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/errno.h>
  35 #include <linux/list.h>
  36 #include <linux/kallsyms.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/export.h>
  39
  40 #include <asm/exception.h>
  41 #include <asm/mach/arch.h>
  42 #include <asm/mach/irq.h>
  43 #include <asm/mach/time.h>
  44
  45 #include <linux/mt_sched_mon.h>
  46 unsigned long irq_err_count;
  47
  48 int arch_show_interrupts(struct seq_file *p, int prec)
  49 {
  50 #ifdef CONFIG_FIQ
  51         show_fiq_list(p, prec);
  52 #endif
  53 #ifdef CONFIG_SMP
  54         show_ipi_list(p, prec);
  55 #endif
  56         seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
  57         return 0;
  58 }
  59
  60 #ifdef CONFIG_MTK_SCHED_TRACERS
  61 #include <trace/events/mtk_events.h>
  62 #endif
  63
  64 /*
  65  * handle_IRQ handles all hardware IRQ's.  Decoded IRQs should
  66  * not come via this function.  Instead, they should provide their
  67  * own 'handler'.  Used by platform code implementing C-based 1st
  68  * level decoding.
  69  */
  70 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
  71 {
  72         struct pt_regs *old_regs = set_irq_regs(regs);
  73 #ifdef CONFIG_MTK_SCHED_TRACERS
  74     struct irq_desc *desc;
  75 #endif
  76
  77         irq_enter();
  78     mt_trace_ISR_start(irq);
  79 #ifdef CONFIG_MTK_SCHED_TRACERS
  80     desc = irq_to_desc(irq);
  81     trace_irq_entry(irq,
  82             (desc && desc->action && desc->action->name) ? desc->action->name : "-");
  83 #endif
  84
  85         /*
  86          * Some hardware gives randomly wrong interrupts.  Rather
  87          * than crashing, do something sensible.
  88          */
  89         if (unlikely(irq >= nr_irqs)) {
  90                 if (printk_ratelimit())
  91                         printk(KERN_WARNING "Bad IRQ%u\n", irq);
  92                 ack_bad_irq(irq);
  93         } else {
  94                 generic_handle_irq(irq);
  95         }
  96 #ifdef CONFIG_MTK_SCHED_TRACERS
  97     trace_irq_exit(irq);
  98 #endif
  99     mt_trace_ISR_end(irq);
 100         irq_exit();
 101         set_irq_regs(old_regs);
 102 }
 103
 104 /*
 105  * asm_do_IRQ is the interface to be used from assembly code.
 106  */
 107 asmlinkage void __exception_irq_entry
 108 asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
 109 {
 110         handle_IRQ(irq, regs);
 111 }
 112
 113 void set_irq_flags(unsigned int irq, unsigned int iflags)
 114 {
 115         unsigned long clr = 0, set = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 116
 117         if (irq >= nr_irqs) {
 118                 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
 119                 return;
 120         }
 121
 122         if (iflags & IRQF_VALID)
 123                 clr |= IRQ_NOREQUEST;
 124         if (iflags & IRQF_PROBE)
 125                 clr |= IRQ_NOPROBE;
 126         if (!(iflags & IRQF_NOAUTOEN))
 127                 clr |= IRQ_NOAUTOEN;
 128         /* Order is clear bits in "clr" then set bits in "set" */
 129         irq_modify_status(irq, clr, set & ~clr);
 130 }
 131 EXPORT_SYMBOL_GPL(set_irq_flags);
 132
 133 void __init init_IRQ(void)
 134 {
 135         if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
 136                 irqchip_init();
 137         else
 138                 machine_desc->init_irq();
 139 }
 140
 141 #ifdef CONFIG_MULTI_IRQ_HANDLER
 142 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
 143 {
 144         if (handle_arch_irq)
 145                 return;
 146
 147         handle_arch_irq = handle_irq;
 148 }
 149 #endif
 150
 151 #ifdef CONFIG_SPARSE_IRQ
 152 int __init arch_probe_nr_irqs(void)
 153 {
 154         nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
 155         return nr_irqs;
 156 }
 157 #endif
 158
 159 #ifdef CONFIG_HOTPLUG_CPU
 160
 161 static bool migrate_one_irq(struct irq_desc *desc)
 162 {
 163         struct irq_data *d = irq_desc_get_irq_data(desc);
 164         const struct cpumask *affinity = d->affinity;
 165         struct irq_chip *c;
 166         bool ret = false;
 167
 168         /*
 169          * If this is a per-CPU interrupt, or the affinity does not
 170          * include this CPU, then we have nothing to do.
 171          */
 172         if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
 173                 return false;
 174
 175         if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
 176                 affinity = cpu_online_mask;
 177                 ret = true;
 178         }
 179
 180         c = irq_data_get_irq_chip(d);
 181         if (!c->irq_set_affinity)
 182                 pr_debug("IRQ%u: unable to set affinity\n", d->irq);
 183         else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret)
 184                 cpumask_copy(d->affinity, affinity);
 185
 186         return ret;
 187 }
 188
 189 /*
 190  * The current CPU has been marked offline.  Migrate IRQs off this CPU.
 191  * If the affinity settings do not allow other CPUs, force them onto any
 192  * available CPU.
 193  *
 194  * Note: we must iterate over all IRQs, whether they have an attached
 195  * action structure or not, as we need to get chained interrupts too.
 196  */
 197 void migrate_irqs(void)
 198 {
 199         unsigned int i;
 200         struct irq_desc *desc;
 201         unsigned long flags;
 202
 203         local_irq_save(flags);
 204
 205         for_each_irq_desc(i, desc) {
 206                 bool affinity_broken;
 207
 208                 raw_spin_lock(&desc->lock);
 209                 affinity_broken = migrate_one_irq(desc);
 210                 raw_spin_unlock(&desc->lock);
 211
 212                 if (affinity_broken && printk_ratelimit())
 213                         pr_warning("IRQ%u no longer affine to CPU%u\n", i,
 214                                 smp_processor_id());
 215         }
 216
 217         local_irq_restore(flags);
 218 }
 219 #endif /* CONFIG_HOTPLUG_CPU */