[PATCH v3 0/4] New RISC-V Local Interrupt Controller Driver

From: Anup Patel
Date: Wed Feb 19 2020 - 12:16:01 EST


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 having this new driver are as follows:
1. It registers all local interrupts as per-CPU interrupts
2. We can develop drivers for devices with per-CPU local interrupts
without changing arch code or this driver
3. It allows local interrupt controller DT node under each CPU DT node
as well as single system-wide DT node for local interrupt controller.

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-rc2 and can be found at riscv_intc_v3
branch of: https://github.com/avpatel/linux.git

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 (4):
RISC-V: self-contained IPI handling routine
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/smp.h | 3 +
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 | 131 ++++++++++++++++++++++++++++++
drivers/irqchip/irq-sifive-plic.c | 39 ++++++++-
include/linux/cpuhotplug.h | 2 +
13 files changed, 252 insertions(+), 72 deletions(-)
create mode 100644 drivers/irqchip/irq-riscv-intc.c

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2.17.1