From 0ac26104208450d35c4e68754ce0c67b3a4d7802 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 14 Apr 2019 18:00:05 +0200 Subject: [PATCH] x86/irq/64: Init hardirq_stack_ptr during CPU hotplug Preparatory change for disentangling the irq stack union as a prerequisite for irq stacks with guard pages. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: "Chang S. Bae" Cc: Dominik Brodowski Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: Konrad Rzeszutek Wilk Cc: Nicolai Stange Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Sean Christopherson Cc: x86-ml Cc: Yi Wang Link: https://lkml.kernel.org/r/20190414160146.177558566@linutronix.de --- arch/x86/include/asm/irq.h | 4 ---- arch/x86/kernel/cpu/common.c | 4 +--- arch/x86/kernel/irq_64.c | 15 +++++++++++++++ 3 files changed, 16 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h index d751e8440a6b..8f95686ec27e 100644 --- a/arch/x86/include/asm/irq.h +++ b/arch/x86/include/asm/irq.h @@ -16,11 +16,7 @@ static inline int irq_canonicalize(int irq) return ((irq == 2) ? 9 : irq); } -#ifdef CONFIG_X86_32 extern int irq_init_percpu_irqstack(unsigned int cpu); -#else -static inline int irq_init_percpu_irqstack(unsigned int cpu) { return 0; } -#endif #define __ARCH_HAS_DO_SOFTIRQ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 13ec72bb8f36..1222080838da 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1510,9 +1510,7 @@ DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned = &init_task; EXPORT_PER_CPU_SYMBOL(current_task); -DEFINE_PER_CPU(char *, hardirq_stack_ptr) = - init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE; - +DEFINE_PER_CPU(char *, hardirq_stack_ptr); DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1; DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT; diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index f0c7356c8969..c0bea0d7d76a 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -87,3 +87,18 @@ bool handle_irq(struct irq_desc *desc, struct pt_regs *regs) generic_handle_irq_desc(desc); return true; } + +static int map_irq_stack(unsigned int cpu) +{ + void *va = per_cpu_ptr(irq_stack_union.irq_stack, cpu); + + per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE; + return 0; +} + +int irq_init_percpu_irqstack(unsigned int cpu) +{ + if (per_cpu(hardirq_stack_ptr, cpu)) + return 0; + return map_irq_stack(cpu); +} -- 2.30.2