xref: /linux/arch/x86/kernel/irq.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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 
20 atomic_t irq_err_count;
21 
22 /* Function pointer for generic interrupt vector handling */
23 void (*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  */
29 void 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  */
50 int 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  */
129 u64 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 
159 u64 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  */
175 unsigned 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  */
205 void 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 
225 EXPORT_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. */
229 void 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
323