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 #include <linux/export.h>
  13
  14 #include <asm/apic.h>
  15 #include <asm/io_apic.h>
  16 #include <asm/irq.h>
  17 #include <asm/idle.h>
  18 #include <asm/mce.h>
  19 #include <asm/hw_irq.h>
  20
  21 atomic_t irq_err_count;
  22
  23 /* Function pointer for generic interrupt vector handling */
  24 void (*x86_platform_ipi_callback)(void) = NULL;
  25
  26 /*
  27  * 'what should we do if we get a hw irq event on an illegal vector'.
  28  * each architecture has to answer this themselves.
  29  */
  30 void ack_bad_irq(unsigned int irq)
  31 {
  32         if (printk_ratelimit())
  33                 pr_err("unexpected IRQ trap at vector %02x\n", irq);
  34
  35         /*
  36          * Currently unexpected vectors happen only on SMP and APIC.
  37          * We _must_ ack these because every local APIC has only N
  38          * irq slots per priority level, and a 'hanging, unacked' IRQ
  39          * holds up an irq slot - in excessive cases (when multiple
  40          * unexpected vectors occur) that might lock up the APIC
  41          * completely.
  42          * But only ack when the APIC is enabled -AK
  43          */
  44         ack_APIC_irq();
  45 }
  46
  47 #define irq_stats(x)            (&per_cpu(irq_stat, x))
  48 /*
  49  * /proc/interrupts printing for arch specific interrupts
  50  */
  51 int arch_show_interrupts(struct seq_file *p, int prec)
  52 {
  53         int j;
  54
  55         seq_printf(p, "%*s: ", prec, "NMI");
  56         for_each_online_cpu(j)
  57                 seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
  58         seq_printf(p, "  Non-maskable interrupts\n");
  59 #ifdef CONFIG_X86_LOCAL_APIC
  60         seq_printf(p, "%*s: ", prec, "LOC");
  61         for_each_online_cpu(j)
  62                 seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
  63         seq_printf(p, "  Local timer interrupts\n");
  64
  65         seq_printf(p, "%*s: ", prec, "SPU");
  66         for_each_online_cpu(j)
  67                 seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
  68         seq_printf(p, "  Spurious interrupts\n");
  69         seq_printf(p, "%*s: ", prec, "PMI");
  70         for_each_online_cpu(j)
  71                 seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
  72         seq_printf(p, "  Performance monitoring interrupts\n");
  73         seq_printf(p, "%*s: ", prec, "IWI");
  74         for_each_online_cpu(j)
  75                 seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
  76         seq_printf(p, "  IRQ work interrupts\n");
  77         seq_printf(p, "%*s: ", prec, "RTR");
  78         for_each_online_cpu(j)
  79                 seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
  80         seq_printf(p, "  APIC ICR read retries\n");
  81 #endif
  82         if (x86_platform_ipi_callback) {
  83                 seq_printf(p, "%*s: ", prec, "PLT");
  84                 for_each_online_cpu(j)
  85                         seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
  86                 seq_printf(p, "  Platform interrupts\n");
  87         }
  88 #ifdef CONFIG_SMP
  89         seq_printf(p, "%*s: ", prec, "RES");
  90         for_each_online_cpu(j)
  91                 seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
  92         seq_printf(p, "  Rescheduling interrupts\n");
  93         seq_printf(p, "%*s: ", prec, "CAL");
  94         for_each_online_cpu(j)
  95                 seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
  96                                         irq_stats(j)->irq_tlb_count);
  97         seq_printf(p, "  Function call interrupts\n");
  98         seq_printf(p, "%*s: ", prec, "TLB");
  99         for_each_online_cpu(j)
 100                 seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
 101         seq_printf(p, "  TLB shootdowns\n");
 102 #endif
 103 #ifdef CONFIG_X86_THERMAL_VECTOR
 104         seq_printf(p, "%*s: ", prec, "TRM");
 105         for_each_online_cpu(j)
 106                 seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
 107         seq_printf(p, "  Thermal event interrupts\n");
 108 #endif
 109 #ifdef CONFIG_X86_MCE_THRESHOLD
 110         seq_printf(p, "%*s: ", prec, "THR");
 111         for_each_online_cpu(j)
 112                 seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
 113         seq_printf(p, "  Threshold APIC interrupts\n");
 114 #endif
 115 #ifdef CONFIG_X86_MCE
 116         seq_printf(p, "%*s: ", prec, "MCE");
 117         for_each_online_cpu(j)
 118                 seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
 119         seq_printf(p, "  Machine check exceptions\n");
 120         seq_printf(p, "%*s: ", prec, "MCP");
 121         for_each_online_cpu(j)
 122                 seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
 123         seq_printf(p, "  Machine check polls\n");
 124 #endif
 125         seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
 126 #if defined(CONFIG_X86_IO_APIC)
 127         seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
 128 #endif
 129         return 0;
 130 }
 131
 132 /*
 133  * /proc/stat helpers
 134  */
 135 u64 arch_irq_stat_cpu(unsigned int cpu)
 136 {
 137         u64 sum = irq_stats(cpu)->__nmi_count;
 138
 139 #ifdef CONFIG_X86_LOCAL_APIC
 140         sum += irq_stats(cpu)->apic_timer_irqs;
 141         sum += irq_stats(cpu)->irq_spurious_count;
 142         sum += irq_stats(cpu)->apic_perf_irqs;
 143         sum += irq_stats(cpu)->apic_irq_work_irqs;
 144         sum += irq_stats(cpu)->icr_read_retry_count;
 145 #endif
 146         if (x86_platform_ipi_callback)
 147                 sum += irq_stats(cpu)->x86_platform_ipis;
 148 #ifdef CONFIG_SMP
 149         sum += irq_stats(cpu)->irq_resched_count;
 150         sum += irq_stats(cpu)->irq_call_count;
 151 #endif
 152 #ifdef CONFIG_X86_THERMAL_VECTOR
 153         sum += irq_stats(cpu)->irq_thermal_count;
 154 #endif
 155 #ifdef CONFIG_X86_MCE_THRESHOLD
 156         sum += irq_stats(cpu)->irq_threshold_count;
 157 #endif
 158 #ifdef CONFIG_X86_MCE
 159         sum += per_cpu(mce_exception_count, cpu);
 160         sum += per_cpu(mce_poll_count, cpu);
 161 #endif
 162         return sum;
 163 }
 164
 165 u64 arch_irq_stat(void)
 166 {
 167         u64 sum = atomic_read(&irq_err_count);
 168
 169 #ifdef CONFIG_X86_IO_APIC
 170         sum += atomic_read(&irq_mis_count);
 171 #endif
 172         return sum;
 173 }
 174
 175
 176 /*
 177  * do_IRQ handles all normal device IRQ's (the special
 178  * SMP cross-CPU interrupts have their own specific
 179  * handlers).
 180  */
 181 unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 182 {
 183         struct pt_regs *old_regs = set_irq_regs(regs);
 184
 185         /* high bit used in ret_from_ code  */
 186         unsigned vector = ~regs->orig_ax;
 187         unsigned irq;
 188
 189         irq_enter();
 190         exit_idle();
 191
 192         irq = __this_cpu_read(vector_irq[vector]);
 193
 194         if (!handle_irq(irq, regs)) {
 195                 ack_APIC_irq();
 196
 197                 if (printk_ratelimit())
 198                         pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n",
 199                                 __func__, smp_processor_id(), vector, irq);
 200         }
 201
 202         irq_exit();
 203
 204         set_irq_regs(old_regs);
 205         return 1;
 206 }
 207
 208 /*
 209  * Handler for X86_PLATFORM_IPI_VECTOR.
 210  */
 211 void smp_x86_platform_ipi(struct pt_regs *regs)
 212 {
 213         struct pt_regs *old_regs = set_irq_regs(regs);
 214
 215         ack_APIC_irq();
 216
 217         irq_enter();
 218
 219         exit_idle();
 220
 221         inc_irq_stat(x86_platform_ipis);
 222
 223         if (x86_platform_ipi_callback)
 224                 x86_platform_ipi_callback();
 225
 226         irq_exit();
 227
 228         set_irq_regs(old_regs);
 229 }
 230
 231 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
 232
 233 #ifdef CONFIG_HOTPLUG_CPU
 234 /* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
 235 void fixup_irqs(void)
 236 {
 237         unsigned int irq, vector;
 238         static int warned;
 239         struct irq_desc *desc;
 240         struct irq_data *data;
 241         struct irq_chip *chip;
 242
 243         for_each_irq_desc(irq, desc) {
 244                 int break_affinity = 0;
 245                 int set_affinity = 1;
 246                 const struct cpumask *affinity;
 247
 248                 if (!desc)
 249                         continue;
 250                 if (irq == 2)
 251                         continue;
 252
 253                 /* interrupt's are disabled at this point */
 254                 raw_spin_lock(&desc->lock);
 255
 256                 data = irq_desc_get_irq_data(desc);
 257                 affinity = data->affinity;
 258                 if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
 259                     cpumask_subset(affinity, cpu_online_mask)) {
 260                         raw_spin_unlock(&desc->lock);
 261                         continue;
 262                 }
 263
 264                 /*
 265                  * Complete the irq move. This cpu is going down and for
 266                  * non intr-remapping case, we can't wait till this interrupt
 267                  * arrives at this cpu before completing the irq move.
 268                  */
 269                 irq_force_complete_move(irq);
 270
 271                 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
 272                         break_affinity = 1;
 273                         affinity = cpu_online_mask;
 274                 }
 275
 276                 chip = irq_data_get_irq_chip(data);
 277                 if (!irqd_can_move_in_process_context(data) && chip->irq_mask)
 278                         chip->irq_mask(data);
 279
 280                 if (chip->irq_set_affinity)
 281                         chip->irq_set_affinity(data, affinity, true);
 282                 else if (!(warned++))
 283                         set_affinity = 0;
 284
 285                 /*
 286                  * We unmask if the irq was not marked masked by the
 287                  * core code. That respects the lazy irq disable
 288                  * behaviour.
 289                  */
 290                 if (!irqd_can_move_in_process_context(data) &&
 291                     !irqd_irq_masked(data) && chip->irq_unmask)
 292                         chip->irq_unmask(data);
 293
 294                 raw_spin_unlock(&desc->lock);
 295
 296                 if (break_affinity && set_affinity)
 297                         pr_notice("Broke affinity for irq %i\n", irq);
 298                 else if (!set_affinity)
 299                         pr_notice("Cannot set affinity for irq %i\n", irq);
 300         }
 301
 302         /*
 303          * We can remove mdelay() and then send spuriuous interrupts to
 304          * new cpu targets for all the irqs that were handled previously by
 305          * this cpu. While it works, I have seen spurious interrupt messages
 306          * (nothing wrong but still...).
 307          *
 308          * So for now, retain mdelay(1) and check the IRR and then send those
 309          * interrupts to new targets as this cpu is already offlined...
 310          */
 311         mdelay(1);
 312
 313         for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
 314                 unsigned int irr;
 315
 316                 if (__this_cpu_read(vector_irq[vector]) < 0)
 317                         continue;
 318
 319                 irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
 320                 if (irr  & (1 << (vector % 32))) {
 321                         irq = __this_cpu_read(vector_irq[vector]);
 322
 323                         desc = irq_to_desc(irq);
 324                         data = irq_desc_get_irq_data(desc);
 325                         chip = irq_data_get_irq_chip(data);
 326                         raw_spin_lock(&desc->lock);
 327                         if (chip->irq_retrigger)
 328                                 chip->irq_retrigger(data);
 329                         raw_spin_unlock(&desc->lock);
 330                 }
 331                 __this_cpu_write(vector_irq[vector], -1);
 332         }
 333 }
 334 #endif