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