kernel/irq/msi.c

   1 /*
   2  * linux/kernel/irq/msi.c
   3  *
   4  * Copyright (C) 2014 Intel Corp.
   5  * Author: Jiang Liu <jiang.liu@linux.intel.com>
   6  *
   7  * This file is licensed under GPLv2.
   8  *
   9  * This file contains common code to support Message Signalled Interrupt for
  10  * PCI compatible and non PCI compatible devices.
  11  */
  12 #include <linux/types.h>
  13 #include <linux/device.h>
  14 #include <linux/irq.h>
  15 #include <linux/irqdomain.h>
  16 #include <linux/msi.h>
  17 #include <linux/slab.h>
  18
  19 /**
  20  * alloc_msi_entry - Allocate an initialize msi_entry
  21  * @dev:        Pointer to the device for which this is allocated
  22  * @nvec:       The number of vectors used in this entry
  23  * @affinity:   Optional pointer to an affinity mask array size of @nvec
  24  *
  25  * If @affinity is not NULL then a an affinity array[@nvec] is allocated
  26  * and the affinity masks from @affinity are copied.
  27  */
  28 struct msi_desc *
  29 alloc_msi_entry(struct device *dev, int nvec, const struct cpumask *affinity)
  30 {
  31         struct msi_desc *desc;
  32
  33         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
  34         if (!desc)
  35                 return NULL;
  36
  37         INIT_LIST_HEAD(&desc->list);
  38         desc->dev = dev;
  39         desc->nvec_used = nvec;
  40         if (affinity) {
  41                 desc->affinity = kmemdup(affinity,
  42                         nvec * sizeof(*desc->affinity), GFP_KERNEL);
  43                 if (!desc->affinity) {
  44                         kfree(desc);
  45                         return NULL;
  46                 }
  47         }
  48
  49         return desc;
  50 }
  51
  52 void free_msi_entry(struct msi_desc *entry)
  53 {
  54         kfree(entry->affinity);
  55         kfree(entry);
  56 }
  57
  58 void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
  59 {
  60         *msg = entry->msg;
  61 }
  62
  63 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
  64 {
  65         struct msi_desc *entry = irq_get_msi_desc(irq);
  66
  67         __get_cached_msi_msg(entry, msg);
  68 }
  69 EXPORT_SYMBOL_GPL(get_cached_msi_msg);
  70
  71 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
  72 static inline void irq_chip_write_msi_msg(struct irq_data *data,
  73                                           struct msi_msg *msg)
  74 {
  75         data->chip->irq_write_msi_msg(data, msg);
  76 }
  77
  78 /**
  79  * msi_domain_set_affinity - Generic affinity setter function for MSI domains
  80  * @irq_data:   The irq data associated to the interrupt
  81  * @mask:       The affinity mask to set
  82  * @force:      Flag to enforce setting (disable online checks)
  83  *
  84  * Intended to be used by MSI interrupt controllers which are
  85  * implemented with hierarchical domains.
  86  */
  87 int msi_domain_set_affinity(struct irq_data *irq_data,
  88                             const struct cpumask *mask, bool force)
  89 {
  90         struct irq_data *parent = irq_data->parent_data;
  91         struct msi_msg msg;
  92         int ret;
  93
  94         ret = parent->chip->irq_set_affinity(parent, mask, force);
  95         if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
  96                 BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
  97                 irq_chip_write_msi_msg(irq_data, &msg);
  98         }
  99
 100         return ret;
 101 }
 102
 103 static void msi_domain_activate(struct irq_domain *domain,
 104                                 struct irq_data *irq_data)
 105 {
 106         struct msi_msg msg;
 107
 108         BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
 109         irq_chip_write_msi_msg(irq_data, &msg);
 110 }
 111
 112 static void msi_domain_deactivate(struct irq_domain *domain,
 113                                   struct irq_data *irq_data)
 114 {
 115         struct msi_msg msg;
 116
 117         memset(&msg, 0, sizeof(msg));
 118         irq_chip_write_msi_msg(irq_data, &msg);
 119 }
 120
 121 static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
 122                             unsigned int nr_irqs, void *arg)
 123 {
 124         struct msi_domain_info *info = domain->host_data;
 125         struct msi_domain_ops *ops = info->ops;
 126         irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
 127         int i, ret;
 128
 129         if (irq_find_mapping(domain, hwirq) > 0)
 130                 return -EEXIST;
 131
 132         if (domain->parent) {
 133                 ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
 134                 if (ret < 0)
 135                         return ret;
 136         }
 137
 138         for (i = 0; i < nr_irqs; i++) {
 139                 ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
 140                 if (ret < 0) {
 141                         if (ops->msi_free) {
 142                                 for (i--; i > 0; i--)
 143                                         ops->msi_free(domain, info, virq + i);
 144                         }
 145                         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 146                         return ret;
 147                 }
 148         }
 149
 150         return 0;
 151 }
 152
 153 static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
 154                             unsigned int nr_irqs)
 155 {
 156         struct msi_domain_info *info = domain->host_data;
 157         int i;
 158
 159         if (info->ops->msi_free) {
 160                 for (i = 0; i < nr_irqs; i++)
 161                         info->ops->msi_free(domain, info, virq + i);
 162         }
 163         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 164 }
 165
 166 static const struct irq_domain_ops msi_domain_ops = {
 167         .alloc          = msi_domain_alloc,
 168         .free           = msi_domain_free,
 169         .activate       = msi_domain_activate,
 170         .deactivate     = msi_domain_deactivate,
 171 };
 172
 173 #ifdef GENERIC_MSI_DOMAIN_OPS
 174 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
 175                                                 msi_alloc_info_t *arg)
 176 {
 177         return arg->hwirq;
 178 }
 179
 180 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
 181                                   int nvec, msi_alloc_info_t *arg)
 182 {
 183         memset(arg, 0, sizeof(*arg));
 184         return 0;
 185 }
 186
 187 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
 188                                     struct msi_desc *desc)
 189 {
 190         arg->desc = desc;
 191 }
 192 #else
 193 #define msi_domain_ops_get_hwirq        NULL
 194 #define msi_domain_ops_prepare          NULL
 195 #define msi_domain_ops_set_desc         NULL
 196 #endif /* !GENERIC_MSI_DOMAIN_OPS */
 197
 198 static int msi_domain_ops_init(struct irq_domain *domain,
 199                                struct msi_domain_info *info,
 200                                unsigned int virq, irq_hw_number_t hwirq,
 201                                msi_alloc_info_t *arg)
 202 {
 203         irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
 204                                       info->chip_data);
 205         if (info->handler && info->handler_name) {
 206                 __irq_set_handler(virq, info->handler, 0, info->handler_name);
 207                 if (info->handler_data)
 208                         irq_set_handler_data(virq, info->handler_data);
 209         }
 210         return 0;
 211 }
 212
 213 static int msi_domain_ops_check(struct irq_domain *domain,
 214                                 struct msi_domain_info *info,
 215                                 struct device *dev)
 216 {
 217         return 0;
 218 }
 219
 220 static struct msi_domain_ops msi_domain_ops_default = {
 221         .get_hwirq      = msi_domain_ops_get_hwirq,
 222         .msi_init       = msi_domain_ops_init,
 223         .msi_check      = msi_domain_ops_check,
 224         .msi_prepare    = msi_domain_ops_prepare,
 225         .set_desc       = msi_domain_ops_set_desc,
 226 };
 227
 228 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
 229 {
 230         struct msi_domain_ops *ops = info->ops;
 231
 232         if (ops == NULL) {
 233                 info->ops = &msi_domain_ops_default;
 234                 return;
 235         }
 236
 237         if (ops->get_hwirq == NULL)
 238                 ops->get_hwirq = msi_domain_ops_default.get_hwirq;
 239         if (ops->msi_init == NULL)
 240                 ops->msi_init = msi_domain_ops_default.msi_init;
 241         if (ops->msi_check == NULL)
 242                 ops->msi_check = msi_domain_ops_default.msi_check;
 243         if (ops->msi_prepare == NULL)
 244                 ops->msi_prepare = msi_domain_ops_default.msi_prepare;
 245         if (ops->set_desc == NULL)
 246                 ops->set_desc = msi_domain_ops_default.set_desc;
 247 }
 248
 249 static void msi_domain_update_chip_ops(struct msi_domain_info *info)
 250 {
 251         struct irq_chip *chip = info->chip;
 252
 253         BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask);
 254         if (!chip->irq_set_affinity)
 255                 chip->irq_set_affinity = msi_domain_set_affinity;
 256 }
 257
 258 /**
 259  * msi_create_irq_domain - Create a MSI interrupt domain
 260  * @fwnode:     Optional fwnode of the interrupt controller
 261  * @info:       MSI domain info
 262  * @parent:     Parent irq domain
 263  */
 264 struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
 265                                          struct msi_domain_info *info,
 266                                          struct irq_domain *parent)
 267 {
 268         if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
 269                 msi_domain_update_dom_ops(info);
 270         if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 271                 msi_domain_update_chip_ops(info);
 272
 273         return irq_domain_create_hierarchy(parent, IRQ_DOMAIN_FLAG_MSI, 0,
 274                                            fwnode, &msi_domain_ops, info);
 275 }
 276
 277 int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
 278                             int nvec, msi_alloc_info_t *arg)
 279 {
 280         struct msi_domain_info *info = domain->host_data;
 281         struct msi_domain_ops *ops = info->ops;
 282         int ret;
 283
 284         ret = ops->msi_check(domain, info, dev);
 285         if (ret == 0)
 286                 ret = ops->msi_prepare(domain, dev, nvec, arg);
 287
 288         return ret;
 289 }
 290
 291 int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 292                              int virq, int nvec, msi_alloc_info_t *arg)
 293 {
 294         struct msi_domain_info *info = domain->host_data;
 295         struct msi_domain_ops *ops = info->ops;
 296         struct msi_desc *desc;
 297         int ret = 0;
 298
 299         for_each_msi_entry(desc, dev) {
 300                 /* Don't even try the multi-MSI brain damage. */
 301                 if (WARN_ON(!desc->irq || desc->nvec_used != 1)) {
 302                         ret = -EINVAL;
 303                         break;
 304                 }
 305
 306                 if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
 307                         continue;
 308
 309                 ops->set_desc(arg, desc);
 310                 /* Assumes the domain mutex is held! */
 311                 ret = irq_domain_alloc_irqs_recursive(domain, virq, 1, arg);
 312                 if (ret)
 313                         break;
 314
 315                 irq_set_msi_desc_off(virq, 0, desc);
 316         }
 317
 318         if (ret) {
 319                 /* Mop up the damage */
 320                 for_each_msi_entry(desc, dev) {
 321                         if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
 322                                 continue;
 323
 324                         irq_domain_free_irqs_common(domain, desc->irq, 1);
 325                 }
 326         }
 327
 328         return ret;
 329 }
 330
 331 /**
 332  * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
 333  * @domain:     The domain to allocate from
 334  * @dev:        Pointer to device struct of the device for which the interrupts
 335  *              are allocated
 336  * @nvec:       The number of interrupts to allocate
 337  *
 338  * Returns 0 on success or an error code.
 339  */
 340 int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 341                           int nvec)
 342 {
 343         struct msi_domain_info *info = domain->host_data;
 344         struct msi_domain_ops *ops = info->ops;
 345         msi_alloc_info_t arg;
 346         struct msi_desc *desc;
 347         int i, ret, virq;
 348
 349         ret = msi_domain_prepare_irqs(domain, dev, nvec, &arg);
 350         if (ret)
 351                 return ret;
 352
 353         for_each_msi_entry(desc, dev) {
 354                 ops->set_desc(&arg, desc);
 355
 356                 virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
 357                                                dev_to_node(dev), &arg, false,
 358                                                desc->affinity);
 359                 if (virq < 0) {
 360                         ret = -ENOSPC;
 361                         if (ops->handle_error)
 362                                 ret = ops->handle_error(domain, desc, ret);
 363                         if (ops->msi_finish)
 364                                 ops->msi_finish(&arg, ret);
 365                         return ret;
 366                 }
 367
 368                 for (i = 0; i < desc->nvec_used; i++)
 369                         irq_set_msi_desc_off(virq, i, desc);
 370         }
 371
 372         if (ops->msi_finish)
 373                 ops->msi_finish(&arg, 0);
 374
 375         for_each_msi_entry(desc, dev) {
 376                 virq = desc->irq;
 377                 if (desc->nvec_used == 1)
 378                         dev_dbg(dev, "irq %d for MSI\n", virq);
 379                 else
 380                         dev_dbg(dev, "irq [%d-%d] for MSI\n",
 381                                 virq, virq + desc->nvec_used - 1);
 382                 /*
 383                  * This flag is set by the PCI layer as we need to activate
 384                  * the MSI entries before the PCI layer enables MSI in the
 385                  * card. Otherwise the card latches a random msi message.
 386                  */
 387                 if (info->flags & MSI_FLAG_ACTIVATE_EARLY) {
 388                         struct irq_data *irq_data;
 389
 390                         irq_data = irq_domain_get_irq_data(domain, desc->irq);
 391                         irq_domain_activate_irq(irq_data);
 392                 }
 393         }
 394
 395         return 0;
 396 }
 397
 398 /**
 399  * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
 400  * @domain:     The domain to managing the interrupts
 401  * @dev:        Pointer to device struct of the device for which the interrupts
 402  *              are free
 403  */
 404 void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
 405 {
 406         struct msi_desc *desc;
 407
 408         for_each_msi_entry(desc, dev) {
 409                 /*
 410                  * We might have failed to allocate an MSI early
 411                  * enough that there is no IRQ associated to this
 412                  * entry. If that's the case, don't do anything.
 413                  */
 414                 if (desc->irq) {
 415                         irq_domain_free_irqs(desc->irq, desc->nvec_used);
 416                         desc->irq = 0;
 417                 }
 418         }
 419 }
 420
 421 /**
 422  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
 423  * @domain:     The interrupt domain to retrieve data from
 424  *
 425  * Returns the pointer to the msi_domain_info stored in
 426  * @domain->host_data.
 427  */
 428 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
 429 {
 430         return (struct msi_domain_info *)domain->host_data;
 431 }
 432
 433 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */