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 */ 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 */ 56 int 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 } 73 EXPORT_SYMBOL_GPL(acpi_register_gsi); 74 75 /** 76 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping 77 * @gsi: GSI IRQ number 78 */ 79 void 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 } 92 EXPORT_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 * 98 * Description: 99 * Retrieve the fwhandle of the device referenced by the given IRQ resource 100 * source. 101 * 102 * Return: 103 * The referenced device fwhandle or NULL on failure 104 */ 105 static struct fwnode_handle * 106 acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source, 107 u32 gsi) 108 { 109 struct fwnode_handle *result; 110 struct acpi_device *device; 111 acpi_handle handle; 112 acpi_status status; 113 114 if (!source->string_length) 115 return acpi_get_gsi_domain_id(gsi); 116 117 status = acpi_get_handle(NULL, source->string_ptr, &handle); 118 if (WARN_ON(ACPI_FAILURE(status))) 119 return NULL; 120 121 device = acpi_bus_get_acpi_device(handle); 122 if (WARN_ON(!device)) 123 return NULL; 124 125 result = &device->fwnode; 126 acpi_bus_put_acpi_device(device); 127 return result; 128 } 129 130 /* 131 * Context for the resource walk used to lookup IRQ resources. 132 * Contains a return code, the lookup index, and references to the flags 133 * and fwspec where the result is returned. 134 */ 135 struct acpi_irq_parse_one_ctx { 136 int rc; 137 unsigned int index; 138 unsigned long *res_flags; 139 struct irq_fwspec *fwspec; 140 }; 141 142 /** 143 * acpi_irq_parse_one_match - Handle a matching IRQ resource. 144 * @fwnode: matching fwnode 145 * @hwirq: hardware IRQ number 146 * @triggering: triggering attributes of hwirq 147 * @polarity: polarity attributes of hwirq 148 * @polarity: polarity attributes of hwirq 149 * @shareable: shareable attributes of hwirq 150 * @ctx: acpi_irq_parse_one_ctx updated by this function 151 * 152 * Description: 153 * Handle a matching IRQ resource by populating the given ctx with 154 * the information passed. 155 */ 156 static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode, 157 u32 hwirq, u8 triggering, 158 u8 polarity, u8 shareable, 159 struct acpi_irq_parse_one_ctx *ctx) 160 { 161 if (!fwnode) 162 return; 163 ctx->rc = 0; 164 *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable); 165 ctx->fwspec->fwnode = fwnode; 166 ctx->fwspec->param[0] = hwirq; 167 ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity); 168 ctx->fwspec->param_count = 2; 169 } 170 171 /** 172 * acpi_irq_parse_one_cb - Handle the given resource. 173 * @ares: resource to handle 174 * @context: context for the walk 175 * 176 * Description: 177 * This is called by acpi_walk_resources passing each resource returned by 178 * the _CRS method. We only inspect IRQ resources. Since IRQ resources 179 * might contain multiple interrupts we check if the index is within this 180 * one's interrupt array, otherwise we subtract the current resource IRQ 181 * count from the lookup index to prepare for the next resource. 182 * Once a match is found we call acpi_irq_parse_one_match to populate 183 * the result and end the walk by returning AE_CTRL_TERMINATE. 184 * 185 * Return: 186 * AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching 187 * IRQ resource was found. 188 */ 189 static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares, 190 void *context) 191 { 192 struct acpi_irq_parse_one_ctx *ctx = context; 193 struct acpi_resource_irq *irq; 194 struct acpi_resource_extended_irq *eirq; 195 struct fwnode_handle *fwnode; 196 197 switch (ares->type) { 198 case ACPI_RESOURCE_TYPE_IRQ: 199 irq = &ares->data.irq; 200 if (ctx->index >= irq->interrupt_count) { 201 ctx->index -= irq->interrupt_count; 202 return AE_OK; 203 } 204 fwnode = acpi_get_gsi_domain_id(irq->interrupts[ctx->index]); 205 acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index], 206 irq->triggering, irq->polarity, 207 irq->shareable, ctx); 208 return AE_CTRL_TERMINATE; 209 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: 210 eirq = &ares->data.extended_irq; 211 if (eirq->producer_consumer == ACPI_PRODUCER) 212 return AE_OK; 213 if (ctx->index >= eirq->interrupt_count) { 214 ctx->index -= eirq->interrupt_count; 215 return AE_OK; 216 } 217 fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source, 218 eirq->interrupts[ctx->index]); 219 acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index], 220 eirq->triggering, eirq->polarity, 221 eirq->shareable, ctx); 222 return AE_CTRL_TERMINATE; 223 } 224 225 return AE_OK; 226 } 227 228 /** 229 * acpi_irq_parse_one - Resolve an interrupt for a device 230 * @handle: the device whose interrupt is to be resolved 231 * @index: index of the interrupt to resolve 232 * @fwspec: structure irq_fwspec filled by this function 233 * @flags: resource flags filled by this function 234 * 235 * Description: 236 * Resolves an interrupt for a device by walking its CRS resources to find 237 * the appropriate ACPI IRQ resource and populating the given struct irq_fwspec 238 * and flags. 239 * 240 * Return: 241 * The result stored in ctx.rc by the callback, or the default -EINVAL value 242 * if an error occurs. 243 */ 244 static int acpi_irq_parse_one(acpi_handle handle, unsigned int index, 245 struct irq_fwspec *fwspec, unsigned long *flags) 246 { 247 struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec }; 248 249 acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx); 250 return ctx.rc; 251 } 252 253 /** 254 * acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource. 255 * @handle: ACPI device handle 256 * @index: ACPI IRQ resource index to lookup 257 * @res: Linux IRQ resource to initialize 258 * 259 * Description: 260 * Look for the ACPI IRQ resource with the given index and use it to initialize 261 * the given Linux IRQ resource. 262 * 263 * Return: 264 * 0 on success 265 * -EINVAL if an error occurs 266 * -EPROBE_DEFER if the IRQ lookup/conversion failed 267 */ 268 int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res) 269 { 270 struct irq_fwspec fwspec; 271 struct irq_domain *domain; 272 unsigned long flags; 273 int rc; 274 275 rc = acpi_irq_parse_one(handle, index, &fwspec, &flags); 276 if (rc) 277 return rc; 278 279 domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY); 280 if (!domain) 281 return -EPROBE_DEFER; 282 283 rc = irq_create_fwspec_mapping(&fwspec); 284 if (rc <= 0) 285 return -EINVAL; 286 287 res->start = rc; 288 res->end = rc; 289 res->flags = flags; 290 291 return 0; 292 } 293 EXPORT_SYMBOL_GPL(acpi_irq_get); 294 295 /** 296 * acpi_set_irq_model - Setup the GSI irqdomain information 297 * @model: the value assigned to acpi_irq_model 298 * @fwnode: the irq_domain identifier for mapping and looking up 299 * GSI interrupts 300 */ 301 void __init acpi_set_irq_model(enum acpi_irq_model_id model, 302 struct fwnode_handle *(*fn)(u32)) 303 { 304 acpi_irq_model = model; 305 acpi_get_gsi_domain_id = fn; 306 } 307 308 /** 309 * acpi_set_gsi_to_irq_fallback - Register a GSI transfer 310 * callback to fallback to arch specified implementation. 311 * @fn: arch-specific fallback handler 312 */ 313 void __init acpi_set_gsi_to_irq_fallback(u32 (*fn)(u32)) 314 { 315 acpi_gsi_to_irq_fallback = fn; 316 } 317 318 /** 319 * acpi_irq_create_hierarchy - Create a hierarchical IRQ domain with the default 320 * GSI domain as its parent. 321 * @flags: Irq domain flags associated with the domain 322 * @size: Size of the domain. 323 * @fwnode: Optional fwnode of the interrupt controller 324 * @ops: Pointer to the interrupt domain callbacks 325 * @host_data: Controller private data pointer 326 */ 327 struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags, 328 unsigned int size, 329 struct fwnode_handle *fwnode, 330 const struct irq_domain_ops *ops, 331 void *host_data) 332 { 333 struct irq_domain *d; 334 335 /* This only works for the GIC model... */ 336 if (acpi_irq_model != ACPI_IRQ_MODEL_GIC) 337 return NULL; 338 339 d = irq_find_matching_fwnode(acpi_get_gsi_domain_id(0), 340 DOMAIN_BUS_ANY); 341 342 if (!d) 343 return NULL; 344 345 return irq_domain_create_hierarchy(d, flags, size, fwnode, ops, 346 host_data); 347 } 348 EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy); 349