1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Common interrupt code for 32 and 64 bit
4 */
5#include <linux/cpu.h>
6#include <linux/interrupt.h>
7#include <linux/kernel_stat.h>
8#include <linux/of.h>
9#include <linux/seq_file.h>
10#include <linux/smp.h>
11#include <linux/ftrace.h>
12#include <linux/delay.h>
13#include <linux/export.h>
14#include <linux/irq.h>
15
16#include <asm/irq_stack.h>
17#include <asm/apic.h>
18#include <asm/io_apic.h>
19#include <asm/irq.h>
20#include <asm/mce.h>
21#include <asm/hw_irq.h>
22#include <asm/desc.h>
23#include <asm/traps.h>
24#include <asm/thermal.h>
25
26#define CREATE_TRACE_POINTS
27#include <asm/trace/irq_vectors.h>
28
29DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
30EXPORT_PER_CPU_SYMBOL(irq_stat);
31
32atomic_t irq_err_count;
33
34/*
35 * 'what should we do if we get a hw irq event on an illegal vector'.
36 * each architecture has to answer this themselves.
37 */
38void ack_bad_irq(unsigned int irq)
39{
40 if (printk_ratelimit())
41 pr_err("unexpected IRQ trap at vector %02x\n", irq);
42
43 /*
44 * Currently unexpected vectors happen only on SMP and APIC.
45 * We _must_ ack these because every local APIC has only N
46 * irq slots per priority level, and a 'hanging, unacked' IRQ
47 * holds up an irq slot - in excessive cases (when multiple
48 * unexpected vectors occur) that might lock up the APIC
49 * completely.
50 * But only ack when the APIC is enabled -AK
51 */
52 apic_eoi();
53}
54
55#define irq_stats(x) (&per_cpu(irq_stat, x))
56/*
57 * /proc/interrupts printing for arch specific interrupts
58 */
59int arch_show_interrupts(struct seq_file *p, int prec)
60{
61 int j;
62
63 seq_printf(m: p, fmt: "%*s: ", prec, "NMI");
64 for_each_online_cpu(j)
65 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->__nmi_count);
66 seq_puts(m: p, s: " Non-maskable interrupts\n");
67#ifdef CONFIG_X86_LOCAL_APIC
68 seq_printf(m: p, fmt: "%*s: ", prec, "LOC");
69 for_each_online_cpu(j)
70 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->apic_timer_irqs);
71 seq_puts(m: p, s: " Local timer interrupts\n");
72
73 seq_printf(m: p, fmt: "%*s: ", prec, "SPU");
74 for_each_online_cpu(j)
75 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->irq_spurious_count);
76 seq_puts(m: p, s: " Spurious interrupts\n");
77 seq_printf(m: p, fmt: "%*s: ", prec, "PMI");
78 for_each_online_cpu(j)
79 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->apic_perf_irqs);
80 seq_puts(m: p, s: " Performance monitoring interrupts\n");
81 seq_printf(m: p, fmt: "%*s: ", prec, "IWI");
82 for_each_online_cpu(j)
83 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->apic_irq_work_irqs);
84 seq_puts(m: p, s: " IRQ work interrupts\n");
85 seq_printf(m: p, fmt: "%*s: ", prec, "RTR");
86 for_each_online_cpu(j)
87 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->icr_read_retry_count);
88 seq_puts(m: p, s: " APIC ICR read retries\n");
89 if (x86_platform_ipi_callback) {
90 seq_printf(m: p, fmt: "%*s: ", prec, "PLT");
91 for_each_online_cpu(j)
92 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->x86_platform_ipis);
93 seq_puts(m: p, s: " Platform interrupts\n");
94 }
95#endif
96#ifdef CONFIG_SMP
97 seq_printf(m: p, fmt: "%*s: ", prec, "RES");
98 for_each_online_cpu(j)
99 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->irq_resched_count);
100 seq_puts(m: p, s: " Rescheduling interrupts\n");
101 seq_printf(m: p, fmt: "%*s: ", prec, "CAL");
102 for_each_online_cpu(j)
103 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->irq_call_count);
104 seq_puts(m: p, s: " Function call interrupts\n");
105 seq_printf(m: p, fmt: "%*s: ", prec, "TLB");
106 for_each_online_cpu(j)
107 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->irq_tlb_count);
108 seq_puts(m: p, s: " TLB shootdowns\n");
109#endif
110#ifdef CONFIG_X86_THERMAL_VECTOR
111 seq_printf(m: p, fmt: "%*s: ", prec, "TRM");
112 for_each_online_cpu(j)
113 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->irq_thermal_count);
114 seq_puts(m: p, s: " Thermal event interrupts\n");
115#endif
116#ifdef CONFIG_X86_MCE_THRESHOLD
117 seq_printf(m: p, fmt: "%*s: ", prec, "THR");
118 for_each_online_cpu(j)
119 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->irq_threshold_count);
120 seq_puts(m: p, s: " Threshold APIC interrupts\n");
121#endif
122#ifdef CONFIG_X86_MCE_AMD
123 seq_printf(m: p, fmt: "%*s: ", prec, "DFR");
124 for_each_online_cpu(j)
125 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->irq_deferred_error_count);
126 seq_puts(m: p, s: " Deferred Error APIC interrupts\n");
127#endif
128#ifdef CONFIG_X86_MCE
129 seq_printf(m: p, fmt: "%*s: ", prec, "MCE");
130 for_each_online_cpu(j)
131 seq_printf(m: p, fmt: "%10u ", per_cpu(mce_exception_count, j));
132 seq_puts(m: p, s: " Machine check exceptions\n");
133 seq_printf(m: p, fmt: "%*s: ", prec, "MCP");
134 for_each_online_cpu(j)
135 seq_printf(m: p, fmt: "%10u ", per_cpu(mce_poll_count, j));
136 seq_puts(m: p, s: " Machine check polls\n");
137#endif
138#ifdef CONFIG_X86_HV_CALLBACK_VECTOR
139 if (test_bit(HYPERVISOR_CALLBACK_VECTOR, system_vectors)) {
140 seq_printf(m: p, fmt: "%*s: ", prec, "HYP");
141 for_each_online_cpu(j)
142 seq_printf(m: p, fmt: "%10u ",
143 irq_stats(j)->irq_hv_callback_count);
144 seq_puts(m: p, s: " Hypervisor callback interrupts\n");
145 }
146#endif
147#if IS_ENABLED(CONFIG_HYPERV)
148 if (test_bit(HYPERV_REENLIGHTENMENT_VECTOR, system_vectors)) {
149 seq_printf(m: p, fmt: "%*s: ", prec, "HRE");
150 for_each_online_cpu(j)
151 seq_printf(m: p, fmt: "%10u ",
152 irq_stats(j)->irq_hv_reenlightenment_count);
153 seq_puts(m: p, s: " Hyper-V reenlightenment interrupts\n");
154 }
155 if (test_bit(HYPERV_STIMER0_VECTOR, system_vectors)) {
156 seq_printf(m: p, fmt: "%*s: ", prec, "HVS");
157 for_each_online_cpu(j)
158 seq_printf(m: p, fmt: "%10u ",
159 irq_stats(j)->hyperv_stimer0_count);
160 seq_puts(m: p, s: " Hyper-V stimer0 interrupts\n");
161 }
162#endif
163 seq_printf(m: p, fmt: "%*s: %10u\n", prec, "ERR", atomic_read(v: &irq_err_count));
164#if defined(CONFIG_X86_IO_APIC)
165 seq_printf(m: p, fmt: "%*s: %10u\n", prec, "MIS", atomic_read(v: &irq_mis_count));
166#endif
167#ifdef CONFIG_HAVE_KVM
168 seq_printf(m: p, fmt: "%*s: ", prec, "PIN");
169 for_each_online_cpu(j)
170 seq_printf(m: p, fmt: "%10u ", irq_stats(j)->kvm_posted_intr_ipis);
171 seq_puts(m: p, s: " Posted-interrupt notification event\n");
172
173 seq_printf(m: p, fmt: "%*s: ", prec, "NPI");
174 for_each_online_cpu(j)
175 seq_printf(m: p, fmt: "%10u ",
176 irq_stats(j)->kvm_posted_intr_nested_ipis);
177 seq_puts(m: p, s: " Nested posted-interrupt event\n");
178
179 seq_printf(m: p, fmt: "%*s: ", prec, "PIW");
180 for_each_online_cpu(j)
181 seq_printf(m: p, fmt: "%10u ",
182 irq_stats(j)->kvm_posted_intr_wakeup_ipis);
183 seq_puts(m: p, s: " Posted-interrupt wakeup event\n");
184#endif
185 return 0;
186}
187
188/*
189 * /proc/stat helpers
190 */
191u64 arch_irq_stat_cpu(unsigned int cpu)
192{
193 u64 sum = irq_stats(cpu)->__nmi_count;
194
195#ifdef CONFIG_X86_LOCAL_APIC
196 sum += irq_stats(cpu)->apic_timer_irqs;
197 sum += irq_stats(cpu)->irq_spurious_count;
198 sum += irq_stats(cpu)->apic_perf_irqs;
199 sum += irq_stats(cpu)->apic_irq_work_irqs;
200 sum += irq_stats(cpu)->icr_read_retry_count;
201 if (x86_platform_ipi_callback)
202 sum += irq_stats(cpu)->x86_platform_ipis;
203#endif
204#ifdef CONFIG_SMP
205 sum += irq_stats(cpu)->irq_resched_count;
206 sum += irq_stats(cpu)->irq_call_count;
207#endif
208#ifdef CONFIG_X86_THERMAL_VECTOR
209 sum += irq_stats(cpu)->irq_thermal_count;
210#endif
211#ifdef CONFIG_X86_MCE_THRESHOLD
212 sum += irq_stats(cpu)->irq_threshold_count;
213#endif
214#ifdef CONFIG_X86_HV_CALLBACK_VECTOR
215 sum += irq_stats(cpu)->irq_hv_callback_count;
216#endif
217#if IS_ENABLED(CONFIG_HYPERV)
218 sum += irq_stats(cpu)->irq_hv_reenlightenment_count;
219 sum += irq_stats(cpu)->hyperv_stimer0_count;
220#endif
221#ifdef CONFIG_X86_MCE
222 sum += per_cpu(mce_exception_count, cpu);
223 sum += per_cpu(mce_poll_count, cpu);
224#endif
225 return sum;
226}
227
228u64 arch_irq_stat(void)
229{
230 u64 sum = atomic_read(v: &irq_err_count);
231 return sum;
232}
233
234static __always_inline void handle_irq(struct irq_desc *desc,
235 struct pt_regs *regs)
236{
237 if (IS_ENABLED(CONFIG_X86_64))
238 generic_handle_irq_desc(desc);
239 else
240 __handle_irq(desc, regs);
241}
242
243/*
244 * common_interrupt() handles all normal device IRQ's (the special SMP
245 * cross-CPU interrupts have their own entry points).
246 */
247DEFINE_IDTENTRY_IRQ(common_interrupt)
248{
249 struct pt_regs *old_regs = set_irq_regs(regs);
250 struct irq_desc *desc;
251
252 /* entry code tells RCU that we're not quiescent. Check it. */
253 RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
254
255 desc = __this_cpu_read(vector_irq[vector]);
256 if (likely(!IS_ERR_OR_NULL(desc))) {
257 handle_irq(desc, regs);
258 } else {
259 apic_eoi();
260
261 if (desc == VECTOR_UNUSED) {
262 pr_emerg_ratelimited("%s: %d.%u No irq handler for vector\n",
263 __func__, smp_processor_id(),
264 vector);
265 } else {
266 __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
267 }
268 }
269
270 set_irq_regs(old_regs);
271}
272
273#ifdef CONFIG_X86_LOCAL_APIC
274/* Function pointer for generic interrupt vector handling */
275void (*x86_platform_ipi_callback)(void) = NULL;
276/*
277 * Handler for X86_PLATFORM_IPI_VECTOR.
278 */
279DEFINE_IDTENTRY_SYSVEC(sysvec_x86_platform_ipi)
280{
281 struct pt_regs *old_regs = set_irq_regs(regs);
282
283 apic_eoi();
284 trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
285 inc_irq_stat(x86_platform_ipis);
286 if (x86_platform_ipi_callback)
287 x86_platform_ipi_callback();
288 trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
289 set_irq_regs(old_regs);
290}
291#endif
292
293#ifdef CONFIG_HAVE_KVM
294static void dummy_handler(void) {}
295static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;
296
297void kvm_set_posted_intr_wakeup_handler(void (*handler)(void))
298{
299 if (handler)
300 kvm_posted_intr_wakeup_handler = handler;
301 else {
302 kvm_posted_intr_wakeup_handler = dummy_handler;
303 synchronize_rcu();
304 }
305}
306EXPORT_SYMBOL_GPL(kvm_set_posted_intr_wakeup_handler);
307
308/*
309 * Handler for POSTED_INTERRUPT_VECTOR.
310 */
311DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_ipi)
312{
313 apic_eoi();
314 inc_irq_stat(kvm_posted_intr_ipis);
315}
316
317/*
318 * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
319 */
320DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_posted_intr_wakeup_ipi)
321{
322 apic_eoi();
323 inc_irq_stat(kvm_posted_intr_wakeup_ipis);
324 kvm_posted_intr_wakeup_handler();
325}
326
327/*
328 * Handler for POSTED_INTERRUPT_NESTED_VECTOR.
329 */
330DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_nested_ipi)
331{
332 apic_eoi();
333 inc_irq_stat(kvm_posted_intr_nested_ipis);
334}
335#endif
336
337
338#ifdef CONFIG_HOTPLUG_CPU
339/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
340void fixup_irqs(void)
341{
342 unsigned int irr, vector;
343 struct irq_desc *desc;
344 struct irq_data *data;
345 struct irq_chip *chip;
346
347 irq_migrate_all_off_this_cpu();
348
349 /*
350 * We can remove mdelay() and then send spurious interrupts to
351 * new cpu targets for all the irqs that were handled previously by
352 * this cpu. While it works, I have seen spurious interrupt messages
353 * (nothing wrong but still...).
354 *
355 * So for now, retain mdelay(1) and check the IRR and then send those
356 * interrupts to new targets as this cpu is already offlined...
357 */
358 mdelay(1);
359
360 /*
361 * We can walk the vector array of this cpu without holding
362 * vector_lock because the cpu is already marked !online, so
363 * nothing else will touch it.
364 */
365 for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
366 if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector])))
367 continue;
368
369 irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
370 if (irr & (1 << (vector % 32))) {
371 desc = __this_cpu_read(vector_irq[vector]);
372
373 raw_spin_lock(&desc->lock);
374 data = irq_desc_get_irq_data(desc);
375 chip = irq_data_get_irq_chip(d: data);
376 if (chip->irq_retrigger) {
377 chip->irq_retrigger(data);
378 __this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
379 }
380 raw_spin_unlock(&desc->lock);
381 }
382 if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
383 __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
384 }
385}
386#endif
387
388#ifdef CONFIG_X86_THERMAL_VECTOR
389static void smp_thermal_vector(void)
390{
391 if (x86_thermal_enabled())
392 intel_thermal_interrupt();
393 else
394 pr_err("CPU%d: Unexpected LVT thermal interrupt!\n",
395 smp_processor_id());
396}
397
398DEFINE_IDTENTRY_SYSVEC(sysvec_thermal)
399{
400 trace_thermal_apic_entry(THERMAL_APIC_VECTOR);
401 inc_irq_stat(irq_thermal_count);
402 smp_thermal_vector();
403 trace_thermal_apic_exit(THERMAL_APIC_VECTOR);
404 apic_eoi();
405}
406#endif
407

source code of linux/arch/x86/kernel/irq.c