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 */ 31 DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); 32 33 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr); 34 35 36 DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); 37 38 #ifdef CONFIG_SHADOW_CALL_STACK 39 DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); 40 #endif 41 42 static 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(cpu_to_node(cpu)); 52 } 53 54 #ifdef CONFIG_VMAP_STACK 55 static 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. */ 67 DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack); 68 69 static 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 79 static void ____do_softirq(struct pt_regs *regs) 80 { 81 __do_softirq(); 82 } 83 84 void do_softirq_own_stack(void) 85 { 86 call_on_irq_stack(NULL, ____do_softirq); 87 } 88 #endif 89 90 static void default_handle_irq(struct pt_regs *regs) 91 { 92 panic("IRQ taken without a root IRQ handler\n"); 93 } 94 95 static void default_handle_fiq(struct pt_regs *regs) 96 { 97 panic("FIQ taken without a root FIQ handler\n"); 98 } 99 100 void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq; 101 void (*handle_arch_fiq)(struct pt_regs *) __ro_after_init = default_handle_fiq; 102 103 int __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 } 112 113 int __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 } 122 123 void __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