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

[Anup Patel]

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