mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
e20800fd5c
Linux has expected that interrupt handlers are executed with local
interrupts disabled for a while now, so ensure that this is the case on
Alpha even for non-device interrupts such as IPIs.
Without this patch, secondary boot results in the following backtrace:
warning: at kernel/softirq.c:139 __local_bh_enable+0xb8/0xd0()
trace:
__local_bh_enable+0xb8/0xd0
irq_enter+0x74/0xa0
scheduler_ipi+0x50/0x100
handle_ipi+0x84/0x260
do_entint+0x1ac/0x2e0
irq_exit+0x60/0xa0
handle_irq+0x98/0x100
do_entint+0x2c8/0x2e0
ret_from_sys_call+0x0/0x10
load_balance+0x3e4/0x870
cpu_idle+0x24/0x80
rcu_eqs_enter_common.isra.38+0x0/0x120
cpu_idle+0x40/0x80
rest_init+0xc0/0xe0
_stext+0x1c/0x20
A similar dump occurs if you try to reboot using magic-sysrq.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
123 lines
3 KiB
C
123 lines
3 KiB
C
/*
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* linux/arch/alpha/kernel/irq.c
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*
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* Copyright (C) 1995 Linus Torvalds
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*
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* This file contains the code used by various IRQ handling routines:
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* asking for different IRQ's should be done through these routines
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* instead of just grabbing them. Thus setups with different IRQ numbers
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* shouldn't result in any weird surprises, and installing new handlers
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* should be easier.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/kernel_stat.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/ptrace.h>
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#include <linux/interrupt.h>
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#include <linux/random.h>
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#include <linux/init.h>
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#include <linux/irq.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/profile.h>
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#include <linux/bitops.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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volatile unsigned long irq_err_count;
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DEFINE_PER_CPU(unsigned long, irq_pmi_count);
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void ack_bad_irq(unsigned int irq)
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{
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irq_err_count++;
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printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
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}
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#ifdef CONFIG_SMP
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static char irq_user_affinity[NR_IRQS];
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int irq_select_affinity(unsigned int irq)
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{
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struct irq_data *data = irq_get_irq_data(irq);
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struct irq_chip *chip;
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static int last_cpu;
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int cpu = last_cpu + 1;
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if (!data)
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return 1;
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chip = irq_data_get_irq_chip(data);
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if (!chip->irq_set_affinity || irq_user_affinity[irq])
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return 1;
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while (!cpu_possible(cpu) ||
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!cpumask_test_cpu(cpu, irq_default_affinity))
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cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
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last_cpu = cpu;
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cpumask_copy(data->affinity, cpumask_of(cpu));
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chip->irq_set_affinity(data, cpumask_of(cpu), false);
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return 0;
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}
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#endif /* CONFIG_SMP */
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int arch_show_interrupts(struct seq_file *p, int prec)
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{
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int j;
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#ifdef CONFIG_SMP
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seq_puts(p, "IPI: ");
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for_each_online_cpu(j)
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seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
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seq_putc(p, '\n');
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#endif
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seq_puts(p, "PMI: ");
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for_each_online_cpu(j)
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seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
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seq_puts(p, " Performance Monitoring\n");
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seq_printf(p, "ERR: %10lu\n", irq_err_count);
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return 0;
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}
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/*
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* handle_irq handles all normal device IRQ's (the special
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* SMP cross-CPU interrupts have their own specific
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* handlers).
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*/
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#define MAX_ILLEGAL_IRQS 16
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void
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handle_irq(int irq)
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{
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/*
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* We ack quickly, we don't want the irq controller
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* thinking we're snobs just because some other CPU has
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* disabled global interrupts (we have already done the
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* INT_ACK cycles, it's too late to try to pretend to the
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* controller that we aren't taking the interrupt).
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*
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* 0 return value means that this irq is already being
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* handled by some other CPU. (or is disabled)
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*/
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static unsigned int illegal_count=0;
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struct irq_desc *desc = irq_to_desc(irq);
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if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
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illegal_count < MAX_ILLEGAL_IRQS)) {
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irq_err_count++;
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illegal_count++;
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printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
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irq);
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return;
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}
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irq_enter();
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generic_handle_irq_desc(irq, desc);
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irq_exit();
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}
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