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 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} 78EXPORT_SYMBOL_GPL(acpi_register_gsi); 79 80/** 81 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping 82 * @gsi: GSI IRQ number 83 */ 84void 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} 97EXPORT_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 */ 111static struct fwnode_handle * 112acpi_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 */ 141struct 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 */ 163static 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 */ 197static 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 */ 252static 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 */ 276int 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} 301EXPORT_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 */ 309void __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 */ 321void __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 */ 335struct 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} 356EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy); 357