1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 *	Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
 4 *
 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
 9 * io_apic.c.)
10 */
11
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>
21
22#include <asm/cpu_entry_area.h>
23#include <asm/io_apic.h>
 
24#include <asm/apic.h>
25
26DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
27DECLARE_INIT_PER_CPU(irq_stack_backing_store);
 
 
 
28
29#ifdef CONFIG_VMAP_STACK
30/*
31 * VMAP the backing store with guard pages
 
 
 
 
32 */
33static int map_irq_stack(unsigned int cpu)
34{
35	char *stack = (char *)per_cpu_ptr(&irq_stack_backing_store, cpu);
36	struct page *pages[IRQ_STACK_SIZE / PAGE_SIZE];
37	void *va;
38	int i;
39
40	for (i = 0; i < IRQ_STACK_SIZE / PAGE_SIZE; i++) {
41		phys_addr_t pa = per_cpu_ptr_to_phys(stack + (i << PAGE_SHIFT));
42
43		pages[i] = pfn_to_page(pa >> PAGE_SHIFT);
44	}
45
46	va = vmap(pages, IRQ_STACK_SIZE / PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
47	if (!va)
48		return -ENOMEM;
49
50	per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
51	return 0;
52}
53#else
54/*
55 * If VMAP stacks are disabled due to KASAN, just use the per cpu
56 * backing store without guard pages.
57 */
58static int map_irq_stack(unsigned int cpu)
59{
60	void *va = per_cpu_ptr(&irq_stack_backing_store, cpu);
 
 
 
 
 
 
61
62	per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
63	return 0;
64}
65#endif
66
67int irq_init_percpu_irqstack(unsigned int cpu)
 
 
 
68{
69	if (per_cpu(hardirq_stack_ptr, cpu))
70		return 0;
71	return map_irq_stack(cpu);
 
 
 
 
 
 
 
 
 
 
 
72}

 
 1/*
 2 *	Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
 3 *
 4 * This file contains the lowest level x86_64-specific interrupt
 5 * entry and irq statistics code. All the remaining irq logic is
 6 * done by the generic kernel/irq/ code and in the
 7 * x86_64-specific irq controller code. (e.g. i8259.c and
 8 * io_apic.c.)
 9 */
10
11#include <linux/kernel_stat.h>
12#include <linux/interrupt.h>
 
13#include <linux/seq_file.h>
14#include <linux/module.h>
15#include <linux/delay.h>
16#include <linux/ftrace.h>
17#include <linux/uaccess.h>
18#include <linux/smp.h>
 
 
 
19#include <asm/io_apic.h>
20#include <asm/idle.h>
21#include <asm/apic.h>
22
23DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
24EXPORT_PER_CPU_SYMBOL(irq_stat);
25
26DEFINE_PER_CPU(struct pt_regs *, irq_regs);
27EXPORT_PER_CPU_SYMBOL(irq_regs);
28
 
29/*
30 * Probabilistic stack overflow check:
31 *
32 * Only check the stack in process context, because everything else
33 * runs on the big interrupt stacks. Checking reliably is too expensive,
34 * so we just check from interrupts.
35 */
36static inline void stack_overflow_check(struct pt_regs *regs)
37{
38#ifdef CONFIG_DEBUG_STACKOVERFLOW
39	u64 curbase = (u64)task_stack_page(current);
 
 
40
41	WARN_ONCE(regs->sp >= curbase &&
42		  regs->sp <= curbase + THREAD_SIZE &&
43		  regs->sp <  curbase + sizeof(struct thread_info) +
44					sizeof(struct pt_regs) + 128,
 
45
46		  "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
47			current->comm, curbase, regs->sp);
48#endif
 
 
 
49}
50
51bool handle_irq(unsigned irq, struct pt_regs *regs)
 
 
 
 
52{
53	struct irq_desc *desc;
54
55	stack_overflow_check(regs);
56
57	desc = irq_to_desc(irq);
58	if (unlikely(!desc))
59		return false;
60
61	generic_handle_irq_desc(irq, desc);
62	return true;
63}
 
64
65
66extern void call_softirq(void);
67
68asmlinkage void do_softirq(void)
69{
70	__u32 pending;
71	unsigned long flags;
72
73	if (in_interrupt())
74		return;
75
76	local_irq_save(flags);
77	pending = local_softirq_pending();
78	/* Switch to interrupt stack */
79	if (pending) {
80		call_softirq();
81		WARN_ON_ONCE(softirq_count());
82	}
83	local_irq_restore(flags);
84}