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 #include <linux/irq.h>
  14
  15 #include <asm/apic.h>
  16 #include <asm/io_apic.h>
  17 #include <asm/irq.h>
  18 #include <asm/mce.h>
  19 #include <asm/hw_irq.h>
  20 #include <asm/desc.h>
  21
  22 #define CREATE_TRACE_POINTS
  23 #include <asm/trace/irq_vectors.h>
  24
  25 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
  26 EXPORT_PER_CPU_SYMBOL(irq_stat);
  27
  28 DEFINE_PER_CPU(struct pt_regs *, irq_regs);
  29 EXPORT_PER_CPU_SYMBOL(irq_regs);
  30
  31 atomic_t irq_err_count;
  32
  33 /*
  34  * 'what should we do if we get a hw irq event on an illegal vector'.
  35  * each architecture has to answer this themselves.
  36  */
  37 void ack_bad_irq(unsigned int irq)
  38 {
  39         if (printk_ratelimit())
  40                 pr_err("unexpected IRQ trap at vector %02x\n", irq);
  41
  42         /*
  43          * Currently unexpected vectors happen only on SMP and APIC.
  44          * We _must_ ack these because every local APIC has only N
  45          * irq slots per priority level, and a 'hanging, unacked' IRQ
  46          * holds up an irq slot - in excessive cases (when multiple
  47          * unexpected vectors occur) that might lock up the APIC
  48          * completely.
  49          * But only ack when the APIC is enabled -AK
  50          */
  51         ack_APIC_irq();
  52 }
  53
  54 #define irq_stats(x)            (&per_cpu(irq_stat, x))
  55 /*
  56  * /proc/interrupts printing for arch specific interrupts
  57  */
  58 int arch_show_interrupts(struct seq_file *p, int prec)
  59 {
  60         int j;
  61
  62         seq_printf(p, "%*s: ", prec, "NMI");
  63         for_each_online_cpu(j)
  64                 seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
  65         seq_puts(p, "  Non-maskable interrupts\n");
  66 #ifdef CONFIG_X86_LOCAL_APIC
  67         seq_printf(p, "%*s: ", prec, "LOC");
  68         for_each_online_cpu(j)
  69                 seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
  70         seq_puts(p, "  Local timer interrupts\n");
  71
  72         seq_printf(p, "%*s: ", prec, "SPU");
  73         for_each_online_cpu(j)
  74                 seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
  75         seq_puts(p, "  Spurious interrupts\n");
  76         seq_printf(p, "%*s: ", prec, "PMI");
  77         for_each_online_cpu(j)
  78                 seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
  79         seq_puts(p, "  Performance monitoring interrupts\n");
  80         seq_printf(p, "%*s: ", prec, "IWI");
  81         for_each_online_cpu(j)
  82                 seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
  83         seq_puts(p, "  IRQ work interrupts\n");
  84         seq_printf(p, "%*s: ", prec, "RTR");
  85         for_each_online_cpu(j)
  86                 seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
  87         seq_puts(p, "  APIC ICR read retries\n");
  88         if (x86_platform_ipi_callback) {
  89                 seq_printf(p, "%*s: ", prec, "PLT");
  90                 for_each_online_cpu(j)
  91                         seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
  92                 seq_puts(p, "  Platform interrupts\n");
  93         }
  94 #endif
  95 #ifdef CONFIG_SMP
  96         seq_printf(p, "%*s: ", prec, "RES");
  97         for_each_online_cpu(j)
  98                 seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
  99         seq_puts(p, "  Rescheduling interrupts\n");
 100         seq_printf(p, "%*s: ", prec, "CAL");
 101         for_each_online_cpu(j)
 102                 seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
 103         seq_puts(p, "  Function call interrupts\n");
 104         seq_printf(p, "%*s: ", prec, "TLB");
 105         for_each_online_cpu(j)
 106                 seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
 107         seq_puts(p, "  TLB shootdowns\n");
 108 #endif
 109 #ifdef CONFIG_X86_THERMAL_VECTOR
 110         seq_printf(p, "%*s: ", prec, "TRM");
 111         for_each_online_cpu(j)
 112                 seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
 113         seq_puts(p, "  Thermal event interrupts\n");
 114 #endif
 115 #ifdef CONFIG_X86_MCE_THRESHOLD
 116         seq_printf(p, "%*s: ", prec, "THR");
 117         for_each_online_cpu(j)
 118                 seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
 119         seq_puts(p, "  Threshold APIC interrupts\n");
 120 #endif
 121 #ifdef CONFIG_X86_MCE_AMD
 122         seq_printf(p, "%*s: ", prec, "DFR");
 123         for_each_online_cpu(j)
 124                 seq_printf(p, "%10u ", irq_stats(j)->irq_deferred_error_count);
 125         seq_puts(p, "  Deferred Error APIC interrupts\n");
 126 #endif
 127 #ifdef CONFIG_X86_MCE
 128         seq_printf(p, "%*s: ", prec, "MCE");
 129         for_each_online_cpu(j)
 130                 seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
 131         seq_puts(p, "  Machine check exceptions\n");
 132         seq_printf(p, "%*s: ", prec, "MCP");
 133         for_each_online_cpu(j)
 134                 seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
 135         seq_puts(p, "  Machine check polls\n");
 136 #endif
 137 #if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
 138         if (test_bit(HYPERVISOR_CALLBACK_VECTOR, system_vectors)) {
 139                 seq_printf(p, "%*s: ", prec, "HYP");
 140                 for_each_online_cpu(j)
 141                         seq_printf(p, "%10u ",
 142                                    irq_stats(j)->irq_hv_callback_count);
 143                 seq_puts(p, "  Hypervisor callback interrupts\n");
 144         }
 145 #endif
 146 #if IS_ENABLED(CONFIG_HYPERV)
 147         if (test_bit(HYPERV_REENLIGHTENMENT_VECTOR, system_vectors)) {
 148                 seq_printf(p, "%*s: ", prec, "HRE");
 149                 for_each_online_cpu(j)
 150                         seq_printf(p, "%10u ",
 151                                    irq_stats(j)->irq_hv_reenlightenment_count);
 152                 seq_puts(p, "  Hyper-V reenlightenment interrupts\n");
 153         }
 154         if (test_bit(HYPERV_STIMER0_VECTOR, system_vectors)) {
 155                 seq_printf(p, "%*s: ", prec, "HVS");
 156                 for_each_online_cpu(j)
 157                         seq_printf(p, "%10u ",
 158                                    irq_stats(j)->hyperv_stimer0_count);
 159                 seq_puts(p, "  Hyper-V stimer0 interrupts\n");
 160         }
 161 #endif
 162         seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
 163 #if defined(CONFIG_X86_IO_APIC)
 164         seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
 165 #endif
 166 #ifdef CONFIG_HAVE_KVM
 167         seq_printf(p, "%*s: ", prec, "PIN");
 168         for_each_online_cpu(j)
 169                 seq_printf(p, "%10u ", irq_stats(j)->kvm_posted_intr_ipis);
 170         seq_puts(p, "  Posted-interrupt notification event\n");
 171
 172         seq_printf(p, "%*s: ", prec, "NPI");
 173         for_each_online_cpu(j)
 174                 seq_printf(p, "%10u ",
 175                            irq_stats(j)->kvm_posted_intr_nested_ipis);
 176         seq_puts(p, "  Nested posted-interrupt event\n");
 177
 178         seq_printf(p, "%*s: ", prec, "PIW");
 179         for_each_online_cpu(j)
 180                 seq_printf(p, "%10u ",
 181                            irq_stats(j)->kvm_posted_intr_wakeup_ipis);
 182         seq_puts(p, "  Posted-interrupt wakeup event\n");
 183 #endif
 184         return 0;
 185 }
 186
 187 /*
 188  * /proc/stat helpers
 189  */
 190 u64 arch_irq_stat_cpu(unsigned int cpu)
 191 {
 192         u64 sum = irq_stats(cpu)->__nmi_count;
 193
 194 #ifdef CONFIG_X86_LOCAL_APIC
 195         sum += irq_stats(cpu)->apic_timer_irqs;
 196         sum += irq_stats(cpu)->irq_spurious_count;
 197         sum += irq_stats(cpu)->apic_perf_irqs;
 198         sum += irq_stats(cpu)->apic_irq_work_irqs;
 199         sum += irq_stats(cpu)->icr_read_retry_count;
 200         if (x86_platform_ipi_callback)
 201                 sum += irq_stats(cpu)->x86_platform_ipis;
 202 #endif
 203 #ifdef CONFIG_SMP
 204         sum += irq_stats(cpu)->irq_resched_count;
 205         sum += irq_stats(cpu)->irq_call_count;
 206 #endif
 207 #ifdef CONFIG_X86_THERMAL_VECTOR
 208         sum += irq_stats(cpu)->irq_thermal_count;
 209 #endif
 210 #ifdef CONFIG_X86_MCE_THRESHOLD
 211         sum += irq_stats(cpu)->irq_threshold_count;
 212 #endif
 213 #ifdef CONFIG_X86_MCE
 214         sum += per_cpu(mce_exception_count, cpu);
 215         sum += per_cpu(mce_poll_count, cpu);
 216 #endif
 217         return sum;
 218 }
 219
 220 u64 arch_irq_stat(void)
 221 {
 222         u64 sum = atomic_read(&irq_err_count);
 223         return sum;
 224 }
 225
 226
 227 /*
 228  * do_IRQ handles all normal device IRQ's (the special
 229  * SMP cross-CPU interrupts have their own specific
 230  * handlers).
 231  */
 232 __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 233 {
 234         struct pt_regs *old_regs = set_irq_regs(regs);
 235         struct irq_desc * desc;
 236         /* high bit used in ret_from_ code  */
 237         unsigned vector = ~regs->orig_ax;
 238
 239         entering_irq();
 240
 241         /* entering_irq() tells RCU that we're not quiescent.  Check it. */
 242         RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
 243
 244         desc = __this_cpu_read(vector_irq[vector]);
 245
 246         if (!handle_irq(desc, regs)) {
 247                 ack_APIC_irq();
 248
 249                 if (desc != VECTOR_RETRIGGERED) {
 250                         pr_emerg_ratelimited("%s: %d.%d No irq handler for vector\n",
 251                                              __func__, smp_processor_id(),
 252                                              vector);
 253                 } else {
 254                         __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
 255                 }
 256         }
 257
 258         exiting_irq();
 259
 260         set_irq_regs(old_regs);
 261         return 1;
 262 }
 263
 264 #ifdef CONFIG_X86_LOCAL_APIC
 265 /* Function pointer for generic interrupt vector handling */
 266 void (*x86_platform_ipi_callback)(void) = NULL;
 267 /*
 268  * Handler for X86_PLATFORM_IPI_VECTOR.
 269  */
 270 __visible void __irq_entry smp_x86_platform_ipi(struct pt_regs *regs)
 271 {
 272         struct pt_regs *old_regs = set_irq_regs(regs);
 273
 274         entering_ack_irq();
 275         trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
 276         inc_irq_stat(x86_platform_ipis);
 277         if (x86_platform_ipi_callback)
 278                 x86_platform_ipi_callback();
 279         trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
 280         exiting_irq();
 281         set_irq_regs(old_regs);
 282 }
 283 #endif
 284
 285 #ifdef CONFIG_HAVE_KVM
 286 static void dummy_handler(void) {}
 287 static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;
 288
 289 void kvm_set_posted_intr_wakeup_handler(void (*handler)(void))
 290 {
 291         if (handler)
 292                 kvm_posted_intr_wakeup_handler = handler;
 293         else
 294                 kvm_posted_intr_wakeup_handler = dummy_handler;
 295 }
 296 EXPORT_SYMBOL_GPL(kvm_set_posted_intr_wakeup_handler);
 297
 298 /*
 299  * Handler for POSTED_INTERRUPT_VECTOR.
 300  */
 301 __visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
 302 {
 303         struct pt_regs *old_regs = set_irq_regs(regs);
 304
 305         entering_ack_irq();
 306         inc_irq_stat(kvm_posted_intr_ipis);
 307         exiting_irq();
 308         set_irq_regs(old_regs);
 309 }
 310
 311 /*
 312  * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
 313  */
 314 __visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs)
 315 {
 316         struct pt_regs *old_regs = set_irq_regs(regs);
 317
 318         entering_ack_irq();
 319         inc_irq_stat(kvm_posted_intr_wakeup_ipis);
 320         kvm_posted_intr_wakeup_handler();
 321         exiting_irq();
 322         set_irq_regs(old_regs);
 323 }
 324
 325 /*
 326  * Handler for POSTED_INTERRUPT_NESTED_VECTOR.
 327  */
 328 __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs)
 329 {
 330         struct pt_regs *old_regs = set_irq_regs(regs);
 331
 332         entering_ack_irq();
 333         inc_irq_stat(kvm_posted_intr_nested_ipis);
 334         exiting_irq();
 335         set_irq_regs(old_regs);
 336 }
 337 #endif
 338
 339
 340 #ifdef CONFIG_HOTPLUG_CPU
 341 /* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
 342 void fixup_irqs(void)
 343 {
 344         unsigned int irr, vector;
 345         struct irq_desc *desc;
 346         struct irq_data *data;
 347         struct irq_chip *chip;
 348
 349         irq_migrate_all_off_this_cpu();
 350
 351         /*
 352          * We can remove mdelay() and then send spuriuous interrupts to
 353          * new cpu targets for all the irqs that were handled previously by
 354          * this cpu. While it works, I have seen spurious interrupt messages
 355          * (nothing wrong but still...).
 356          *
 357          * So for now, retain mdelay(1) and check the IRR and then send those
 358          * interrupts to new targets as this cpu is already offlined...
 359          */
 360         mdelay(1);
 361
 362         /*
 363          * We can walk the vector array of this cpu without holding
 364          * vector_lock because the cpu is already marked !online, so
 365          * nothing else will touch it.
 366          */
 367         for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
 368                 if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector])))
 369                         continue;
 370
 371                 irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
 372                 if (irr  & (1 << (vector % 32))) {
 373                         desc = __this_cpu_read(vector_irq[vector]);
 374
 375                         raw_spin_lock(&desc->lock);
 376                         data = irq_desc_get_irq_data(desc);
 377                         chip = irq_data_get_irq_chip(data);
 378                         if (chip->irq_retrigger) {
 379                                 chip->irq_retrigger(data);
 380                                 __this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
 381                         }
 382                         raw_spin_unlock(&desc->lock);
 383                 }
 384                 if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
 385                         __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
 386         }
 387 }
 388 #endif