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 
21 atomic_t irq_err_count;
22 
23 /* Function pointer for generic interrupt vector handling */
24 void (*x86_platform_ipi_callback)(void) = NULL;
25 
26 /*
27  * 'what should we do if we get a hw irq event on an illegal vector'.
28  * each architecture has to answer this themselves.
29  */
ack_bad_irq(unsigned int irq)30 void ack_bad_irq(unsigned int irq)
31 {
32 	if (printk_ratelimit())
33 		pr_err("unexpected IRQ trap at vector %02x\n", irq);
34 
35 	/*
36 	 * Currently unexpected vectors happen only on SMP and APIC.
37 	 * We _must_ ack these because every local APIC has only N
38 	 * irq slots per priority level, and a 'hanging, unacked' IRQ
39 	 * holds up an irq slot - in excessive cases (when multiple
40 	 * unexpected vectors occur) that might lock up the APIC
41 	 * completely.
42 	 * But only ack when the APIC is enabled -AK
43 	 */
44 	ack_APIC_irq();
45 }
46 
47 #define irq_stats(x)		(&per_cpu(irq_stat, x))
48 /*
49  * /proc/interrupts printing for arch specific interrupts
50  */
arch_show_interrupts(struct seq_file * p,int prec)51 int arch_show_interrupts(struct seq_file *p, int prec)
52 {
53 	int j;
54 
55 	seq_printf(p, "%*s: ", prec, "NMI");
56 	for_each_online_cpu(j)
57 		seq_printf(p, "%10u ", irq_stats(j)->__nmi_count);
58 	seq_printf(p, "  Non-maskable interrupts\n");
59 #ifdef CONFIG_X86_LOCAL_APIC
60 	seq_printf(p, "%*s: ", prec, "LOC");
61 	for_each_online_cpu(j)
62 		seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
63 	seq_printf(p, "  Local timer interrupts\n");
64 
65 	seq_printf(p, "%*s: ", prec, "SPU");
66 	for_each_online_cpu(j)
67 		seq_printf(p, "%10u ", irq_stats(j)->irq_spurious_count);
68 	seq_printf(p, "  Spurious interrupts\n");
69 	seq_printf(p, "%*s: ", prec, "PMI");
70 	for_each_online_cpu(j)
71 		seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
72 	seq_printf(p, "  Performance monitoring interrupts\n");
73 	seq_printf(p, "%*s: ", prec, "IWI");
74 	for_each_online_cpu(j)
75 		seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
76 	seq_printf(p, "  IRQ work interrupts\n");
77 	seq_printf(p, "%*s: ", prec, "RTR");
78 	for_each_online_cpu(j)
79 		seq_printf(p, "%10u ", irq_stats(j)->icr_read_retry_count);
80 	seq_printf(p, "  APIC ICR read retries\n");
81 #endif
82 	if (x86_platform_ipi_callback) {
83 		seq_printf(p, "%*s: ", prec, "PLT");
84 		for_each_online_cpu(j)
85 			seq_printf(p, "%10u ", irq_stats(j)->x86_platform_ipis);
86 		seq_printf(p, "  Platform interrupts\n");
87 	}
88 #ifdef CONFIG_SMP
89 	seq_printf(p, "%*s: ", prec, "RES");
90 	for_each_online_cpu(j)
91 		seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
92 	seq_printf(p, "  Rescheduling interrupts\n");
93 	seq_printf(p, "%*s: ", prec, "CAL");
94 	for_each_online_cpu(j)
95 		seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
96 	seq_printf(p, "  Function call interrupts\n");
97 	seq_printf(p, "%*s: ", prec, "TLB");
98 	for_each_online_cpu(j)
99 		seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
100 	seq_printf(p, "  TLB shootdowns\n");
101 #endif
102 #ifdef CONFIG_X86_THERMAL_VECTOR
103 	seq_printf(p, "%*s: ", prec, "TRM");
104 	for_each_online_cpu(j)
105 		seq_printf(p, "%10u ", irq_stats(j)->irq_thermal_count);
106 	seq_printf(p, "  Thermal event interrupts\n");
107 #endif
108 #ifdef CONFIG_X86_MCE_THRESHOLD
109 	seq_printf(p, "%*s: ", prec, "THR");
110 	for_each_online_cpu(j)
111 		seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
112 	seq_printf(p, "  Threshold APIC interrupts\n");
113 #endif
114 #ifdef CONFIG_X86_MCE
115 	seq_printf(p, "%*s: ", prec, "MCE");
116 	for_each_online_cpu(j)
117 		seq_printf(p, "%10u ", per_cpu(mce_exception_count, j));
118 	seq_printf(p, "  Machine check exceptions\n");
119 	seq_printf(p, "%*s: ", prec, "MCP");
120 	for_each_online_cpu(j)
121 		seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
122 	seq_printf(p, "  Machine check polls\n");
123 #endif
124 	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
125 #if defined(CONFIG_X86_IO_APIC)
126 	seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
127 #endif
128 	return 0;
129 }
130 
131 /*
132  * /proc/stat helpers
133  */
arch_irq_stat_cpu(unsigned int cpu)134 u64 arch_irq_stat_cpu(unsigned int cpu)
135 {
136 	u64 sum = irq_stats(cpu)->__nmi_count;
137 
138 #ifdef CONFIG_X86_LOCAL_APIC
139 	sum += irq_stats(cpu)->apic_timer_irqs;
140 	sum += irq_stats(cpu)->irq_spurious_count;
141 	sum += irq_stats(cpu)->apic_perf_irqs;
142 	sum += irq_stats(cpu)->apic_irq_work_irqs;
143 	sum += irq_stats(cpu)->icr_read_retry_count;
144 #endif
145 	if (x86_platform_ipi_callback)
146 		sum += irq_stats(cpu)->x86_platform_ipis;
147 #ifdef CONFIG_SMP
148 	sum += irq_stats(cpu)->irq_resched_count;
149 	sum += irq_stats(cpu)->irq_call_count;
150 	sum += irq_stats(cpu)->irq_tlb_count;
151 #endif
152 #ifdef CONFIG_X86_THERMAL_VECTOR
153 	sum += irq_stats(cpu)->irq_thermal_count;
154 #endif
155 #ifdef CONFIG_X86_MCE_THRESHOLD
156 	sum += irq_stats(cpu)->irq_threshold_count;
157 #endif
158 #ifdef CONFIG_X86_MCE
159 	sum += per_cpu(mce_exception_count, cpu);
160 	sum += per_cpu(mce_poll_count, cpu);
161 #endif
162 	return sum;
163 }
164 
arch_irq_stat(void)165 u64 arch_irq_stat(void)
166 {
167 	u64 sum = atomic_read(&irq_err_count);
168 	return sum;
169 }
170 
171 
172 /*
173  * do_IRQ handles all normal device IRQ's (the special
174  * SMP cross-CPU interrupts have their own specific
175  * handlers).
176  */
do_IRQ(struct pt_regs * regs)177 unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
178 {
179 	struct pt_regs *old_regs = set_irq_regs(regs);
180 
181 	/* high bit used in ret_from_ code  */
182 	unsigned vector = ~regs->orig_ax;
183 	unsigned irq;
184 
185 	irq_enter();
186 	exit_idle();
187 
188 	irq = __this_cpu_read(vector_irq[vector]);
189 
190 	if (!handle_irq(irq, regs)) {
191 		ack_APIC_irq();
192 
193 		if (printk_ratelimit())
194 			pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n",
195 				__func__, smp_processor_id(), vector, irq);
196 	}
197 
198 	irq_exit();
199 
200 	set_irq_regs(old_regs);
201 	return 1;
202 }
203 
204 /*
205  * Handler for X86_PLATFORM_IPI_VECTOR.
206  */
smp_x86_platform_ipi(struct pt_regs * regs)207 void smp_x86_platform_ipi(struct pt_regs *regs)
208 {
209 	struct pt_regs *old_regs = set_irq_regs(regs);
210 
211 	ack_APIC_irq();
212 
213 	irq_enter();
214 
215 	exit_idle();
216 
217 	inc_irq_stat(x86_platform_ipis);
218 
219 	if (x86_platform_ipi_callback)
220 		x86_platform_ipi_callback();
221 
222 	irq_exit();
223 
224 	set_irq_regs(old_regs);
225 }
226 
227 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
228 
229 #ifdef CONFIG_HOTPLUG_CPU
230 /* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
fixup_irqs(void)231 void fixup_irqs(void)
232 {
233 	unsigned int irq, vector;
234 	static int warned;
235 	struct irq_desc *desc;
236 	struct irq_data *data;
237 	struct irq_chip *chip;
238 
239 	for_each_irq_desc(irq, desc) {
240 		int break_affinity = 0;
241 		int set_affinity = 1;
242 		const struct cpumask *affinity;
243 
244 		if (!desc)
245 			continue;
246 		if (irq == 2)
247 			continue;
248 
249 		/* interrupt's are disabled at this point */
250 		raw_spin_lock(&desc->lock);
251 
252 		data = irq_desc_get_irq_data(desc);
253 		affinity = data->affinity;
254 		if (!irq_has_action(irq) || irqd_is_per_cpu(data) ||
255 		    cpumask_subset(affinity, cpu_online_mask)) {
256 			raw_spin_unlock(&desc->lock);
257 			continue;
258 		}
259 
260 		/*
261 		 * Complete the irq move. This cpu is going down and for
262 		 * non intr-remapping case, we can't wait till this interrupt
263 		 * arrives at this cpu before completing the irq move.
264 		 */
265 		irq_force_complete_move(irq);
266 
267 		if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
268 			break_affinity = 1;
269 			affinity = cpu_all_mask;
270 		}
271 
272 		chip = irq_data_get_irq_chip(data);
273 		if (!irqd_can_move_in_process_context(data) && chip->irq_mask)
274 			chip->irq_mask(data);
275 
276 		if (chip->irq_set_affinity)
277 			chip->irq_set_affinity(data, affinity, true);
278 		else if (!(warned++))
279 			set_affinity = 0;
280 
281 		/*
282 		 * We unmask if the irq was not marked masked by the
283 		 * core code. That respects the lazy irq disable
284 		 * behaviour.
285 		 */
286 		if (!irqd_can_move_in_process_context(data) &&
287 		    !irqd_irq_masked(data) && chip->irq_unmask)
288 			chip->irq_unmask(data);
289 
290 		raw_spin_unlock(&desc->lock);
291 
292 		if (break_affinity && set_affinity)
293 			printk("Broke affinity for irq %i\n", irq);
294 		else if (!set_affinity)
295 			printk("Cannot set affinity for irq %i\n", irq);
296 	}
297 
298 	/*
299 	 * We can remove mdelay() and then send spuriuous interrupts to
300 	 * new cpu targets for all the irqs that were handled previously by
301 	 * this cpu. While it works, I have seen spurious interrupt messages
302 	 * (nothing wrong but still...).
303 	 *
304 	 * So for now, retain mdelay(1) and check the IRR and then send those
305 	 * interrupts to new targets as this cpu is already offlined...
306 	 */
307 	mdelay(1);
308 
309 	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
310 		unsigned int irr;
311 
312 		if (__this_cpu_read(vector_irq[vector]) < 0)
313 			continue;
314 
315 		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
316 		if (irr  & (1 << (vector % 32))) {
317 			irq = __this_cpu_read(vector_irq[vector]);
318 
319 			desc = irq_to_desc(irq);
320 			data = irq_desc_get_irq_data(desc);
321 			chip = irq_data_get_irq_chip(data);
322 			raw_spin_lock(&desc->lock);
323 			if (chip->irq_retrigger)
324 				chip->irq_retrigger(data);
325 			raw_spin_unlock(&desc->lock);
326 		}
327 	}
328 }
329 #endif
330