linux/drivers/acpi/irq.c
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   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_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 */
  27int 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}
  39EXPORT_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 */
  51int 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}
  68EXPORT_SYMBOL_GPL(acpi_register_gsi);
  69
  70/**
  71 * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
  72 * @gsi: GSI IRQ number
  73 */
  74void 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 = irq_find_mapping(d, gsi);
  79
  80        irq_dispose_mapping(irq);
  81}
  82EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
  83
  84/**
  85 * acpi_get_irq_source_fwhandle() - Retrieve fwhandle from IRQ resource source.
  86 * @source: acpi_resource_source to use for the lookup.
  87 *
  88 * Description:
  89 * Retrieve the fwhandle of the device referenced by the given IRQ resource
  90 * source.
  91 *
  92 * Return:
  93 * The referenced device fwhandle or NULL on failure
  94 */
  95static struct fwnode_handle *
  96acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source)
  97{
  98        struct fwnode_handle *result;
  99        struct acpi_device *device;
 100        acpi_handle handle;
 101        acpi_status status;
 102
 103        if (!source->string_length)
 104                return acpi_gsi_domain_id;
 105
 106        status = acpi_get_handle(NULL, source->string_ptr, &handle);
 107        if (WARN_ON(ACPI_FAILURE(status)))
 108                return NULL;
 109
 110        device = acpi_bus_get_acpi_device(handle);
 111        if (WARN_ON(!device))
 112                return NULL;
 113
 114        result = &device->fwnode;
 115        acpi_bus_put_acpi_device(device);
 116        return result;
 117}
 118
 119/*
 120 * Context for the resource walk used to lookup IRQ resources.
 121 * Contains a return code, the lookup index, and references to the flags
 122 * and fwspec where the result is returned.
 123 */
 124struct acpi_irq_parse_one_ctx {
 125        int rc;
 126        unsigned int index;
 127        unsigned long *res_flags;
 128        struct irq_fwspec *fwspec;
 129};
 130
 131/**
 132 * acpi_irq_parse_one_match - Handle a matching IRQ resource.
 133 * @fwnode: matching fwnode
 134 * @hwirq: hardware IRQ number
 135 * @triggering: triggering attributes of hwirq
 136 * @polarity: polarity attributes of hwirq
 137 * @polarity: polarity attributes of hwirq
 138 * @shareable: shareable attributes of hwirq
 139 * @ctx: acpi_irq_parse_one_ctx updated by this function
 140 *
 141 * Description:
 142 * Handle a matching IRQ resource by populating the given ctx with
 143 * the information passed.
 144 */
 145static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode,
 146                                            u32 hwirq, u8 triggering,
 147                                            u8 polarity, u8 shareable,
 148                                            struct acpi_irq_parse_one_ctx *ctx)
 149{
 150        if (!fwnode)
 151                return;
 152        ctx->rc = 0;
 153        *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
 154        ctx->fwspec->fwnode = fwnode;
 155        ctx->fwspec->param[0] = hwirq;
 156        ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity);
 157        ctx->fwspec->param_count = 2;
 158}
 159
 160/**
 161 * acpi_irq_parse_one_cb - Handle the given resource.
 162 * @ares: resource to handle
 163 * @context: context for the walk
 164 *
 165 * Description:
 166 * This is called by acpi_walk_resources passing each resource returned by
 167 * the _CRS method. We only inspect IRQ resources. Since IRQ resources
 168 * might contain multiple interrupts we check if the index is within this
 169 * one's interrupt array, otherwise we subtract the current resource IRQ
 170 * count from the lookup index to prepare for the next resource.
 171 * Once a match is found we call acpi_irq_parse_one_match to populate
 172 * the result and end the walk by returning AE_CTRL_TERMINATE.
 173 *
 174 * Return:
 175 * AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching
 176 * IRQ resource was found.
 177 */
 178static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,
 179                                         void *context)
 180{
 181        struct acpi_irq_parse_one_ctx *ctx = context;
 182        struct acpi_resource_irq *irq;
 183        struct acpi_resource_extended_irq *eirq;
 184        struct fwnode_handle *fwnode;
 185
 186        switch (ares->type) {
 187        case ACPI_RESOURCE_TYPE_IRQ:
 188                irq = &ares->data.irq;
 189                if (ctx->index >= irq->interrupt_count) {
 190                        ctx->index -= irq->interrupt_count;
 191                        return AE_OK;
 192                }
 193                fwnode = acpi_gsi_domain_id;
 194                acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
 195                                         irq->triggering, irq->polarity,
 196                                         irq->shareable, ctx);
 197                return AE_CTRL_TERMINATE;
 198        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 199                eirq = &ares->data.extended_irq;
 200                if (eirq->producer_consumer == ACPI_PRODUCER)
 201                        return AE_OK;
 202                if (ctx->index >= eirq->interrupt_count) {
 203                        ctx->index -= eirq->interrupt_count;
 204                        return AE_OK;
 205                }
 206                fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source);
 207                acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
 208                                         eirq->triggering, eirq->polarity,
 209                                         eirq->shareable, ctx);
 210                return AE_CTRL_TERMINATE;
 211        }
 212
 213        return AE_OK;
 214}
 215
 216/**
 217 * acpi_irq_parse_one - Resolve an interrupt for a device
 218 * @handle: the device whose interrupt is to be resolved
 219 * @index: index of the interrupt to resolve
 220 * @fwspec: structure irq_fwspec filled by this function
 221 * @flags: resource flags filled by this function
 222 *
 223 * Description:
 224 * Resolves an interrupt for a device by walking its CRS resources to find
 225 * the appropriate ACPI IRQ resource and populating the given struct irq_fwspec
 226 * and flags.
 227 *
 228 * Return:
 229 * The result stored in ctx.rc by the callback, or the default -EINVAL value
 230 * if an error occurs.
 231 */
 232static int acpi_irq_parse_one(acpi_handle handle, unsigned int index,
 233                              struct irq_fwspec *fwspec, unsigned long *flags)
 234{
 235        struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec };
 236
 237        acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx);
 238        return ctx.rc;
 239}
 240
 241/**
 242 * acpi_irq_get - Lookup an ACPI IRQ resource and use it to initialize resource.
 243 * @handle: ACPI device handle
 244 * @index:  ACPI IRQ resource index to lookup
 245 * @res:    Linux IRQ resource to initialize
 246 *
 247 * Description:
 248 * Look for the ACPI IRQ resource with the given index and use it to initialize
 249 * the given Linux IRQ resource.
 250 *
 251 * Return:
 252 * 0 on success
 253 * -EINVAL if an error occurs
 254 * -EPROBE_DEFER if the IRQ lookup/conversion failed
 255 */
 256int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
 257{
 258        struct irq_fwspec fwspec;
 259        struct irq_domain *domain;
 260        unsigned long flags;
 261        int rc;
 262
 263        rc = acpi_irq_parse_one(handle, index, &fwspec, &flags);
 264        if (rc)
 265                return rc;
 266
 267        domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
 268        if (!domain)
 269                return -EPROBE_DEFER;
 270
 271        rc = irq_create_fwspec_mapping(&fwspec);
 272        if (rc <= 0)
 273                return -EINVAL;
 274
 275        res->start = rc;
 276        res->end = rc;
 277        res->flags = flags;
 278
 279        return 0;
 280}
 281EXPORT_SYMBOL_GPL(acpi_irq_get);
 282
 283/**
 284 * acpi_set_irq_model - Setup the GSI irqdomain information
 285 * @model: the value assigned to acpi_irq_model
 286 * @fwnode: the irq_domain identifier for mapping and looking up
 287 *          GSI interrupts
 288 */
 289void __init acpi_set_irq_model(enum acpi_irq_model_id model,
 290                               struct fwnode_handle *fwnode)
 291{
 292        acpi_irq_model = model;
 293        acpi_gsi_domain_id = fwnode;
 294}
 295
 296/**
 297 * acpi_irq_create_hierarchy - Create a hierarchical IRQ domain with the default
 298 *                             GSI domain as its parent.
 299 * @flags:      Irq domain flags associated with the domain
 300 * @size:       Size of the domain.
 301 * @fwnode:     Optional fwnode of the interrupt controller
 302 * @ops:        Pointer to the interrupt domain callbacks
 303 * @host_data:  Controller private data pointer
 304 */
 305struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
 306                                             unsigned int size,
 307                                             struct fwnode_handle *fwnode,
 308                                             const struct irq_domain_ops *ops,
 309                                             void *host_data)
 310{
 311        struct irq_domain *d = irq_find_matching_fwnode(acpi_gsi_domain_id,
 312                                                        DOMAIN_BUS_ANY);
 313
 314        if (!d)
 315                return NULL;
 316
 317        return irq_domain_create_hierarchy(d, flags, size, fwnode, ops,
 318                                           host_data);
 319}
 320EXPORT_SYMBOL_GPL(acpi_irq_create_hierarchy);
 321