs structure contains arguments to configure the GSP message/command queue location. These are mapped for coherent DMA and added to the libos data structure for access when booting GSP. Signed-off-by: Alistair Popple <apopple@nvidia.com> Co-developed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Message-ID: <20251110-gsp_boot-v9-10-8ae4058e3c0e@nvidia.com>
2025-11-14gpu: nova-core: gsp: Add GSP command queue bindings and handlingAlistair Popple
This commit introduces core infrastructure for handling GSP command and message queues in the nova-core driver. The command queue system enables bidirectional communication between the host driver and GSP firmware through a remote message passing interface. The interface is based on passing serialised data structures over a ring buffer with separate transmit and receive queues. Commands are sent by writing to the CPU transmit queue and waiting for completion via the receive queue. To ensure safety mutable or immutable (depending on whether it is a send or receive operation) references are taken on the command queue when allocating the message to write/read to. This ensures message memory remains valid and the command queue can't be mutated whilst an operation is in progress. Currently this is only used by the probe() routine and therefore can only used by a single thread of execution. Locking to enable safe access from multiple threads will be introduced in a future series when that becomes necessary. Signed-off-by: Alistair Popple <apopple@nvidia.com> Co-developed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Message-ID: <20251110-gsp_boot-v9-9-8ae4058e3c0e@nvidia.com>