* [PATCH 1/2] gpu: nova-core: use kernel lossless integer conversion module
2026-08-28 5:33 [PATCH 0/2] gpu: nova-core: complete conversion to kernel `num` module Alexandre Courbot
@ 2026-08-28 5:33 ` Alexandre Courbot
2026-08-28 5:43 ` sashiko-bot
2026-08-28 12:09 ` Danilo Krummrich
2026-08-28 5:33 ` [PATCH 2/2] gpu: nova-core: use FromSafeCast wherever possible Alexandre Courbot
1 sibling, 2 replies; 9+ messages in thread
From: Alexandre Courbot @ 2026-08-28 5:33 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, David Airlie, Simona Vetter
Cc: John Hubbard, Alistair Popple, Timur Tabi, Eliot Courtney,
Zhi Wang, nova-gpu, dri-devel, rust-for-linux, linux-kernel,
Alexandre Courbot
The `kernel` crate now features a replacement for our lossless integer
conversion routines. Switch to the kernel version and remove our own.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
---
drivers/gpu/nova-core/falcon.rs | 12 +-
drivers/gpu/nova-core/falcon/fsp.rs | 4 +-
drivers/gpu/nova-core/fb.rs | 2 +-
drivers/gpu/nova-core/fb/hal/gb100.rs | 6 +-
drivers/gpu/nova-core/firmware.rs | 4 +-
drivers/gpu/nova-core/firmware/booter.rs | 4 +-
drivers/gpu/nova-core/firmware/fwsec.rs | 2 +-
drivers/gpu/nova-core/firmware/fwsec/bootloader.rs | 4 +-
drivers/gpu/nova-core/firmware/gsp.rs | 9 +-
drivers/gpu/nova-core/firmware/tlv.rs | 11 +-
drivers/gpu/nova-core/fsp.rs | 8 +-
drivers/gpu/nova-core/gsp.rs | 4 +-
drivers/gpu/nova-core/gsp/cmdq.rs | 22 +--
drivers/gpu/nova-core/gsp/fw.rs | 42 ++--
drivers/gpu/nova-core/gsp/fw/commands.rs | 4 +-
drivers/gpu/nova-core/gsp/sequencer.rs | 2 +-
drivers/gpu/nova-core/mctp.rs | 8 +-
drivers/gpu/nova-core/num.rs | 211 ---------------------
drivers/gpu/nova-core/vbios.rs | 2 +-
19 files changed, 78 insertions(+), 283 deletions(-)
diff --git a/drivers/gpu/nova-core/falcon.rs b/drivers/gpu/nova-core/falcon.rs
index 65cb12d26e2b..dfe4d2e6f82e 100644
--- a/drivers/gpu/nova-core/falcon.rs
+++ b/drivers/gpu/nova-core/falcon.rs
@@ -20,6 +20,10 @@
},
Io,
},
+ num::casts::{
+ self,
+ FromSafeCast, //
+ },
prelude::*,
time::Delta,
};
@@ -29,11 +33,7 @@
driver::Bar0,
falcon::hal::LoadMethod,
gpu::Chipset,
- num::{
- self,
- FromSafeCast, //
- },
- regs,
+ regs, //
};
pub(crate) mod fsp;
@@ -510,7 +510,7 @@ fn dma_wr(
target_mem: FalconMem,
load_offsets: FalconDmaLoadTarget,
) -> Result {
- const DMA_LEN: u32 = num::usize_into_u32::<{ MEM_BLOCK_ALIGNMENT }>();
+ const DMA_LEN: u32 = casts::usize_into_u32::<{ MEM_BLOCK_ALIGNMENT }>();
// DMA transfers can only be done in units of 256 bytes. Compute how many such transfers we
// need to perform.
diff --git a/drivers/gpu/nova-core/falcon/fsp.rs b/drivers/gpu/nova-core/falcon/fsp.rs
index 0437180b8829..2470ac511c98 100644
--- a/drivers/gpu/nova-core/falcon/fsp.rs
+++ b/drivers/gpu/nova-core/falcon/fsp.rs
@@ -16,6 +16,7 @@
},
Io, //
},
+ num::casts,
prelude::*,
sizes::SZ_1K,
time::Delta,
@@ -28,7 +29,6 @@
PFalcon2Base,
PFalconBase, //
},
- num,
regs, //
};
@@ -165,7 +165,7 @@ pub(crate) fn recv_msg(&mut self) -> Result<KVec<u8>> {
Delta::from_millis(10),
Delta::from_millis(FSP_MSG_TIMEOUT_MS),
)
- .map(num::u32_as_usize)?;
+ .map(casts::u32_as_usize)?;
// Don't blindly allocate more than the maximum we expect from FSP.
if msg_size > FSP_EMEM_CHANNEL_0_SIZE {
diff --git a/drivers/gpu/nova-core/fb.rs b/drivers/gpu/nova-core/fb.rs
index 1576399389b1..8d5d9480378f 100644
--- a/drivers/gpu/nova-core/fb.rs
+++ b/drivers/gpu/nova-core/fb.rs
@@ -10,6 +10,7 @@
dma::CoherentHandle,
fmt,
io::Io,
+ num::casts::FromSafeCast,
prelude::*,
ptr::{
Alignable,
@@ -23,7 +24,6 @@
firmware::gsp::GspFirmware,
gpu::Chipset,
gsp,
- num::FromSafeCast,
vgpu::VgpuState, //
};
diff --git a/drivers/gpu/nova-core/fb/hal/gb100.rs b/drivers/gpu/nova-core/fb/hal/gb100.rs
index d9e4d62ae632..a53d8b435dc2 100644
--- a/drivers/gpu/nova-core/fb/hal/gb100.rs
+++ b/drivers/gpu/nova-core/fb/hal/gb100.rs
@@ -11,7 +11,10 @@
},
Io, //
},
- num::Bounded,
+ num::{
+ casts::usize_into_u32,
+ Bounded, //
+ },
prelude::*,
ptr::{
const_align_up,
@@ -26,7 +29,6 @@
hal::FbHal,
regs, //
},
- num::usize_into_u32,
};
struct Gb100;
diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
index b49613a90bf0..19f13779bb30 100644
--- a/drivers/gpu/nova-core/firmware.rs
+++ b/drivers/gpu/nova-core/firmware.rs
@@ -9,6 +9,7 @@
use kernel::{
firmware,
+ num::casts::IntoSafeCast,
prelude::*, //
};
@@ -18,8 +19,7 @@
FalconFirmware, //
},
gpu,
- gsp::boot_firmware_files,
- num::IntoSafeCast, //
+ gsp::boot_firmware_files, //
};
pub(crate) mod booter;
diff --git a/drivers/gpu/nova-core/firmware/booter.rs b/drivers/gpu/nova-core/firmware/booter.rs
index dc071edba331..aa830455b7e7 100644
--- a/drivers/gpu/nova-core/firmware/booter.rs
+++ b/drivers/gpu/nova-core/firmware/booter.rs
@@ -10,6 +10,7 @@
use kernel::{
device,
dma::Coherent,
+ num::casts::IntoSafeCast,
prelude::*, //
};
@@ -32,8 +33,7 @@
Signed,
Unsigned, //
},
- gpu::Chipset,
- num::IntoSafeCast,
+ gpu::Chipset, //
};
/// Signature for Booter firmware. Their size is encoded into the header and not known a compile
diff --git a/drivers/gpu/nova-core/firmware/fwsec.rs b/drivers/gpu/nova-core/firmware/fwsec.rs
index 7a931f22f629..7f7ca3ba2298 100644
--- a/drivers/gpu/nova-core/firmware/fwsec.rs
+++ b/drivers/gpu/nova-core/firmware/fwsec.rs
@@ -19,6 +19,7 @@
self,
Device, //
},
+ num::casts::FromSafeCast,
prelude::*,
transmute::{
AsBytes,
@@ -42,7 +43,6 @@
Signed,
Unsigned, //
},
- num::FromSafeCast,
vbios::Vbios,
};
diff --git a/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs b/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
index ec4d92317a93..d1fb7d2d7480 100644
--- a/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
+++ b/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
@@ -13,6 +13,7 @@
},
dma::Coherent,
io::{register::WithBase, Io},
+ num::casts::FromSafeCast,
prelude::*,
ptr::{
Alignable,
@@ -45,8 +46,7 @@
},
},
gpu::Chipset,
- num::FromSafeCast, //
- regs,
+ regs, //
};
/// Structure used by the boot-loader to load the rest of the code.
diff --git a/drivers/gpu/nova-core/firmware/gsp.rs b/drivers/gpu/nova-core/firmware/gsp.rs
index e8f9491e84cc..e75ce6fe47d8 100644
--- a/drivers/gpu/nova-core/firmware/gsp.rs
+++ b/drivers/gpu/nova-core/firmware/gsp.rs
@@ -9,6 +9,10 @@
DmaAddress, //
},
firmware,
+ num::casts::{
+ arch::FromSafeCastArch,
+ FromSafeCast, //
+ },
prelude::*,
scatterlist::{
Owned,
@@ -26,8 +30,7 @@
},
},
gpu::Chipset,
- gsp::GSP_PAGE_SIZE,
- num::FromSafeCast,
+ gsp::GSP_PAGE_SIZE, //
};
/// GSP firmware with 3-level radix page tables for the GSP bootloader.
@@ -154,7 +157,7 @@ pub(crate) fn radix3_dma_address(&self) -> DmaAddress {
fn map_into_lvl(sg_table: &SGTable<Owned<VVec<u8>>>, mut dst: VVec<u8>) -> Result<VVec<u8>> {
for sg_entry in sg_table.iter() {
// Number of pages we need to map.
- let num_pages = usize::from_safe_cast(sg_entry.dma_len()).div_ceil(GSP_PAGE_SIZE);
+ let num_pages = usize::from_safe_cast_arch(sg_entry.dma_len()).div_ceil(GSP_PAGE_SIZE);
for i in 0..num_pages {
let entry = sg_entry.dma_address()
diff --git a/drivers/gpu/nova-core/firmware/tlv.rs b/drivers/gpu/nova-core/firmware/tlv.rs
index 7b879f13a61e..6653c10e3e0a 100644
--- a/drivers/gpu/nova-core/firmware/tlv.rs
+++ b/drivers/gpu/nova-core/firmware/tlv.rs
@@ -4,14 +4,15 @@
use kernel::{
device,
firmware,
+ num::casts::{
+ self,
+ IntoSafeCast, //
+ },
prelude::*,
str::CString, //
};
-use crate::{
- gpu,
- num::*, //
-};
+use crate::gpu;
/// Requests the GPU firmware TLV `name` suitable for `chipset`.
pub(crate) fn request_tlv(
@@ -51,7 +52,7 @@ fn parse(hdr: &[u8]) -> Option<Self> {
return None;
}
let len_arr = <[u8; 4]>::try_from(hdr.get(4..Self::SIZE)?).ok()?;
- let length = u32_as_usize(u32::from_le_bytes(len_arr));
+ let length = casts::u32_as_usize(u32::from_le_bytes(len_arr));
Some(Self { tag, length })
}
}
diff --git a/drivers/gpu/nova-core/fsp.rs b/drivers/gpu/nova-core/fsp.rs
index ab685fb4168f..b9ca298dc97f 100644
--- a/drivers/gpu/nova-core/fsp.rs
+++ b/drivers/gpu/nova-core/fsp.rs
@@ -11,7 +11,10 @@
device,
dma::Coherent,
io::poll::read_poll_timeout,
- num::TryIntoBounded,
+ num::{
+ casts,
+ TryIntoBounded, //
+ },
prelude::*,
ptr::{
Alignable,
@@ -47,7 +50,6 @@
NvdmHeader,
NvdmType, //
},
- num,
regs, //
};
@@ -285,7 +287,7 @@ fn new<'a>(
};
let version = hal.cot_version();
- let size = num::usize_into_u16::<{ core::mem::size_of::<NvdmPayloadCot>() }>();
+ let size = casts::usize_into_u16::<{ core::mem::size_of::<NvdmPayloadCot>() }>();
Ok(init!(Self {
header: FspMessageHeader::new(NvdmType::Cot),
diff --git a/drivers/gpu/nova-core/gsp.rs b/drivers/gpu/nova-core/gsp.rs
index 13f361406a6c..fc8648de84c2 100644
--- a/drivers/gpu/nova-core/gsp.rs
+++ b/drivers/gpu/nova-core/gsp.rs
@@ -17,6 +17,7 @@
io_write,
Io, //
},
+ num::casts,
pci,
prelude::*, //
};
@@ -48,7 +49,6 @@
cmdq::Cmdq,
fw::GspArgumentsPadded, //
},
- num,
vgpu::VgpuManager, //
};
@@ -92,7 +92,7 @@ fn init(view: CoherentView<'_, Self>, start: DmaAddress) -> Result<()> {
for i in 0..NUM_PAGES {
io_write!(view, .0[build: i],
start
- .checked_add(num::usize_as_u64(i) << GSP_PAGE_SHIFT)
+ .checked_add(casts::usize_as_u64(i) << GSP_PAGE_SHIFT)
.ok_or(EOVERFLOW)?
);
}
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 6da728201281..f85fde09aa6e 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -23,6 +23,7 @@
Io, //
},
new_mutex,
+ num::casts,
prelude::*,
ptr,
sync::{
@@ -57,7 +58,6 @@
GSP_PAGE_SHIFT,
GSP_PAGE_SIZE, //
},
- num,
sbuffer::SBufferIter, //
};
@@ -162,7 +162,7 @@ fn read(
#[repr(C, align(0x1000))]
#[derive(Debug)]
struct MsgqData {
- data: [[u8; GSP_PAGE_SIZE]; num::u32_as_usize(MSGQ_NUM_PAGES)],
+ data: [[u8; GSP_PAGE_SIZE]; casts::u32_as_usize(MSGQ_NUM_PAGES)],
}
// Annoyingly we are forced to use a literal to specify the alignment of
@@ -235,8 +235,8 @@ unsafe impl FromBytes for GspMem {}
impl DmaGspMem {
/// Allocate a new instance and map it for `dev`.
fn new(dev: &device::Device<device::Bound>) -> Result<Self> {
- const MSGQ_SIZE: u32 = num::usize_into_u32::<{ size_of::<Msgq>() }>();
- const RX_HDR_OFF: u32 = num::usize_into_u32::<{ mem::offset_of!(Msgq, rx) }>();
+ const MSGQ_SIZE: u32 = casts::usize_into_u32::<{ size_of::<Msgq>() }>();
+ const RX_HDR_OFF: u32 = casts::usize_into_u32::<{ mem::offset_of!(Msgq, rx) }>();
let mut gsp_mem = CoherentBox::<GspMem>::zeroed(dev, GFP_KERNEL)?;
gsp_mem.cpuq.tx = MsgqTxHeader::new(MSGQ_SIZE, RX_HDR_OFF, MSGQ_NUM_PAGES);
@@ -289,10 +289,10 @@ fn new(dev: &device::Device<device::Bound>) -> Result<Self> {
unsafe {
(
core::slice::from_raw_parts_mut(
- data.add(num::u32_as_usize(tx)),
- num::u32_as_usize(tail_end - tx),
+ data.add(casts::u32_as_usize(tx)),
+ casts::u32_as_usize(tail_end - tx),
),
- core::slice::from_raw_parts_mut(data, num::u32_as_usize(wrap_end)),
+ core::slice::from_raw_parts_mut(data, casts::u32_as_usize(wrap_end)),
)
}
}
@@ -307,7 +307,7 @@ fn driver_write_area_size(&self) -> usize {
// `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
+ casts::u32_as_usize(slots) * GSP_PAGE_SIZE
}
/// Returns the region of the GSP message queue that the driver is currently allowed to read
@@ -343,10 +343,10 @@ fn driver_write_area_size(&self) -> usize {
unsafe {
(
core::slice::from_raw_parts(
- data.add(num::u32_as_usize(rx)),
- num::u32_as_usize(tail_end - rx),
+ data.add(casts::u32_as_usize(rx)),
+ casts::u32_as_usize(tail_end - rx),
),
- core::slice::from_raw_parts(data, num::u32_as_usize(wrap_end)),
+ core::slice::from_raw_parts(data, casts::u32_as_usize(wrap_end)),
)
}
}
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 05f54fee6186..88f083ff1f13 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -19,6 +19,10 @@
io_read,
io_write, //
},
+ num::casts::{
+ self,
+ FromSafeCast, //
+ },
prelude::*,
ptr::{
Alignable,
@@ -49,15 +53,11 @@
cmdq::Cmdq, //
GSP_PAGE_SIZE,
},
- num::{
- self,
- FromSafeCast, //
- },
};
/// 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);
+ casts::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 {}
@@ -110,19 +110,19 @@ pub(crate) struct LibosParams {
impl LibosParams {
/// Version 2 of the GSP LIBOS (Turing and GA100)
const LIBOS2: LibosParams = LibosParams {
- carveout_size: num::u32_as_u64(bindings::GSP_FW_HEAP_PARAM_OS_SIZE_LIBOS2),
- allowed_heap_size: num::u32_as_u64(bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS2_MIN_MB)
+ carveout_size: casts::u32_as_u64(bindings::GSP_FW_HEAP_PARAM_OS_SIZE_LIBOS2),
+ allowed_heap_size: casts::u32_as_u64(bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS2_MIN_MB)
* u64::SZ_1M
- ..num::u32_as_u64(bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS2_MAX_MB) * u64::SZ_1M,
+ ..casts::u32_as_u64(bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS2_MAX_MB) * u64::SZ_1M,
};
/// Version 3 of the GSP LIBOS (GA102+)
const LIBOS3: LibosParams = LibosParams {
- carveout_size: num::u32_as_u64(bindings::GSP_FW_HEAP_PARAM_OS_SIZE_LIBOS3_BAREMETAL),
- allowed_heap_size: num::u32_as_u64(
+ carveout_size: casts::u32_as_u64(bindings::GSP_FW_HEAP_PARAM_OS_SIZE_LIBOS3_BAREMETAL),
+ allowed_heap_size: casts::u32_as_u64(
bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS3_BAREMETAL_MIN_MB,
) * u64::SZ_1M
- ..num::u32_as_u64(bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS3_BAREMETAL_MAX_MB)
+ ..casts::u32_as_u64(bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS3_BAREMETAL_MAX_MB)
* u64::SZ_1M,
};
@@ -681,11 +681,11 @@ fn id8(name: &str) -> u64 {
let init_inner = init!(bindings::LibosMemoryRegionInitArgument {
id8: id8(name),
pa: obj.dma_address(),
- size: num::usize_as_u64(obj.size()),
- kind: num::u32_into_u8::<
+ size: casts::usize_as_u64(obj.size()),
+ kind: casts::u32_into_u8::<
{ bindings::LibosMemoryRegionKind_LIBOS_MEMORY_REGION_CONTIGUOUS },
>(),
- loc: num::u32_into_u8::<
+ loc: casts::u32_into_u8::<
{ bindings::LibosMemoryRegionLoc_LIBOS_MEMORY_REGION_LOC_SYSMEM },
>(),
..Zeroable::init_zeroed()
@@ -715,12 +715,12 @@ pub(crate) fn new(msgq_size: u32, rx_hdr_offset: u32, msg_count: u32) -> Self {
Self(bindings::msgqTxHeader {
version: 0,
size: msgq_size,
- msgSize: num::usize_into_u32::<GSP_PAGE_SIZE>(),
+ msgSize: casts::usize_into_u32::<GSP_PAGE_SIZE>(),
msgCount: msg_count,
writePtr: 0,
flags: 1,
rxHdrOff: rx_hdr_offset,
- entryOff: num::usize_into_u32::<GSP_PAGE_SIZE>(),
+ entryOff: casts::usize_into_u32::<GSP_PAGE_SIZE>(),
})
}
@@ -851,7 +851,7 @@ pub(crate) fn set_checksum(&mut self, checksum: u32) {
/// Returns the length of the message's payload.
pub(crate) fn payload_length(&self) -> usize {
// `rpc.length` includes the length of the RPC message header.
- num::u32_as_usize(self.inner.rpc.length)
+ casts::u32_as_usize(self.inner.rpc.length)
.saturating_sub(size_of::<bindings::rpc_message_header_v>())
}
@@ -947,9 +947,9 @@ impl MessageQueueInitArguments {
fn new(cmdq: &Cmdq) -> impl Init<Self> + '_ {
init!(MessageQueueInitArguments {
sharedMemPhysAddr: cmdq.dma_addr,
- pageTableEntryCount: num::usize_into_u32::<{ Cmdq::NUM_PTES }>(),
- cmdQueueOffset: num::usize_as_u64(Cmdq::CMDQ_OFFSET),
- statQueueOffset: num::usize_as_u64(Cmdq::STATQ_OFFSET),
+ pageTableEntryCount: casts::usize_into_u32::<{ Cmdq::NUM_PTES }>(),
+ cmdQueueOffset: casts::usize_as_u64(Cmdq::CMDQ_OFFSET),
+ statQueueOffset: casts::usize_as_u64(Cmdq::STATQ_OFFSET),
..Zeroable::init_zeroed()
})
}
@@ -969,7 +969,7 @@ impl GspAcrBootGspRmParams {
fn new(target: GspDmaTarget, wpr_meta_addr: u64) -> impl Init<Self> {
let params = init!(Self {
target: target as u32,
- gspRmDescSize: num::usize_into_u32::<{ size_of::<GspFwWprMeta>() }>(),
+ gspRmDescSize: casts::usize_into_u32::<{ size_of::<GspFwWprMeta>() }>(),
gspRmDescOffset: wpr_meta_addr,
bIsGspRmBoot: 1,
wprCarveoutOffset: 0,
diff --git a/drivers/gpu/nova-core/gsp/fw/commands.rs b/drivers/gpu/nova-core/gsp/fw/commands.rs
index 6dc31d1bf5ae..201594fa437b 100644
--- a/drivers/gpu/nova-core/gsp/fw/commands.rs
+++ b/drivers/gpu/nova-core/gsp/fw/commands.rs
@@ -5,6 +5,7 @@
use kernel::{
device,
+ num::casts::IntoSafeCast,
pci,
prelude::*,
transmute::{
@@ -15,8 +16,7 @@
use crate::{
gpu::Chipset,
- gsp::GSP_PAGE_SIZE,
- num::IntoSafeCast, //
+ gsp::GSP_PAGE_SIZE, //
};
use super::bindings;
diff --git a/drivers/gpu/nova-core/gsp/sequencer.rs b/drivers/gpu/nova-core/gsp/sequencer.rs
index bcad1421953a..fed881ba80b0 100644
--- a/drivers/gpu/nova-core/gsp/sequencer.rs
+++ b/drivers/gpu/nova-core/gsp/sequencer.rs
@@ -11,6 +11,7 @@
poll::read_poll_timeout,
Io, //
},
+ num::casts::FromSafeCast,
prelude::*,
time::{
delay::fsleep,
@@ -35,7 +36,6 @@
GspBootContext,
LibosMemoryRegionInitArgument, //
},
- num::FromSafeCast,
sbuffer::SBufferIter,
};
diff --git a/drivers/gpu/nova-core/mctp.rs b/drivers/gpu/nova-core/mctp.rs
index 90c642c91a72..67f64ac2b8d1 100644
--- a/drivers/gpu/nova-core/mctp.rs
+++ b/drivers/gpu/nova-core/mctp.rs
@@ -9,14 +9,12 @@
use kernel::{
bitfield,
+ num::casts,
pci::Vendor,
prelude::*, //
};
-use crate::{
- bounded_enum,
- num, //
-};
+use crate::bounded_enum;
bounded_enum! {
/// NVDM message type identifiers carried over MCTP.
@@ -76,7 +74,7 @@ impl NvdmHeader {
/// Builds an NVDM header for the given message type.
pub(crate) fn new(nvdm_type: NvdmType) -> Self {
Self::zeroed()
- .with_const_msg_type::<{ num::u8_as_u32(MSG_TYPE_VENDOR_PCI) }>()
+ .with_const_msg_type::<{ casts::u8_as_u32(MSG_TYPE_VENDOR_PCI) }>()
.with_vendor_id(Vendor::NVIDIA.as_raw())
.with_nvdm_type(nvdm_type)
}
diff --git a/drivers/gpu/nova-core/num.rs b/drivers/gpu/nova-core/num.rs
index 6eb174d136ab..3921ef6f238e 100644
--- a/drivers/gpu/nova-core/num.rs
+++ b/drivers/gpu/nova-core/num.rs
@@ -5,217 +5,6 @@
//! This is essentially a staging module for code to mature until it can be moved to the `kernel`
//! crate.
-use kernel::{
- macros::paste,
- prelude::*, //
-};
-
-/// Implements safe `as` conversion functions from a given type into a series of target types.
-///
-/// These functions can be used in place of `as`, with the guarantee that they will be lossless.
-macro_rules! impl_safe_as {
- ($from:ty as { $($into:ty),* }) => {
- $(
- paste! {
- #[doc = ::core::concat!(
- "Losslessly converts a [`",
- ::core::stringify!($from),
- "`] into a [`",
- ::core::stringify!($into),
- "`].")]
- ///
- /// This conversion is allowed as it is always lossless. Prefer this over the `as`
- /// keyword to ensure no lossy casts are performed.
- ///
- /// This is for use from a `const` context. For non `const` use, prefer the
- /// [`FromSafeCast`] and [`IntoSafeCast`] traits.
- ///
- /// # Examples
- ///
- /// ```
- /// use crate::num;
- ///
- #[doc = ::core::concat!(
- "assert_eq!(num::",
- ::core::stringify!($from),
- "_as_",
- ::core::stringify!($into),
- "(1",
- ::core::stringify!($from),
- "), 1",
- ::core::stringify!($into),
- ");")]
- /// ```
- #[allow(unused)]
- #[inline(always)]
- pub(crate) const fn [<$from _as_ $into>](value: $from) -> $into {
- ::kernel::build_assert::static_assert!(size_of::<$into>() >= size_of::<$from>());
-
- value as $into
- }
- }
- )*
- };
-}
-
-impl_safe_as!(u8 as { u16, u32, u64, usize });
-impl_safe_as!(u16 as { u32, u64, usize });
-impl_safe_as!(u32 as { u64, usize } );
-// `u64` and `usize` have the same size on 64-bit platforms.
-#[cfg(CONFIG_64BIT)]
-impl_safe_as!(u64 as { usize } );
-
-// A `usize` fits into a `u64` on 32 and 64-bit platforms.
-#[cfg(any(CONFIG_32BIT, CONFIG_64BIT))]
-impl_safe_as!(usize as { u64 });
-
-// A `usize` fits into a `u32` on 32-bit platforms.
-#[cfg(CONFIG_32BIT)]
-impl_safe_as!(usize as { u32 });
-
-/// Extension trait providing guaranteed lossless cast to `Self` from `T`.
-///
-/// The standard library's `From` implementations do not cover conversions that are not portable or
-/// future-proof. For instance, even though it is safe today, `From<usize>` is not implemented for
-/// [`u64`] because of the possibility to support larger-than-64bit architectures in the future.
-///
-/// The workaround is to either deal with the error handling of [`TryFrom`] for an operation that
-/// technically cannot fail, or to use the `as` keyword, which can silently strip data if the
-/// destination type is smaller than the source.
-///
-/// Both options are hardly acceptable for the kernel. It is also a much more architecture
-/// dependent environment, supporting only 32 and 64 bit architectures, with some modules
-/// explicitly depending on a specific bus width that could greatly benefit from infallible
-/// conversion operations.
-///
-/// Thus this extension trait that provides, for the architecture the kernel is built for, safe
-/// conversion between types for which such cast is lossless.
-///
-/// In other words, this trait is implemented if, for the current build target and with `t: T`, the
-/// `t as Self` operation is completely lossless.
-///
-/// Prefer this over the `as` keyword to ensure no lossy casts are performed.
-///
-/// If you need to perform a conversion in `const` context, use [`u64_as_usize`], [`u32_as_usize`],
-/// [`usize_as_u64`], etc.
-///
-/// # Examples
-///
-/// ```
-/// use crate::num::FromSafeCast;
-///
-/// assert_eq!(usize::from_safe_cast(0xf00u32), 0xf00u32 as usize);
-/// ```
-pub(crate) trait FromSafeCast<T> {
- /// Create a `Self` from `value`. This operation is guaranteed to be lossless.
- fn from_safe_cast(value: T) -> Self;
-}
-
-impl FromSafeCast<usize> for u64 {
- fn from_safe_cast(value: usize) -> Self {
- usize_as_u64(value)
- }
-}
-
-#[cfg(CONFIG_32BIT)]
-impl FromSafeCast<usize> for u32 {
- fn from_safe_cast(value: usize) -> Self {
- usize_as_u32(value)
- }
-}
-
-impl FromSafeCast<u32> for usize {
- fn from_safe_cast(value: u32) -> Self {
- u32_as_usize(value)
- }
-}
-
-#[cfg(CONFIG_64BIT)]
-impl FromSafeCast<u64> for usize {
- fn from_safe_cast(value: u64) -> Self {
- u64_as_usize(value)
- }
-}
-
-/// Counterpart to the [`FromSafeCast`] trait, i.e. this trait is to [`FromSafeCast`] what [`Into`]
-/// is to [`From`].
-///
-/// See the documentation of [`FromSafeCast`] for the motivation.
-///
-/// # Examples
-///
-/// ```
-/// use crate::num::IntoSafeCast;
-///
-/// assert_eq!(0xf00u32.into_safe_cast(), 0xf00u32 as usize);
-/// ```
-pub(crate) trait IntoSafeCast<T> {
- /// Convert `self` into a `T`. This operation is guaranteed to be lossless.
- fn into_safe_cast(self) -> T;
-}
-
-/// Reverse operation for types implementing [`FromSafeCast`].
-impl<S, T> IntoSafeCast<T> for S
-where
- T: FromSafeCast<S>,
-{
- fn into_safe_cast(self) -> T {
- T::from_safe_cast(self)
- }
-}
-
-/// Implements lossless conversion of a constant from a larger type into a smaller one.
-macro_rules! impl_const_into {
- ($from:ty => { $($into:ty),* }) => {
- $(
- paste! {
- #[doc = ::core::concat!(
- "Performs a build-time safe conversion of a [`",
- ::core::stringify!($from),
- "`] constant value into a [`",
- ::core::stringify!($into),
- "`].")]
- ///
- /// This checks at compile-time that the conversion is lossless, and triggers a build
- /// error if it isn't.
- ///
- /// # Examples
- ///
- /// ```
- /// use crate::num;
- ///
- /// // Succeeds because the value of the source fits into the destination's type.
- #[doc = ::core::concat!(
- "assert_eq!(num::",
- ::core::stringify!($from),
- "_into_",
- ::core::stringify!($into),
- "::<1",
- ::core::stringify!($from),
- ">(), 1",
- ::core::stringify!($into),
- ");")]
- /// ```
- #[allow(unused)]
- pub(crate) const fn [<$from _into_ $into>]<const N: $from>() -> $into {
- // Make sure that the target type is smaller than the source one.
- static_assert!($from::BITS >= $into::BITS);
- // CAST: we statically enforced above that `$from` is larger than `$into`, so the
- // `as` conversion will be lossless.
- build_assert!(N >= $into::MIN as $from && N <= $into::MAX as $from);
-
- N as $into
- }
- }
- )*
- };
-}
-
-impl_const_into!(usize => { u8, u16, u32 });
-impl_const_into!(u64 => { u8, u16, u32 });
-impl_const_into!(u32 => { u8, u16 });
-impl_const_into!(u16 => { u8 });
-
/// Creates an enum type associated to a [`Bounded`](kernel::num::Bounded), with a [`From`]
/// conversion to the associated `Bounded` and either a [`TryFrom`] or `From` conversion from the
/// associated `Bounded`.
diff --git a/drivers/gpu/nova-core/vbios.rs b/drivers/gpu/nova-core/vbios.rs
index c03650ee5226..7a2ee29cbb91 100644
--- a/drivers/gpu/nova-core/vbios.rs
+++ b/drivers/gpu/nova-core/vbios.rs
@@ -5,6 +5,7 @@
use kernel::{
device,
io::Io,
+ num::casts::FromSafeCast,
prelude::*,
ptr::{
Alignable,
@@ -23,7 +24,6 @@
FalconUCodeDescV2,
FalconUCodeDescV3, //
},
- num::FromSafeCast,
};
/// BIOS Image Type from PCI Data Structure code_type field.
--
2.55.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH 2/2] gpu: nova-core: use FromSafeCast wherever possible
2026-08-28 5:33 [PATCH 0/2] gpu: nova-core: complete conversion to kernel `num` module Alexandre Courbot
2026-08-28 5:33 ` [PATCH 1/2] gpu: nova-core: use kernel lossless integer conversion module Alexandre Courbot
@ 2026-08-28 5:33 ` Alexandre Courbot
2026-08-28 5:42 ` Eliot Courtney
2026-08-28 5:49 ` sashiko-bot
1 sibling, 2 replies; 9+ messages in thread
From: Alexandre Courbot @ 2026-08-28 5:33 UTC (permalink / raw)
To: Danilo Krummrich, Alice Ryhl, David Airlie, Simona Vetter
Cc: John Hubbard, Alistair Popple, Timur Tabi, Eliot Courtney,
Zhi Wang, nova-gpu, dri-devel, rust-for-linux, linux-kernel,
Alexandre Courbot
`FromSafeCast` should be preferred to the `*_as_*` family of functions
when it can be used (i.e. in non-const contexts), as it requires a
single import to perform all valid conversions.
After this patch, the only remaining references to the `casts` module
are those done in const context, which means the `casts` import can be
removed once these are converted to use the `cv!` macro.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
drivers/gpu/nova-core/falcon/fsp.rs | 4 ++--
drivers/gpu/nova-core/firmware/tlv.rs | 4 ++--
drivers/gpu/nova-core/gsp.rs | 4 ++--
drivers/gpu/nova-core/gsp/cmdq.rs | 19 +++++++++++--------
drivers/gpu/nova-core/gsp/fw.rs | 8 ++++----
5 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/drivers/gpu/nova-core/falcon/fsp.rs b/drivers/gpu/nova-core/falcon/fsp.rs
index 2470ac511c98..ece95b1ea8cb 100644
--- a/drivers/gpu/nova-core/falcon/fsp.rs
+++ b/drivers/gpu/nova-core/falcon/fsp.rs
@@ -16,7 +16,7 @@
},
Io, //
},
- num::casts,
+ num::casts::FromSafeCast,
prelude::*,
sizes::SZ_1K,
time::Delta,
@@ -165,7 +165,7 @@ pub(crate) fn recv_msg(&mut self) -> Result<KVec<u8>> {
Delta::from_millis(10),
Delta::from_millis(FSP_MSG_TIMEOUT_MS),
)
- .map(casts::u32_as_usize)?;
+ .map(usize::from_safe_cast)?;
// Don't blindly allocate more than the maximum we expect from FSP.
if msg_size > FSP_EMEM_CHANNEL_0_SIZE {
diff --git a/drivers/gpu/nova-core/firmware/tlv.rs b/drivers/gpu/nova-core/firmware/tlv.rs
index 6653c10e3e0a..7dff8871e338 100644
--- a/drivers/gpu/nova-core/firmware/tlv.rs
+++ b/drivers/gpu/nova-core/firmware/tlv.rs
@@ -5,7 +5,7 @@
device,
firmware,
num::casts::{
- self,
+ FromSafeCast,
IntoSafeCast, //
},
prelude::*,
@@ -52,7 +52,7 @@ fn parse(hdr: &[u8]) -> Option<Self> {
return None;
}
let len_arr = <[u8; 4]>::try_from(hdr.get(4..Self::SIZE)?).ok()?;
- let length = casts::u32_as_usize(u32::from_le_bytes(len_arr));
+ let length = usize::from_safe_cast(u32::from_le_bytes(len_arr));
Some(Self { tag, length })
}
}
diff --git a/drivers/gpu/nova-core/gsp.rs b/drivers/gpu/nova-core/gsp.rs
index fc8648de84c2..0f5275dcb41c 100644
--- a/drivers/gpu/nova-core/gsp.rs
+++ b/drivers/gpu/nova-core/gsp.rs
@@ -17,7 +17,7 @@
io_write,
Io, //
},
- num::casts,
+ num::casts::FromSafeCast,
pci,
prelude::*, //
};
@@ -92,7 +92,7 @@ fn init(view: CoherentView<'_, Self>, start: DmaAddress) -> Result<()> {
for i in 0..NUM_PAGES {
io_write!(view, .0[build: i],
start
- .checked_add(casts::usize_as_u64(i) << GSP_PAGE_SHIFT)
+ .checked_add(u64::from_safe_cast(i) << GSP_PAGE_SHIFT)
.ok_or(EOVERFLOW)?
);
}
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index f85fde09aa6e..658d0a9b2cfb 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -23,7 +23,10 @@
Io, //
},
new_mutex,
- num::casts,
+ num::casts::{
+ self,
+ FromSafeCast, //
+ },
prelude::*,
ptr,
sync::{
@@ -289,10 +292,10 @@ fn new(dev: &device::Device<device::Bound>) -> Result<Self> {
unsafe {
(
core::slice::from_raw_parts_mut(
- data.add(casts::u32_as_usize(tx)),
- casts::u32_as_usize(tail_end - tx),
+ data.add(usize::from_safe_cast(tx)),
+ usize::from_safe_cast(tail_end - tx),
),
- core::slice::from_raw_parts_mut(data, casts::u32_as_usize(wrap_end)),
+ core::slice::from_raw_parts_mut(data, usize::from_safe_cast(wrap_end)),
)
}
}
@@ -307,7 +310,7 @@ fn driver_write_area_size(&self) -> usize {
// `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;
- casts::u32_as_usize(slots) * GSP_PAGE_SIZE
+ usize::from_safe_cast(slots) * GSP_PAGE_SIZE
}
/// Returns the region of the GSP message queue that the driver is currently allowed to read
@@ -343,10 +346,10 @@ fn driver_write_area_size(&self) -> usize {
unsafe {
(
core::slice::from_raw_parts(
- data.add(casts::u32_as_usize(rx)),
- casts::u32_as_usize(tail_end - rx),
+ data.add(usize::from_safe_cast(rx)),
+ usize::from_safe_cast(tail_end - rx),
),
- core::slice::from_raw_parts(data, casts::u32_as_usize(wrap_end)),
+ core::slice::from_raw_parts(data, usize::from_safe_cast(wrap_end)),
)
}
}
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 88f083ff1f13..61064b6a251b 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -681,7 +681,7 @@ fn id8(name: &str) -> u64 {
let init_inner = init!(bindings::LibosMemoryRegionInitArgument {
id8: id8(name),
pa: obj.dma_address(),
- size: casts::usize_as_u64(obj.size()),
+ size: u64::from_safe_cast(obj.size()),
kind: casts::u32_into_u8::<
{ bindings::LibosMemoryRegionKind_LIBOS_MEMORY_REGION_CONTIGUOUS },
>(),
@@ -851,7 +851,7 @@ pub(crate) fn set_checksum(&mut self, checksum: u32) {
/// Returns the length of the message's payload.
pub(crate) fn payload_length(&self) -> usize {
// `rpc.length` includes the length of the RPC message header.
- casts::u32_as_usize(self.inner.rpc.length)
+ usize::from_safe_cast(self.inner.rpc.length)
.saturating_sub(size_of::<bindings::rpc_message_header_v>())
}
@@ -948,8 +948,8 @@ fn new(cmdq: &Cmdq) -> impl Init<Self> + '_ {
init!(MessageQueueInitArguments {
sharedMemPhysAddr: cmdq.dma_addr,
pageTableEntryCount: casts::usize_into_u32::<{ Cmdq::NUM_PTES }>(),
- cmdQueueOffset: casts::usize_as_u64(Cmdq::CMDQ_OFFSET),
- statQueueOffset: casts::usize_as_u64(Cmdq::STATQ_OFFSET),
+ cmdQueueOffset: u64::from_safe_cast(Cmdq::CMDQ_OFFSET),
+ statQueueOffset: u64::from_safe_cast(Cmdq::STATQ_OFFSET),
..Zeroable::init_zeroed()
})
}
--
2.55.0
^ permalink raw reply related [flat|nested] 9+ messages in thread