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
  18 /* Temparory solution for building, will be removed later */
  19 #include <linux/pci.h>
  20
  21 /**
  22  * alloc_msi_entry - Allocate an initialize msi_entry
  23  * @dev:        Pointer to the device for which this is allocated
  24  * @nvec:       The number of vectors used in this entry
  25  * @affinity:   Optional pointer to an affinity mask array size of @nvec
  26  *
  27  * If @affinity is not NULL then a an affinity array[@nvec] is allocated
  28  * and the affinity masks from @affinity are copied.
  29  */
  30 struct msi_desc *
  31 alloc_msi_entry(struct device *dev, int nvec, const struct cpumask *affinity)
  32 {
  33         struct msi_desc *desc;
  34
  35         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
  36         if (!desc)
  37                 return NULL;
  38
  39         INIT_LIST_HEAD(&desc->list);
  40         desc->dev = dev;
  41         desc->nvec_used = nvec;
  42         if (affinity) {
  43                 desc->affinity = kmemdup(affinity,
  44                         nvec * sizeof(*desc->affinity), GFP_KERNEL);
  45                 if (!desc->affinity) {
  46                         kfree(desc);
  47                         return NULL;
  48                 }
  49         }
  50
  51         return desc;
  52 }
  53
  54 void free_msi_entry(struct msi_desc *entry)
  55 {
  56         kfree(entry->affinity);
  57         kfree(entry);
  58 }
  59
  60 void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
  61 {
  62         *msg = entry->msg;
  63 }
  64
  65 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
  66 {
  67         struct msi_desc *entry = irq_get_msi_desc(irq);
  68
  69         __get_cached_msi_msg(entry, msg);
  70 }
  71 EXPORT_SYMBOL_GPL(get_cached_msi_msg);
  72
  73 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
  74 static inline void irq_chip_write_msi_msg(struct irq_data *data,
  75                                           struct msi_msg *msg)
  76 {
  77         data->chip->irq_write_msi_msg(data, msg);
  78 }
  79
  80 /**
  81  * msi_domain_set_affinity - Generic affinity setter function for MSI domains
  82  * @irq_data:   The irq data associated to the interrupt
  83  * @mask:       The affinity mask to set
  84  * @force:      Flag to enforce setting (disable online checks)
  85  *
  86  * Intended to be used by MSI interrupt controllers which are
  87  * implemented with hierarchical domains.
  88  */
  89 int msi_domain_set_affinity(struct irq_data *irq_data,
  90                             const struct cpumask *mask, bool force)
  91 {
  92         struct irq_data *parent = irq_data->parent_data;
  93         struct msi_msg msg;
  94         int ret;
  95
  96         ret = parent->chip->irq_set_affinity(parent, mask, force);
  97         if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
  98                 BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
  99                 irq_chip_write_msi_msg(irq_data, &msg);
 100         }
 101
 102         return ret;
 103 }
 104
 105 static void msi_domain_activate(struct irq_domain *domain,
 106                                 struct irq_data *irq_data)
 107 {
 108         struct msi_msg msg;
 109
 110         BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
 111         irq_chip_write_msi_msg(irq_data, &msg);
 112 }
 113
 114 static void msi_domain_deactivate(struct irq_domain *domain,
 115                                   struct irq_data *irq_data)
 116 {
 117         struct msi_msg msg;
 118
 119         memset(&msg, 0, sizeof(msg));
 120         irq_chip_write_msi_msg(irq_data, &msg);
 121 }
 122
 123 static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
 124                             unsigned int nr_irqs, void *arg)
 125 {
 126         struct msi_domain_info *info = domain->host_data;
 127         struct msi_domain_ops *ops = info->ops;
 128         irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
 129         int i, ret;
 130
 131         if (irq_find_mapping(domain, hwirq) > 0)
 132                 return -EEXIST;
 133
 134         if (domain->parent) {
 135                 ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
 136                 if (ret < 0)
 137                         return ret;
 138         }
 139
 140         for (i = 0; i < nr_irqs; i++) {
 141                 ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
 142                 if (ret < 0) {
 143                         if (ops->msi_free) {
 144                                 for (i--; i > 0; i--)
 145                                         ops->msi_free(domain, info, virq + i);
 146                         }
 147                         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 148                         return ret;
 149                 }
 150         }
 151
 152         return 0;
 153 }
 154
 155 static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
 156                             unsigned int nr_irqs)
 157 {
 158         struct msi_domain_info *info = domain->host_data;
 159         int i;
 160
 161         if (info->ops->msi_free) {
 162                 for (i = 0; i < nr_irqs; i++)
 163                         info->ops->msi_free(domain, info, virq + i);
 164         }
 165         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 166 }
 167
 168 static const struct irq_domain_ops msi_domain_ops = {
 169         .alloc          = msi_domain_alloc,
 170         .free           = msi_domain_free,
 171         .activate       = msi_domain_activate,
 172         .deactivate     = msi_domain_deactivate,
 173 };
 174
 175 #ifdef GENERIC_MSI_DOMAIN_OPS
 176 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
 177                                                 msi_alloc_info_t *arg)
 178 {
 179         return arg->hwirq;
 180 }
 181
 182 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
 183                                   int nvec, msi_alloc_info_t *arg)
 184 {
 185         memset(arg, 0, sizeof(*arg));
 186         return 0;
 187 }
 188
 189 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
 190                                     struct msi_desc *desc)
 191 {
 192         arg->desc = desc;
 193 }
 194 #else
 195 #define msi_domain_ops_get_hwirq        NULL
 196 #define msi_domain_ops_prepare          NULL
 197 #define msi_domain_ops_set_desc         NULL
 198 #endif /* !GENERIC_MSI_DOMAIN_OPS */
 199
 200 static int msi_domain_ops_init(struct irq_domain *domain,
 201                                struct msi_domain_info *info,
 202                                unsigned int virq, irq_hw_number_t hwirq,
 203                                msi_alloc_info_t *arg)
 204 {
 205         irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
 206                                       info->chip_data);
 207         if (info->handler && info->handler_name) {
 208                 __irq_set_handler(virq, info->handler, 0, info->handler_name);
 209                 if (info->handler_data)
 210                         irq_set_handler_data(virq, info->handler_data);
 211         }
 212         return 0;
 213 }
 214
 215 static int msi_domain_ops_check(struct irq_domain *domain,
 216                                 struct msi_domain_info *info,
 217                                 struct device *dev)
 218 {
 219         return 0;
 220 }
 221
 222 static struct msi_domain_ops msi_domain_ops_default = {
 223         .get_hwirq      = msi_domain_ops_get_hwirq,
 224         .msi_init       = msi_domain_ops_init,
 225         .msi_check      = msi_domain_ops_check,
 226         .msi_prepare    = msi_domain_ops_prepare,
 227         .set_desc       = msi_domain_ops_set_desc,
 228 };
 229
 230 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
 231 {
 232         struct msi_domain_ops *ops = info->ops;
 233
 234         if (ops == NULL) {
 235                 info->ops = &msi_domain_ops_default;
 236                 return;
 237         }
 238
 239         if (ops->get_hwirq == NULL)
 240                 ops->get_hwirq = msi_domain_ops_default.get_hwirq;
 241         if (ops->msi_init == NULL)
 242                 ops->msi_init = msi_domain_ops_default.msi_init;
 243         if (ops->msi_check == NULL)
 244                 ops->msi_check = msi_domain_ops_default.msi_check;
 245         if (ops->msi_prepare == NULL)
 246                 ops->msi_prepare = msi_domain_ops_default.msi_prepare;
 247         if (ops->set_desc == NULL)
 248                 ops->set_desc = msi_domain_ops_default.set_desc;
 249 }
 250
 251 static void msi_domain_update_chip_ops(struct msi_domain_info *info)
 252 {
 253         struct irq_chip *chip = info->chip;
 254
 255         BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask);
 256         if (!chip->irq_set_affinity)
 257                 chip->irq_set_affinity = msi_domain_set_affinity;
 258 }
 259
 260 /**
 261  * msi_create_irq_domain - Create a MSI interrupt domain
 262  * @fwnode:     Optional fwnode of the interrupt controller
 263  * @info:       MSI domain info
 264  * @parent:     Parent irq domain
 265  */
 266 struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
 267                                          struct msi_domain_info *info,
 268                                          struct irq_domain *parent)
 269 {
 270         if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
 271                 msi_domain_update_dom_ops(info);
 272         if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 273                 msi_domain_update_chip_ops(info);
 274
 275         return irq_domain_create_hierarchy(parent, 0, 0, fwnode,
 276                                            &msi_domain_ops, info);
 277 }
 278
 279 int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
 280                             int nvec, msi_alloc_info_t *arg)
 281 {
 282         struct msi_domain_info *info = domain->host_data;
 283         struct msi_domain_ops *ops = info->ops;
 284         int ret;
 285
 286         ret = ops->msi_check(domain, info, dev);
 287         if (ret == 0)
 288                 ret = ops->msi_prepare(domain, dev, nvec, arg);
 289
 290         return ret;
 291 }
 292
 293 int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
 294                              int virq, int nvec, msi_alloc_info_t *arg)
 295 {
 296         struct msi_domain_info *info = domain->host_data;
 297         struct msi_domain_ops *ops = info->ops;
 298         struct msi_desc *desc;
 299         int ret = 0;
 300
 301         for_each_msi_entry(desc, dev) {
 302                 /* Don't even try the multi-MSI brain damage. */
 303                 if (WARN_ON(!desc->irq || desc->nvec_used != 1)) {
 304                         ret = -EINVAL;
 305                         break;
 306                 }
 307
 308                 if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
 309                         continue;
 310
 311                 ops->set_desc(arg, desc);
 312                 /* Assumes the domain mutex is held! */
 313                 ret = irq_domain_alloc_irqs_recursive(domain, virq, 1, arg);
 314                 if (ret)
 315                         break;
 316
 317                 irq_set_msi_desc_off(virq, 0, desc);
 318         }
 319
 320         if (ret) {
 321                 /* Mop up the damage */
 322                 for_each_msi_entry(desc, dev) {
 323                         if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
 324                                 continue;
 325
 326                         irq_domain_free_irqs_common(domain, desc->irq, 1);
 327                 }
 328         }
 329
 330         return ret;
 331 }
 332
 333 /**
 334  * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
 335  * @domain:     The domain to allocate from
 336  * @dev:        Pointer to device struct of the device for which the interrupts
 337  *              are allocated
 338  * @nvec:       The number of interrupts to allocate
 339  *
 340  * Returns 0 on success or an error code.
 341  */
 342 int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 343                           int nvec)
 344 {
 345         struct msi_domain_info *info = domain->host_data;
 346         struct msi_domain_ops *ops = info->ops;
 347         msi_alloc_info_t arg;
 348         struct msi_desc *desc;
 349         int i, ret, virq;
 350
 351         ret = msi_domain_prepare_irqs(domain, dev, nvec, &arg);
 352         if (ret)
 353                 return ret;
 354
 355         for_each_msi_entry(desc, dev) {
 356                 ops->set_desc(&arg, desc);
 357
 358                 virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
 359                                                dev_to_node(dev), &arg, false,
 360                                                desc->affinity);
 361                 if (virq < 0) {
 362                         ret = -ENOSPC;
 363                         if (ops->handle_error)
 364                                 ret = ops->handle_error(domain, desc, ret);
 365                         if (ops->msi_finish)
 366                                 ops->msi_finish(&arg, ret);
 367                         return ret;
 368                 }
 369
 370                 for (i = 0; i < desc->nvec_used; i++)
 371                         irq_set_msi_desc_off(virq, i, desc);
 372         }
 373
 374         if (ops->msi_finish)
 375                 ops->msi_finish(&arg, 0);
 376
 377         for_each_msi_entry(desc, dev) {
 378                 virq = desc->irq;
 379                 if (desc->nvec_used == 1)
 380                         dev_dbg(dev, "irq %d for MSI\n", virq);
 381                 else
 382                         dev_dbg(dev, "irq [%d-%d] for MSI\n",
 383                                 virq, virq + desc->nvec_used - 1);
 384                 /*
 385                  * This flag is set by the PCI layer as we need to activate
 386                  * the MSI entries before the PCI layer enables MSI in the
 387                  * card. Otherwise the card latches a random msi message.
 388                  */
 389                 if (info->flags & MSI_FLAG_ACTIVATE_EARLY) {
 390                         struct irq_data *irq_data;
 391
 392                         irq_data = irq_domain_get_irq_data(domain, desc->irq);
 393                         irq_domain_activate_irq(irq_data);
 394                 }
 395         }
 396
 397         return 0;
 398 }
 399
 400 /**
 401  * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
 402  * @domain:     The domain to managing the interrupts
 403  * @dev:        Pointer to device struct of the device for which the interrupts
 404  *              are free
 405  */
 406 void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
 407 {
 408         struct msi_desc *desc;
 409
 410         for_each_msi_entry(desc, dev) {
 411                 /*
 412                  * We might have failed to allocate an MSI early
 413                  * enough that there is no IRQ associated to this
 414                  * entry. If that's the case, don't do anything.
 415                  */
 416                 if (desc->irq) {
 417                         irq_domain_free_irqs(desc->irq, desc->nvec_used);
 418                         desc->irq = 0;
 419                 }
 420         }
 421 }
 422
 423 /**
 424  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
 425  * @domain:     The interrupt domain to retrieve data from
 426  *
 427  * Returns the pointer to the msi_domain_info stored in
 428  * @domain->host_data.
 429  */
 430 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
 431 {
 432         return (struct msi_domain_info *)domain->host_data;
 433 }
 434
 435 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */