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

From: Anup Patel
Date: Mon Mar 09 2020 - 07:57:35 EST


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
>