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