1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Based on arch/arm/kernel/irq.c 4 * 5 * Copyright (C) 1992 Linus Torvalds 6 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. 7 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation. 8 * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and 9 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>. 10 * Copyright (C) 2012 ARM Ltd. 11 */ 12 13#include <linux/hardirq.h> 14#include <linux/init.h> 15#include <linux/irq.h> 16#include <linux/irqchip.h> 17#include <linux/kprobes.h> 18#include <linux/memory.h> 19#include <linux/scs.h> 20#include <linux/seq_file.h> 21#include <linux/smp.h> 22#include <linux/vmalloc.h> 23#include <asm/daifflags.h> 24#include <asm/exception.h> 25#include <asm/numa.h> 26#include <asm/softirq_stack.h> 27#include <asm/stacktrace.h> 28#include <asm/vmap_stack.h> 29 30/* Only access this in an NMI enter/exit */ 31DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); 32 33DEFINE_PER_CPU(unsigned long *, irq_stack_ptr); 34 35 36DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); 37 38#ifdef CONFIG_SHADOW_CALL_STACK 39DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); 40#endif 41 42static void init_irq_scs(void) 43{ 44 int cpu; 45 46 if (!scs_is_enabled()) 47 return; 48 49 for_each_possible_cpu(cpu) 50 per_cpu(irq_shadow_call_stack_ptr, cpu) = 51 scs_alloc(early_cpu_to_node(cpu)); 52} 53 54#ifdef CONFIG_VMAP_STACK 55static void __init init_irq_stacks(void) 56{ 57 int cpu; 58 unsigned long *p; 59 60 for_each_possible_cpu(cpu) { 61 p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, early_cpu_to_node(cpu)); 62 per_cpu(irq_stack_ptr, cpu) = p; 63 } 64} 65#else 66/* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */ 67DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack); 68 69static void init_irq_stacks(void) 70{ 71 int cpu; 72 73 for_each_possible_cpu(cpu) 74 per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu); 75} 76#endif 77 78#ifndef CONFIG_PREEMPT_RT 79static void ____do_softirq(struct pt_regs *regs) 80{ 81 __do_softirq(); 82} 83 84void do_softirq_own_stack(void) 85{ 86 call_on_irq_stack(NULL, ____do_softirq); 87} 88#endif 89 90static void default_handle_irq(struct pt_regs *regs) 91{ 92 panic("IRQ taken without a root IRQ handler\n"); 93} 94 95static void default_handle_fiq(struct pt_regs *regs) 96{ 97 panic("FIQ taken without a root FIQ handler\n"); 98} 99 100void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq; 101void (*handle_arch_fiq)(struct pt_regs *) __ro_after_init = default_handle_fiq; 102 103int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) 104{ 105 if (handle_arch_irq != default_handle_irq) 106 return -EBUSY; 107 108 handle_arch_irq = handle_irq; 109 pr_info("Root IRQ handler: %ps\n", handle_irq); 110 return 0; 111} 112 113int __init set_handle_fiq(void (*handle_fiq)(struct pt_regs *)) 114{ 115 if (handle_arch_fiq != default_handle_fiq) 116 return -EBUSY; 117 118 handle_arch_fiq = handle_fiq; 119 pr_info("Root FIQ handler: %ps\n", handle_fiq); 120 return 0; 121} 122 123void __init init_IRQ(void) 124{ 125 init_irq_stacks(); 126 init_irq_scs(); 127 irqchip_init(); 128 129 if (system_uses_irq_prio_masking()) { 130 /* 131 * Now that we have a stack for our IRQ handler, set 132 * the PMR/PSR pair to a consistent state. 133 */ 134 WARN_ON(read_sysreg(daif) & PSR_A_BIT); 135 local_daif_restore(DAIF_PROCCTX_NOIRQ); 136 } 137} 138