xref: /linux/drivers/acpi/riscv/irq.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2023-2024, Ventana Micro Systems Inc
4  *	Author: Sunil V L <sunilvl@ventanamicro.com>
5  */
6 
7 #include <linux/acpi.h>
8 #include <linux/sort.h>
9 #include <linux/irq.h>
10 
11 #include "init.h"
12 
13 #define RISCV_ACPI_INTC_FLAG_PENDING BIT(0)
14 
15 struct riscv_ext_intc_list {
16 	acpi_handle		handle;
17 	u32			gsi_base;
18 	u32			nr_irqs;
19 	u32			nr_idcs;
20 	u32			id;
21 	u32			type;
22 	u32			flag;
23 	struct list_head	list;
24 };
25 
26 struct acpi_irq_dep_ctx {
27 	int		rc;
28 	unsigned int	index;
29 	acpi_handle	handle;
30 };
31 
32 LIST_HEAD(ext_intc_list);
33 
34 static int irqchip_cmp_func(const void *in0, const void *in1)
35 {
36 	struct acpi_probe_entry *elem0 = (struct acpi_probe_entry *)in0;
37 	struct acpi_probe_entry *elem1 = (struct acpi_probe_entry *)in1;
38 
39 	return (elem0->type > elem1->type) - (elem0->type < elem1->type);
40 }
41 
42 /*
43  * On RISC-V, RINTC structures in MADT should be probed before any other
44  * interrupt controller structures and IMSIC before APLIC. The interrupt
45  * controller subtypes in MADT of ACPI spec for RISC-V are defined in
46  * the incremental order like RINTC(24)->IMSIC(25)->APLIC(26)->PLIC(27).
47  * Hence, simply sorting the subtypes in incremental order will
48  * establish the required order.
49  */
50 void arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr)
51 {
52 	struct acpi_probe_entry *ape = ap_head;
53 
54 	if (nr == 1 || !ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id))
55 		return;
56 	sort(ape, nr, sizeof(*ape), irqchip_cmp_func, NULL);
57 }
58 
59 static acpi_status riscv_acpi_update_gsi_handle(u32 gsi_base, acpi_handle handle)
60 {
61 	struct riscv_ext_intc_list *ext_intc_element;
62 	struct list_head *i, *tmp;
63 
64 	list_for_each_safe(i, tmp, &ext_intc_list) {
65 		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
66 		if (gsi_base == ext_intc_element->gsi_base) {
67 			ext_intc_element->handle = handle;
68 			return AE_OK;
69 		}
70 	}
71 
72 	return AE_NOT_FOUND;
73 }
74 
75 int riscv_acpi_update_gsi_range(u32 gsi_base, u32 nr_irqs)
76 {
77 	struct riscv_ext_intc_list *ext_intc_element;
78 
79 	list_for_each_entry(ext_intc_element, &ext_intc_list, list) {
80 		if (gsi_base == ext_intc_element->gsi_base &&
81 		    (ext_intc_element->flag & RISCV_ACPI_INTC_FLAG_PENDING)) {
82 			ext_intc_element->nr_irqs = nr_irqs;
83 			ext_intc_element->flag &= ~RISCV_ACPI_INTC_FLAG_PENDING;
84 			return 0;
85 		}
86 	}
87 
88 	return -ENODEV;
89 }
90 
91 int riscv_acpi_get_gsi_info(struct fwnode_handle *fwnode, u32 *gsi_base,
92 			    u32 *id, u32 *nr_irqs, u32 *nr_idcs)
93 {
94 	struct riscv_ext_intc_list *ext_intc_element;
95 	struct list_head *i;
96 
97 	list_for_each(i, &ext_intc_list) {
98 		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
99 		if (ext_intc_element->handle == ACPI_HANDLE_FWNODE(fwnode)) {
100 			*gsi_base = ext_intc_element->gsi_base;
101 			*id = ext_intc_element->id;
102 			*nr_irqs = ext_intc_element->nr_irqs;
103 			if (nr_idcs)
104 				*nr_idcs = ext_intc_element->nr_idcs;
105 
106 			return 0;
107 		}
108 	}
109 
110 	return -ENODEV;
111 }
112 
113 struct fwnode_handle *riscv_acpi_get_gsi_domain_id(u32 gsi)
114 {
115 	struct riscv_ext_intc_list *ext_intc_element;
116 	struct acpi_device *adev;
117 	struct list_head *i;
118 
119 	list_for_each(i, &ext_intc_list) {
120 		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
121 		if (gsi >= ext_intc_element->gsi_base &&
122 		    gsi < (ext_intc_element->gsi_base + ext_intc_element->nr_irqs)) {
123 			adev = acpi_fetch_acpi_dev(ext_intc_element->handle);
124 			if (!adev)
125 				return NULL;
126 
127 			return acpi_fwnode_handle(adev);
128 		}
129 	}
130 
131 	return NULL;
132 }
133 
134 static int __init riscv_acpi_register_ext_intc(u32 gsi_base, u32 nr_irqs, u32 nr_idcs,
135 					       u32 id, u32 type)
136 {
137 	struct riscv_ext_intc_list *ext_intc_element, *node, *prev;
138 
139 	ext_intc_element = kzalloc(sizeof(*ext_intc_element), GFP_KERNEL);
140 	if (!ext_intc_element)
141 		return -ENOMEM;
142 
143 	ext_intc_element->gsi_base = gsi_base;
144 
145 	/* If nr_irqs is zero, indicate it in flag and set to max range possible */
146 	if (nr_irqs) {
147 		ext_intc_element->nr_irqs = nr_irqs;
148 	} else {
149 		ext_intc_element->flag |= RISCV_ACPI_INTC_FLAG_PENDING;
150 		ext_intc_element->nr_irqs = U32_MAX - ext_intc_element->gsi_base;
151 	}
152 
153 	ext_intc_element->nr_idcs = nr_idcs;
154 	ext_intc_element->id = id;
155 	list_for_each_entry(node, &ext_intc_list, list) {
156 		if (node->gsi_base < ext_intc_element->gsi_base)
157 			break;
158 	}
159 
160 	/* Adjust the previous node's GSI range if that has pending registration */
161 	prev = list_prev_entry(node, list);
162 	if (!list_entry_is_head(prev, &ext_intc_list, list)) {
163 		if (prev->flag & RISCV_ACPI_INTC_FLAG_PENDING)
164 			prev->nr_irqs = ext_intc_element->gsi_base - prev->gsi_base;
165 	}
166 
167 	list_add_tail(&ext_intc_element->list, &node->list);
168 	return 0;
169 }
170 
171 static acpi_status __init riscv_acpi_create_gsi_map_smsi(acpi_handle handle, u32 level,
172 							 void *context, void **return_value)
173 {
174 	acpi_status status;
175 	u64 gbase;
176 
177 	if (!acpi_has_method(handle, "_GSB")) {
178 		acpi_handle_err(handle, "_GSB method not found\n");
179 		return AE_ERROR;
180 	}
181 
182 	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gbase);
183 	if (ACPI_FAILURE(status)) {
184 		acpi_handle_err(handle, "failed to evaluate _GSB method\n");
185 		return status;
186 	}
187 
188 	riscv_acpi_register_ext_intc(gbase, 0, 0, 0, ACPI_RISCV_IRQCHIP_SMSI);
189 	status = riscv_acpi_update_gsi_handle((u32)gbase, handle);
190 	if (ACPI_FAILURE(status)) {
191 		acpi_handle_err(handle, "failed to find the GSI mapping entry\n");
192 		return status;
193 	}
194 
195 	return AE_OK;
196 }
197 
198 static acpi_status __init riscv_acpi_create_gsi_map(acpi_handle handle, u32 level,
199 						    void *context, void **return_value)
200 {
201 	acpi_status status;
202 	u64 gbase;
203 
204 	if (!acpi_has_method(handle, "_GSB")) {
205 		acpi_handle_err(handle, "_GSB method not found\n");
206 		return AE_ERROR;
207 	}
208 
209 	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gbase);
210 	if (ACPI_FAILURE(status)) {
211 		acpi_handle_err(handle, "failed to evaluate _GSB method\n");
212 		return status;
213 	}
214 
215 	status = riscv_acpi_update_gsi_handle((u32)gbase, handle);
216 	if (ACPI_FAILURE(status)) {
217 		acpi_handle_err(handle, "failed to find the GSI mapping entry\n");
218 		return status;
219 	}
220 
221 	return AE_OK;
222 }
223 
224 static int __init riscv_acpi_aplic_parse_madt(union acpi_subtable_headers *header,
225 					      const unsigned long end)
226 {
227 	struct acpi_madt_aplic *aplic = (struct acpi_madt_aplic *)header;
228 
229 	return riscv_acpi_register_ext_intc(aplic->gsi_base, aplic->num_sources, aplic->num_idcs,
230 					    aplic->id, ACPI_RISCV_IRQCHIP_APLIC);
231 }
232 
233 static int __init riscv_acpi_plic_parse_madt(union acpi_subtable_headers *header,
234 					     const unsigned long end)
235 {
236 	struct acpi_madt_plic *plic = (struct acpi_madt_plic *)header;
237 
238 	return riscv_acpi_register_ext_intc(plic->gsi_base, plic->num_irqs, 0,
239 					    plic->id, ACPI_RISCV_IRQCHIP_PLIC);
240 }
241 
242 void __init riscv_acpi_init_gsi_mapping(void)
243 {
244 	/* There can be either PLIC or APLIC */
245 	if (acpi_table_parse_madt(ACPI_MADT_TYPE_PLIC, riscv_acpi_plic_parse_madt, 0) > 0) {
246 		acpi_get_devices("RSCV0001", riscv_acpi_create_gsi_map, NULL, NULL);
247 		return;
248 	}
249 
250 	if (acpi_table_parse_madt(ACPI_MADT_TYPE_APLIC, riscv_acpi_aplic_parse_madt, 0) > 0)
251 		acpi_get_devices("RSCV0002", riscv_acpi_create_gsi_map, NULL, NULL);
252 
253 	/* Unlike PLIC/APLIC, SYSMSI doesn't have MADT */
254 	acpi_get_devices("RSCV0006", riscv_acpi_create_gsi_map_smsi, NULL, NULL);
255 }
256 
257 static acpi_handle riscv_acpi_get_gsi_handle(u32 gsi)
258 {
259 	struct riscv_ext_intc_list *ext_intc_element;
260 	struct list_head *i;
261 
262 	list_for_each(i, &ext_intc_list) {
263 		ext_intc_element = list_entry(i, struct riscv_ext_intc_list, list);
264 		if (gsi >= ext_intc_element->gsi_base &&
265 		    gsi < (ext_intc_element->gsi_base + ext_intc_element->nr_irqs))
266 			return ext_intc_element->handle;
267 	}
268 
269 	return NULL;
270 }
271 
272 static acpi_status riscv_acpi_irq_get_parent(struct acpi_resource *ares, void *context)
273 {
274 	struct acpi_irq_dep_ctx *ctx = context;
275 	struct acpi_resource_irq *irq;
276 	struct acpi_resource_extended_irq *eirq;
277 
278 	switch (ares->type) {
279 	case ACPI_RESOURCE_TYPE_IRQ:
280 		irq = &ares->data.irq;
281 		if (ctx->index >= irq->interrupt_count) {
282 			ctx->index -= irq->interrupt_count;
283 			return AE_OK;
284 		}
285 		ctx->handle = riscv_acpi_get_gsi_handle(irq->interrupts[ctx->index]);
286 		return AE_CTRL_TERMINATE;
287 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
288 		eirq = &ares->data.extended_irq;
289 		if (eirq->producer_consumer == ACPI_PRODUCER)
290 			return AE_OK;
291 
292 		if (ctx->index >= eirq->interrupt_count) {
293 			ctx->index -= eirq->interrupt_count;
294 			return AE_OK;
295 		}
296 
297 		/* Support GSIs only */
298 		if (eirq->resource_source.string_length)
299 			return AE_OK;
300 
301 		ctx->handle = riscv_acpi_get_gsi_handle(eirq->interrupts[ctx->index]);
302 		return AE_CTRL_TERMINATE;
303 	}
304 
305 	return AE_OK;
306 }
307 
308 static int riscv_acpi_irq_get_dep(acpi_handle handle, unsigned int index, acpi_handle *gsi_handle)
309 {
310 	struct acpi_irq_dep_ctx ctx = {-EINVAL, index, NULL};
311 
312 	if (!gsi_handle)
313 		return 0;
314 
315 	acpi_walk_resources(handle, METHOD_NAME__CRS, riscv_acpi_irq_get_parent, &ctx);
316 	*gsi_handle = ctx.handle;
317 	if (*gsi_handle)
318 		return 1;
319 
320 	return 0;
321 }
322 
323 static u32 riscv_acpi_add_prt_dep(acpi_handle handle)
324 {
325 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
326 	struct acpi_pci_routing_table *entry;
327 	struct acpi_handle_list dep_devices;
328 	acpi_handle gsi_handle;
329 	acpi_handle link_handle;
330 	acpi_status status;
331 	u32 count = 0;
332 
333 	status = acpi_get_irq_routing_table(handle, &buffer);
334 	if (ACPI_FAILURE(status)) {
335 		acpi_handle_err(handle, "failed to get IRQ routing table\n");
336 		kfree(buffer.pointer);
337 		return 0;
338 	}
339 
340 	entry = buffer.pointer;
341 	while (entry && (entry->length > 0)) {
342 		if (entry->source[0]) {
343 			acpi_get_handle(handle, entry->source, &link_handle);
344 			dep_devices.count = 1;
345 			dep_devices.handles = kcalloc(1, sizeof(*dep_devices.handles), GFP_KERNEL);
346 			if (!dep_devices.handles) {
347 				acpi_handle_err(handle, "failed to allocate memory\n");
348 				continue;
349 			}
350 
351 			dep_devices.handles[0] = link_handle;
352 			count += acpi_scan_add_dep(handle, &dep_devices);
353 		} else {
354 			gsi_handle = riscv_acpi_get_gsi_handle(entry->source_index);
355 			dep_devices.count = 1;
356 			dep_devices.handles = kcalloc(1, sizeof(*dep_devices.handles), GFP_KERNEL);
357 			if (!dep_devices.handles) {
358 				acpi_handle_err(handle, "failed to allocate memory\n");
359 				continue;
360 			}
361 
362 			dep_devices.handles[0] = gsi_handle;
363 			count += acpi_scan_add_dep(handle, &dep_devices);
364 		}
365 
366 		entry = (struct acpi_pci_routing_table *)
367 			((unsigned long)entry + entry->length);
368 	}
369 
370 	kfree(buffer.pointer);
371 	return count;
372 }
373 
374 static u32 riscv_acpi_add_irq_dep(acpi_handle handle)
375 {
376 	struct acpi_handle_list dep_devices;
377 	acpi_handle gsi_handle;
378 	u32 count = 0;
379 	int i;
380 
381 	for (i = 0;
382 	     riscv_acpi_irq_get_dep(handle, i, &gsi_handle);
383 	     i++) {
384 		dep_devices.count = 1;
385 		dep_devices.handles = kcalloc(1, sizeof(*dep_devices.handles), GFP_KERNEL);
386 		if (!dep_devices.handles) {
387 			acpi_handle_err(handle, "failed to allocate memory\n");
388 			continue;
389 		}
390 
391 		dep_devices.handles[0] = gsi_handle;
392 		count += acpi_scan_add_dep(handle, &dep_devices);
393 	}
394 
395 	return count;
396 }
397 
398 u32 arch_acpi_add_auto_dep(acpi_handle handle)
399 {
400 	if (acpi_has_method(handle, "_PRT"))
401 		return riscv_acpi_add_prt_dep(handle);
402 
403 	return riscv_acpi_add_irq_dep(handle);
404 }
405