Messages in this thread | | | From | Anup Patel <> | Subject | [PATCH v6 0/6] New RISC-V Local Interrupt Controller Driver | Date | Sat, 30 May 2020 15:37:19 +0530 |
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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. All local interrupts are registered as per-CPU interrupts 2. The RISC-V timer driver can register timer interrupt handler using kernel irq subsystem without relying on arch/riscv to explicitly call it's interrupt handler 3. 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 4. In future, we can develop drivers for devices with per-HART interrupts without changing arch code or this driver (example, CLINT timer driver for RISC-V M-mode kernel)
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-5.7-rc7 and can be found at riscv_intc_v6 branch of: https://github.com/avpatel/linux.git
This series is tested on: 1. QEMU RV64 virt machine using Linux RISC-V S-mode 2. QEMU RV32 virt machine using Linux RISC-V S-mode 3. QEMU RV64 virt machine using Linux RISC-V M-mode (i.e. NoMMU)
Changes since v5: - Rebased to Linux-5.7-rc7 with PLIC improvement patches - Removed riscv_of_parent_hartid() from PATCH3 - Addressed other minor comments from Palmer and Marc Z
Changes since v4: - Rebased to Linux-5.7-rc6 and multi-PLIC improvement patches - Added separate patch to force select RISCV_INTC for CONFIG_RISCV - Fixed the driver for Linux RISC-V NoMMU
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 (6): 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/drivers/timer-riscv: Use per-CPU timer interrupt RISC-V: Remove do_IRQ() function RISC-V: Force select RISCV_INTC for CONFIG_RISCV
arch/riscv/Kconfig | 2 + 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 | 41 ++++++++- drivers/irqchip/Kconfig | 13 +++ drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-riscv-intc.c | 140 +++++++++++++++++++++++++++++ drivers/irqchip/irq-sifive-plic.c | 44 ++++----- include/linux/cpuhotplug.h | 1 + 15 files changed, 253 insertions(+), 64 deletions(-) create mode 100644 drivers/irqchip/irq-riscv-intc.c
-- 2.25.1
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