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_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 */ 27 int 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 } 39 EXPORT_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 */ 51 int 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 } 68 EXPORT_SYMBOL_GPL(acpi_register_gsi); 69 70 /** 71 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping 72 * @gsi: GSI IRQ number 73 */ 74 void 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 } 86 EXPORT_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 */ 99 static struct fwnode_handle * 100 acpi_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 */ 128 struct 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 */ 149 static 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 */ 182 static 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 */ 236 static 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 */ 260 int 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 } 285 EXPORT_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 */ 293 void __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 */ 309 struct 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 } 324 EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy); 325