drivers/acpi/irq.c

   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         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  */
  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 *
 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  */
 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  */
 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  */
 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  */
 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  */
 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  */
 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  */
 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);