arch/xtensa/kernel/irq.c

   1 /*
   2  * linux/arch/xtensa/kernel/irq.c
   3  *
   4  * Xtensa built-in interrupt controller and some generic functions copied
   5  * from i386.
   6  *
   7  * Copyright (C) 2002 - 2013 Tensilica, Inc.
   8  * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   9  *
  10  *
  11  * Chris Zankel <[email protected]>
  12  * Kevin Chea
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/irq.h>
  20 #include <linux/kernel_stat.h>
  21 #include <linux/irqchip.h>
  22 #include <linux/irqchip/xtensa-mx.h>
  23 #include <linux/irqchip/xtensa-pic.h>
  24 #include <linux/irqdomain.h>
  25 #include <linux/of.h>
  26
  27 #include <asm/mxregs.h>
  28 #include <asm/uaccess.h>
  29 #include <asm/platform.h>
  30
  31 atomic_t irq_err_count;
  32
  33 asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
  34 {
  35         int irq = irq_find_mapping(NULL, hwirq);
  36
  37         if (hwirq >= NR_IRQS) {
  38                 printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
  39                                 __func__, hwirq);
  40         }
  41
  42 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  43         /* Debugging check for stack overflow: is there less than 1KB free? */
  44         {
  45                 unsigned long sp;
  46
  47                 __asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
  48                 sp &= THREAD_SIZE - 1;
  49
  50                 if (unlikely(sp < (sizeof(thread_info) + 1024)))
  51                         printk("Stack overflow in do_IRQ: %ld\n",
  52                                sp - sizeof(struct thread_info));
  53         }
  54 #endif
  55         generic_handle_irq(irq);
  56 }
  57
  58 int arch_show_interrupts(struct seq_file *p, int prec)
  59 {
  60 #ifdef CONFIG_SMP
  61         show_ipi_list(p, prec);
  62 #endif
  63         seq_printf(p, "%*s: ", prec, "ERR");
  64         seq_printf(p, "%10u\n", atomic_read(&irq_err_count));
  65         return 0;
  66 }
  67
  68 int xtensa_irq_domain_xlate(const u32 *intspec, unsigned int intsize,
  69                 unsigned long int_irq, unsigned long ext_irq,
  70                 unsigned long *out_hwirq, unsigned int *out_type)
  71 {
  72         if (WARN_ON(intsize < 1 || intsize > 2))
  73                 return -EINVAL;
  74         if (intsize == 2 && intspec[1] == 1) {
  75                 int_irq = xtensa_map_ext_irq(ext_irq);
  76                 if (int_irq < XCHAL_NUM_INTERRUPTS)
  77                         *out_hwirq = int_irq;
  78                 else
  79                         return -EINVAL;
  80         } else {
  81                 *out_hwirq = int_irq;
  82         }
  83         *out_type = IRQ_TYPE_NONE;
  84         return 0;
  85 }
  86
  87 int xtensa_irq_map(struct irq_domain *d, unsigned int irq,
  88                 irq_hw_number_t hw)
  89 {
  90         struct irq_chip *irq_chip = d->host_data;
  91         u32 mask = 1 << hw;
  92
  93         if (mask & XCHAL_INTTYPE_MASK_SOFTWARE) {
  94                 irq_set_chip_and_handler_name(irq, irq_chip,
  95                                 handle_simple_irq, "level");
  96                 irq_set_status_flags(irq, IRQ_LEVEL);
  97         } else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE) {
  98                 irq_set_chip_and_handler_name(irq, irq_chip,
  99                                 handle_edge_irq, "edge");
 100                 irq_clear_status_flags(irq, IRQ_LEVEL);
 101         } else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL) {
 102                 irq_set_chip_and_handler_name(irq, irq_chip,
 103                                 handle_level_irq, "level");
 104                 irq_set_status_flags(irq, IRQ_LEVEL);
 105         } else if (mask & XCHAL_INTTYPE_MASK_TIMER) {
 106                 irq_set_chip_and_handler_name(irq, irq_chip,
 107                                 handle_percpu_irq, "timer");
 108                 irq_clear_status_flags(irq, IRQ_LEVEL);
 109         } else {/* XCHAL_INTTYPE_MASK_WRITE_ERROR */
 110                 /* XCHAL_INTTYPE_MASK_NMI */
 111                 irq_set_chip_and_handler_name(irq, irq_chip,
 112                                 handle_level_irq, "level");
 113                 irq_set_status_flags(irq, IRQ_LEVEL);
 114         }
 115         return 0;
 116 }
 117
 118 unsigned xtensa_map_ext_irq(unsigned ext_irq)
 119 {
 120         unsigned mask = XCHAL_INTTYPE_MASK_EXTERN_EDGE |
 121                 XCHAL_INTTYPE_MASK_EXTERN_LEVEL;
 122         unsigned i;
 123
 124         for (i = 0; mask; ++i, mask >>= 1) {
 125                 if ((mask & 1) && ext_irq-- == 0)
 126                         return i;
 127         }
 128         return XCHAL_NUM_INTERRUPTS;
 129 }
 130
 131 unsigned xtensa_get_ext_irq_no(unsigned irq)
 132 {
 133         unsigned mask = (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
 134                 XCHAL_INTTYPE_MASK_EXTERN_LEVEL) &
 135                 ((1u << irq) - 1);
 136         return hweight32(mask);
 137 }
 138
 139 void __init init_IRQ(void)
 140 {
 141 #ifdef CONFIG_OF
 142         irqchip_init();
 143 #else
 144 #ifdef CONFIG_HAVE_SMP
 145         xtensa_mx_init_legacy(NULL);
 146 #else
 147         xtensa_pic_init_legacy(NULL);
 148 #endif
 149 #endif
 150
 151 #ifdef CONFIG_SMP
 152         ipi_init();
 153 #endif
 154         variant_init_irq();
 155 }
 156
 157 #ifdef CONFIG_HOTPLUG_CPU
 158 static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu)
 159 {
 160         struct irq_desc *desc = irq_to_desc(irq);
 161         struct irq_chip *chip = irq_data_get_irq_chip(data);
 162         unsigned long flags;
 163
 164         raw_spin_lock_irqsave(&desc->lock, flags);
 165         if (chip->irq_set_affinity)
 166                 chip->irq_set_affinity(data, cpumask_of(cpu), false);
 167         raw_spin_unlock_irqrestore(&desc->lock, flags);
 168 }
 169
 170 /*
 171  * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
 172  * the affinity settings do not allow other CPUs, force them onto any
 173  * available CPU.
 174  */
 175 void migrate_irqs(void)
 176 {
 177         unsigned int i, cpu = smp_processor_id();
 178         struct irq_desc *desc;
 179
 180         for_each_irq_desc(i, desc) {
 181                 struct irq_data *data = irq_desc_get_irq_data(desc);
 182                 unsigned int newcpu;
 183
 184                 if (irqd_is_per_cpu(data))
 185                         continue;
 186
 187                 if (!cpumask_test_cpu(cpu, data->affinity))
 188                         continue;
 189
 190                 newcpu = cpumask_any_and(data->affinity, cpu_online_mask);
 191
 192                 if (newcpu >= nr_cpu_ids) {
 193                         pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n",
 194                                             i, cpu);
 195
 196                         cpumask_setall(data->affinity);
 197                         newcpu = cpumask_any_and(data->affinity,
 198                                                  cpu_online_mask);
 199                 }
 200
 201                 route_irq(data, i, newcpu);
 202         }
 203 }
 204 #endif /* CONFIG_HOTPLUG_CPU */