If built on architectures with CONFIG_ARCH_DMA_ADDR_T_64BIT=y nova-core
produces that following build failures:
error[E0308]: mismatched types
--> drivers/gpu/nova-core/fb.rs:49:59
|
49 | hal::fb_hal(chipset).write_sysmem_flush_page(bar,
page.dma_handle())?;
| -----------------------
^^^^^^^^^^^^^^^^^ expected `u64`, found `u32`
| |
| arguments to this method are incorrect
|
note: method defined here
--> drivers/gpu/nova-core/fb/hal.rs:19:8
|
19 | fn write_sysmem_flush_page(&self, bar: &Bar0, addr: u64) -> Result;
| ^^^^^^^^^^^^^^^^^^^^^^^
help: you can convert a `u32` to a `u64`
|
49 | hal::fb_hal(chipset).write_sysmem_flush_page(bar,
page.dma_handle().into())?;
|
+++++++
error[E0308]: mismatched types
--> drivers/gpu/nova-core/fb.rs:65:47
|
65 | if hal.read_sysmem_flush_page(bar) == self.page.dma_handle() {
| ------------------------------- ^^^^^^^^^^^^^^^^^^^^^^
expected `u64`, found `u32`
| |
| expected because this is `u64`
|
help: you can convert a `u32` to a `u64`
|
65 | if hal.read_sysmem_flush_page(bar) ==
self.page.dma_handle().into() {
|
+++++++
error: this arithmetic operation will overflow
--> drivers/gpu/nova-core/falcon.rs:469:23
|
469 | .set_base((dma_start >> 40) as u16)
| ^^^^^^^^^^^^^^^^^ attempt to shift right by
`40_i32`, which would overflow
|
= note: `#[deny(arithmetic_overflow)]` on by default
This is due to the code making assumptions on the width of dma_addr_t to
be 64 bit.
While this could technically be handled, it is rather painful to deal
with, as the following example illustrates:
pub(super) fn read_sysmem_flush_page_ga100(bar: &Bar0) -> DmaAddress {
let addr =
u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR::read(bar).adr_39_08())
<< FLUSH_SYSMEM_ADDR_SHIFT
|
u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR_HI::read(bar).adr_63_40())
<< FLUSH_SYSMEM_ADDR_SHIFT_HI;
addr.try_into().unwrap_or_else(|_| {
kernel::warn_on!(true);
0
})
}
At the same time there's not much value for nova-core to support 32-bit,
given that the supported GPU architectures are Turing and later, hence
depend on CONFIG_64BIT.
Cc: John Hubbard <jhubb...@nvidia.com>
Reported-by: Miguel Ojeda <oj...@kernel.org>
Closes: https://lore.kernel.org/lkml/20250828160247.37492-1-oj...@kernel.org/
Fixes: 6554ad65b589 ("gpu: nova-core: register sysmem flush page")
Fixes: 69f5cd67ce41 ("gpu: nova-core: add falcon register definitions and base
code")
Signed-off-by: Danilo Krummrich <d...@kernel.org>
---
drivers/gpu/nova-core/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/nova-core/Kconfig b/drivers/gpu/nova-core/Kconfig
index 8726d80d6ba4..20d3e6d0d796 100644
--- a/drivers/gpu/nova-core/Kconfig
+++ b/drivers/gpu/nova-core/Kconfig
@@ -1,5 +1,6 @@
config NOVA_CORE
tristate "Nova Core GPU driver"
+ depends on 64BIT
depends on PCI
depends on RUST
depends on RUST_FW_LOADER_ABSTRACTIONS
base-commit: 1b237f190eb3d36f52dffe07a40b5eb210280e00
--
2.51.0
