xref: /linux/drivers/irqchip/irq-mips-gic.c (revision 0b29600a304c0c5da17ce1a7fab7cafb0eaf71f5)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2008 Ralf Baechle (ralf@linux-mips.org)
7  * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
8  */
9 
10 #define pr_fmt(fmt) "irq-mips-gic: " fmt
11 
12 #include <linux/bitfield.h>
13 #include <linux/bitmap.h>
14 #include <linux/clocksource.h>
15 #include <linux/cpuhotplug.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/irq.h>
19 #include <linux/irqchip.h>
20 #include <linux/irqdomain.h>
21 #include <linux/of_address.h>
22 #include <linux/percpu.h>
23 #include <linux/sched.h>
24 #include <linux/smp.h>
25 
26 #include <asm/mips-cps.h>
27 #include <asm/setup.h>
28 #include <asm/traps.h>
29 
30 #include <dt-bindings/interrupt-controller/mips-gic.h>
31 
32 #define GIC_MAX_INTRS		256
33 #define GIC_MAX_LONGS		BITS_TO_LONGS(GIC_MAX_INTRS)
34 
35 /* Add 2 to convert GIC CPU pin to core interrupt */
36 #define GIC_CPU_PIN_OFFSET	2
37 
38 /* Mapped interrupt to pin X, then GIC will generate the vector (X+1). */
39 #define GIC_PIN_TO_VEC_OFFSET	1
40 
41 /* Convert between local/shared IRQ number and GIC HW IRQ number. */
42 #define GIC_LOCAL_HWIRQ_BASE	0
43 #define GIC_LOCAL_TO_HWIRQ(x)	(GIC_LOCAL_HWIRQ_BASE + (x))
44 #define GIC_HWIRQ_TO_LOCAL(x)	((x) - GIC_LOCAL_HWIRQ_BASE)
45 #define GIC_SHARED_HWIRQ_BASE	GIC_NUM_LOCAL_INTRS
46 #define GIC_SHARED_TO_HWIRQ(x)	(GIC_SHARED_HWIRQ_BASE + (x))
47 #define GIC_HWIRQ_TO_SHARED(x)	((x) - GIC_SHARED_HWIRQ_BASE)
48 
49 void __iomem *mips_gic_base;
50 
51 static DEFINE_PER_CPU_READ_MOSTLY(unsigned long[GIC_MAX_LONGS], pcpu_masks);
52 
53 static DEFINE_RAW_SPINLOCK(gic_lock);
54 static struct irq_domain *gic_irq_domain;
55 static int gic_shared_intrs;
56 static unsigned int gic_cpu_pin;
57 static struct irq_chip gic_level_irq_controller, gic_edge_irq_controller;
58 
59 #ifdef CONFIG_GENERIC_IRQ_IPI
60 static DECLARE_BITMAP(ipi_resrv, GIC_MAX_INTRS);
61 static DECLARE_BITMAP(ipi_available, GIC_MAX_INTRS);
62 #endif /* CONFIG_GENERIC_IRQ_IPI */
63 
64 static struct gic_all_vpes_chip_data {
65 	u32	map;
66 	bool	mask;
67 } gic_all_vpes_chip_data[GIC_NUM_LOCAL_INTRS];
68 
__gic_with_next_online_cpu(int prev)69 static int __gic_with_next_online_cpu(int prev)
70 {
71 	unsigned int cpu;
72 
73 	/* Discover the next online CPU */
74 	cpu = cpumask_next(prev, cpu_online_mask);
75 
76 	/* If there isn't one, we're done */
77 	if (cpu >= nr_cpu_ids)
78 		return cpu;
79 
80 	/*
81 	 * Move the access lock to the next CPU's GIC local register block.
82 	 *
83 	 * Set GIC_VL_OTHER. Since the caller holds gic_lock nothing can
84 	 * clobber the written value.
85 	 */
86 	write_gic_vl_other(mips_cm_vp_id(cpu));
87 
88 	return cpu;
89 }
90 
gic_unlock_cluster(void)91 static inline void gic_unlock_cluster(void)
92 {
93 	if (mips_cps_multicluster_cpus())
94 		mips_cm_unlock_other();
95 }
96 
97 /**
98  * for_each_online_cpu_gic() - Iterate over online CPUs, access local registers
99  * @cpu: An integer variable to hold the current CPU number
100  * @gic_lock: A pointer to raw spin lock used as a guard
101  *
102  * Iterate over online CPUs & configure the other/redirect register region to
103  * access each CPUs GIC local register block, which can be accessed from the
104  * loop body using read_gic_vo_*() or write_gic_vo_*() accessor functions or
105  * their derivatives.
106  */
107 #define for_each_online_cpu_gic(cpu, gic_lock)		\
108 	guard(raw_spinlock_irqsave)(gic_lock);		\
109 	for ((cpu) = __gic_with_next_online_cpu(-1);	\
110 	     (cpu) < nr_cpu_ids;			\
111 	     gic_unlock_cluster(),			\
112 	     (cpu) = __gic_with_next_online_cpu(cpu))
113 
114 /**
115  * gic_irq_lock_cluster() - Lock redirect block access to IRQ's cluster
116  * @d: struct irq_data corresponding to the interrupt we're interested in
117  *
118  * Locks redirect register block access to the global register block of the GIC
119  * within the remote cluster that the IRQ corresponding to @d is affine to,
120  * returning true when this redirect block setup & locking has been performed.
121  *
122  * If @d is affine to the local cluster then no locking is performed and this
123  * function will return false, indicating to the caller that it should access
124  * the local clusters registers without the overhead of indirection through the
125  * redirect block.
126  *
127  * In summary, if this function returns true then the caller should access GIC
128  * registers using redirect register block accessors & then call
129  * mips_cm_unlock_other() when done. If this function returns false then the
130  * caller should trivially access GIC registers in the local cluster.
131  *
132  * Returns true if locking performed, else false.
133  */
gic_irq_lock_cluster(struct irq_data * d)134 static bool gic_irq_lock_cluster(struct irq_data *d)
135 {
136 	unsigned int cpu, cl;
137 
138 	cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
139 	BUG_ON(cpu >= NR_CPUS);
140 
141 	cl = cpu_cluster(&cpu_data[cpu]);
142 	if (cl == cpu_cluster(&current_cpu_data))
143 		return false;
144 	if (mips_cps_numcores(cl) == 0)
145 		return false;
146 	mips_cm_lock_other(cl, 0, 0, CM_GCR_Cx_OTHER_BLOCK_GLOBAL);
147 	return true;
148 }
149 
gic_clear_pcpu_masks(unsigned int intr)150 static void gic_clear_pcpu_masks(unsigned int intr)
151 {
152 	unsigned int i;
153 
154 	/* Clear the interrupt's bit in all pcpu_masks */
155 	for_each_possible_cpu(i)
156 		clear_bit(intr, per_cpu_ptr(pcpu_masks, i));
157 }
158 
gic_local_irq_is_routable(int intr)159 static bool gic_local_irq_is_routable(int intr)
160 {
161 	u32 vpe_ctl;
162 
163 	/* All local interrupts are routable in EIC mode. */
164 	if (cpu_has_veic)
165 		return true;
166 
167 	vpe_ctl = read_gic_vl_ctl();
168 	switch (intr) {
169 	case GIC_LOCAL_INT_TIMER:
170 		return vpe_ctl & GIC_VX_CTL_TIMER_ROUTABLE;
171 	case GIC_LOCAL_INT_PERFCTR:
172 		return vpe_ctl & GIC_VX_CTL_PERFCNT_ROUTABLE;
173 	case GIC_LOCAL_INT_FDC:
174 		return vpe_ctl & GIC_VX_CTL_FDC_ROUTABLE;
175 	case GIC_LOCAL_INT_SWINT0:
176 	case GIC_LOCAL_INT_SWINT1:
177 		return vpe_ctl & GIC_VX_CTL_SWINT_ROUTABLE;
178 	default:
179 		return true;
180 	}
181 }
182 
gic_bind_eic_interrupt(int irq,int set)183 static void gic_bind_eic_interrupt(int irq, int set)
184 {
185 	/* Convert irq vector # to hw int # */
186 	irq -= GIC_PIN_TO_VEC_OFFSET;
187 
188 	/* Set irq to use shadow set */
189 	write_gic_vl_eic_shadow_set(irq, set);
190 }
191 
gic_send_ipi(struct irq_data * d,unsigned int cpu)192 static void gic_send_ipi(struct irq_data *d, unsigned int cpu)
193 {
194 	irq_hw_number_t hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(d));
195 
196 	if (gic_irq_lock_cluster(d)) {
197 		write_gic_redir_wedge(GIC_WEDGE_RW | hwirq);
198 		mips_cm_unlock_other();
199 	} else {
200 		write_gic_wedge(GIC_WEDGE_RW | hwirq);
201 	}
202 }
203 
gic_get_c0_compare_int(void)204 int gic_get_c0_compare_int(void)
205 {
206 	if (!gic_local_irq_is_routable(GIC_LOCAL_INT_TIMER))
207 		return MIPS_CPU_IRQ_BASE + cp0_compare_irq;
208 	return irq_create_mapping(gic_irq_domain,
209 				  GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_TIMER));
210 }
211 
gic_get_c0_perfcount_int(void)212 int gic_get_c0_perfcount_int(void)
213 {
214 	if (!gic_local_irq_is_routable(GIC_LOCAL_INT_PERFCTR)) {
215 		/* Is the performance counter shared with the timer? */
216 		if (cp0_perfcount_irq < 0)
217 			return -1;
218 		return MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
219 	}
220 	return irq_create_mapping(gic_irq_domain,
221 				  GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_PERFCTR));
222 }
223 
gic_get_c0_fdc_int(void)224 int gic_get_c0_fdc_int(void)
225 {
226 	if (!gic_local_irq_is_routable(GIC_LOCAL_INT_FDC)) {
227 		/* Is the FDC IRQ even present? */
228 		if (cp0_fdc_irq < 0)
229 			return -1;
230 		return MIPS_CPU_IRQ_BASE + cp0_fdc_irq;
231 	}
232 
233 	return irq_create_mapping(gic_irq_domain,
234 				  GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_FDC));
235 }
236 
gic_handle_shared_int(bool chained)237 static void gic_handle_shared_int(bool chained)
238 {
239 	unsigned int intr;
240 	unsigned long *pcpu_mask;
241 	DECLARE_BITMAP(pending, GIC_MAX_INTRS);
242 
243 	/* Get per-cpu bitmaps */
244 	pcpu_mask = this_cpu_ptr(pcpu_masks);
245 
246 	if (mips_cm_is64)
247 		__ioread64_copy(pending, addr_gic_pend(),
248 				DIV_ROUND_UP(gic_shared_intrs, 64));
249 	else
250 		__ioread32_copy(pending, addr_gic_pend(),
251 				DIV_ROUND_UP(gic_shared_intrs, 32));
252 
253 	bitmap_and(pending, pending, pcpu_mask, gic_shared_intrs);
254 
255 	for_each_set_bit(intr, pending, gic_shared_intrs) {
256 		if (chained)
257 			generic_handle_domain_irq(gic_irq_domain,
258 						  GIC_SHARED_TO_HWIRQ(intr));
259 		else
260 			do_domain_IRQ(gic_irq_domain,
261 				      GIC_SHARED_TO_HWIRQ(intr));
262 	}
263 }
264 
gic_mask_irq(struct irq_data * d)265 static void gic_mask_irq(struct irq_data *d)
266 {
267 	unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
268 
269 	if (gic_irq_lock_cluster(d)) {
270 		write_gic_redir_rmask(intr);
271 		mips_cm_unlock_other();
272 	} else {
273 		write_gic_rmask(intr);
274 	}
275 
276 	gic_clear_pcpu_masks(intr);
277 }
278 
gic_unmask_irq(struct irq_data * d)279 static void gic_unmask_irq(struct irq_data *d)
280 {
281 	unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
282 	unsigned int cpu;
283 
284 	if (gic_irq_lock_cluster(d)) {
285 		write_gic_redir_smask(intr);
286 		mips_cm_unlock_other();
287 	} else {
288 		write_gic_smask(intr);
289 	}
290 
291 	gic_clear_pcpu_masks(intr);
292 	cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
293 	set_bit(intr, per_cpu_ptr(pcpu_masks, cpu));
294 }
295 
gic_ack_irq(struct irq_data * d)296 static void gic_ack_irq(struct irq_data *d)
297 {
298 	unsigned int irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
299 
300 	if (gic_irq_lock_cluster(d)) {
301 		write_gic_redir_wedge(irq);
302 		mips_cm_unlock_other();
303 	} else {
304 		write_gic_wedge(irq);
305 	}
306 }
307 
gic_set_type(struct irq_data * d,unsigned int type)308 static int gic_set_type(struct irq_data *d, unsigned int type)
309 {
310 	unsigned int irq, pol, trig, dual;
311 	unsigned long flags;
312 
313 	irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
314 
315 	raw_spin_lock_irqsave(&gic_lock, flags);
316 	switch (type & IRQ_TYPE_SENSE_MASK) {
317 	case IRQ_TYPE_EDGE_FALLING:
318 		pol = GIC_POL_FALLING_EDGE;
319 		trig = GIC_TRIG_EDGE;
320 		dual = GIC_DUAL_SINGLE;
321 		break;
322 	case IRQ_TYPE_EDGE_RISING:
323 		pol = GIC_POL_RISING_EDGE;
324 		trig = GIC_TRIG_EDGE;
325 		dual = GIC_DUAL_SINGLE;
326 		break;
327 	case IRQ_TYPE_EDGE_BOTH:
328 		pol = 0; /* Doesn't matter */
329 		trig = GIC_TRIG_EDGE;
330 		dual = GIC_DUAL_DUAL;
331 		break;
332 	case IRQ_TYPE_LEVEL_LOW:
333 		pol = GIC_POL_ACTIVE_LOW;
334 		trig = GIC_TRIG_LEVEL;
335 		dual = GIC_DUAL_SINGLE;
336 		break;
337 	case IRQ_TYPE_LEVEL_HIGH:
338 	default:
339 		pol = GIC_POL_ACTIVE_HIGH;
340 		trig = GIC_TRIG_LEVEL;
341 		dual = GIC_DUAL_SINGLE;
342 		break;
343 	}
344 
345 	if (gic_irq_lock_cluster(d)) {
346 		change_gic_redir_pol(irq, pol);
347 		change_gic_redir_trig(irq, trig);
348 		change_gic_redir_dual(irq, dual);
349 		mips_cm_unlock_other();
350 	} else {
351 		change_gic_pol(irq, pol);
352 		change_gic_trig(irq, trig);
353 		change_gic_dual(irq, dual);
354 	}
355 
356 	if (trig == GIC_TRIG_EDGE)
357 		irq_set_chip_handler_name_locked(d, &gic_edge_irq_controller,
358 						 handle_edge_irq, NULL);
359 	else
360 		irq_set_chip_handler_name_locked(d, &gic_level_irq_controller,
361 						 handle_level_irq, NULL);
362 	raw_spin_unlock_irqrestore(&gic_lock, flags);
363 
364 	return 0;
365 }
366 
367 #ifdef CONFIG_SMP
gic_set_affinity(struct irq_data * d,const struct cpumask * cpumask,bool force)368 static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
369 			    bool force)
370 {
371 	unsigned int irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
372 	unsigned int cpu, cl, old_cpu, old_cl;
373 	unsigned long flags;
374 
375 	/*
376 	 * The GIC specifies that we can only route an interrupt to one VP(E),
377 	 * ie. CPU in Linux parlance, at a time. Therefore we always route to
378 	 * the first forced or online CPU in the mask.
379 	 */
380 	if (force)
381 		cpu = cpumask_first(cpumask);
382 	else
383 		cpu = cpumask_first_and(cpumask, cpu_online_mask);
384 
385 	if (cpu >= NR_CPUS)
386 		return -EINVAL;
387 
388 	old_cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
389 	old_cl = cpu_cluster(&cpu_data[old_cpu]);
390 	cl = cpu_cluster(&cpu_data[cpu]);
391 
392 	raw_spin_lock_irqsave(&gic_lock, flags);
393 
394 	/*
395 	 * If we're moving affinity between clusters, stop routing the
396 	 * interrupt to any VP(E) in the old cluster.
397 	 */
398 	if (cl != old_cl) {
399 		if (gic_irq_lock_cluster(d)) {
400 			write_gic_redir_map_vp(irq, 0);
401 			mips_cm_unlock_other();
402 		} else {
403 			write_gic_map_vp(irq, 0);
404 		}
405 	}
406 
407 	/*
408 	 * Update effective affinity - after this gic_irq_lock_cluster() will
409 	 * begin operating on the new cluster.
410 	 */
411 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
412 
413 	/*
414 	 * If we're moving affinity between clusters, configure the interrupt
415 	 * trigger type in the new cluster.
416 	 */
417 	if (cl != old_cl)
418 		gic_set_type(d, irqd_get_trigger_type(d));
419 
420 	/* Route the interrupt to its new VP(E) */
421 	if (gic_irq_lock_cluster(d)) {
422 		write_gic_redir_map_pin(irq,
423 					GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin);
424 		write_gic_redir_map_vp(irq, BIT(mips_cm_vp_id(cpu)));
425 
426 		/* Update the pcpu_masks */
427 		gic_clear_pcpu_masks(irq);
428 		if (read_gic_redir_mask(irq))
429 			set_bit(irq, per_cpu_ptr(pcpu_masks, cpu));
430 
431 		mips_cm_unlock_other();
432 	} else {
433 		write_gic_map_pin(irq, GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin);
434 		write_gic_map_vp(irq, BIT(mips_cm_vp_id(cpu)));
435 
436 		/* Update the pcpu_masks */
437 		gic_clear_pcpu_masks(irq);
438 		if (read_gic_mask(irq))
439 			set_bit(irq, per_cpu_ptr(pcpu_masks, cpu));
440 	}
441 
442 	raw_spin_unlock_irqrestore(&gic_lock, flags);
443 
444 	return IRQ_SET_MASK_OK;
445 }
446 #endif
447 
448 static struct irq_chip gic_level_irq_controller = {
449 	.name			=	"MIPS GIC",
450 	.irq_mask		=	gic_mask_irq,
451 	.irq_unmask		=	gic_unmask_irq,
452 	.irq_set_type		=	gic_set_type,
453 #ifdef CONFIG_SMP
454 	.irq_set_affinity	=	gic_set_affinity,
455 #endif
456 };
457 
458 static struct irq_chip gic_edge_irq_controller = {
459 	.name			=	"MIPS GIC",
460 	.irq_ack		=	gic_ack_irq,
461 	.irq_mask		=	gic_mask_irq,
462 	.irq_unmask		=	gic_unmask_irq,
463 	.irq_set_type		=	gic_set_type,
464 #ifdef CONFIG_SMP
465 	.irq_set_affinity	=	gic_set_affinity,
466 #endif
467 	.ipi_send_single	=	gic_send_ipi,
468 };
469 
gic_handle_local_int(bool chained)470 static void gic_handle_local_int(bool chained)
471 {
472 	unsigned long pending, masked;
473 	unsigned int intr;
474 
475 	pending = read_gic_vl_pend();
476 	masked = read_gic_vl_mask();
477 
478 	bitmap_and(&pending, &pending, &masked, GIC_NUM_LOCAL_INTRS);
479 
480 	for_each_set_bit(intr, &pending, GIC_NUM_LOCAL_INTRS) {
481 		if (chained)
482 			generic_handle_domain_irq(gic_irq_domain,
483 						  GIC_LOCAL_TO_HWIRQ(intr));
484 		else
485 			do_domain_IRQ(gic_irq_domain,
486 				      GIC_LOCAL_TO_HWIRQ(intr));
487 	}
488 }
489 
gic_mask_local_irq(struct irq_data * d)490 static void gic_mask_local_irq(struct irq_data *d)
491 {
492 	int intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
493 
494 	write_gic_vl_rmask(BIT(intr));
495 }
496 
gic_unmask_local_irq(struct irq_data * d)497 static void gic_unmask_local_irq(struct irq_data *d)
498 {
499 	int intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
500 
501 	write_gic_vl_smask(BIT(intr));
502 }
503 
504 static struct irq_chip gic_local_irq_controller = {
505 	.name			=	"MIPS GIC Local",
506 	.irq_mask		=	gic_mask_local_irq,
507 	.irq_unmask		=	gic_unmask_local_irq,
508 };
509 
gic_mask_local_irq_all_vpes(struct irq_data * d)510 static void gic_mask_local_irq_all_vpes(struct irq_data *d)
511 {
512 	struct gic_all_vpes_chip_data *cd;
513 	int intr, cpu;
514 
515 	if (!mips_cps_multicluster_cpus())
516 		return;
517 
518 	intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
519 	cd = irq_data_get_irq_chip_data(d);
520 	cd->mask = false;
521 
522 	for_each_online_cpu_gic(cpu, &gic_lock)
523 		write_gic_vo_rmask(BIT(intr));
524 }
525 
gic_unmask_local_irq_all_vpes(struct irq_data * d)526 static void gic_unmask_local_irq_all_vpes(struct irq_data *d)
527 {
528 	struct gic_all_vpes_chip_data *cd;
529 	int intr, cpu;
530 
531 	if (!mips_cps_multicluster_cpus())
532 		return;
533 
534 	intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
535 	cd = irq_data_get_irq_chip_data(d);
536 	cd->mask = true;
537 
538 	for_each_online_cpu_gic(cpu, &gic_lock)
539 		write_gic_vo_smask(BIT(intr));
540 }
541 
gic_all_vpes_irq_cpu_online(void)542 static void gic_all_vpes_irq_cpu_online(void)
543 {
544 	static const unsigned int local_intrs[] = {
545 		GIC_LOCAL_INT_TIMER,
546 		GIC_LOCAL_INT_PERFCTR,
547 		GIC_LOCAL_INT_FDC,
548 	};
549 	unsigned long flags;
550 	int i;
551 
552 	raw_spin_lock_irqsave(&gic_lock, flags);
553 
554 	for (i = 0; i < ARRAY_SIZE(local_intrs); i++) {
555 		unsigned int intr = local_intrs[i];
556 		struct gic_all_vpes_chip_data *cd;
557 
558 		if (!gic_local_irq_is_routable(intr))
559 			continue;
560 		cd = &gic_all_vpes_chip_data[intr];
561 		write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
562 		if (cd->mask)
563 			write_gic_vl_smask(BIT(intr));
564 	}
565 
566 	raw_spin_unlock_irqrestore(&gic_lock, flags);
567 }
568 
569 static struct irq_chip gic_all_vpes_local_irq_controller = {
570 	.name			= "MIPS GIC Local",
571 	.irq_mask		= gic_mask_local_irq_all_vpes,
572 	.irq_unmask		= gic_unmask_local_irq_all_vpes,
573 };
574 
__gic_irq_dispatch(void)575 static void __gic_irq_dispatch(void)
576 {
577 	gic_handle_local_int(false);
578 	gic_handle_shared_int(false);
579 }
580 
gic_irq_dispatch(struct irq_desc * desc)581 static void gic_irq_dispatch(struct irq_desc *desc)
582 {
583 	gic_handle_local_int(true);
584 	gic_handle_shared_int(true);
585 }
586 
gic_shared_irq_domain_map(struct irq_domain * d,unsigned int virq,irq_hw_number_t hw,unsigned int cpu)587 static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
588 				     irq_hw_number_t hw, unsigned int cpu)
589 {
590 	int intr = GIC_HWIRQ_TO_SHARED(hw);
591 	struct irq_data *data;
592 	unsigned long flags;
593 
594 	data = irq_get_irq_data(virq);
595 	irq_data_update_effective_affinity(data, cpumask_of(cpu));
596 
597 	raw_spin_lock_irqsave(&gic_lock, flags);
598 
599 	/* Route the interrupt to its VP(E) */
600 	if (gic_irq_lock_cluster(data)) {
601 		write_gic_redir_map_pin(intr,
602 					GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin);
603 		write_gic_redir_map_vp(intr, BIT(mips_cm_vp_id(cpu)));
604 		mips_cm_unlock_other();
605 	} else {
606 		write_gic_map_pin(intr, GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin);
607 		write_gic_map_vp(intr, BIT(mips_cm_vp_id(cpu)));
608 	}
609 
610 	raw_spin_unlock_irqrestore(&gic_lock, flags);
611 
612 	return 0;
613 }
614 
gic_irq_domain_xlate(struct irq_domain * d,struct device_node * ctrlr,const u32 * intspec,unsigned int intsize,irq_hw_number_t * out_hwirq,unsigned int * out_type)615 static int gic_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
616 				const u32 *intspec, unsigned int intsize,
617 				irq_hw_number_t *out_hwirq,
618 				unsigned int *out_type)
619 {
620 	if (intsize != 3)
621 		return -EINVAL;
622 
623 	if (intspec[0] == GIC_SHARED)
624 		*out_hwirq = GIC_SHARED_TO_HWIRQ(intspec[1]);
625 	else if (intspec[0] == GIC_LOCAL)
626 		*out_hwirq = GIC_LOCAL_TO_HWIRQ(intspec[1]);
627 	else
628 		return -EINVAL;
629 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
630 
631 	return 0;
632 }
633 
gic_irq_domain_map(struct irq_domain * d,unsigned int virq,irq_hw_number_t hwirq)634 static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
635 			      irq_hw_number_t hwirq)
636 {
637 	struct gic_all_vpes_chip_data *cd;
638 	unsigned int intr;
639 	int err, cpu;
640 	u32 map;
641 
642 	if (hwirq >= GIC_SHARED_HWIRQ_BASE) {
643 #ifdef CONFIG_GENERIC_IRQ_IPI
644 		/* verify that shared irqs don't conflict with an IPI irq */
645 		if (test_bit(GIC_HWIRQ_TO_SHARED(hwirq), ipi_resrv))
646 			return -EBUSY;
647 #endif /* CONFIG_GENERIC_IRQ_IPI */
648 
649 		err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
650 						    &gic_level_irq_controller,
651 						    NULL);
652 		if (err)
653 			return err;
654 
655 		irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
656 		return gic_shared_irq_domain_map(d, virq, hwirq, 0);
657 	}
658 
659 	intr = GIC_HWIRQ_TO_LOCAL(hwirq);
660 	map = GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin;
661 
662 	/*
663 	 * If adding support for more per-cpu interrupts, keep the
664 	 * array in gic_all_vpes_irq_cpu_online() in sync.
665 	 */
666 	switch (intr) {
667 	case GIC_LOCAL_INT_TIMER:
668 	case GIC_LOCAL_INT_PERFCTR:
669 	case GIC_LOCAL_INT_FDC:
670 		/*
671 		 * HACK: These are all really percpu interrupts, but
672 		 * the rest of the MIPS kernel code does not use the
673 		 * percpu IRQ API for them.
674 		 */
675 		cd = &gic_all_vpes_chip_data[intr];
676 		cd->map = map;
677 		err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
678 						    &gic_all_vpes_local_irq_controller,
679 						    cd);
680 		if (err)
681 			return err;
682 
683 		irq_set_handler(virq, handle_percpu_irq);
684 		break;
685 
686 	default:
687 		err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
688 						    &gic_local_irq_controller,
689 						    NULL);
690 		if (err)
691 			return err;
692 
693 		irq_set_handler(virq, handle_percpu_devid_irq);
694 		irq_set_percpu_devid(virq);
695 		break;
696 	}
697 
698 	if (!gic_local_irq_is_routable(intr))
699 		return -EPERM;
700 
701 	if (mips_cps_multicluster_cpus()) {
702 		for_each_online_cpu_gic(cpu, &gic_lock)
703 			write_gic_vo_map(mips_gic_vx_map_reg(intr), map);
704 	}
705 
706 	return 0;
707 }
708 
gic_irq_domain_alloc(struct irq_domain * d,unsigned int virq,unsigned int nr_irqs,void * arg)709 static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
710 				unsigned int nr_irqs, void *arg)
711 {
712 	struct irq_fwspec *fwspec = arg;
713 	irq_hw_number_t hwirq;
714 
715 	if (fwspec->param[0] == GIC_SHARED)
716 		hwirq = GIC_SHARED_TO_HWIRQ(fwspec->param[1]);
717 	else
718 		hwirq = GIC_LOCAL_TO_HWIRQ(fwspec->param[1]);
719 
720 	return gic_irq_domain_map(d, virq, hwirq);
721 }
722 
gic_irq_domain_free(struct irq_domain * d,unsigned int virq,unsigned int nr_irqs)723 static void gic_irq_domain_free(struct irq_domain *d, unsigned int virq,
724 			 unsigned int nr_irqs)
725 {
726 }
727 
728 static const struct irq_domain_ops gic_irq_domain_ops = {
729 	.xlate = gic_irq_domain_xlate,
730 	.alloc = gic_irq_domain_alloc,
731 	.free = gic_irq_domain_free,
732 	.map = gic_irq_domain_map,
733 };
734 
735 #ifdef CONFIG_GENERIC_IRQ_IPI
736 
gic_ipi_domain_xlate(struct irq_domain * d,struct device_node * ctrlr,const u32 * intspec,unsigned int intsize,irq_hw_number_t * out_hwirq,unsigned int * out_type)737 static int gic_ipi_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
738 				const u32 *intspec, unsigned int intsize,
739 				irq_hw_number_t *out_hwirq,
740 				unsigned int *out_type)
741 {
742 	/*
743 	 * There's nothing to translate here. hwirq is dynamically allocated and
744 	 * the irq type is always edge triggered.
745 	 * */
746 	*out_hwirq = 0;
747 	*out_type = IRQ_TYPE_EDGE_RISING;
748 
749 	return 0;
750 }
751 
gic_ipi_domain_alloc(struct irq_domain * d,unsigned int virq,unsigned int nr_irqs,void * arg)752 static int gic_ipi_domain_alloc(struct irq_domain *d, unsigned int virq,
753 				unsigned int nr_irqs, void *arg)
754 {
755 	struct cpumask *ipimask = arg;
756 	irq_hw_number_t hwirq, base_hwirq;
757 	int cpu, ret, i;
758 
759 	base_hwirq = find_first_bit(ipi_available, gic_shared_intrs);
760 	if (base_hwirq == gic_shared_intrs)
761 		return -ENOMEM;
762 
763 	/* check that we have enough space */
764 	for (i = base_hwirq; i < nr_irqs; i++) {
765 		if (!test_bit(i, ipi_available))
766 			return -EBUSY;
767 	}
768 	bitmap_clear(ipi_available, base_hwirq, nr_irqs);
769 
770 	/* map the hwirq for each cpu consecutively */
771 	i = 0;
772 	for_each_cpu(cpu, ipimask) {
773 		hwirq = GIC_SHARED_TO_HWIRQ(base_hwirq + i);
774 
775 		ret = irq_domain_set_hwirq_and_chip(d, virq + i, hwirq,
776 						    &gic_edge_irq_controller,
777 						    NULL);
778 		if (ret)
779 			goto error;
780 
781 		ret = irq_domain_set_hwirq_and_chip(d->parent, virq + i, hwirq,
782 						    &gic_edge_irq_controller,
783 						    NULL);
784 		if (ret)
785 			goto error;
786 
787 		/* Set affinity to cpu.  */
788 		irq_data_update_effective_affinity(irq_get_irq_data(virq + i),
789 						   cpumask_of(cpu));
790 		ret = irq_set_irq_type(virq + i, IRQ_TYPE_EDGE_RISING);
791 		if (ret)
792 			goto error;
793 
794 		ret = gic_shared_irq_domain_map(d, virq + i, hwirq, cpu);
795 		if (ret)
796 			goto error;
797 
798 		i++;
799 	}
800 
801 	return 0;
802 error:
803 	bitmap_set(ipi_available, base_hwirq, nr_irqs);
804 	return ret;
805 }
806 
gic_ipi_domain_free(struct irq_domain * d,unsigned int virq,unsigned int nr_irqs)807 static void gic_ipi_domain_free(struct irq_domain *d, unsigned int virq,
808 				unsigned int nr_irqs)
809 {
810 	irq_hw_number_t base_hwirq;
811 	struct irq_data *data;
812 
813 	data = irq_get_irq_data(virq);
814 	if (!data)
815 		return;
816 
817 	base_hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(data));
818 	bitmap_set(ipi_available, base_hwirq, nr_irqs);
819 }
820 
gic_ipi_domain_match(struct irq_domain * d,struct device_node * node,enum irq_domain_bus_token bus_token)821 static int gic_ipi_domain_match(struct irq_domain *d, struct device_node *node,
822 				enum irq_domain_bus_token bus_token)
823 {
824 	bool is_ipi;
825 
826 	switch (bus_token) {
827 	case DOMAIN_BUS_IPI:
828 		is_ipi = d->bus_token == bus_token;
829 		return (!node || to_of_node(d->fwnode) == node) && is_ipi;
830 		break;
831 	default:
832 		return 0;
833 	}
834 }
835 
836 static const struct irq_domain_ops gic_ipi_domain_ops = {
837 	.xlate = gic_ipi_domain_xlate,
838 	.alloc = gic_ipi_domain_alloc,
839 	.free = gic_ipi_domain_free,
840 	.match = gic_ipi_domain_match,
841 };
842 
gic_register_ipi_domain(struct device_node * node)843 static int gic_register_ipi_domain(struct device_node *node)
844 {
845 	struct irq_domain *gic_ipi_domain;
846 	unsigned int v[2], num_ipis;
847 
848 	gic_ipi_domain = irq_domain_create_hierarchy(gic_irq_domain, IRQ_DOMAIN_FLAG_IPI_PER_CPU,
849 						     GIC_NUM_LOCAL_INTRS + gic_shared_intrs,
850 						     of_fwnode_handle(node), &gic_ipi_domain_ops,
851 						     NULL);
852 	if (!gic_ipi_domain) {
853 		pr_err("Failed to add IPI domain");
854 		return -ENXIO;
855 	}
856 
857 	irq_domain_update_bus_token(gic_ipi_domain, DOMAIN_BUS_IPI);
858 
859 	if (node &&
860 	    !of_property_read_u32_array(node, "mti,reserved-ipi-vectors", v, 2)) {
861 		bitmap_set(ipi_resrv, v[0], v[1]);
862 	} else {
863 		/*
864 		 * Reserve 2 interrupts per possible CPU/VP for use as IPIs,
865 		 * meeting the requirements of arch/mips SMP.
866 		 */
867 		num_ipis = 2 * num_possible_cpus();
868 		bitmap_set(ipi_resrv, gic_shared_intrs - num_ipis, num_ipis);
869 	}
870 
871 	bitmap_copy(ipi_available, ipi_resrv, GIC_MAX_INTRS);
872 
873 	return 0;
874 }
875 
876 #else /* !CONFIG_GENERIC_IRQ_IPI */
877 
gic_register_ipi_domain(struct device_node * node)878 static inline int gic_register_ipi_domain(struct device_node *node)
879 {
880 	return 0;
881 }
882 
883 #endif /* !CONFIG_GENERIC_IRQ_IPI */
884 
gic_cpu_startup(unsigned int cpu)885 static int gic_cpu_startup(unsigned int cpu)
886 {
887 	/* Enable or disable EIC */
888 	change_gic_vl_ctl(GIC_VX_CTL_EIC,
889 			  cpu_has_veic ? GIC_VX_CTL_EIC : 0);
890 
891 	/* Clear all local IRQ masks (ie. disable all local interrupts) */
892 	write_gic_vl_rmask(~0);
893 
894 	/* Enable desired interrupts */
895 	gic_all_vpes_irq_cpu_online();
896 
897 	return 0;
898 }
899 
gic_of_init(struct device_node * node,struct device_node * parent)900 static int __init gic_of_init(struct device_node *node,
901 			      struct device_node *parent)
902 {
903 	unsigned int cpu_vec, i, gicconfig, cl, nclusters;
904 	unsigned long reserved;
905 	phys_addr_t gic_base;
906 	struct resource res;
907 	size_t gic_len;
908 	int ret;
909 
910 	/* Find the first available CPU vector. */
911 	i = 0;
912 	reserved = (C_SW0 | C_SW1) >> __ffs(C_SW0);
913 	while (!of_property_read_u32_index(node, "mti,reserved-cpu-vectors",
914 					   i++, &cpu_vec))
915 		reserved |= BIT(cpu_vec);
916 
917 	cpu_vec = find_first_zero_bit(&reserved, hweight_long(ST0_IM));
918 	if (cpu_vec == hweight_long(ST0_IM)) {
919 		pr_err("No CPU vectors available\n");
920 		return -ENODEV;
921 	}
922 
923 	if (of_address_to_resource(node, 0, &res)) {
924 		/*
925 		 * Probe the CM for the GIC base address if not specified
926 		 * in the device-tree.
927 		 */
928 		if (mips_cm_present()) {
929 			gic_base = read_gcr_gic_base() &
930 				~CM_GCR_GIC_BASE_GICEN;
931 			gic_len = 0x20000;
932 			pr_warn("Using inherited base address %pa\n",
933 				&gic_base);
934 		} else {
935 			pr_err("Failed to get memory range\n");
936 			return -ENODEV;
937 		}
938 	} else {
939 		gic_base = res.start;
940 		gic_len = resource_size(&res);
941 	}
942 
943 	if (mips_cm_present()) {
944 		write_gcr_gic_base(gic_base | CM_GCR_GIC_BASE_GICEN);
945 		/* Ensure GIC region is enabled before trying to access it */
946 		__sync();
947 	}
948 
949 	mips_gic_base = ioremap(gic_base, gic_len);
950 	if (!mips_gic_base) {
951 		pr_err("Failed to ioremap gic_base\n");
952 		return -ENOMEM;
953 	}
954 
955 	gicconfig = read_gic_config();
956 	gic_shared_intrs = FIELD_GET(GIC_CONFIG_NUMINTERRUPTS, gicconfig);
957 	gic_shared_intrs = (gic_shared_intrs + 1) * 8;
958 
959 	if (cpu_has_veic) {
960 		/* Always use vector 1 in EIC mode */
961 		gic_cpu_pin = 0;
962 		set_vi_handler(gic_cpu_pin + GIC_PIN_TO_VEC_OFFSET,
963 			       __gic_irq_dispatch);
964 	} else {
965 		gic_cpu_pin = cpu_vec - GIC_CPU_PIN_OFFSET;
966 		irq_set_chained_handler(MIPS_CPU_IRQ_BASE + cpu_vec,
967 					gic_irq_dispatch);
968 	}
969 
970 	gic_irq_domain = irq_domain_create_simple(of_fwnode_handle(node),
971 						  GIC_NUM_LOCAL_INTRS +
972 						  gic_shared_intrs, 0,
973 						  &gic_irq_domain_ops, NULL);
974 	if (!gic_irq_domain) {
975 		pr_err("Failed to add IRQ domain");
976 		return -ENXIO;
977 	}
978 
979 	ret = gic_register_ipi_domain(node);
980 	if (ret)
981 		return ret;
982 
983 	board_bind_eic_interrupt = &gic_bind_eic_interrupt;
984 
985 	/*
986 	 * Initialise each cluster's GIC shared registers to sane default
987 	 * values.
988 	 * Otherwise, the IPI set up will be erased if we move code
989 	 * to gic_cpu_startup for each cpu.
990 	 */
991 	nclusters = mips_cps_numclusters();
992 	for (cl = 0; cl < nclusters; cl++) {
993 		if (cl == cpu_cluster(&current_cpu_data)) {
994 			for (i = 0; i < gic_shared_intrs; i++) {
995 				change_gic_pol(i, GIC_POL_ACTIVE_HIGH);
996 				change_gic_trig(i, GIC_TRIG_LEVEL);
997 				write_gic_rmask(i);
998 			}
999 		} else if (mips_cps_numcores(cl) != 0) {
1000 			mips_cm_lock_other(cl, 0, 0, CM_GCR_Cx_OTHER_BLOCK_GLOBAL);
1001 			for (i = 0; i < gic_shared_intrs; i++) {
1002 				change_gic_redir_pol(i, GIC_POL_ACTIVE_HIGH);
1003 				change_gic_redir_trig(i, GIC_TRIG_LEVEL);
1004 				write_gic_redir_rmask(i);
1005 			}
1006 			mips_cm_unlock_other();
1007 
1008 		} else {
1009 			pr_warn("No CPU cores on the cluster %d skip it\n", cl);
1010 		}
1011 	}
1012 
1013 	return cpuhp_setup_state(CPUHP_AP_IRQ_MIPS_GIC_STARTING,
1014 				 "irqchip/mips/gic:starting",
1015 				 gic_cpu_startup, NULL);
1016 }
1017 IRQCHIP_DECLARE(mips_gic, "mti,gic", gic_of_init);
1018