[Crash-utility] [PATCH V5 1/2] riscv: kexec: Fixup irq controller broken in kexec crash path

From: Guo Ren <guoren(a)linux.alibaba.com&gt; If a crash happens on cpu3 and all interrupts are binding on cpu0, the bad irq routing will cause a crash kernel which can't receive any irq. Because crash kernel won't clean up all harts' PLIC enable bits in enable registers. This patch is similar to 9141a003a491 ("ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path") and 78fd584cdec0 ("arm64: kdump: implement machine_crash_shutdown()"), and PowerPC also has the same mechanism. Fixes: fba8a8674f68 ("RISC-V: Add kexec support") Signed-off-by: Guo Ren <guoren(a)linux.alibaba.com&gt; Signed-off-by: Guo Ren <guoren(a)kernel.org&gt; Reviewed-by: Xianting Tian <xianting.tian(a)linux.alibaba.com&gt; Cc: Nick Kossifidis <mick(a)ics.forth.gr&gt; Cc: Palmer Dabbelt <palmer(a)rivosinc.com&gt; --- arch/riscv/kernel/machine_kexec.c | 35 +++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c index ee79e6839b86..db41c676e5a2 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -15,6 +15,8 @@ #include <linux/compiler.h> /* For unreachable() */ #include <linux/cpu.h> /* For cpu_down() */ #include <linux/reboot.h> +#include <linux/interrupt.h> +#include <linux/irq.h> /* * kexec_image_info - Print received image details @@ -154,6 +156,37 @@ void crash_smp_send_stop(void) cpus_stopped = 1; } +static void machine_kexec_mask_interrupts(void) +{ + unsigned int i; + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { + struct irq_chip *chip; + int ret; + + chip = irq_desc_get_chip(desc); + if (!chip) + continue; + + /* + * First try to remove the active state. If this + * fails, try to EOI the interrupt. + */ + ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false); + + if (ret && irqd_irq_inprogress(&desc->irq_data) && + chip->irq_eoi) + chip->irq_eoi(&desc->irq_data); + + if (chip->irq_mask) + chip->irq_mask(&desc->irq_data); + + if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) + chip->irq_disable(&desc->irq_data); + } +} + /* * machine_crash_shutdown - Prepare to kexec after a kernel crash * @@ -169,6 +202,8 @@ machine_crash_shutdown(struct pt_regs *regs) crash_smp_send_stop(); crash_save_cpu(regs, smp_processor_id()); + machine_kexec_mask_interrupts(); + pr_info("Starting crashdump kernel...\n"); } -- 2.36.1