xref: /openbmc/linux/arch/x86/kernel/irq.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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/seq_file.h>
8 #include <linux/smp.h>
9 #include <linux/ftrace.h>
10 
11 #include <asm/apic.h>
12 #include <asm/io_apic.h>
13 #include <asm/irq.h>
14 #include <asm/idle.h>
15 
16 atomic_t irq_err_count;
17 
18 /* Function pointer for generic interrupt vector handling */
19 void (*generic_interrupt_extension)(void) = NULL;
20 
21 /*
22  * 'what should we do if we get a hw irq event on an illegal vector'.
23  * each architecture has to answer this themselves.
24  */
25 void ack_bad_irq(unsigned int irq)
26 {
27 	printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
28 
29 #ifdef CONFIG_X86_LOCAL_APIC
30 	/*
31 	 * Currently unexpected vectors happen only on SMP and APIC.
32 	 * We _must_ ack these because every local APIC has only N
33 	 * irq slots per priority level, and a 'hanging, unacked' IRQ
34 	 * holds up an irq slot - in excessive cases (when multiple
35 	 * unexpected vectors occur) that might lock up the APIC
36 	 * completely.
37 	 * But only ack when the APIC is enabled -AK
38 	 */
39 	if (cpu_has_apic)
40 		ack_APIC_irq();
41 #endif
42 }
43 
44 #define irq_stats(x)		(&per_cpu(irq_stat, x))
45 /*
46  * /proc/interrupts printing:
47  */
48 static int show_other_interrupts(struct seq_file *p, int prec)
49 {
50 	int j;
51 
52 	seq_printf(p, "%*s: ", prec, "NMI");
53 	for_each_online_cpu(j)
54 		seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
55 	seq_printf(p, "  Non-maskable interrupts\n");
56 #ifdef CONFIG_X86_LOCAL_APIC
57 	seq_printf(p, "%*s: ", prec, "LOC");
58 	for_each_online_cpu(j)
59 		seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
60 	seq_printf(p, "  Local timer interrupts\n");
61 
62 	seq_printf(p, "%*s: ", prec, "SPU");
63 	for_each_online_cpu(j)
64 		seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
65 	seq_printf(p, "  Spurious interrupts\n");
66 #endif
67 	if (generic_interrupt_extension) {
68 		seq_printf(p, "PLT: ");
69 		for_each_online_cpu(j)
70 			seq_printf(p, "%10u ", irq_stats(j)->generic_irqs);
71 		seq_printf(p, "  Platform interrupts\n");
72 	}
73 #ifdef CONFIG_SMP
74 	seq_printf(p, "%*s: ", prec, "RES");
75 	for_each_online_cpu(j)
76 		seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
77 	seq_printf(p, "  Rescheduling interrupts\n");
78 	seq_printf(p, "%*s: ", prec, "CAL");
79 	for_each_online_cpu(j)
80 		seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
81 	seq_printf(p, "  Function call interrupts\n");
82 	seq_printf(p, "%*s: ", prec, "TLB");
83 	for_each_online_cpu(j)
84 		seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
85 	seq_printf(p, "  TLB shootdowns\n");
86 #endif
87 #ifdef CONFIG_X86_MCE
88 	seq_printf(p, "%*s: ", prec, "TRM");
89 	for_each_online_cpu(j)
90 		seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
91 	seq_printf(p, "  Thermal event interrupts\n");
92 # ifdef CONFIG_X86_64
93 	seq_printf(p, "%*s: ", prec, "THR");
94 	for_each_online_cpu(j)
95 		seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
96 	seq_printf(p, "  Threshold APIC interrupts\n");
97 # endif
98 #endif
99 	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
100 #if defined(CONFIG_X86_IO_APIC)
101 	seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
102 #endif
103 	return 0;
104 }
105 
106 int show_interrupts(struct seq_file *p, void *v)
107 {
108 	unsigned long flags, any_count = 0;
109 	int i = *(loff_t *) v, j, prec;
110 	struct irqaction *action;
111 	struct irq_desc *desc;
112 
113 	if (i > nr_irqs)
114 		return 0;
115 
116 	for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
117 		j *= 10;
118 
119 	if (i == nr_irqs)
120 		return show_other_interrupts(p, prec);
121 
122 	/* print header */
123 	if (i == 0) {
124 		seq_printf(p, "%*s", prec + 8, "");
125 		for_each_online_cpu(j)
126 			seq_printf(p, "CPU%-8d", j);
127 		seq_putc(p, '\n');
128 	}
129 
130 	desc = irq_to_desc(i);
131 	if (!desc)
132 		return 0;
133 
134 	spin_lock_irqsave(&desc->lock, flags);
135 	for_each_online_cpu(j)
136 		any_count |= kstat_irqs_cpu(i, j);
137 	action = desc->action;
138 	if (!action && !any_count)
139 		goto out;
140 
141 	seq_printf(p, "%*d: ", prec, i);
142 	for_each_online_cpu(j)
143 		seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
144 	seq_printf(p, " %8s", desc->chip->name);
145 	seq_printf(p, "-%-8s", desc->name);
146 
147 	if (action) {
148 		seq_printf(p, "  %s", action->name);
149 		while ((action = action->next) != NULL)
150 			seq_printf(p, ", %s", action->name);
151 	}
152 
153 	seq_putc(p, '\n');
154 out:
155 	spin_unlock_irqrestore(&desc->lock, flags);
156 	return 0;
157 }
158 
159 /*
160  * /proc/stat helpers
161  */
162 u64 arch_irq_stat_cpu(unsigned int cpu)
163 {
164 	u64 sum = irq_stats(cpu)->__nmi_count;
165 
166 #ifdef CONFIG_X86_LOCAL_APIC
167 	sum += irq_stats(cpu)->apic_timer_irqs;
168 	sum += irq_stats(cpu)->irq_spurious_count;
169 #endif
170 	if (generic_interrupt_extension)
171 		sum += irq_stats(cpu)->generic_irqs;
172 #ifdef CONFIG_SMP
173 	sum += irq_stats(cpu)->irq_resched_count;
174 	sum += irq_stats(cpu)->irq_call_count;
175 	sum += irq_stats(cpu)->irq_tlb_count;
176 #endif
177 #ifdef CONFIG_X86_MCE
178 	sum += irq_stats(cpu)->irq_thermal_count;
179 # ifdef CONFIG_X86_64
180 	sum += irq_stats(cpu)->irq_threshold_count;
181 #endif
182 #endif
183 	return sum;
184 }
185 
186 u64 arch_irq_stat(void)
187 {
188 	u64 sum = atomic_read(&irq_err_count);
189 
190 #ifdef CONFIG_X86_IO_APIC
191 	sum += atomic_read(&irq_mis_count);
192 #endif
193 	return sum;
194 }
195 
196 
197 /*
198  * do_IRQ handles all normal device IRQ's (the special
199  * SMP cross-CPU interrupts have their own specific
200  * handlers).
201  */
202 unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
203 {
204 	struct pt_regs *old_regs = set_irq_regs(regs);
205 
206 	/* high bit used in ret_from_ code  */
207 	unsigned vector = ~regs->orig_ax;
208 	unsigned irq;
209 
210 	exit_idle();
211 	irq_enter();
212 
213 	irq = __get_cpu_var(vector_irq)[vector];
214 
215 	if (!handle_irq(irq, regs)) {
216 #ifdef CONFIG_X86_64
217 		if (!disable_apic)
218 			ack_APIC_irq();
219 #endif
220 
221 		if (printk_ratelimit())
222 			printk(KERN_EMERG "%s: %d.%d No irq handler for vector (irq %d)\n",
223 			       __func__, smp_processor_id(), vector, irq);
224 	}
225 
226 	irq_exit();
227 
228 	set_irq_regs(old_regs);
229 	return 1;
230 }
231 
232 /*
233  * Handler for GENERIC_INTERRUPT_VECTOR.
234  */
235 void smp_generic_interrupt(struct pt_regs *regs)
236 {
237 	struct pt_regs *old_regs = set_irq_regs(regs);
238 
239 	ack_APIC_irq();
240 
241 	exit_idle();
242 
243 	irq_enter();
244 
245 	inc_irq_stat(generic_irqs);
246 
247 	if (generic_interrupt_extension)
248 		generic_interrupt_extension();
249 
250 	irq_exit();
251 
252 	set_irq_regs(old_regs);
253 }
254 
255 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
256