Re: [PATCH v16 0/9] Linux RISC-V AIA Support

[Anup Patel]

Hi Thomas,

On Thu, Mar 7, 2024 at 7:33 PM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote:
>
> 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 (and few other) 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_v16 branch at:
> https://github.com/avpatel/linux.git
>
> Changes since v15:
>  - Dropped PATCH1 since it is already merged by Thomas (tglx) and available in
>    his irq/msi branch at git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
>  - Simplified aplic_msi_irq_eoi() in PATCH7 based on the section "4.9.2 Special
>    consideration for level-sensitive interrupt sources"  of the RISC-V AIA
>    specification and also provided handler name.
>
> Changes since v14:
>  - Dropped 9 patches which are already merged by Thomas (tglx) and available in
>    his irq/msi branch at git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
>  - Added new PATCH1 which adds changes missed out in merging AIA support for
>    RISC-V INTC.
>  - Added a separate cpuhp state for IMSIC driver in PATCH3 which ensures that
>    cpuhp notifiers of IMSIC are called as early as possible.
>  - Removed redundant barriers in PATCH3.
>  - Addressed few other nit comments.
>
> Changes since v13:
>  - Split PATCH1 into six granular patches
>  - Addressed nit comments from Thomas and Bjorn
>
> 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
>
> Changes since v11:
>  - Rebased on Linux-6.8-rc1
>  - Included kernel/irq related patches from "genirq, irqchip: Convert ARM
>    MSI handling to per device MSI domains" series by Thomas.
>    (PATCH7, PATCH8, PATCH9, PATCH14, PATCH16, PATCH17, PATCH18, PATCH19,
>     PATCH20, PATCH21, PATCH22, PATCH23, and PATCH32 of
>     https://lore.kernel.org/linux-arm-kernel/20221121135653.208611233@xxxxxxxxxxxxx/)
>  - Updated APLIC MSI-mode driver to use the new WIRED_TO_MSI mechanism.
>  - Updated IMSIC driver to support per-device MSI domains for PCI and
>    platform devices.
>
> Changes since v10:
>  - Rebased on Linux-6.6-rc7
>  - Dropped PATCH3 of v10 series since this has been merged by MarcZ
>    for Linux-6.6-rc7
>  - Changed the IMSIC ID management strategy from 1-n approach to
>    x86-style 1-1 approach
>
> Changes since v9:
>  - Rebased on Linux-6.6-rc4
>  - Use builtin_platform_driver() in PATCH5, PATCH9, and PATCH12
>
> Changes since v8:
>  - Rebased on Linux-6.6-rc3
>  - Dropped PATCH2 of v8 series since we won't be requiring
>    riscv_get_intc_hartid() based on Marc Z's comments on ACPI AIA support.
>  - Addressed Saravana's comments in PATCH3 of v8 series
>  - Update PATCH9 and PATCH13 of v8 series based on comments from Sunil
>
> Changes since v7:
>  - Rebased on Linux-6.6-rc1
>  - Addressed comments on PATCH1 of v7 series and split it into two PATCHes
>  - Use DEFINE_SIMPLE_PROP() in PATCH2 of v7 series
>
> Changes since v6:
>  - Rebased on Linux-6.5-rc4
>  - Updated PATCH2 to use IS_ENABLED(CONFIG_SPARC) instead of
>    !IS_ENABLED(CONFIG_OF_IRQ)
>  - Added new PATCH4 to fix syscore registration in PLIC driver
>  - Update PATCH5 to convert PLIC driver into full-blown platform driver
>    with a re-written probe function.
>
> Changes since v5:
>  - Rebased on Linux-6.5-rc2
>  - Updated the overall series to ensure that only IPI, timer, and
>    INTC drivers are probed very early whereas rest of the interrupt
>    controllers (such as PLIC, APLIC, and IMISC) are probed as
>    regular platform drivers.
>  - Renamed riscv_fw_parent_hartid() to riscv_get_intc_hartid()
>  - New PATCH1 to add fw_devlink support for msi-parent DT property
>  - New PATCH2 to ensure all INTC suppliers are initialized which in-turn
>    fixes the probing issue for PLIC, APLIC and IMSIC as platform driver
>  - New PATCH3 to use platform driver probing for PLIC
>  - Re-structured the IMSIC driver into two separate drivers: early and
>    platform. The IMSIC early driver (PATCH7) only initialized IMSIC state
>    and provides IPIs whereas the IMSIC platform driver (PATCH8) is probed
>    provides MSI domain for platform devices.
>  - Re-structure the APLIC platform driver into three separe sources: main,
>    direct mode, and MSI mode.
>
> Changes since v4:
>  - Rebased on Linux-6.5-rc1
>  - Added "Dependencies" in the APLIC bindings (PATCH6 in v4)
>  - Dropped the PATCH6 which was changing the IOMMU DMA domain APIs
>  - Dropped use of IOMMU DMA APIs in the IMSIC driver (PATCH4)
>
> Changes since v3:
>  - Rebased on Linux-6.4-rc6
>  - Dropped PATCH2 of v3 series instead we now set FWNODE_FLAG_BEST_EFFORT via
>    IRQCHIP_DECLARE()
>  - Extend riscv_fw_parent_hartid() to support both DT and ACPI in PATCH1
>  - Extend iommu_dma_compose_msi_msg() instead of adding iommu_dma_select_msi()
>    in PATCH6
>  - Addressed Conor's comments in PATCH3
>  - Addressed Conor's and Rob's comments in PATCH7
>
> Changes since v2:
>  - Rebased on Linux-6.4-rc1
>  - Addressed Rob's comments on DT bindings patches 4 and 8.
>  - Addessed Marc's comments on IMSIC driver PATCH5
>  - Replaced use of OF apis in APLIC and IMSIC drivers with FWNODE apis
>    this makes both drivers easily portable for ACPI support. This also
>    removes unnecessary indirection from the APLIC and IMSIC drivers.
>  - PATCH1 is a new patch for portability with ACPI support
>  - PATCH2 is a new patch to fix probing in APLIC drivers for APLIC-only systems.
>  - PATCH7 is a new patch which addresses the IOMMU DMA domain issues pointed
>    out by SiFive
>
> Changes since v1:
>  - Rebased on Linux-6.2-rc2
>  - Addressed comments on IMSIC DT bindings for PATCH4
>  - Use raw_spin_lock_irqsave() on ids_lock for PATCH5
>  - Improved MMIO alignment checks in PATCH5 to allow MMIO regions
>    with holes.
>  - Addressed comments on APLIC DT bindings for PATCH6
>  - Fixed warning splat in aplic_msi_write_msg() caused by
>    zeroed MSI message in PATCH7
>  - Dropped DT property riscv,slow-ipi instead will have module
>    parameter in future.
>
> Anup Patel (9):
>   dt-bindings: interrupt-controller: Add RISC-V incoming MSI controller
>   irqchip: Add RISC-V incoming MSI controller early driver
>   irqchip/riscv-imsic: Add device MSI domain support for platform
>     devices
>   irqchip/riscv-imsic: Add device MSI domain support for PCI devices
>   dt-bindings: interrupt-controller: Add RISC-V advanced PLIC
>   irqchip: Add RISC-V advanced PLIC driver for direct-mode
>   irqchip/riscv-aplic: Add support for MSI-mode
>   RISC-V: Select APLIC and IMSIC drivers
>   MAINTAINERS: Add entry for RISC-V AIA drivers

Can this series be considered for Linux-6.9 ?

Regards,
Anup

>
>  .../interrupt-controller/riscv,aplic.yaml     | 172 ++++
>  .../interrupt-controller/riscv,imsics.yaml    | 172 ++++
>  MAINTAINERS                                   |  14 +
>  arch/riscv/Kconfig                            |   2 +
>  drivers/irqchip/Kconfig                       |  25 +
>  drivers/irqchip/Makefile                      |   3 +
>  drivers/irqchip/irq-riscv-aplic-direct.c      | 326 +++++++
>  drivers/irqchip/irq-riscv-aplic-main.c        | 211 +++++
>  drivers/irqchip/irq-riscv-aplic-main.h        |  52 ++
>  drivers/irqchip/irq-riscv-aplic-msi.c         | 257 ++++++
>  drivers/irqchip/irq-riscv-imsic-early.c       | 201 ++++
>  drivers/irqchip/irq-riscv-imsic-platform.c    | 374 ++++++++
>  drivers/irqchip/irq-riscv-imsic-state.c       | 865 ++++++++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.h       | 108 +++
>  include/linux/cpuhotplug.h                    |   1 +
>  include/linux/irqchip/riscv-aplic.h           | 145 +++
>  include/linux/irqchip/riscv-imsic.h           |  87 ++
>  17 files changed, 3015 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-msi.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
>  create mode 100644 include/linux/irqchip/riscv-aplic.h
>  create mode 100644 include/linux/irqchip/riscv-imsic.h
>
> --
> 2.34.1
>