xref: /linux/drivers/irqchip/irq-armada-370-xp.c (revision 0b29600a304c0c5da17ce1a7fab7cafb0eaf71f5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Marvell Armada 370 and Armada XP SoC IRQ handling
4  *
5  * Copyright (C) 2012 Marvell
6  *
7  * Lior Amsalem <alior@marvell.com>
8  * Gregory CLEMENT <gregory.clement@free-electrons.com>
9  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
10  * Ben Dooks <ben.dooks@codethink.co.uk>
11  */
12 
13 #include <linux/bitfield.h>
14 #include <linux/bits.h>
15 #include <linux/err.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/irq.h>
20 #include <linux/interrupt.h>
21 #include <linux/irqchip.h>
22 #include <linux/irqchip/chained_irq.h>
23 #include <linux/irqchip/irq-msi-lib.h>
24 #include <linux/cpu.h>
25 #include <linux/io.h>
26 #include <linux/of_address.h>
27 #include <linux/of_irq.h>
28 #include <linux/of_pci.h>
29 #include <linux/irqdomain.h>
30 #include <linux/slab.h>
31 #include <linux/syscore_ops.h>
32 #include <linux/msi.h>
33 #include <linux/types.h>
34 #include <asm/mach/arch.h>
35 #include <asm/exception.h>
36 #include <asm/smp_plat.h>
37 #include <asm/mach/irq.h>
38 
39 /*
40  * Overall diagram of the Armada XP interrupt controller:
41  *
42  *    To CPU 0                 To CPU 1
43  *
44  *       /\                       /\
45  *       ||                       ||
46  * +---------------+     +---------------+
47  * |               |	 |               |
48  * |    per-CPU    |	 |    per-CPU    |
49  * |  mask/unmask  |	 |  mask/unmask  |
50  * |     CPU0      |	 |     CPU1      |
51  * |               |	 |               |
52  * +---------------+	 +---------------+
53  *        /\                       /\
54  *        ||                       ||
55  *        \\_______________________//
56  *                     ||
57  *            +-------------------+
58  *            |                   |
59  *            | Global interrupt  |
60  *            |    mask/unmask    |
61  *            |                   |
62  *            +-------------------+
63  *                     /\
64  *                     ||
65  *               interrupt from
66  *                   device
67  *
68  * The "global interrupt mask/unmask" is modified using the
69  * MPIC_INT_SET_ENABLE and MPIC_INT_CLEAR_ENABLE
70  * registers, which are relative to "mpic->base".
71  *
72  * The "per-CPU mask/unmask" is modified using the MPIC_INT_SET_MASK
73  * and MPIC_INT_CLEAR_MASK registers, which are relative to
74  * "mpic->per_cpu". This base address points to a special address,
75  * which automatically accesses the registers of the current CPU.
76  *
77  * The per-CPU mask/unmask can also be adjusted using the global
78  * per-interrupt MPIC_INT_SOURCE_CTL register, which we use to
79  * configure interrupt affinity.
80  *
81  * Due to this model, all interrupts need to be mask/unmasked at two
82  * different levels: at the global level and at the per-CPU level.
83  *
84  * This driver takes the following approach to deal with this:
85  *
86  *  - For global interrupts:
87  *
88  *    At ->map() time, a global interrupt is unmasked at the per-CPU
89  *    mask/unmask level. It is therefore unmasked at this level for
90  *    the current CPU, running the ->map() code. This allows to have
91  *    the interrupt unmasked at this level in non-SMP
92  *    configurations. In SMP configurations, the ->set_affinity()
93  *    callback is called, which using the MPIC_INT_SOURCE_CTL()
94  *    readjusts the per-CPU mask/unmask for the interrupt.
95  *
96  *    The ->mask() and ->unmask() operations only mask/unmask the
97  *    interrupt at the "global" level.
98  *
99  *    So, a global interrupt is enabled at the per-CPU level as soon
100  *    as it is mapped. At run time, the masking/unmasking takes place
101  *    at the global level.
102  *
103  *  - For per-CPU interrupts
104  *
105  *    At ->map() time, a per-CPU interrupt is unmasked at the global
106  *    mask/unmask level.
107  *
108  *    The ->mask() and ->unmask() operations mask/unmask the interrupt
109  *    at the per-CPU level.
110  *
111  *    So, a per-CPU interrupt is enabled at the global level as soon
112  *    as it is mapped. At run time, the masking/unmasking takes place
113  *    at the per-CPU level.
114  */
115 
116 /* Registers relative to mpic->base */
117 #define MPIC_INT_CONTROL			0x00
118 #define MPIC_INT_CONTROL_NUMINT_MASK		GENMASK(12, 2)
119 #define MPIC_SW_TRIG_INT			0x04
120 #define MPIC_INT_SET_ENABLE			0x30
121 #define MPIC_INT_CLEAR_ENABLE			0x34
122 #define MPIC_INT_SOURCE_CTL(hwirq)		(0x100 + (hwirq) * 4)
123 #define MPIC_INT_SOURCE_CPU_MASK		GENMASK(3, 0)
124 #define MPIC_INT_IRQ_FIQ_MASK(cpuid)		((BIT(0) | BIT(8)) << (cpuid))
125 
126 /* Registers relative to mpic->per_cpu */
127 #define MPIC_IN_DRBEL_CAUSE			0x08
128 #define MPIC_IN_DRBEL_MASK			0x0c
129 #define MPIC_PPI_CAUSE				0x10
130 #define MPIC_CPU_INTACK				0x44
131 #define MPIC_CPU_INTACK_IID_MASK		GENMASK(9, 0)
132 #define MPIC_INT_SET_MASK			0x48
133 #define MPIC_INT_CLEAR_MASK			0x4C
134 #define MPIC_INT_FABRIC_MASK			0x54
135 #define MPIC_INT_CAUSE_PERF(cpu)		BIT(cpu)
136 
137 #define MPIC_PER_CPU_IRQS_NR			29
138 
139 /* IPI and MSI interrupt definitions for IPI platforms */
140 #define IPI_DOORBELL_NR				8
141 #define IPI_DOORBELL_MASK			GENMASK(7, 0)
142 #define PCI_MSI_DOORBELL_START			16
143 #define PCI_MSI_DOORBELL_NR			16
144 #define PCI_MSI_DOORBELL_MASK			GENMASK(31, 16)
145 
146 /* MSI interrupt definitions for non-IPI platforms */
147 #define PCI_MSI_FULL_DOORBELL_START		0
148 #define PCI_MSI_FULL_DOORBELL_NR		32
149 #define PCI_MSI_FULL_DOORBELL_MASK		GENMASK(31, 0)
150 #define PCI_MSI_FULL_DOORBELL_SRC0_MASK		GENMASK(15, 0)
151 #define PCI_MSI_FULL_DOORBELL_SRC1_MASK		GENMASK(31, 16)
152 
153 /**
154  * struct mpic - MPIC private data structure
155  * @base:		MPIC registers base address
156  * @per_cpu:		per-CPU registers base address
157  * @parent_irq:		parent IRQ if MPIC is not top-level interrupt controller
158  * @domain:		MPIC main interrupt domain
159  * @ipi_domain:		IPI domain
160  * @msi_inner_domain:	MSI inner domain
161  * @msi_used:		bitmap of used MSI numbers
162  * @msi_lock:		mutex serializing access to @msi_used
163  * @msi_doorbell_addr:	physical address of MSI doorbell register
164  * @msi_doorbell_mask:	mask of available doorbell bits for MSIs (either PCI_MSI_DOORBELL_MASK or
165  *			PCI_MSI_FULL_DOORBELL_MASK)
166  * @msi_doorbell_start:	first set bit in @msi_doorbell_mask
167  * @msi_doorbell_size:	number of set bits in @msi_doorbell_mask
168  * @doorbell_mask:	doorbell mask of MSIs and IPIs, stored on suspend, restored on resume
169  */
170 struct mpic {
171 	void __iomem *base;
172 	void __iomem *per_cpu;
173 	int parent_irq;
174 	struct irq_domain *domain;
175 #ifdef CONFIG_SMP
176 	struct irq_domain *ipi_domain;
177 #endif
178 #ifdef CONFIG_PCI_MSI
179 	struct irq_domain *msi_inner_domain;
180 	DECLARE_BITMAP(msi_used, PCI_MSI_FULL_DOORBELL_NR);
181 	struct mutex msi_lock;
182 	phys_addr_t msi_doorbell_addr;
183 	u32 msi_doorbell_mask;
184 	unsigned int msi_doorbell_start, msi_doorbell_size;
185 #endif
186 	u32 doorbell_mask;
187 };
188 
189 static struct mpic *mpic_data __ro_after_init;
190 
mpic_is_ipi_available(struct mpic * mpic)191 static inline bool mpic_is_ipi_available(struct mpic *mpic)
192 {
193 	/*
194 	 * We distinguish IPI availability in the IC by the IC not having a
195 	 * parent irq defined. If a parent irq is defined, there is a parent
196 	 * interrupt controller (e.g. GIC) that takes care of inter-processor
197 	 * interrupts.
198 	 */
199 	return mpic->parent_irq <= 0;
200 }
201 
mpic_is_percpu_irq(irq_hw_number_t hwirq)202 static inline bool mpic_is_percpu_irq(irq_hw_number_t hwirq)
203 {
204 	return hwirq < MPIC_PER_CPU_IRQS_NR;
205 }
206 
207 /*
208  * In SMP mode:
209  * For shared global interrupts, mask/unmask global enable bit
210  * For CPU interrupts, mask/unmask the calling CPU's bit
211  */
mpic_irq_mask(struct irq_data * d)212 static void mpic_irq_mask(struct irq_data *d)
213 {
214 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
215 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
216 
217 	if (!mpic_is_percpu_irq(hwirq))
218 		writel(hwirq, mpic->base + MPIC_INT_CLEAR_ENABLE);
219 	else
220 		writel(hwirq, mpic->per_cpu + MPIC_INT_SET_MASK);
221 }
222 
mpic_irq_unmask(struct irq_data * d)223 static void mpic_irq_unmask(struct irq_data *d)
224 {
225 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
226 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
227 
228 	if (!mpic_is_percpu_irq(hwirq))
229 		writel(hwirq, mpic->base + MPIC_INT_SET_ENABLE);
230 	else
231 		writel(hwirq, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
232 }
233 
234 #ifdef CONFIG_PCI_MSI
235 
mpic_compose_msi_msg(struct irq_data * d,struct msi_msg * msg)236 static void mpic_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
237 {
238 	unsigned int cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
239 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
240 
241 	msg->address_lo = lower_32_bits(mpic->msi_doorbell_addr);
242 	msg->address_hi = upper_32_bits(mpic->msi_doorbell_addr);
243 	msg->data = BIT(cpu + 8) | (d->hwirq + mpic->msi_doorbell_start);
244 }
245 
mpic_msi_set_affinity(struct irq_data * d,const struct cpumask * mask,bool force)246 static int mpic_msi_set_affinity(struct irq_data *d, const struct cpumask *mask, bool force)
247 {
248 	unsigned int cpu;
249 
250 	if (!force)
251 		cpu = cpumask_any_and(mask, cpu_online_mask);
252 	else
253 		cpu = cpumask_first(mask);
254 
255 	if (cpu >= nr_cpu_ids)
256 		return -EINVAL;
257 
258 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
259 
260 	return IRQ_SET_MASK_OK;
261 }
262 
263 static struct irq_chip mpic_msi_bottom_irq_chip = {
264 	.name			= "MPIC MSI",
265 	.irq_compose_msi_msg	= mpic_compose_msi_msg,
266 	.irq_set_affinity	= mpic_msi_set_affinity,
267 };
268 
mpic_msi_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * args)269 static int mpic_msi_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs,
270 			  void *args)
271 {
272 	struct mpic *mpic = domain->host_data;
273 	int hwirq;
274 
275 	mutex_lock(&mpic->msi_lock);
276 	hwirq = bitmap_find_free_region(mpic->msi_used, mpic->msi_doorbell_size,
277 					order_base_2(nr_irqs));
278 	mutex_unlock(&mpic->msi_lock);
279 
280 	if (hwirq < 0)
281 		return -ENOSPC;
282 
283 	for (unsigned int i = 0; i < nr_irqs; i++) {
284 		irq_domain_set_info(domain, virq + i, hwirq + i,
285 				    &mpic_msi_bottom_irq_chip,
286 				    domain->host_data, handle_simple_irq,
287 				    NULL, NULL);
288 	}
289 
290 	return 0;
291 }
292 
mpic_msi_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)293 static void mpic_msi_free(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs)
294 {
295 	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
296 	struct mpic *mpic = domain->host_data;
297 
298 	mutex_lock(&mpic->msi_lock);
299 	bitmap_release_region(mpic->msi_used, d->hwirq, order_base_2(nr_irqs));
300 	mutex_unlock(&mpic->msi_lock);
301 }
302 
303 static const struct irq_domain_ops mpic_msi_domain_ops = {
304 	.select	= msi_lib_irq_domain_select,
305 	.alloc	= mpic_msi_alloc,
306 	.free	= mpic_msi_free,
307 };
308 
mpic_msi_reenable_percpu(struct mpic * mpic)309 static void mpic_msi_reenable_percpu(struct mpic *mpic)
310 {
311 	u32 reg;
312 
313 	/* Enable MSI doorbell mask and combined cpu local interrupt */
314 	reg = readl(mpic->per_cpu + MPIC_IN_DRBEL_MASK);
315 	reg |= mpic->msi_doorbell_mask;
316 	writel(reg, mpic->per_cpu + MPIC_IN_DRBEL_MASK);
317 
318 	/* Unmask local doorbell interrupt */
319 	writel(1, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
320 }
321 
322 #define MPIC_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS | \
323 				 MSI_FLAG_USE_DEF_CHIP_OPS)
324 #define MPIC_MSI_FLAGS_SUPPORTED (MSI_FLAG_MULTI_PCI_MSI  | \
325 				  MSI_FLAG_PCI_MSIX       | \
326 				  MSI_GENERIC_FLAGS_MASK)
327 
328 static const struct msi_parent_ops mpic_msi_parent_ops = {
329 	.required_flags		= MPIC_MSI_FLAGS_REQUIRED,
330 	.supported_flags	= MPIC_MSI_FLAGS_SUPPORTED,
331 	.bus_select_token	= DOMAIN_BUS_NEXUS,
332 	.bus_select_mask	= MATCH_PCI_MSI,
333 	.prefix			= "MPIC-",
334 	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
335 };
336 
mpic_msi_init(struct mpic * mpic,struct device_node * node,phys_addr_t main_int_phys_base)337 static int __init mpic_msi_init(struct mpic *mpic, struct device_node *node,
338 				phys_addr_t main_int_phys_base)
339 {
340 	mpic->msi_doorbell_addr = main_int_phys_base + MPIC_SW_TRIG_INT;
341 
342 	mutex_init(&mpic->msi_lock);
343 
344 	if (mpic_is_ipi_available(mpic)) {
345 		mpic->msi_doorbell_start = PCI_MSI_DOORBELL_START;
346 		mpic->msi_doorbell_size = PCI_MSI_DOORBELL_NR;
347 		mpic->msi_doorbell_mask = PCI_MSI_DOORBELL_MASK;
348 	} else {
349 		mpic->msi_doorbell_start = PCI_MSI_FULL_DOORBELL_START;
350 		mpic->msi_doorbell_size = PCI_MSI_FULL_DOORBELL_NR;
351 		mpic->msi_doorbell_mask = PCI_MSI_FULL_DOORBELL_MASK;
352 	}
353 
354 	struct irq_domain_info info = {
355 		.fwnode		= of_fwnode_handle(node),
356 		.ops		= &mpic_msi_domain_ops,
357 		.host_data	= mpic,
358 		.size		= mpic->msi_doorbell_size,
359 	};
360 
361 	mpic->msi_inner_domain = msi_create_parent_irq_domain(&info, &mpic_msi_parent_ops);
362 	if (!mpic->msi_inner_domain)
363 		return -ENOMEM;
364 
365 	mpic_msi_reenable_percpu(mpic);
366 
367 	/* Unmask low 16 MSI irqs on non-IPI platforms */
368 	if (!mpic_is_ipi_available(mpic))
369 		writel(0, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
370 
371 	return 0;
372 }
373 #else
mpic_msi_reenable_percpu(struct mpic * mpic)374 static __maybe_unused void mpic_msi_reenable_percpu(struct mpic *mpic) {}
375 
mpic_msi_init(struct mpic * mpic,struct device_node * node,phys_addr_t main_int_phys_base)376 static inline int mpic_msi_init(struct mpic *mpic, struct device_node *node,
377 				phys_addr_t main_int_phys_base)
378 {
379 	return 0;
380 }
381 #endif
382 
mpic_perf_init(struct mpic * mpic)383 static void mpic_perf_init(struct mpic *mpic)
384 {
385 	u32 cpuid;
386 
387 	/*
388 	 * This Performance Counter Overflow interrupt is specific for
389 	 * Armada 370 and XP. It is not available on Armada 375, 38x and 39x.
390 	 */
391 	if (!of_machine_is_compatible("marvell,armada-370-xp"))
392 		return;
393 
394 	cpuid = cpu_logical_map(smp_processor_id());
395 
396 	/* Enable Performance Counter Overflow interrupts */
397 	writel(MPIC_INT_CAUSE_PERF(cpuid), mpic->per_cpu + MPIC_INT_FABRIC_MASK);
398 }
399 
400 #ifdef CONFIG_SMP
mpic_ipi_mask(struct irq_data * d)401 static void mpic_ipi_mask(struct irq_data *d)
402 {
403 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
404 	u32 reg;
405 
406 	reg = readl(mpic->per_cpu + MPIC_IN_DRBEL_MASK);
407 	reg &= ~BIT(d->hwirq);
408 	writel(reg, mpic->per_cpu + MPIC_IN_DRBEL_MASK);
409 }
410 
mpic_ipi_unmask(struct irq_data * d)411 static void mpic_ipi_unmask(struct irq_data *d)
412 {
413 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
414 	u32 reg;
415 
416 	reg = readl(mpic->per_cpu + MPIC_IN_DRBEL_MASK);
417 	reg |= BIT(d->hwirq);
418 	writel(reg, mpic->per_cpu + MPIC_IN_DRBEL_MASK);
419 }
420 
mpic_ipi_send_mask(struct irq_data * d,const struct cpumask * mask)421 static void mpic_ipi_send_mask(struct irq_data *d, const struct cpumask *mask)
422 {
423 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
424 	unsigned int cpu;
425 	u32 map = 0;
426 
427 	/* Convert our logical CPU mask into a physical one. */
428 	for_each_cpu(cpu, mask)
429 		map |= BIT(cpu_logical_map(cpu));
430 
431 	/*
432 	 * Ensure that stores to Normal memory are visible to the
433 	 * other CPUs before issuing the IPI.
434 	 */
435 	dsb();
436 
437 	/* submit softirq */
438 	writel((map << 8) | d->hwirq, mpic->base + MPIC_SW_TRIG_INT);
439 }
440 
mpic_ipi_ack(struct irq_data * d)441 static void mpic_ipi_ack(struct irq_data *d)
442 {
443 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
444 
445 	writel(~BIT(d->hwirq), mpic->per_cpu + MPIC_IN_DRBEL_CAUSE);
446 }
447 
448 static struct irq_chip mpic_ipi_irqchip = {
449 	.name		= "IPI",
450 	.irq_ack	= mpic_ipi_ack,
451 	.irq_mask	= mpic_ipi_mask,
452 	.irq_unmask	= mpic_ipi_unmask,
453 	.ipi_send_mask	= mpic_ipi_send_mask,
454 };
455 
mpic_ipi_alloc(struct irq_domain * d,unsigned int virq,unsigned int nr_irqs,void * args)456 static int mpic_ipi_alloc(struct irq_domain *d, unsigned int virq,
457 			  unsigned int nr_irqs, void *args)
458 {
459 	for (unsigned int i = 0; i < nr_irqs; i++) {
460 		irq_set_percpu_devid(virq + i);
461 		irq_domain_set_info(d, virq + i, i, &mpic_ipi_irqchip, d->host_data,
462 				    handle_percpu_devid_irq, NULL, NULL);
463 	}
464 
465 	return 0;
466 }
467 
mpic_ipi_free(struct irq_domain * d,unsigned int virq,unsigned int nr_irqs)468 static void mpic_ipi_free(struct irq_domain *d, unsigned int virq,
469 			  unsigned int nr_irqs)
470 {
471 	/* Not freeing IPIs */
472 }
473 
474 static const struct irq_domain_ops mpic_ipi_domain_ops = {
475 	.alloc	= mpic_ipi_alloc,
476 	.free	= mpic_ipi_free,
477 };
478 
mpic_ipi_resume(struct mpic * mpic)479 static void mpic_ipi_resume(struct mpic *mpic)
480 {
481 	for (irq_hw_number_t i = 0; i < IPI_DOORBELL_NR; i++) {
482 		unsigned int virq = irq_find_mapping(mpic->ipi_domain, i);
483 		struct irq_data *d;
484 
485 		if (!virq || !irq_percpu_is_enabled(virq))
486 			continue;
487 
488 		d = irq_domain_get_irq_data(mpic->ipi_domain, virq);
489 		mpic_ipi_unmask(d);
490 	}
491 }
492 
mpic_ipi_init(struct mpic * mpic,struct device_node * node)493 static int __init mpic_ipi_init(struct mpic *mpic, struct device_node *node)
494 {
495 	int base_ipi;
496 
497 	mpic->ipi_domain = irq_domain_create_linear(of_fwnode_handle(node), IPI_DOORBELL_NR,
498 						    &mpic_ipi_domain_ops, mpic);
499 	if (WARN_ON(!mpic->ipi_domain))
500 		return -ENOMEM;
501 
502 	irq_domain_update_bus_token(mpic->ipi_domain, DOMAIN_BUS_IPI);
503 	base_ipi = irq_domain_alloc_irqs(mpic->ipi_domain, IPI_DOORBELL_NR, NUMA_NO_NODE, NULL);
504 	if (WARN_ON(!base_ipi))
505 		return -ENOMEM;
506 
507 	set_smp_ipi_range(base_ipi, IPI_DOORBELL_NR);
508 
509 	return 0;
510 }
511 
mpic_set_affinity(struct irq_data * d,const struct cpumask * mask_val,bool force)512 static int mpic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, bool force)
513 {
514 	struct mpic *mpic = irq_data_get_irq_chip_data(d);
515 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
516 	unsigned int cpu;
517 
518 	/* Select a single core from the affinity mask which is online */
519 	cpu = cpumask_any_and(mask_val, cpu_online_mask);
520 
521 	atomic_io_modify(mpic->base + MPIC_INT_SOURCE_CTL(hwirq),
522 			 MPIC_INT_SOURCE_CPU_MASK, BIT(cpu_logical_map(cpu)));
523 
524 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
525 
526 	return IRQ_SET_MASK_OK;
527 }
528 
mpic_smp_cpu_init(struct mpic * mpic)529 static void mpic_smp_cpu_init(struct mpic *mpic)
530 {
531 	for (irq_hw_number_t i = 0; i < mpic->domain->hwirq_max; i++)
532 		writel(i, mpic->per_cpu + MPIC_INT_SET_MASK);
533 
534 	if (!mpic_is_ipi_available(mpic))
535 		return;
536 
537 	/* Disable all IPIs */
538 	writel(0, mpic->per_cpu + MPIC_IN_DRBEL_MASK);
539 
540 	/* Clear pending IPIs */
541 	writel(0, mpic->per_cpu + MPIC_IN_DRBEL_CAUSE);
542 
543 	/* Unmask IPI interrupt */
544 	writel(0, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
545 }
546 
mpic_reenable_percpu(struct mpic * mpic)547 static void mpic_reenable_percpu(struct mpic *mpic)
548 {
549 	/* Re-enable per-CPU interrupts that were enabled before suspend */
550 	for (irq_hw_number_t i = 0; i < MPIC_PER_CPU_IRQS_NR; i++) {
551 		unsigned int virq = irq_find_mapping(mpic->domain, i);
552 		struct irq_data *d;
553 
554 		if (!virq || !irq_percpu_is_enabled(virq))
555 			continue;
556 
557 		d = irq_get_irq_data(virq);
558 		mpic_irq_unmask(d);
559 	}
560 
561 	if (mpic_is_ipi_available(mpic))
562 		mpic_ipi_resume(mpic);
563 
564 	mpic_msi_reenable_percpu(mpic);
565 }
566 
mpic_starting_cpu(unsigned int cpu)567 static int mpic_starting_cpu(unsigned int cpu)
568 {
569 	struct mpic *mpic = irq_get_default_domain()->host_data;
570 
571 	mpic_perf_init(mpic);
572 	mpic_smp_cpu_init(mpic);
573 	mpic_reenable_percpu(mpic);
574 
575 	return 0;
576 }
577 
mpic_cascaded_starting_cpu(unsigned int cpu)578 static int mpic_cascaded_starting_cpu(unsigned int cpu)
579 {
580 	struct mpic *mpic = mpic_data;
581 
582 	mpic_perf_init(mpic);
583 	mpic_reenable_percpu(mpic);
584 	enable_percpu_irq(mpic->parent_irq, IRQ_TYPE_NONE);
585 
586 	return 0;
587 }
588 #else
mpic_smp_cpu_init(struct mpic * mpic)589 static void mpic_smp_cpu_init(struct mpic *mpic) {}
mpic_ipi_resume(struct mpic * mpic)590 static void mpic_ipi_resume(struct mpic *mpic) {}
591 #endif
592 
593 static struct irq_chip mpic_irq_chip = {
594 	.name		= "MPIC",
595 	.irq_mask	= mpic_irq_mask,
596 	.irq_mask_ack	= mpic_irq_mask,
597 	.irq_unmask	= mpic_irq_unmask,
598 #ifdef CONFIG_SMP
599 	.irq_set_affinity = mpic_set_affinity,
600 #endif
601 	.flags		= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND,
602 };
603 
mpic_irq_map(struct irq_domain * domain,unsigned int virq,irq_hw_number_t hwirq)604 static int mpic_irq_map(struct irq_domain *domain, unsigned int virq, irq_hw_number_t hwirq)
605 {
606 	struct mpic *mpic = domain->host_data;
607 
608 	/* IRQs 0 and 1 cannot be mapped, they are handled internally */
609 	if (hwirq <= 1)
610 		return -EINVAL;
611 
612 	irq_set_chip_data(virq, mpic);
613 
614 	mpic_irq_mask(irq_get_irq_data(virq));
615 	if (!mpic_is_percpu_irq(hwirq))
616 		writel(hwirq, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
617 	else
618 		writel(hwirq, mpic->base + MPIC_INT_SET_ENABLE);
619 	irq_set_status_flags(virq, IRQ_LEVEL);
620 
621 	if (mpic_is_percpu_irq(hwirq)) {
622 		irq_set_percpu_devid(virq);
623 		irq_set_chip_and_handler(virq, &mpic_irq_chip, handle_percpu_devid_irq);
624 	} else {
625 		irq_set_chip_and_handler(virq, &mpic_irq_chip, handle_level_irq);
626 		irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
627 	}
628 	irq_set_probe(virq);
629 	return 0;
630 }
631 
632 static const struct irq_domain_ops mpic_irq_ops = {
633 	.map	= mpic_irq_map,
634 	.xlate	= irq_domain_xlate_onecell,
635 };
636 
637 #ifdef CONFIG_PCI_MSI
mpic_handle_msi_irq(struct mpic * mpic)638 static void mpic_handle_msi_irq(struct mpic *mpic)
639 {
640 	unsigned long cause;
641 	unsigned int i;
642 
643 	cause = readl_relaxed(mpic->per_cpu + MPIC_IN_DRBEL_CAUSE);
644 	cause &= mpic->msi_doorbell_mask;
645 	writel(~cause, mpic->per_cpu + MPIC_IN_DRBEL_CAUSE);
646 
647 	for_each_set_bit(i, &cause, BITS_PER_LONG)
648 		generic_handle_domain_irq(mpic->msi_inner_domain, i - mpic->msi_doorbell_start);
649 }
650 #else
mpic_handle_msi_irq(struct mpic * mpic)651 static void mpic_handle_msi_irq(struct mpic *mpic) {}
652 #endif
653 
654 #ifdef CONFIG_SMP
mpic_handle_ipi_irq(struct mpic * mpic)655 static void mpic_handle_ipi_irq(struct mpic *mpic)
656 {
657 	unsigned long cause;
658 	irq_hw_number_t i;
659 
660 	cause = readl_relaxed(mpic->per_cpu + MPIC_IN_DRBEL_CAUSE);
661 	cause &= IPI_DOORBELL_MASK;
662 
663 	for_each_set_bit(i, &cause, IPI_DOORBELL_NR)
664 		generic_handle_domain_irq(mpic->ipi_domain, i);
665 }
666 #else
mpic_handle_ipi_irq(struct mpic * mpic)667 static inline void mpic_handle_ipi_irq(struct mpic *mpic) {}
668 #endif
669 
mpic_handle_cascade_irq(struct irq_desc * desc)670 static void mpic_handle_cascade_irq(struct irq_desc *desc)
671 {
672 	struct mpic *mpic = irq_desc_get_handler_data(desc);
673 	struct irq_chip *chip = irq_desc_get_chip(desc);
674 	unsigned long cause;
675 	u32 irqsrc, cpuid;
676 	irq_hw_number_t i;
677 
678 	chained_irq_enter(chip, desc);
679 
680 	cause = readl_relaxed(mpic->per_cpu + MPIC_PPI_CAUSE);
681 	cpuid = cpu_logical_map(smp_processor_id());
682 
683 	for_each_set_bit(i, &cause, MPIC_PER_CPU_IRQS_NR) {
684 		irqsrc = readl_relaxed(mpic->base + MPIC_INT_SOURCE_CTL(i));
685 
686 		/* Check if the interrupt is not masked on current CPU.
687 		 * Test IRQ (0-1) and FIQ (8-9) mask bits.
688 		 */
689 		if (!(irqsrc & MPIC_INT_IRQ_FIQ_MASK(cpuid)))
690 			continue;
691 
692 		if (i == 0 || i == 1) {
693 			mpic_handle_msi_irq(mpic);
694 			continue;
695 		}
696 
697 		generic_handle_domain_irq(mpic->domain, i);
698 	}
699 
700 	chained_irq_exit(chip, desc);
701 }
702 
mpic_handle_irq(struct pt_regs * regs)703 static void __exception_irq_entry mpic_handle_irq(struct pt_regs *regs)
704 {
705 	struct mpic *mpic = irq_get_default_domain()->host_data;
706 	irq_hw_number_t i;
707 	u32 irqstat;
708 
709 	do {
710 		irqstat = readl_relaxed(mpic->per_cpu + MPIC_CPU_INTACK);
711 		i = FIELD_GET(MPIC_CPU_INTACK_IID_MASK, irqstat);
712 
713 		if (i > 1022)
714 			break;
715 
716 		if (i > 1)
717 			generic_handle_domain_irq(mpic->domain, i);
718 
719 		/* MSI handling */
720 		if (i == 1)
721 			mpic_handle_msi_irq(mpic);
722 
723 		/* IPI Handling */
724 		if (i == 0)
725 			mpic_handle_ipi_irq(mpic);
726 	} while (1);
727 }
728 
mpic_suspend(void)729 static int mpic_suspend(void)
730 {
731 	struct mpic *mpic = mpic_data;
732 
733 	mpic->doorbell_mask = readl(mpic->per_cpu + MPIC_IN_DRBEL_MASK);
734 
735 	return 0;
736 }
737 
mpic_resume(void)738 static void mpic_resume(void)
739 {
740 	struct mpic *mpic = mpic_data;
741 	bool src0, src1;
742 
743 	/* Re-enable interrupts */
744 	for (irq_hw_number_t i = 0; i < mpic->domain->hwirq_max; i++) {
745 		unsigned int virq = irq_find_mapping(mpic->domain, i);
746 		struct irq_data *d;
747 
748 		if (!virq)
749 			continue;
750 
751 		d = irq_get_irq_data(virq);
752 
753 		if (!mpic_is_percpu_irq(i)) {
754 			/* Non per-CPU interrupts */
755 			writel(i, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
756 			if (!irqd_irq_disabled(d))
757 				mpic_irq_unmask(d);
758 		} else {
759 			/* Per-CPU interrupts */
760 			writel(i, mpic->base + MPIC_INT_SET_ENABLE);
761 
762 			/*
763 			 * Re-enable on the current CPU, mpic_reenable_percpu()
764 			 * will take care of secondary CPUs when they come up.
765 			 */
766 			if (irq_percpu_is_enabled(virq))
767 				mpic_irq_unmask(d);
768 		}
769 	}
770 
771 	/* Reconfigure doorbells for IPIs and MSIs */
772 	writel(mpic->doorbell_mask, mpic->per_cpu + MPIC_IN_DRBEL_MASK);
773 
774 	if (mpic_is_ipi_available(mpic)) {
775 		src0 = mpic->doorbell_mask & IPI_DOORBELL_MASK;
776 		src1 = mpic->doorbell_mask & PCI_MSI_DOORBELL_MASK;
777 	} else {
778 		src0 = mpic->doorbell_mask & PCI_MSI_FULL_DOORBELL_SRC0_MASK;
779 		src1 = mpic->doorbell_mask & PCI_MSI_FULL_DOORBELL_SRC1_MASK;
780 	}
781 
782 	if (src0)
783 		writel(0, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
784 	if (src1)
785 		writel(1, mpic->per_cpu + MPIC_INT_CLEAR_MASK);
786 
787 	if (mpic_is_ipi_available(mpic))
788 		mpic_ipi_resume(mpic);
789 }
790 
791 static struct syscore_ops mpic_syscore_ops = {
792 	.suspend	= mpic_suspend,
793 	.resume		= mpic_resume,
794 };
795 
mpic_map_region(struct device_node * np,int index,void __iomem ** base,phys_addr_t * phys_base)796 static int __init mpic_map_region(struct device_node *np, int index,
797 				  void __iomem **base, phys_addr_t *phys_base)
798 {
799 	struct resource res;
800 	int err;
801 
802 	err = of_address_to_resource(np, index, &res);
803 	if (WARN_ON(err))
804 		goto fail;
805 
806 	if (WARN_ON(!request_mem_region(res.start, resource_size(&res), np->full_name))) {
807 		err = -EBUSY;
808 		goto fail;
809 	}
810 
811 	*base = ioremap(res.start, resource_size(&res));
812 	if (WARN_ON(!*base)) {
813 		err = -ENOMEM;
814 		goto fail;
815 	}
816 
817 	if (phys_base)
818 		*phys_base = res.start;
819 
820 	return 0;
821 
822 fail:
823 	pr_err("%pOF: Unable to map resource %d: %pE\n", np, index, ERR_PTR(err));
824 	return err;
825 }
826 
mpic_of_init(struct device_node * node,struct device_node * parent)827 static int __init mpic_of_init(struct device_node *node, struct device_node *parent)
828 {
829 	phys_addr_t phys_base;
830 	unsigned int nr_irqs;
831 	struct mpic *mpic;
832 	int err;
833 
834 	mpic = kzalloc(sizeof(*mpic), GFP_KERNEL);
835 	if (WARN_ON(!mpic))
836 		return -ENOMEM;
837 
838 	mpic_data = mpic;
839 
840 	err = mpic_map_region(node, 0, &mpic->base, &phys_base);
841 	if (err)
842 		return err;
843 
844 	err = mpic_map_region(node, 1, &mpic->per_cpu, NULL);
845 	if (err)
846 		return err;
847 
848 	nr_irqs = FIELD_GET(MPIC_INT_CONTROL_NUMINT_MASK, readl(mpic->base + MPIC_INT_CONTROL));
849 
850 	for (irq_hw_number_t i = 0; i < nr_irqs; i++)
851 		writel(i, mpic->base + MPIC_INT_CLEAR_ENABLE);
852 
853 	/*
854 	 * Initialize mpic->parent_irq before calling any other functions, since
855 	 * it is used to distinguish between IPI and non-IPI platforms.
856 	 */
857 	mpic->parent_irq = irq_of_parse_and_map(node, 0);
858 
859 	/*
860 	 * On non-IPI platforms the driver currently supports only the per-CPU
861 	 * interrupts (the first 29 interrupts). See mpic_handle_cascade_irq().
862 	 */
863 	if (!mpic_is_ipi_available(mpic))
864 		nr_irqs = MPIC_PER_CPU_IRQS_NR;
865 
866 	mpic->domain = irq_domain_create_linear(of_fwnode_handle(node), nr_irqs, &mpic_irq_ops, mpic);
867 	if (!mpic->domain) {
868 		pr_err("%pOF: Unable to add IRQ domain\n", node);
869 		return -ENOMEM;
870 	}
871 
872 	irq_domain_update_bus_token(mpic->domain, DOMAIN_BUS_WIRED);
873 
874 	/* Setup for the boot CPU */
875 	mpic_perf_init(mpic);
876 	mpic_smp_cpu_init(mpic);
877 
878 	err = mpic_msi_init(mpic, node, phys_base);
879 	if (err) {
880 		pr_err("%pOF: Unable to initialize MSI domain\n", node);
881 		return err;
882 	}
883 
884 	if (mpic_is_ipi_available(mpic)) {
885 		irq_set_default_domain(mpic->domain);
886 		set_handle_irq(mpic_handle_irq);
887 #ifdef CONFIG_SMP
888 		err = mpic_ipi_init(mpic, node);
889 		if (err) {
890 			pr_err("%pOF: Unable to initialize IPI domain\n", node);
891 			return err;
892 		}
893 
894 		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_ARMADA_XP_STARTING,
895 					  "irqchip/armada/ipi:starting",
896 					  mpic_starting_cpu, NULL);
897 #endif
898 	} else {
899 #ifdef CONFIG_SMP
900 		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_ARMADA_XP_STARTING,
901 					  "irqchip/armada/cascade:starting",
902 					  mpic_cascaded_starting_cpu, NULL);
903 #endif
904 		irq_set_chained_handler_and_data(mpic->parent_irq,
905 						 mpic_handle_cascade_irq, mpic);
906 	}
907 
908 	register_syscore_ops(&mpic_syscore_ops);
909 
910 	return 0;
911 }
912 
913 IRQCHIP_DECLARE(marvell_mpic, "marvell,mpic", mpic_of_init);
914