arch/arm/kernel/irq.c

   1 /*
   2  *  linux/arch/arm/kernel/irq.c
   3  *
   4  *  Copyright (C) 1992 Linus Torvalds
   5  *  Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
   6  *
   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  *
  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 file contains the code used by various IRQ handling routines:
  16  *  asking for different IRQ's should be done through these routines
  17  *  instead of just grabbing them. Thus setups with different IRQ numbers
  18  *  shouldn't result in any weird surprises, and installing new handlers
  19  *  should be easier.
  20  *
  21  *  IRQ's are in fact implemented a bit like signal handlers for the kernel.
  22  *  Naturally it's not a 1:1 relation, but there are similarities.
  23  */
  24 #include <linux/kernel_stat.h>
  25 #include <linux/signal.h>
  26 #include <linux/ioport.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29 #include <linux/irqchip.h>
  30 #include <linux/random.h>
  31 #include <linux/smp.h>
  32 #include <linux/init.h>
  33 #include <linux/seq_file.h>
  34 #include <linux/ratelimit.h>
  35 #include <linux/errno.h>
  36 #include <linux/list.h>
  37 #include <linux/kallsyms.h>
  38 #include <linux/proc_fs.h>
  39 #include <linux/export.h>
  40
  41 #include <asm/hardware/cache-l2x0.h>
  42 #include <asm/exception.h>
  43 #include <asm/mach/arch.h>
  44 #include <asm/mach/irq.h>
  45 #include <asm/mach/time.h>
  46
  47 unsigned long irq_err_count;
  48
  49 int arch_show_interrupts(struct seq_file *p, int prec)
  50 {
  51 #ifdef CONFIG_FIQ
  52         show_fiq_list(p, prec);
  53 #endif
  54 #ifdef CONFIG_SMP
  55         show_ipi_list(p, prec);
  56 #endif
  57         seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
  58         return 0;
  59 }
  60
  61 /*
  62  * handle_IRQ handles all hardware IRQ's.  Decoded IRQs should
  63  * not come via this function.  Instead, they should provide their
  64  * own 'handler'.  Used by platform code implementing C-based 1st
  65  * level decoding.
  66  */
  67 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
  68 {
  69         __handle_domain_irq(NULL, irq, false, regs);
  70 }
  71
  72 /*
  73  * asm_do_IRQ is the interface to be used from assembly code.
  74  */
  75 asmlinkage void __exception_irq_entry
  76 asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
  77 {
  78         handle_IRQ(irq, regs);
  79 }
  80
  81 void set_irq_flags(unsigned int irq, unsigned int iflags)
  82 {
  83         unsigned long clr = 0, set = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
  84
  85         if (irq >= nr_irqs) {
  86                 pr_err("Trying to set irq flags for IRQ%d\n", irq);
  87                 return;
  88         }
  89
  90         if (iflags & IRQF_VALID)
  91                 clr |= IRQ_NOREQUEST;
  92         if (iflags & IRQF_PROBE)
  93                 clr |= IRQ_NOPROBE;
  94         if (!(iflags & IRQF_NOAUTOEN))
  95                 clr |= IRQ_NOAUTOEN;
  96         /* Order is clear bits in "clr" then set bits in "set" */
  97         irq_modify_status(irq, clr, set & ~clr);
  98 }
  99 EXPORT_SYMBOL_GPL(set_irq_flags);
 100
 101 void __init init_IRQ(void)
 102 {
 103         int ret;
 104
 105         if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
 106                 irqchip_init();
 107         else
 108                 machine_desc->init_irq();
 109
 110         if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
 111             (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
 112                 if (!outer_cache.write_sec)
 113                         outer_cache.write_sec = machine_desc->l2c_write_sec;
 114                 ret = l2x0_of_init(machine_desc->l2c_aux_val,
 115                                    machine_desc->l2c_aux_mask);
 116                 if (ret)
 117                         pr_err("L2C: failed to init: %d\n", ret);
 118         }
 119 }
 120
 121 #ifdef CONFIG_MULTI_IRQ_HANDLER
 122 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
 123 {
 124         if (handle_arch_irq)
 125                 return;
 126
 127         handle_arch_irq = handle_irq;
 128 }
 129 #endif
 130
 131 #ifdef CONFIG_SPARSE_IRQ
 132 int __init arch_probe_nr_irqs(void)
 133 {
 134         nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
 135         return nr_irqs;
 136 }
 137 #endif
 138
 139 #ifdef CONFIG_HOTPLUG_CPU
 140 static bool migrate_one_irq(struct irq_desc *desc)
 141 {
 142         struct irq_data *d = irq_desc_get_irq_data(desc);
 143         const struct cpumask *affinity = irq_data_get_affinity_mask(d);
 144         struct irq_chip *c;
 145         bool ret = false;
 146
 147         /*
 148          * If this is a per-CPU interrupt, or the affinity does not
 149          * include this CPU, then we have nothing to do.
 150          */
 151         if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
 152                 return false;
 153
 154         if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
 155                 affinity = cpu_online_mask;
 156                 ret = true;
 157         }
 158
 159         c = irq_data_get_irq_chip(d);
 160         if (!c->irq_set_affinity)
 161                 pr_debug("IRQ%u: unable to set affinity\n", d->irq);
 162         else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
 163                 cpumask_copy(irq_data_get_affinity_mask(d), affinity);
 164
 165         return ret;
 166 }
 167
 168 /*
 169  * The current CPU has been marked offline.  Migrate IRQs off this CPU.
 170  * If the affinity settings do not allow other CPUs, force them onto any
 171  * available CPU.
 172  *
 173  * Note: we must iterate over all IRQs, whether they have an attached
 174  * action structure or not, as we need to get chained interrupts too.
 175  */
 176 void migrate_irqs(void)
 177 {
 178         unsigned int i;
 179         struct irq_desc *desc;
 180         unsigned long flags;
 181
 182         local_irq_save(flags);
 183
 184         for_each_irq_desc(i, desc) {
 185                 bool affinity_broken;
 186
 187                 raw_spin_lock(&desc->lock);
 188                 affinity_broken = migrate_one_irq(desc);
 189                 raw_spin_unlock(&desc->lock);
 190
 191                 if (affinity_broken)
 192                         pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
 193                                 i, smp_processor_id());
 194         }
 195
 196         local_irq_restore(flags);
 197 }
 198 #endif /* CONFIG_HOTPLUG_CPU */