1 /* 2 * Based on arch/arm/kernel/irq.c 3 * 4 * Copyright (C) 1992 Linus Torvalds 5 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. 6 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation. 7 * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and 8 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>. 9 * Copyright (C) 2012 ARM Ltd. 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program. If not, see <http://www.gnu.org/licenses/>. 22 */ 23 24 #include <linux/kernel_stat.h> 25 #include <linux/irq.h> 26 #include <linux/memory.h> 27 #include <linux/smp.h> 28 #include <linux/init.h> 29 #include <linux/irqchip.h> 30 #include <linux/kprobes.h> 31 #include <linux/seq_file.h> 32 #include <linux/vmalloc.h> 33 #include <asm/daifflags.h> 34 #include <asm/vmap_stack.h> 35 36 unsigned long irq_err_count; 37 38 /* Only access this in an NMI enter/exit */ 39 DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); 40 41 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr); 42 43 int arch_show_interrupts(struct seq_file *p, int prec) 44 { 45 show_ipi_list(p, prec); 46 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); 47 return 0; 48 } 49 50 #ifdef CONFIG_VMAP_STACK 51 static void init_irq_stacks(void) 52 { 53 int cpu; 54 unsigned long *p; 55 56 for_each_possible_cpu(cpu) { 57 p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu)); 58 per_cpu(irq_stack_ptr, cpu) = p; 59 } 60 } 61 #else 62 /* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */ 63 DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack); 64 65 static void init_irq_stacks(void) 66 { 67 int cpu; 68 69 for_each_possible_cpu(cpu) 70 per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu); 71 } 72 #endif 73 74 void __init init_IRQ(void) 75 { 76 init_irq_stacks(); 77 irqchip_init(); 78 if (!handle_arch_irq) 79 panic("No interrupt controller found."); 80 81 if (system_uses_irq_prio_masking()) { 82 /* 83 * Now that we have a stack for our IRQ handler, set 84 * the PMR/PSR pair to a consistent state. 85 */ 86 WARN_ON(read_sysreg(daif) & PSR_A_BIT); 87 local_daif_restore(DAIF_PROCCTX_NOIRQ); 88 } 89 } 90 91 /* 92 * Stubs to make nmi_enter/exit() code callable from ASM 93 */ 94 asmlinkage void notrace asm_nmi_enter(void) 95 { 96 nmi_enter(); 97 } 98 NOKPROBE_SYMBOL(asm_nmi_enter); 99 100 asmlinkage void notrace asm_nmi_exit(void) 101 { 102 nmi_exit(); 103 } 104 NOKPROBE_SYMBOL(asm_nmi_exit); 105