xref: /linux/drivers/irqchip/irq-loongson-eiointc.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 #include <asm/numa.h>
19 
20 #include "irq-loongson.h"
21 
22 #define EIOINTC_REG_NODEMAP	0x14a0
23 #define EIOINTC_REG_IPMAP	0x14c0
24 #define EIOINTC_REG_ENABLE	0x1600
25 #define EIOINTC_REG_BOUNCE	0x1680
26 #define EIOINTC_REG_ISR		0x1800
27 #define EIOINTC_REG_ROUTE	0x1c00
28 
29 #define VEC_REG_COUNT		4
30 #define VEC_COUNT_PER_REG	64
31 #define VEC_COUNT		(VEC_REG_COUNT * VEC_COUNT_PER_REG)
32 #define VEC_REG_IDX(irq_id)	((irq_id) / VEC_COUNT_PER_REG)
33 #define VEC_REG_BIT(irq_id)     ((irq_id) % VEC_COUNT_PER_REG)
34 #define EIOINTC_ALL_ENABLE	0xffffffff
35 
36 #define MAX_EIO_NODES		(NR_CPUS / CORES_PER_EIO_NODE)
37 
38 static int nr_pics;
39 
40 struct eiointc_priv {
41 	u32			node;
42 	u32			vec_count;
43 	nodemask_t		node_map;
44 	cpumask_t		cpuspan_map;
45 	struct fwnode_handle	*domain_handle;
46 	struct irq_domain	*eiointc_domain;
47 };
48 
49 static struct eiointc_priv *eiointc_priv[MAX_IO_PICS];
50 
51 static void eiointc_enable(void)
52 {
53 	uint64_t misc;
54 
55 	misc = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
56 	misc |= IOCSR_MISC_FUNC_EXT_IOI_EN;
57 	iocsr_write64(misc, LOONGARCH_IOCSR_MISC_FUNC);
58 }
59 
60 static int cpu_to_eio_node(int cpu)
61 {
62 	return cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
63 }
64 
65 #ifdef CONFIG_SMP
66 static void eiointc_set_irq_route(int pos, unsigned int cpu, unsigned int mnode, nodemask_t *node_map)
67 {
68 	int i, node, cpu_node, route_node;
69 	unsigned char coremap;
70 	uint32_t pos_off, data, data_byte, data_mask;
71 
72 	pos_off = pos & ~3;
73 	data_byte = pos & 3;
74 	data_mask = ~BIT_MASK(data_byte) & 0xf;
75 
76 	/* Calculate node and coremap of target irq */
77 	cpu_node = cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
78 	coremap = BIT(cpu_logical_map(cpu) % CORES_PER_EIO_NODE);
79 
80 	for_each_online_cpu(i) {
81 		node = cpu_to_eio_node(i);
82 		if (!node_isset(node, *node_map))
83 			continue;
84 
85 		/* EIO node 0 is in charge of inter-node interrupt dispatch */
86 		route_node = (node == mnode) ? cpu_node : node;
87 		data = ((coremap | (route_node << 4)) << (data_byte * 8));
88 		csr_any_send(EIOINTC_REG_ROUTE + pos_off, data, data_mask, node * CORES_PER_EIO_NODE);
89 	}
90 }
91 
92 static DEFINE_RAW_SPINLOCK(affinity_lock);
93 
94 static int eiointc_set_irq_affinity(struct irq_data *d, const struct cpumask *affinity, bool force)
95 {
96 	unsigned int cpu;
97 	unsigned long flags;
98 	uint32_t vector, regaddr;
99 	struct eiointc_priv *priv = d->domain->host_data;
100 
101 	raw_spin_lock_irqsave(&affinity_lock, flags);
102 
103 	cpu = cpumask_first_and_and(&priv->cpuspan_map, affinity, cpu_online_mask);
104 	if (cpu >= nr_cpu_ids) {
105 		raw_spin_unlock_irqrestore(&affinity_lock, flags);
106 		return -EINVAL;
107 	}
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 #endif
130 
131 static int eiointc_index(int node)
132 {
133 	int i;
134 
135 	for (i = 0; i < nr_pics; i++) {
136 		if (node_isset(node, eiointc_priv[i]->node_map))
137 			return i;
138 	}
139 
140 	return -1;
141 }
142 
143 static int eiointc_router_init(unsigned int cpu)
144 {
145 	int i, bit;
146 	uint32_t data;
147 	uint32_t node = cpu_to_eio_node(cpu);
148 	int index = eiointc_index(node);
149 
150 	if (index < 0) {
151 		pr_err("Error: invalid nodemap!\n");
152 		return -1;
153 	}
154 
155 	if ((cpu_logical_map(cpu) % CORES_PER_EIO_NODE) == 0) {
156 		eiointc_enable();
157 
158 		for (i = 0; i < eiointc_priv[0]->vec_count / 32; i++) {
159 			data = (((1 << (i * 2 + 1)) << 16) | (1 << (i * 2)));
160 			iocsr_write32(data, EIOINTC_REG_NODEMAP + i * 4);
161 		}
162 
163 		for (i = 0; i < eiointc_priv[0]->vec_count / 32 / 4; i++) {
164 			bit = BIT(1 + index); /* Route to IP[1 + index] */
165 			data = bit | (bit << 8) | (bit << 16) | (bit << 24);
166 			iocsr_write32(data, EIOINTC_REG_IPMAP + i * 4);
167 		}
168 
169 		for (i = 0; i < eiointc_priv[0]->vec_count / 4; i++) {
170 			/* Route to Node-0 Core-0 */
171 			if (index == 0)
172 				bit = BIT(cpu_logical_map(0));
173 			else
174 				bit = (eiointc_priv[index]->node << 4) | 1;
175 
176 			data = bit | (bit << 8) | (bit << 16) | (bit << 24);
177 			iocsr_write32(data, EIOINTC_REG_ROUTE + i * 4);
178 		}
179 
180 		for (i = 0; i < eiointc_priv[0]->vec_count / 32; i++) {
181 			data = 0xffffffff;
182 			iocsr_write32(data, EIOINTC_REG_ENABLE + i * 4);
183 			iocsr_write32(data, EIOINTC_REG_BOUNCE + i * 4);
184 		}
185 	}
186 
187 	return 0;
188 }
189 
190 static void eiointc_irq_dispatch(struct irq_desc *desc)
191 {
192 	int i;
193 	u64 pending;
194 	bool handled = false;
195 	struct irq_chip *chip = irq_desc_get_chip(desc);
196 	struct eiointc_priv *priv = irq_desc_get_handler_data(desc);
197 
198 	chained_irq_enter(chip, desc);
199 
200 	for (i = 0; i < eiointc_priv[0]->vec_count / VEC_COUNT_PER_REG; i++) {
201 		pending = iocsr_read64(EIOINTC_REG_ISR + (i << 3));
202 
203 		/* Skip handling if pending bitmap is zero */
204 		if (!pending)
205 			continue;
206 
207 		/* Clear the IRQs */
208 		iocsr_write64(pending, EIOINTC_REG_ISR + (i << 3));
209 		while (pending) {
210 			int bit = __ffs(pending);
211 			int irq = bit + VEC_COUNT_PER_REG * i;
212 
213 			generic_handle_domain_irq(priv->eiointc_domain, irq);
214 			pending &= ~BIT(bit);
215 			handled = true;
216 		}
217 	}
218 
219 	if (!handled)
220 		spurious_interrupt();
221 
222 	chained_irq_exit(chip, desc);
223 }
224 
225 static void eiointc_ack_irq(struct irq_data *d)
226 {
227 }
228 
229 static void eiointc_mask_irq(struct irq_data *d)
230 {
231 }
232 
233 static void eiointc_unmask_irq(struct irq_data *d)
234 {
235 }
236 
237 static struct irq_chip eiointc_irq_chip = {
238 	.name			= "EIOINTC",
239 	.irq_ack		= eiointc_ack_irq,
240 	.irq_mask		= eiointc_mask_irq,
241 	.irq_unmask		= eiointc_unmask_irq,
242 #ifdef CONFIG_SMP
243 	.irq_set_affinity	= eiointc_set_irq_affinity,
244 #endif
245 };
246 
247 static int eiointc_domain_alloc(struct irq_domain *domain, unsigned int virq,
248 				unsigned int nr_irqs, void *arg)
249 {
250 	int ret;
251 	unsigned int i, type;
252 	unsigned long hwirq = 0;
253 	struct eiointc_priv *priv = domain->host_data;
254 
255 	ret = irq_domain_translate_onecell(domain, arg, &hwirq, &type);
256 	if (ret)
257 		return ret;
258 
259 	for (i = 0; i < nr_irqs; i++) {
260 		irq_domain_set_info(domain, virq + i, hwirq + i, &eiointc_irq_chip,
261 					priv, handle_edge_irq, NULL, NULL);
262 	}
263 
264 	return 0;
265 }
266 
267 static void eiointc_domain_free(struct irq_domain *domain, unsigned int virq,
268 				unsigned int nr_irqs)
269 {
270 	int i;
271 
272 	for (i = 0; i < nr_irqs; i++) {
273 		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
274 
275 		irq_set_handler(virq + i, NULL);
276 		irq_domain_reset_irq_data(d);
277 	}
278 }
279 
280 static const struct irq_domain_ops eiointc_domain_ops = {
281 	.translate	= irq_domain_translate_onecell,
282 	.alloc		= eiointc_domain_alloc,
283 	.free		= eiointc_domain_free,
284 };
285 
286 static void acpi_set_vec_parent(int node, struct irq_domain *parent, struct acpi_vector_group *vec_group)
287 {
288 	int i;
289 
290 	for (i = 0; i < MAX_IO_PICS; i++) {
291 		if (node == vec_group[i].node) {
292 			vec_group[i].parent = parent;
293 			return;
294 		}
295 	}
296 }
297 
298 static struct irq_domain *acpi_get_vec_parent(int node, struct acpi_vector_group *vec_group)
299 {
300 	int i;
301 
302 	for (i = 0; i < MAX_IO_PICS; i++) {
303 		if (node == vec_group[i].node)
304 			return vec_group[i].parent;
305 	}
306 	return NULL;
307 }
308 
309 static int eiointc_suspend(void)
310 {
311 	return 0;
312 }
313 
314 static void eiointc_resume(void)
315 {
316 	eiointc_router_init(0);
317 }
318 
319 static struct syscore_ops eiointc_syscore_ops = {
320 	.suspend = eiointc_suspend,
321 	.resume = eiointc_resume,
322 };
323 
324 static int __init pch_pic_parse_madt(union acpi_subtable_headers *header,
325 					const unsigned long end)
326 {
327 	struct acpi_madt_bio_pic *pchpic_entry = (struct acpi_madt_bio_pic *)header;
328 	unsigned int node = (pchpic_entry->address >> 44) & 0xf;
329 	struct irq_domain *parent = acpi_get_vec_parent(node, pch_group);
330 
331 	if (parent)
332 		return pch_pic_acpi_init(parent, pchpic_entry);
333 
334 	return 0;
335 }
336 
337 static int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
338 					const unsigned long end)
339 {
340 	struct irq_domain *parent;
341 	struct acpi_madt_msi_pic *pchmsi_entry = (struct acpi_madt_msi_pic *)header;
342 	int node;
343 
344 	if (cpu_has_flatmode)
345 		node = early_cpu_to_node(eiointc_priv[nr_pics - 1]->node * CORES_PER_EIO_NODE);
346 	else
347 		node = eiointc_priv[nr_pics - 1]->node;
348 
349 	parent = acpi_get_vec_parent(node, msi_group);
350 
351 	if (parent)
352 		return pch_msi_acpi_init(parent, pchmsi_entry);
353 
354 	return 0;
355 }
356 
357 static int __init acpi_cascade_irqdomain_init(void)
358 {
359 	int r;
360 
361 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_BIO_PIC, pch_pic_parse_madt, 0);
362 	if (r < 0)
363 		return r;
364 
365 	if (cpu_has_avecint)
366 		return 0;
367 
368 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_MSI_PIC, pch_msi_parse_madt, 1);
369 	if (r < 0)
370 		return r;
371 
372 	return 0;
373 }
374 
375 static int __init eiointc_init(struct eiointc_priv *priv, int parent_irq,
376 			       u64 node_map)
377 {
378 	int i;
379 
380 	node_map = node_map ? node_map : -1ULL;
381 	for_each_possible_cpu(i) {
382 		if (node_map & (1ULL << (cpu_to_eio_node(i)))) {
383 			node_set(cpu_to_eio_node(i), priv->node_map);
384 			cpumask_or(&priv->cpuspan_map, &priv->cpuspan_map,
385 				   cpumask_of(i));
386 		}
387 	}
388 
389 	priv->eiointc_domain = irq_domain_create_linear(priv->domain_handle,
390 							priv->vec_count,
391 							&eiointc_domain_ops,
392 							priv);
393 	if (!priv->eiointc_domain) {
394 		pr_err("loongson-extioi: cannot add IRQ domain\n");
395 		return -ENOMEM;
396 	}
397 
398 	eiointc_priv[nr_pics++] = priv;
399 	eiointc_router_init(0);
400 	irq_set_chained_handler_and_data(parent_irq, eiointc_irq_dispatch, priv);
401 
402 	if (nr_pics == 1) {
403 		register_syscore_ops(&eiointc_syscore_ops);
404 		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_EIOINTC_STARTING,
405 					  "irqchip/loongarch/eiointc:starting",
406 					  eiointc_router_init, NULL);
407 	}
408 
409 	return 0;
410 }
411 
412 int __init eiointc_acpi_init(struct irq_domain *parent,
413 				     struct acpi_madt_eio_pic *acpi_eiointc)
414 {
415 	int parent_irq, ret;
416 	struct eiointc_priv *priv;
417 	int node;
418 
419 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
420 	if (!priv)
421 		return -ENOMEM;
422 
423 	priv->domain_handle = irq_domain_alloc_named_id_fwnode("EIOPIC",
424 							       acpi_eiointc->node);
425 	if (!priv->domain_handle) {
426 		pr_err("Unable to allocate domain handle\n");
427 		goto out_free_priv;
428 	}
429 
430 	priv->vec_count = VEC_COUNT;
431 	priv->node = acpi_eiointc->node;
432 
433 	parent_irq = irq_create_mapping(parent, acpi_eiointc->cascade);
434 
435 	ret = eiointc_init(priv, parent_irq, acpi_eiointc->node_map);
436 	if (ret < 0)
437 		goto out_free_handle;
438 
439 	if (cpu_has_flatmode)
440 		node = early_cpu_to_node(acpi_eiointc->node * CORES_PER_EIO_NODE);
441 	else
442 		node = acpi_eiointc->node;
443 	acpi_set_vec_parent(node, priv->eiointc_domain, pch_group);
444 	acpi_set_vec_parent(node, priv->eiointc_domain, msi_group);
445 
446 	ret = acpi_cascade_irqdomain_init();
447 	if (ret < 0)
448 		goto out_free_handle;
449 
450 	return ret;
451 
452 out_free_handle:
453 	irq_domain_free_fwnode(priv->domain_handle);
454 	priv->domain_handle = NULL;
455 out_free_priv:
456 	kfree(priv);
457 
458 	return -ENOMEM;
459 }
460 
461 static int __init eiointc_of_init(struct device_node *of_node,
462 				  struct device_node *parent)
463 {
464 	int parent_irq, ret;
465 	struct eiointc_priv *priv;
466 
467 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
468 	if (!priv)
469 		return -ENOMEM;
470 
471 	parent_irq = irq_of_parse_and_map(of_node, 0);
472 	if (parent_irq <= 0) {
473 		ret = -ENODEV;
474 		goto out_free_priv;
475 	}
476 
477 	ret = irq_set_handler_data(parent_irq, priv);
478 	if (ret < 0)
479 		goto out_free_priv;
480 
481 	/*
482 	 * In particular, the number of devices supported by the LS2K0500
483 	 * extended I/O interrupt vector is 128.
484 	 */
485 	if (of_device_is_compatible(of_node, "loongson,ls2k0500-eiointc"))
486 		priv->vec_count = 128;
487 	else
488 		priv->vec_count = VEC_COUNT;
489 
490 	priv->node = 0;
491 	priv->domain_handle = of_node_to_fwnode(of_node);
492 
493 	ret = eiointc_init(priv, parent_irq, 0);
494 	if (ret < 0)
495 		goto out_free_priv;
496 
497 	return 0;
498 
499 out_free_priv:
500 	kfree(priv);
501 	return ret;
502 }
503 
504 IRQCHIP_DECLARE(loongson_ls2k0500_eiointc, "loongson,ls2k0500-eiointc", eiointc_of_init);
505 IRQCHIP_DECLARE(loongson_ls2k2000_eiointc, "loongson,ls2k2000-eiointc", eiointc_of_init);
506