* [PATCH v6 1/9] gpu: nova-core: gsp: sort `MsgFunction` variants alphabetically
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
@ 2026-03-06 7:21 ` Eliot Courtney
2026-03-06 7:21 ` [PATCH v6 2/9] gpu: nova-core: gsp: add mechanism to wait for space on command queue Eliot Courtney
` (8 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:21 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
There is no particular order required here and keeping them alphabetical
will help preventing future mistakes.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/fw.rs | 67 +++++++++++++++++++++--------------------
1 file changed, 35 insertions(+), 32 deletions(-)
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index f1797e1f0d9d..4b998485360b 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -191,34 +191,34 @@ pub(crate) fn new(gsp_firmware: &GspFirmware, fb_layout: &FbLayout) -> Self {
#[repr(u32)]
pub(crate) enum MsgFunction {
// Common function codes
- Nop = bindings::NV_VGPU_MSG_FUNCTION_NOP,
- SetGuestSystemInfo = bindings::NV_VGPU_MSG_FUNCTION_SET_GUEST_SYSTEM_INFO,
- AllocRoot = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_ROOT,
+ AllocChannelDma = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CHANNEL_DMA,
+ AllocCtxDma = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CTX_DMA,
AllocDevice = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_DEVICE,
AllocMemory = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_MEMORY,
- AllocCtxDma = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CTX_DMA,
- AllocChannelDma = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CHANNEL_DMA,
- MapMemory = bindings::NV_VGPU_MSG_FUNCTION_MAP_MEMORY,
- BindCtxDma = bindings::NV_VGPU_MSG_FUNCTION_BIND_CTX_DMA,
AllocObject = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_OBJECT,
+ AllocRoot = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_ROOT,
+ BindCtxDma = bindings::NV_VGPU_MSG_FUNCTION_BIND_CTX_DMA,
Free = bindings::NV_VGPU_MSG_FUNCTION_FREE,
- Log = bindings::NV_VGPU_MSG_FUNCTION_LOG,
GetGspStaticInfo = bindings::NV_VGPU_MSG_FUNCTION_GET_GSP_STATIC_INFO,
- SetRegistry = bindings::NV_VGPU_MSG_FUNCTION_SET_REGISTRY,
- GspSetSystemInfo = bindings::NV_VGPU_MSG_FUNCTION_GSP_SET_SYSTEM_INFO,
+ GetStaticInfo = bindings::NV_VGPU_MSG_FUNCTION_GET_STATIC_INFO,
GspInitPostObjGpu = bindings::NV_VGPU_MSG_FUNCTION_GSP_INIT_POST_OBJGPU,
GspRmControl = bindings::NV_VGPU_MSG_FUNCTION_GSP_RM_CONTROL,
- GetStaticInfo = bindings::NV_VGPU_MSG_FUNCTION_GET_STATIC_INFO,
+ GspSetSystemInfo = bindings::NV_VGPU_MSG_FUNCTION_GSP_SET_SYSTEM_INFO,
+ Log = bindings::NV_VGPU_MSG_FUNCTION_LOG,
+ MapMemory = bindings::NV_VGPU_MSG_FUNCTION_MAP_MEMORY,
+ Nop = bindings::NV_VGPU_MSG_FUNCTION_NOP,
+ SetGuestSystemInfo = bindings::NV_VGPU_MSG_FUNCTION_SET_GUEST_SYSTEM_INFO,
+ SetRegistry = bindings::NV_VGPU_MSG_FUNCTION_SET_REGISTRY,
// Event codes
GspInitDone = bindings::NV_VGPU_MSG_EVENT_GSP_INIT_DONE,
+ GspLockdownNotice = bindings::NV_VGPU_MSG_EVENT_GSP_LOCKDOWN_NOTICE,
+ GspPostNoCat = bindings::NV_VGPU_MSG_EVENT_GSP_POST_NOCAT_RECORD,
GspRunCpuSequencer = bindings::NV_VGPU_MSG_EVENT_GSP_RUN_CPU_SEQUENCER,
- PostEvent = bindings::NV_VGPU_MSG_EVENT_POST_EVENT,
- RcTriggered = bindings::NV_VGPU_MSG_EVENT_RC_TRIGGERED,
MmuFaultQueued = bindings::NV_VGPU_MSG_EVENT_MMU_FAULT_QUEUED,
OsErrorLog = bindings::NV_VGPU_MSG_EVENT_OS_ERROR_LOG,
- GspPostNoCat = bindings::NV_VGPU_MSG_EVENT_GSP_POST_NOCAT_RECORD,
- GspLockdownNotice = bindings::NV_VGPU_MSG_EVENT_GSP_LOCKDOWN_NOTICE,
+ PostEvent = bindings::NV_VGPU_MSG_EVENT_POST_EVENT,
+ RcTriggered = bindings::NV_VGPU_MSG_EVENT_RC_TRIGGERED,
UcodeLibOsPrint = bindings::NV_VGPU_MSG_EVENT_UCODE_LIBOS_PRINT,
}
@@ -227,38 +227,41 @@ impl TryFrom<u32> for MsgFunction {
fn try_from(value: u32) -> Result<MsgFunction> {
match value {
- bindings::NV_VGPU_MSG_FUNCTION_NOP => Ok(MsgFunction::Nop),
- bindings::NV_VGPU_MSG_FUNCTION_SET_GUEST_SYSTEM_INFO => {
- Ok(MsgFunction::SetGuestSystemInfo)
- }
- bindings::NV_VGPU_MSG_FUNCTION_ALLOC_ROOT => Ok(MsgFunction::AllocRoot),
+ // Common function codes
+ bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CHANNEL_DMA => Ok(MsgFunction::AllocChannelDma),
+ bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CTX_DMA => Ok(MsgFunction::AllocCtxDma),
bindings::NV_VGPU_MSG_FUNCTION_ALLOC_DEVICE => Ok(MsgFunction::AllocDevice),
bindings::NV_VGPU_MSG_FUNCTION_ALLOC_MEMORY => Ok(MsgFunction::AllocMemory),
- bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CTX_DMA => Ok(MsgFunction::AllocCtxDma),
- bindings::NV_VGPU_MSG_FUNCTION_ALLOC_CHANNEL_DMA => Ok(MsgFunction::AllocChannelDma),
- bindings::NV_VGPU_MSG_FUNCTION_MAP_MEMORY => Ok(MsgFunction::MapMemory),
- bindings::NV_VGPU_MSG_FUNCTION_BIND_CTX_DMA => Ok(MsgFunction::BindCtxDma),
bindings::NV_VGPU_MSG_FUNCTION_ALLOC_OBJECT => Ok(MsgFunction::AllocObject),
+ bindings::NV_VGPU_MSG_FUNCTION_ALLOC_ROOT => Ok(MsgFunction::AllocRoot),
+ bindings::NV_VGPU_MSG_FUNCTION_BIND_CTX_DMA => Ok(MsgFunction::BindCtxDma),
bindings::NV_VGPU_MSG_FUNCTION_FREE => Ok(MsgFunction::Free),
- bindings::NV_VGPU_MSG_FUNCTION_LOG => Ok(MsgFunction::Log),
bindings::NV_VGPU_MSG_FUNCTION_GET_GSP_STATIC_INFO => Ok(MsgFunction::GetGspStaticInfo),
- bindings::NV_VGPU_MSG_FUNCTION_SET_REGISTRY => Ok(MsgFunction::SetRegistry),
- bindings::NV_VGPU_MSG_FUNCTION_GSP_SET_SYSTEM_INFO => Ok(MsgFunction::GspSetSystemInfo),
+ bindings::NV_VGPU_MSG_FUNCTION_GET_STATIC_INFO => Ok(MsgFunction::GetStaticInfo),
bindings::NV_VGPU_MSG_FUNCTION_GSP_INIT_POST_OBJGPU => {
Ok(MsgFunction::GspInitPostObjGpu)
}
bindings::NV_VGPU_MSG_FUNCTION_GSP_RM_CONTROL => Ok(MsgFunction::GspRmControl),
- bindings::NV_VGPU_MSG_FUNCTION_GET_STATIC_INFO => Ok(MsgFunction::GetStaticInfo),
+ bindings::NV_VGPU_MSG_FUNCTION_GSP_SET_SYSTEM_INFO => Ok(MsgFunction::GspSetSystemInfo),
+ bindings::NV_VGPU_MSG_FUNCTION_LOG => Ok(MsgFunction::Log),
+ bindings::NV_VGPU_MSG_FUNCTION_MAP_MEMORY => Ok(MsgFunction::MapMemory),
+ bindings::NV_VGPU_MSG_FUNCTION_NOP => Ok(MsgFunction::Nop),
+ bindings::NV_VGPU_MSG_FUNCTION_SET_GUEST_SYSTEM_INFO => {
+ Ok(MsgFunction::SetGuestSystemInfo)
+ }
+ bindings::NV_VGPU_MSG_FUNCTION_SET_REGISTRY => Ok(MsgFunction::SetRegistry),
+
+ // Event codes
bindings::NV_VGPU_MSG_EVENT_GSP_INIT_DONE => Ok(MsgFunction::GspInitDone),
+ bindings::NV_VGPU_MSG_EVENT_GSP_LOCKDOWN_NOTICE => Ok(MsgFunction::GspLockdownNotice),
+ bindings::NV_VGPU_MSG_EVENT_GSP_POST_NOCAT_RECORD => Ok(MsgFunction::GspPostNoCat),
bindings::NV_VGPU_MSG_EVENT_GSP_RUN_CPU_SEQUENCER => {
Ok(MsgFunction::GspRunCpuSequencer)
}
- bindings::NV_VGPU_MSG_EVENT_POST_EVENT => Ok(MsgFunction::PostEvent),
- bindings::NV_VGPU_MSG_EVENT_RC_TRIGGERED => Ok(MsgFunction::RcTriggered),
bindings::NV_VGPU_MSG_EVENT_MMU_FAULT_QUEUED => Ok(MsgFunction::MmuFaultQueued),
bindings::NV_VGPU_MSG_EVENT_OS_ERROR_LOG => Ok(MsgFunction::OsErrorLog),
- bindings::NV_VGPU_MSG_EVENT_GSP_POST_NOCAT_RECORD => Ok(MsgFunction::GspPostNoCat),
- bindings::NV_VGPU_MSG_EVENT_GSP_LOCKDOWN_NOTICE => Ok(MsgFunction::GspLockdownNotice),
+ bindings::NV_VGPU_MSG_EVENT_POST_EVENT => Ok(MsgFunction::PostEvent),
+ bindings::NV_VGPU_MSG_EVENT_RC_TRIGGERED => Ok(MsgFunction::RcTriggered),
bindings::NV_VGPU_MSG_EVENT_UCODE_LIBOS_PRINT => Ok(MsgFunction::UcodeLibOsPrint),
_ => Err(EINVAL),
}
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 2/9] gpu: nova-core: gsp: add mechanism to wait for space on command queue
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
2026-03-06 7:21 ` [PATCH v6 1/9] gpu: nova-core: gsp: sort `MsgFunction` variants alphabetically Eliot Courtney
@ 2026-03-06 7:21 ` Eliot Courtney
2026-03-06 7:22 ` [PATCH v6 3/9] rust: add EMSGSIZE error code Eliot Courtney
` (7 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:21 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
Add a timeout to `allocate_command` which waits for space on the GSP
command queue. It uses a similar timeout to nouveau.
This lets `send_command` wait for space to free up in the command queue.
This is required to support continuation records which can fill up the
queue.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/cmdq.rs | 42 ++++++++++++++++++++++++++++-----------
1 file changed, 30 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 87dbbd6d1be9..12849bc057f2 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -250,6 +250,19 @@ fn new(dev: &device::Device<device::Bound>) -> Result<Self> {
}
}
+ /// Returns the size of the region of the CPU message queue that the driver is currently allowed
+ /// to write to, in bytes.
+ fn driver_write_area_size(&self) -> usize {
+ let tx = self.cpu_write_ptr();
+ let rx = self.gsp_read_ptr();
+
+ // `rx` and `tx` are both in `0..MSGQ_NUM_PAGES` per the invariants of `gsp_read_ptr` and
+ // `cpu_write_ptr`. The minimum value case is where `rx == 0` and `tx == MSGQ_NUM_PAGES -
+ // 1`, which gives `0 + MSGQ_NUM_PAGES - (MSGQ_NUM_PAGES - 1) - 1 == 0`.
+ let slots = (rx + MSGQ_NUM_PAGES - tx - 1) % MSGQ_NUM_PAGES;
+ num::u32_as_usize(slots) * GSP_PAGE_SIZE
+ }
+
/// Returns the region of the GSP message queue that the driver is currently allowed to read
/// from.
///
@@ -281,15 +294,22 @@ fn new(dev: &device::Device<device::Bound>) -> Result<Self> {
}
/// Allocates a region on the command queue that is large enough to send a command of `size`
- /// bytes.
+ /// bytes, waiting for space to become available based on the provided timeout.
///
/// This returns a [`GspCommand`] ready to be written to by the caller.
///
/// # Errors
///
- /// - `EAGAIN` if the driver area is too small to hold the requested command.
+ /// - `ETIMEDOUT` if space does not become available within the timeout.
/// - `EIO` if the command header is not properly aligned.
- fn allocate_command(&mut self, size: usize) -> Result<GspCommand<'_>> {
+ fn allocate_command(&mut self, size: usize, timeout: Delta) -> Result<GspCommand<'_>> {
+ read_poll_timeout(
+ || Ok(self.driver_write_area_size()),
+ |available_bytes| *available_bytes >= size_of::<GspMsgElement>() + size,
+ Delta::from_micros(1),
+ timeout,
+ )?;
+
// Get the current writable area as an array of bytes.
let (slice_1, slice_2) = {
let (slice_1, slice_2) = self.driver_write_area();
@@ -298,13 +318,6 @@ fn allocate_command(&mut self, size: usize) -> Result<GspCommand<'_>> {
(slice_1.as_flattened_mut(), slice_2.as_flattened_mut())
};
- // If the GSP is still processing previous messages the shared region
- // may be full in which case we will have to retry once the GSP has
- // processed the existing commands.
- if size_of::<GspMsgElement>() + size > slice_1.len() + slice_2.len() {
- return Err(EAGAIN);
- }
-
// Extract area for the `GspMsgElement`.
let (header, slice_1) = GspMsgElement::from_bytes_mut_prefix(slice_1).ok_or(EIO)?;
@@ -462,6 +475,9 @@ impl Cmdq {
/// Number of page table entries for the GSP shared region.
pub(crate) const NUM_PTES: usize = size_of::<GspMem>() >> GSP_PAGE_SHIFT;
+ /// Timeout for waiting for space on the command queue.
+ const ALLOCATE_TIMEOUT: Delta = Delta::from_secs(1);
+
/// Creates a new command queue for `dev`.
pub(crate) fn new(dev: &device::Device<device::Bound>) -> Result<Cmdq> {
let gsp_mem = DmaGspMem::new(dev)?;
@@ -497,7 +513,7 @@ fn notify_gsp(bar: &Bar0) {
///
/// # Errors
///
- /// - `EAGAIN` if there was not enough space in the command queue to send the command.
+ /// - `ETIMEDOUT` if space does not become available within the timeout.
/// - `EIO` if the variable payload requested by the command has not been entirely
/// written to by its [`CommandToGsp::init_variable_payload`] method.
///
@@ -509,7 +525,9 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
Error: From<M::InitError>,
{
let command_size = size_of::<M::Command>() + command.variable_payload_len();
- let dst = self.gsp_mem.allocate_command(command_size)?;
+ let dst = self
+ .gsp_mem
+ .allocate_command(command_size, Self::ALLOCATE_TIMEOUT)?;
// Extract area for the command itself.
let (cmd, payload_1) = M::Command::from_bytes_mut_prefix(dst.contents.0).ok_or(EIO)?;
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 3/9] rust: add EMSGSIZE error code
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
2026-03-06 7:21 ` [PATCH v6 1/9] gpu: nova-core: gsp: sort `MsgFunction` variants alphabetically Eliot Courtney
2026-03-06 7:21 ` [PATCH v6 2/9] gpu: nova-core: gsp: add mechanism to wait for space on command queue Eliot Courtney
@ 2026-03-06 7:22 ` Eliot Courtney
2026-03-06 7:22 ` [PATCH v6 4/9] gpu: nova-core: gsp: add checking oversized commands Eliot Courtney
` (6 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:22 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
Add the EMSGSIZE error code, which indicates that a message is too
long.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
rust/kernel/error.rs | 1 +
1 file changed, 1 insertion(+)
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 258b12afdcba..10fcf1f0404d 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -67,6 +67,7 @@ macro_rules! declare_err {
declare_err!(EDOM, "Math argument out of domain of func.");
declare_err!(ERANGE, "Math result not representable.");
declare_err!(EOVERFLOW, "Value too large for defined data type.");
+ declare_err!(EMSGSIZE, "Message too long.");
declare_err!(ETIMEDOUT, "Connection timed out.");
declare_err!(ERESTARTSYS, "Restart the system call.");
declare_err!(ERESTARTNOINTR, "System call was interrupted by a signal and will be restarted.");
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 4/9] gpu: nova-core: gsp: add checking oversized commands
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
` (2 preceding siblings ...)
2026-03-06 7:22 ` [PATCH v6 3/9] rust: add EMSGSIZE error code Eliot Courtney
@ 2026-03-06 7:22 ` Eliot Courtney
2026-03-06 7:22 ` [PATCH v6 5/9] gpu: nova-core: gsp: clarify invariant on command queue Eliot Courtney
` (5 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:22 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
The limit is 16 pages for a single command sent to the GSP. Return an
error if `allocate_command` is called with a too large size.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/cmdq.rs | 7 ++++++-
drivers/gpu/nova-core/gsp/fw.rs | 4 ++++
drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs | 1 +
3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 12849bc057f2..8b970523d789 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -32,7 +32,8 @@
GspMsgElement,
MsgFunction,
MsgqRxHeader,
- MsgqTxHeader, //
+ MsgqTxHeader,
+ GSP_MSG_QUEUE_ELEMENT_SIZE_MAX, //
},
PteArray,
GSP_PAGE_SHIFT,
@@ -300,9 +301,13 @@ fn driver_write_area_size(&self) -> usize {
///
/// # Errors
///
+ /// - `EMSGSIZE` if the command is larger than [`GSP_MSG_QUEUE_ELEMENT_SIZE_MAX`].
/// - `ETIMEDOUT` if space does not become available within the timeout.
/// - `EIO` if the command header is not properly aligned.
fn allocate_command(&mut self, size: usize, timeout: Delta) -> Result<GspCommand<'_>> {
+ if size_of::<GspMsgElement>() + size > GSP_MSG_QUEUE_ELEMENT_SIZE_MAX {
+ return Err(EMSGSIZE);
+ }
read_poll_timeout(
|| Ok(self.driver_write_area_size()),
|available_bytes| *available_bytes >= size_of::<GspMsgElement>() + size,
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 4b998485360b..6005362450cb 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -39,6 +39,10 @@
},
};
+/// Maximum size of a single GSP message queue element in bytes.
+pub(crate) const GSP_MSG_QUEUE_ELEMENT_SIZE_MAX: usize =
+ num::u32_as_usize(bindings::GSP_MSG_QUEUE_ELEMENT_SIZE_MAX);
+
/// Empty type to group methods related to heap parameters for running the GSP firmware.
enum GspFwHeapParams {}
diff --git a/drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs b/drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs
index 6d25fe0bffa9..334e8be5fde8 100644
--- a/drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs
+++ b/drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs
@@ -43,6 +43,7 @@ fn fmt(&self, fmt: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
pub const GSP_FW_WPR_META_REVISION: u32 = 1;
pub const GSP_FW_WPR_META_MAGIC: i64 = -2577556379034558285;
pub const REGISTRY_TABLE_ENTRY_TYPE_DWORD: u32 = 1;
+pub const GSP_MSG_QUEUE_ELEMENT_SIZE_MAX: u32 = 65536;
pub type __u8 = ffi::c_uchar;
pub type __u16 = ffi::c_ushort;
pub type __u32 = ffi::c_uint;
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 5/9] gpu: nova-core: gsp: clarify invariant on command queue
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
` (3 preceding siblings ...)
2026-03-06 7:22 ` [PATCH v6 4/9] gpu: nova-core: gsp: add checking oversized commands Eliot Courtney
@ 2026-03-06 7:22 ` Eliot Courtney
2026-03-06 7:22 ` [PATCH v6 6/9] gpu: nova-core: gsp: unconditionally call variable payload handling Eliot Courtney
` (4 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:22 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
Clarify why using only the first returned slice from allocate_command
for the message headers is okay.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/cmdq.rs | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 8b970523d789..806b1e02715e 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -534,7 +534,9 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
.gsp_mem
.allocate_command(command_size, Self::ALLOCATE_TIMEOUT)?;
- // Extract area for the command itself.
+ // Extract area for the command itself. The GSP message header and the command header
+ // together are guaranteed to fit entirely into a single page, so it's ok to only look
+ // at `dst.contents.0` here.
let (cmd, payload_1) = M::Command::from_bytes_mut_prefix(dst.contents.0).ok_or(EIO)?;
// Fill the header and command in-place.
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 6/9] gpu: nova-core: gsp: unconditionally call variable payload handling
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
` (4 preceding siblings ...)
2026-03-06 7:22 ` [PATCH v6 5/9] gpu: nova-core: gsp: clarify invariant on command queue Eliot Courtney
@ 2026-03-06 7:22 ` Eliot Courtney
2026-03-06 7:22 ` [PATCH v6 7/9] gpu: nova-core: gsp: add `size` helper to `CommandToGsp` Eliot Courtney
` (3 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:22 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
Unconditionally call the variable length payload code, which is a no-op
if there is no such payload but could defensively catch some coding
errors by e.g. checking that the allocated size is completely filled.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/cmdq.rs | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 806b1e02715e..b41a866e24da 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -548,16 +548,14 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
command.init().__init(core::ptr::from_mut(cmd))?;
}
- // Fill the variable-length payload.
- if command_size > size_of::<M::Command>() {
- let mut sbuffer =
- SBufferIter::new_writer([&mut payload_1[..], &mut dst.contents.1[..]]);
- command.init_variable_payload(&mut sbuffer)?;
+ // Fill the variable-length payload, which may be empty.
+ let mut sbuffer = SBufferIter::new_writer([&mut payload_1[..], &mut dst.contents.1[..]]);
+ command.init_variable_payload(&mut sbuffer)?;
- if !sbuffer.is_empty() {
- return Err(EIO);
- }
+ if !sbuffer.is_empty() {
+ return Err(EIO);
}
+ drop(sbuffer);
// Compute checksum now that the whole message is ready.
dst.header
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 7/9] gpu: nova-core: gsp: add `size` helper to `CommandToGsp`
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
` (5 preceding siblings ...)
2026-03-06 7:22 ` [PATCH v6 6/9] gpu: nova-core: gsp: unconditionally call variable payload handling Eliot Courtney
@ 2026-03-06 7:22 ` Eliot Courtney
2026-03-06 7:22 ` [PATCH v6 8/9] gpu: nova-core: gsp: support large RPCs via continuation record Eliot Courtney
` (2 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:22 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
Add a default method to `CommandToGsp` which computes the size of a
command.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/cmdq.rs | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index b41a866e24da..861f5666fe7f 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -94,6 +94,12 @@ fn init_variable_payload(
) -> Result {
Ok(())
}
+
+ /// Total size of the command (including its variable-length payload) without the
+ /// [`GspMsgElement`] header.
+ fn size(&self) -> usize {
+ size_of::<Self::Command>() + self.variable_payload_len()
+ }
}
/// Trait representing messages received from the GSP.
@@ -529,10 +535,10 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
// This allows all error types, including `Infallible`, to be used for `M::InitError`.
Error: From<M::InitError>,
{
- let command_size = size_of::<M::Command>() + command.variable_payload_len();
+ let size_in_bytes = command.size();
let dst = self
.gsp_mem
- .allocate_command(command_size, Self::ALLOCATE_TIMEOUT)?;
+ .allocate_command(size_in_bytes, Self::ALLOCATE_TIMEOUT)?;
// Extract area for the command itself. The GSP message header and the command header
// together are guaranteed to fit entirely into a single page, so it's ok to only look
@@ -540,7 +546,7 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
let (cmd, payload_1) = M::Command::from_bytes_mut_prefix(dst.contents.0).ok_or(EIO)?;
// Fill the header and command in-place.
- let msg_element = GspMsgElement::init(self.seq, command_size, M::FUNCTION);
+ let msg_element = GspMsgElement::init(self.seq, size_in_bytes, M::FUNCTION);
// SAFETY: `msg_header` and `cmd` are valid references, and not touched if the initializer
// fails.
unsafe {
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 8/9] gpu: nova-core: gsp: support large RPCs via continuation record
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
` (6 preceding siblings ...)
2026-03-06 7:22 ` [PATCH v6 7/9] gpu: nova-core: gsp: add `size` helper to `CommandToGsp` Eliot Courtney
@ 2026-03-06 7:22 ` Eliot Courtney
2026-03-06 7:22 ` [PATCH v6 9/9] gpu: nova-core: gsp: add tests for continuation records Eliot Courtney
2026-03-10 7:44 ` [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Alexandre Courbot
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:22 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
Splits large RPCs if necessary and sends the remaining parts using
continuation records. RPCs that do not need continuation records
continue to write directly into the command buffer. Ones that do write
into a staging buffer first, so there is one copy.
Continuation record for receive is not necessary to support at the
moment because those replies do not need to be read and are currently
drained by retrying `receive_msg` on `ERANGE`.
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/cmdq.rs | 42 ++++++-
drivers/gpu/nova-core/gsp/cmdq/continuation.rs | 163 +++++++++++++++++++++++++
drivers/gpu/nova-core/gsp/fw.rs | 4 +
3 files changed, 207 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 861f5666fe7f..e0b096546d23 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -1,5 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
+mod continuation;
+
use core::{
mem,
sync::atomic::{
@@ -25,6 +27,11 @@
},
};
+use continuation::{
+ ContinuationRecord,
+ SplitState, //
+};
+
use crate::{
driver::Bar0,
gsp::{
@@ -520,7 +527,7 @@ fn notify_gsp(bar: &Bar0) {
.write(bar);
}
- /// Sends `command` to the GSP.
+ /// Sends `command` to the GSP, without splitting it.
///
/// # Errors
///
@@ -529,7 +536,7 @@ fn notify_gsp(bar: &Bar0) {
/// written to by its [`CommandToGsp::init_variable_payload`] method.
///
/// Error codes returned by the command initializers are propagated as-is.
- pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
+ fn send_single_command<M>(&mut self, bar: &Bar0, command: M) -> Result
where
M: CommandToGsp,
// This allows all error types, including `Infallible`, to be used for `M::InitError`.
@@ -588,6 +595,37 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
Ok(())
}
+ /// Sends `command` to the GSP.
+ ///
+ /// The command may be split into multiple messages if it is large.
+ ///
+ /// # Errors
+ ///
+ /// - `ETIMEDOUT` if space does not become available within the timeout.
+ /// - `EIO` if the variable payload requested by the command has not been entirely
+ /// written to by its [`CommandToGsp::init_variable_payload`] method.
+ ///
+ /// Error codes returned by the command initializers are propagated as-is.
+ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
+ where
+ M: CommandToGsp,
+ Error: From<M::InitError>,
+ {
+ match SplitState::new(command)? {
+ SplitState::Single(command) => self.send_single_command(bar, command),
+ SplitState::Split(command, mut continuations) => {
+ self.send_single_command(bar, command)?;
+
+ while let Some(continuation) = continuations.next() {
+ // Turbofish needed because the compiler cannot infer M here.
+ self.send_single_command::<ContinuationRecord<'_>>(bar, continuation)?;
+ }
+
+ Ok(())
+ }
+ }
+ }
+
/// Wait for a message to become available on the message queue.
///
/// This works purely at the transport layer and does not interpret or validate the message
diff --git a/drivers/gpu/nova-core/gsp/cmdq/continuation.rs b/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
new file mode 100644
index 000000000000..67b3e03fd8ea
--- /dev/null
+++ b/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Support for splitting large GSP commands across continuation records.
+
+use core::convert::Infallible;
+
+use kernel::prelude::*;
+
+use super::CommandToGsp;
+
+use crate::{
+ gsp::fw::{
+ GspMsgElement,
+ MsgFunction,
+ GSP_MSG_QUEUE_ELEMENT_SIZE_MAX, //
+ },
+ sbuffer::SBufferIter,
+};
+
+/// Maximum command size that fits in a single queue element.
+const MAX_CMD_SIZE: usize = GSP_MSG_QUEUE_ELEMENT_SIZE_MAX - size_of::<GspMsgElement>();
+
+/// Acts as an iterator over the continuation records for a split command.
+pub(super) struct ContinuationRecords {
+ payload: KVVec<u8>,
+ offset: usize,
+}
+
+impl ContinuationRecords {
+ /// Creates a new iterator over continuation records for the given payload.
+ fn new(payload: KVVec<u8>) -> Self {
+ Self { payload, offset: 0 }
+ }
+
+ /// Returns the next continuation record, or [`None`] if there are no more.
+ pub(super) fn next(&mut self) -> Option<ContinuationRecord<'_>> {
+ let remaining = self.payload.len() - self.offset;
+
+ if remaining > 0 {
+ let chunk_size = remaining.min(MAX_CMD_SIZE);
+ let record =
+ ContinuationRecord::new(&self.payload[self.offset..(self.offset + chunk_size)]);
+ self.offset += chunk_size;
+ Some(record)
+ } else {
+ None
+ }
+ }
+}
+
+/// The [`ContinuationRecord`] command.
+pub(super) struct ContinuationRecord<'a> {
+ data: &'a [u8],
+}
+
+impl<'a> ContinuationRecord<'a> {
+ /// Creates a new [`ContinuationRecord`] command with the given data.
+ fn new(data: &'a [u8]) -> Self {
+ Self { data }
+ }
+}
+
+impl<'a> CommandToGsp for ContinuationRecord<'a> {
+ const FUNCTION: MsgFunction = MsgFunction::ContinuationRecord;
+ type Command = ();
+ type InitError = Infallible;
+
+ fn init(&self) -> impl Init<Self::Command, Self::InitError> {
+ <()>::init_zeroed()
+ }
+
+ fn variable_payload_len(&self) -> usize {
+ self.data.len()
+ }
+
+ fn init_variable_payload(
+ &self,
+ dst: &mut SBufferIter<core::array::IntoIter<&mut [u8], 2>>,
+ ) -> Result {
+ dst.write_all(self.data)
+ }
+}
+
+/// Whether a command needs to be split across continuation records or not.
+pub(super) enum SplitState<C: CommandToGsp> {
+ /// A command that fits in a single queue element.
+ Single(C),
+ /// A command split across continuation records.
+ Split(SplitCommand<C>, ContinuationRecords),
+}
+
+impl<C: CommandToGsp> SplitState<C> {
+ /// Maximum variable payload size that fits in the first command alongside the command header.
+ const MAX_FIRST_PAYLOAD: usize = MAX_CMD_SIZE - size_of::<C::Command>();
+
+ /// Creates a new [`SplitState`] for the given command.
+ ///
+ /// If the command is too large, it will be split into a main command and some number of
+ /// continuation records.
+ pub(super) fn new(command: C) -> Result<Self> {
+ let payload_len = command.variable_payload_len();
+
+ if command.size() > MAX_CMD_SIZE {
+ let mut command_payload =
+ KVVec::<u8>::from_elem(0u8, payload_len.min(Self::MAX_FIRST_PAYLOAD), GFP_KERNEL)?;
+ let mut continuation_payload =
+ KVVec::<u8>::from_elem(0u8, payload_len - command_payload.len(), GFP_KERNEL)?;
+ let mut sbuffer = SBufferIter::new_writer([
+ command_payload.as_mut_slice(),
+ continuation_payload.as_mut_slice(),
+ ]);
+
+ command.init_variable_payload(&mut sbuffer)?;
+ if !sbuffer.is_empty() {
+ return Err(EIO);
+ }
+ drop(sbuffer);
+
+ Ok(Self::Split(
+ SplitCommand::new(command, command_payload),
+ ContinuationRecords::new(continuation_payload),
+ ))
+ } else {
+ Ok(Self::Single(command))
+ }
+ }
+}
+
+/// A command that has been truncated to maximum accepted length of the command queue.
+///
+/// The remainder of its payload is expected to be sent using [`ContinuationRecords`].
+pub(super) struct SplitCommand<C: CommandToGsp> {
+ command: C,
+ payload: KVVec<u8>,
+}
+
+impl<C: CommandToGsp> SplitCommand<C> {
+ /// Creates a new [`SplitCommand`] wrapping `command` with the given truncated payload.
+ fn new(command: C, payload: KVVec<u8>) -> Self {
+ Self { command, payload }
+ }
+}
+
+impl<C: CommandToGsp> CommandToGsp for SplitCommand<C> {
+ const FUNCTION: MsgFunction = C::FUNCTION;
+ type Command = C::Command;
+ type InitError = C::InitError;
+
+ fn init(&self) -> impl Init<Self::Command, Self::InitError> {
+ self.command.init()
+ }
+
+ fn variable_payload_len(&self) -> usize {
+ self.payload.len()
+ }
+
+ fn init_variable_payload(
+ &self,
+ dst: &mut SBufferIter<core::array::IntoIter<&mut [u8], 2>>,
+ ) -> Result {
+ dst.write_all(&self.payload)
+ }
+}
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 6005362450cb..25fca1f6db2c 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -202,6 +202,7 @@ pub(crate) enum MsgFunction {
AllocObject = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_OBJECT,
AllocRoot = bindings::NV_VGPU_MSG_FUNCTION_ALLOC_ROOT,
BindCtxDma = bindings::NV_VGPU_MSG_FUNCTION_BIND_CTX_DMA,
+ ContinuationRecord = bindings::NV_VGPU_MSG_FUNCTION_CONTINUATION_RECORD,
Free = bindings::NV_VGPU_MSG_FUNCTION_FREE,
GetGspStaticInfo = bindings::NV_VGPU_MSG_FUNCTION_GET_GSP_STATIC_INFO,
GetStaticInfo = bindings::NV_VGPU_MSG_FUNCTION_GET_STATIC_INFO,
@@ -239,6 +240,9 @@ fn try_from(value: u32) -> Result<MsgFunction> {
bindings::NV_VGPU_MSG_FUNCTION_ALLOC_OBJECT => Ok(MsgFunction::AllocObject),
bindings::NV_VGPU_MSG_FUNCTION_ALLOC_ROOT => Ok(MsgFunction::AllocRoot),
bindings::NV_VGPU_MSG_FUNCTION_BIND_CTX_DMA => Ok(MsgFunction::BindCtxDma),
+ bindings::NV_VGPU_MSG_FUNCTION_CONTINUATION_RECORD => {
+ Ok(MsgFunction::ContinuationRecord)
+ }
bindings::NV_VGPU_MSG_FUNCTION_FREE => Ok(MsgFunction::Free),
bindings::NV_VGPU_MSG_FUNCTION_GET_GSP_STATIC_INFO => Ok(MsgFunction::GetGspStaticInfo),
bindings::NV_VGPU_MSG_FUNCTION_GET_STATIC_INFO => Ok(MsgFunction::GetStaticInfo),
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v6 9/9] gpu: nova-core: gsp: add tests for continuation records
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
` (7 preceding siblings ...)
2026-03-06 7:22 ` [PATCH v6 8/9] gpu: nova-core: gsp: support large RPCs via continuation record Eliot Courtney
@ 2026-03-06 7:22 ` Eliot Courtney
2026-03-10 7:44 ` [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Alexandre Courbot
9 siblings, 0 replies; 11+ messages in thread
From: Eliot Courtney @ 2026-03-06 7:22 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, Alexandre Courbot, David Airlie,
Simona Vetter, Miguel Ojeda, Boqun Feng, Gary Guo,
Björn Roy Baron, Benno Lossin, Andreas Hindborg,
Trevor Gross
Cc: Zhi Wang, John Hubbard, Alistair Popple, Joel Fernandes,
Timur Tabi, nouveau, dri-devel, linux-kernel, rust-for-linux,
Eliot Courtney
Add tests for continuation record splitting. They cover boundary
conditions at the split points to make sure the right number of
continuation records are made. They also check that the data
concatenated is correct.
Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/gsp/cmdq/continuation.rs | 138 +++++++++++++++++++++++++
1 file changed, 138 insertions(+)
diff --git a/drivers/gpu/nova-core/gsp/cmdq/continuation.rs b/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
index 67b3e03fd8ea..2aa17caac2e0 100644
--- a/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
@@ -161,3 +161,141 @@ fn init_variable_payload(
dst.write_all(&self.payload)
}
}
+
+#[kunit_tests(nova_core_gsp_continuation)]
+mod tests {
+ use super::*;
+
+ use kernel::transmute::{
+ AsBytes,
+ FromBytes, //
+ };
+
+ /// Non-zero-sized command header for testing.
+ #[repr(C)]
+ #[derive(Clone, Copy, Zeroable)]
+ struct TestHeader([u8; 64]);
+
+ // SAFETY: `TestHeader` is a plain array of bytes for which all bit patterns are valid.
+ unsafe impl FromBytes for TestHeader {}
+
+ // SAFETY: `TestHeader` is a plain array of bytes for which all bit patterns are valid.
+ unsafe impl AsBytes for TestHeader {}
+
+ struct TestPayload {
+ data: KVVec<u8>,
+ }
+
+ impl TestPayload {
+ fn generate_pattern(len: usize) -> Result<KVVec<u8>> {
+ let mut data = KVVec::with_capacity(len, GFP_KERNEL)?;
+ for i in 0..len {
+ // Mix in higher bits so the pattern does not repeat every 256 bytes.
+ data.push((i ^ (i >> 8)) as u8, GFP_KERNEL)?;
+ }
+ Ok(data)
+ }
+
+ fn new(len: usize) -> Result<Self> {
+ Ok(Self {
+ data: Self::generate_pattern(len)?,
+ })
+ }
+ }
+
+ impl CommandToGsp for TestPayload {
+ const FUNCTION: MsgFunction = MsgFunction::Nop;
+ type Command = TestHeader;
+ type InitError = Infallible;
+
+ fn init(&self) -> impl Init<Self::Command, Self::InitError> {
+ TestHeader::init_zeroed()
+ }
+
+ fn variable_payload_len(&self) -> usize {
+ self.data.len()
+ }
+
+ fn init_variable_payload(
+ &self,
+ dst: &mut SBufferIter<core::array::IntoIter<&mut [u8], 2>>,
+ ) -> Result {
+ dst.write_all(self.data.as_slice())
+ }
+ }
+
+ /// Maximum variable payload size that fits in the first command alongside the header.
+ const MAX_FIRST_PAYLOAD: usize = SplitState::<TestPayload>::MAX_FIRST_PAYLOAD;
+
+ fn read_payload(cmd: impl CommandToGsp) -> Result<KVVec<u8>> {
+ let len = cmd.variable_payload_len();
+ let mut buf = KVVec::from_elem(0u8, len, GFP_KERNEL)?;
+ let mut sbuf = SBufferIter::new_writer([buf.as_mut_slice(), &mut []]);
+ cmd.init_variable_payload(&mut sbuf)?;
+ drop(sbuf);
+ Ok(buf)
+ }
+
+ struct SplitTest {
+ payload_size: usize,
+ num_continuations: usize,
+ }
+
+ fn check_split(t: SplitTest) -> Result {
+ let payload = TestPayload::new(t.payload_size)?;
+ let mut num_continuations = 0;
+
+ let buf = match SplitState::new(payload)? {
+ SplitState::Single(cmd) => read_payload(cmd)?,
+ SplitState::Split(cmd, mut continuations) => {
+ let mut buf = read_payload(cmd)?;
+ assert!(size_of::<TestHeader>() + buf.len() <= MAX_CMD_SIZE);
+
+ while let Some(cont) = continuations.next() {
+ let payload = read_payload(cont)?;
+ assert!(payload.len() <= MAX_CMD_SIZE);
+ buf.extend_from_slice(&payload, GFP_KERNEL)?;
+ num_continuations += 1;
+ }
+
+ buf
+ }
+ };
+
+ assert_eq!(num_continuations, t.num_continuations);
+ assert_eq!(
+ buf.as_slice(),
+ TestPayload::generate_pattern(t.payload_size)?.as_slice()
+ );
+ Ok(())
+ }
+
+ #[test]
+ fn split_command() -> Result {
+ check_split(SplitTest {
+ payload_size: 0,
+ num_continuations: 0,
+ })?;
+ check_split(SplitTest {
+ payload_size: MAX_FIRST_PAYLOAD,
+ num_continuations: 0,
+ })?;
+ check_split(SplitTest {
+ payload_size: MAX_FIRST_PAYLOAD + 1,
+ num_continuations: 1,
+ })?;
+ check_split(SplitTest {
+ payload_size: MAX_FIRST_PAYLOAD + MAX_CMD_SIZE,
+ num_continuations: 1,
+ })?;
+ check_split(SplitTest {
+ payload_size: MAX_FIRST_PAYLOAD + MAX_CMD_SIZE + 1,
+ num_continuations: 2,
+ })?;
+ check_split(SplitTest {
+ payload_size: MAX_FIRST_PAYLOAD + MAX_CMD_SIZE * 3 + MAX_CMD_SIZE / 2,
+ num_continuations: 4,
+ })?;
+ Ok(())
+ }
+}
--
2.53.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support
2026-03-06 7:21 [PATCH v6 0/9] gpu: nova-core: gsp: add continuation record support Eliot Courtney
` (8 preceding siblings ...)
2026-03-06 7:22 ` [PATCH v6 9/9] gpu: nova-core: gsp: add tests for continuation records Eliot Courtney
@ 2026-03-10 7:44 ` Alexandre Courbot
9 siblings, 0 replies; 11+ messages in thread
From: Alexandre Courbot @ 2026-03-10 7:44 UTC (permalink / raw)
To: Eliot Courtney
Cc: Danilo Krummrich, Alice Ryhl, David Airlie, Simona Vetter,
Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Trevor Gross, Zhi Wang,
John Hubbard, Alistair Popple, Joel Fernandes, Timur Tabi,
nouveau, dri-devel, linux-kernel, rust-for-linux
On Fri Mar 6, 2026 at 4:21 PM JST, Eliot Courtney wrote:
> GSP commands over 16 pages need to be sent using "continuation records"
> which essentially means splitting the payload over multiple commands.
>
> This series adds a command type `ContinuationRecord` which just writes
> its header and whatever payload it is given. It also adds types
> `SplitState` and `SplitCommand` which support splitting a large RPC
> into smaller ones while transparently letting regular sized RPCs be sent
> without extra copies.
>
> The send pathway uses `SplitState` to send all commands, but if
> the command fits into 16 pages, it still writes directly into the
> command queue. If it is larger than 16 pages and needs continuation
> records, it writes into a staging buffer, so there is one copy.
>
> Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
Merged to drm-rust-next, thanks!
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