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 * @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 */ 106 static struct fwnode_handle * 107 acpi_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 */ 136 struct 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 */ 158 static 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 */ 192 static 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 */ 247 static 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 */ 271 int 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 } 296 EXPORT_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 */ 304 void __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 */ 316 void __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 */ 330 struct 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 } 351 EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy); 352