xref: /linux/drivers/irqchip/irq-loongson-eiointc.c (revision 0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b)
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/interrupt.h>
11 #include <linux/irq.h>
12 #include <linux/irqchip.h>
13 #include <linux/irqdomain.h>
14 #include <linux/irqchip/chained_irq.h>
15 #include <linux/kernel.h>
16 #include <linux/platform_device.h>
17 #include <linux/of_address.h>
18 #include <linux/of_irq.h>
19 #include <linux/of_platform.h>
20 #include <linux/syscore_ops.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 	nodemask_t		node_map;
43 	cpumask_t		cpuspan_map;
44 	struct fwnode_handle	*domain_handle;
45 	struct irq_domain	*eiointc_domain;
46 };
47 
48 static struct eiointc_priv *eiointc_priv[MAX_IO_PICS];
49 
50 static void eiointc_enable(void)
51 {
52 	uint64_t misc;
53 
54 	misc = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
55 	misc |= IOCSR_MISC_FUNC_EXT_IOI_EN;
56 	iocsr_write64(misc, LOONGARCH_IOCSR_MISC_FUNC);
57 }
58 
59 static int cpu_to_eio_node(int cpu)
60 {
61 	return cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
62 }
63 
64 static void eiointc_set_irq_route(int pos, unsigned int cpu, unsigned int mnode, nodemask_t *node_map)
65 {
66 	int i, node, cpu_node, route_node;
67 	unsigned char coremap;
68 	uint32_t pos_off, data, data_byte, data_mask;
69 
70 	pos_off = pos & ~3;
71 	data_byte = pos & 3;
72 	data_mask = ~BIT_MASK(data_byte) & 0xf;
73 
74 	/* Calculate node and coremap of target irq */
75 	cpu_node = cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
76 	coremap = BIT(cpu_logical_map(cpu) % CORES_PER_EIO_NODE);
77 
78 	for_each_online_cpu(i) {
79 		node = cpu_to_eio_node(i);
80 		if (!node_isset(node, *node_map))
81 			continue;
82 
83 		/* EIO node 0 is in charge of inter-node interrupt dispatch */
84 		route_node = (node == mnode) ? cpu_node : node;
85 		data = ((coremap | (route_node << 4)) << (data_byte * 8));
86 		csr_any_send(EIOINTC_REG_ROUTE + pos_off, data, data_mask, node * CORES_PER_EIO_NODE);
87 	}
88 }
89 
90 static DEFINE_RAW_SPINLOCK(affinity_lock);
91 
92 static int eiointc_set_irq_affinity(struct irq_data *d, const struct cpumask *affinity, bool force)
93 {
94 	unsigned int cpu;
95 	unsigned long flags;
96 	uint32_t vector, regaddr;
97 	struct cpumask intersect_affinity;
98 	struct eiointc_priv *priv = d->domain->host_data;
99 
100 	raw_spin_lock_irqsave(&affinity_lock, flags);
101 
102 	cpumask_and(&intersect_affinity, affinity, cpu_online_mask);
103 	cpumask_and(&intersect_affinity, &intersect_affinity, &priv->cpuspan_map);
104 
105 	if (cpumask_empty(&intersect_affinity)) {
106 		raw_spin_unlock_irqrestore(&affinity_lock, flags);
107 		return -EINVAL;
108 	}
109 	cpu = cpumask_first(&intersect_affinity);
110 
111 	vector = d->hwirq;
112 	regaddr = EIOINTC_REG_ENABLE + ((vector >> 5) << 2);
113 
114 	/* Mask target vector */
115 	csr_any_send(regaddr, EIOINTC_ALL_ENABLE & (~BIT(vector & 0x1F)),
116 			0x0, priv->node * CORES_PER_EIO_NODE);
117 
118 	/* Set route for target vector */
119 	eiointc_set_irq_route(vector, cpu, priv->node, &priv->node_map);
120 
121 	/* Unmask target vector */
122 	csr_any_send(regaddr, EIOINTC_ALL_ENABLE,
123 			0x0, priv->node * CORES_PER_EIO_NODE);
124 
125 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
126 
127 	raw_spin_unlock_irqrestore(&affinity_lock, flags);
128 
129 	return IRQ_SET_MASK_OK;
130 }
131 
132 static int eiointc_index(int node)
133 {
134 	int i;
135 
136 	for (i = 0; i < nr_pics; i++) {
137 		if (node_isset(node, eiointc_priv[i]->node_map))
138 			return i;
139 	}
140 
141 	return -1;
142 }
143 
144 static int eiointc_router_init(unsigned int cpu)
145 {
146 	int i, bit;
147 	uint32_t data;
148 	uint32_t node = cpu_to_eio_node(cpu);
149 	uint32_t index = eiointc_index(node);
150 
151 	if (index < 0) {
152 		pr_err("Error: invalid nodemap!\n");
153 		return -1;
154 	}
155 
156 	if ((cpu_logical_map(cpu) % CORES_PER_EIO_NODE) == 0) {
157 		eiointc_enable();
158 
159 		for (i = 0; i < VEC_COUNT / 32; i++) {
160 			data = (((1 << (i * 2 + 1)) << 16) | (1 << (i * 2)));
161 			iocsr_write32(data, EIOINTC_REG_NODEMAP + i * 4);
162 		}
163 
164 		for (i = 0; i < VEC_COUNT / 32 / 4; i++) {
165 			bit = BIT(1 + index); /* Route to IP[1 + index] */
166 			data = bit | (bit << 8) | (bit << 16) | (bit << 24);
167 			iocsr_write32(data, EIOINTC_REG_IPMAP + i * 4);
168 		}
169 
170 		for (i = 0; i < VEC_COUNT / 4; i++) {
171 			/* Route to Node-0 Core-0 */
172 			if (index == 0)
173 				bit = BIT(cpu_logical_map(0));
174 			else
175 				bit = (eiointc_priv[index]->node << 4) | 1;
176 
177 			data = bit | (bit << 8) | (bit << 16) | (bit << 24);
178 			iocsr_write32(data, EIOINTC_REG_ROUTE + i * 4);
179 		}
180 
181 		for (i = 0; i < VEC_COUNT / 32; i++) {
182 			data = 0xffffffff;
183 			iocsr_write32(data, EIOINTC_REG_ENABLE + i * 4);
184 			iocsr_write32(data, EIOINTC_REG_BOUNCE + i * 4);
185 		}
186 	}
187 
188 	return 0;
189 }
190 
191 static void eiointc_irq_dispatch(struct irq_desc *desc)
192 {
193 	int i;
194 	u64 pending;
195 	bool handled = false;
196 	struct irq_chip *chip = irq_desc_get_chip(desc);
197 	struct eiointc_priv *priv = irq_desc_get_handler_data(desc);
198 
199 	chained_irq_enter(chip, desc);
200 
201 	for (i = 0; i < VEC_REG_COUNT; i++) {
202 		pending = iocsr_read64(EIOINTC_REG_ISR + (i << 3));
203 		iocsr_write64(pending, EIOINTC_REG_ISR + (i << 3));
204 		while (pending) {
205 			int bit = __ffs(pending);
206 			int irq = bit + VEC_COUNT_PER_REG * i;
207 
208 			generic_handle_domain_irq(priv->eiointc_domain, irq);
209 			pending &= ~BIT(bit);
210 			handled = true;
211 		}
212 	}
213 
214 	if (!handled)
215 		spurious_interrupt();
216 
217 	chained_irq_exit(chip, desc);
218 }
219 
220 static void eiointc_ack_irq(struct irq_data *d)
221 {
222 }
223 
224 static void eiointc_mask_irq(struct irq_data *d)
225 {
226 }
227 
228 static void eiointc_unmask_irq(struct irq_data *d)
229 {
230 }
231 
232 static struct irq_chip eiointc_irq_chip = {
233 	.name			= "EIOINTC",
234 	.irq_ack		= eiointc_ack_irq,
235 	.irq_mask		= eiointc_mask_irq,
236 	.irq_unmask		= eiointc_unmask_irq,
237 	.irq_set_affinity	= eiointc_set_irq_affinity,
238 };
239 
240 static int eiointc_domain_alloc(struct irq_domain *domain, unsigned int virq,
241 				unsigned int nr_irqs, void *arg)
242 {
243 	int ret;
244 	unsigned int i, type;
245 	unsigned long hwirq = 0;
246 	struct eiointc *priv = domain->host_data;
247 
248 	ret = irq_domain_translate_onecell(domain, arg, &hwirq, &type);
249 	if (ret)
250 		return ret;
251 
252 	for (i = 0; i < nr_irqs; i++) {
253 		irq_domain_set_info(domain, virq + i, hwirq + i, &eiointc_irq_chip,
254 					priv, handle_edge_irq, NULL, NULL);
255 	}
256 
257 	return 0;
258 }
259 
260 static void eiointc_domain_free(struct irq_domain *domain, unsigned int virq,
261 				unsigned int nr_irqs)
262 {
263 	int i;
264 
265 	for (i = 0; i < nr_irqs; i++) {
266 		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
267 
268 		irq_set_handler(virq + i, NULL);
269 		irq_domain_reset_irq_data(d);
270 	}
271 }
272 
273 static const struct irq_domain_ops eiointc_domain_ops = {
274 	.translate	= irq_domain_translate_onecell,
275 	.alloc		= eiointc_domain_alloc,
276 	.free		= eiointc_domain_free,
277 };
278 
279 static void acpi_set_vec_parent(int node, struct irq_domain *parent, struct acpi_vector_group *vec_group)
280 {
281 	int i;
282 
283 	if (cpu_has_flatmode)
284 		node = cpu_to_node(node * CORES_PER_EIO_NODE);
285 
286 	for (i = 0; i < MAX_IO_PICS; i++) {
287 		if (node == vec_group[i].node) {
288 			vec_group[i].parent = parent;
289 			return;
290 		}
291 	}
292 }
293 
294 static struct irq_domain *acpi_get_vec_parent(int node, struct acpi_vector_group *vec_group)
295 {
296 	int i;
297 
298 	for (i = 0; i < MAX_IO_PICS; i++) {
299 		if (node == vec_group[i].node)
300 			return vec_group[i].parent;
301 	}
302 	return NULL;
303 }
304 
305 static int eiointc_suspend(void)
306 {
307 	return 0;
308 }
309 
310 static void eiointc_resume(void)
311 {
312 	int i, j;
313 	struct irq_desc *desc;
314 	struct irq_data *irq_data;
315 
316 	eiointc_router_init(0);
317 
318 	for (i = 0; i < nr_pics; i++) {
319 		for (j = 0; j < VEC_COUNT; j++) {
320 			desc = irq_resolve_mapping(eiointc_priv[i]->eiointc_domain, j);
321 			if (desc && desc->handle_irq && desc->handle_irq != handle_bad_irq) {
322 				raw_spin_lock(&desc->lock);
323 				irq_data = &desc->irq_data;
324 				eiointc_set_irq_affinity(irq_data, irq_data->common->affinity, 0);
325 				raw_spin_unlock(&desc->lock);
326 			}
327 		}
328 	}
329 }
330 
331 static struct syscore_ops eiointc_syscore_ops = {
332 	.suspend = eiointc_suspend,
333 	.resume = eiointc_resume,
334 };
335 
336 static int __init pch_pic_parse_madt(union acpi_subtable_headers *header,
337 					const unsigned long end)
338 {
339 	struct acpi_madt_bio_pic *pchpic_entry = (struct acpi_madt_bio_pic *)header;
340 	unsigned int node = (pchpic_entry->address >> 44) & 0xf;
341 	struct irq_domain *parent = acpi_get_vec_parent(node, pch_group);
342 
343 	if (parent)
344 		return pch_pic_acpi_init(parent, pchpic_entry);
345 
346 	return -EINVAL;
347 }
348 
349 static int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
350 					const unsigned long end)
351 {
352 	struct acpi_madt_msi_pic *pchmsi_entry = (struct acpi_madt_msi_pic *)header;
353 	struct irq_domain *parent = acpi_get_vec_parent(eiointc_priv[nr_pics - 1]->node, msi_group);
354 
355 	if (parent)
356 		return pch_msi_acpi_init(parent, pchmsi_entry);
357 
358 	return -EINVAL;
359 }
360 
361 static int __init acpi_cascade_irqdomain_init(void)
362 {
363 	int r;
364 
365 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_BIO_PIC, pch_pic_parse_madt, 0);
366 	if (r < 0)
367 		return r;
368 
369 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_MSI_PIC, pch_msi_parse_madt, 1);
370 	if (r < 0)
371 		return r;
372 
373 	return 0;
374 }
375 
376 int __init eiointc_acpi_init(struct irq_domain *parent,
377 				     struct acpi_madt_eio_pic *acpi_eiointc)
378 {
379 	int i, ret, parent_irq;
380 	unsigned long node_map;
381 	struct eiointc_priv *priv;
382 
383 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
384 	if (!priv)
385 		return -ENOMEM;
386 
387 	priv->domain_handle = irq_domain_alloc_named_id_fwnode("EIOPIC",
388 							       acpi_eiointc->node);
389 	if (!priv->domain_handle) {
390 		pr_err("Unable to allocate domain handle\n");
391 		goto out_free_priv;
392 	}
393 
394 	priv->node = acpi_eiointc->node;
395 	node_map = acpi_eiointc->node_map ? : -1ULL;
396 
397 	for_each_possible_cpu(i) {
398 		if (node_map & (1ULL << cpu_to_eio_node(i))) {
399 			node_set(cpu_to_eio_node(i), priv->node_map);
400 			cpumask_or(&priv->cpuspan_map, &priv->cpuspan_map, cpumask_of(i));
401 		}
402 	}
403 
404 	/* Setup IRQ domain */
405 	priv->eiointc_domain = irq_domain_create_linear(priv->domain_handle, VEC_COUNT,
406 					&eiointc_domain_ops, priv);
407 	if (!priv->eiointc_domain) {
408 		pr_err("loongson-eiointc: cannot add IRQ domain\n");
409 		goto out_free_handle;
410 	}
411 
412 	eiointc_priv[nr_pics++] = priv;
413 
414 	eiointc_router_init(0);
415 
416 	parent_irq = irq_create_mapping(parent, acpi_eiointc->cascade);
417 	irq_set_chained_handler_and_data(parent_irq, eiointc_irq_dispatch, priv);
418 
419 	register_syscore_ops(&eiointc_syscore_ops);
420 	cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_LOONGARCH_STARTING,
421 				  "irqchip/loongarch/intc:starting",
422 				  eiointc_router_init, NULL);
423 
424 	acpi_set_vec_parent(acpi_eiointc->node, priv->eiointc_domain, pch_group);
425 	acpi_set_vec_parent(acpi_eiointc->node, priv->eiointc_domain, msi_group);
426 	ret = acpi_cascade_irqdomain_init();
427 
428 	return ret;
429 
430 out_free_handle:
431 	irq_domain_free_fwnode(priv->domain_handle);
432 	priv->domain_handle = NULL;
433 out_free_priv:
434 	kfree(priv);
435 
436 	return -ENOMEM;
437 }
438