Re: [PATCH v4 0/5] New RISC-V Local Interrupt Controller Driver

[Anup Patel]

Fixed Marc's email address.

On Mon, Mar 9, 2020 at 4:32 PM Anup Patel <anup.patel@xxxxxxx> wrote:
>
> This patchset provides a new RISC-V Local Interrupt Controller Driver
> for managing per-CPU local interrupts. The overall approach is inspired
> from the way per-CPU local interrupts are handled by Linux ARM64 and
> ARM GICv3 driver.
>
> Few advantages of this new driver over previous one are:
> 1. It registers all local interrupts as per-CPU interrupts
> 2. The KVM RISC-V can use this driver to implement interrupt
>    handler for per-HART guest external interrupt defined by
>    the RISC-V H-Extension
> 3. In future, we can develop drivers for devices with per-HART
>    interrupts without changing arch code or this driver
>
> With this patchset, output of "cat /proc/interrupts" looks as follows:
>            CPU0       CPU1       CPU2       CPU3
>   2:        379          0          0          0  SiFive PLIC  10  ttyS0
>   3:        591          0          0          0  SiFive PLIC   8  virtio0
>   5:       5079      10821       8435      12984  RISC-V INTC   5  riscv-timer
> IPI0:      2045       2537        891        870  Rescheduling interrupts
> IPI1:         9        269         91        168  Function call interrupts
> IPI2:         0          0          0          0  CPU stop interrupts
>
> The patchset is based up Linux-5.6-rc5 and can be found at riscv_intc_v4
> branch of: https://github.com/avpatel/linux.git
>
> Changes since v3:
>  - Rebased to Linux-5.6-rc5 and Atish's PLIC patches
>  - Added separate patch to rename and move plic_find_hart_id()
>    to arch directory
>  - Use riscv_of_parent_hartid() in riscv_intc_init() instead of
>    atomic counter
>
> Changes since v2:
>  - Dropped PATCH2 since it was merged long-time back
>  - Rebased series from Linux-4.19-rc2 to Linux-5.6-rc2
>
> Changes since v1:
>  - Removed changes related to puggable IPI triggering
>  - Separate patch for self-contained IPI handling routine
>  - Removed patch for GENERIC_IRQ kconfig options
>  - Added patch to remove do_IRQ() function
>  - Rebased upon Atish's SMP patches
>
> Anup Patel (5):
>   RISC-V: self-contained IPI handling routine
>   RISC-V: Rename and move plic_find_hart_id() to arch directory
>   irqchip: RISC-V Per-HART Local Interrupt Controller Driver
>   clocksource: timer-riscv: Make timer interrupt as a per-CPU interrupt
>   RISC-V: Remove do_IRQ() function
>
>  arch/riscv/Kconfig                 |   1 +
>  arch/riscv/include/asm/irq.h       |   5 --
>  arch/riscv/include/asm/processor.h |   1 +
>  arch/riscv/include/asm/smp.h       |   3 +
>  arch/riscv/kernel/cpu.c            |  16 ++++
>  arch/riscv/kernel/entry.S          |   4 +-
>  arch/riscv/kernel/irq.c            |  33 +------
>  arch/riscv/kernel/smp.c            |  11 ++-
>  arch/riscv/kernel/traps.c          |   2 -
>  drivers/clocksource/timer-riscv.c  |  79 +++++++++++------
>  drivers/irqchip/Kconfig            |  13 +++
>  drivers/irqchip/Makefile           |   1 +
>  drivers/irqchip/irq-riscv-intc.c   | 134 +++++++++++++++++++++++++++++
>  drivers/irqchip/irq-sifive-plic.c  |  40 ++++-----
>  include/linux/cpuhotplug.h         |   1 +
>  15 files changed, 256 insertions(+), 88 deletions(-)
>  create mode 100644 drivers/irqchip/irq-riscv-intc.c
>
> --
> 2.17.1
>