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 <linux/uaccess.h>
  29 #include <asm/platform.h>
  30
  31 DECLARE_PER_CPU(unsigned long, nmi_count);
  32
  33 asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
  34 {
  35         int irq = irq_find_mapping(NULL, hwirq);
  36
  37 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  38         /* Debugging check for stack overflow: is there less than 1KB free? */
  39         {
  40                 unsigned long sp;
  41
  42                 __asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
  43                 sp &= THREAD_SIZE - 1;
  44
  45                 if (unlikely(sp < (sizeof(thread_info) + 1024)))
  46                         printk("Stack overflow in do_IRQ: %ld\n",
  47                                sp - sizeof(struct thread_info));
  48         }
  49 #endif
  50         generic_handle_irq(irq);
  51 }
  52
  53 int arch_show_interrupts(struct seq_file *p, int prec)
  54 {
  55         unsigned cpu __maybe_unused;
  56 #ifdef CONFIG_SMP
  57         show_ipi_list(p, prec);
  58 #endif
  59 #if XTENSA_FAKE_NMI
  60         seq_printf(p, "%*s:", prec, "NMI");
  61         for_each_online_cpu(cpu)
  62                 seq_printf(p, " %10lu", per_cpu(nmi_count, cpu));
  63         seq_puts(p, "   Non-maskable interrupts\n");
  64 #endif
  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 #ifdef XCHAL_INTTYPE_MASK_PROFILING
 110         } else if (mask & XCHAL_INTTYPE_MASK_PROFILING) {
 111                 irq_set_chip_and_handler_name(irq, irq_chip,
 112                                 handle_percpu_irq, "profiling");
 113                 irq_set_status_flags(irq, IRQ_LEVEL);
 114 #endif
 115         } else {/* XCHAL_INTTYPE_MASK_WRITE_ERROR */
 116                 /* XCHAL_INTTYPE_MASK_NMI */
 117                 irq_set_chip_and_handler_name(irq, irq_chip,
 118                                 handle_level_irq, "level");
 119                 irq_set_status_flags(irq, IRQ_LEVEL);
 120         }
 121         return 0;
 122 }
 123
 124 unsigned xtensa_map_ext_irq(unsigned ext_irq)
 125 {
 126         unsigned mask = XCHAL_INTTYPE_MASK_EXTERN_EDGE |
 127                 XCHAL_INTTYPE_MASK_EXTERN_LEVEL;
 128         unsigned i;
 129
 130         for (i = 0; mask; ++i, mask >>= 1) {
 131                 if ((mask & 1) && ext_irq-- == 0)
 132                         return i;
 133         }
 134         return XCHAL_NUM_INTERRUPTS;
 135 }
 136
 137 unsigned xtensa_get_ext_irq_no(unsigned irq)
 138 {
 139         unsigned mask = (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
 140                 XCHAL_INTTYPE_MASK_EXTERN_LEVEL) &
 141                 ((1u << irq) - 1);
 142         return hweight32(mask);
 143 }
 144
 145 void __init init_IRQ(void)
 146 {
 147 #ifdef CONFIG_OF
 148         irqchip_init();
 149 #else
 150 #ifdef CONFIG_HAVE_SMP
 151         xtensa_mx_init_legacy(NULL);
 152 #else
 153         xtensa_pic_init_legacy(NULL);
 154 #endif
 155 #endif
 156
 157 #ifdef CONFIG_SMP
 158         ipi_init();
 159 #endif
 160         variant_init_irq();
 161 }
 162
 163 #ifdef CONFIG_HOTPLUG_CPU
 164 /*
 165  * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
 166  * the affinity settings do not allow other CPUs, force them onto any
 167  * available CPU.
 168  */
 169 void migrate_irqs(void)
 170 {
 171         unsigned int i, cpu = smp_processor_id();
 172
 173         for_each_active_irq(i) {
 174                 struct irq_data *data = irq_get_irq_data(i);
 175                 struct cpumask *mask;
 176                 unsigned int newcpu;
 177
 178                 if (irqd_is_per_cpu(data))
 179                         continue;
 180
 181                 mask = irq_data_get_affinity_mask(data);
 182                 if (!cpumask_test_cpu(cpu, mask))
 183                         continue;
 184
 185                 newcpu = cpumask_any_and(mask, cpu_online_mask);
 186
 187                 if (newcpu >= nr_cpu_ids) {
 188                         pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n",
 189                                             i, cpu);
 190
 191                         cpumask_setall(mask);
 192                 }
 193                 irq_set_affinity(i, mask);
 194         }
 195 }
 196 #endif /* CONFIG_HOTPLUG_CPU */