1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Loongson Extend I/O Interrupt Controller support
4  *
5  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
6  */
7 
8 #define pr_fmt(fmt) "eiointc: " fmt
9 
10 #include <linux/cpuhotplug.h>
11 #include <linux/interrupt.h>
12 #include <linux/irq.h>
13 #include <linux/irqchip.h>
14 #include <linux/irqdomain.h>
15 #include <linux/irqchip/chained_irq.h>
16 #include <linux/kernel.h>
17 #include <linux/syscore_ops.h>
18 
19 #define EIOINTC_REG_NODEMAP	0x14a0
20 #define EIOINTC_REG_IPMAP	0x14c0
21 #define EIOINTC_REG_ENABLE	0x1600
22 #define EIOINTC_REG_BOUNCE	0x1680
23 #define EIOINTC_REG_ISR		0x1800
24 #define EIOINTC_REG_ROUTE	0x1c00
25 
26 #define VEC_REG_COUNT		4
27 #define VEC_COUNT_PER_REG	64
28 #define VEC_COUNT		(VEC_REG_COUNT * VEC_COUNT_PER_REG)
29 #define VEC_REG_IDX(irq_id)	((irq_id) / VEC_COUNT_PER_REG)
30 #define VEC_REG_BIT(irq_id)     ((irq_id) % VEC_COUNT_PER_REG)
31 #define EIOINTC_ALL_ENABLE	0xffffffff
32 
33 #define MAX_EIO_NODES		(NR_CPUS / CORES_PER_EIO_NODE)
34 
35 static int nr_pics;
36 
37 struct eiointc_priv {
38 	u32			node;
39 	u32			vec_count;
40 	nodemask_t		node_map;
41 	cpumask_t		cpuspan_map;
42 	struct fwnode_handle	*domain_handle;
43 	struct irq_domain	*eiointc_domain;
44 };
45 
46 static struct eiointc_priv *eiointc_priv[MAX_IO_PICS];
47 
48 static void eiointc_enable(void)
49 {
50 	uint64_t misc;
51 
52 	misc = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
53 	misc |= IOCSR_MISC_FUNC_EXT_IOI_EN;
54 	iocsr_write64(misc, LOONGARCH_IOCSR_MISC_FUNC);
55 }
56 
57 static int cpu_to_eio_node(int cpu)
58 {
59 	return cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
60 }
61 
62 static void eiointc_set_irq_route(int pos, unsigned int cpu, unsigned int mnode, nodemask_t *node_map)
63 {
64 	int i, node, cpu_node, route_node;
65 	unsigned char coremap;
66 	uint32_t pos_off, data, data_byte, data_mask;
67 
68 	pos_off = pos & ~3;
69 	data_byte = pos & 3;
70 	data_mask = ~BIT_MASK(data_byte) & 0xf;
71 
72 	/* Calculate node and coremap of target irq */
73 	cpu_node = cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
74 	coremap = BIT(cpu_logical_map(cpu) % CORES_PER_EIO_NODE);
75 
76 	for_each_online_cpu(i) {
77 		node = cpu_to_eio_node(i);
78 		if (!node_isset(node, *node_map))
79 			continue;
80 
81 		/* EIO node 0 is in charge of inter-node interrupt dispatch */
82 		route_node = (node == mnode) ? cpu_node : node;
83 		data = ((coremap | (route_node << 4)) << (data_byte * 8));
84 		csr_any_send(EIOINTC_REG_ROUTE + pos_off, data, data_mask, node * CORES_PER_EIO_NODE);
85 	}
86 }
87 
88 static DEFINE_RAW_SPINLOCK(affinity_lock);
89 
90 static int eiointc_set_irq_affinity(struct irq_data *d, const struct cpumask *affinity, bool force)
91 {
92 	unsigned int cpu;
93 	unsigned long flags;
94 	uint32_t vector, regaddr;
95 	struct cpumask intersect_affinity;
96 	struct eiointc_priv *priv = d->domain->host_data;
97 
98 	raw_spin_lock_irqsave(&affinity_lock, flags);
99 
100 	cpumask_and(&intersect_affinity, affinity, cpu_online_mask);
101 	cpumask_and(&intersect_affinity, &intersect_affinity, &priv->cpuspan_map);
102 
103 	if (cpumask_empty(&intersect_affinity)) {
104 		raw_spin_unlock_irqrestore(&affinity_lock, flags);
105 		return -EINVAL;
106 	}
107 	cpu = cpumask_first(&intersect_affinity);
108 
109 	vector = d->hwirq;
110 	regaddr = EIOINTC_REG_ENABLE + ((vector >> 5) << 2);
111 
112 	/* Mask target vector */
113 	csr_any_send(regaddr, EIOINTC_ALL_ENABLE & (~BIT(vector & 0x1F)),
114 			0x0, priv->node * CORES_PER_EIO_NODE);
115 
116 	/* Set route for target vector */
117 	eiointc_set_irq_route(vector, cpu, priv->node, &priv->node_map);
118 
119 	/* Unmask target vector */
120 	csr_any_send(regaddr, EIOINTC_ALL_ENABLE,
121 			0x0, priv->node * CORES_PER_EIO_NODE);
122 
123 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
124 
125 	raw_spin_unlock_irqrestore(&affinity_lock, flags);
126 
127 	return IRQ_SET_MASK_OK;
128 }
129 
130 static int eiointc_index(int node)
131 {
132 	int i;
133 
134 	for (i = 0; i < nr_pics; i++) {
135 		if (node_isset(node, eiointc_priv[i]->node_map))
136 			return i;
137 	}
138 
139 	return -1;
140 }
141 
142 static int eiointc_router_init(unsigned int cpu)
143 {
144 	int i, bit;
145 	uint32_t data;
146 	uint32_t node = cpu_to_eio_node(cpu);
147 	int index = eiointc_index(node);
148 
149 	if (index < 0) {
150 		pr_err("Error: invalid nodemap!\n");
151 		return -1;
152 	}
153 
154 	if ((cpu_logical_map(cpu) % CORES_PER_EIO_NODE) == 0) {
155 		eiointc_enable();
156 
157 		for (i = 0; i < eiointc_priv[0]->vec_count / 32; i++) {
158 			data = (((1 << (i * 2 + 1)) << 16) | (1 << (i * 2)));
159 			iocsr_write32(data, EIOINTC_REG_NODEMAP + i * 4);
160 		}
161 
162 		for (i = 0; i < eiointc_priv[0]->vec_count / 32 / 4; i++) {
163 			bit = BIT(1 + index); /* Route to IP[1 + index] */
164 			data = bit | (bit << 8) | (bit << 16) | (bit << 24);
165 			iocsr_write32(data, EIOINTC_REG_IPMAP + i * 4);
166 		}
167 
168 		for (i = 0; i < eiointc_priv[0]->vec_count / 4; i++) {
169 			/* Route to Node-0 Core-0 */
170 			if (index == 0)
171 				bit = BIT(cpu_logical_map(0));
172 			else
173 				bit = (eiointc_priv[index]->node << 4) | 1;
174 
175 			data = bit | (bit << 8) | (bit << 16) | (bit << 24);
176 			iocsr_write32(data, EIOINTC_REG_ROUTE + i * 4);
177 		}
178 
179 		for (i = 0; i < eiointc_priv[0]->vec_count / 32; i++) {
180 			data = 0xffffffff;
181 			iocsr_write32(data, EIOINTC_REG_ENABLE + i * 4);
182 			iocsr_write32(data, EIOINTC_REG_BOUNCE + i * 4);
183 		}
184 	}
185 
186 	return 0;
187 }
188 
189 static void eiointc_irq_dispatch(struct irq_desc *desc)
190 {
191 	int i;
192 	u64 pending;
193 	bool handled = false;
194 	struct irq_chip *chip = irq_desc_get_chip(desc);
195 	struct eiointc_priv *priv = irq_desc_get_handler_data(desc);
196 
197 	chained_irq_enter(chip, desc);
198 
199 	for (i = 0; i < eiointc_priv[0]->vec_count / VEC_COUNT_PER_REG; i++) {
200 		pending = iocsr_read64(EIOINTC_REG_ISR + (i << 3));
201 		iocsr_write64(pending, EIOINTC_REG_ISR + (i << 3));
202 		while (pending) {
203 			int bit = __ffs(pending);
204 			int irq = bit + VEC_COUNT_PER_REG * i;
205 
206 			generic_handle_domain_irq(priv->eiointc_domain, irq);
207 			pending &= ~BIT(bit);
208 			handled = true;
209 		}
210 	}
211 
212 	if (!handled)
213 		spurious_interrupt();
214 
215 	chained_irq_exit(chip, desc);
216 }
217 
218 static void eiointc_ack_irq(struct irq_data *d)
219 {
220 }
221 
222 static void eiointc_mask_irq(struct irq_data *d)
223 {
224 }
225 
226 static void eiointc_unmask_irq(struct irq_data *d)
227 {
228 }
229 
230 static struct irq_chip eiointc_irq_chip = {
231 	.name			= "EIOINTC",
232 	.irq_ack		= eiointc_ack_irq,
233 	.irq_mask		= eiointc_mask_irq,
234 	.irq_unmask		= eiointc_unmask_irq,
235 	.irq_set_affinity	= eiointc_set_irq_affinity,
236 };
237 
238 static int eiointc_domain_alloc(struct irq_domain *domain, unsigned int virq,
239 				unsigned int nr_irqs, void *arg)
240 {
241 	int ret;
242 	unsigned int i, type;
243 	unsigned long hwirq = 0;
244 	struct eiointc_priv *priv = domain->host_data;
245 
246 	ret = irq_domain_translate_onecell(domain, arg, &hwirq, &type);
247 	if (ret)
248 		return ret;
249 
250 	for (i = 0; i < nr_irqs; i++) {
251 		irq_domain_set_info(domain, virq + i, hwirq + i, &eiointc_irq_chip,
252 					priv, handle_edge_irq, NULL, NULL);
253 	}
254 
255 	return 0;
256 }
257 
258 static void eiointc_domain_free(struct irq_domain *domain, unsigned int virq,
259 				unsigned int nr_irqs)
260 {
261 	int i;
262 
263 	for (i = 0; i < nr_irqs; i++) {
264 		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
265 
266 		irq_set_handler(virq + i, NULL);
267 		irq_domain_reset_irq_data(d);
268 	}
269 }
270 
271 static const struct irq_domain_ops eiointc_domain_ops = {
272 	.translate	= irq_domain_translate_onecell,
273 	.alloc		= eiointc_domain_alloc,
274 	.free		= eiointc_domain_free,
275 };
276 
277 static void acpi_set_vec_parent(int node, struct irq_domain *parent, struct acpi_vector_group *vec_group)
278 {
279 	int i;
280 
281 	for (i = 0; i < MAX_IO_PICS; i++) {
282 		if (node == vec_group[i].node) {
283 			vec_group[i].parent = parent;
284 			return;
285 		}
286 	}
287 }
288 
289 static struct irq_domain *acpi_get_vec_parent(int node, struct acpi_vector_group *vec_group)
290 {
291 	int i;
292 
293 	for (i = 0; i < MAX_IO_PICS; i++) {
294 		if (node == vec_group[i].node)
295 			return vec_group[i].parent;
296 	}
297 	return NULL;
298 }
299 
300 static int eiointc_suspend(void)
301 {
302 	return 0;
303 }
304 
305 static void eiointc_resume(void)
306 {
307 	int i, j;
308 	struct irq_desc *desc;
309 	struct irq_data *irq_data;
310 
311 	eiointc_router_init(0);
312 
313 	for (i = 0; i < nr_pics; i++) {
314 		for (j = 0; j < eiointc_priv[0]->vec_count; j++) {
315 			desc = irq_resolve_mapping(eiointc_priv[i]->eiointc_domain, j);
316 			if (desc && desc->handle_irq && desc->handle_irq != handle_bad_irq) {
317 				raw_spin_lock(&desc->lock);
318 				irq_data = irq_domain_get_irq_data(eiointc_priv[i]->eiointc_domain, irq_desc_get_irq(desc));
319 				eiointc_set_irq_affinity(irq_data, irq_data->common->affinity, 0);
320 				raw_spin_unlock(&desc->lock);
321 			}
322 		}
323 	}
324 }
325 
326 static struct syscore_ops eiointc_syscore_ops = {
327 	.suspend = eiointc_suspend,
328 	.resume = eiointc_resume,
329 };
330 
331 static int __init pch_pic_parse_madt(union acpi_subtable_headers *header,
332 					const unsigned long end)
333 {
334 	struct acpi_madt_bio_pic *pchpic_entry = (struct acpi_madt_bio_pic *)header;
335 	unsigned int node = (pchpic_entry->address >> 44) & 0xf;
336 	struct irq_domain *parent = acpi_get_vec_parent(node, pch_group);
337 
338 	if (parent)
339 		return pch_pic_acpi_init(parent, pchpic_entry);
340 
341 	return 0;
342 }
343 
344 static int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
345 					const unsigned long end)
346 {
347 	struct irq_domain *parent;
348 	struct acpi_madt_msi_pic *pchmsi_entry = (struct acpi_madt_msi_pic *)header;
349 	int node;
350 
351 	if (cpu_has_flatmode)
352 		node = cpu_to_node(eiointc_priv[nr_pics - 1]->node * CORES_PER_EIO_NODE);
353 	else
354 		node = eiointc_priv[nr_pics - 1]->node;
355 
356 	parent = acpi_get_vec_parent(node, msi_group);
357 
358 	if (parent)
359 		return pch_msi_acpi_init(parent, pchmsi_entry);
360 
361 	return 0;
362 }
363 
364 static int __init acpi_cascade_irqdomain_init(void)
365 {
366 	int r;
367 
368 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_BIO_PIC, pch_pic_parse_madt, 0);
369 	if (r < 0)
370 		return r;
371 
372 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_MSI_PIC, pch_msi_parse_madt, 1);
373 	if (r < 0)
374 		return r;
375 
376 	return 0;
377 }
378 
379 static int __init eiointc_init(struct eiointc_priv *priv, int parent_irq,
380 			       u64 node_map)
381 {
382 	int i;
383 
384 	node_map = node_map ? node_map : -1ULL;
385 	for_each_possible_cpu(i) {
386 		if (node_map & (1ULL << (cpu_to_eio_node(i)))) {
387 			node_set(cpu_to_eio_node(i), priv->node_map);
388 			cpumask_or(&priv->cpuspan_map, &priv->cpuspan_map,
389 				   cpumask_of(i));
390 		}
391 	}
392 
393 	priv->eiointc_domain = irq_domain_create_linear(priv->domain_handle,
394 							priv->vec_count,
395 							&eiointc_domain_ops,
396 							priv);
397 	if (!priv->eiointc_domain) {
398 		pr_err("loongson-extioi: cannot add IRQ domain\n");
399 		return -ENOMEM;
400 	}
401 
402 	eiointc_priv[nr_pics++] = priv;
403 	eiointc_router_init(0);
404 	irq_set_chained_handler_and_data(parent_irq, eiointc_irq_dispatch, priv);
405 
406 	if (nr_pics == 1) {
407 		register_syscore_ops(&eiointc_syscore_ops);
408 		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_LOONGARCH_STARTING,
409 					  "irqchip/loongarch/intc:starting",
410 					  eiointc_router_init, NULL);
411 	}
412 
413 	return 0;
414 }
415 
416 int __init eiointc_acpi_init(struct irq_domain *parent,
417 				     struct acpi_madt_eio_pic *acpi_eiointc)
418 {
419 	int parent_irq, ret;
420 	struct eiointc_priv *priv;
421 	int node;
422 
423 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
424 	if (!priv)
425 		return -ENOMEM;
426 
427 	priv->domain_handle = irq_domain_alloc_named_id_fwnode("EIOPIC",
428 							       acpi_eiointc->node);
429 	if (!priv->domain_handle) {
430 		pr_err("Unable to allocate domain handle\n");
431 		goto out_free_priv;
432 	}
433 
434 	priv->vec_count = VEC_COUNT;
435 	priv->node = acpi_eiointc->node;
436 
437 	parent_irq = irq_create_mapping(parent, acpi_eiointc->cascade);
438 
439 	ret = eiointc_init(priv, parent_irq, acpi_eiointc->node_map);
440 	if (ret < 0)
441 		goto out_free_handle;
442 
443 	if (cpu_has_flatmode)
444 		node = cpu_to_node(acpi_eiointc->node * CORES_PER_EIO_NODE);
445 	else
446 		node = acpi_eiointc->node;
447 	acpi_set_vec_parent(node, priv->eiointc_domain, pch_group);
448 	acpi_set_vec_parent(node, priv->eiointc_domain, msi_group);
449 
450 	ret = acpi_cascade_irqdomain_init();
451 	if (ret < 0)
452 		goto out_free_handle;
453 
454 	return ret;
455 
456 out_free_handle:
457 	irq_domain_free_fwnode(priv->domain_handle);
458 	priv->domain_handle = NULL;
459 out_free_priv:
460 	kfree(priv);
461 
462 	return -ENOMEM;
463 }
464 
465 static int __init eiointc_of_init(struct device_node *of_node,
466 				  struct device_node *parent)
467 {
468 	int parent_irq, ret;
469 	struct eiointc_priv *priv;
470 
471 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
472 	if (!priv)
473 		return -ENOMEM;
474 
475 	parent_irq = irq_of_parse_and_map(of_node, 0);
476 	if (parent_irq <= 0) {
477 		ret = -ENODEV;
478 		goto out_free_priv;
479 	}
480 
481 	ret = irq_set_handler_data(parent_irq, priv);
482 	if (ret < 0)
483 		goto out_free_priv;
484 
485 	/*
486 	 * In particular, the number of devices supported by the LS2K0500
487 	 * extended I/O interrupt vector is 128.
488 	 */
489 	if (of_device_is_compatible(of_node, "loongson,ls2k0500-eiointc"))
490 		priv->vec_count = 128;
491 	else
492 		priv->vec_count = VEC_COUNT;
493 
494 	priv->node = 0;
495 	priv->domain_handle = of_node_to_fwnode(of_node);
496 
497 	ret = eiointc_init(priv, parent_irq, 0);
498 	if (ret < 0)
499 		goto out_free_priv;
500 
501 	return 0;
502 
503 out_free_priv:
504 	kfree(priv);
505 	return ret;
506 }
507 
508 IRQCHIP_DECLARE(loongson_ls2k0500_eiointc, "loongson,ls2k0500-eiointc", eiointc_of_init);
509 IRQCHIP_DECLARE(loongson_ls2k2000_eiointc, "loongson,ls2k2000-eiointc", eiointc_of_init);
510