[PATCH v13 00/13] Linux RISC-V AIA Support

[Björn Töpel]

Anup Patel <apatel at ventanamicro.com> writes:

> The RISC-V AIA specification is ratified as-per the RISC-V international
> process. The latest ratified AIA specifcation can be found at:
> https://github.com/riscv/riscv-aia/releases/download/1.0/riscv-interrupts-1.0.pdf
>
> At a high-level, the AIA specification adds three things:
> 1) AIA CSRs
>    - Improved local interrupt support
> 2) Incoming Message Signaled Interrupt Controller (IMSIC)
>    - Per-HART MSI controller
>    - Support MSI virtualization
>    - Support IPI along with virtualization
> 3) Advanced Platform-Level Interrupt Controller (APLIC)
>    - Wired interrupt controller
>    - In MSI-mode, converts wired interrupt into MSIs (i.e. MSI generator)
>    - In Direct-mode, injects external interrupts directly into HARTs
>
> For an overview of the AIA specification, refer the AIA virtualization
> talk at KVM Forum 2022:
> https://static.sched.com/hosted_files/kvmforum2022/a1/AIA_Virtualization_in_KVM_RISCV_final.pdf
> https://www.youtube.com/watch?v=r071dL8Z0yo
>
> To test this series, use QEMU v7.2 (or higher) and OpenSBI v1.2 (or higher).
>
> This series depends upon per-device MSI domain patches merged by Thomas (tglx)
> which are available in irq/msi branch at:
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
>
> These patches can also be found in the riscv_aia_v13 branch at:
> https://github.com/avpatel/linux.git
>
> Changes since v12:
>  - Rebased on Linux-6.8-rc5
>  - Dropped per-device MSI domain patches which are already merged by Thomas (tglx)
>  - Addressed nit comments from Thomas and Clement
>  - Added a new patch2 to fix lock dependency warning
>  - Replaced local sync IPI in the IMSIC driver with per-CPU timer
>  - Simplified locking in the IMSIC driver to avoid lock dependency issues
>  - Added a dirty bitmap in the IMSIC driver to optimize per-CPU local sync loop

Thanks, Anup.

I will take it for a spin, with Alex' v1 of the stop_machine()/ftrace
IPI fix.

The defconfig change (12/13)breaks a bunch a builds:
https://patchwork.kernel.org/project/linux-riscv/list/?series=827706

Download the logs here:
https://github.com/linux-riscv/linux-riscv/suites/20917102160/logs?attempt=1
and grep for '##[error]'

Björn