arch/x86/kernel/irq.c

   1 /*
   2  * Common interrupt code for 32 and 64 bit
   3  */
   4 #include <linux/cpu.h>
   5 #include <linux/interrupt.h>
   6 #include <linux/kernel_stat.h>
   7 #include <linux/of.h>
   8 #include <linux/seq_file.h>
   9 #include <linux/smp.h>
  10 #include <linux/ftrace.h>
  11 #include <linux/delay.h>
  12
  13 #include <asm/apic.h>
  14 #include <asm/io_apic.h>
  15 #include <asm/irq.h>
  16 #include <asm/idle.h>
  17 #include <asm/mce.h>
  18 #include <asm/hw_irq.h>
  19
  20 atomic_t irq_err_count;
  21
  22 /* Function pointer for generic interrupt vector handling */
  23 void (*x86_platform_ipi_callback)(void) = NULL;
  24
  25 /*
  26  * 'what should we do if we get a hw irq event on an illegal vector'.
  27  * each architecture has to answer this themselves.
  28  */
  29 void ack_bad_irq(unsigned int irq)
  30 {
  31         if (printk_ratelimit())
  32                 pr_err("unexpected IRQ trap at vector %02x\n", irq);
  33
  34         /*
  35          * Currently unexpected vectors happen only on SMP and APIC.
  36          * We _must_ ack these because every local APIC has only N
  37          * irq slots per priority level, and a 'hanging, unacked' IRQ
  38          * holds up an irq slot - in excessive cases (when multiple
  39          * unexpected vectors occur) that might lock up the APIC
  40          * completely.
  41          * But only ack when the APIC is enabled -AK
  42          */
  43         ack_APIC_irq();
  44 }
  45
  46 #define irq_stats(x)            (&per_cpu(irq_stat, x))
  47 /*
  48  * /proc/interrupts printing for arch specific interrupts
  49  */
  50 int arch_show_interrupts(struct seq_file *p, int prec)
  51 {
  52         int j;
  53
  54         seq_printf(p, "%*s: ", prec, "NMI");
  55         for_each_online_cpu(j)
  56                 seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
  57         seq_printf(p, "  Non-maskable interrupts\n");
  58 #ifdef CONFIG_X86_LOCAL_APIC
  59         seq_printf(p, "%*s: ", prec, "LOC");
  60         for_each_online_cpu(j)
  61                 seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
  62         seq_printf(p, "  Local timer interrupts\n");
  63
  64         seq_printf(p, "%*s: ", prec, "SPU");
  65         for_each_online_cpu(j)
  66                 seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
  67         seq_printf(p, "  Spurious interrupts\n");
  68         seq_printf(p, "%*s: ", prec, "PMI");
  69         for_each_online_cpu(j)
  70                 seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
  71         seq_printf(p, "  Performance monitoring interrupts\n");
  72         seq_printf(p, "%*s: ", prec, "IWI");
  73         for_each_online_cpu(j)
  74                 seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
  75         seq_printf(p, "  IRQ work interrupts\n");
  76 #endif
  77         if (x86_platform_ipi_callback) {
  78                 seq_printf(p, "%*s: ", prec, "PLT");
  79                 for_each_online_cpu(j)
  80                         seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
  81                 seq_printf(p, "  Platform interrupts\n");
  82         }
  83 #ifdef CONFIG_SMP
  84         seq_printf(p, "%*s: ", prec, "RES");
  85         for_each_online_cpu(j)
  86                 seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
  87         seq_printf(p, "  Rescheduling interrupts\n");
  88         seq_printf(p, "%*s: ", prec, "CAL");
  89         for_each_online_cpu(j)
  90                 seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
  91         seq_printf(p, "  Function call interrupts\n");
  92         seq_printf(p, "%*s: ", prec, "TLB");
  93         for_each_online_cpu(j)
  94                 seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
  95         seq_printf(p, "  TLB shootdowns\n");
  96 #endif
  97 #ifdef CONFIG_X86_THERMAL_VECTOR
  98         seq_printf(p, "%*s: ", prec, "TRM");
  99         for_each_online_cpu(j)
 100                 seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
 101         seq_printf(p, "  Thermal event interrupts\n");
 102 #endif
 103 #ifdef CONFIG_X86_MCE_THRESHOLD
 104         seq_printf(p, "%*s: ", prec, "THR");
 105         for_each_online_cpu(j)
 106                 seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
 107         seq_printf(p, "  Threshold APIC interrupts\n");
 108 #endif
 109 #ifdef CONFIG_X86_MCE
 110         seq_printf(p, "%*s: ", prec, "MCE");
 111         for_each_online_cpu(j)
 112                 seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
 113         seq_printf(p, "  Machine check exceptions\n");
 114         seq_printf(p, "%*s: ", prec, "MCP");
 115         for_each_online_cpu(j)
 116                 seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
 117         seq_printf(p, "  Machine check polls\n");
 118 #endif
 119         seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
 120 #if defined(CONFIG_X86_IO_APIC)
 121         seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
 122 #endif
 123         return 0;
 124 }
 125
 126 /*
 127  * /proc/stat helpers
 128  */
 129 u64 arch_irq_stat_cpu(unsigned int cpu)
 130 {
 131         u64 sum = irq_stats(cpu)->__nmi_count;
 132
 133 #ifdef CONFIG_X86_LOCAL_APIC
 134         sum += irq_stats(cpu)->apic_timer_irqs;
 135         sum += irq_stats(cpu)->irq_spurious_count;
 136         sum += irq_stats(cpu)->apic_perf_irqs;
 137         sum += irq_stats(cpu)->apic_irq_work_irqs;
 138 #endif
 139         if (x86_platform_ipi_callback)
 140                 sum += irq_stats(cpu)->x86_platform_ipis;
 141 #ifdef CONFIG_SMP
 142         sum += irq_stats(cpu)->irq_resched_count;
 143         sum += irq_stats(cpu)->irq_call_count;
 144         sum += irq_stats(cpu)->irq_tlb_count;
 145 #endif
 146 #ifdef CONFIG_X86_THERMAL_VECTOR
 147         sum += irq_stats(cpu)->irq_thermal_count;
 148 #endif
 149 #ifdef CONFIG_X86_MCE_THRESHOLD
 150         sum += irq_stats(cpu)->irq_threshold_count;
 151 #endif
 152 #ifdef CONFIG_X86_MCE
 153         sum += per_cpu(mce_exception_count, cpu);
 154         sum += per_cpu(mce_poll_count, cpu);
 155 #endif
 156         return sum;
 157 }
 158
 159 u64 arch_irq_stat(void)
 160 {
 161         u64 sum = atomic_read(&irq_err_count);
 162
 163 #ifdef CONFIG_X86_IO_APIC
 164         sum += atomic_read(&irq_mis_count);
 165 #endif
 166         return sum;
 167 }
 168
 169
 170 /*
 171  * do_IRQ handles all normal device IRQ's (the special
 172  * SMP cross-CPU interrupts have their own specific
 173  * handlers).
 174  */
 175 unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 176 {
 177         struct pt_regs *old_regs = set_irq_regs(regs);
 178
 179         /* high bit used in ret_from_ code  */
 180         unsigned vector = ~regs->orig_ax;
 181         unsigned irq;
 182
 183         exit_idle();
 184         irq_enter();
 185
 186         irq = __this_cpu_read(vector_irq[vector]);
 187
 188         if (!handle_irq(irq, regs)) {
 189                 ack_APIC_irq();
 190
 191                 if (printk_ratelimit())
 192                         pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n",
 193                                 __func__, smp_processor_id(), vector, irq);
 194         }
 195
 196         irq_exit();
 197
 198         set_irq_regs(old_regs);
 199         return 1;
 200 }
 201
 202 /*
 203  * Handler for X86_PLATFORM_IPI_VECTOR.
 204  */
 205 void smp_x86_platform_ipi(struct pt_regs *regs)
 206 {
 207         struct pt_regs *old_regs = set_irq_regs(regs);
 208
 209         ack_APIC_irq();
 210
 211         exit_idle();
 212
 213         irq_enter();
 214
 215         inc_irq_stat(x86_platform_ipis);
 216
 217         if (x86_platform_ipi_callback)
 218                 x86_platform_ipi_callback();
 219
 220         irq_exit();
 221
 222         set_irq_regs(old_regs);
 223 }
 224
 225 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
 226
 227 #ifdef CONFIG_HOTPLUG_CPU
 228 /* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
 229 void fixup_irqs(void)
 230 {
 231         unsigned int irq, vector;
 232         static int warned;
 233         struct irq_desc *desc;
 234         struct irq_data *data;
 235         struct irq_chip *chip;
 236
 237         for_each_irq_desc(irq, desc) {
 238                 int break_affinity = 0;
 239                 int set_affinity = 1;
 240                 const struct cpumask *affinity;
 241
 242                 if (!desc)
 243                         continue;
 244                 if (irq == 2)
 245                         continue;
 246
 247                 /* interrupt's are disabled at this point */
 248                 raw_spin_lock(&desc->lock);
 249
 250                 data = irq_desc_get_irq_data(desc);
 251                 affinity = data->affinity;
 252                 if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
 253                     cpumask_subset(affinity, cpu_online_mask)) {
 254                         raw_spin_unlock(&desc->lock);
 255                         continue;
 256                 }
 257
 258                 /*
 259                  * Complete the irq move. This cpu is going down and for
 260                  * non intr-remapping case, we can't wait till this interrupt
 261                  * arrives at this cpu before completing the irq move.
 262                  */
 263                 irq_force_complete_move(irq);
 264
 265                 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
 266                         break_affinity = 1;
 267                         affinity = cpu_all_mask;
 268                 }
 269
 270                 chip = irq_data_get_irq_chip(data);
 271                 if (!irqd_can_move_in_process_context(data) && chip->irq_mask)
 272                         chip->irq_mask(data);
 273
 274                 if (chip->irq_set_affinity)
 275                         chip->irq_set_affinity(data, affinity, true);
 276                 else if (!(warned++))
 277                         set_affinity = 0;
 278
 279                 if (!irqd_can_move_in_process_context(data) &&
 280                     !irqd_irq_disabled(data) && chip->irq_unmask)
 281                         chip->irq_unmask(data);
 282
 283                 raw_spin_unlock(&desc->lock);
 284
 285                 if (break_affinity && set_affinity)
 286                         printk("Broke affinity for irq %i\n", irq);
 287                 else if (!set_affinity)
 288                         printk("Cannot set affinity for irq %i\n", irq);
 289         }
 290
 291         /*
 292          * We can remove mdelay() and then send spuriuous interrupts to
 293          * new cpu targets for all the irqs that were handled previously by
 294          * this cpu. While it works, I have seen spurious interrupt messages
 295          * (nothing wrong but still...).
 296          *
 297          * So for now, retain mdelay(1) and check the IRR and then send those
 298          * interrupts to new targets as this cpu is already offlined...
 299          */
 300         mdelay(1);
 301
 302         for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
 303                 unsigned int irr;
 304
 305                 if (__this_cpu_read(vector_irq[vector]) < 0)
 306                         continue;
 307
 308                 irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
 309                 if (irr  & (1 << (vector % 32))) {
 310                         irq = __this_cpu_read(vector_irq[vector]);
 311
 312                         desc = irq_to_desc(irq);
 313                         data = irq_desc_get_irq_data(desc);
 314                         chip = irq_data_get_irq_chip(data);
 315                         raw_spin_lock(&desc->lock);
 316                         if (chip->irq_retrigger)
 317                                 chip->irq_retrigger(data);
 318                         raw_spin_unlock(&desc->lock);
 319                 }
 320         }
 321 }
 322 #endif