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 void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
  22 {
  23         *msg = entry->msg;
  24 }
  25
  26 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
  27 {
  28         struct msi_desc *entry = irq_get_msi_desc(irq);
  29
  30         __get_cached_msi_msg(entry, msg);
  31 }
  32 EXPORT_SYMBOL_GPL(get_cached_msi_msg);
  33
  34 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
  35 static inline void irq_chip_write_msi_msg(struct irq_data *data,
  36                                           struct msi_msg *msg)
  37 {
  38         data->chip->irq_write_msi_msg(data, msg);
  39 }
  40
  41 /**
  42  * msi_domain_set_affinity - Generic affinity setter function for MSI domains
  43  * @irq_data:   The irq data associated to the interrupt
  44  * @mask:       The affinity mask to set
  45  * @force:      Flag to enforce setting (disable online checks)
  46  *
  47  * Intended to be used by MSI interrupt controllers which are
  48  * implemented with hierarchical domains.
  49  */
  50 int msi_domain_set_affinity(struct irq_data *irq_data,
  51                             const struct cpumask *mask, bool force)
  52 {
  53         struct irq_data *parent = irq_data->parent_data;
  54         struct msi_msg msg;
  55         int ret;
  56
  57         ret = parent->chip->irq_set_affinity(parent, mask, force);
  58         if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
  59                 BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
  60                 irq_chip_write_msi_msg(irq_data, &msg);
  61         }
  62
  63         return ret;
  64 }
  65
  66 static void msi_domain_activate(struct irq_domain *domain,
  67                                 struct irq_data *irq_data)
  68 {
  69         struct msi_msg msg;
  70
  71         BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
  72         irq_chip_write_msi_msg(irq_data, &msg);
  73 }
  74
  75 static void msi_domain_deactivate(struct irq_domain *domain,
  76                                   struct irq_data *irq_data)
  77 {
  78         struct msi_msg msg;
  79
  80         memset(&msg, 0, sizeof(msg));
  81         irq_chip_write_msi_msg(irq_data, &msg);
  82 }
  83
  84 static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
  85                             unsigned int nr_irqs, void *arg)
  86 {
  87         struct msi_domain_info *info = domain->host_data;
  88         struct msi_domain_ops *ops = info->ops;
  89         irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
  90         int i, ret;
  91
  92         if (irq_find_mapping(domain, hwirq) > 0)
  93                 return -EEXIST;
  94
  95         ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
  96         if (ret < 0)
  97                 return ret;
  98
  99         for (i = 0; i < nr_irqs; i++) {
 100                 ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
 101                 if (ret < 0) {
 102                         if (ops->msi_free) {
 103                                 for (i--; i > 0; i--)
 104                                         ops->msi_free(domain, info, virq + i);
 105                         }
 106                         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 107                         return ret;
 108                 }
 109         }
 110
 111         return 0;
 112 }
 113
 114 static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
 115                             unsigned int nr_irqs)
 116 {
 117         struct msi_domain_info *info = domain->host_data;
 118         int i;
 119
 120         if (info->ops->msi_free) {
 121                 for (i = 0; i < nr_irqs; i++)
 122                         info->ops->msi_free(domain, info, virq + i);
 123         }
 124         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 125 }
 126
 127 static struct irq_domain_ops msi_domain_ops = {
 128         .alloc          = msi_domain_alloc,
 129         .free           = msi_domain_free,
 130         .activate       = msi_domain_activate,
 131         .deactivate     = msi_domain_deactivate,
 132 };
 133
 134 #ifdef GENERIC_MSI_DOMAIN_OPS
 135 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
 136                                                 msi_alloc_info_t *arg)
 137 {
 138         return arg->hwirq;
 139 }
 140
 141 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
 142                                   int nvec, msi_alloc_info_t *arg)
 143 {
 144         memset(arg, 0, sizeof(*arg));
 145         return 0;
 146 }
 147
 148 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
 149                                     struct msi_desc *desc)
 150 {
 151         arg->desc = desc;
 152 }
 153 #else
 154 #define msi_domain_ops_get_hwirq        NULL
 155 #define msi_domain_ops_prepare          NULL
 156 #define msi_domain_ops_set_desc         NULL
 157 #endif /* !GENERIC_MSI_DOMAIN_OPS */
 158
 159 static int msi_domain_ops_init(struct irq_domain *domain,
 160                                struct msi_domain_info *info,
 161                                unsigned int virq, irq_hw_number_t hwirq,
 162                                msi_alloc_info_t *arg)
 163 {
 164         irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
 165                                       info->chip_data);
 166         if (info->handler && info->handler_name) {
 167                 __irq_set_handler(virq, info->handler, 0, info->handler_name);
 168                 if (info->handler_data)
 169                         irq_set_handler_data(virq, info->handler_data);
 170         }
 171         return 0;
 172 }
 173
 174 static int msi_domain_ops_check(struct irq_domain *domain,
 175                                 struct msi_domain_info *info,
 176                                 struct device *dev)
 177 {
 178         return 0;
 179 }
 180
 181 static struct msi_domain_ops msi_domain_ops_default = {
 182         .get_hwirq      = msi_domain_ops_get_hwirq,
 183         .msi_init       = msi_domain_ops_init,
 184         .msi_check      = msi_domain_ops_check,
 185         .msi_prepare    = msi_domain_ops_prepare,
 186         .set_desc       = msi_domain_ops_set_desc,
 187 };
 188
 189 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
 190 {
 191         struct msi_domain_ops *ops = info->ops;
 192
 193         if (ops == NULL) {
 194                 info->ops = &msi_domain_ops_default;
 195                 return;
 196         }
 197
 198         if (ops->get_hwirq == NULL)
 199                 ops->get_hwirq = msi_domain_ops_default.get_hwirq;
 200         if (ops->msi_init == NULL)
 201                 ops->msi_init = msi_domain_ops_default.msi_init;
 202         if (ops->msi_check == NULL)
 203                 ops->msi_check = msi_domain_ops_default.msi_check;
 204         if (ops->msi_prepare == NULL)
 205                 ops->msi_prepare = msi_domain_ops_default.msi_prepare;
 206         if (ops->set_desc == NULL)
 207                 ops->set_desc = msi_domain_ops_default.set_desc;
 208 }
 209
 210 static void msi_domain_update_chip_ops(struct msi_domain_info *info)
 211 {
 212         struct irq_chip *chip = info->chip;
 213
 214         BUG_ON(!chip);
 215         if (!chip->irq_mask)
 216                 chip->irq_mask = pci_msi_mask_irq;
 217         if (!chip->irq_unmask)
 218                 chip->irq_unmask = pci_msi_unmask_irq;
 219         if (!chip->irq_set_affinity)
 220                 chip->irq_set_affinity = msi_domain_set_affinity;
 221 }
 222
 223 /**
 224  * msi_create_irq_domain - Create a MSI interrupt domain
 225  * @of_node:    Optional device-tree node of the interrupt controller
 226  * @info:       MSI domain info
 227  * @parent:     Parent irq domain
 228  */
 229 struct irq_domain *msi_create_irq_domain(struct device_node *node,
 230                                          struct msi_domain_info *info,
 231                                          struct irq_domain *parent)
 232 {
 233         if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
 234                 msi_domain_update_dom_ops(info);
 235         if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 236                 msi_domain_update_chip_ops(info);
 237
 238         return irq_domain_add_hierarchy(parent, 0, 0, node, &msi_domain_ops,
 239                                         info);
 240 }
 241
 242 /**
 243  * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
 244  * @domain:     The domain to allocate from
 245  * @dev:        Pointer to device struct of the device for which the interrupts
 246  *              are allocated
 247  * @nvec:       The number of interrupts to allocate
 248  *
 249  * Returns 0 on success or an error code.
 250  */
 251 int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
 252                           int nvec)
 253 {
 254         struct msi_domain_info *info = domain->host_data;
 255         struct msi_domain_ops *ops = info->ops;
 256         msi_alloc_info_t arg;
 257         struct msi_desc *desc;
 258         int i, ret, virq = -1;
 259
 260         ret = ops->msi_check(domain, info, dev);
 261         if (ret == 0)
 262                 ret = ops->msi_prepare(domain, dev, nvec, &arg);
 263         if (ret)
 264                 return ret;
 265
 266         for_each_msi_entry(desc, dev) {
 267                 ops->set_desc(&arg, desc);
 268                 if (info->flags & MSI_FLAG_IDENTITY_MAP)
 269                         virq = (int)ops->get_hwirq(info, &arg);
 270                 else
 271                         virq = -1;
 272
 273                 virq = __irq_domain_alloc_irqs(domain, virq, desc->nvec_used,
 274                                                dev_to_node(dev), &arg, false);
 275                 if (virq < 0) {
 276                         ret = -ENOSPC;
 277                         if (ops->handle_error)
 278                                 ret = ops->handle_error(domain, desc, ret);
 279                         if (ops->msi_finish)
 280                                 ops->msi_finish(&arg, ret);
 281                         return ret;
 282                 }
 283
 284                 for (i = 0; i < desc->nvec_used; i++)
 285                         irq_set_msi_desc_off(virq, i, desc);
 286         }
 287
 288         if (ops->msi_finish)
 289                 ops->msi_finish(&arg, 0);
 290
 291         for_each_msi_entry(desc, dev) {
 292                 if (desc->nvec_used == 1)
 293                         dev_dbg(dev, "irq %d for MSI\n", virq);
 294                 else
 295                         dev_dbg(dev, "irq [%d-%d] for MSI\n",
 296                                 virq, virq + desc->nvec_used - 1);
 297         }
 298
 299         return 0;
 300 }
 301
 302 /**
 303  * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
 304  * @domain:     The domain to managing the interrupts
 305  * @dev:        Pointer to device struct of the device for which the interrupts
 306  *              are free
 307  */
 308 void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
 309 {
 310         struct msi_desc *desc;
 311
 312         for_each_msi_entry(desc, dev) {
 313                 irq_domain_free_irqs(desc->irq, desc->nvec_used);
 314                 desc->irq = 0;
 315         }
 316 }
 317
 318 /**
 319  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
 320  * @domain:     The interrupt domain to retrieve data from
 321  *
 322  * Returns the pointer to the msi_domain_info stored in
 323  * @domain->host_data.
 324  */
 325 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
 326 {
 327         return (struct msi_domain_info *)domain->host_data;
 328 }
 329
 330 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */