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/irq_stack.h>
24 #include <asm/io_apic.h>
25 #include <asm/apic.h>
26
27 DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
28 DECLARE_INIT_PER_CPU(irq_stack_backing_store);
29
30 #ifdef CONFIG_VMAP_STACK
31 /*
32 * VMAP the backing store with guard pages
33 */
map_irq_stack(unsigned int cpu)34 static int map_irq_stack(unsigned int cpu)
35 {
36 char *stack = (char *)per_cpu_ptr(&irq_stack_backing_store, cpu);
37 struct page *pages[IRQ_STACK_SIZE / PAGE_SIZE];
38 void *va;
39 int i;
40
41 for (i = 0; i < IRQ_STACK_SIZE / PAGE_SIZE; i++) {
42 phys_addr_t pa = per_cpu_ptr_to_phys(stack + (i << PAGE_SHIFT));
43
44 pages[i] = pfn_to_page(pa >> PAGE_SHIFT);
45 }
46
47 va = vmap(pages, IRQ_STACK_SIZE / PAGE_SIZE, VM_MAP, PAGE_KERNEL);
48 if (!va)
49 return -ENOMEM;
50
51 per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
52 return 0;
53 }
54 #else
55 /*
56 * If VMAP stacks are disabled due to KASAN, just use the per cpu
57 * backing store without guard pages.
58 */
map_irq_stack(unsigned int cpu)59 static int map_irq_stack(unsigned int cpu)
60 {
61 void *va = per_cpu_ptr(&irq_stack_backing_store, cpu);
62
63 per_cpu(hardirq_stack_ptr, cpu) = va + IRQ_STACK_SIZE;
64 return 0;
65 }
66 #endif
67
irq_init_percpu_irqstack(unsigned int cpu)68 int irq_init_percpu_irqstack(unsigned int cpu)
69 {
70 if (per_cpu(hardirq_stack_ptr, cpu))
71 return 0;
72 return map_irq_stack(cpu);
73 }
74
do_softirq_own_stack(void)75 void do_softirq_own_stack(void)
76 {
77 run_on_irqstack_cond(__do_softirq, NULL);
78 }
79
