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#include <asm/desc.h>
21
22#define CREATE_TRACE_POINTS
23#include <asm/trace/irq_vectors.h>
24
25atomic_t irq_err_count;
26
27/* Function pointer for generic interrupt vector handling */
28void (*x86_platform_ipi_callback)(void) = NULL;
29
30/*
31 * 'what should we do if we get a hw irq event on an illegal vector'.
32 * each architecture has to answer this themselves.
33 */
34void ack_bad_irq(unsigned int irq)
35{
36	if (printk_ratelimit())
37		pr_err("unexpected IRQ trap at vector %02x\n", irq);
38
39	/*
40	 * Currently unexpected vectors happen only on SMP and APIC.
41	 * We _must_ ack these because every local APIC has only N
42	 * irq slots per priority level, and a 'hanging, unacked' IRQ
43	 * holds up an irq slot - in excessive cases (when multiple
44	 * unexpected vectors occur) that might lock up the APIC
45	 * completely.
46	 * But only ack when the APIC is enabled -AK
47	 */
48	ack_APIC_irq();
49}
50
51#define irq_stats(x)		(&per_cpu(irq_stat, x))
52/*
53 * /proc/interrupts printing for arch specific interrupts
54 */
55int arch_show_interrupts(struct seq_file *p, int prec)
56{
57	int j;
58
59	seq_printf(p, "%*s: ", prec, "NMI");
60	for_each_online_cpu(j)
61		seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
62	seq_puts(p, "  Non-maskable interrupts\n");
63#ifdef CONFIG_X86_LOCAL_APIC
64	seq_printf(p, "%*s: ", prec, "LOC");
65	for_each_online_cpu(j)
66		seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
67	seq_puts(p, "  Local timer interrupts\n");
68
69	seq_printf(p, "%*s: ", prec, "SPU");
70	for_each_online_cpu(j)
71		seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
72	seq_puts(p, "  Spurious interrupts\n");
73	seq_printf(p, "%*s: ", prec, "PMI");
74	for_each_online_cpu(j)
75		seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
76	seq_puts(p, "  Performance monitoring interrupts\n");
77	seq_printf(p, "%*s: ", prec, "IWI");
78	for_each_online_cpu(j)
79		seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
80	seq_puts(p, "  IRQ work interrupts\n");
81	seq_printf(p, "%*s: ", prec, "RTR");
82	for_each_online_cpu(j)
83		seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
84	seq_puts(p, "  APIC ICR read retries\n");
85#endif
86	if (x86_platform_ipi_callback) {
87		seq_printf(p, "%*s: ", prec, "PLT");
88		for_each_online_cpu(j)
89			seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
90		seq_puts(p, "  Platform interrupts\n");
91	}
92#ifdef CONFIG_SMP
93	seq_printf(p, "%*s: ", prec, "RES");
94	for_each_online_cpu(j)
95		seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
96	seq_puts(p, "  Rescheduling interrupts\n");
97	seq_printf(p, "%*s: ", prec, "CAL");
98	for_each_online_cpu(j)
99		seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
100					irq_stats(j)->irq_tlb_count);
101	seq_puts(p, "  Function call interrupts\n");
102	seq_printf(p, "%*s: ", prec, "TLB");
103	for_each_online_cpu(j)
104		seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
105	seq_puts(p, "  TLB shootdowns\n");
106#endif
107#ifdef CONFIG_X86_THERMAL_VECTOR
108	seq_printf(p, "%*s: ", prec, "TRM");
109	for_each_online_cpu(j)
110		seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
111	seq_puts(p, "  Thermal event interrupts\n");
112#endif
113#ifdef CONFIG_X86_MCE_THRESHOLD
114	seq_printf(p, "%*s: ", prec, "THR");
115	for_each_online_cpu(j)
116		seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
117	seq_puts(p, "  Threshold APIC interrupts\n");
118#endif
119#ifdef CONFIG_X86_MCE
120	seq_printf(p, "%*s: ", prec, "MCE");
121	for_each_online_cpu(j)
122		seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
123	seq_puts(p, "  Machine check exceptions\n");
124	seq_printf(p, "%*s: ", prec, "MCP");
125	for_each_online_cpu(j)
126		seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
127	seq_puts(p, "  Machine check polls\n");
128#endif
129#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
130	seq_printf(p, "%*s: ", prec, "HYP");
131	for_each_online_cpu(j)
132		seq_printf(p, "%10u ", irq_stats(j)->irq_hv_callback_count);
133	seq_puts(p, "  Hypervisor callback interrupts\n");
134#endif
135	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
136#if defined(CONFIG_X86_IO_APIC)
137	seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
138#endif
139	return 0;
140}
141
142/*
143 * /proc/stat helpers
144 */
145u64 arch_irq_stat_cpu(unsigned int cpu)
146{
147	u64 sum = irq_stats(cpu)->__nmi_count;
148
149#ifdef CONFIG_X86_LOCAL_APIC
150	sum += irq_stats(cpu)->apic_timer_irqs;
151	sum += irq_stats(cpu)->irq_spurious_count;
152	sum += irq_stats(cpu)->apic_perf_irqs;
153	sum += irq_stats(cpu)->apic_irq_work_irqs;
154	sum += irq_stats(cpu)->icr_read_retry_count;
155#endif
156	if (x86_platform_ipi_callback)
157		sum += irq_stats(cpu)->x86_platform_ipis;
158#ifdef CONFIG_SMP
159	sum += irq_stats(cpu)->irq_resched_count;
160	sum += irq_stats(cpu)->irq_call_count;
161#endif
162#ifdef CONFIG_X86_THERMAL_VECTOR
163	sum += irq_stats(cpu)->irq_thermal_count;
164#endif
165#ifdef CONFIG_X86_MCE_THRESHOLD
166	sum += irq_stats(cpu)->irq_threshold_count;
167#endif
168#ifdef CONFIG_X86_MCE
169	sum += per_cpu(mce_exception_count, cpu);
170	sum += per_cpu(mce_poll_count, cpu);
171#endif
172	return sum;
173}
174
175u64 arch_irq_stat(void)
176{
177	u64 sum = atomic_read(&irq_err_count);
178	return sum;
179}
180
181
182/*
183 * do_IRQ handles all normal device IRQ's (the special
184 * SMP cross-CPU interrupts have their own specific
185 * handlers).
186 */
187__visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
188{
189	struct pt_regs *old_regs = set_irq_regs(regs);
190
191	/* high bit used in ret_from_ code  */
192	unsigned vector = ~regs->orig_ax;
193	unsigned irq;
194
195	irq_enter();
196	exit_idle();
197
198	irq = __this_cpu_read(vector_irq[vector]);
199
200	if (!handle_irq(irq, regs)) {
201		ack_APIC_irq();
202
203		if (irq != VECTOR_RETRIGGERED) {
204			pr_emerg_ratelimited("%s: %d.%d No irq handler for vector (irq %d)\n",
205					     __func__, smp_processor_id(),
206					     vector, irq);
207		} else {
208			__this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
209		}
210	}
211
212	irq_exit();
213
214	set_irq_regs(old_regs);
215	return 1;
216}
217
218/*
219 * Handler for X86_PLATFORM_IPI_VECTOR.
220 */
221void __smp_x86_platform_ipi(void)
222{
223	inc_irq_stat(x86_platform_ipis);
224
225	if (x86_platform_ipi_callback)
226		x86_platform_ipi_callback();
227}
228
229__visible void smp_x86_platform_ipi(struct pt_regs *regs)
230{
231	struct pt_regs *old_regs = set_irq_regs(regs);
232
233	entering_ack_irq();
234	__smp_x86_platform_ipi();
235	exiting_irq();
236	set_irq_regs(old_regs);
237}
238
239#ifdef CONFIG_HAVE_KVM
240/*
241 * Handler for POSTED_INTERRUPT_VECTOR.
242 */
243__visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
244{
245	struct pt_regs *old_regs = set_irq_regs(regs);
246
247	ack_APIC_irq();
248
249	irq_enter();
250
251	exit_idle();
252
253	inc_irq_stat(kvm_posted_intr_ipis);
254
255	irq_exit();
256
257	set_irq_regs(old_regs);
258}
259#endif
260
261__visible void smp_trace_x86_platform_ipi(struct pt_regs *regs)
262{
263	struct pt_regs *old_regs = set_irq_regs(regs);
264
265	entering_ack_irq();
266	trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
267	__smp_x86_platform_ipi();
268	trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
269	exiting_irq();
270	set_irq_regs(old_regs);
271}
272
273EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
274
275#ifdef CONFIG_HOTPLUG_CPU
276
277/* These two declarations are only used in check_irq_vectors_for_cpu_disable()
278 * below, which is protected by stop_machine().  Putting them on the stack
279 * results in a stack frame overflow.  Dynamically allocating could result in a
280 * failure so declare these two cpumasks as global.
281 */
282static struct cpumask affinity_new, online_new;
283
284/*
285 * This cpu is going to be removed and its vectors migrated to the remaining
286 * online cpus.  Check to see if there are enough vectors in the remaining cpus.
287 * This function is protected by stop_machine().
288 */
289int check_irq_vectors_for_cpu_disable(void)
290{
291	int irq, cpu;
292	unsigned int this_cpu, vector, this_count, count;
293	struct irq_desc *desc;
294	struct irq_data *data;
295
296	this_cpu = smp_processor_id();
297	cpumask_copy(&online_new, cpu_online_mask);
298	cpumask_clear_cpu(this_cpu, &online_new);
299
300	this_count = 0;
301	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
302		irq = __this_cpu_read(vector_irq[vector]);
303		if (irq >= 0) {
304			desc = irq_to_desc(irq);
305			if (!desc)
306				continue;
307
308			data = irq_desc_get_irq_data(desc);
309			cpumask_copy(&affinity_new, data->affinity);
310			cpumask_clear_cpu(this_cpu, &affinity_new);
311
312			/* Do not count inactive or per-cpu irqs. */
313			if (!irq_has_action(irq) || irqd_is_per_cpu(data))
314				continue;
315
316			/*
317			 * A single irq may be mapped to multiple
318			 * cpu's vector_irq[] (for example IOAPIC cluster
319			 * mode).  In this case we have two
320			 * possibilities:
321			 *
322			 * 1) the resulting affinity mask is empty; that is
323			 * this the down'd cpu is the last cpu in the irq's
324			 * affinity mask, or
325			 *
326			 * 2) the resulting affinity mask is no longer
327			 * a subset of the online cpus but the affinity
328			 * mask is not zero; that is the down'd cpu is the
329			 * last online cpu in a user set affinity mask.
330			 */
331			if (cpumask_empty(&affinity_new) ||
332			    !cpumask_subset(&affinity_new, &online_new))
333				this_count++;
334		}
335	}
336
337	count = 0;
338	for_each_online_cpu(cpu) {
339		if (cpu == this_cpu)
340			continue;
341		/*
342		 * We scan from FIRST_EXTERNAL_VECTOR to first system
343		 * vector. If the vector is marked in the used vectors
344		 * bitmap or an irq is assigned to it, we don't count
345		 * it as available.
346		 */
347		for (vector = FIRST_EXTERNAL_VECTOR;
348		     vector < first_system_vector; vector++) {
349			if (!test_bit(vector, used_vectors) &&
350			    per_cpu(vector_irq, cpu)[vector] < 0)
351					count++;
352		}
353	}
354
355	if (count < this_count) {
356		pr_warn("CPU %d disable failed: CPU has %u vectors assigned and there are only %u available.\n",
357			this_cpu, this_count, count);
358		return -ERANGE;
359	}
360	return 0;
361}
362
363/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
364void fixup_irqs(void)
365{
366	unsigned int irq, vector;
367	static int warned;
368	struct irq_desc *desc;
369	struct irq_data *data;
370	struct irq_chip *chip;
371	int ret;
372
373	for_each_irq_desc(irq, desc) {
374		int break_affinity = 0;
375		int set_affinity = 1;
376		const struct cpumask *affinity;
377
378		if (!desc)
379			continue;
380		if (irq == 2)
381			continue;
382
383		/* interrupt's are disabled at this point */
384		raw_spin_lock(&desc->lock);
385
386		data = irq_desc_get_irq_data(desc);
387		affinity = data->affinity;
388		if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
389		    cpumask_subset(affinity, cpu_online_mask)) {
390			raw_spin_unlock(&desc->lock);
391			continue;
392		}
393
394		/*
395		 * Complete the irq move. This cpu is going down and for
396		 * non intr-remapping case, we can't wait till this interrupt
397		 * arrives at this cpu before completing the irq move.
398		 */
399		irq_force_complete_move(irq);
400
401		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
402			break_affinity = 1;
403			affinity = cpu_online_mask;
404		}
405
406		chip = irq_data_get_irq_chip(data);
407		if (!irqd_can_move_in_process_context(data) && chip->irq_mask)
408			chip->irq_mask(data);
409
410		if (chip->irq_set_affinity) {
411			ret = chip->irq_set_affinity(data, affinity, true);
412			if (ret == -ENOSPC)
413				pr_crit("IRQ %d set affinity failed because there are no available vectors.  The device assigned to this IRQ is unstable.\n", irq);
414		} else {
415			if (!(warned++))
416				set_affinity = 0;
417		}
418
419		/*
420		 * We unmask if the irq was not marked masked by the
421		 * core code. That respects the lazy irq disable
422		 * behaviour.
423		 */
424		if (!irqd_can_move_in_process_context(data) &&
425		    !irqd_irq_masked(data) && chip->irq_unmask)
426			chip->irq_unmask(data);
427
428		raw_spin_unlock(&desc->lock);
429
430		if (break_affinity && set_affinity)
431			pr_notice("Broke affinity for irq %i\n", irq);
432		else if (!set_affinity)
433			pr_notice("Cannot set affinity for irq %i\n", irq);
434	}
435
436	/*
437	 * We can remove mdelay() and then send spuriuous interrupts to
438	 * new cpu targets for all the irqs that were handled previously by
439	 * this cpu. While it works, I have seen spurious interrupt messages
440	 * (nothing wrong but still...).
441	 *
442	 * So for now, retain mdelay(1) and check the IRR and then send those
443	 * interrupts to new targets as this cpu is already offlined...
444	 */
445	mdelay(1);
446
447	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
448		unsigned int irr;
449
450		if (__this_cpu_read(vector_irq[vector]) <= VECTOR_UNDEFINED)
451			continue;
452
453		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
454		if (irr  & (1 << (vector % 32))) {
455			irq = __this_cpu_read(vector_irq[vector]);
456
457			desc = irq_to_desc(irq);
458			data = irq_desc_get_irq_data(desc);
459			chip = irq_data_get_irq_chip(data);
460			raw_spin_lock(&desc->lock);
461			if (chip->irq_retrigger) {
462				chip->irq_retrigger(data);
463				__this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
464			}
465			raw_spin_unlock(&desc->lock);
466		}
467		if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
468			__this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
469	}
470}
471#endif
472