xref: /openbmc/linux/arch/powerpc/sysdev/xive/common.c (revision 9b135eef)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2016,2017 IBM Corporation.
4  */
5 
6 #define pr_fmt(fmt) "xive: " fmt
7 
8 #include <linux/types.h>
9 #include <linux/threads.h>
10 #include <linux/kernel.h>
11 #include <linux/irq.h>
12 #include <linux/irqdomain.h>
13 #include <linux/debugfs.h>
14 #include <linux/smp.h>
15 #include <linux/interrupt.h>
16 #include <linux/seq_file.h>
17 #include <linux/init.h>
18 #include <linux/cpu.h>
19 #include <linux/of.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22 #include <linux/msi.h>
23 #include <linux/vmalloc.h>
24 
25 #include <asm/io.h>
26 #include <asm/smp.h>
27 #include <asm/machdep.h>
28 #include <asm/irq.h>
29 #include <asm/errno.h>
30 #include <asm/xive.h>
31 #include <asm/xive-regs.h>
32 #include <asm/xmon.h>
33 
34 #include "xive-internal.h"
35 
36 #undef DEBUG_FLUSH
37 #undef DEBUG_ALL
38 
39 #ifdef DEBUG_ALL
40 #define DBG_VERBOSE(fmt, ...)	pr_devel("cpu %d - " fmt, \
41 					 smp_processor_id(), ## __VA_ARGS__)
42 #else
43 #define DBG_VERBOSE(fmt...)	do { } while(0)
44 #endif
45 
46 bool __xive_enabled;
47 EXPORT_SYMBOL_GPL(__xive_enabled);
48 bool xive_cmdline_disabled;
49 
50 /* We use only one priority for now */
51 static u8 xive_irq_priority;
52 
53 /* TIMA exported to KVM */
54 void __iomem *xive_tima;
55 EXPORT_SYMBOL_GPL(xive_tima);
56 u32 xive_tima_offset;
57 
58 /* Backend ops */
59 static const struct xive_ops *xive_ops;
60 
61 /* Our global interrupt domain */
62 static struct irq_domain *xive_irq_domain;
63 
64 #ifdef CONFIG_SMP
65 /* The IPIs use the same logical irq number when on the same chip */
66 static struct xive_ipi_desc {
67 	unsigned int irq;
68 	char name[16];
69 	atomic_t started;
70 } *xive_ipis;
71 
72 /*
73  * Use early_cpu_to_node() for hot-plugged CPUs
74  */
xive_ipi_cpu_to_irq(unsigned int cpu)75 static unsigned int xive_ipi_cpu_to_irq(unsigned int cpu)
76 {
77 	return xive_ipis[early_cpu_to_node(cpu)].irq;
78 }
79 #endif
80 
81 /* Xive state for each CPU */
82 static DEFINE_PER_CPU(struct xive_cpu *, xive_cpu);
83 
84 /* An invalid CPU target */
85 #define XIVE_INVALID_TARGET	(-1)
86 
87 /*
88  * Global toggle to switch on/off StoreEOI
89  */
90 static bool xive_store_eoi = true;
91 
xive_is_store_eoi(struct xive_irq_data * xd)92 static bool xive_is_store_eoi(struct xive_irq_data *xd)
93 {
94 	return xd->flags & XIVE_IRQ_FLAG_STORE_EOI && xive_store_eoi;
95 }
96 
97 /*
98  * Read the next entry in a queue, return its content if it's valid
99  * or 0 if there is no new entry.
100  *
101  * The queue pointer is moved forward unless "just_peek" is set
102  */
xive_read_eq(struct xive_q * q,bool just_peek)103 static u32 xive_read_eq(struct xive_q *q, bool just_peek)
104 {
105 	u32 cur;
106 
107 	if (!q->qpage)
108 		return 0;
109 	cur = be32_to_cpup(q->qpage + q->idx);
110 
111 	/* Check valid bit (31) vs current toggle polarity */
112 	if ((cur >> 31) == q->toggle)
113 		return 0;
114 
115 	/* If consuming from the queue ... */
116 	if (!just_peek) {
117 		/* Next entry */
118 		q->idx = (q->idx + 1) & q->msk;
119 
120 		/* Wrap around: flip valid toggle */
121 		if (q->idx == 0)
122 			q->toggle ^= 1;
123 	}
124 	/* Mask out the valid bit (31) */
125 	return cur & 0x7fffffff;
126 }
127 
128 /*
129  * Scans all the queue that may have interrupts in them
130  * (based on "pending_prio") in priority order until an
131  * interrupt is found or all the queues are empty.
132  *
133  * Then updates the CPPR (Current Processor Priority
134  * Register) based on the most favored interrupt found
135  * (0xff if none) and return what was found (0 if none).
136  *
137  * If just_peek is set, return the most favored pending
138  * interrupt if any but don't update the queue pointers.
139  *
140  * Note: This function can operate generically on any number
141  * of queues (up to 8). The current implementation of the XIVE
142  * driver only uses a single queue however.
143  *
144  * Note2: This will also "flush" "the pending_count" of a queue
145  * into the "count" when that queue is observed to be empty.
146  * This is used to keep track of the amount of interrupts
147  * targetting a queue. When an interrupt is moved away from
148  * a queue, we only decrement that queue count once the queue
149  * has been observed empty to avoid races.
150  */
xive_scan_interrupts(struct xive_cpu * xc,bool just_peek)151 static u32 xive_scan_interrupts(struct xive_cpu *xc, bool just_peek)
152 {
153 	u32 irq = 0;
154 	u8 prio = 0;
155 
156 	/* Find highest pending priority */
157 	while (xc->pending_prio != 0) {
158 		struct xive_q *q;
159 
160 		prio = ffs(xc->pending_prio) - 1;
161 		DBG_VERBOSE("scan_irq: trying prio %d\n", prio);
162 
163 		/* Try to fetch */
164 		irq = xive_read_eq(&xc->queue[prio], just_peek);
165 
166 		/* Found something ? That's it */
167 		if (irq) {
168 			if (just_peek || irq_to_desc(irq))
169 				break;
170 			/*
171 			 * We should never get here; if we do then we must
172 			 * have failed to synchronize the interrupt properly
173 			 * when shutting it down.
174 			 */
175 			pr_crit("xive: got interrupt %d without descriptor, dropping\n",
176 				irq);
177 			WARN_ON(1);
178 			continue;
179 		}
180 
181 		/* Clear pending bits */
182 		xc->pending_prio &= ~(1 << prio);
183 
184 		/*
185 		 * Check if the queue count needs adjusting due to
186 		 * interrupts being moved away. See description of
187 		 * xive_dec_target_count()
188 		 */
189 		q = &xc->queue[prio];
190 		if (atomic_read(&q->pending_count)) {
191 			int p = atomic_xchg(&q->pending_count, 0);
192 			if (p) {
193 				WARN_ON(p > atomic_read(&q->count));
194 				atomic_sub(p, &q->count);
195 			}
196 		}
197 	}
198 
199 	/* If nothing was found, set CPPR to 0xff */
200 	if (irq == 0)
201 		prio = 0xff;
202 
203 	/* Update HW CPPR to match if necessary */
204 	if (prio != xc->cppr) {
205 		DBG_VERBOSE("scan_irq: adjusting CPPR to %d\n", prio);
206 		xc->cppr = prio;
207 		out_8(xive_tima + xive_tima_offset + TM_CPPR, prio);
208 	}
209 
210 	return irq;
211 }
212 
213 /*
214  * This is used to perform the magic loads from an ESB
215  * described in xive-regs.h
216  */
xive_esb_read(struct xive_irq_data * xd,u32 offset)217 static notrace u8 xive_esb_read(struct xive_irq_data *xd, u32 offset)
218 {
219 	u64 val;
220 
221 	if (offset == XIVE_ESB_SET_PQ_10 && xive_is_store_eoi(xd))
222 		offset |= XIVE_ESB_LD_ST_MO;
223 
224 	if ((xd->flags & XIVE_IRQ_FLAG_H_INT_ESB) && xive_ops->esb_rw)
225 		val = xive_ops->esb_rw(xd->hw_irq, offset, 0, 0);
226 	else
227 		val = in_be64(xd->eoi_mmio + offset);
228 
229 	return (u8)val;
230 }
231 
xive_esb_write(struct xive_irq_data * xd,u32 offset,u64 data)232 static void xive_esb_write(struct xive_irq_data *xd, u32 offset, u64 data)
233 {
234 	if ((xd->flags & XIVE_IRQ_FLAG_H_INT_ESB) && xive_ops->esb_rw)
235 		xive_ops->esb_rw(xd->hw_irq, offset, data, 1);
236 	else
237 		out_be64(xd->eoi_mmio + offset, data);
238 }
239 
240 #if defined(CONFIG_XMON) || defined(CONFIG_DEBUG_FS)
xive_irq_data_dump(struct xive_irq_data * xd,char * buffer,size_t size)241 static void xive_irq_data_dump(struct xive_irq_data *xd, char *buffer, size_t size)
242 {
243 	u64 val = xive_esb_read(xd, XIVE_ESB_GET);
244 
245 	snprintf(buffer, size, "flags=%c%c%c PQ=%c%c 0x%016llx 0x%016llx",
246 		 xive_is_store_eoi(xd) ? 'S' : ' ',
247 		 xd->flags & XIVE_IRQ_FLAG_LSI ? 'L' : ' ',
248 		 xd->flags & XIVE_IRQ_FLAG_H_INT_ESB ? 'H' : ' ',
249 		 val & XIVE_ESB_VAL_P ? 'P' : '-',
250 		 val & XIVE_ESB_VAL_Q ? 'Q' : '-',
251 		 xd->trig_page, xd->eoi_page);
252 }
253 #endif
254 
255 #ifdef CONFIG_XMON
xive_dump_eq(const char * name,struct xive_q * q)256 static notrace void xive_dump_eq(const char *name, struct xive_q *q)
257 {
258 	u32 i0, i1, idx;
259 
260 	if (!q->qpage)
261 		return;
262 	idx = q->idx;
263 	i0 = be32_to_cpup(q->qpage + idx);
264 	idx = (idx + 1) & q->msk;
265 	i1 = be32_to_cpup(q->qpage + idx);
266 	xmon_printf("%s idx=%d T=%d %08x %08x ...", name,
267 		     q->idx, q->toggle, i0, i1);
268 }
269 
xmon_xive_do_dump(int cpu)270 notrace void xmon_xive_do_dump(int cpu)
271 {
272 	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
273 
274 	xmon_printf("CPU %d:", cpu);
275 	if (xc) {
276 		xmon_printf("pp=%02x CPPR=%02x ", xc->pending_prio, xc->cppr);
277 
278 #ifdef CONFIG_SMP
279 		{
280 			char buffer[128];
281 
282 			xive_irq_data_dump(&xc->ipi_data, buffer, sizeof(buffer));
283 			xmon_printf("IPI=0x%08x %s", xc->hw_ipi, buffer);
284 		}
285 #endif
286 		xive_dump_eq("EQ", &xc->queue[xive_irq_priority]);
287 	}
288 	xmon_printf("\n");
289 }
290 
xive_get_irq_data(u32 hw_irq)291 static struct irq_data *xive_get_irq_data(u32 hw_irq)
292 {
293 	unsigned int irq = irq_find_mapping(xive_irq_domain, hw_irq);
294 
295 	return irq ? irq_get_irq_data(irq) : NULL;
296 }
297 
xmon_xive_get_irq_config(u32 hw_irq,struct irq_data * d)298 int xmon_xive_get_irq_config(u32 hw_irq, struct irq_data *d)
299 {
300 	int rc;
301 	u32 target;
302 	u8 prio;
303 	u32 lirq;
304 
305 	rc = xive_ops->get_irq_config(hw_irq, &target, &prio, &lirq);
306 	if (rc) {
307 		xmon_printf("IRQ 0x%08x : no config rc=%d\n", hw_irq, rc);
308 		return rc;
309 	}
310 
311 	xmon_printf("IRQ 0x%08x : target=0x%x prio=%02x lirq=0x%x ",
312 		    hw_irq, target, prio, lirq);
313 
314 	if (!d)
315 		d = xive_get_irq_data(hw_irq);
316 
317 	if (d) {
318 		char buffer[128];
319 
320 		xive_irq_data_dump(irq_data_get_irq_handler_data(d),
321 				   buffer, sizeof(buffer));
322 		xmon_printf("%s", buffer);
323 	}
324 
325 	xmon_printf("\n");
326 	return 0;
327 }
328 
xmon_xive_get_irq_all(void)329 void xmon_xive_get_irq_all(void)
330 {
331 	unsigned int i;
332 	struct irq_desc *desc;
333 
334 	for_each_irq_desc(i, desc) {
335 		struct irq_data *d = irq_domain_get_irq_data(xive_irq_domain, i);
336 
337 		if (d)
338 			xmon_xive_get_irq_config(irqd_to_hwirq(d), d);
339 	}
340 }
341 
342 #endif /* CONFIG_XMON */
343 
xive_get_irq(void)344 static unsigned int xive_get_irq(void)
345 {
346 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
347 	u32 irq;
348 
349 	/*
350 	 * This can be called either as a result of a HW interrupt or
351 	 * as a "replay" because EOI decided there was still something
352 	 * in one of the queues.
353 	 *
354 	 * First we perform an ACK cycle in order to update our mask
355 	 * of pending priorities. This will also have the effect of
356 	 * updating the CPPR to the most favored pending interrupts.
357 	 *
358 	 * In the future, if we have a way to differentiate a first
359 	 * entry (on HW interrupt) from a replay triggered by EOI,
360 	 * we could skip this on replays unless we soft-mask tells us
361 	 * that a new HW interrupt occurred.
362 	 */
363 	xive_ops->update_pending(xc);
364 
365 	DBG_VERBOSE("get_irq: pending=%02x\n", xc->pending_prio);
366 
367 	/* Scan our queue(s) for interrupts */
368 	irq = xive_scan_interrupts(xc, false);
369 
370 	DBG_VERBOSE("get_irq: got irq 0x%x, new pending=0x%02x\n",
371 	    irq, xc->pending_prio);
372 
373 	/* Return pending interrupt if any */
374 	if (irq == XIVE_BAD_IRQ)
375 		return 0;
376 	return irq;
377 }
378 
379 /*
380  * After EOI'ing an interrupt, we need to re-check the queue
381  * to see if another interrupt is pending since multiple
382  * interrupts can coalesce into a single notification to the
383  * CPU.
384  *
385  * If we find that there is indeed more in there, we call
386  * force_external_irq_replay() to make Linux synthetize an
387  * external interrupt on the next call to local_irq_restore().
388  */
xive_do_queue_eoi(struct xive_cpu * xc)389 static void xive_do_queue_eoi(struct xive_cpu *xc)
390 {
391 	if (xive_scan_interrupts(xc, true) != 0) {
392 		DBG_VERBOSE("eoi: pending=0x%02x\n", xc->pending_prio);
393 		force_external_irq_replay();
394 	}
395 }
396 
397 /*
398  * EOI an interrupt at the source. There are several methods
399  * to do this depending on the HW version and source type
400  */
xive_do_source_eoi(struct xive_irq_data * xd)401 static void xive_do_source_eoi(struct xive_irq_data *xd)
402 {
403 	u8 eoi_val;
404 
405 	xd->stale_p = false;
406 
407 	/* If the XIVE supports the new "store EOI facility, use it */
408 	if (xive_is_store_eoi(xd)) {
409 		xive_esb_write(xd, XIVE_ESB_STORE_EOI, 0);
410 		return;
411 	}
412 
413 	/*
414 	 * For LSIs, we use the "EOI cycle" special load rather than
415 	 * PQ bits, as they are automatically re-triggered in HW when
416 	 * still pending.
417 	 */
418 	if (xd->flags & XIVE_IRQ_FLAG_LSI) {
419 		xive_esb_read(xd, XIVE_ESB_LOAD_EOI);
420 		return;
421 	}
422 
423 	/*
424 	 * Otherwise, we use the special MMIO that does a clear of
425 	 * both P and Q and returns the old Q. This allows us to then
426 	 * do a re-trigger if Q was set rather than synthesizing an
427 	 * interrupt in software
428 	 */
429 	eoi_val = xive_esb_read(xd, XIVE_ESB_SET_PQ_00);
430 	DBG_VERBOSE("eoi_val=%x\n", eoi_val);
431 
432 	/* Re-trigger if needed */
433 	if ((eoi_val & XIVE_ESB_VAL_Q) && xd->trig_mmio)
434 		out_be64(xd->trig_mmio, 0);
435 }
436 
437 /* irq_chip eoi callback, called with irq descriptor lock held */
xive_irq_eoi(struct irq_data * d)438 static void xive_irq_eoi(struct irq_data *d)
439 {
440 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
441 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
442 
443 	DBG_VERBOSE("eoi_irq: irq=%d [0x%lx] pending=%02x\n",
444 		    d->irq, irqd_to_hwirq(d), xc->pending_prio);
445 
446 	/*
447 	 * EOI the source if it hasn't been disabled and hasn't
448 	 * been passed-through to a KVM guest
449 	 */
450 	if (!irqd_irq_disabled(d) && !irqd_is_forwarded_to_vcpu(d) &&
451 	    !(xd->flags & XIVE_IRQ_FLAG_NO_EOI))
452 		xive_do_source_eoi(xd);
453 	else
454 		xd->stale_p = true;
455 
456 	/*
457 	 * Clear saved_p to indicate that it's no longer occupying
458 	 * a queue slot on the target queue
459 	 */
460 	xd->saved_p = false;
461 
462 	/* Check for more work in the queue */
463 	xive_do_queue_eoi(xc);
464 }
465 
466 /*
467  * Helper used to mask and unmask an interrupt source.
468  */
xive_do_source_set_mask(struct xive_irq_data * xd,bool mask)469 static void xive_do_source_set_mask(struct xive_irq_data *xd,
470 				    bool mask)
471 {
472 	u64 val;
473 
474 	pr_debug("%s: HW 0x%x %smask\n", __func__, xd->hw_irq, mask ? "" : "un");
475 
476 	/*
477 	 * If the interrupt had P set, it may be in a queue.
478 	 *
479 	 * We need to make sure we don't re-enable it until it
480 	 * has been fetched from that queue and EOId. We keep
481 	 * a copy of that P state and use it to restore the
482 	 * ESB accordingly on unmask.
483 	 */
484 	if (mask) {
485 		val = xive_esb_read(xd, XIVE_ESB_SET_PQ_01);
486 		if (!xd->stale_p && !!(val & XIVE_ESB_VAL_P))
487 			xd->saved_p = true;
488 		xd->stale_p = false;
489 	} else if (xd->saved_p) {
490 		xive_esb_read(xd, XIVE_ESB_SET_PQ_10);
491 		xd->saved_p = false;
492 	} else {
493 		xive_esb_read(xd, XIVE_ESB_SET_PQ_00);
494 		xd->stale_p = false;
495 	}
496 }
497 
498 /*
499  * Try to chose "cpu" as a new interrupt target. Increments
500  * the queue accounting for that target if it's not already
501  * full.
502  */
xive_try_pick_target(int cpu)503 static bool xive_try_pick_target(int cpu)
504 {
505 	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
506 	struct xive_q *q = &xc->queue[xive_irq_priority];
507 	int max;
508 
509 	/*
510 	 * Calculate max number of interrupts in that queue.
511 	 *
512 	 * We leave a gap of 1 just in case...
513 	 */
514 	max = (q->msk + 1) - 1;
515 	return !!atomic_add_unless(&q->count, 1, max);
516 }
517 
518 /*
519  * Un-account an interrupt for a target CPU. We don't directly
520  * decrement q->count since the interrupt might still be present
521  * in the queue.
522  *
523  * Instead increment a separate counter "pending_count" which
524  * will be substracted from "count" later when that CPU observes
525  * the queue to be empty.
526  */
xive_dec_target_count(int cpu)527 static void xive_dec_target_count(int cpu)
528 {
529 	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
530 	struct xive_q *q = &xc->queue[xive_irq_priority];
531 
532 	if (WARN_ON(cpu < 0 || !xc)) {
533 		pr_err("%s: cpu=%d xc=%p\n", __func__, cpu, xc);
534 		return;
535 	}
536 
537 	/*
538 	 * We increment the "pending count" which will be used
539 	 * to decrement the target queue count whenever it's next
540 	 * processed and found empty. This ensure that we don't
541 	 * decrement while we still have the interrupt there
542 	 * occupying a slot.
543 	 */
544 	atomic_inc(&q->pending_count);
545 }
546 
547 /* Find a tentative CPU target in a CPU mask */
xive_find_target_in_mask(const struct cpumask * mask,unsigned int fuzz)548 static int xive_find_target_in_mask(const struct cpumask *mask,
549 				    unsigned int fuzz)
550 {
551 	int cpu, first, num, i;
552 
553 	/* Pick up a starting point CPU in the mask based on  fuzz */
554 	num = min_t(int, cpumask_weight(mask), nr_cpu_ids);
555 	first = fuzz % num;
556 
557 	/* Locate it */
558 	cpu = cpumask_first(mask);
559 	for (i = 0; i < first && cpu < nr_cpu_ids; i++)
560 		cpu = cpumask_next(cpu, mask);
561 
562 	/* Sanity check */
563 	if (WARN_ON(cpu >= nr_cpu_ids))
564 		cpu = cpumask_first(cpu_online_mask);
565 
566 	/* Remember first one to handle wrap-around */
567 	first = cpu;
568 
569 	/*
570 	 * Now go through the entire mask until we find a valid
571 	 * target.
572 	 */
573 	do {
574 		/*
575 		 * We re-check online as the fallback case passes us
576 		 * an untested affinity mask
577 		 */
578 		if (cpu_online(cpu) && xive_try_pick_target(cpu))
579 			return cpu;
580 		cpu = cpumask_next(cpu, mask);
581 		/* Wrap around */
582 		if (cpu >= nr_cpu_ids)
583 			cpu = cpumask_first(mask);
584 	} while (cpu != first);
585 
586 	return -1;
587 }
588 
589 /*
590  * Pick a target CPU for an interrupt. This is done at
591  * startup or if the affinity is changed in a way that
592  * invalidates the current target.
593  */
xive_pick_irq_target(struct irq_data * d,const struct cpumask * affinity)594 static int xive_pick_irq_target(struct irq_data *d,
595 				const struct cpumask *affinity)
596 {
597 	static unsigned int fuzz;
598 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
599 	cpumask_var_t mask;
600 	int cpu = -1;
601 
602 	/*
603 	 * If we have chip IDs, first we try to build a mask of
604 	 * CPUs matching the CPU and find a target in there
605 	 */
606 	if (xd->src_chip != XIVE_INVALID_CHIP_ID &&
607 		zalloc_cpumask_var(&mask, GFP_ATOMIC)) {
608 		/* Build a mask of matching chip IDs */
609 		for_each_cpu_and(cpu, affinity, cpu_online_mask) {
610 			struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
611 			if (xc->chip_id == xd->src_chip)
612 				cpumask_set_cpu(cpu, mask);
613 		}
614 		/* Try to find a target */
615 		if (cpumask_empty(mask))
616 			cpu = -1;
617 		else
618 			cpu = xive_find_target_in_mask(mask, fuzz++);
619 		free_cpumask_var(mask);
620 		if (cpu >= 0)
621 			return cpu;
622 		fuzz--;
623 	}
624 
625 	/* No chip IDs, fallback to using the affinity mask */
626 	return xive_find_target_in_mask(affinity, fuzz++);
627 }
628 
xive_irq_startup(struct irq_data * d)629 static unsigned int xive_irq_startup(struct irq_data *d)
630 {
631 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
632 	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
633 	int target, rc;
634 
635 	xd->saved_p = false;
636 	xd->stale_p = false;
637 
638 	pr_debug("%s: irq %d [0x%x] data @%p\n", __func__, d->irq, hw_irq, d);
639 
640 	/* Pick a target */
641 	target = xive_pick_irq_target(d, irq_data_get_affinity_mask(d));
642 	if (target == XIVE_INVALID_TARGET) {
643 		/* Try again breaking affinity */
644 		target = xive_pick_irq_target(d, cpu_online_mask);
645 		if (target == XIVE_INVALID_TARGET)
646 			return -ENXIO;
647 		pr_warn("irq %d started with broken affinity\n", d->irq);
648 	}
649 
650 	/* Sanity check */
651 	if (WARN_ON(target == XIVE_INVALID_TARGET ||
652 		    target >= nr_cpu_ids))
653 		target = smp_processor_id();
654 
655 	xd->target = target;
656 
657 	/*
658 	 * Configure the logical number to be the Linux IRQ number
659 	 * and set the target queue
660 	 */
661 	rc = xive_ops->configure_irq(hw_irq,
662 				     get_hard_smp_processor_id(target),
663 				     xive_irq_priority, d->irq);
664 	if (rc)
665 		return rc;
666 
667 	/* Unmask the ESB */
668 	xive_do_source_set_mask(xd, false);
669 
670 	return 0;
671 }
672 
673 /* called with irq descriptor lock held */
xive_irq_shutdown(struct irq_data * d)674 static void xive_irq_shutdown(struct irq_data *d)
675 {
676 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
677 	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
678 
679 	pr_debug("%s: irq %d [0x%x] data @%p\n", __func__, d->irq, hw_irq, d);
680 
681 	if (WARN_ON(xd->target == XIVE_INVALID_TARGET))
682 		return;
683 
684 	/* Mask the interrupt at the source */
685 	xive_do_source_set_mask(xd, true);
686 
687 	/*
688 	 * Mask the interrupt in HW in the IVT/EAS and set the number
689 	 * to be the "bad" IRQ number
690 	 */
691 	xive_ops->configure_irq(hw_irq,
692 				get_hard_smp_processor_id(xd->target),
693 				0xff, XIVE_BAD_IRQ);
694 
695 	xive_dec_target_count(xd->target);
696 	xd->target = XIVE_INVALID_TARGET;
697 }
698 
xive_irq_unmask(struct irq_data * d)699 static void xive_irq_unmask(struct irq_data *d)
700 {
701 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
702 
703 	pr_debug("%s: irq %d data @%p\n", __func__, d->irq, xd);
704 
705 	xive_do_source_set_mask(xd, false);
706 }
707 
xive_irq_mask(struct irq_data * d)708 static void xive_irq_mask(struct irq_data *d)
709 {
710 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
711 
712 	pr_debug("%s: irq %d data @%p\n", __func__, d->irq, xd);
713 
714 	xive_do_source_set_mask(xd, true);
715 }
716 
xive_irq_set_affinity(struct irq_data * d,const struct cpumask * cpumask,bool force)717 static int xive_irq_set_affinity(struct irq_data *d,
718 				 const struct cpumask *cpumask,
719 				 bool force)
720 {
721 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
722 	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
723 	u32 target, old_target;
724 	int rc = 0;
725 
726 	pr_debug("%s: irq %d/0x%x\n", __func__, d->irq, hw_irq);
727 
728 	/* Is this valid ? */
729 	if (cpumask_any_and(cpumask, cpu_online_mask) >= nr_cpu_ids)
730 		return -EINVAL;
731 
732 	/*
733 	 * If existing target is already in the new mask, and is
734 	 * online then do nothing.
735 	 */
736 	if (xd->target != XIVE_INVALID_TARGET &&
737 	    cpu_online(xd->target) &&
738 	    cpumask_test_cpu(xd->target, cpumask))
739 		return IRQ_SET_MASK_OK;
740 
741 	/* Pick a new target */
742 	target = xive_pick_irq_target(d, cpumask);
743 
744 	/* No target found */
745 	if (target == XIVE_INVALID_TARGET)
746 		return -ENXIO;
747 
748 	/* Sanity check */
749 	if (WARN_ON(target >= nr_cpu_ids))
750 		target = smp_processor_id();
751 
752 	old_target = xd->target;
753 
754 	/*
755 	 * Only configure the irq if it's not currently passed-through to
756 	 * a KVM guest
757 	 */
758 	if (!irqd_is_forwarded_to_vcpu(d))
759 		rc = xive_ops->configure_irq(hw_irq,
760 					     get_hard_smp_processor_id(target),
761 					     xive_irq_priority, d->irq);
762 	if (rc < 0) {
763 		pr_err("Error %d reconfiguring irq %d\n", rc, d->irq);
764 		return rc;
765 	}
766 
767 	pr_debug("  target: 0x%x\n", target);
768 	xd->target = target;
769 
770 	/* Give up previous target */
771 	if (old_target != XIVE_INVALID_TARGET)
772 	    xive_dec_target_count(old_target);
773 
774 	return IRQ_SET_MASK_OK;
775 }
776 
xive_irq_set_type(struct irq_data * d,unsigned int flow_type)777 static int xive_irq_set_type(struct irq_data *d, unsigned int flow_type)
778 {
779 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
780 
781 	/*
782 	 * We only support these. This has really no effect other than setting
783 	 * the corresponding descriptor bits mind you but those will in turn
784 	 * affect the resend function when re-enabling an edge interrupt.
785 	 *
786 	 * Set the default to edge as explained in map().
787 	 */
788 	if (flow_type == IRQ_TYPE_DEFAULT || flow_type == IRQ_TYPE_NONE)
789 		flow_type = IRQ_TYPE_EDGE_RISING;
790 
791 	if (flow_type != IRQ_TYPE_EDGE_RISING &&
792 	    flow_type != IRQ_TYPE_LEVEL_LOW)
793 		return -EINVAL;
794 
795 	irqd_set_trigger_type(d, flow_type);
796 
797 	/*
798 	 * Double check it matches what the FW thinks
799 	 *
800 	 * NOTE: We don't know yet if the PAPR interface will provide
801 	 * the LSI vs MSI information apart from the device-tree so
802 	 * this check might have to move into an optional backend call
803 	 * that is specific to the native backend
804 	 */
805 	if ((flow_type == IRQ_TYPE_LEVEL_LOW) !=
806 	    !!(xd->flags & XIVE_IRQ_FLAG_LSI)) {
807 		pr_warn("Interrupt %d (HW 0x%x) type mismatch, Linux says %s, FW says %s\n",
808 			d->irq, (u32)irqd_to_hwirq(d),
809 			(flow_type == IRQ_TYPE_LEVEL_LOW) ? "Level" : "Edge",
810 			(xd->flags & XIVE_IRQ_FLAG_LSI) ? "Level" : "Edge");
811 	}
812 
813 	return IRQ_SET_MASK_OK_NOCOPY;
814 }
815 
xive_irq_retrigger(struct irq_data * d)816 static int xive_irq_retrigger(struct irq_data *d)
817 {
818 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
819 
820 	/* This should be only for MSIs */
821 	if (WARN_ON(xd->flags & XIVE_IRQ_FLAG_LSI))
822 		return 0;
823 
824 	/*
825 	 * To perform a retrigger, we first set the PQ bits to
826 	 * 11, then perform an EOI.
827 	 */
828 	xive_esb_read(xd, XIVE_ESB_SET_PQ_11);
829 	xive_do_source_eoi(xd);
830 
831 	return 1;
832 }
833 
834 /*
835  * Caller holds the irq descriptor lock, so this won't be called
836  * concurrently with xive_get_irqchip_state on the same interrupt.
837  */
xive_irq_set_vcpu_affinity(struct irq_data * d,void * state)838 static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
839 {
840 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
841 	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
842 	int rc;
843 	u8 pq;
844 
845 	/*
846 	 * This is called by KVM with state non-NULL for enabling
847 	 * pass-through or NULL for disabling it
848 	 */
849 	if (state) {
850 		irqd_set_forwarded_to_vcpu(d);
851 
852 		/* Set it to PQ=10 state to prevent further sends */
853 		pq = xive_esb_read(xd, XIVE_ESB_SET_PQ_10);
854 		if (!xd->stale_p) {
855 			xd->saved_p = !!(pq & XIVE_ESB_VAL_P);
856 			xd->stale_p = !xd->saved_p;
857 		}
858 
859 		/* No target ? nothing to do */
860 		if (xd->target == XIVE_INVALID_TARGET) {
861 			/*
862 			 * An untargetted interrupt should have been
863 			 * also masked at the source
864 			 */
865 			WARN_ON(xd->saved_p);
866 
867 			return 0;
868 		}
869 
870 		/*
871 		 * If P was set, adjust state to PQ=11 to indicate
872 		 * that a resend is needed for the interrupt to reach
873 		 * the guest. Also remember the value of P.
874 		 *
875 		 * This also tells us that it's in flight to a host queue
876 		 * or has already been fetched but hasn't been EOIed yet
877 		 * by the host. This it's potentially using up a host
878 		 * queue slot. This is important to know because as long
879 		 * as this is the case, we must not hard-unmask it when
880 		 * "returning" that interrupt to the host.
881 		 *
882 		 * This saved_p is cleared by the host EOI, when we know
883 		 * for sure the queue slot is no longer in use.
884 		 */
885 		if (xd->saved_p) {
886 			xive_esb_read(xd, XIVE_ESB_SET_PQ_11);
887 
888 			/*
889 			 * Sync the XIVE source HW to ensure the interrupt
890 			 * has gone through the EAS before we change its
891 			 * target to the guest. That should guarantee us
892 			 * that we *will* eventually get an EOI for it on
893 			 * the host. Otherwise there would be a small window
894 			 * for P to be seen here but the interrupt going
895 			 * to the guest queue.
896 			 */
897 			if (xive_ops->sync_source)
898 				xive_ops->sync_source(hw_irq);
899 		}
900 	} else {
901 		irqd_clr_forwarded_to_vcpu(d);
902 
903 		/* No host target ? hard mask and return */
904 		if (xd->target == XIVE_INVALID_TARGET) {
905 			xive_do_source_set_mask(xd, true);
906 			return 0;
907 		}
908 
909 		/*
910 		 * Sync the XIVE source HW to ensure the interrupt
911 		 * has gone through the EAS before we change its
912 		 * target to the host.
913 		 */
914 		if (xive_ops->sync_source)
915 			xive_ops->sync_source(hw_irq);
916 
917 		/*
918 		 * By convention we are called with the interrupt in
919 		 * a PQ=10 or PQ=11 state, ie, it won't fire and will
920 		 * have latched in Q whether there's a pending HW
921 		 * interrupt or not.
922 		 *
923 		 * First reconfigure the target.
924 		 */
925 		rc = xive_ops->configure_irq(hw_irq,
926 					     get_hard_smp_processor_id(xd->target),
927 					     xive_irq_priority, d->irq);
928 		if (rc)
929 			return rc;
930 
931 		/*
932 		 * Then if saved_p is not set, effectively re-enable the
933 		 * interrupt with an EOI. If it is set, we know there is
934 		 * still a message in a host queue somewhere that will be
935 		 * EOId eventually.
936 		 *
937 		 * Note: We don't check irqd_irq_disabled(). Effectively,
938 		 * we *will* let the irq get through even if masked if the
939 		 * HW is still firing it in order to deal with the whole
940 		 * saved_p business properly. If the interrupt triggers
941 		 * while masked, the generic code will re-mask it anyway.
942 		 */
943 		if (!xd->saved_p)
944 			xive_do_source_eoi(xd);
945 
946 	}
947 	return 0;
948 }
949 
950 /* Called with irq descriptor lock held. */
xive_get_irqchip_state(struct irq_data * data,enum irqchip_irq_state which,bool * state)951 static int xive_get_irqchip_state(struct irq_data *data,
952 				  enum irqchip_irq_state which, bool *state)
953 {
954 	struct xive_irq_data *xd = irq_data_get_irq_handler_data(data);
955 	u8 pq;
956 
957 	switch (which) {
958 	case IRQCHIP_STATE_ACTIVE:
959 		pq = xive_esb_read(xd, XIVE_ESB_GET);
960 
961 		/*
962 		 * The esb value being all 1's means we couldn't get
963 		 * the PQ state of the interrupt through mmio. It may
964 		 * happen, for example when querying a PHB interrupt
965 		 * while the PHB is in an error state. We consider the
966 		 * interrupt to be inactive in that case.
967 		 */
968 		*state = (pq != XIVE_ESB_INVALID) && !xd->stale_p &&
969 			(xd->saved_p || (!!(pq & XIVE_ESB_VAL_P) &&
970 			 !irqd_irq_disabled(data)));
971 		return 0;
972 	default:
973 		return -EINVAL;
974 	}
975 }
976 
977 static struct irq_chip xive_irq_chip = {
978 	.name = "XIVE-IRQ",
979 	.irq_startup = xive_irq_startup,
980 	.irq_shutdown = xive_irq_shutdown,
981 	.irq_eoi = xive_irq_eoi,
982 	.irq_mask = xive_irq_mask,
983 	.irq_unmask = xive_irq_unmask,
984 	.irq_set_affinity = xive_irq_set_affinity,
985 	.irq_set_type = xive_irq_set_type,
986 	.irq_retrigger = xive_irq_retrigger,
987 	.irq_set_vcpu_affinity = xive_irq_set_vcpu_affinity,
988 	.irq_get_irqchip_state = xive_get_irqchip_state,
989 };
990 
is_xive_irq(struct irq_chip * chip)991 bool is_xive_irq(struct irq_chip *chip)
992 {
993 	return chip == &xive_irq_chip;
994 }
995 EXPORT_SYMBOL_GPL(is_xive_irq);
996 
xive_cleanup_irq_data(struct xive_irq_data * xd)997 void xive_cleanup_irq_data(struct xive_irq_data *xd)
998 {
999 	pr_debug("%s for HW 0x%x\n", __func__, xd->hw_irq);
1000 
1001 	if (xd->eoi_mmio) {
1002 		iounmap(xd->eoi_mmio);
1003 		if (xd->eoi_mmio == xd->trig_mmio)
1004 			xd->trig_mmio = NULL;
1005 		xd->eoi_mmio = NULL;
1006 	}
1007 	if (xd->trig_mmio) {
1008 		iounmap(xd->trig_mmio);
1009 		xd->trig_mmio = NULL;
1010 	}
1011 }
1012 EXPORT_SYMBOL_GPL(xive_cleanup_irq_data);
1013 
xive_irq_alloc_data(unsigned int virq,irq_hw_number_t hw)1014 static int xive_irq_alloc_data(unsigned int virq, irq_hw_number_t hw)
1015 {
1016 	struct xive_irq_data *xd;
1017 	int rc;
1018 
1019 	xd = kzalloc(sizeof(struct xive_irq_data), GFP_KERNEL);
1020 	if (!xd)
1021 		return -ENOMEM;
1022 	rc = xive_ops->populate_irq_data(hw, xd);
1023 	if (rc) {
1024 		kfree(xd);
1025 		return rc;
1026 	}
1027 	xd->target = XIVE_INVALID_TARGET;
1028 	irq_set_handler_data(virq, xd);
1029 
1030 	/*
1031 	 * Turn OFF by default the interrupt being mapped. A side
1032 	 * effect of this check is the mapping the ESB page of the
1033 	 * interrupt in the Linux address space. This prevents page
1034 	 * fault issues in the crash handler which masks all
1035 	 * interrupts.
1036 	 */
1037 	xive_esb_read(xd, XIVE_ESB_SET_PQ_01);
1038 
1039 	return 0;
1040 }
1041 
xive_irq_free_data(unsigned int virq)1042 void xive_irq_free_data(unsigned int virq)
1043 {
1044 	struct xive_irq_data *xd = irq_get_handler_data(virq);
1045 
1046 	if (!xd)
1047 		return;
1048 	irq_set_handler_data(virq, NULL);
1049 	xive_cleanup_irq_data(xd);
1050 	kfree(xd);
1051 }
1052 EXPORT_SYMBOL_GPL(xive_irq_free_data);
1053 
1054 #ifdef CONFIG_SMP
1055 
xive_cause_ipi(int cpu)1056 static void xive_cause_ipi(int cpu)
1057 {
1058 	struct xive_cpu *xc;
1059 	struct xive_irq_data *xd;
1060 
1061 	xc = per_cpu(xive_cpu, cpu);
1062 
1063 	DBG_VERBOSE("IPI CPU %d -> %d (HW IRQ 0x%x)\n",
1064 		    smp_processor_id(), cpu, xc->hw_ipi);
1065 
1066 	xd = &xc->ipi_data;
1067 	if (WARN_ON(!xd->trig_mmio))
1068 		return;
1069 	out_be64(xd->trig_mmio, 0);
1070 }
1071 
xive_muxed_ipi_action(int irq,void * dev_id)1072 static irqreturn_t xive_muxed_ipi_action(int irq, void *dev_id)
1073 {
1074 	return smp_ipi_demux();
1075 }
1076 
xive_ipi_eoi(struct irq_data * d)1077 static void xive_ipi_eoi(struct irq_data *d)
1078 {
1079 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
1080 
1081 	/* Handle possible race with unplug and drop stale IPIs */
1082 	if (!xc)
1083 		return;
1084 
1085 	DBG_VERBOSE("IPI eoi: irq=%d [0x%lx] (HW IRQ 0x%x) pending=%02x\n",
1086 		    d->irq, irqd_to_hwirq(d), xc->hw_ipi, xc->pending_prio);
1087 
1088 	xive_do_source_eoi(&xc->ipi_data);
1089 	xive_do_queue_eoi(xc);
1090 }
1091 
xive_ipi_do_nothing(struct irq_data * d)1092 static void xive_ipi_do_nothing(struct irq_data *d)
1093 {
1094 	/*
1095 	 * Nothing to do, we never mask/unmask IPIs, but the callback
1096 	 * has to exist for the struct irq_chip.
1097 	 */
1098 }
1099 
1100 static struct irq_chip xive_ipi_chip = {
1101 	.name = "XIVE-IPI",
1102 	.irq_eoi = xive_ipi_eoi,
1103 	.irq_mask = xive_ipi_do_nothing,
1104 	.irq_unmask = xive_ipi_do_nothing,
1105 };
1106 
1107 /*
1108  * IPIs are marked per-cpu. We use separate HW interrupts under the
1109  * hood but associated with the same "linux" interrupt
1110  */
1111 struct xive_ipi_alloc_info {
1112 	irq_hw_number_t hwirq;
1113 };
1114 
xive_ipi_irq_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)1115 static int xive_ipi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
1116 				     unsigned int nr_irqs, void *arg)
1117 {
1118 	struct xive_ipi_alloc_info *info = arg;
1119 	int i;
1120 
1121 	for (i = 0; i < nr_irqs; i++) {
1122 		irq_domain_set_info(domain, virq + i, info->hwirq + i, &xive_ipi_chip,
1123 				    domain->host_data, handle_percpu_irq,
1124 				    NULL, NULL);
1125 	}
1126 	return 0;
1127 }
1128 
1129 static const struct irq_domain_ops xive_ipi_irq_domain_ops = {
1130 	.alloc  = xive_ipi_irq_domain_alloc,
1131 };
1132 
xive_init_ipis(void)1133 static int __init xive_init_ipis(void)
1134 {
1135 	struct fwnode_handle *fwnode;
1136 	struct irq_domain *ipi_domain;
1137 	unsigned int node;
1138 	int ret = -ENOMEM;
1139 
1140 	fwnode = irq_domain_alloc_named_fwnode("XIVE-IPI");
1141 	if (!fwnode)
1142 		goto out;
1143 
1144 	ipi_domain = irq_domain_create_linear(fwnode, nr_node_ids,
1145 					      &xive_ipi_irq_domain_ops, NULL);
1146 	if (!ipi_domain)
1147 		goto out_free_fwnode;
1148 
1149 	xive_ipis = kcalloc(nr_node_ids, sizeof(*xive_ipis), GFP_KERNEL | __GFP_NOFAIL);
1150 	if (!xive_ipis)
1151 		goto out_free_domain;
1152 
1153 	for_each_node(node) {
1154 		struct xive_ipi_desc *xid = &xive_ipis[node];
1155 		struct xive_ipi_alloc_info info = { node };
1156 
1157 		/*
1158 		 * Map one IPI interrupt per node for all cpus of that node.
1159 		 * Since the HW interrupt number doesn't have any meaning,
1160 		 * simply use the node number.
1161 		 */
1162 		ret = irq_domain_alloc_irqs(ipi_domain, 1, node, &info);
1163 		if (ret < 0)
1164 			goto out_free_xive_ipis;
1165 		xid->irq = ret;
1166 
1167 		snprintf(xid->name, sizeof(xid->name), "IPI-%d", node);
1168 	}
1169 
1170 	return ret;
1171 
1172 out_free_xive_ipis:
1173 	kfree(xive_ipis);
1174 out_free_domain:
1175 	irq_domain_remove(ipi_domain);
1176 out_free_fwnode:
1177 	irq_domain_free_fwnode(fwnode);
1178 out:
1179 	return ret;
1180 }
1181 
xive_request_ipi(unsigned int cpu)1182 static int xive_request_ipi(unsigned int cpu)
1183 {
1184 	struct xive_ipi_desc *xid = &xive_ipis[early_cpu_to_node(cpu)];
1185 	int ret;
1186 
1187 	if (atomic_inc_return(&xid->started) > 1)
1188 		return 0;
1189 
1190 	ret = request_irq(xid->irq, xive_muxed_ipi_action,
1191 			  IRQF_NO_DEBUG | IRQF_PERCPU | IRQF_NO_THREAD,
1192 			  xid->name, NULL);
1193 
1194 	WARN(ret < 0, "Failed to request IPI %d: %d\n", xid->irq, ret);
1195 	return ret;
1196 }
1197 
xive_setup_cpu_ipi(unsigned int cpu)1198 static int xive_setup_cpu_ipi(unsigned int cpu)
1199 {
1200 	unsigned int xive_ipi_irq = xive_ipi_cpu_to_irq(cpu);
1201 	struct xive_cpu *xc;
1202 	int rc;
1203 
1204 	pr_debug("Setting up IPI for CPU %d\n", cpu);
1205 
1206 	xc = per_cpu(xive_cpu, cpu);
1207 
1208 	/* Check if we are already setup */
1209 	if (xc->hw_ipi != XIVE_BAD_IRQ)
1210 		return 0;
1211 
1212 	/* Register the IPI */
1213 	xive_request_ipi(cpu);
1214 
1215 	/* Grab an IPI from the backend, this will populate xc->hw_ipi */
1216 	if (xive_ops->get_ipi(cpu, xc))
1217 		return -EIO;
1218 
1219 	/*
1220 	 * Populate the IRQ data in the xive_cpu structure and
1221 	 * configure the HW / enable the IPIs.
1222 	 */
1223 	rc = xive_ops->populate_irq_data(xc->hw_ipi, &xc->ipi_data);
1224 	if (rc) {
1225 		pr_err("Failed to populate IPI data on CPU %d\n", cpu);
1226 		return -EIO;
1227 	}
1228 	rc = xive_ops->configure_irq(xc->hw_ipi,
1229 				     get_hard_smp_processor_id(cpu),
1230 				     xive_irq_priority, xive_ipi_irq);
1231 	if (rc) {
1232 		pr_err("Failed to map IPI CPU %d\n", cpu);
1233 		return -EIO;
1234 	}
1235 	pr_debug("CPU %d HW IPI 0x%x, virq %d, trig_mmio=%p\n", cpu,
1236 		 xc->hw_ipi, xive_ipi_irq, xc->ipi_data.trig_mmio);
1237 
1238 	/* Unmask it */
1239 	xive_do_source_set_mask(&xc->ipi_data, false);
1240 
1241 	return 0;
1242 }
1243 
xive_cleanup_cpu_ipi(unsigned int cpu,struct xive_cpu * xc)1244 noinstr static void xive_cleanup_cpu_ipi(unsigned int cpu, struct xive_cpu *xc)
1245 {
1246 	unsigned int xive_ipi_irq = xive_ipi_cpu_to_irq(cpu);
1247 
1248 	/* Disable the IPI and free the IRQ data */
1249 
1250 	/* Already cleaned up ? */
1251 	if (xc->hw_ipi == XIVE_BAD_IRQ)
1252 		return;
1253 
1254 	/* TODO: clear IPI mapping */
1255 
1256 	/* Mask the IPI */
1257 	xive_do_source_set_mask(&xc->ipi_data, true);
1258 
1259 	/*
1260 	 * Note: We don't call xive_cleanup_irq_data() to free
1261 	 * the mappings as this is called from an IPI on kexec
1262 	 * which is not a safe environment to call iounmap()
1263 	 */
1264 
1265 	/* Deconfigure/mask in the backend */
1266 	xive_ops->configure_irq(xc->hw_ipi, hard_smp_processor_id(),
1267 				0xff, xive_ipi_irq);
1268 
1269 	/* Free the IPIs in the backend */
1270 	xive_ops->put_ipi(cpu, xc);
1271 }
1272 
xive_smp_probe(void)1273 void __init xive_smp_probe(void)
1274 {
1275 	smp_ops->cause_ipi = xive_cause_ipi;
1276 
1277 	/* Register the IPI */
1278 	xive_init_ipis();
1279 
1280 	/* Allocate and setup IPI for the boot CPU */
1281 	xive_setup_cpu_ipi(smp_processor_id());
1282 }
1283 
1284 #endif /* CONFIG_SMP */
1285 
xive_irq_domain_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw)1286 static int xive_irq_domain_map(struct irq_domain *h, unsigned int virq,
1287 			       irq_hw_number_t hw)
1288 {
1289 	int rc;
1290 
1291 	/*
1292 	 * Mark interrupts as edge sensitive by default so that resend
1293 	 * actually works. Will fix that up below if needed.
1294 	 */
1295 	irq_clear_status_flags(virq, IRQ_LEVEL);
1296 
1297 	rc = xive_irq_alloc_data(virq, hw);
1298 	if (rc)
1299 		return rc;
1300 
1301 	irq_set_chip_and_handler(virq, &xive_irq_chip, handle_fasteoi_irq);
1302 
1303 	return 0;
1304 }
1305 
xive_irq_domain_unmap(struct irq_domain * d,unsigned int virq)1306 static void xive_irq_domain_unmap(struct irq_domain *d, unsigned int virq)
1307 {
1308 	xive_irq_free_data(virq);
1309 }
1310 
xive_irq_domain_xlate(struct irq_domain * h,struct device_node * ct,const u32 * intspec,unsigned int intsize,irq_hw_number_t * out_hwirq,unsigned int * out_flags)1311 static int xive_irq_domain_xlate(struct irq_domain *h, struct device_node *ct,
1312 				 const u32 *intspec, unsigned int intsize,
1313 				 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
1314 
1315 {
1316 	*out_hwirq = intspec[0];
1317 
1318 	/*
1319 	 * If intsize is at least 2, we look for the type in the second cell,
1320 	 * we assume the LSB indicates a level interrupt.
1321 	 */
1322 	if (intsize > 1) {
1323 		if (intspec[1] & 1)
1324 			*out_flags = IRQ_TYPE_LEVEL_LOW;
1325 		else
1326 			*out_flags = IRQ_TYPE_EDGE_RISING;
1327 	} else
1328 		*out_flags = IRQ_TYPE_LEVEL_LOW;
1329 
1330 	return 0;
1331 }
1332 
xive_irq_domain_match(struct irq_domain * h,struct device_node * node,enum irq_domain_bus_token bus_token)1333 static int xive_irq_domain_match(struct irq_domain *h, struct device_node *node,
1334 				 enum irq_domain_bus_token bus_token)
1335 {
1336 	return xive_ops->match(node);
1337 }
1338 
1339 #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
1340 static const char * const esb_names[] = { "RESET", "OFF", "PENDING", "QUEUED" };
1341 
1342 static const struct {
1343 	u64  mask;
1344 	char *name;
1345 } xive_irq_flags[] = {
1346 	{ XIVE_IRQ_FLAG_STORE_EOI, "STORE_EOI" },
1347 	{ XIVE_IRQ_FLAG_LSI,       "LSI"       },
1348 	{ XIVE_IRQ_FLAG_H_INT_ESB, "H_INT_ESB" },
1349 	{ XIVE_IRQ_FLAG_NO_EOI,    "NO_EOI"    },
1350 };
1351 
xive_irq_domain_debug_show(struct seq_file * m,struct irq_domain * d,struct irq_data * irqd,int ind)1352 static void xive_irq_domain_debug_show(struct seq_file *m, struct irq_domain *d,
1353 				       struct irq_data *irqd, int ind)
1354 {
1355 	struct xive_irq_data *xd;
1356 	u64 val;
1357 	int i;
1358 
1359 	/* No IRQ domain level information. To be done */
1360 	if (!irqd)
1361 		return;
1362 
1363 	if (!is_xive_irq(irq_data_get_irq_chip(irqd)))
1364 		return;
1365 
1366 	seq_printf(m, "%*sXIVE:\n", ind, "");
1367 	ind++;
1368 
1369 	xd = irq_data_get_irq_handler_data(irqd);
1370 	if (!xd) {
1371 		seq_printf(m, "%*snot assigned\n", ind, "");
1372 		return;
1373 	}
1374 
1375 	val = xive_esb_read(xd, XIVE_ESB_GET);
1376 	seq_printf(m, "%*sESB:      %s\n", ind, "", esb_names[val & 0x3]);
1377 	seq_printf(m, "%*sPstate:   %s %s\n", ind, "", xd->stale_p ? "stale" : "",
1378 		   xd->saved_p ? "saved" : "");
1379 	seq_printf(m, "%*sTarget:   %d\n", ind, "", xd->target);
1380 	seq_printf(m, "%*sChip:     %d\n", ind, "", xd->src_chip);
1381 	seq_printf(m, "%*sTrigger:  0x%016llx\n", ind, "", xd->trig_page);
1382 	seq_printf(m, "%*sEOI:      0x%016llx\n", ind, "", xd->eoi_page);
1383 	seq_printf(m, "%*sFlags:    0x%llx\n", ind, "", xd->flags);
1384 	for (i = 0; i < ARRAY_SIZE(xive_irq_flags); i++) {
1385 		if (xd->flags & xive_irq_flags[i].mask)
1386 			seq_printf(m, "%*s%s\n", ind + 12, "", xive_irq_flags[i].name);
1387 	}
1388 }
1389 #endif
1390 
1391 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
xive_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1392 static int xive_irq_domain_translate(struct irq_domain *d,
1393 				     struct irq_fwspec *fwspec,
1394 				     unsigned long *hwirq,
1395 				     unsigned int *type)
1396 {
1397 	return xive_irq_domain_xlate(d, to_of_node(fwspec->fwnode),
1398 				     fwspec->param, fwspec->param_count,
1399 				     hwirq, type);
1400 }
1401 
xive_irq_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)1402 static int xive_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
1403 				 unsigned int nr_irqs, void *arg)
1404 {
1405 	struct irq_fwspec *fwspec = arg;
1406 	irq_hw_number_t hwirq;
1407 	unsigned int type = IRQ_TYPE_NONE;
1408 	int i, rc;
1409 
1410 	rc = xive_irq_domain_translate(domain, fwspec, &hwirq, &type);
1411 	if (rc)
1412 		return rc;
1413 
1414 	pr_debug("%s %d/0x%lx #%d\n", __func__, virq, hwirq, nr_irqs);
1415 
1416 	for (i = 0; i < nr_irqs; i++) {
1417 		/* TODO: call xive_irq_domain_map() */
1418 
1419 		/*
1420 		 * Mark interrupts as edge sensitive by default so that resend
1421 		 * actually works. Will fix that up below if needed.
1422 		 */
1423 		irq_clear_status_flags(virq, IRQ_LEVEL);
1424 
1425 		/* allocates and sets handler data */
1426 		rc = xive_irq_alloc_data(virq + i, hwirq + i);
1427 		if (rc)
1428 			return rc;
1429 
1430 		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
1431 					      &xive_irq_chip, domain->host_data);
1432 		irq_set_handler(virq + i, handle_fasteoi_irq);
1433 	}
1434 
1435 	return 0;
1436 }
1437 
xive_irq_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)1438 static void xive_irq_domain_free(struct irq_domain *domain,
1439 				 unsigned int virq, unsigned int nr_irqs)
1440 {
1441 	int i;
1442 
1443 	pr_debug("%s %d #%d\n", __func__, virq, nr_irqs);
1444 
1445 	for (i = 0; i < nr_irqs; i++)
1446 		xive_irq_free_data(virq + i);
1447 }
1448 #endif
1449 
1450 static const struct irq_domain_ops xive_irq_domain_ops = {
1451 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
1452 	.alloc	= xive_irq_domain_alloc,
1453 	.free	= xive_irq_domain_free,
1454 	.translate = xive_irq_domain_translate,
1455 #endif
1456 	.match = xive_irq_domain_match,
1457 	.map = xive_irq_domain_map,
1458 	.unmap = xive_irq_domain_unmap,
1459 	.xlate = xive_irq_domain_xlate,
1460 #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
1461 	.debug_show = xive_irq_domain_debug_show,
1462 #endif
1463 };
1464 
xive_init_host(struct device_node * np)1465 static void __init xive_init_host(struct device_node *np)
1466 {
1467 	xive_irq_domain = irq_domain_add_tree(np, &xive_irq_domain_ops, NULL);
1468 	if (WARN_ON(xive_irq_domain == NULL))
1469 		return;
1470 	irq_set_default_host(xive_irq_domain);
1471 }
1472 
xive_cleanup_cpu_queues(unsigned int cpu,struct xive_cpu * xc)1473 static void xive_cleanup_cpu_queues(unsigned int cpu, struct xive_cpu *xc)
1474 {
1475 	if (xc->queue[xive_irq_priority].qpage)
1476 		xive_ops->cleanup_queue(cpu, xc, xive_irq_priority);
1477 }
1478 
xive_setup_cpu_queues(unsigned int cpu,struct xive_cpu * xc)1479 static int xive_setup_cpu_queues(unsigned int cpu, struct xive_cpu *xc)
1480 {
1481 	int rc = 0;
1482 
1483 	/* We setup 1 queues for now with a 64k page */
1484 	if (!xc->queue[xive_irq_priority].qpage)
1485 		rc = xive_ops->setup_queue(cpu, xc, xive_irq_priority);
1486 
1487 	return rc;
1488 }
1489 
xive_prepare_cpu(unsigned int cpu)1490 static int xive_prepare_cpu(unsigned int cpu)
1491 {
1492 	struct xive_cpu *xc;
1493 
1494 	xc = per_cpu(xive_cpu, cpu);
1495 	if (!xc) {
1496 		xc = kzalloc_node(sizeof(struct xive_cpu),
1497 				  GFP_KERNEL, cpu_to_node(cpu));
1498 		if (!xc)
1499 			return -ENOMEM;
1500 		xc->hw_ipi = XIVE_BAD_IRQ;
1501 		xc->chip_id = XIVE_INVALID_CHIP_ID;
1502 		if (xive_ops->prepare_cpu)
1503 			xive_ops->prepare_cpu(cpu, xc);
1504 
1505 		per_cpu(xive_cpu, cpu) = xc;
1506 	}
1507 
1508 	/* Setup EQs if not already */
1509 	return xive_setup_cpu_queues(cpu, xc);
1510 }
1511 
xive_setup_cpu(void)1512 static void xive_setup_cpu(void)
1513 {
1514 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
1515 
1516 	/* The backend might have additional things to do */
1517 	if (xive_ops->setup_cpu)
1518 		xive_ops->setup_cpu(smp_processor_id(), xc);
1519 
1520 	/* Set CPPR to 0xff to enable flow of interrupts */
1521 	xc->cppr = 0xff;
1522 	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0xff);
1523 }
1524 
1525 #ifdef CONFIG_SMP
xive_smp_setup_cpu(void)1526 void xive_smp_setup_cpu(void)
1527 {
1528 	pr_debug("SMP setup CPU %d\n", smp_processor_id());
1529 
1530 	/* This will have already been done on the boot CPU */
1531 	if (smp_processor_id() != boot_cpuid)
1532 		xive_setup_cpu();
1533 
1534 }
1535 
xive_smp_prepare_cpu(unsigned int cpu)1536 int xive_smp_prepare_cpu(unsigned int cpu)
1537 {
1538 	int rc;
1539 
1540 	/* Allocate per-CPU data and queues */
1541 	rc = xive_prepare_cpu(cpu);
1542 	if (rc)
1543 		return rc;
1544 
1545 	/* Allocate and setup IPI for the new CPU */
1546 	return xive_setup_cpu_ipi(cpu);
1547 }
1548 
1549 #ifdef CONFIG_HOTPLUG_CPU
xive_flush_cpu_queue(unsigned int cpu,struct xive_cpu * xc)1550 static void xive_flush_cpu_queue(unsigned int cpu, struct xive_cpu *xc)
1551 {
1552 	u32 irq;
1553 
1554 	/* We assume local irqs are disabled */
1555 	WARN_ON(!irqs_disabled());
1556 
1557 	/* Check what's already in the CPU queue */
1558 	while ((irq = xive_scan_interrupts(xc, false)) != 0) {
1559 		/*
1560 		 * We need to re-route that interrupt to its new destination.
1561 		 * First get and lock the descriptor
1562 		 */
1563 		struct irq_desc *desc = irq_to_desc(irq);
1564 		struct irq_data *d = irq_desc_get_irq_data(desc);
1565 		struct xive_irq_data *xd;
1566 
1567 		/*
1568 		 * Ignore anything that isn't a XIVE irq and ignore
1569 		 * IPIs, so can just be dropped.
1570 		 */
1571 		if (d->domain != xive_irq_domain)
1572 			continue;
1573 
1574 		/*
1575 		 * The IRQ should have already been re-routed, it's just a
1576 		 * stale in the old queue, so re-trigger it in order to make
1577 		 * it reach is new destination.
1578 		 */
1579 #ifdef DEBUG_FLUSH
1580 		pr_info("CPU %d: Got irq %d while offline, re-sending...\n",
1581 			cpu, irq);
1582 #endif
1583 		raw_spin_lock(&desc->lock);
1584 		xd = irq_desc_get_handler_data(desc);
1585 
1586 		/*
1587 		 * Clear saved_p to indicate that it's no longer pending
1588 		 */
1589 		xd->saved_p = false;
1590 
1591 		/*
1592 		 * For LSIs, we EOI, this will cause a resend if it's
1593 		 * still asserted. Otherwise do an MSI retrigger.
1594 		 */
1595 		if (xd->flags & XIVE_IRQ_FLAG_LSI)
1596 			xive_do_source_eoi(xd);
1597 		else
1598 			xive_irq_retrigger(d);
1599 
1600 		raw_spin_unlock(&desc->lock);
1601 	}
1602 }
1603 
xive_smp_disable_cpu(void)1604 void xive_smp_disable_cpu(void)
1605 {
1606 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
1607 	unsigned int cpu = smp_processor_id();
1608 
1609 	/* Migrate interrupts away from the CPU */
1610 	irq_migrate_all_off_this_cpu();
1611 
1612 	/* Set CPPR to 0 to disable flow of interrupts */
1613 	xc->cppr = 0;
1614 	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0);
1615 
1616 	/* Flush everything still in the queue */
1617 	xive_flush_cpu_queue(cpu, xc);
1618 
1619 	/* Re-enable CPPR  */
1620 	xc->cppr = 0xff;
1621 	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0xff);
1622 }
1623 
xive_flush_interrupt(void)1624 void xive_flush_interrupt(void)
1625 {
1626 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
1627 	unsigned int cpu = smp_processor_id();
1628 
1629 	/* Called if an interrupt occurs while the CPU is hot unplugged */
1630 	xive_flush_cpu_queue(cpu, xc);
1631 }
1632 
1633 #endif /* CONFIG_HOTPLUG_CPU */
1634 
1635 #endif /* CONFIG_SMP */
1636 
xive_teardown_cpu(void)1637 noinstr void xive_teardown_cpu(void)
1638 {
1639 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
1640 	unsigned int cpu = smp_processor_id();
1641 
1642 	/* Set CPPR to 0 to disable flow of interrupts */
1643 	xc->cppr = 0;
1644 	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0);
1645 
1646 	if (xive_ops->teardown_cpu)
1647 		xive_ops->teardown_cpu(cpu, xc);
1648 
1649 #ifdef CONFIG_SMP
1650 	/* Get rid of IPI */
1651 	xive_cleanup_cpu_ipi(cpu, xc);
1652 #endif
1653 
1654 	/* Disable and free the queues */
1655 	xive_cleanup_cpu_queues(cpu, xc);
1656 }
1657 
xive_shutdown(void)1658 void xive_shutdown(void)
1659 {
1660 	xive_ops->shutdown();
1661 }
1662 
xive_core_init(struct device_node * np,const struct xive_ops * ops,void __iomem * area,u32 offset,u8 max_prio)1663 bool __init xive_core_init(struct device_node *np, const struct xive_ops *ops,
1664 			   void __iomem *area, u32 offset, u8 max_prio)
1665 {
1666 	xive_tima = area;
1667 	xive_tima_offset = offset;
1668 	xive_ops = ops;
1669 	xive_irq_priority = max_prio;
1670 
1671 	ppc_md.get_irq = xive_get_irq;
1672 	__xive_enabled = true;
1673 
1674 	pr_debug("Initializing host..\n");
1675 	xive_init_host(np);
1676 
1677 	pr_debug("Initializing boot CPU..\n");
1678 
1679 	/* Allocate per-CPU data and queues */
1680 	xive_prepare_cpu(smp_processor_id());
1681 
1682 	/* Get ready for interrupts */
1683 	xive_setup_cpu();
1684 
1685 	pr_info("Interrupt handling initialized with %s backend\n",
1686 		xive_ops->name);
1687 	pr_info("Using priority %d for all interrupts\n", max_prio);
1688 
1689 	return true;
1690 }
1691 
xive_queue_page_alloc(unsigned int cpu,u32 queue_shift)1692 __be32 *xive_queue_page_alloc(unsigned int cpu, u32 queue_shift)
1693 {
1694 	unsigned int alloc_order;
1695 	struct page *pages;
1696 	__be32 *qpage;
1697 
1698 	alloc_order = xive_alloc_order(queue_shift);
1699 	pages = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, alloc_order);
1700 	if (!pages)
1701 		return ERR_PTR(-ENOMEM);
1702 	qpage = (__be32 *)page_address(pages);
1703 	memset(qpage, 0, 1 << queue_shift);
1704 
1705 	return qpage;
1706 }
1707 
xive_off(char * arg)1708 static int __init xive_off(char *arg)
1709 {
1710 	xive_cmdline_disabled = true;
1711 	return 1;
1712 }
1713 __setup("xive=off", xive_off);
1714 
xive_store_eoi_cmdline(char * arg)1715 static int __init xive_store_eoi_cmdline(char *arg)
1716 {
1717 	if (!arg)
1718 		return 1;
1719 
1720 	if (strncmp(arg, "off", 3) == 0) {
1721 		pr_info("StoreEOI disabled on kernel command line\n");
1722 		xive_store_eoi = false;
1723 	}
1724 	return 1;
1725 }
1726 __setup("xive.store-eoi=", xive_store_eoi_cmdline);
1727 
1728 #ifdef CONFIG_DEBUG_FS
xive_debug_show_ipi(struct seq_file * m,int cpu)1729 static void xive_debug_show_ipi(struct seq_file *m, int cpu)
1730 {
1731 	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
1732 
1733 	seq_printf(m, "CPU %d: ", cpu);
1734 	if (xc) {
1735 		seq_printf(m, "pp=%02x CPPR=%02x ", xc->pending_prio, xc->cppr);
1736 
1737 #ifdef CONFIG_SMP
1738 		{
1739 			char buffer[128];
1740 
1741 			xive_irq_data_dump(&xc->ipi_data, buffer, sizeof(buffer));
1742 			seq_printf(m, "IPI=0x%08x %s", xc->hw_ipi, buffer);
1743 		}
1744 #endif
1745 	}
1746 	seq_puts(m, "\n");
1747 }
1748 
xive_debug_show_irq(struct seq_file * m,struct irq_data * d)1749 static void xive_debug_show_irq(struct seq_file *m, struct irq_data *d)
1750 {
1751 	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
1752 	int rc;
1753 	u32 target;
1754 	u8 prio;
1755 	u32 lirq;
1756 	char buffer[128];
1757 
1758 	rc = xive_ops->get_irq_config(hw_irq, &target, &prio, &lirq);
1759 	if (rc) {
1760 		seq_printf(m, "IRQ 0x%08x : no config rc=%d\n", hw_irq, rc);
1761 		return;
1762 	}
1763 
1764 	seq_printf(m, "IRQ 0x%08x : target=0x%x prio=%02x lirq=0x%x ",
1765 		   hw_irq, target, prio, lirq);
1766 
1767 	xive_irq_data_dump(irq_data_get_irq_handler_data(d), buffer, sizeof(buffer));
1768 	seq_puts(m, buffer);
1769 	seq_puts(m, "\n");
1770 }
1771 
xive_irq_debug_show(struct seq_file * m,void * private)1772 static int xive_irq_debug_show(struct seq_file *m, void *private)
1773 {
1774 	unsigned int i;
1775 	struct irq_desc *desc;
1776 
1777 	for_each_irq_desc(i, desc) {
1778 		struct irq_data *d = irq_domain_get_irq_data(xive_irq_domain, i);
1779 
1780 		if (d)
1781 			xive_debug_show_irq(m, d);
1782 	}
1783 	return 0;
1784 }
1785 DEFINE_SHOW_ATTRIBUTE(xive_irq_debug);
1786 
xive_ipi_debug_show(struct seq_file * m,void * private)1787 static int xive_ipi_debug_show(struct seq_file *m, void *private)
1788 {
1789 	int cpu;
1790 
1791 	if (xive_ops->debug_show)
1792 		xive_ops->debug_show(m, private);
1793 
1794 	for_each_online_cpu(cpu)
1795 		xive_debug_show_ipi(m, cpu);
1796 	return 0;
1797 }
1798 DEFINE_SHOW_ATTRIBUTE(xive_ipi_debug);
1799 
xive_eq_debug_show_one(struct seq_file * m,struct xive_q * q,u8 prio)1800 static void xive_eq_debug_show_one(struct seq_file *m, struct xive_q *q, u8 prio)
1801 {
1802 	int i;
1803 
1804 	seq_printf(m, "EQ%d idx=%d T=%d\n", prio, q->idx, q->toggle);
1805 	if (q->qpage) {
1806 		for (i = 0; i < q->msk + 1; i++) {
1807 			if (!(i % 8))
1808 				seq_printf(m, "%05d ", i);
1809 			seq_printf(m, "%08x%s", be32_to_cpup(q->qpage + i),
1810 				   (i + 1) % 8 ? " " : "\n");
1811 		}
1812 	}
1813 	seq_puts(m, "\n");
1814 }
1815 
xive_eq_debug_show(struct seq_file * m,void * private)1816 static int xive_eq_debug_show(struct seq_file *m, void *private)
1817 {
1818 	int cpu = (long)m->private;
1819 	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
1820 
1821 	if (xc)
1822 		xive_eq_debug_show_one(m, &xc->queue[xive_irq_priority],
1823 				       xive_irq_priority);
1824 	return 0;
1825 }
1826 DEFINE_SHOW_ATTRIBUTE(xive_eq_debug);
1827 
xive_core_debugfs_create(void)1828 static void xive_core_debugfs_create(void)
1829 {
1830 	struct dentry *xive_dir;
1831 	struct dentry *xive_eq_dir;
1832 	long cpu;
1833 	char name[16];
1834 
1835 	xive_dir = debugfs_create_dir("xive", arch_debugfs_dir);
1836 	if (IS_ERR(xive_dir))
1837 		return;
1838 
1839 	debugfs_create_file("ipis", 0400, xive_dir,
1840 			    NULL, &xive_ipi_debug_fops);
1841 	debugfs_create_file("interrupts", 0400, xive_dir,
1842 			    NULL, &xive_irq_debug_fops);
1843 	xive_eq_dir = debugfs_create_dir("eqs", xive_dir);
1844 	for_each_possible_cpu(cpu) {
1845 		snprintf(name, sizeof(name), "cpu%ld", cpu);
1846 		debugfs_create_file(name, 0400, xive_eq_dir, (void *)cpu,
1847 				    &xive_eq_debug_fops);
1848 	}
1849 	debugfs_create_bool("store-eoi", 0600, xive_dir, &xive_store_eoi);
1850 
1851 	if (xive_ops->debug_create)
1852 		xive_ops->debug_create(xive_dir);
1853 }
1854 #else
xive_core_debugfs_create(void)1855 static inline void xive_core_debugfs_create(void) { }
1856 #endif /* CONFIG_DEBUG_FS */
1857 
xive_core_debug_init(void)1858 int xive_core_debug_init(void)
1859 {
1860 	if (xive_enabled() && IS_ENABLED(CONFIG_DEBUG_FS))
1861 		xive_core_debugfs_create();
1862 
1863 	return 0;
1864 }
1865