xref: /openbmc/linux/arch/ia64/kernel/irq_ia64.c (revision a44e4f3a) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/arch/ia64/kernel/irq_ia64.c
4  *
5  * Copyright (C) 1998-2001 Hewlett-Packard Co
6  *	Stephane Eranian <eranian@hpl.hp.com>
7  *	David Mosberger-Tang <davidm@hpl.hp.com>
8  *
9  *  6/10/99: Updated to bring in sync with x86 version to facilitate
10  *	     support for SMP and different interrupt controllers.
11  *
12  * 09/15/00 Goutham Rao <goutham.rao@intel.com> Implemented pci_irq_to_vector
13  *                      PCI to vector allocation routine.
14  * 04/14/2004 Ashok Raj <ashok.raj@intel.com>
15  *						Added CPU Hotplug handling for IPF.
16  */
17 
18 #include <linux/module.h>
19 
20 #include <linux/jiffies.h>
21 #include <linux/errno.h>
22 #include <linux/init.h>
23 #include <linux/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/ptrace.h>
27 #include <linux/signal.h>
28 #include <linux/smp.h>
29 #include <linux/threads.h>
30 #include <linux/bitops.h>
31 #include <linux/irq.h>
32 #include <linux/ratelimit.h>
33 #include <linux/acpi.h>
34 #include <linux/sched.h>
35 
36 #include <asm/delay.h>
37 #include <asm/intrinsics.h>
38 #include <asm/io.h>
39 #include <asm/hw_irq.h>
40 #include <asm/pgtable.h>
41 #include <asm/tlbflush.h>
42 
43 #ifdef CONFIG_PERFMON
44 # include <asm/perfmon.h>
45 #endif
46 
47 #define IRQ_DEBUG	0
48 
49 #define IRQ_VECTOR_UNASSIGNED	(0)
50 
51 #define IRQ_UNUSED		(0)
52 #define IRQ_USED		(1)
53 #define IRQ_RSVD		(2)
54 
55 int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
56 int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
57 
58 /* default base addr of IPI table */
59 void __iomem *ipi_base_addr = ((void __iomem *)
60 			       (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
61 
62 static cpumask_t vector_allocation_domain(int cpu);
63 
64 /*
65  * Legacy IRQ to IA-64 vector translation table.
66  */
67 __u8 isa_irq_to_vector_map[16] = {
68 	/* 8259 IRQ translation, first 16 entries */
69 	0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
70 	0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
71 };
72 EXPORT_SYMBOL(isa_irq_to_vector_map);
73 
74 DEFINE_SPINLOCK(vector_lock);
75 
76 struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
77 	[0 ... NR_IRQS - 1] = {
78 		.vector = IRQ_VECTOR_UNASSIGNED,
79 		.domain = CPU_MASK_NONE
80 	}
81 };
82 
83 DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
84 	[0 ... IA64_NUM_VECTORS - 1] = -1
85 };
86 
87 static cpumask_t vector_table[IA64_NUM_VECTORS] = {
88 	[0 ... IA64_NUM_VECTORS - 1] = CPU_MASK_NONE
89 };
90 
91 static int irq_status[NR_IRQS] = {
92 	[0 ... NR_IRQS -1] = IRQ_UNUSED
93 };
94 
95 static inline int find_unassigned_irq(void)
96 {
97 	int irq;
98 
99 	for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
100 		if (irq_status[irq] == IRQ_UNUSED)
101 			return irq;
102 	return -ENOSPC;
103 }
104 
105 static inline int find_unassigned_vector(cpumask_t domain)
106 {
107 	cpumask_t mask;
108 	int pos, vector;
109 
110 	cpumask_and(&mask, &domain, cpu_online_mask);
111 	if (cpumask_empty(&mask))
112 		return -EINVAL;
113 
114 	for (pos = 0; pos < IA64_NUM_DEVICE_VECTORS; pos++) {
115 		vector = IA64_FIRST_DEVICE_VECTOR + pos;
116 		cpumask_and(&mask, &domain, &vector_table[vector]);
117 		if (!cpumask_empty(&mask))
118 			continue;
119 		return vector;
120 	}
121 	return -ENOSPC;
122 }
123 
124 static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
125 {
126 	cpumask_t mask;
127 	int cpu;
128 	struct irq_cfg *cfg = &irq_cfg[irq];
129 
130 	BUG_ON((unsigned)irq >= NR_IRQS);
131 	BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);
132 
133 	cpumask_and(&mask, &domain, cpu_online_mask);
134 	if (cpumask_empty(&mask))
135 		return -EINVAL;
136 	if ((cfg->vector == vector) && cpumask_equal(&cfg->domain, &domain))
137 		return 0;
138 	if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
139 		return -EBUSY;
140 	for_each_cpu(cpu, &mask)
141 		per_cpu(vector_irq, cpu)[vector] = irq;
142 	cfg->vector = vector;
143 	cfg->domain = domain;
144 	irq_status[irq] = IRQ_USED;
145 	cpumask_or(&vector_table[vector], &vector_table[vector], &domain);
146 	return 0;
147 }
148 
149 int bind_irq_vector(int irq, int vector, cpumask_t domain)
150 {
151 	unsigned long flags;
152 	int ret;
153 
154 	spin_lock_irqsave(&vector_lock, flags);
155 	ret = __bind_irq_vector(irq, vector, domain);
156 	spin_unlock_irqrestore(&vector_lock, flags);
157 	return ret;
158 }
159 
160 static void __clear_irq_vector(int irq)
161 {
162 	int vector, cpu;
163 	cpumask_t domain;
164 	struct irq_cfg *cfg = &irq_cfg[irq];
165 
166 	BUG_ON((unsigned)irq >= NR_IRQS);
167 	BUG_ON(cfg->vector == IRQ_VECTOR_UNASSIGNED);
168 	vector = cfg->vector;
169 	domain = cfg->domain;
170 	for_each_cpu_and(cpu, &cfg->domain, cpu_online_mask)
171 		per_cpu(vector_irq, cpu)[vector] = -1;
172 	cfg->vector = IRQ_VECTOR_UNASSIGNED;
173 	cfg->domain = CPU_MASK_NONE;
174 	irq_status[irq] = IRQ_UNUSED;
175 	cpumask_andnot(&vector_table[vector], &vector_table[vector], &domain);
176 }
177 
178 static void clear_irq_vector(int irq)
179 {
180 	unsigned long flags;
181 
182 	spin_lock_irqsave(&vector_lock, flags);
183 	__clear_irq_vector(irq);
184 	spin_unlock_irqrestore(&vector_lock, flags);
185 }
186 
187 int
188 ia64_native_assign_irq_vector (int irq)
189 {
190 	unsigned long flags;
191 	int vector, cpu;
192 	cpumask_t domain = CPU_MASK_NONE;
193 
194 	vector = -ENOSPC;
195 
196 	spin_lock_irqsave(&vector_lock, flags);
197 	for_each_online_cpu(cpu) {
198 		domain = vector_allocation_domain(cpu);
199 		vector = find_unassigned_vector(domain);
200 		if (vector >= 0)
201 			break;
202 	}
203 	if (vector < 0)
204 		goto out;
205 	if (irq == AUTO_ASSIGN)
206 		irq = vector;
207 	BUG_ON(__bind_irq_vector(irq, vector, domain));
208  out:
209 	spin_unlock_irqrestore(&vector_lock, flags);
210 	return vector;
211 }
212 
213 void
214 ia64_native_free_irq_vector (int vector)
215 {
216 	if (vector < IA64_FIRST_DEVICE_VECTOR ||
217 	    vector > IA64_LAST_DEVICE_VECTOR)
218 		return;
219 	clear_irq_vector(vector);
220 }
221 
222 int
223 reserve_irq_vector (int vector)
224 {
225 	if (vector < IA64_FIRST_DEVICE_VECTOR ||
226 	    vector > IA64_LAST_DEVICE_VECTOR)
227 		return -EINVAL;
228 	return !!bind_irq_vector(vector, vector, CPU_MASK_ALL);
229 }
230 
231 /*
232  * Initialize vector_irq on a new cpu. This function must be called
233  * with vector_lock held.
234  */
235 void __setup_vector_irq(int cpu)
236 {
237 	int irq, vector;
238 
239 	/* Clear vector_irq */
240 	for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
241 		per_cpu(vector_irq, cpu)[vector] = -1;
242 	/* Mark the inuse vectors */
243 	for (irq = 0; irq < NR_IRQS; ++irq) {
244 		if (!cpumask_test_cpu(cpu, &irq_cfg[irq].domain))
245 			continue;
246 		vector = irq_to_vector(irq);
247 		per_cpu(vector_irq, cpu)[vector] = irq;
248 	}
249 }
250 
251 #ifdef CONFIG_SMP
252 
253 static enum vector_domain_type {
254 	VECTOR_DOMAIN_NONE,
255 	VECTOR_DOMAIN_PERCPU
256 } vector_domain_type = VECTOR_DOMAIN_NONE;
257 
258 static cpumask_t vector_allocation_domain(int cpu)
259 {
260 	if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
261 		return *cpumask_of(cpu);
262 	return CPU_MASK_ALL;
263 }
264 
265 static int __irq_prepare_move(int irq, int cpu)
266 {
267 	struct irq_cfg *cfg = &irq_cfg[irq];
268 	int vector;
269 	cpumask_t domain;
270 
271 	if (cfg->move_in_progress || cfg->move_cleanup_count)
272 		return -EBUSY;
273 	if (cfg->vector == IRQ_VECTOR_UNASSIGNED || !cpu_online(cpu))
274 		return -EINVAL;
275 	if (cpumask_test_cpu(cpu, &cfg->domain))
276 		return 0;
277 	domain = vector_allocation_domain(cpu);
278 	vector = find_unassigned_vector(domain);
279 	if (vector < 0)
280 		return -ENOSPC;
281 	cfg->move_in_progress = 1;
282 	cfg->old_domain = cfg->domain;
283 	cfg->vector = IRQ_VECTOR_UNASSIGNED;
284 	cfg->domain = CPU_MASK_NONE;
285 	BUG_ON(__bind_irq_vector(irq, vector, domain));
286 	return 0;
287 }
288 
289 int irq_prepare_move(int irq, int cpu)
290 {
291 	unsigned long flags;
292 	int ret;
293 
294 	spin_lock_irqsave(&vector_lock, flags);
295 	ret = __irq_prepare_move(irq, cpu);
296 	spin_unlock_irqrestore(&vector_lock, flags);
297 	return ret;
298 }
299 
300 void irq_complete_move(unsigned irq)
301 {
302 	struct irq_cfg *cfg = &irq_cfg[irq];
303 	cpumask_t cleanup_mask;
304 	int i;
305 
306 	if (likely(!cfg->move_in_progress))
307 		return;
308 
309 	if (unlikely(cpumask_test_cpu(smp_processor_id(), &cfg->old_domain)))
310 		return;
311 
312 	cpumask_and(&cleanup_mask, &cfg->old_domain, cpu_online_mask);
313 	cfg->move_cleanup_count = cpumask_weight(&cleanup_mask);
314 	for_each_cpu(i, &cleanup_mask)
315 		ia64_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0);
316 	cfg->move_in_progress = 0;
317 }
318 
319 static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id)
320 {
321 	int me = smp_processor_id();
322 	ia64_vector vector;
323 	unsigned long flags;
324 
325 	for (vector = IA64_FIRST_DEVICE_VECTOR;
326 	     vector < IA64_LAST_DEVICE_VECTOR; vector++) {
327 		int irq;
328 		struct irq_desc *desc;
329 		struct irq_cfg *cfg;
330 		irq = __this_cpu_read(vector_irq[vector]);
331 		if (irq < 0)
332 			continue;
333 
334 		desc = irq_to_desc(irq);
335 		cfg = irq_cfg + irq;
336 		raw_spin_lock(&desc->lock);
337 		if (!cfg->move_cleanup_count)
338 			goto unlock;
339 
340 		if (!cpumask_test_cpu(me, &cfg->old_domain))
341 			goto unlock;
342 
343 		spin_lock_irqsave(&vector_lock, flags);
344 		__this_cpu_write(vector_irq[vector], -1);
345 		cpumask_clear_cpu(me, &vector_table[vector]);
346 		spin_unlock_irqrestore(&vector_lock, flags);
347 		cfg->move_cleanup_count--;
348 	unlock:
349 		raw_spin_unlock(&desc->lock);
350 	}
351 	return IRQ_HANDLED;
352 }
353 
354 static struct irqaction irq_move_irqaction = {
355 	.handler =	smp_irq_move_cleanup_interrupt,
356 	.name =		"irq_move"
357 };
358 
359 static int __init parse_vector_domain(char *arg)
360 {
361 	if (!arg)
362 		return -EINVAL;
363 	if (!strcmp(arg, "percpu")) {
364 		vector_domain_type = VECTOR_DOMAIN_PERCPU;
365 		no_int_routing = 1;
366 	}
367 	return 0;
368 }
369 early_param("vector", parse_vector_domain);
370 #else
371 static cpumask_t vector_allocation_domain(int cpu)
372 {
373 	return CPU_MASK_ALL;
374 }
375 #endif
376 
377 
378 void destroy_and_reserve_irq(unsigned int irq)
379 {
380 	unsigned long flags;
381 
382 	irq_init_desc(irq);
383 	spin_lock_irqsave(&vector_lock, flags);
384 	__clear_irq_vector(irq);
385 	irq_status[irq] = IRQ_RSVD;
386 	spin_unlock_irqrestore(&vector_lock, flags);
387 }
388 
389 /*
390  * Dynamic irq allocate and deallocation for MSI
391  */
392 int create_irq(void)
393 {
394 	unsigned long flags;
395 	int irq, vector, cpu;
396 	cpumask_t domain = CPU_MASK_NONE;
397 
398 	irq = vector = -ENOSPC;
399 	spin_lock_irqsave(&vector_lock, flags);
400 	for_each_online_cpu(cpu) {
401 		domain = vector_allocation_domain(cpu);
402 		vector = find_unassigned_vector(domain);
403 		if (vector >= 0)
404 			break;
405 	}
406 	if (vector < 0)
407 		goto out;
408 	irq = find_unassigned_irq();
409 	if (irq < 0)
410 		goto out;
411 	BUG_ON(__bind_irq_vector(irq, vector, domain));
412  out:
413 	spin_unlock_irqrestore(&vector_lock, flags);
414 	if (irq >= 0)
415 		irq_init_desc(irq);
416 	return irq;
417 }
418 
419 void destroy_irq(unsigned int irq)
420 {
421 	irq_init_desc(irq);
422 	clear_irq_vector(irq);
423 }
424 
425 #ifdef CONFIG_SMP
426 #	define IS_RESCHEDULE(vec)	(vec == IA64_IPI_RESCHEDULE)
427 #	define IS_LOCAL_TLB_FLUSH(vec)	(vec == IA64_IPI_LOCAL_TLB_FLUSH)
428 #else
429 #	define IS_RESCHEDULE(vec)	(0)
430 #	define IS_LOCAL_TLB_FLUSH(vec)	(0)
431 #endif
432 /*
433  * That's where the IVT branches when we get an external
434  * interrupt. This branches to the correct hardware IRQ handler via
435  * function ptr.
436  */
437 void
438 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
439 {
440 	struct pt_regs *old_regs = set_irq_regs(regs);
441 	unsigned long saved_tpr;
442 
443 #if IRQ_DEBUG
444 	{
445 		unsigned long bsp, sp;
446 
447 		/*
448 		 * Note: if the interrupt happened while executing in
449 		 * the context switch routine (ia64_switch_to), we may
450 		 * get a spurious stack overflow here.  This is
451 		 * because the register and the memory stack are not
452 		 * switched atomically.
453 		 */
454 		bsp = ia64_getreg(_IA64_REG_AR_BSP);
455 		sp = ia64_getreg(_IA64_REG_SP);
456 
457 		if ((sp - bsp) < 1024) {
458 			static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
459 
460 			if (__ratelimit(&ratelimit)) {
461 				printk("ia64_handle_irq: DANGER: less than "
462 				       "1KB of free stack space!!\n"
463 				       "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
464 			}
465 		}
466 	}
467 #endif /* IRQ_DEBUG */
468 
469 	/*
470 	 * Always set TPR to limit maximum interrupt nesting depth to
471 	 * 16 (without this, it would be ~240, which could easily lead
472 	 * to kernel stack overflows).
473 	 */
474 	irq_enter();
475 	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
476 	ia64_srlz_d();
477 	while (vector != IA64_SPURIOUS_INT_VECTOR) {
478 		int irq = local_vector_to_irq(vector);
479 
480 		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
481 			smp_local_flush_tlb();
482 			kstat_incr_irq_this_cpu(irq);
483 		} else if (unlikely(IS_RESCHEDULE(vector))) {
484 			scheduler_ipi();
485 			kstat_incr_irq_this_cpu(irq);
486 		} else {
487 			ia64_setreg(_IA64_REG_CR_TPR, vector);
488 			ia64_srlz_d();
489 
490 			if (unlikely(irq < 0)) {
491 				printk(KERN_ERR "%s: Unexpected interrupt "
492 				       "vector %d on CPU %d is not mapped "
493 				       "to any IRQ!\n", __func__, vector,
494 				       smp_processor_id());
495 			} else
496 				generic_handle_irq(irq);
497 
498 			/*
499 			 * Disable interrupts and send EOI:
500 			 */
501 			local_irq_disable();
502 			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
503 		}
504 		ia64_eoi();
505 		vector = ia64_get_ivr();
506 	}
507 	/*
508 	 * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
509 	 * handler needs to be able to wait for further keyboard interrupts, which can't
510 	 * come through until ia64_eoi() has been done.
511 	 */
512 	irq_exit();
513 	set_irq_regs(old_regs);
514 }
515 
516 #ifdef CONFIG_HOTPLUG_CPU
517 /*
518  * This function emulates a interrupt processing when a cpu is about to be
519  * brought down.
520  */
521 void ia64_process_pending_intr(void)
522 {
523 	ia64_vector vector;
524 	unsigned long saved_tpr;
525 	extern unsigned int vectors_in_migration[NR_IRQS];
526 
527 	vector = ia64_get_ivr();
528 
529 	irq_enter();
530 	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
531 	ia64_srlz_d();
532 
533 	 /*
534 	  * Perform normal interrupt style processing
535 	  */
536 	while (vector != IA64_SPURIOUS_INT_VECTOR) {
537 		int irq = local_vector_to_irq(vector);
538 
539 		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
540 			smp_local_flush_tlb();
541 			kstat_incr_irq_this_cpu(irq);
542 		} else if (unlikely(IS_RESCHEDULE(vector))) {
543 			kstat_incr_irq_this_cpu(irq);
544 		} else {
545 			struct pt_regs *old_regs = set_irq_regs(NULL);
546 
547 			ia64_setreg(_IA64_REG_CR_TPR, vector);
548 			ia64_srlz_d();
549 
550 			/*
551 			 * Now try calling normal ia64_handle_irq as it would have got called
552 			 * from a real intr handler. Try passing null for pt_regs, hopefully
553 			 * it will work. I hope it works!.
554 			 * Probably could shared code.
555 			 */
556 			if (unlikely(irq < 0)) {
557 				printk(KERN_ERR "%s: Unexpected interrupt "
558 				       "vector %d on CPU %d not being mapped "
559 				       "to any IRQ!!\n", __func__, vector,
560 				       smp_processor_id());
561 			} else {
562 				vectors_in_migration[irq]=0;
563 				generic_handle_irq(irq);
564 			}
565 			set_irq_regs(old_regs);
566 
567 			/*
568 			 * Disable interrupts and send EOI
569 			 */
570 			local_irq_disable();
571 			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
572 		}
573 		ia64_eoi();
574 		vector = ia64_get_ivr();
575 	}
576 	irq_exit();
577 }
578 #endif
579 
580 
581 #ifdef CONFIG_SMP
582 
583 static irqreturn_t dummy_handler (int irq, void *dev_id)
584 {
585 	BUG();
586 	return IRQ_NONE;
587 }
588 
589 static struct irqaction ipi_irqaction = {
590 	.handler =	handle_IPI,
591 	.name =		"IPI"
592 };
593 
594 /*
595  * KVM uses this interrupt to force a cpu out of guest mode
596  */
597 static struct irqaction resched_irqaction = {
598 	.handler =	dummy_handler,
599 	.name =		"resched"
600 };
601 
602 static struct irqaction tlb_irqaction = {
603 	.handler =	dummy_handler,
604 	.name =		"tlb_flush"
605 };
606 
607 #endif
608 
609 void
610 ia64_native_register_percpu_irq (ia64_vector vec, struct irqaction *action)
611 {
612 	unsigned int irq;
613 
614 	irq = vec;
615 	BUG_ON(bind_irq_vector(irq, vec, CPU_MASK_ALL));
616 	irq_set_status_flags(irq, IRQ_PER_CPU);
617 	irq_set_chip(irq, &irq_type_ia64_lsapic);
618 	if (action)
619 		setup_irq(irq, action);
620 	irq_set_handler(irq, handle_percpu_irq);
621 }
622 
623 void __init
624 ia64_native_register_ipi(void)
625 {
626 #ifdef CONFIG_SMP
627 	register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
628 	register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
629 	register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &tlb_irqaction);
630 #endif
631 }
632 
633 void __init
634 init_IRQ (void)
635 {
636 	acpi_boot_init();
637 	ia64_register_ipi();
638 	register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
639 #ifdef CONFIG_SMP
640 	if (vector_domain_type != VECTOR_DOMAIN_NONE)
641 		register_percpu_irq(IA64_IRQ_MOVE_VECTOR, &irq_move_irqaction);
642 #endif
643 #ifdef CONFIG_PERFMON
644 	pfm_init_percpu();
645 #endif
646 }
647 
648 void
649 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
650 {
651 	void __iomem *ipi_addr;
652 	unsigned long ipi_data;
653 	unsigned long phys_cpu_id;
654 
655 	phys_cpu_id = cpu_physical_id(cpu);
656 
657 	/*
658 	 * cpu number is in 8bit ID and 8bit EID
659 	 */
660 
661 	ipi_data = (delivery_mode << 8) | (vector & 0xff);
662 	ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
663 
664 	writeq(ipi_data, ipi_addr);
665 }
666