1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ACPI GSI IRQ layer
4 *
5 * Copyright (C) 2015 ARM Ltd.
6 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
7 */
8#include <linux/acpi.h>
9#include <linux/irq.h>
10#include <linux/irqdomain.h>
11#include <linux/of.h>
12
13enum acpi_irq_model_id acpi_irq_model;
14
15static struct fwnode_handle *(*acpi_get_gsi_domain_id)(u32 gsi);
16static u32 (*acpi_gsi_to_irq_fallback)(u32 gsi);
17
18/**
19 * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
20 * @gsi: GSI IRQ number to map
21 * @irq: pointer where linux IRQ number is stored
22 *
23 * irq location updated with irq value [>0 on success, 0 on failure]
24 *
25 * Returns: 0 on success
26 * -EINVAL on failure
27 */
28int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
29{
30 struct irq_domain *d;
31
32 d = irq_find_matching_fwnode(fwnode: acpi_get_gsi_domain_id(gsi),
33 bus_token: DOMAIN_BUS_ANY);
34 *irq = irq_find_mapping(domain: d, hwirq: gsi);
35 /*
36 * *irq == 0 means no mapping, that should be reported as a
37 * failure, unless there is an arch-specific fallback handler.
38 */
39 if (!*irq && acpi_gsi_to_irq_fallback)
40 *irq = acpi_gsi_to_irq_fallback(gsi);
41
42 return (*irq > 0) ? 0 : -EINVAL;
43}
44EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
45
46/**
47 * acpi_register_gsi() - Map a GSI to a linux IRQ number
48 * @dev: device for which IRQ has to be mapped
49 * @gsi: GSI IRQ number
50 * @trigger: trigger type of the GSI number to be mapped
51 * @polarity: polarity of the GSI to be mapped
52 *
53 * Returns: a valid linux IRQ number on success
54 * -EINVAL on failure
55 */
56int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
57 int polarity)
58{
59 struct irq_fwspec fwspec;
60 unsigned int irq;
61
62 fwspec.fwnode = acpi_get_gsi_domain_id(gsi);
63 if (WARN_ON(!fwspec.fwnode)) {
64 pr_warn("GSI: No registered irqchip, giving up\n");
65 return -EINVAL;
66 }
67
68 fwspec.param[0] = gsi;
69 fwspec.param[1] = acpi_dev_get_irq_type(triggering: trigger, polarity);
70 fwspec.param_count = 2;
71
72 irq = irq_create_fwspec_mapping(fwspec: &fwspec);
73 if (!irq)
74 return -EINVAL;
75
76 return irq;
77}
78EXPORT_SYMBOL_GPL(acpi_register_gsi);
79
80/**
81 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
82 * @gsi: GSI IRQ number
83 */
84void acpi_unregister_gsi(u32 gsi)
85{
86 struct irq_domain *d;
87 int irq;
88
89 if (WARN_ON(acpi_irq_model == ACPI_IRQ_MODEL_GIC && gsi < 16))
90 return;
91
92 d = irq_find_matching_fwnode(fwnode: acpi_get_gsi_domain_id(gsi),
93 bus_token: DOMAIN_BUS_ANY);
94 irq = irq_find_mapping(domain: d, hwirq: gsi);
95 irq_dispose_mapping(virq: irq);
96}
97EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
98
99/**
100 * acpi_get_irq_source_fwhandle() - Retrieve fwhandle from IRQ resource source.
101 * @source: acpi_resource_source to use for the lookup.
102 * @gsi: GSI IRQ number
103 *
104 * Description:
105 * Retrieve the fwhandle of the device referenced by the given IRQ resource
106 * source.
107 *
108 * Return:
109 * The referenced device fwhandle or NULL on failure
110 */
111static struct fwnode_handle *
112acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source,
113 u32 gsi)
114{
115 struct fwnode_handle *result;
116 struct acpi_device *device;
117 acpi_handle handle;
118 acpi_status status;
119
120 if (!source->string_length)
121 return acpi_get_gsi_domain_id(gsi);
122
123 status = acpi_get_handle(NULL, pathname: source->string_ptr, ret_handle: &handle);
124 if (WARN_ON(ACPI_FAILURE(status)))
125 return NULL;
126
127 device = acpi_get_acpi_dev(handle);
128 if (WARN_ON(!device))
129 return NULL;
130
131 result = &device->fwnode;
132 acpi_put_acpi_dev(adev: device);
133 return result;
134}
135
136/*
137 * Context for the resource walk used to lookup IRQ resources.
138 * Contains a return code, the lookup index, and references to the flags
139 * and fwspec where the result is returned.
140 */
141struct acpi_irq_parse_one_ctx {
142 int rc;
143 unsigned int index;
144 unsigned long *res_flags;
145 struct irq_fwspec *fwspec;
146};
147
148/**
149 * acpi_irq_parse_one_match - Handle a matching IRQ resource.
150 * @fwnode: matching fwnode
151 * @hwirq: hardware IRQ number
152 * @triggering: triggering attributes of hwirq
153 * @polarity: polarity attributes of hwirq
154 * @polarity: polarity attributes of hwirq
155 * @shareable: shareable attributes of hwirq
156 * @wake_capable: wake capable attribute of hwirq
157 * @ctx: acpi_irq_parse_one_ctx updated by this function
158 *
159 * Description:
160 * Handle a matching IRQ resource by populating the given ctx with
161 * the information passed.
162 */
163static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode,
164 u32 hwirq, u8 triggering,
165 u8 polarity, u8 shareable,
166 u8 wake_capable,
167 struct acpi_irq_parse_one_ctx *ctx)
168{
169 if (!fwnode)
170 return;
171 ctx->rc = 0;
172 *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable, wake_capable);
173 ctx->fwspec->fwnode = fwnode;
174 ctx->fwspec->param[0] = hwirq;
175 ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity);
176 ctx->fwspec->param_count = 2;
177}
178
179/**
180 * acpi_irq_parse_one_cb - Handle the given resource.
181 * @ares: resource to handle
182 * @context: context for the walk
183 *
184 * Description:
185 * This is called by acpi_walk_resources passing each resource returned by
186 * the _CRS method. We only inspect IRQ resources. Since IRQ resources
187 * might contain multiple interrupts we check if the index is within this
188 * one's interrupt array, otherwise we subtract the current resource IRQ
189 * count from the lookup index to prepare for the next resource.
190 * Once a match is found we call acpi_irq_parse_one_match to populate
191 * the result and end the walk by returning AE_CTRL_TERMINATE.
192 *
193 * Return:
194 * AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching
195 * IRQ resource was found.
196 */
197static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,
198 void *context)
199{
200 struct acpi_irq_parse_one_ctx *ctx = context;
201 struct acpi_resource_irq *irq;
202 struct acpi_resource_extended_irq *eirq;
203 struct fwnode_handle *fwnode;
204
205 switch (ares->type) {
206 case ACPI_RESOURCE_TYPE_IRQ:
207 irq = &ares->data.irq;
208 if (ctx->index >= irq->interrupt_count) {
209 ctx->index -= irq->interrupt_count;
210 return AE_OK;
211 }
212 fwnode = acpi_get_gsi_domain_id(irq->interrupts[ctx->index]);
213 acpi_irq_parse_one_match(fwnode, hwirq: irq->interrupts[ctx->index],
214 triggering: irq->triggering, polarity: irq->polarity,
215 shareable: irq->shareable, wake_capable: irq->wake_capable, ctx);
216 return AE_CTRL_TERMINATE;
217 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
218 eirq = &ares->data.extended_irq;
219 if (eirq->producer_consumer == ACPI_PRODUCER)
220 return AE_OK;
221 if (ctx->index >= eirq->interrupt_count) {
222 ctx->index -= eirq->interrupt_count;
223 return AE_OK;
224 }
225 fwnode = acpi_get_irq_source_fwhandle(source: &eirq->resource_source,
226 gsi: eirq->interrupts[ctx->index]);
227 acpi_irq_parse_one_match(fwnode, hwirq: eirq->interrupts[ctx->index],
228 triggering: eirq->triggering, polarity: eirq->polarity,
229 shareable: eirq->shareable, wake_capable: eirq->wake_capable, ctx);
230 return AE_CTRL_TERMINATE;
231 }
232
233 return AE_OK;
234}
235
236/**
237 * acpi_irq_parse_one - Resolve an interrupt for a device
238 * @handle: the device whose interrupt is to be resolved
239 * @index: index of the interrupt to resolve
240 * @fwspec: structure irq_fwspec filled by this function
241 * @flags: resource flags filled by this function
242 *
243 * Description:
244 * Resolves an interrupt for a device by walking its CRS resources to find
245 * the appropriate ACPI IRQ resource and populating the given struct irq_fwspec
246 * and flags.
247 *
248 * Return:
249 * The result stored in ctx.rc by the callback, or the default -EINVAL value
250 * if an error occurs.
251 */
252static int acpi_irq_parse_one(acpi_handle handle, unsigned int index,
253 struct irq_fwspec *fwspec, unsigned long *flags)
254{
255 struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec };
256
257 acpi_walk_resources(device: handle, METHOD_NAME__CRS, user_function: acpi_irq_parse_one_cb, context: &ctx);
258 return ctx.rc;
259}
260
261/**
262 * acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource.
263 * @handle: ACPI device handle
264 * @index: ACPI IRQ resource index to lookup
265 * @res: Linux IRQ resource to initialize
266 *
267 * Description:
268 * Look for the ACPI IRQ resource with the given index and use it to initialize
269 * the given Linux IRQ resource.
270 *
271 * Return:
272 * 0 on success
273 * -EINVAL if an error occurs
274 * -EPROBE_DEFER if the IRQ lookup/conversion failed
275 */
276int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
277{
278 struct irq_fwspec fwspec;
279 struct irq_domain *domain;
280 unsigned long flags;
281 int rc;
282
283 rc = acpi_irq_parse_one(handle, index, fwspec: &fwspec, flags: &flags);
284 if (rc)
285 return rc;
286
287 domain = irq_find_matching_fwnode(fwnode: fwspec.fwnode, bus_token: DOMAIN_BUS_ANY);
288 if (!domain)
289 return -EPROBE_DEFER;
290
291 rc = irq_create_fwspec_mapping(fwspec: &fwspec);
292 if (rc <= 0)
293 return -EINVAL;
294
295 res->start = rc;
296 res->end = rc;
297 res->flags = flags;
298
299 return 0;
300}
301EXPORT_SYMBOL_GPL(acpi_irq_get);
302
303/**
304 * acpi_set_irq_model - Setup the GSI irqdomain information
305 * @model: the value assigned to acpi_irq_model
306 * @fn: a dispatcher function that will return the domain fwnode
307 * for a given GSI
308 */
309void __init acpi_set_irq_model(enum acpi_irq_model_id model,
310 struct fwnode_handle *(*fn)(u32))
311{
312 acpi_irq_model = model;
313 acpi_get_gsi_domain_id = fn;
314}
315
316/**
317 * acpi_set_gsi_to_irq_fallback - Register a GSI transfer
318 * callback to fallback to arch specified implementation.
319 * @fn: arch-specific fallback handler
320 */
321void __init acpi_set_gsi_to_irq_fallback(u32 (*fn)(u32))
322{
323 acpi_gsi_to_irq_fallback = fn;
324}
325
326/**
327 * acpi_irq_create_hierarchy - Create a hierarchical IRQ domain with the default
328 * GSI domain as its parent.
329 * @flags: Irq domain flags associated with the domain
330 * @size: Size of the domain.
331 * @fwnode: Optional fwnode of the interrupt controller
332 * @ops: Pointer to the interrupt domain callbacks
333 * @host_data: Controller private data pointer
334 */
335struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
336 unsigned int size,
337 struct fwnode_handle *fwnode,
338 const struct irq_domain_ops *ops,
339 void *host_data)
340{
341 struct irq_domain *d;
342
343 /* This only works for the GIC model... */
344 if (acpi_irq_model != ACPI_IRQ_MODEL_GIC)
345 return NULL;
346
347 d = irq_find_matching_fwnode(fwnode: acpi_get_gsi_domain_id(0),
348 bus_token: DOMAIN_BUS_ANY);
349
350 if (!d)
351 return NULL;
352
353 return irq_domain_create_hierarchy(parent: d, flags, size, fwnode, ops,
354 host_data);
355}
356EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy);
357

source code of linux/drivers/acpi/irq.c