xref: /openbmc/linux/arch/ia64/kernel/irq_ia64.c (revision 3a35093a) 
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 #include <linux/pgtable.h>
20 
21 #include <linux/jiffies.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/interrupt.h>
25 #include <linux/ioport.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/ptrace.h>
28 #include <linux/signal.h>
29 #include <linux/smp.h>
30 #include <linux/threads.h>
31 #include <linux/bitops.h>
32 #include <linux/irq.h>
33 #include <linux/ratelimit.h>
34 #include <linux/acpi.h>
35 #include <linux/sched.h>
36 
37 #include <asm/delay.h>
38 #include <asm/intrinsics.h>
39 #include <asm/io.h>
40 #include <asm/hw_irq.h>
41 #include <asm/tlbflush.h>
42 
43 #define IRQ_DEBUG	0
44 
45 #define IRQ_VECTOR_UNASSIGNED	(0)
46 
47 #define IRQ_UNUSED		(0)
48 #define IRQ_USED		(1)
49 #define IRQ_RSVD		(2)
50 
51 int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
52 int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
53 
54 /* default base addr of IPI table */
55 void __iomem *ipi_base_addr = ((void __iomem *)
56 			       (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
57 
58 static cpumask_t vector_allocation_domain(int cpu);
59 
60 /*
61  * Legacy IRQ to IA-64 vector translation table.
62  */
63 __u8 isa_irq_to_vector_map[16] = {
64 	/* 8259 IRQ translation, first 16 entries */
65 	0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
66 	0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
67 };
68 EXPORT_SYMBOL(isa_irq_to_vector_map);
69 
70 DEFINE_SPINLOCK(vector_lock);
71 
72 struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
73 	[0 ... NR_IRQS - 1] = {
74 		.vector = IRQ_VECTOR_UNASSIGNED,
75 		.domain = CPU_MASK_NONE
76 	}
77 };
78 
79 DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
80 	[0 ... IA64_NUM_VECTORS - 1] = -1
81 };
82 
83 static cpumask_t vector_table[IA64_NUM_VECTORS] = {
84 	[0 ... IA64_NUM_VECTORS - 1] = CPU_MASK_NONE
85 };
86 
87 static int irq_status[NR_IRQS] = {
88 	[0 ... NR_IRQS -1] = IRQ_UNUSED
89 };
90 
91 static inline int find_unassigned_irq(void)
92 {
93 	int irq;
94 
95 	for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
96 		if (irq_status[irq] == IRQ_UNUSED)
97 			return irq;
98 	return -ENOSPC;
99 }
100 
101 static inline int find_unassigned_vector(cpumask_t domain)
102 {
103 	cpumask_t mask;
104 	int pos, vector;
105 
106 	cpumask_and(&mask, &domain, cpu_online_mask);
107 	if (cpumask_empty(&mask))
108 		return -EINVAL;
109 
110 	for (pos = 0; pos < IA64_NUM_DEVICE_VECTORS; pos++) {
111 		vector = IA64_FIRST_DEVICE_VECTOR + pos;
112 		cpumask_and(&mask, &domain, &vector_table[vector]);
113 		if (!cpumask_empty(&mask))
114 			continue;
115 		return vector;
116 	}
117 	return -ENOSPC;
118 }
119 
120 static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
121 {
122 	cpumask_t mask;
123 	int cpu;
124 	struct irq_cfg *cfg = &irq_cfg[irq];
125 
126 	BUG_ON((unsigned)irq >= NR_IRQS);
127 	BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);
128 
129 	cpumask_and(&mask, &domain, cpu_online_mask);
130 	if (cpumask_empty(&mask))
131 		return -EINVAL;
132 	if ((cfg->vector == vector) && cpumask_equal(&cfg->domain, &domain))
133 		return 0;
134 	if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
135 		return -EBUSY;
136 	for_each_cpu(cpu, &mask)
137 		per_cpu(vector_irq, cpu)[vector] = irq;
138 	cfg->vector = vector;
139 	cfg->domain = domain;
140 	irq_status[irq] = IRQ_USED;
141 	cpumask_or(&vector_table[vector], &vector_table[vector], &domain);
142 	return 0;
143 }
144 
145 int bind_irq_vector(int irq, int vector, cpumask_t domain)
146 {
147 	unsigned long flags;
148 	int ret;
149 
150 	spin_lock_irqsave(&vector_lock, flags);
151 	ret = __bind_irq_vector(irq, vector, domain);
152 	spin_unlock_irqrestore(&vector_lock, flags);
153 	return ret;
154 }
155 
156 static void __clear_irq_vector(int irq)
157 {
158 	int vector, cpu;
159 	cpumask_t domain;
160 	struct irq_cfg *cfg = &irq_cfg[irq];
161 
162 	BUG_ON((unsigned)irq >= NR_IRQS);
163 	BUG_ON(cfg->vector == IRQ_VECTOR_UNASSIGNED);
164 	vector = cfg->vector;
165 	domain = cfg->domain;
166 	for_each_cpu_and(cpu, &cfg->domain, cpu_online_mask)
167 		per_cpu(vector_irq, cpu)[vector] = -1;
168 	cfg->vector = IRQ_VECTOR_UNASSIGNED;
169 	cfg->domain = CPU_MASK_NONE;
170 	irq_status[irq] = IRQ_UNUSED;
171 	cpumask_andnot(&vector_table[vector], &vector_table[vector], &domain);
172 }
173 
174 static void clear_irq_vector(int irq)
175 {
176 	unsigned long flags;
177 
178 	spin_lock_irqsave(&vector_lock, flags);
179 	__clear_irq_vector(irq);
180 	spin_unlock_irqrestore(&vector_lock, flags);
181 }
182 
183 int
184 ia64_native_assign_irq_vector (int irq)
185 {
186 	unsigned long flags;
187 	int vector, cpu;
188 	cpumask_t domain = CPU_MASK_NONE;
189 
190 	vector = -ENOSPC;
191 
192 	spin_lock_irqsave(&vector_lock, flags);
193 	for_each_online_cpu(cpu) {
194 		domain = vector_allocation_domain(cpu);
195 		vector = find_unassigned_vector(domain);
196 		if (vector >= 0)
197 			break;
198 	}
199 	if (vector < 0)
200 		goto out;
201 	if (irq == AUTO_ASSIGN)
202 		irq = vector;
203 	BUG_ON(__bind_irq_vector(irq, vector, domain));
204  out:
205 	spin_unlock_irqrestore(&vector_lock, flags);
206 	return vector;
207 }
208 
209 void
210 ia64_native_free_irq_vector (int vector)
211 {
212 	if (vector < IA64_FIRST_DEVICE_VECTOR ||
213 	    vector > IA64_LAST_DEVICE_VECTOR)
214 		return;
215 	clear_irq_vector(vector);
216 }
217 
218 int
219 reserve_irq_vector (int vector)
220 {
221 	if (vector < IA64_FIRST_DEVICE_VECTOR ||
222 	    vector > IA64_LAST_DEVICE_VECTOR)
223 		return -EINVAL;
224 	return !!bind_irq_vector(vector, vector, CPU_MASK_ALL);
225 }
226 
227 /*
228  * Initialize vector_irq on a new cpu. This function must be called
229  * with vector_lock held.
230  */
231 void __setup_vector_irq(int cpu)
232 {
233 	int irq, vector;
234 
235 	/* Clear vector_irq */
236 	for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
237 		per_cpu(vector_irq, cpu)[vector] = -1;
238 	/* Mark the inuse vectors */
239 	for (irq = 0; irq < NR_IRQS; ++irq) {
240 		if (!cpumask_test_cpu(cpu, &irq_cfg[irq].domain))
241 			continue;
242 		vector = irq_to_vector(irq);
243 		per_cpu(vector_irq, cpu)[vector] = irq;
244 	}
245 }
246 
247 #ifdef CONFIG_SMP
248 
249 static enum vector_domain_type {
250 	VECTOR_DOMAIN_NONE,
251 	VECTOR_DOMAIN_PERCPU
252 } vector_domain_type = VECTOR_DOMAIN_NONE;
253 
254 static cpumask_t vector_allocation_domain(int cpu)
255 {
256 	if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
257 		return *cpumask_of(cpu);
258 	return CPU_MASK_ALL;
259 }
260 
261 static int __irq_prepare_move(int irq, int cpu)
262 {
263 	struct irq_cfg *cfg = &irq_cfg[irq];
264 	int vector;
265 	cpumask_t domain;
266 
267 	if (cfg->move_in_progress || cfg->move_cleanup_count)
268 		return -EBUSY;
269 	if (cfg->vector == IRQ_VECTOR_UNASSIGNED || !cpu_online(cpu))
270 		return -EINVAL;
271 	if (cpumask_test_cpu(cpu, &cfg->domain))
272 		return 0;
273 	domain = vector_allocation_domain(cpu);
274 	vector = find_unassigned_vector(domain);
275 	if (vector < 0)
276 		return -ENOSPC;
277 	cfg->move_in_progress = 1;
278 	cfg->old_domain = cfg->domain;
279 	cfg->vector = IRQ_VECTOR_UNASSIGNED;
280 	cfg->domain = CPU_MASK_NONE;
281 	BUG_ON(__bind_irq_vector(irq, vector, domain));
282 	return 0;
283 }
284 
285 int irq_prepare_move(int irq, int cpu)
286 {
287 	unsigned long flags;
288 	int ret;
289 
290 	spin_lock_irqsave(&vector_lock, flags);
291 	ret = __irq_prepare_move(irq, cpu);
292 	spin_unlock_irqrestore(&vector_lock, flags);
293 	return ret;
294 }
295 
296 void irq_complete_move(unsigned irq)
297 {
298 	struct irq_cfg *cfg = &irq_cfg[irq];
299 	cpumask_t cleanup_mask;
300 	int i;
301 
302 	if (likely(!cfg->move_in_progress))
303 		return;
304 
305 	if (unlikely(cpumask_test_cpu(smp_processor_id(), &cfg->old_domain)))
306 		return;
307 
308 	cpumask_and(&cleanup_mask, &cfg->old_domain, cpu_online_mask);
309 	cfg->move_cleanup_count = cpumask_weight(&cleanup_mask);
310 	for_each_cpu(i, &cleanup_mask)
311 		ia64_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0);
312 	cfg->move_in_progress = 0;
313 }
314 
315 static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id)
316 {
317 	int me = smp_processor_id();
318 	ia64_vector vector;
319 	unsigned long flags;
320 
321 	for (vector = IA64_FIRST_DEVICE_VECTOR;
322 	     vector < IA64_LAST_DEVICE_VECTOR; vector++) {
323 		int irq;
324 		struct irq_desc *desc;
325 		struct irq_cfg *cfg;
326 		irq = __this_cpu_read(vector_irq[vector]);
327 		if (irq < 0)
328 			continue;
329 
330 		desc = irq_to_desc(irq);
331 		cfg = irq_cfg + irq;
332 		raw_spin_lock(&desc->lock);
333 		if (!cfg->move_cleanup_count)
334 			goto unlock;
335 
336 		if (!cpumask_test_cpu(me, &cfg->old_domain))
337 			goto unlock;
338 
339 		spin_lock_irqsave(&vector_lock, flags);
340 		__this_cpu_write(vector_irq[vector], -1);
341 		cpumask_clear_cpu(me, &vector_table[vector]);
342 		spin_unlock_irqrestore(&vector_lock, flags);
343 		cfg->move_cleanup_count--;
344 	unlock:
345 		raw_spin_unlock(&desc->lock);
346 	}
347 	return IRQ_HANDLED;
348 }
349 
350 static int __init parse_vector_domain(char *arg)
351 {
352 	if (!arg)
353 		return -EINVAL;
354 	if (!strcmp(arg, "percpu")) {
355 		vector_domain_type = VECTOR_DOMAIN_PERCPU;
356 		no_int_routing = 1;
357 	}
358 	return 0;
359 }
360 early_param("vector", parse_vector_domain);
361 #else
362 static cpumask_t vector_allocation_domain(int cpu)
363 {
364 	return CPU_MASK_ALL;
365 }
366 #endif
367 
368 
369 void destroy_and_reserve_irq(unsigned int irq)
370 {
371 	unsigned long flags;
372 
373 	irq_init_desc(irq);
374 	spin_lock_irqsave(&vector_lock, flags);
375 	__clear_irq_vector(irq);
376 	irq_status[irq] = IRQ_RSVD;
377 	spin_unlock_irqrestore(&vector_lock, flags);
378 }
379 
380 /*
381  * Dynamic irq allocate and deallocation for MSI
382  */
383 int create_irq(void)
384 {
385 	unsigned long flags;
386 	int irq, vector, cpu;
387 	cpumask_t domain = CPU_MASK_NONE;
388 
389 	irq = vector = -ENOSPC;
390 	spin_lock_irqsave(&vector_lock, flags);
391 	for_each_online_cpu(cpu) {
392 		domain = vector_allocation_domain(cpu);
393 		vector = find_unassigned_vector(domain);
394 		if (vector >= 0)
395 			break;
396 	}
397 	if (vector < 0)
398 		goto out;
399 	irq = find_unassigned_irq();
400 	if (irq < 0)
401 		goto out;
402 	BUG_ON(__bind_irq_vector(irq, vector, domain));
403  out:
404 	spin_unlock_irqrestore(&vector_lock, flags);
405 	if (irq >= 0)
406 		irq_init_desc(irq);
407 	return irq;
408 }
409 
410 void destroy_irq(unsigned int irq)
411 {
412 	irq_init_desc(irq);
413 	clear_irq_vector(irq);
414 }
415 
416 #ifdef CONFIG_SMP
417 #	define IS_RESCHEDULE(vec)	(vec == IA64_IPI_RESCHEDULE)
418 #	define IS_LOCAL_TLB_FLUSH(vec)	(vec == IA64_IPI_LOCAL_TLB_FLUSH)
419 #else
420 #	define IS_RESCHEDULE(vec)	(0)
421 #	define IS_LOCAL_TLB_FLUSH(vec)	(0)
422 #endif
423 /*
424  * That's where the IVT branches when we get an external
425  * interrupt. This branches to the correct hardware IRQ handler via
426  * function ptr.
427  */
428 void
429 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
430 {
431 	struct pt_regs *old_regs = set_irq_regs(regs);
432 	unsigned long saved_tpr;
433 
434 #if IRQ_DEBUG
435 	{
436 		unsigned long bsp, sp;
437 
438 		/*
439 		 * Note: if the interrupt happened while executing in
440 		 * the context switch routine (ia64_switch_to), we may
441 		 * get a spurious stack overflow here.  This is
442 		 * because the register and the memory stack are not
443 		 * switched atomically.
444 		 */
445 		bsp = ia64_getreg(_IA64_REG_AR_BSP);
446 		sp = ia64_getreg(_IA64_REG_SP);
447 
448 		if ((sp - bsp) < 1024) {
449 			static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
450 
451 			if (__ratelimit(&ratelimit)) {
452 				printk("ia64_handle_irq: DANGER: less than "
453 				       "1KB of free stack space!!\n"
454 				       "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
455 			}
456 		}
457 	}
458 #endif /* IRQ_DEBUG */
459 
460 	/*
461 	 * Always set TPR to limit maximum interrupt nesting depth to
462 	 * 16 (without this, it would be ~240, which could easily lead
463 	 * to kernel stack overflows).
464 	 */
465 	irq_enter();
466 	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
467 	ia64_srlz_d();
468 	while (vector != IA64_SPURIOUS_INT_VECTOR) {
469 		int irq = local_vector_to_irq(vector);
470 
471 		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
472 			smp_local_flush_tlb();
473 			kstat_incr_irq_this_cpu(irq);
474 		} else if (unlikely(IS_RESCHEDULE(vector))) {
475 			scheduler_ipi();
476 			kstat_incr_irq_this_cpu(irq);
477 		} else {
478 			ia64_setreg(_IA64_REG_CR_TPR, vector);
479 			ia64_srlz_d();
480 
481 			if (unlikely(irq < 0)) {
482 				printk(KERN_ERR "%s: Unexpected interrupt "
483 				       "vector %d on CPU %d is not mapped "
484 				       "to any IRQ!\n", __func__, vector,
485 				       smp_processor_id());
486 			} else
487 				generic_handle_irq(irq);
488 
489 			/*
490 			 * Disable interrupts and send EOI:
491 			 */
492 			local_irq_disable();
493 			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
494 		}
495 		ia64_eoi();
496 		vector = ia64_get_ivr();
497 	}
498 	/*
499 	 * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
500 	 * handler needs to be able to wait for further keyboard interrupts, which can't
501 	 * come through until ia64_eoi() has been done.
502 	 */
503 	irq_exit();
504 	set_irq_regs(old_regs);
505 }
506 
507 #ifdef CONFIG_HOTPLUG_CPU
508 /*
509  * This function emulates a interrupt processing when a cpu is about to be
510  * brought down.
511  */
512 void ia64_process_pending_intr(void)
513 {
514 	ia64_vector vector;
515 	unsigned long saved_tpr;
516 	extern unsigned int vectors_in_migration[NR_IRQS];
517 
518 	vector = ia64_get_ivr();
519 
520 	irq_enter();
521 	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
522 	ia64_srlz_d();
523 
524 	 /*
525 	  * Perform normal interrupt style processing
526 	  */
527 	while (vector != IA64_SPURIOUS_INT_VECTOR) {
528 		int irq = local_vector_to_irq(vector);
529 
530 		if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
531 			smp_local_flush_tlb();
532 			kstat_incr_irq_this_cpu(irq);
533 		} else if (unlikely(IS_RESCHEDULE(vector))) {
534 			kstat_incr_irq_this_cpu(irq);
535 		} else {
536 			struct pt_regs *old_regs = set_irq_regs(NULL);
537 
538 			ia64_setreg(_IA64_REG_CR_TPR, vector);
539 			ia64_srlz_d();
540 
541 			/*
542 			 * Now try calling normal ia64_handle_irq as it would have got called
543 			 * from a real intr handler. Try passing null for pt_regs, hopefully
544 			 * it will work. I hope it works!.
545 			 * Probably could shared code.
546 			 */
547 			if (unlikely(irq < 0)) {
548 				printk(KERN_ERR "%s: Unexpected interrupt "
549 				       "vector %d on CPU %d not being mapped "
550 				       "to any IRQ!!\n", __func__, vector,
551 				       smp_processor_id());
552 			} else {
553 				vectors_in_migration[irq]=0;
554 				generic_handle_irq(irq);
555 			}
556 			set_irq_regs(old_regs);
557 
558 			/*
559 			 * Disable interrupts and send EOI
560 			 */
561 			local_irq_disable();
562 			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
563 		}
564 		ia64_eoi();
565 		vector = ia64_get_ivr();
566 	}
567 	irq_exit();
568 }
569 #endif
570 
571 
572 #ifdef CONFIG_SMP
573 
574 static irqreturn_t dummy_handler (int irq, void *dev_id)
575 {
576 	BUG();
577 	return IRQ_NONE;
578 }
579 
580 /*
581  * KVM uses this interrupt to force a cpu out of guest mode
582  */
583 
584 #endif
585 
586 void
587 register_percpu_irq(ia64_vector vec, irq_handler_t handler, unsigned long flags,
588 		    const char *name)
589 {
590 	unsigned int irq;
591 
592 	irq = vec;
593 	BUG_ON(bind_irq_vector(irq, vec, CPU_MASK_ALL));
594 	irq_set_status_flags(irq, IRQ_PER_CPU);
595 	irq_set_chip(irq, &irq_type_ia64_lsapic);
596 	if (handler)
597 		if (request_irq(irq, handler, flags, name, NULL))
598 			pr_err("Failed to request irq %u (%s)\n", irq, name);
599 	irq_set_handler(irq, handle_percpu_irq);
600 }
601 
602 void __init
603 ia64_native_register_ipi(void)
604 {
605 #ifdef CONFIG_SMP
606 	register_percpu_irq(IA64_IPI_VECTOR, handle_IPI, 0, "IPI");
607 	register_percpu_irq(IA64_IPI_RESCHEDULE, dummy_handler, 0, "resched");
608 	register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, dummy_handler, 0,
609 			    "tlb_flush");
610 #endif
611 }
612 
613 void __init
614 init_IRQ (void)
615 {
616 	acpi_boot_init();
617 	ia64_register_ipi();
618 	register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL, 0, NULL);
619 #ifdef CONFIG_SMP
620 	if (vector_domain_type != VECTOR_DOMAIN_NONE) {
621 		register_percpu_irq(IA64_IRQ_MOVE_VECTOR,
622 				    smp_irq_move_cleanup_interrupt, 0,
623 				    "irq_move");
624 	}
625 #endif
626 }
627 
628 void
629 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
630 {
631 	void __iomem *ipi_addr;
632 	unsigned long ipi_data;
633 	unsigned long phys_cpu_id;
634 
635 	phys_cpu_id = cpu_physical_id(cpu);
636 
637 	/*
638 	 * cpu number is in 8bit ID and 8bit EID
639 	 */
640 
641 	ipi_data = (delivery_mode << 8) | (vector & 0xff);
642 	ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
643 
644 	writeq(ipi_data, ipi_addr);
645 }
646