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 
13 enum acpi_irq_model_id acpi_irq_model;
14 
15 static struct fwnode_handle *(*acpi_get_gsi_domain_id)(u32 gsi);
16 static 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  */
acpi_gsi_to_irq(u32 gsi,unsigned int * irq)28 int 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 }
44 EXPORT_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  */
acpi_register_gsi(struct device * dev,u32 gsi,int trigger,int polarity)56 int 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(trigger, polarity);
70 	fwspec.param_count = 2;
71 
72 	irq = irq_create_fwspec_mapping(&fwspec);
73 	if (!irq)
74 		return -EINVAL;
75 
76 	return irq;
77 }
78 EXPORT_SYMBOL_GPL(acpi_register_gsi);
79 
80 /**
81  * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
82  * @gsi: GSI IRQ number
83  */
acpi_unregister_gsi(u32 gsi)84 void 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(acpi_get_gsi_domain_id(gsi),
93 				     DOMAIN_BUS_ANY);
94 	irq = irq_find_mapping(d, gsi);
95 	irq_dispose_mapping(irq);
96 }
97 EXPORT_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  */
111 static struct fwnode_handle *
acpi_get_irq_source_fwhandle(const struct acpi_resource_source * source,u32 gsi)112 acpi_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, source->string_ptr, &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(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  */
141 struct 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  */
acpi_irq_parse_one_match(struct fwnode_handle * fwnode,u32 hwirq,u8 triggering,u8 polarity,u8 shareable,u8 wake_capable,struct acpi_irq_parse_one_ctx * ctx)163 static 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  */
acpi_irq_parse_one_cb(struct acpi_resource * ares,void * context)197 static 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, irq->interrupts[ctx->index],
214 					 irq->triggering, irq->polarity,
215 					 irq->shareable, 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(&eirq->resource_source,
226 						      eirq->interrupts[ctx->index]);
227 		acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
228 					 eirq->triggering, eirq->polarity,
229 					 eirq->shareable, 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  */
acpi_irq_parse_one(acpi_handle handle,unsigned int index,struct irq_fwspec * fwspec,unsigned long * flags)252 static 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(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &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  */
acpi_irq_get(acpi_handle handle,unsigned int index,struct resource * res)276 int 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, &flags);
284 	if (rc)
285 		return rc;
286 
287 	domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
288 	if (!domain)
289 		return -EPROBE_DEFER;
290 
291 	rc = irq_create_fwspec_mapping(&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 }
301 EXPORT_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  */
acpi_set_irq_model(enum acpi_irq_model_id model,struct fwnode_handle * (* fn)(u32))309 void __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  */
acpi_set_gsi_to_irq_fallback(u32 (* fn)(u32))321 void __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  */
acpi_irq_create_hierarchy(unsigned int flags,unsigned int size,struct fwnode_handle * fwnode,const struct irq_domain_ops * ops,void * host_data)335 struct 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(acpi_get_gsi_domain_id(0),
348 				     DOMAIN_BUS_ANY);
349 
350 	if (!d)
351 		return NULL;
352 
353 	return irq_domain_create_hierarchy(d, flags, size, fwnode, ops,
354 					   host_data);
355 }
356 EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy);
357