1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
5 * This file contains the lowest level x86_64-specific interrupt
6 * entry and irq statistics code. All the remaining irq logic is
7 * done by the generic kernel/irq/ code and in the
8 * x86_64-specific irq controller code. (e.g. i8259.c and
12 #include <linux/kernel_stat.h>
13 #include <linux/interrupt.h>
14 #include <linux/irq.h>
15 #include <linux/seq_file.h>
16 #include <linux/delay.h>
17 #include <linux/ftrace.h>
18 #include <linux/uaccess.h>
19 #include <linux/smp.h>
20 #include <linux/sched/task_stack.h>
22 #include <asm/cpu_entry_area.h>
23 #include <asm/io_apic.h>
26 DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
27 DECLARE_INIT_PER_CPU(irq_stack_backing_store);
29 bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
31 if (IS_ERR_OR_NULL(desc))
34 generic_handle_irq_desc(desc);
38 #ifdef CONFIG_VMAP_STACK
40 * VMAP the backing store with guard pages
42 static int map_irq_stack(unsigned int cpu)
44 char *stack = (char *)per_cpu_ptr(&irq_stack_backing_store, cpu);
45 struct page *pages[IRQ_STACK_SIZE / PAGE_SIZE];
49 for (i = 0; i < IRQ_STACK_SIZE / PAGE_SIZE; i++) {
50 phys_addr_t pa = per_cpu_ptr_to_phys(stack + (i << PAGE_SHIFT));
52 pages[i] = pfn_to_page(pa >> PAGE_SHIFT);
55 va = vmap(pages, IRQ_STACK_SIZE / PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
59 per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
64 * If VMAP stacks are disabled due to KASAN, just use the per cpu
65 * backing store without guard pages.
67 static int map_irq_stack(unsigned int cpu)
69 void *va = per_cpu_ptr(&irq_stack_backing_store, cpu);
71 per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
76 int irq_init_percpu_irqstack(unsigned int cpu)
78 if (per_cpu(hardirq_stack_ptr, cpu))
80 return map_irq_stack(cpu);