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 */ 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 */ 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 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 75 void do_softirq_own_stack(void) 76 { 77 run_on_irqstack_cond(__do_softirq, NULL); 78 } 79