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         ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
 113         if (ret < 0)
 114                 return ret;
 115
 116         for (i = 0; i < nr_irqs; i++) {
 117                 ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
 118                 if (ret < 0) {
 119                         if (ops->msi_free) {
 120                                 for (i--; i > 0; i--)
 121                                         ops->msi_free(domain, info, virq + i);
 122                         }
 123                         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 124                         return ret;
 125                 }
 126         }
 127
 128         return 0;
 129 }
 130
 131 static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
 132                             unsigned int nr_irqs)
 133 {
 134         struct msi_domain_info *info = domain->host_data;
 135         int i;
 136
 137         if (info->ops->msi_free) {
 138                 for (i = 0; i < nr_irqs; i++)
 139                         info->ops->msi_free(domain, info, virq + i);
 140         }
 141         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 142 }
 143
 144 static const struct irq_domain_ops msi_domain_ops = {
 145         .alloc          = msi_domain_alloc,
 146         .free           = msi_domain_free,
 147         .activate       = msi_domain_activate,
 148         .deactivate     = msi_domain_deactivate,
 149 };
 150
 151 #ifdef GENERIC_MSI_DOMAIN_OPS
 152 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
 153                                                 msi_alloc_info_t *arg)
 154 {
 155         return arg->hwirq;
 156 }
 157
 158 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
 159                                   int nvec, msi_alloc_info_t *arg)
 160 {
 161         memset(arg, 0, sizeof(*arg));
 162         return 0;
 163 }
 164
 165 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
 166                                     struct msi_desc *desc)
 167 {
 168         arg->desc = desc;
 169 }
 170 #else
 171 #define msi_domain_ops_get_hwirq        NULL
 172 #define msi_domain_ops_prepare          NULL
 173 #define msi_domain_ops_set_desc         NULL
 174 #endif /* !GENERIC_MSI_DOMAIN_OPS */
 175
 176 static int msi_domain_ops_init(struct irq_domain *domain,
 177                                struct msi_domain_info *info,
 178                                unsigned int virq, irq_hw_number_t hwirq,
 179                                msi_alloc_info_t *arg)
 180 {
 181         irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
 182                                       info->chip_data);
 183         if (info->handler && info->handler_name) {
 184                 __irq_set_handler(virq, info->handler, 0, info->handler_name);
 185                 if (info->handler_data)
 186                         irq_set_handler_data(virq, info->handler_data);
 187         }
 188         return 0;
 189 }
 190
 191 static int msi_domain_ops_check(struct irq_domain *domain,
 192                                 struct msi_domain_info *info,
 193                                 struct device *dev)
 194 {
 195         return 0;
 196 }
 197
 198 static struct msi_domain_ops msi_domain_ops_default = {
 199         .get_hwirq      = msi_domain_ops_get_hwirq,
 200         .msi_init       = msi_domain_ops_init,
 201         .msi_check      = msi_domain_ops_check,
 202         .msi_prepare    = msi_domain_ops_prepare,
 203         .set_desc       = msi_domain_ops_set_desc,
 204 };
 205
 206 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
 207 {
 208         struct msi_domain_ops *ops = info->ops;
 209
 210         if (ops == NULL) {
 211                 info->ops = &msi_domain_ops_default;
 212                 return;
 213         }
 214
 215         if (ops->get_hwirq == NULL)
 216                 ops->get_hwirq = msi_domain_ops_default.get_hwirq;
 217         if (ops->msi_init == NULL)
 218                 ops->msi_init = msi_domain_ops_default.msi_init;
 219         if (ops->msi_check == NULL)
 220                 ops->msi_check = msi_domain_ops_default.msi_check;
 221         if (ops->msi_prepare == NULL)
 222                 ops->msi_prepare = msi_domain_ops_default.msi_prepare;
 223         if (ops->set_desc == NULL)
 224                 ops->set_desc = msi_domain_ops_default.set_desc;
 225 }
 226
 227 static void msi_domain_update_chip_ops(struct msi_domain_info *info)
 228 {
 229         struct irq_chip *chip = info->chip;
 230
 231         BUG_ON(!chip);
 232         if (!chip->irq_mask)
 233                 chip->irq_mask = pci_msi_mask_irq;
 234         if (!chip->irq_unmask)
 235                 chip->irq_unmask = pci_msi_unmask_irq;
 236         if (!chip->irq_set_affinity)
 237                 chip->irq_set_affinity = msi_domain_set_affinity;
 238 }
 239
 240 /**
 241  * msi_create_irq_domain - Create a MSI interrupt domain
 242  * @of_node:    Optional device-tree node of the interrupt controller
 243  * @info:       MSI domain info
 244  * @parent:     Parent irq domain
 245  */
 246 struct irq_domain *msi_create_irq_domain(struct device_node *node,
 247                                          struct msi_domain_info *info,
 248                                          struct irq_domain *parent)
 249 {
 250         if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
 251                 msi_domain_update_dom_ops(info);
 252         if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 253                 msi_domain_update_chip_ops(info);
 254
 255         return irq_domain_add_hierarchy(parent, 0, 0, node, &msi_domain_ops,
 256                                         info);
 257 }
 258
 259 /**
 260  * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
 261  * @domain:     The domain to allocate from
 262  * @dev:        Pointer to device struct of the device for which the interrupts
 263  *              are allocated
 264  * @nvec:       The number of interrupts to allocate
 265  *
 266  * Returns 0 on success or an error code.
 267  */
 268 int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 269                           int nvec)
 270 {
 271         struct msi_domain_info *info = domain->host_data;
 272         struct msi_domain_ops *ops = info->ops;
 273         msi_alloc_info_t arg;
 274         struct msi_desc *desc;
 275         int i, ret, virq = -1;
 276
 277         ret = ops->msi_check(domain, info, dev);
 278         if (ret == 0)
 279                 ret = ops->msi_prepare(domain, dev, nvec, &arg);
 280         if (ret)
 281                 return ret;
 282
 283         for_each_msi_entry(desc, dev) {
 284                 ops->set_desc(&arg, desc);
 285                 if (info->flags & MSI_FLAG_IDENTITY_MAP)
 286                         virq = (int)ops->get_hwirq(info, &arg);
 287                 else
 288                         virq = -1;
 289
 290                 virq = __irq_domain_alloc_irqs(domain, virq, desc->nvec_used,
 291                                                dev_to_node(dev), &arg, false);
 292                 if (virq < 0) {
 293                         ret = -ENOSPC;
 294                         if (ops->handle_error)
 295                                 ret = ops->handle_error(domain, desc, ret);
 296                         if (ops->msi_finish)
 297                                 ops->msi_finish(&arg, ret);
 298                         return ret;
 299                 }
 300
 301                 for (i = 0; i < desc->nvec_used; i++)
 302                         irq_set_msi_desc_off(virq, i, desc);
 303         }
 304
 305         if (ops->msi_finish)
 306                 ops->msi_finish(&arg, 0);
 307
 308         for_each_msi_entry(desc, dev) {
 309                 if (desc->nvec_used == 1)
 310                         dev_dbg(dev, "irq %d for MSI\n", virq);
 311                 else
 312                         dev_dbg(dev, "irq [%d-%d] for MSI\n",
 313                                 virq, virq + desc->nvec_used - 1);
 314         }
 315
 316         return 0;
 317 }
 318
 319 /**
 320  * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
 321  * @domain:     The domain to managing the interrupts
 322  * @dev:        Pointer to device struct of the device for which the interrupts
 323  *              are free
 324  */
 325 void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
 326 {
 327         struct msi_desc *desc;
 328
 329         for_each_msi_entry(desc, dev) {
 330                 /*
 331                  * We might have failed to allocate an MSI early
 332                  * enough that there is no IRQ associated to this
 333                  * entry. If that's the case, don't do anything.
 334                  */
 335                 if (desc->irq) {
 336                         irq_domain_free_irqs(desc->irq, desc->nvec_used);
 337                         desc->irq = 0;
 338                 }
 339         }
 340 }
 341
 342 /**
 343  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
 344  * @domain:     The interrupt domain to retrieve data from
 345  *
 346  * Returns the pointer to the msi_domain_info stored in
 347  * @domain->host_data.
 348  */
 349 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
 350 {
 351         return (struct msi_domain_info *)domain->host_data;
 352 }
 353
 354 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */