cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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irq.c (3083B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *	linux/arch/alpha/kernel/irq.c
      4 *
      5 *	Copyright (C) 1995 Linus Torvalds
      6 *
      7 * This file contains the code used by various IRQ handling routines:
      8 * asking for different IRQ's should be done through these routines
      9 * instead of just grabbing them. Thus setups with different IRQ numbers
     10 * shouldn't result in any weird surprises, and installing new handlers
     11 * should be easier.
     12 */
     13
     14#include <linux/kernel.h>
     15#include <linux/module.h>
     16#include <linux/errno.h>
     17#include <linux/kernel_stat.h>
     18#include <linux/signal.h>
     19#include <linux/sched.h>
     20#include <linux/ptrace.h>
     21#include <linux/interrupt.h>
     22#include <linux/random.h>
     23#include <linux/irq.h>
     24#include <linux/proc_fs.h>
     25#include <linux/seq_file.h>
     26#include <linux/profile.h>
     27#include <linux/bitops.h>
     28
     29#include <asm/io.h>
     30#include <linux/uaccess.h>
     31
     32volatile unsigned long irq_err_count;
     33DEFINE_PER_CPU(unsigned long, irq_pmi_count);
     34
     35void ack_bad_irq(unsigned int irq)
     36{
     37	irq_err_count++;
     38	printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
     39}
     40
     41#ifdef CONFIG_SMP 
     42static char irq_user_affinity[NR_IRQS];
     43
     44int irq_select_affinity(unsigned int irq)
     45{
     46	struct irq_data *data = irq_get_irq_data(irq);
     47	struct irq_chip *chip;
     48	static int last_cpu;
     49	int cpu = last_cpu + 1;
     50
     51	if (!data)
     52		return 1;
     53	chip = irq_data_get_irq_chip(data);
     54
     55	if (!chip->irq_set_affinity || irq_user_affinity[irq])
     56		return 1;
     57
     58	while (!cpu_possible(cpu) ||
     59	       !cpumask_test_cpu(cpu, irq_default_affinity))
     60		cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
     61	last_cpu = cpu;
     62
     63	cpumask_copy(irq_data_get_affinity_mask(data), cpumask_of(cpu));
     64	chip->irq_set_affinity(data, cpumask_of(cpu), false);
     65	return 0;
     66}
     67#endif /* CONFIG_SMP */
     68
     69int arch_show_interrupts(struct seq_file *p, int prec)
     70{
     71	int j;
     72
     73#ifdef CONFIG_SMP
     74	seq_puts(p, "IPI: ");
     75	for_each_online_cpu(j)
     76		seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
     77	seq_putc(p, '\n');
     78#endif
     79	seq_puts(p, "PMI: ");
     80	for_each_online_cpu(j)
     81		seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
     82	seq_puts(p, "          Performance Monitoring\n");
     83	seq_printf(p, "ERR: %10lu\n", irq_err_count);
     84	return 0;
     85}
     86
     87/*
     88 * handle_irq handles all normal device IRQ's (the special
     89 * SMP cross-CPU interrupts have their own specific
     90 * handlers).
     91 */
     92
     93#define MAX_ILLEGAL_IRQS 16
     94
     95void
     96handle_irq(int irq)
     97{	
     98	/* 
     99	 * We ack quickly, we don't want the irq controller
    100	 * thinking we're snobs just because some other CPU has
    101	 * disabled global interrupts (we have already done the
    102	 * INT_ACK cycles, it's too late to try to pretend to the
    103	 * controller that we aren't taking the interrupt).
    104	 *
    105	 * 0 return value means that this irq is already being
    106	 * handled by some other CPU. (or is disabled)
    107	 */
    108	static unsigned int illegal_count=0;
    109	struct irq_desc *desc = irq_to_desc(irq);
    110	
    111	if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
    112	    illegal_count < MAX_ILLEGAL_IRQS)) {
    113		irq_err_count++;
    114		illegal_count++;
    115		printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
    116		       irq);
    117		return;
    118	}
    119
    120	irq_enter();
    121	generic_handle_irq_desc(desc);
    122	irq_exit();
    123}