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0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2014 Intel Corp.
0004  * Author: Jiang Liu <jiang.liu@linux.intel.com>
0005  *
0006  * This file is licensed under GPLv2.
0007  *
0008  * This file contains common code to support Message Signaled Interrupts for
0009  * PCI compatible and non PCI compatible devices.
0010  */
0011 #include <linux/types.h>
0012 #include <linux/device.h>
0013 #include <linux/irq.h>
0014 #include <linux/irqdomain.h>
0015 #include <linux/msi.h>
0016 #include <linux/slab.h>
0017 #include <linux/sysfs.h>
0018 #include <linux/pci.h>
0019 
0020 #include "internals.h"
0021 
0022 static inline int msi_sysfs_create_group(struct device *dev);
0023 
0024 /**
0025  * msi_alloc_desc - Allocate an initialized msi_desc
0026  * @dev:    Pointer to the device for which this is allocated
0027  * @nvec:   The number of vectors used in this entry
0028  * @affinity:   Optional pointer to an affinity mask array size of @nvec
0029  *
0030  * If @affinity is not %NULL then an affinity array[@nvec] is allocated
0031  * and the affinity masks and flags from @affinity are copied.
0032  *
0033  * Return: pointer to allocated &msi_desc on success or %NULL on failure
0034  */
0035 static struct msi_desc *msi_alloc_desc(struct device *dev, int nvec,
0036                     const struct irq_affinity_desc *affinity)
0037 {
0038     struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
0039 
0040     if (!desc)
0041         return NULL;
0042 
0043     desc->dev = dev;
0044     desc->nvec_used = nvec;
0045     if (affinity) {
0046         desc->affinity = kmemdup(affinity, nvec * sizeof(*desc->affinity), GFP_KERNEL);
0047         if (!desc->affinity) {
0048             kfree(desc);
0049             return NULL;
0050         }
0051     }
0052     return desc;
0053 }
0054 
0055 static void msi_free_desc(struct msi_desc *desc)
0056 {
0057     kfree(desc->affinity);
0058     kfree(desc);
0059 }
0060 
0061 static int msi_insert_desc(struct msi_device_data *md, struct msi_desc *desc, unsigned int index)
0062 {
0063     int ret;
0064 
0065     desc->msi_index = index;
0066     ret = xa_insert(&md->__store, index, desc, GFP_KERNEL);
0067     if (ret)
0068         msi_free_desc(desc);
0069     return ret;
0070 }
0071 
0072 /**
0073  * msi_add_msi_desc - Allocate and initialize a MSI descriptor
0074  * @dev:    Pointer to the device for which the descriptor is allocated
0075  * @init_desc:  Pointer to an MSI descriptor to initialize the new descriptor
0076  *
0077  * Return: 0 on success or an appropriate failure code.
0078  */
0079 int msi_add_msi_desc(struct device *dev, struct msi_desc *init_desc)
0080 {
0081     struct msi_desc *desc;
0082 
0083     lockdep_assert_held(&dev->msi.data->mutex);
0084 
0085     desc = msi_alloc_desc(dev, init_desc->nvec_used, init_desc->affinity);
0086     if (!desc)
0087         return -ENOMEM;
0088 
0089     /* Copy type specific data to the new descriptor. */
0090     desc->pci = init_desc->pci;
0091     return msi_insert_desc(dev->msi.data, desc, init_desc->msi_index);
0092 }
0093 
0094 /**
0095  * msi_add_simple_msi_descs - Allocate and initialize MSI descriptors
0096  * @dev:    Pointer to the device for which the descriptors are allocated
0097  * @index:  Index for the first MSI descriptor
0098  * @ndesc:  Number of descriptors to allocate
0099  *
0100  * Return: 0 on success or an appropriate failure code.
0101  */
0102 static int msi_add_simple_msi_descs(struct device *dev, unsigned int index, unsigned int ndesc)
0103 {
0104     unsigned int idx, last = index + ndesc - 1;
0105     struct msi_desc *desc;
0106     int ret;
0107 
0108     lockdep_assert_held(&dev->msi.data->mutex);
0109 
0110     for (idx = index; idx <= last; idx++) {
0111         desc = msi_alloc_desc(dev, 1, NULL);
0112         if (!desc)
0113             goto fail_mem;
0114         ret = msi_insert_desc(dev->msi.data, desc, idx);
0115         if (ret)
0116             goto fail;
0117     }
0118     return 0;
0119 
0120 fail_mem:
0121     ret = -ENOMEM;
0122 fail:
0123     msi_free_msi_descs_range(dev, MSI_DESC_NOTASSOCIATED, index, last);
0124     return ret;
0125 }
0126 
0127 static bool msi_desc_match(struct msi_desc *desc, enum msi_desc_filter filter)
0128 {
0129     switch (filter) {
0130     case MSI_DESC_ALL:
0131         return true;
0132     case MSI_DESC_NOTASSOCIATED:
0133         return !desc->irq;
0134     case MSI_DESC_ASSOCIATED:
0135         return !!desc->irq;
0136     }
0137     WARN_ON_ONCE(1);
0138     return false;
0139 }
0140 
0141 /**
0142  * msi_free_msi_descs_range - Free MSI descriptors of a device
0143  * @dev:        Device to free the descriptors
0144  * @filter:     Descriptor state filter
0145  * @first_index:    Index to start freeing from
0146  * @last_index:     Last index to be freed
0147  */
0148 void msi_free_msi_descs_range(struct device *dev, enum msi_desc_filter filter,
0149                   unsigned int first_index, unsigned int last_index)
0150 {
0151     struct xarray *xa = &dev->msi.data->__store;
0152     struct msi_desc *desc;
0153     unsigned long idx;
0154 
0155     lockdep_assert_held(&dev->msi.data->mutex);
0156 
0157     xa_for_each_range(xa, idx, desc, first_index, last_index) {
0158         if (msi_desc_match(desc, filter)) {
0159             xa_erase(xa, idx);
0160             msi_free_desc(desc);
0161         }
0162     }
0163 }
0164 
0165 void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
0166 {
0167     *msg = entry->msg;
0168 }
0169 
0170 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
0171 {
0172     struct msi_desc *entry = irq_get_msi_desc(irq);
0173 
0174     __get_cached_msi_msg(entry, msg);
0175 }
0176 EXPORT_SYMBOL_GPL(get_cached_msi_msg);
0177 
0178 static void msi_device_data_release(struct device *dev, void *res)
0179 {
0180     struct msi_device_data *md = res;
0181 
0182     WARN_ON_ONCE(!xa_empty(&md->__store));
0183     xa_destroy(&md->__store);
0184     dev->msi.data = NULL;
0185 }
0186 
0187 /**
0188  * msi_setup_device_data - Setup MSI device data
0189  * @dev:    Device for which MSI device data should be set up
0190  *
0191  * Return: 0 on success, appropriate error code otherwise
0192  *
0193  * This can be called more than once for @dev. If the MSI device data is
0194  * already allocated the call succeeds. The allocated memory is
0195  * automatically released when the device is destroyed.
0196  */
0197 int msi_setup_device_data(struct device *dev)
0198 {
0199     struct msi_device_data *md;
0200     int ret;
0201 
0202     if (dev->msi.data)
0203         return 0;
0204 
0205     md = devres_alloc(msi_device_data_release, sizeof(*md), GFP_KERNEL);
0206     if (!md)
0207         return -ENOMEM;
0208 
0209     ret = msi_sysfs_create_group(dev);
0210     if (ret) {
0211         devres_free(md);
0212         return ret;
0213     }
0214 
0215     xa_init(&md->__store);
0216     mutex_init(&md->mutex);
0217     dev->msi.data = md;
0218     devres_add(dev, md);
0219     return 0;
0220 }
0221 
0222 /**
0223  * msi_lock_descs - Lock the MSI descriptor storage of a device
0224  * @dev:    Device to operate on
0225  */
0226 void msi_lock_descs(struct device *dev)
0227 {
0228     mutex_lock(&dev->msi.data->mutex);
0229 }
0230 EXPORT_SYMBOL_GPL(msi_lock_descs);
0231 
0232 /**
0233  * msi_unlock_descs - Unlock the MSI descriptor storage of a device
0234  * @dev:    Device to operate on
0235  */
0236 void msi_unlock_descs(struct device *dev)
0237 {
0238     /* Invalidate the index wich was cached by the iterator */
0239     dev->msi.data->__iter_idx = MSI_MAX_INDEX;
0240     mutex_unlock(&dev->msi.data->mutex);
0241 }
0242 EXPORT_SYMBOL_GPL(msi_unlock_descs);
0243 
0244 static struct msi_desc *msi_find_desc(struct msi_device_data *md, enum msi_desc_filter filter)
0245 {
0246     struct msi_desc *desc;
0247 
0248     xa_for_each_start(&md->__store, md->__iter_idx, desc, md->__iter_idx) {
0249         if (msi_desc_match(desc, filter))
0250             return desc;
0251     }
0252     md->__iter_idx = MSI_MAX_INDEX;
0253     return NULL;
0254 }
0255 
0256 /**
0257  * msi_first_desc - Get the first MSI descriptor of a device
0258  * @dev:    Device to operate on
0259  * @filter: Descriptor state filter
0260  *
0261  * Must be called with the MSI descriptor mutex held, i.e. msi_lock_descs()
0262  * must be invoked before the call.
0263  *
0264  * Return: Pointer to the first MSI descriptor matching the search
0265  *     criteria, NULL if none found.
0266  */
0267 struct msi_desc *msi_first_desc(struct device *dev, enum msi_desc_filter filter)
0268 {
0269     struct msi_device_data *md = dev->msi.data;
0270 
0271     if (WARN_ON_ONCE(!md))
0272         return NULL;
0273 
0274     lockdep_assert_held(&md->mutex);
0275 
0276     md->__iter_idx = 0;
0277     return msi_find_desc(md, filter);
0278 }
0279 EXPORT_SYMBOL_GPL(msi_first_desc);
0280 
0281 /**
0282  * msi_next_desc - Get the next MSI descriptor of a device
0283  * @dev:    Device to operate on
0284  *
0285  * The first invocation of msi_next_desc() has to be preceeded by a
0286  * successful invocation of __msi_first_desc(). Consecutive invocations are
0287  * only valid if the previous one was successful. All these operations have
0288  * to be done within the same MSI mutex held region.
0289  *
0290  * Return: Pointer to the next MSI descriptor matching the search
0291  *     criteria, NULL if none found.
0292  */
0293 struct msi_desc *msi_next_desc(struct device *dev, enum msi_desc_filter filter)
0294 {
0295     struct msi_device_data *md = dev->msi.data;
0296 
0297     if (WARN_ON_ONCE(!md))
0298         return NULL;
0299 
0300     lockdep_assert_held(&md->mutex);
0301 
0302     if (md->__iter_idx >= (unsigned long)MSI_MAX_INDEX)
0303         return NULL;
0304 
0305     md->__iter_idx++;
0306     return msi_find_desc(md, filter);
0307 }
0308 EXPORT_SYMBOL_GPL(msi_next_desc);
0309 
0310 /**
0311  * msi_get_virq - Return Linux interrupt number of a MSI interrupt
0312  * @dev:    Device to operate on
0313  * @index:  MSI interrupt index to look for (0-based)
0314  *
0315  * Return: The Linux interrupt number on success (> 0), 0 if not found
0316  */
0317 unsigned int msi_get_virq(struct device *dev, unsigned int index)
0318 {
0319     struct msi_desc *desc;
0320     unsigned int ret = 0;
0321     bool pcimsi;
0322 
0323     if (!dev->msi.data)
0324         return 0;
0325 
0326     pcimsi = dev_is_pci(dev) ? to_pci_dev(dev)->msi_enabled : false;
0327 
0328     msi_lock_descs(dev);
0329     desc = xa_load(&dev->msi.data->__store, pcimsi ? 0 : index);
0330     if (desc && desc->irq) {
0331         /*
0332          * PCI-MSI has only one descriptor for multiple interrupts.
0333          * PCI-MSIX and platform MSI use a descriptor per
0334          * interrupt.
0335          */
0336         if (pcimsi) {
0337             if (index < desc->nvec_used)
0338                 ret = desc->irq + index;
0339         } else {
0340             ret = desc->irq;
0341         }
0342     }
0343     msi_unlock_descs(dev);
0344     return ret;
0345 }
0346 EXPORT_SYMBOL_GPL(msi_get_virq);
0347 
0348 #ifdef CONFIG_SYSFS
0349 static struct attribute *msi_dev_attrs[] = {
0350     NULL
0351 };
0352 
0353 static const struct attribute_group msi_irqs_group = {
0354     .name   = "msi_irqs",
0355     .attrs  = msi_dev_attrs,
0356 };
0357 
0358 static inline int msi_sysfs_create_group(struct device *dev)
0359 {
0360     return devm_device_add_group(dev, &msi_irqs_group);
0361 }
0362 
0363 static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
0364                  char *buf)
0365 {
0366     /* MSI vs. MSIX is per device not per interrupt */
0367     bool is_msix = dev_is_pci(dev) ? to_pci_dev(dev)->msix_enabled : false;
0368 
0369     return sysfs_emit(buf, "%s\n", is_msix ? "msix" : "msi");
0370 }
0371 
0372 static void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc)
0373 {
0374     struct device_attribute *attrs = desc->sysfs_attrs;
0375     int i;
0376 
0377     if (!attrs)
0378         return;
0379 
0380     desc->sysfs_attrs = NULL;
0381     for (i = 0; i < desc->nvec_used; i++) {
0382         if (attrs[i].show)
0383             sysfs_remove_file_from_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
0384         kfree(attrs[i].attr.name);
0385     }
0386     kfree(attrs);
0387 }
0388 
0389 static int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc)
0390 {
0391     struct device_attribute *attrs;
0392     int ret, i;
0393 
0394     attrs = kcalloc(desc->nvec_used, sizeof(*attrs), GFP_KERNEL);
0395     if (!attrs)
0396         return -ENOMEM;
0397 
0398     desc->sysfs_attrs = attrs;
0399     for (i = 0; i < desc->nvec_used; i++) {
0400         sysfs_attr_init(&attrs[i].attr);
0401         attrs[i].attr.name = kasprintf(GFP_KERNEL, "%d", desc->irq + i);
0402         if (!attrs[i].attr.name) {
0403             ret = -ENOMEM;
0404             goto fail;
0405         }
0406 
0407         attrs[i].attr.mode = 0444;
0408         attrs[i].show = msi_mode_show;
0409 
0410         ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
0411         if (ret) {
0412             attrs[i].show = NULL;
0413             goto fail;
0414         }
0415     }
0416     return 0;
0417 
0418 fail:
0419     msi_sysfs_remove_desc(dev, desc);
0420     return ret;
0421 }
0422 
0423 #ifdef CONFIG_PCI_MSI_ARCH_FALLBACKS
0424 /**
0425  * msi_device_populate_sysfs - Populate msi_irqs sysfs entries for a device
0426  * @dev:    The device (PCI, platform etc) which will get sysfs entries
0427  */
0428 int msi_device_populate_sysfs(struct device *dev)
0429 {
0430     struct msi_desc *desc;
0431     int ret;
0432 
0433     msi_for_each_desc(desc, dev, MSI_DESC_ASSOCIATED) {
0434         if (desc->sysfs_attrs)
0435             continue;
0436         ret = msi_sysfs_populate_desc(dev, desc);
0437         if (ret)
0438             return ret;
0439     }
0440     return 0;
0441 }
0442 
0443 /**
0444  * msi_device_destroy_sysfs - Destroy msi_irqs sysfs entries for a device
0445  * @dev:        The device (PCI, platform etc) for which to remove
0446  *          sysfs entries
0447  */
0448 void msi_device_destroy_sysfs(struct device *dev)
0449 {
0450     struct msi_desc *desc;
0451 
0452     msi_for_each_desc(desc, dev, MSI_DESC_ALL)
0453         msi_sysfs_remove_desc(dev, desc);
0454 }
0455 #endif /* CONFIG_PCI_MSI_ARCH_FALLBACK */
0456 #else /* CONFIG_SYSFS */
0457 static inline int msi_sysfs_create_group(struct device *dev) { return 0; }
0458 static inline int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc) { return 0; }
0459 static inline void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc) { }
0460 #endif /* !CONFIG_SYSFS */
0461 
0462 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
0463 static inline void irq_chip_write_msi_msg(struct irq_data *data,
0464                       struct msi_msg *msg)
0465 {
0466     data->chip->irq_write_msi_msg(data, msg);
0467 }
0468 
0469 static void msi_check_level(struct irq_domain *domain, struct msi_msg *msg)
0470 {
0471     struct msi_domain_info *info = domain->host_data;
0472 
0473     /*
0474      * If the MSI provider has messed with the second message and
0475      * not advertized that it is level-capable, signal the breakage.
0476      */
0477     WARN_ON(!((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
0478           (info->chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)) &&
0479         (msg[1].address_lo || msg[1].address_hi || msg[1].data));
0480 }
0481 
0482 /**
0483  * msi_domain_set_affinity - Generic affinity setter function for MSI domains
0484  * @irq_data:   The irq data associated to the interrupt
0485  * @mask:   The affinity mask to set
0486  * @force:  Flag to enforce setting (disable online checks)
0487  *
0488  * Intended to be used by MSI interrupt controllers which are
0489  * implemented with hierarchical domains.
0490  *
0491  * Return: IRQ_SET_MASK_* result code
0492  */
0493 int msi_domain_set_affinity(struct irq_data *irq_data,
0494                 const struct cpumask *mask, bool force)
0495 {
0496     struct irq_data *parent = irq_data->parent_data;
0497     struct msi_msg msg[2] = { [1] = { }, };
0498     int ret;
0499 
0500     ret = parent->chip->irq_set_affinity(parent, mask, force);
0501     if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
0502         BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
0503         msi_check_level(irq_data->domain, msg);
0504         irq_chip_write_msi_msg(irq_data, msg);
0505     }
0506 
0507     return ret;
0508 }
0509 
0510 static int msi_domain_activate(struct irq_domain *domain,
0511                    struct irq_data *irq_data, bool early)
0512 {
0513     struct msi_msg msg[2] = { [1] = { }, };
0514 
0515     BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
0516     msi_check_level(irq_data->domain, msg);
0517     irq_chip_write_msi_msg(irq_data, msg);
0518     return 0;
0519 }
0520 
0521 static void msi_domain_deactivate(struct irq_domain *domain,
0522                   struct irq_data *irq_data)
0523 {
0524     struct msi_msg msg[2];
0525 
0526     memset(msg, 0, sizeof(msg));
0527     irq_chip_write_msi_msg(irq_data, msg);
0528 }
0529 
0530 static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
0531                 unsigned int nr_irqs, void *arg)
0532 {
0533     struct msi_domain_info *info = domain->host_data;
0534     struct msi_domain_ops *ops = info->ops;
0535     irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
0536     int i, ret;
0537 
0538     if (irq_find_mapping(domain, hwirq) > 0)
0539         return -EEXIST;
0540 
0541     if (domain->parent) {
0542         ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
0543         if (ret < 0)
0544             return ret;
0545     }
0546 
0547     for (i = 0; i < nr_irqs; i++) {
0548         ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
0549         if (ret < 0) {
0550             if (ops->msi_free) {
0551                 for (i--; i > 0; i--)
0552                     ops->msi_free(domain, info, virq + i);
0553             }
0554             irq_domain_free_irqs_top(domain, virq, nr_irqs);
0555             return ret;
0556         }
0557     }
0558 
0559     return 0;
0560 }
0561 
0562 static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
0563                 unsigned int nr_irqs)
0564 {
0565     struct msi_domain_info *info = domain->host_data;
0566     int i;
0567 
0568     if (info->ops->msi_free) {
0569         for (i = 0; i < nr_irqs; i++)
0570             info->ops->msi_free(domain, info, virq + i);
0571     }
0572     irq_domain_free_irqs_top(domain, virq, nr_irqs);
0573 }
0574 
0575 static const struct irq_domain_ops msi_domain_ops = {
0576     .alloc      = msi_domain_alloc,
0577     .free       = msi_domain_free,
0578     .activate   = msi_domain_activate,
0579     .deactivate = msi_domain_deactivate,
0580 };
0581 
0582 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
0583                         msi_alloc_info_t *arg)
0584 {
0585     return arg->hwirq;
0586 }
0587 
0588 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
0589                   int nvec, msi_alloc_info_t *arg)
0590 {
0591     memset(arg, 0, sizeof(*arg));
0592     return 0;
0593 }
0594 
0595 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
0596                     struct msi_desc *desc)
0597 {
0598     arg->desc = desc;
0599 }
0600 
0601 static int msi_domain_ops_init(struct irq_domain *domain,
0602                    struct msi_domain_info *info,
0603                    unsigned int virq, irq_hw_number_t hwirq,
0604                    msi_alloc_info_t *arg)
0605 {
0606     irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
0607                       info->chip_data);
0608     if (info->handler && info->handler_name) {
0609         __irq_set_handler(virq, info->handler, 0, info->handler_name);
0610         if (info->handler_data)
0611             irq_set_handler_data(virq, info->handler_data);
0612     }
0613     return 0;
0614 }
0615 
0616 static int msi_domain_ops_check(struct irq_domain *domain,
0617                 struct msi_domain_info *info,
0618                 struct device *dev)
0619 {
0620     return 0;
0621 }
0622 
0623 static struct msi_domain_ops msi_domain_ops_default = {
0624     .get_hwirq      = msi_domain_ops_get_hwirq,
0625     .msi_init       = msi_domain_ops_init,
0626     .msi_check      = msi_domain_ops_check,
0627     .msi_prepare        = msi_domain_ops_prepare,
0628     .set_desc       = msi_domain_ops_set_desc,
0629     .domain_alloc_irqs  = __msi_domain_alloc_irqs,
0630     .domain_free_irqs   = __msi_domain_free_irqs,
0631 };
0632 
0633 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
0634 {
0635     struct msi_domain_ops *ops = info->ops;
0636 
0637     if (ops == NULL) {
0638         info->ops = &msi_domain_ops_default;
0639         return;
0640     }
0641 
0642     if (ops->domain_alloc_irqs == NULL)
0643         ops->domain_alloc_irqs = msi_domain_ops_default.domain_alloc_irqs;
0644     if (ops->domain_free_irqs == NULL)
0645         ops->domain_free_irqs = msi_domain_ops_default.domain_free_irqs;
0646 
0647     if (!(info->flags & MSI_FLAG_USE_DEF_DOM_OPS))
0648         return;
0649 
0650     if (ops->get_hwirq == NULL)
0651         ops->get_hwirq = msi_domain_ops_default.get_hwirq;
0652     if (ops->msi_init == NULL)
0653         ops->msi_init = msi_domain_ops_default.msi_init;
0654     if (ops->msi_check == NULL)
0655         ops->msi_check = msi_domain_ops_default.msi_check;
0656     if (ops->msi_prepare == NULL)
0657         ops->msi_prepare = msi_domain_ops_default.msi_prepare;
0658     if (ops->set_desc == NULL)
0659         ops->set_desc = msi_domain_ops_default.set_desc;
0660 }
0661 
0662 static void msi_domain_update_chip_ops(struct msi_domain_info *info)
0663 {
0664     struct irq_chip *chip = info->chip;
0665 
0666     BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask);
0667     if (!chip->irq_set_affinity)
0668         chip->irq_set_affinity = msi_domain_set_affinity;
0669 }
0670 
0671 /**
0672  * msi_create_irq_domain - Create an MSI interrupt domain
0673  * @fwnode: Optional fwnode of the interrupt controller
0674  * @info:   MSI domain info
0675  * @parent: Parent irq domain
0676  *
0677  * Return: pointer to the created &struct irq_domain or %NULL on failure
0678  */
0679 struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
0680                      struct msi_domain_info *info,
0681                      struct irq_domain *parent)
0682 {
0683     struct irq_domain *domain;
0684 
0685     msi_domain_update_dom_ops(info);
0686     if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
0687         msi_domain_update_chip_ops(info);
0688 
0689     domain = irq_domain_create_hierarchy(parent, IRQ_DOMAIN_FLAG_MSI, 0,
0690                          fwnode, &msi_domain_ops, info);
0691 
0692     if (domain && !domain->name && info->chip)
0693         domain->name = info->chip->name;
0694 
0695     return domain;
0696 }
0697 
0698 int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
0699                 int nvec, msi_alloc_info_t *arg)
0700 {
0701     struct msi_domain_info *info = domain->host_data;
0702     struct msi_domain_ops *ops = info->ops;
0703     int ret;
0704 
0705     ret = ops->msi_check(domain, info, dev);
0706     if (ret == 0)
0707         ret = ops->msi_prepare(domain, dev, nvec, arg);
0708 
0709     return ret;
0710 }
0711 
0712 int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
0713                  int virq_base, int nvec, msi_alloc_info_t *arg)
0714 {
0715     struct msi_domain_info *info = domain->host_data;
0716     struct msi_domain_ops *ops = info->ops;
0717     struct msi_desc *desc;
0718     int ret, virq;
0719 
0720     msi_lock_descs(dev);
0721     ret = msi_add_simple_msi_descs(dev, virq_base, nvec);
0722     if (ret)
0723         goto unlock;
0724 
0725     for (virq = virq_base; virq < virq_base + nvec; virq++) {
0726         desc = xa_load(&dev->msi.data->__store, virq);
0727         desc->irq = virq;
0728 
0729         ops->set_desc(arg, desc);
0730         ret = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg);
0731         if (ret)
0732             goto fail;
0733 
0734         irq_set_msi_desc(virq, desc);
0735     }
0736     msi_unlock_descs(dev);
0737     return 0;
0738 
0739 fail:
0740     for (--virq; virq >= virq_base; virq--)
0741         irq_domain_free_irqs_common(domain, virq, 1);
0742     msi_free_msi_descs_range(dev, MSI_DESC_ALL, virq_base, virq_base + nvec - 1);
0743 unlock:
0744     msi_unlock_descs(dev);
0745     return ret;
0746 }
0747 
0748 /*
0749  * Carefully check whether the device can use reservation mode. If
0750  * reservation mode is enabled then the early activation will assign a
0751  * dummy vector to the device. If the PCI/MSI device does not support
0752  * masking of the entry then this can result in spurious interrupts when
0753  * the device driver is not absolutely careful. But even then a malfunction
0754  * of the hardware could result in a spurious interrupt on the dummy vector
0755  * and render the device unusable. If the entry can be masked then the core
0756  * logic will prevent the spurious interrupt and reservation mode can be
0757  * used. For now reservation mode is restricted to PCI/MSI.
0758  */
0759 static bool msi_check_reservation_mode(struct irq_domain *domain,
0760                        struct msi_domain_info *info,
0761                        struct device *dev)
0762 {
0763     struct msi_desc *desc;
0764 
0765     switch(domain->bus_token) {
0766     case DOMAIN_BUS_PCI_MSI:
0767     case DOMAIN_BUS_VMD_MSI:
0768         break;
0769     default:
0770         return false;
0771     }
0772 
0773     if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
0774         return false;
0775 
0776     if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_ignore_mask)
0777         return false;
0778 
0779     /*
0780      * Checking the first MSI descriptor is sufficient. MSIX supports
0781      * masking and MSI does so when the can_mask attribute is set.
0782      */
0783     desc = msi_first_desc(dev, MSI_DESC_ALL);
0784     return desc->pci.msi_attrib.is_msix || desc->pci.msi_attrib.can_mask;
0785 }
0786 
0787 static int msi_handle_pci_fail(struct irq_domain *domain, struct msi_desc *desc,
0788                    int allocated)
0789 {
0790     switch(domain->bus_token) {
0791     case DOMAIN_BUS_PCI_MSI:
0792     case DOMAIN_BUS_VMD_MSI:
0793         if (IS_ENABLED(CONFIG_PCI_MSI))
0794             break;
0795         fallthrough;
0796     default:
0797         return -ENOSPC;
0798     }
0799 
0800     /* Let a failed PCI multi MSI allocation retry */
0801     if (desc->nvec_used > 1)
0802         return 1;
0803 
0804     /* If there was a successful allocation let the caller know */
0805     return allocated ? allocated : -ENOSPC;
0806 }
0807 
0808 #define VIRQ_CAN_RESERVE    0x01
0809 #define VIRQ_ACTIVATE       0x02
0810 #define VIRQ_NOMASK_QUIRK   0x04
0811 
0812 static int msi_init_virq(struct irq_domain *domain, int virq, unsigned int vflags)
0813 {
0814     struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
0815     int ret;
0816 
0817     if (!(vflags & VIRQ_CAN_RESERVE)) {
0818         irqd_clr_can_reserve(irqd);
0819         if (vflags & VIRQ_NOMASK_QUIRK)
0820             irqd_set_msi_nomask_quirk(irqd);
0821 
0822         /*
0823          * If the interrupt is managed but no CPU is available to
0824          * service it, shut it down until better times. Note that
0825          * we only do this on the !RESERVE path as x86 (the only
0826          * architecture using this flag) deals with this in a
0827          * different way by using a catch-all vector.
0828          */
0829         if ((vflags & VIRQ_ACTIVATE) &&
0830             irqd_affinity_is_managed(irqd) &&
0831             !cpumask_intersects(irq_data_get_affinity_mask(irqd),
0832                     cpu_online_mask)) {
0833                 irqd_set_managed_shutdown(irqd);
0834                 return 0;
0835             }
0836     }
0837 
0838     if (!(vflags & VIRQ_ACTIVATE))
0839         return 0;
0840 
0841     ret = irq_domain_activate_irq(irqd, vflags & VIRQ_CAN_RESERVE);
0842     if (ret)
0843         return ret;
0844     /*
0845      * If the interrupt uses reservation mode, clear the activated bit
0846      * so request_irq() will assign the final vector.
0847      */
0848     if (vflags & VIRQ_CAN_RESERVE)
0849         irqd_clr_activated(irqd);
0850     return 0;
0851 }
0852 
0853 int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
0854                 int nvec)
0855 {
0856     struct msi_domain_info *info = domain->host_data;
0857     struct msi_domain_ops *ops = info->ops;
0858     msi_alloc_info_t arg = { };
0859     unsigned int vflags = 0;
0860     struct msi_desc *desc;
0861     int allocated = 0;
0862     int i, ret, virq;
0863 
0864     ret = msi_domain_prepare_irqs(domain, dev, nvec, &arg);
0865     if (ret)
0866         return ret;
0867 
0868     /*
0869      * This flag is set by the PCI layer as we need to activate
0870      * the MSI entries before the PCI layer enables MSI in the
0871      * card. Otherwise the card latches a random msi message.
0872      */
0873     if (info->flags & MSI_FLAG_ACTIVATE_EARLY)
0874         vflags |= VIRQ_ACTIVATE;
0875 
0876     /*
0877      * Interrupt can use a reserved vector and will not occupy
0878      * a real device vector until the interrupt is requested.
0879      */
0880     if (msi_check_reservation_mode(domain, info, dev)) {
0881         vflags |= VIRQ_CAN_RESERVE;
0882         /*
0883          * MSI affinity setting requires a special quirk (X86) when
0884          * reservation mode is active.
0885          */
0886         if (domain->flags & IRQ_DOMAIN_MSI_NOMASK_QUIRK)
0887             vflags |= VIRQ_NOMASK_QUIRK;
0888     }
0889 
0890     msi_for_each_desc(desc, dev, MSI_DESC_NOTASSOCIATED) {
0891         ops->set_desc(&arg, desc);
0892 
0893         virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
0894                            dev_to_node(dev), &arg, false,
0895                            desc->affinity);
0896         if (virq < 0)
0897             return msi_handle_pci_fail(domain, desc, allocated);
0898 
0899         for (i = 0; i < desc->nvec_used; i++) {
0900             irq_set_msi_desc_off(virq, i, desc);
0901             irq_debugfs_copy_devname(virq + i, dev);
0902             ret = msi_init_virq(domain, virq + i, vflags);
0903             if (ret)
0904                 return ret;
0905         }
0906         if (info->flags & MSI_FLAG_DEV_SYSFS) {
0907             ret = msi_sysfs_populate_desc(dev, desc);
0908             if (ret)
0909                 return ret;
0910         }
0911         allocated++;
0912     }
0913     return 0;
0914 }
0915 
0916 static int msi_domain_add_simple_msi_descs(struct msi_domain_info *info,
0917                        struct device *dev,
0918                        unsigned int num_descs)
0919 {
0920     if (!(info->flags & MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS))
0921         return 0;
0922 
0923     return msi_add_simple_msi_descs(dev, 0, num_descs);
0924 }
0925 
0926 /**
0927  * msi_domain_alloc_irqs_descs_locked - Allocate interrupts from a MSI interrupt domain
0928  * @domain: The domain to allocate from
0929  * @dev:    Pointer to device struct of the device for which the interrupts
0930  *      are allocated
0931  * @nvec:   The number of interrupts to allocate
0932  *
0933  * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
0934  * pair. Use this for MSI irqdomains which implement their own vector
0935  * allocation/free.
0936  *
0937  * Return: %0 on success or an error code.
0938  */
0939 int msi_domain_alloc_irqs_descs_locked(struct irq_domain *domain, struct device *dev,
0940                        int nvec)
0941 {
0942     struct msi_domain_info *info = domain->host_data;
0943     struct msi_domain_ops *ops = info->ops;
0944     int ret;
0945 
0946     lockdep_assert_held(&dev->msi.data->mutex);
0947 
0948     ret = msi_domain_add_simple_msi_descs(info, dev, nvec);
0949     if (ret)
0950         return ret;
0951 
0952     ret = ops->domain_alloc_irqs(domain, dev, nvec);
0953     if (ret)
0954         msi_domain_free_irqs_descs_locked(domain, dev);
0955     return ret;
0956 }
0957 
0958 /**
0959  * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
0960  * @domain: The domain to allocate from
0961  * @dev:    Pointer to device struct of the device for which the interrupts
0962  *      are allocated
0963  * @nvec:   The number of interrupts to allocate
0964  *
0965  * Return: %0 on success or an error code.
0966  */
0967 int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, int nvec)
0968 {
0969     int ret;
0970 
0971     msi_lock_descs(dev);
0972     ret = msi_domain_alloc_irqs_descs_locked(domain, dev, nvec);
0973     msi_unlock_descs(dev);
0974     return ret;
0975 }
0976 
0977 void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
0978 {
0979     struct msi_domain_info *info = domain->host_data;
0980     struct irq_data *irqd;
0981     struct msi_desc *desc;
0982     int i;
0983 
0984     /* Only handle MSI entries which have an interrupt associated */
0985     msi_for_each_desc(desc, dev, MSI_DESC_ASSOCIATED) {
0986         /* Make sure all interrupts are deactivated */
0987         for (i = 0; i < desc->nvec_used; i++) {
0988             irqd = irq_domain_get_irq_data(domain, desc->irq + i);
0989             if (irqd && irqd_is_activated(irqd))
0990                 irq_domain_deactivate_irq(irqd);
0991         }
0992 
0993         irq_domain_free_irqs(desc->irq, desc->nvec_used);
0994         if (info->flags & MSI_FLAG_DEV_SYSFS)
0995             msi_sysfs_remove_desc(dev, desc);
0996         desc->irq = 0;
0997     }
0998 }
0999 
1000 static void msi_domain_free_msi_descs(struct msi_domain_info *info,
1001                       struct device *dev)
1002 {
1003     if (info->flags & MSI_FLAG_FREE_MSI_DESCS)
1004         msi_free_msi_descs(dev);
1005 }
1006 
1007 /**
1008  * msi_domain_free_irqs_descs_locked - Free interrupts from a MSI interrupt @domain associated to @dev
1009  * @domain: The domain to managing the interrupts
1010  * @dev:    Pointer to device struct of the device for which the interrupts
1011  *      are free
1012  *
1013  * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
1014  * pair. Use this for MSI irqdomains which implement their own vector
1015  * allocation.
1016  */
1017 void msi_domain_free_irqs_descs_locked(struct irq_domain *domain, struct device *dev)
1018 {
1019     struct msi_domain_info *info = domain->host_data;
1020     struct msi_domain_ops *ops = info->ops;
1021 
1022     lockdep_assert_held(&dev->msi.data->mutex);
1023 
1024     ops->domain_free_irqs(domain, dev);
1025     msi_domain_free_msi_descs(info, dev);
1026 }
1027 
1028 /**
1029  * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated to @dev
1030  * @domain: The domain to managing the interrupts
1031  * @dev:    Pointer to device struct of the device for which the interrupts
1032  *      are free
1033  */
1034 void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
1035 {
1036     msi_lock_descs(dev);
1037     msi_domain_free_irqs_descs_locked(domain, dev);
1038     msi_unlock_descs(dev);
1039 }
1040 
1041 /**
1042  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
1043  * @domain: The interrupt domain to retrieve data from
1044  *
1045  * Return: the pointer to the msi_domain_info stored in @domain->host_data.
1046  */
1047 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
1048 {
1049     return (struct msi_domain_info *)domain->host_data;
1050 }
1051 
1052 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
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