From ada68a66b72687e6b74e35c42efd1783e84b01fd Mon Sep 17 00:00:00 2001 From: Mahesh Salgaonkar Date: Tue, 23 Jun 2020 15:57:50 +0530 Subject: powerpc/64s: Move HMI IRQ stat from percpu variable to paca. With the proposed change in percpu bootmem allocator to use page mapping [1], the percpu first chunk memory area can come from vmalloc ranges. This makes the HMI (Hypervisor Maintenance Interrupt) handler crash the kernel whenever percpu variable is accessed in real mode. This patch fixes this issue by moving the HMI IRQ stat inside paca for safe access in realmode. [1] https://lore.kernel.org/linuxppc-dev/20200608070904.387440-1-aneesh.kumar@linux.ibm.com/ Suggested-by: Aneesh Kumar K.V Signed-off-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/159290806973.3642154.5244613424529764050.stgit@jupiter --- arch/powerpc/kernel/irq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'arch/powerpc/kernel/irq.c') diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 05b1cc0e009e..bf21ebd36190 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -621,13 +621,14 @@ int arch_show_interrupts(struct seq_file *p, int prec) seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions); seq_printf(p, " Machine check exceptions\n"); +#ifdef CONFIG_PPC_BOOK3S_64 if (cpu_has_feature(CPU_FTR_HVMODE)) { seq_printf(p, "%*s: ", prec, "HMI"); for_each_online_cpu(j) - seq_printf(p, "%10u ", - per_cpu(irq_stat, j).hmi_exceptions); + seq_printf(p, "%10u ", paca_ptrs[j]->hmi_irqs); seq_printf(p, " Hypervisor Maintenance Interrupts\n"); } +#endif seq_printf(p, "%*s: ", prec, "NMI"); for_each_online_cpu(j) @@ -665,7 +666,9 @@ u64 arch_irq_stat_cpu(unsigned int cpu) sum += per_cpu(irq_stat, cpu).mce_exceptions; sum += per_cpu(irq_stat, cpu).spurious_irqs; sum += per_cpu(irq_stat, cpu).timer_irqs_others; - sum += per_cpu(irq_stat, cpu).hmi_exceptions; +#ifdef CONFIG_PPC_BOOK3S_64 + sum += paca_ptrs[cpu]->hmi_irqs; +#endif sum += per_cpu(irq_stat, cpu).sreset_irqs; #ifdef CONFIG_PPC_WATCHDOG sum += per_cpu(irq_stat, cpu).soft_nmi_irqs; -- cgit v1.2.1