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/irq.h> 14 #include <linux/memory.h> 15 #include <linux/smp.h> 16 #include <linux/hardirq.h> 17 #include <linux/init.h> 18 #include <linux/irqchip.h> 19 #include <linux/kprobes.h> 20 #include <linux/seq_file.h> 21 #include <linux/vmalloc.h> 22 #include <asm/daifflags.h> 23 #include <asm/vmap_stack.h> 24 25 /* Only access this in an NMI enter/exit */ 26 DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); 27 28 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr); 29 30 #ifdef CONFIG_VMAP_STACK 31 static void init_irq_stacks(void) 32 { 33 int cpu; 34 unsigned long *p; 35 36 for_each_possible_cpu(cpu) { 37 p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu)); 38 per_cpu(irq_stack_ptr, cpu) = p; 39 } 40 } 41 #else 42 /* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */ 43 DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack); 44 45 static void init_irq_stacks(void) 46 { 47 int cpu; 48 49 for_each_possible_cpu(cpu) 50 per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu); 51 } 52 #endif 53 54 void __init init_IRQ(void) 55 { 56 init_irq_stacks(); 57 irqchip_init(); 58 if (!handle_arch_irq) 59 panic("No interrupt controller found."); 60 61 if (system_uses_irq_prio_masking()) { 62 /* 63 * Now that we have a stack for our IRQ handler, set 64 * the PMR/PSR pair to a consistent state. 65 */ 66 WARN_ON(read_sysreg(daif) & PSR_A_BIT); 67 local_daif_restore(DAIF_PROCCTX_NOIRQ); 68 } 69 } 70 71 /* 72 * Stubs to make nmi_enter/exit() code callable from ASM 73 */ 74 asmlinkage void notrace asm_nmi_enter(void) 75 { 76 nmi_enter(); 77 } 78 NOKPROBE_SYMBOL(asm_nmi_enter); 79 80 asmlinkage void notrace asm_nmi_exit(void) 81 { 82 nmi_exit(); 83 } 84 NOKPROBE_SYMBOL(asm_nmi_exit); 85