1 // SPDX-License-Identifier: GPL-2.0 !! 1 /*
2 // Copyright (C) 2018 Hangzhou C-SKY Microsyst !! 2 * This file is subject to the terms and conditions of the GNU General Public
3 !! 3 * License. See the file "COPYING" in the main directory of this archive
>> 4 * for more details.
>> 5 *
>> 6 * Code to handle x86 style IRQs plus some generic interrupt stuff.
>> 7 *
>> 8 * Copyright (C) 1992 Linus Torvalds
>> 9 * Copyright (C) 1994 - 2000 Ralf Baechle
>> 10 */
>> 11 #include <linux/kernel.h>
>> 12 #include <linux/delay.h>
4 #include <linux/init.h> 13 #include <linux/init.h>
5 #include <linux/interrupt.h> 14 #include <linux/interrupt.h>
6 #include <linux/irq.h> !! 15 #include <linux/kernel_stat.h>
7 #include <linux/irqchip.h> !! 16 #include <linux/proc_fs.h>
8 #include <asm/traps.h> !! 17 #include <linux/mm.h>
9 #include <asm/smp.h> !! 18 #include <linux/random.h>
>> 19 #include <linux/sched.h>
>> 20 #include <linux/seq_file.h>
>> 21 #include <linux/kallsyms.h>
>> 22 #include <linux/kgdb.h>
>> 23 #include <linux/ftrace.h>
>> 24
>> 25 #include <linux/atomic.h>
>> 26 #include <asm/uaccess.h>
>> 27
>> 28 #ifdef CONFIG_KGDB
>> 29 int kgdb_early_setup;
>> 30 #endif
>> 31
>> 32 static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
>> 33
>> 34 int allocate_irqno(void)
>> 35 {
>> 36 int irq;
>> 37
>> 38 again:
>> 39 irq = find_first_zero_bit(irq_map, NR_IRQS);
>> 40
>> 41 if (irq >= NR_IRQS)
>> 42 return -ENOSPC;
>> 43
>> 44 if (test_and_set_bit(irq, irq_map))
>> 45 goto again;
>> 46
>> 47 return irq;
>> 48 }
>> 49
>> 50 /*
>> 51 * Allocate the 16 legacy interrupts for i8259 devices. This happens early
>> 52 * in the kernel initialization so treating allocation failure as BUG() is
>> 53 * ok.
>> 54 */
>> 55 void __init alloc_legacy_irqno(void)
>> 56 {
>> 57 int i;
>> 58
>> 59 for (i = 0; i <= 16; i++)
>> 60 BUG_ON(test_and_set_bit(i, irq_map));
>> 61 }
>> 62
>> 63 void free_irqno(unsigned int irq)
>> 64 {
>> 65 smp_mb__before_clear_bit();
>> 66 clear_bit(irq, irq_map);
>> 67 smp_mb__after_clear_bit();
>> 68 }
>> 69
>> 70 /*
>> 71 * 'what should we do if we get a hw irq event on an illegal vector'.
>> 72 * each architecture has to answer this themselves.
>> 73 */
>> 74 void ack_bad_irq(unsigned int irq)
>> 75 {
>> 76 smtc_im_ack_irq(irq);
>> 77 printk("unexpected IRQ # %d\n", irq);
>> 78 }
>> 79
>> 80 atomic_t irq_err_count;
>> 81
>> 82 int arch_show_interrupts(struct seq_file *p, int prec)
>> 83 {
>> 84 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
>> 85 return 0;
>> 86 }
>> 87
>> 88 asmlinkage void spurious_interrupt(void)
>> 89 {
>> 90 atomic_inc(&irq_err_count);
>> 91 }
10 92
11 void __init init_IRQ(void) 93 void __init init_IRQ(void)
12 { 94 {
13 irqchip_init(); !! 95 int i;
14 #ifdef CONFIG_SMP !! 96
15 setup_smp_ipi(); !! 97 #ifdef CONFIG_KGDB
>> 98 if (kgdb_early_setup)
>> 99 return;
>> 100 #endif
>> 101
>> 102 for (i = 0; i < NR_IRQS; i++)
>> 103 irq_set_noprobe(i);
>> 104
>> 105 arch_init_irq();
>> 106
>> 107 #ifdef CONFIG_KGDB
>> 108 if (!kgdb_early_setup)
>> 109 kgdb_early_setup = 1;
>> 110 #endif
>> 111 }
>> 112
>> 113 #ifdef CONFIG_DEBUG_STACKOVERFLOW
>> 114 static inline void check_stack_overflow(void)
>> 115 {
>> 116 unsigned long sp;
>> 117
>> 118 __asm__ __volatile__("move %0, $sp" : "=r" (sp));
>> 119 sp &= THREAD_MASK;
>> 120
>> 121 /*
>> 122 * Check for stack overflow: is there less than STACK_WARN free?
>> 123 * STACK_WARN is defined as 1/8 of THREAD_SIZE by default.
>> 124 */
>> 125 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
>> 126 printk("do_IRQ: stack overflow: %ld\n",
>> 127 sp - sizeof(struct thread_info));
>> 128 dump_stack();
>> 129 }
>> 130 }
>> 131 #else
>> 132 static inline void check_stack_overflow(void) {}
16 #endif 133 #endif
>> 134
>> 135
>> 136 /*
>> 137 * do_IRQ handles all normal device IRQ's (the special
>> 138 * SMP cross-CPU interrupts have their own specific
>> 139 * handlers).
>> 140 */
>> 141 void __irq_entry do_IRQ(unsigned int irq)
>> 142 {
>> 143 irq_enter();
>> 144 check_stack_overflow();
>> 145 if (!smtc_handle_on_other_cpu(irq))
>> 146 generic_handle_irq(irq);
>> 147 irq_exit();
>> 148 }
>> 149
>> 150 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
>> 151 /*
>> 152 * To avoid inefficient and in some cases pathological re-checking of
>> 153 * IRQ affinity, we have this variant that skips the affinity check.
>> 154 */
>> 155
>> 156 void __irq_entry do_IRQ_no_affinity(unsigned int irq)
>> 157 {
>> 158 irq_enter();
>> 159 smtc_im_backstop(irq);
>> 160 generic_handle_irq(irq);
>> 161 irq_exit();
17 } 162 }
>> 163
>> 164 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
18 165
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