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/apic.h>
17 #include <asm/io_apic.h>
18 #include <asm/irq.h>
19 #include <asm/mce.h>
20 #include <asm/hw_irq.h>
21 #include <asm/desc.h>
22
23 #define CREATE_TRACE_POINTS
24 #include <asm/trace/irq_vectors.h>
25
26 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
27 EXPORT_PER_CPU_SYMBOL(irq_stat);
28
29 DEFINE_PER_CPU(struct pt_regs *, irq_regs);
30 EXPORT_PER_CPU_SYMBOL(irq_regs);
31
32 atomic_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 */
ack_bad_irq(unsigned int irq)38 void 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 ack_APIC_irq();
53 }
54
55 #define irq_stats(x) (&per_cpu(irq_stat, x))
56 /*
57 * /proc/interrupts printing for arch specific interrupts
58 */
arch_show_interrupts(struct seq_file * p,int prec)59 int arch_show_interrupts(struct seq_file *p, int prec)
60 {
61 int j;
62
63 seq_printf(p, "%*s: ", prec, "NMI");
64 for_each_online_cpu(j)
65 seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
66 seq_puts(p, " Non-maskable interrupts\n");
67 #ifdef CONFIG_X86_LOCAL_APIC
68 seq_printf(p, "%*s: ", prec, "LOC");
69 for_each_online_cpu(j)
70 seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
71 seq_puts(p, " Local timer interrupts\n");
72
73 seq_printf(p, "%*s: ", prec, "SPU");
74 for_each_online_cpu(j)
75 seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
76 seq_puts(p, " Spurious interrupts\n");
77 seq_printf(p, "%*s: ", prec, "PMI");
78 for_each_online_cpu(j)
79 seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
80 seq_puts(p, " Performance monitoring interrupts\n");
81 seq_printf(p, "%*s: ", prec, "IWI");
82 for_each_online_cpu(j)
83 seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
84 seq_puts(p, " IRQ work interrupts\n");
85 seq_printf(p, "%*s: ", prec, "RTR");
86 for_each_online_cpu(j)
87 seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
88 seq_puts(p, " APIC ICR read retries\n");
89 if (x86_platform_ipi_callback) {
90 seq_printf(p, "%*s: ", prec, "PLT");
91 for_each_online_cpu(j)
92 seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
93 seq_puts(p, " Platform interrupts\n");
94 }
95 #endif
96 #ifdef CONFIG_SMP
97 seq_printf(p, "%*s: ", prec, "RES");
98 for_each_online_cpu(j)
99 seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
100 seq_puts(p, " Rescheduling interrupts\n");
101 seq_printf(p, "%*s: ", prec, "CAL");
102 for_each_online_cpu(j)
103 seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
104 seq_puts(p, " Function call interrupts\n");
105 seq_printf(p, "%*s: ", prec, "TLB");
106 for_each_online_cpu(j)
107 seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
108 seq_puts(p, " TLB shootdowns\n");
109 #endif
110 #ifdef CONFIG_X86_THERMAL_VECTOR
111 seq_printf(p, "%*s: ", prec, "TRM");
112 for_each_online_cpu(j)
113 seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
114 seq_puts(p, " Thermal event interrupts\n");
115 #endif
116 #ifdef CONFIG_X86_MCE_THRESHOLD
117 seq_printf(p, "%*s: ", prec, "THR");
118 for_each_online_cpu(j)
119 seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
120 seq_puts(p, " Threshold APIC interrupts\n");
121 #endif
122 #ifdef CONFIG_X86_MCE_AMD
123 seq_printf(p, "%*s: ", prec, "DFR");
124 for_each_online_cpu(j)
125 seq_printf(p, "%10u ", irq_stats(j)->irq_deferred_error_count);
126 seq_puts(p, " Deferred Error APIC interrupts\n");
127 #endif
128 #ifdef CONFIG_X86_MCE
129 seq_printf(p, "%*s: ", prec, "MCE");
130 for_each_online_cpu(j)
131 seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
132 seq_puts(p, " Machine check exceptions\n");
133 seq_printf(p, "%*s: ", prec, "MCP");
134 for_each_online_cpu(j)
135 seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
136 seq_puts(p, " 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(p, "%*s: ", prec, "HYP");
141 for_each_online_cpu(j)
142 seq_printf(p, "%10u ",
143 irq_stats(j)->irq_hv_callback_count);
144 seq_puts(p, " 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(p, "%*s: ", prec, "HRE");
150 for_each_online_cpu(j)
151 seq_printf(p, "%10u ",
152 irq_stats(j)->irq_hv_reenlightenment_count);
153 seq_puts(p, " Hyper-V reenlightenment interrupts\n");
154 }
155 if (test_bit(HYPERV_STIMER0_VECTOR, system_vectors)) {
156 seq_printf(p, "%*s: ", prec, "HVS");
157 for_each_online_cpu(j)
158 seq_printf(p, "%10u ",
159 irq_stats(j)->hyperv_stimer0_count);
160 seq_puts(p, " Hyper-V stimer0 interrupts\n");
161 }
162 #endif
163 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
164 #if defined(CONFIG_X86_IO_APIC)
165 seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
166 #endif
167 #ifdef CONFIG_HAVE_KVM
168 seq_printf(p, "%*s: ", prec, "PIN");
169 for_each_online_cpu(j)
170 seq_printf(p, "%10u ", irq_stats(j)->kvm_posted_intr_ipis);
171 seq_puts(p, " Posted-interrupt notification event\n");
172
173 seq_printf(p, "%*s: ", prec, "NPI");
174 for_each_online_cpu(j)
175 seq_printf(p, "%10u ",
176 irq_stats(j)->kvm_posted_intr_nested_ipis);
177 seq_puts(p, " Nested posted-interrupt event\n");
178
179 seq_printf(p, "%*s: ", prec, "PIW");
180 for_each_online_cpu(j)
181 seq_printf(p, "%10u ",
182 irq_stats(j)->kvm_posted_intr_wakeup_ipis);
183 seq_puts(p, " Posted-interrupt wakeup event\n");
184 #endif
185 return 0;
186 }
187
188 /*
189 * /proc/stat helpers
190 */
arch_irq_stat_cpu(unsigned int cpu)191 u64 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_MCE
215 sum += per_cpu(mce_exception_count, cpu);
216 sum += per_cpu(mce_poll_count, cpu);
217 #endif
218 return sum;
219 }
220
arch_irq_stat(void)221 u64 arch_irq_stat(void)
222 {
223 u64 sum = atomic_read(&irq_err_count);
224 return sum;
225 }
226
227
228 /*
229 * do_IRQ handles all normal device IRQ's (the special
230 * SMP cross-CPU interrupts have their own specific
231 * handlers).
232 */
do_IRQ(struct pt_regs * regs)233 __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
234 {
235 struct pt_regs *old_regs = set_irq_regs(regs);
236 struct irq_desc * desc;
237 /* high bit used in ret_from_ code */
238 unsigned vector = ~regs->orig_ax;
239
240 entering_irq();
241
242 /* entering_irq() tells RCU that we're not quiescent. Check it. */
243 RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
244
245 desc = __this_cpu_read(vector_irq[vector]);
246 if (likely(!IS_ERR_OR_NULL(desc))) {
247 if (IS_ENABLED(CONFIG_X86_32))
248 handle_irq(desc, regs);
249 else
250 generic_handle_irq_desc(desc);
251 } else {
252 ack_APIC_irq();
253
254 if (desc == VECTOR_UNUSED) {
255 pr_emerg_ratelimited("%s: %d.%d No irq handler for vector\n",
256 __func__, smp_processor_id(),
257 vector);
258 } else {
259 __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
260 }
261 }
262
263 exiting_irq();
264
265 set_irq_regs(old_regs);
266 return 1;
267 }
268
269 #ifdef CONFIG_X86_LOCAL_APIC
270 /* Function pointer for generic interrupt vector handling */
271 void (*x86_platform_ipi_callback)(void) = NULL;
272 /*
273 * Handler for X86_PLATFORM_IPI_VECTOR.
274 */
smp_x86_platform_ipi(struct pt_regs * regs)275 __visible void __irq_entry smp_x86_platform_ipi(struct pt_regs *regs)
276 {
277 struct pt_regs *old_regs = set_irq_regs(regs);
278
279 entering_ack_irq();
280 trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
281 inc_irq_stat(x86_platform_ipis);
282 if (x86_platform_ipi_callback)
283 x86_platform_ipi_callback();
284 trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
285 exiting_irq();
286 set_irq_regs(old_regs);
287 }
288 #endif
289
290 #ifdef CONFIG_HAVE_KVM
dummy_handler(void)291 static void dummy_handler(void) {}
292 static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;
293
kvm_set_posted_intr_wakeup_handler(void (* handler)(void))294 void kvm_set_posted_intr_wakeup_handler(void (*handler)(void))
295 {
296 if (handler)
297 kvm_posted_intr_wakeup_handler = handler;
298 else {
299 kvm_posted_intr_wakeup_handler = dummy_handler;
300 synchronize_rcu();
301 }
302 }
303 EXPORT_SYMBOL_GPL(kvm_set_posted_intr_wakeup_handler);
304
305 /*
306 * Handler for POSTED_INTERRUPT_VECTOR.
307 */
smp_kvm_posted_intr_ipi(struct pt_regs * regs)308 __visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
309 {
310 struct pt_regs *old_regs = set_irq_regs(regs);
311
312 entering_ack_irq();
313 inc_irq_stat(kvm_posted_intr_ipis);
314 exiting_irq();
315 set_irq_regs(old_regs);
316 }
317
318 /*
319 * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
320 */
smp_kvm_posted_intr_wakeup_ipi(struct pt_regs * regs)321 __visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs)
322 {
323 struct pt_regs *old_regs = set_irq_regs(regs);
324
325 entering_ack_irq();
326 inc_irq_stat(kvm_posted_intr_wakeup_ipis);
327 kvm_posted_intr_wakeup_handler();
328 exiting_irq();
329 set_irq_regs(old_regs);
330 }
331
332 /*
333 * Handler for POSTED_INTERRUPT_NESTED_VECTOR.
334 */
smp_kvm_posted_intr_nested_ipi(struct pt_regs * regs)335 __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs)
336 {
337 struct pt_regs *old_regs = set_irq_regs(regs);
338
339 entering_ack_irq();
340 inc_irq_stat(kvm_posted_intr_nested_ipis);
341 exiting_irq();
342 set_irq_regs(old_regs);
343 }
344 #endif
345
346
347 #ifdef CONFIG_HOTPLUG_CPU
348 /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
fixup_irqs(void)349 void fixup_irqs(void)
350 {
351 unsigned int irr, vector;
352 struct irq_desc *desc;
353 struct irq_data *data;
354 struct irq_chip *chip;
355
356 irq_migrate_all_off_this_cpu();
357
358 /*
359 * We can remove mdelay() and then send spuriuous interrupts to
360 * new cpu targets for all the irqs that were handled previously by
361 * this cpu. While it works, I have seen spurious interrupt messages
362 * (nothing wrong but still...).
363 *
364 * So for now, retain mdelay(1) and check the IRR and then send those
365 * interrupts to new targets as this cpu is already offlined...
366 */
367 mdelay(1);
368
369 /*
370 * We can walk the vector array of this cpu without holding
371 * vector_lock because the cpu is already marked !online, so
372 * nothing else will touch it.
373 */
374 for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
375 if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector])))
376 continue;
377
378 irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
379 if (irr & (1 << (vector % 32))) {
380 desc = __this_cpu_read(vector_irq[vector]);
381
382 raw_spin_lock(&desc->lock);
383 data = irq_desc_get_irq_data(desc);
384 chip = irq_data_get_irq_chip(data);
385 if (chip->irq_retrigger) {
386 chip->irq_retrigger(data);
387 __this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
388 }
389 raw_spin_unlock(&desc->lock);
390 }
391 if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
392 __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
393 }
394 }
395 #endif
396