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v5.4
  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
 26DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
 27EXPORT_PER_CPU_SYMBOL(irq_stat);
 28
 29DEFINE_PER_CPU(struct pt_regs *, irq_regs);
 30EXPORT_PER_CPU_SYMBOL(irq_regs);
 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	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 */
 59int 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 */
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_MCE
215	sum += per_cpu(mce_exception_count, cpu);
216	sum += per_cpu(mce_poll_count, cpu);
217#endif
218	return sum;
219}
220
221u64 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 */
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 */
271void (*x86_platform_ipi_callback)(void) = NULL;
272/*
273 * Handler for X86_PLATFORM_IPI_VECTOR.
274 */
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
291static void dummy_handler(void) {}
292static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;
293
294void 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}
301EXPORT_SYMBOL_GPL(kvm_set_posted_intr_wakeup_handler);
302
303/*
304 * Handler for POSTED_INTERRUPT_VECTOR.
305 */
306__visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
307{
308	struct pt_regs *old_regs = set_irq_regs(regs);
309
310	entering_ack_irq();
311	inc_irq_stat(kvm_posted_intr_ipis);
312	exiting_irq();
313	set_irq_regs(old_regs);
314}
315
316/*
317 * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
318 */
319__visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs)
320{
321	struct pt_regs *old_regs = set_irq_regs(regs);
322
323	entering_ack_irq();
324	inc_irq_stat(kvm_posted_intr_wakeup_ipis);
325	kvm_posted_intr_wakeup_handler();
326	exiting_irq();
327	set_irq_regs(old_regs);
328}
329
330/*
331 * Handler for POSTED_INTERRUPT_NESTED_VECTOR.
332 */
333__visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs)
334{
335	struct pt_regs *old_regs = set_irq_regs(regs);
336
337	entering_ack_irq();
338	inc_irq_stat(kvm_posted_intr_nested_ipis);
339	exiting_irq();
340	set_irq_regs(old_regs);
341}
342#endif
343
 
344
345#ifdef CONFIG_HOTPLUG_CPU
346/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
347void fixup_irqs(void)
348{
349	unsigned int irr, vector;
 
350	struct irq_desc *desc;
351	struct irq_data *data;
352	struct irq_chip *chip;
353
354	irq_migrate_all_off_this_cpu();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
355
356	/*
357	 * We can remove mdelay() and then send spuriuous interrupts to
358	 * new cpu targets for all the irqs that were handled previously by
359	 * this cpu. While it works, I have seen spurious interrupt messages
360	 * (nothing wrong but still...).
361	 *
362	 * So for now, retain mdelay(1) and check the IRR and then send those
363	 * interrupts to new targets as this cpu is already offlined...
364	 */
365	mdelay(1);
366
367	/*
368	 * We can walk the vector array of this cpu without holding
369	 * vector_lock because the cpu is already marked !online, so
370	 * nothing else will touch it.
371	 */
372	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
373		if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector])))
 
 
374			continue;
375
376		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
377		if (irr  & (1 << (vector % 32))) {
378			desc = __this_cpu_read(vector_irq[vector]);
379
380			raw_spin_lock(&desc->lock);
381			data = irq_desc_get_irq_data(desc);
382			chip = irq_data_get_irq_chip(data);
383			if (chip->irq_retrigger) {
 
384				chip->irq_retrigger(data);
385				__this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
386			}
387			raw_spin_unlock(&desc->lock);
388		}
389		if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
390			__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
391	}
392}
393#endif
v3.1
 
  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
 13#include <asm/apic.h>
 14#include <asm/io_apic.h>
 15#include <asm/irq.h>
 16#include <asm/idle.h>
 17#include <asm/mce.h>
 18#include <asm/hw_irq.h>
 
 
 
 
 
 
 
 
 
 
 19
 20atomic_t irq_err_count;
 21
 22/* Function pointer for generic interrupt vector handling */
 23void (*x86_platform_ipi_callback)(void) = NULL;
 24
 25/*
 26 * 'what should we do if we get a hw irq event on an illegal vector'.
 27 * each architecture has to answer this themselves.
 28 */
 29void ack_bad_irq(unsigned int irq)
 30{
 31	if (printk_ratelimit())
 32		pr_err("unexpected IRQ trap at vector %02x\n", irq);
 33
 34	/*
 35	 * Currently unexpected vectors happen only on SMP and APIC.
 36	 * We _must_ ack these because every local APIC has only N
 37	 * irq slots per priority level, and a 'hanging, unacked' IRQ
 38	 * holds up an irq slot - in excessive cases (when multiple
 39	 * unexpected vectors occur) that might lock up the APIC
 40	 * completely.
 41	 * But only ack when the APIC is enabled -AK
 42	 */
 43	ack_APIC_irq();
 44}
 45
 46#define irq_stats(x)		(&per_cpu(irq_stat, x))
 47/*
 48 * /proc/interrupts printing for arch specific interrupts
 49 */
 50int arch_show_interrupts(struct seq_file *p, int prec)
 51{
 52	int j;
 53
 54	seq_printf(p, "%*s: ", prec, "NMI");
 55	for_each_online_cpu(j)
 56		seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
 57	seq_printf(p, "  Non-maskable interrupts\n");
 58#ifdef CONFIG_X86_LOCAL_APIC
 59	seq_printf(p, "%*s: ", prec, "LOC");
 60	for_each_online_cpu(j)
 61		seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
 62	seq_printf(p, "  Local timer interrupts\n");
 63
 64	seq_printf(p, "%*s: ", prec, "SPU");
 65	for_each_online_cpu(j)
 66		seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
 67	seq_printf(p, "  Spurious interrupts\n");
 68	seq_printf(p, "%*s: ", prec, "PMI");
 69	for_each_online_cpu(j)
 70		seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
 71	seq_printf(p, "  Performance monitoring interrupts\n");
 72	seq_printf(p, "%*s: ", prec, "IWI");
 73	for_each_online_cpu(j)
 74		seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
 75	seq_printf(p, "  IRQ work interrupts\n");
 76#endif
 
 
 
 77	if (x86_platform_ipi_callback) {
 78		seq_printf(p, "%*s: ", prec, "PLT");
 79		for_each_online_cpu(j)
 80			seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
 81		seq_printf(p, "  Platform interrupts\n");
 82	}
 
 83#ifdef CONFIG_SMP
 84	seq_printf(p, "%*s: ", prec, "RES");
 85	for_each_online_cpu(j)
 86		seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
 87	seq_printf(p, "  Rescheduling interrupts\n");
 88	seq_printf(p, "%*s: ", prec, "CAL");
 89	for_each_online_cpu(j)
 90		seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
 91	seq_printf(p, "  Function call interrupts\n");
 92	seq_printf(p, "%*s: ", prec, "TLB");
 93	for_each_online_cpu(j)
 94		seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
 95	seq_printf(p, "  TLB shootdowns\n");
 96#endif
 97#ifdef CONFIG_X86_THERMAL_VECTOR
 98	seq_printf(p, "%*s: ", prec, "TRM");
 99	for_each_online_cpu(j)
100		seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
101	seq_printf(p, "  Thermal event interrupts\n");
102#endif
103#ifdef CONFIG_X86_MCE_THRESHOLD
104	seq_printf(p, "%*s: ", prec, "THR");
105	for_each_online_cpu(j)
106		seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
107	seq_printf(p, "  Threshold APIC interrupts\n");
 
 
 
 
 
 
108#endif
109#ifdef CONFIG_X86_MCE
110	seq_printf(p, "%*s: ", prec, "MCE");
111	for_each_online_cpu(j)
112		seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
113	seq_printf(p, "  Machine check exceptions\n");
114	seq_printf(p, "%*s: ", prec, "MCP");
115	for_each_online_cpu(j)
116		seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
117	seq_printf(p, "  Machine check polls\n");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
118#endif
119	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
120#if defined(CONFIG_X86_IO_APIC)
121	seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
122#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
123	return 0;
124}
125
126/*
127 * /proc/stat helpers
128 */
129u64 arch_irq_stat_cpu(unsigned int cpu)
130{
131	u64 sum = irq_stats(cpu)->__nmi_count;
132
133#ifdef CONFIG_X86_LOCAL_APIC
134	sum += irq_stats(cpu)->apic_timer_irqs;
135	sum += irq_stats(cpu)->irq_spurious_count;
136	sum += irq_stats(cpu)->apic_perf_irqs;
137	sum += irq_stats(cpu)->apic_irq_work_irqs;
138#endif
139	if (x86_platform_ipi_callback)
140		sum += irq_stats(cpu)->x86_platform_ipis;
 
141#ifdef CONFIG_SMP
142	sum += irq_stats(cpu)->irq_resched_count;
143	sum += irq_stats(cpu)->irq_call_count;
144	sum += irq_stats(cpu)->irq_tlb_count;
145#endif
146#ifdef CONFIG_X86_THERMAL_VECTOR
147	sum += irq_stats(cpu)->irq_thermal_count;
148#endif
149#ifdef CONFIG_X86_MCE_THRESHOLD
150	sum += irq_stats(cpu)->irq_threshold_count;
151#endif
152#ifdef CONFIG_X86_MCE
153	sum += per_cpu(mce_exception_count, cpu);
154	sum += per_cpu(mce_poll_count, cpu);
155#endif
156	return sum;
157}
158
159u64 arch_irq_stat(void)
160{
161	u64 sum = atomic_read(&irq_err_count);
162
163#ifdef CONFIG_X86_IO_APIC
164	sum += atomic_read(&irq_mis_count);
165#endif
166	return sum;
167}
168
169
170/*
171 * do_IRQ handles all normal device IRQ's (the special
172 * SMP cross-CPU interrupts have their own specific
173 * handlers).
174 */
175unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
176{
177	struct pt_regs *old_regs = set_irq_regs(regs);
178
179	/* high bit used in ret_from_ code  */
180	unsigned vector = ~regs->orig_ax;
181	unsigned irq;
182
183	exit_idle();
184	irq_enter();
185
186	irq = __this_cpu_read(vector_irq[vector]);
 
187
188	if (!handle_irq(irq, regs)) {
 
 
 
 
 
 
189		ack_APIC_irq();
190
191		if (printk_ratelimit())
192			pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n",
193				__func__, smp_processor_id(), vector, irq);
 
 
 
 
194	}
195
196	irq_exit();
197
198	set_irq_regs(old_regs);
199	return 1;
200}
201
 
 
 
202/*
203 * Handler for X86_PLATFORM_IPI_VECTOR.
204 */
205void smp_x86_platform_ipi(struct pt_regs *regs)
206{
207	struct pt_regs *old_regs = set_irq_regs(regs);
208
209	ack_APIC_irq();
 
 
 
 
 
 
 
 
 
 
 
 
 
210
211	exit_idle();
 
 
 
 
 
 
 
212
213	irq_enter();
 
 
 
 
 
214
215	inc_irq_stat(x86_platform_ipis);
 
 
 
 
216
217	if (x86_platform_ipi_callback)
218		x86_platform_ipi_callback();
 
 
 
 
219
220	irq_exit();
 
 
 
 
 
221
 
 
 
 
 
 
 
 
 
 
222	set_irq_regs(old_regs);
223}
 
224
225EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
226
227#ifdef CONFIG_HOTPLUG_CPU
228/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
229void fixup_irqs(void)
230{
231	unsigned int irq, vector;
232	static int warned;
233	struct irq_desc *desc;
234	struct irq_data *data;
235	struct irq_chip *chip;
236
237	for_each_irq_desc(irq, desc) {
238		int break_affinity = 0;
239		int set_affinity = 1;
240		const struct cpumask *affinity;
241
242		if (!desc)
243			continue;
244		if (irq == 2)
245			continue;
246
247		/* interrupt's are disabled at this point */
248		raw_spin_lock(&desc->lock);
249
250		data = irq_desc_get_irq_data(desc);
251		affinity = data->affinity;
252		if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
253		    cpumask_subset(affinity, cpu_online_mask)) {
254			raw_spin_unlock(&desc->lock);
255			continue;
256		}
257
258		/*
259		 * Complete the irq move. This cpu is going down and for
260		 * non intr-remapping case, we can't wait till this interrupt
261		 * arrives at this cpu before completing the irq move.
262		 */
263		irq_force_complete_move(irq);
264
265		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
266			break_affinity = 1;
267			affinity = cpu_all_mask;
268		}
269
270		chip = irq_data_get_irq_chip(data);
271		if (!irqd_can_move_in_process_context(data) && chip->irq_mask)
272			chip->irq_mask(data);
273
274		if (chip->irq_set_affinity)
275			chip->irq_set_affinity(data, affinity, true);
276		else if (!(warned++))
277			set_affinity = 0;
278
279		if (!irqd_can_move_in_process_context(data) &&
280		    !irqd_irq_disabled(data) && chip->irq_unmask)
281			chip->irq_unmask(data);
282
283		raw_spin_unlock(&desc->lock);
284
285		if (break_affinity && set_affinity)
286			printk("Broke affinity for irq %i\n", irq);
287		else if (!set_affinity)
288			printk("Cannot set affinity for irq %i\n", irq);
289	}
290
291	/*
292	 * We can remove mdelay() and then send spuriuous interrupts to
293	 * new cpu targets for all the irqs that were handled previously by
294	 * this cpu. While it works, I have seen spurious interrupt messages
295	 * (nothing wrong but still...).
296	 *
297	 * So for now, retain mdelay(1) and check the IRR and then send those
298	 * interrupts to new targets as this cpu is already offlined...
299	 */
300	mdelay(1);
301
 
 
 
 
 
302	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
303		unsigned int irr;
304
305		if (__this_cpu_read(vector_irq[vector]) < 0)
306			continue;
307
308		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
309		if (irr  & (1 << (vector % 32))) {
310			irq = __this_cpu_read(vector_irq[vector]);
311
312			desc = irq_to_desc(irq);
313			data = irq_desc_get_irq_data(desc);
314			chip = irq_data_get_irq_chip(data);
315			raw_spin_lock(&desc->lock);
316			if (chip->irq_retrigger)
317				chip->irq_retrigger(data);
 
 
318			raw_spin_unlock(&desc->lock);
319		}
 
 
320	}
321}
322#endif