Re: [GIT PULL] asm-generic changes for 5.19

From: Marc Zyngier
Date: Sun May 29 2022 - 09:22:01 EST


On Sun, 29 May 2022 12:24:29 +0100,
Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> On Thu, May 26, 2022 at 5:00 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
> > - A series to add a generic ticket spinlock that can be shared by most
> > architectures with a working cmpxchg or ll/sc type atomic, including
> > the conversion of riscv, csky and openrisc. This series is also a
> > prerequisite for the loongarch64 architecture port that will come as
> > a separate pull request.
>
> An update on Loongarch: I was originally planning to send Linus a
> pull request with
> the branch with the contents from
>
> https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson.git/log/?h=loongarch-next
>
> but I saw that this includes both the architecture code and some
> device drivers (irqchip, pci, acpi) that are essential for the
> kernel to actually boot. At least the irqchip driver has not passed
> review because it uses a nonstandard way to integrate into ACPI, and
> the PCI stuff may or may not be ready but has no Reviewed-by or
> Acked-by tags from the maintainers. I clearly don't want to bypass
> the subsystem maintainers on those drivers by sending a pull request
> for the current branch.

It seems that there is now a new contributor on the irqchip front, and
the current approach *should* be better than the "copy MIPS and run"
approach that was previously taken. I'm still to find time to review
the new series (I just came back from a week off), but hopefully next
week.

> My feeling is that there is also no point in merging a port without
> the drivers as it cannot work on any hardware. On the other hand,
> the libc submissions (glibc and musl) are currently blocked while
> they are waiting for the kernel port to get merged.

I'd tend to agree. But if on the other hand the userspace ABI is
clearly defined, I think it could make sense to go for it (if I
remember well, we merged arm64 without any support irqchip support,
and the arm64 GIC support appeared later in the game).

Thanks,

M.

--
Without deviation from the norm, progress is not possible.