Benno Lossin
2025-Oct-03 17:59 UTC
[PATCH v3 08/13] gpu: nova-core: Add bindings and accessors for GspSystemInfo
On Fri Oct 3, 2025 at 7:25 PM CEST, Janne Grunau wrote:> On Fri, Oct 03, 2025 at 06:34:12PM +0200, Benno Lossin wrote: >> On Thu Oct 2, 2025 at 3:49 PM CEST, Alexandre Courbot wrote: >> > Hi Alistair, (+Benno as this concerns the `init!` macros) >> > >> > On Tue Sep 30, 2025 at 10:16 PM JST, Alistair Popple wrote: >> >> Adds bindings and an in-place initialiser for the GspSystemInfo struct. >> >> >> >> Signed-off-by: Alistair Popple <apopple at nvidia.com> >> >> >> >> --- >> >> >> >> It would be good to move to using the `init!` macros at some point, but >> >> I couldn't figure out how to make that work to initialise an enum rather >> >> than a struct as is required for the transparent representation.Oh by the way, enums are not supported due to a language limitation, see: https://github.com/Rust-for-Linux/pin-init/issues/59>> > Indeed we have to jump through a few (minor) hoops. >> > >> > First the `init!` macros do not seem to support tuple structs. They >> > match a `{` after the type name, which is not present in >> > `GspSystemInfo`. By turning it into a regular struct with a single >> > field, we can overcome this, and it doesn't affect the layout the >> > `#[repr(transparent)]` can still be used. >> >> Yeah that's the correct workaround at the moment. I'm tracking support >> for tuple structs in [1]. Essentially the problem is that it requires >> lots of effort to parse tuple structs using declarative macros. We will >> get `syn` this cycle, which will enable me to support several things, >> including tuple structs. >> >> [1]: https://github.com/Rust-for-Linux/pin-init/issues/85 >> >> > Then, due to a limitation with declarative macros, `init!` interprets >> > `::` as a separator for generic arguments, so `bindings::GspSystemInfo` >> > also doesn't parse. Here the trick is to use a local type alias. >> >> This one will also be solved when we switch to syn. > > I was planning to submit > https://github.com/AsahiLinux/linux/commit/2d95fd3b6c359634a0976f27f7a3c667826256da > https://github.com/AsahiLinux/linux/commit/515638cb47cf0ebdac378686fcbbdc6a8364096a > from the asahi downstream tree after 6.18-rc1. Does that still make > sense timing wise?Probably not, since I'll depend on the syn patches this cycle which will mean that pin-init supports tuples in 6.19.> Types with type paths are used extensively in the asahi driver but I can > initially work around that.Yeah they should be supported simply by moving to syn, hope it doesn't introduce too much pain in the next cycle. --- Cheers, Benno