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