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-rw-r--r--kernel/irq/msi.c1042
1 files changed, 1042 insertions, 0 deletions
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
new file mode 100644
index 000000000..4e462b5f7
--- /dev/null
+++ b/kernel/irq/msi.c
@@ -0,0 +1,1042 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014 Intel Corp.
+ * Author: Jiang Liu <jiang.liu@linux.intel.com>
+ *
+ * This file is licensed under GPLv2.
+ *
+ * This file contains common code to support Message Signaled Interrupts for
+ * PCI compatible and non PCI compatible devices.
+ */
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/pci.h>
+
+#include "internals.h"
+
+static inline int msi_sysfs_create_group(struct device *dev);
+
+/**
+ * msi_alloc_desc - Allocate an initialized msi_desc
+ * @dev: Pointer to the device for which this is allocated
+ * @nvec: The number of vectors used in this entry
+ * @affinity: Optional pointer to an affinity mask array size of @nvec
+ *
+ * If @affinity is not %NULL then an affinity array[@nvec] is allocated
+ * and the affinity masks and flags from @affinity are copied.
+ *
+ * Return: pointer to allocated &msi_desc on success or %NULL on failure
+ */
+static struct msi_desc *msi_alloc_desc(struct device *dev, int nvec,
+ const struct irq_affinity_desc *affinity)
+{
+ struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+
+ if (!desc)
+ return NULL;
+
+ desc->dev = dev;
+ desc->nvec_used = nvec;
+ if (affinity) {
+ desc->affinity = kmemdup(affinity, nvec * sizeof(*desc->affinity), GFP_KERNEL);
+ if (!desc->affinity) {
+ kfree(desc);
+ return NULL;
+ }
+ }
+ return desc;
+}
+
+static void msi_free_desc(struct msi_desc *desc)
+{
+ kfree(desc->affinity);
+ kfree(desc);
+}
+
+static int msi_insert_desc(struct msi_device_data *md, struct msi_desc *desc, unsigned int index)
+{
+ int ret;
+
+ desc->msi_index = index;
+ ret = xa_insert(&md->__store, index, desc, GFP_KERNEL);
+ if (ret)
+ msi_free_desc(desc);
+ return ret;
+}
+
+/**
+ * msi_add_msi_desc - Allocate and initialize a MSI descriptor
+ * @dev: Pointer to the device for which the descriptor is allocated
+ * @init_desc: Pointer to an MSI descriptor to initialize the new descriptor
+ *
+ * Return: 0 on success or an appropriate failure code.
+ */
+int msi_add_msi_desc(struct device *dev, struct msi_desc *init_desc)
+{
+ struct msi_desc *desc;
+
+ lockdep_assert_held(&dev->msi.data->mutex);
+
+ desc = msi_alloc_desc(dev, init_desc->nvec_used, init_desc->affinity);
+ if (!desc)
+ return -ENOMEM;
+
+ /* Copy type specific data to the new descriptor. */
+ desc->pci = init_desc->pci;
+ return msi_insert_desc(dev->msi.data, desc, init_desc->msi_index);
+}
+
+/**
+ * msi_add_simple_msi_descs - Allocate and initialize MSI descriptors
+ * @dev: Pointer to the device for which the descriptors are allocated
+ * @index: Index for the first MSI descriptor
+ * @ndesc: Number of descriptors to allocate
+ *
+ * Return: 0 on success or an appropriate failure code.
+ */
+static int msi_add_simple_msi_descs(struct device *dev, unsigned int index, unsigned int ndesc)
+{
+ unsigned int idx, last = index + ndesc - 1;
+ struct msi_desc *desc;
+ int ret;
+
+ lockdep_assert_held(&dev->msi.data->mutex);
+
+ for (idx = index; idx <= last; idx++) {
+ desc = msi_alloc_desc(dev, 1, NULL);
+ if (!desc)
+ goto fail_mem;
+ ret = msi_insert_desc(dev->msi.data, desc, idx);
+ if (ret)
+ goto fail;
+ }
+ return 0;
+
+fail_mem:
+ ret = -ENOMEM;
+fail:
+ msi_free_msi_descs_range(dev, MSI_DESC_NOTASSOCIATED, index, last);
+ return ret;
+}
+
+static bool msi_desc_match(struct msi_desc *desc, enum msi_desc_filter filter)
+{
+ switch (filter) {
+ case MSI_DESC_ALL:
+ return true;
+ case MSI_DESC_NOTASSOCIATED:
+ return !desc->irq;
+ case MSI_DESC_ASSOCIATED:
+ return !!desc->irq;
+ }
+ WARN_ON_ONCE(1);
+ return false;
+}
+
+/**
+ * msi_free_msi_descs_range - Free MSI descriptors of a device
+ * @dev: Device to free the descriptors
+ * @filter: Descriptor state filter
+ * @first_index: Index to start freeing from
+ * @last_index: Last index to be freed
+ */
+void msi_free_msi_descs_range(struct device *dev, enum msi_desc_filter filter,
+ unsigned int first_index, unsigned int last_index)
+{
+ struct xarray *xa = &dev->msi.data->__store;
+ struct msi_desc *desc;
+ unsigned long idx;
+
+ lockdep_assert_held(&dev->msi.data->mutex);
+
+ xa_for_each_range(xa, idx, desc, first_index, last_index) {
+ if (msi_desc_match(desc, filter)) {
+ xa_erase(xa, idx);
+ msi_free_desc(desc);
+ }
+ }
+}
+
+void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
+{
+ *msg = entry->msg;
+}
+
+void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
+{
+ struct msi_desc *entry = irq_get_msi_desc(irq);
+
+ __get_cached_msi_msg(entry, msg);
+}
+EXPORT_SYMBOL_GPL(get_cached_msi_msg);
+
+static void msi_device_data_release(struct device *dev, void *res)
+{
+ struct msi_device_data *md = res;
+
+ WARN_ON_ONCE(!xa_empty(&md->__store));
+ xa_destroy(&md->__store);
+ dev->msi.data = NULL;
+}
+
+/**
+ * msi_setup_device_data - Setup MSI device data
+ * @dev: Device for which MSI device data should be set up
+ *
+ * Return: 0 on success, appropriate error code otherwise
+ *
+ * This can be called more than once for @dev. If the MSI device data is
+ * already allocated the call succeeds. The allocated memory is
+ * automatically released when the device is destroyed.
+ */
+int msi_setup_device_data(struct device *dev)
+{
+ struct msi_device_data *md;
+ int ret;
+
+ if (dev->msi.data)
+ return 0;
+
+ md = devres_alloc(msi_device_data_release, sizeof(*md), GFP_KERNEL);
+ if (!md)
+ return -ENOMEM;
+
+ ret = msi_sysfs_create_group(dev);
+ if (ret) {
+ devres_free(md);
+ return ret;
+ }
+
+ xa_init(&md->__store);
+ mutex_init(&md->mutex);
+ dev->msi.data = md;
+ devres_add(dev, md);
+ return 0;
+}
+
+/**
+ * msi_lock_descs - Lock the MSI descriptor storage of a device
+ * @dev: Device to operate on
+ */
+void msi_lock_descs(struct device *dev)
+{
+ mutex_lock(&dev->msi.data->mutex);
+}
+EXPORT_SYMBOL_GPL(msi_lock_descs);
+
+/**
+ * msi_unlock_descs - Unlock the MSI descriptor storage of a device
+ * @dev: Device to operate on
+ */
+void msi_unlock_descs(struct device *dev)
+{
+ /* Invalidate the index wich was cached by the iterator */
+ dev->msi.data->__iter_idx = MSI_MAX_INDEX;
+ mutex_unlock(&dev->msi.data->mutex);
+}
+EXPORT_SYMBOL_GPL(msi_unlock_descs);
+
+static struct msi_desc *msi_find_desc(struct msi_device_data *md, enum msi_desc_filter filter)
+{
+ struct msi_desc *desc;
+
+ xa_for_each_start(&md->__store, md->__iter_idx, desc, md->__iter_idx) {
+ if (msi_desc_match(desc, filter))
+ return desc;
+ }
+ md->__iter_idx = MSI_MAX_INDEX;
+ return NULL;
+}
+
+/**
+ * msi_first_desc - Get the first MSI descriptor of a device
+ * @dev: Device to operate on
+ * @filter: Descriptor state filter
+ *
+ * Must be called with the MSI descriptor mutex held, i.e. msi_lock_descs()
+ * must be invoked before the call.
+ *
+ * Return: Pointer to the first MSI descriptor matching the search
+ * criteria, NULL if none found.
+ */
+struct msi_desc *msi_first_desc(struct device *dev, enum msi_desc_filter filter)
+{
+ struct msi_device_data *md = dev->msi.data;
+
+ if (WARN_ON_ONCE(!md))
+ return NULL;
+
+ lockdep_assert_held(&md->mutex);
+
+ md->__iter_idx = 0;
+ return msi_find_desc(md, filter);
+}
+EXPORT_SYMBOL_GPL(msi_first_desc);
+
+/**
+ * msi_next_desc - Get the next MSI descriptor of a device
+ * @dev: Device to operate on
+ *
+ * The first invocation of msi_next_desc() has to be preceeded by a
+ * successful invocation of __msi_first_desc(). Consecutive invocations are
+ * only valid if the previous one was successful. All these operations have
+ * to be done within the same MSI mutex held region.
+ *
+ * Return: Pointer to the next MSI descriptor matching the search
+ * criteria, NULL if none found.
+ */
+struct msi_desc *msi_next_desc(struct device *dev, enum msi_desc_filter filter)
+{
+ struct msi_device_data *md = dev->msi.data;
+
+ if (WARN_ON_ONCE(!md))
+ return NULL;
+
+ lockdep_assert_held(&md->mutex);
+
+ if (md->__iter_idx >= (unsigned long)MSI_MAX_INDEX)
+ return NULL;
+
+ md->__iter_idx++;
+ return msi_find_desc(md, filter);
+}
+EXPORT_SYMBOL_GPL(msi_next_desc);
+
+/**
+ * msi_get_virq - Return Linux interrupt number of a MSI interrupt
+ * @dev: Device to operate on
+ * @index: MSI interrupt index to look for (0-based)
+ *
+ * Return: The Linux interrupt number on success (> 0), 0 if not found
+ */
+unsigned int msi_get_virq(struct device *dev, unsigned int index)
+{
+ struct msi_desc *desc;
+ unsigned int ret = 0;
+ bool pcimsi;
+
+ if (!dev->msi.data)
+ return 0;
+
+ pcimsi = dev_is_pci(dev) ? to_pci_dev(dev)->msi_enabled : false;
+
+ msi_lock_descs(dev);
+ desc = xa_load(&dev->msi.data->__store, pcimsi ? 0 : index);
+ if (desc && desc->irq) {
+ /*
+ * PCI-MSI has only one descriptor for multiple interrupts.
+ * PCI-MSIX and platform MSI use a descriptor per
+ * interrupt.
+ */
+ if (pcimsi) {
+ if (index < desc->nvec_used)
+ ret = desc->irq + index;
+ } else {
+ ret = desc->irq;
+ }
+ }
+ msi_unlock_descs(dev);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(msi_get_virq);
+
+#ifdef CONFIG_SYSFS
+static struct attribute *msi_dev_attrs[] = {
+ NULL
+};
+
+static const struct attribute_group msi_irqs_group = {
+ .name = "msi_irqs",
+ .attrs = msi_dev_attrs,
+};
+
+static inline int msi_sysfs_create_group(struct device *dev)
+{
+ return devm_device_add_group(dev, &msi_irqs_group);
+}
+
+static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ /* MSI vs. MSIX is per device not per interrupt */
+ bool is_msix = dev_is_pci(dev) ? to_pci_dev(dev)->msix_enabled : false;
+
+ return sysfs_emit(buf, "%s\n", is_msix ? "msix" : "msi");
+}
+
+static void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc)
+{
+ struct device_attribute *attrs = desc->sysfs_attrs;
+ int i;
+
+ if (!attrs)
+ return;
+
+ desc->sysfs_attrs = NULL;
+ for (i = 0; i < desc->nvec_used; i++) {
+ if (attrs[i].show)
+ sysfs_remove_file_from_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
+ kfree(attrs[i].attr.name);
+ }
+ kfree(attrs);
+}
+
+static int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc)
+{
+ struct device_attribute *attrs;
+ int ret, i;
+
+ attrs = kcalloc(desc->nvec_used, sizeof(*attrs), GFP_KERNEL);
+ if (!attrs)
+ return -ENOMEM;
+
+ desc->sysfs_attrs = attrs;
+ for (i = 0; i < desc->nvec_used; i++) {
+ sysfs_attr_init(&attrs[i].attr);
+ attrs[i].attr.name = kasprintf(GFP_KERNEL, "%d", desc->irq + i);
+ if (!attrs[i].attr.name) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ attrs[i].attr.mode = 0444;
+ attrs[i].show = msi_mode_show;
+
+ ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
+ if (ret) {
+ attrs[i].show = NULL;
+ goto fail;
+ }
+ }
+ return 0;
+
+fail:
+ msi_sysfs_remove_desc(dev, desc);
+ return ret;
+}
+
+#if defined(CONFIG_PCI_MSI_ARCH_FALLBACKS) || defined(CONFIG_PCI_XEN)
+/**
+ * msi_device_populate_sysfs - Populate msi_irqs sysfs entries for a device
+ * @dev: The device (PCI, platform etc) which will get sysfs entries
+ */
+int msi_device_populate_sysfs(struct device *dev)
+{
+ struct msi_desc *desc;
+ int ret;
+
+ msi_for_each_desc(desc, dev, MSI_DESC_ASSOCIATED) {
+ if (desc->sysfs_attrs)
+ continue;
+ ret = msi_sysfs_populate_desc(dev, desc);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+/**
+ * msi_device_destroy_sysfs - Destroy msi_irqs sysfs entries for a device
+ * @dev: The device (PCI, platform etc) for which to remove
+ * sysfs entries
+ */
+void msi_device_destroy_sysfs(struct device *dev)
+{
+ struct msi_desc *desc;
+
+ msi_for_each_desc(desc, dev, MSI_DESC_ALL)
+ msi_sysfs_remove_desc(dev, desc);
+}
+#endif /* CONFIG_PCI_MSI_ARCH_FALLBACK || CONFIG_PCI_XEN */
+#else /* CONFIG_SYSFS */
+static inline int msi_sysfs_create_group(struct device *dev) { return 0; }
+static inline int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc) { return 0; }
+static inline void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc) { }
+#endif /* !CONFIG_SYSFS */
+
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+static inline void irq_chip_write_msi_msg(struct irq_data *data,
+ struct msi_msg *msg)
+{
+ data->chip->irq_write_msi_msg(data, msg);
+}
+
+static void msi_check_level(struct irq_domain *domain, struct msi_msg *msg)
+{
+ struct msi_domain_info *info = domain->host_data;
+
+ /*
+ * If the MSI provider has messed with the second message and
+ * not advertized that it is level-capable, signal the breakage.
+ */
+ WARN_ON(!((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
+ (info->chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)) &&
+ (msg[1].address_lo || msg[1].address_hi || msg[1].data));
+}
+
+/**
+ * msi_domain_set_affinity - Generic affinity setter function for MSI domains
+ * @irq_data: The irq data associated to the interrupt
+ * @mask: The affinity mask to set
+ * @force: Flag to enforce setting (disable online checks)
+ *
+ * Intended to be used by MSI interrupt controllers which are
+ * implemented with hierarchical domains.
+ *
+ * Return: IRQ_SET_MASK_* result code
+ */
+int msi_domain_set_affinity(struct irq_data *irq_data,
+ const struct cpumask *mask, bool force)
+{
+ struct irq_data *parent = irq_data->parent_data;
+ struct msi_msg msg[2] = { [1] = { }, };
+ int ret;
+
+ ret = parent->chip->irq_set_affinity(parent, mask, force);
+ if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
+ BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
+ msi_check_level(irq_data->domain, msg);
+ irq_chip_write_msi_msg(irq_data, msg);
+ }
+
+ return ret;
+}
+
+static int msi_domain_activate(struct irq_domain *domain,
+ struct irq_data *irq_data, bool early)
+{
+ struct msi_msg msg[2] = { [1] = { }, };
+
+ BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
+ msi_check_level(irq_data->domain, msg);
+ irq_chip_write_msi_msg(irq_data, msg);
+ return 0;
+}
+
+static void msi_domain_deactivate(struct irq_domain *domain,
+ struct irq_data *irq_data)
+{
+ struct msi_msg msg[2];
+
+ memset(msg, 0, sizeof(msg));
+ irq_chip_write_msi_msg(irq_data, msg);
+}
+
+static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+ irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
+ int i, ret;
+
+ if (irq_find_mapping(domain, hwirq) > 0)
+ return -EEXIST;
+
+ if (domain->parent) {
+ ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
+ if (ret < 0)
+ return ret;
+ }
+
+ for (i = 0; i < nr_irqs; i++) {
+ ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
+ if (ret < 0) {
+ if (ops->msi_free) {
+ for (i--; i > 0; i--)
+ ops->msi_free(domain, info, virq + i);
+ }
+ irq_domain_free_irqs_top(domain, virq, nr_irqs);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs)
+{
+ struct msi_domain_info *info = domain->host_data;
+ int i;
+
+ if (info->ops->msi_free) {
+ for (i = 0; i < nr_irqs; i++)
+ info->ops->msi_free(domain, info, virq + i);
+ }
+ irq_domain_free_irqs_top(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+ .alloc = msi_domain_alloc,
+ .free = msi_domain_free,
+ .activate = msi_domain_activate,
+ .deactivate = msi_domain_deactivate,
+};
+
+static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
+ msi_alloc_info_t *arg)
+{
+ return arg->hwirq;
+}
+
+static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
+ int nvec, msi_alloc_info_t *arg)
+{
+ memset(arg, 0, sizeof(*arg));
+ return 0;
+}
+
+static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
+ struct msi_desc *desc)
+{
+ arg->desc = desc;
+}
+
+static int msi_domain_ops_init(struct irq_domain *domain,
+ struct msi_domain_info *info,
+ unsigned int virq, irq_hw_number_t hwirq,
+ msi_alloc_info_t *arg)
+{
+ irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
+ info->chip_data);
+ if (info->handler && info->handler_name) {
+ __irq_set_handler(virq, info->handler, 0, info->handler_name);
+ if (info->handler_data)
+ irq_set_handler_data(virq, info->handler_data);
+ }
+ return 0;
+}
+
+static int msi_domain_ops_check(struct irq_domain *domain,
+ struct msi_domain_info *info,
+ struct device *dev)
+{
+ return 0;
+}
+
+static struct msi_domain_ops msi_domain_ops_default = {
+ .get_hwirq = msi_domain_ops_get_hwirq,
+ .msi_init = msi_domain_ops_init,
+ .msi_check = msi_domain_ops_check,
+ .msi_prepare = msi_domain_ops_prepare,
+ .set_desc = msi_domain_ops_set_desc,
+ .domain_alloc_irqs = __msi_domain_alloc_irqs,
+ .domain_free_irqs = __msi_domain_free_irqs,
+};
+
+static void msi_domain_update_dom_ops(struct msi_domain_info *info)
+{
+ struct msi_domain_ops *ops = info->ops;
+
+ if (ops == NULL) {
+ info->ops = &msi_domain_ops_default;
+ return;
+ }
+
+ if (ops->domain_alloc_irqs == NULL)
+ ops->domain_alloc_irqs = msi_domain_ops_default.domain_alloc_irqs;
+ if (ops->domain_free_irqs == NULL)
+ ops->domain_free_irqs = msi_domain_ops_default.domain_free_irqs;
+
+ if (!(info->flags & MSI_FLAG_USE_DEF_DOM_OPS))
+ return;
+
+ if (ops->get_hwirq == NULL)
+ ops->get_hwirq = msi_domain_ops_default.get_hwirq;
+ if (ops->msi_init == NULL)
+ ops->msi_init = msi_domain_ops_default.msi_init;
+ if (ops->msi_check == NULL)
+ ops->msi_check = msi_domain_ops_default.msi_check;
+ if (ops->msi_prepare == NULL)
+ ops->msi_prepare = msi_domain_ops_default.msi_prepare;
+ if (ops->set_desc == NULL)
+ ops->set_desc = msi_domain_ops_default.set_desc;
+}
+
+static void msi_domain_update_chip_ops(struct msi_domain_info *info)
+{
+ struct irq_chip *chip = info->chip;
+
+ BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask);
+ if (!chip->irq_set_affinity)
+ chip->irq_set_affinity = msi_domain_set_affinity;
+}
+
+/**
+ * msi_create_irq_domain - Create an MSI interrupt domain
+ * @fwnode: Optional fwnode of the interrupt controller
+ * @info: MSI domain info
+ * @parent: Parent irq domain
+ *
+ * Return: pointer to the created &struct irq_domain or %NULL on failure
+ */
+struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
+ struct msi_domain_info *info,
+ struct irq_domain *parent)
+{
+ struct irq_domain *domain;
+
+ msi_domain_update_dom_ops(info);
+ if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
+ msi_domain_update_chip_ops(info);
+
+ domain = irq_domain_create_hierarchy(parent, IRQ_DOMAIN_FLAG_MSI, 0,
+ fwnode, &msi_domain_ops, info);
+
+ if (domain && !domain->name && info->chip)
+ domain->name = info->chip->name;
+
+ return domain;
+}
+
+int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
+ int nvec, msi_alloc_info_t *arg)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+ int ret;
+
+ ret = ops->msi_check(domain, info, dev);
+ if (ret == 0)
+ ret = ops->msi_prepare(domain, dev, nvec, arg);
+
+ return ret;
+}
+
+int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
+ int virq_base, int nvec, msi_alloc_info_t *arg)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+ struct msi_desc *desc;
+ int ret, virq;
+
+ msi_lock_descs(dev);
+ ret = msi_add_simple_msi_descs(dev, virq_base, nvec);
+ if (ret)
+ goto unlock;
+
+ for (virq = virq_base; virq < virq_base + nvec; virq++) {
+ desc = xa_load(&dev->msi.data->__store, virq);
+ desc->irq = virq;
+
+ ops->set_desc(arg, desc);
+ ret = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg);
+ if (ret)
+ goto fail;
+
+ irq_set_msi_desc(virq, desc);
+ }
+ msi_unlock_descs(dev);
+ return 0;
+
+fail:
+ for (--virq; virq >= virq_base; virq--)
+ irq_domain_free_irqs_common(domain, virq, 1);
+ msi_free_msi_descs_range(dev, MSI_DESC_ALL, virq_base, virq_base + nvec - 1);
+unlock:
+ msi_unlock_descs(dev);
+ return ret;
+}
+
+/*
+ * Carefully check whether the device can use reservation mode. If
+ * reservation mode is enabled then the early activation will assign a
+ * dummy vector to the device. If the PCI/MSI device does not support
+ * masking of the entry then this can result in spurious interrupts when
+ * the device driver is not absolutely careful. But even then a malfunction
+ * of the hardware could result in a spurious interrupt on the dummy vector
+ * and render the device unusable. If the entry can be masked then the core
+ * logic will prevent the spurious interrupt and reservation mode can be
+ * used. For now reservation mode is restricted to PCI/MSI.
+ */
+static bool msi_check_reservation_mode(struct irq_domain *domain,
+ struct msi_domain_info *info,
+ struct device *dev)
+{
+ struct msi_desc *desc;
+
+ switch(domain->bus_token) {
+ case DOMAIN_BUS_PCI_MSI:
+ case DOMAIN_BUS_VMD_MSI:
+ break;
+ default:
+ return false;
+ }
+
+ if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
+ return false;
+
+ if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_ignore_mask)
+ return false;
+
+ /*
+ * Checking the first MSI descriptor is sufficient. MSIX supports
+ * masking and MSI does so when the can_mask attribute is set.
+ */
+ desc = msi_first_desc(dev, MSI_DESC_ALL);
+ return desc->pci.msi_attrib.is_msix || desc->pci.msi_attrib.can_mask;
+}
+
+static int msi_handle_pci_fail(struct irq_domain *domain, struct msi_desc *desc,
+ int allocated)
+{
+ switch(domain->bus_token) {
+ case DOMAIN_BUS_PCI_MSI:
+ case DOMAIN_BUS_VMD_MSI:
+ if (IS_ENABLED(CONFIG_PCI_MSI))
+ break;
+ fallthrough;
+ default:
+ return -ENOSPC;
+ }
+
+ /* Let a failed PCI multi MSI allocation retry */
+ if (desc->nvec_used > 1)
+ return 1;
+
+ /* If there was a successful allocation let the caller know */
+ return allocated ? allocated : -ENOSPC;
+}
+
+#define VIRQ_CAN_RESERVE 0x01
+#define VIRQ_ACTIVATE 0x02
+
+static int msi_init_virq(struct irq_domain *domain, int virq, unsigned int vflags)
+{
+ struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
+ int ret;
+
+ if (!(vflags & VIRQ_CAN_RESERVE)) {
+ irqd_clr_can_reserve(irqd);
+
+ /*
+ * If the interrupt is managed but no CPU is available to
+ * service it, shut it down until better times. Note that
+ * we only do this on the !RESERVE path as x86 (the only
+ * architecture using this flag) deals with this in a
+ * different way by using a catch-all vector.
+ */
+ if ((vflags & VIRQ_ACTIVATE) &&
+ irqd_affinity_is_managed(irqd) &&
+ !cpumask_intersects(irq_data_get_affinity_mask(irqd),
+ cpu_online_mask)) {
+ irqd_set_managed_shutdown(irqd);
+ return 0;
+ }
+ }
+
+ if (!(vflags & VIRQ_ACTIVATE))
+ return 0;
+
+ ret = irq_domain_activate_irq(irqd, vflags & VIRQ_CAN_RESERVE);
+ if (ret)
+ return ret;
+ /*
+ * If the interrupt uses reservation mode, clear the activated bit
+ * so request_irq() will assign the final vector.
+ */
+ if (vflags & VIRQ_CAN_RESERVE)
+ irqd_clr_activated(irqd);
+ return 0;
+}
+
+int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+ int nvec)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+ msi_alloc_info_t arg = { };
+ unsigned int vflags = 0;
+ struct msi_desc *desc;
+ int allocated = 0;
+ int i, ret, virq;
+
+ ret = msi_domain_prepare_irqs(domain, dev, nvec, &arg);
+ if (ret)
+ return ret;
+
+ /*
+ * This flag is set by the PCI layer as we need to activate
+ * the MSI entries before the PCI layer enables MSI in the
+ * card. Otherwise the card latches a random msi message.
+ */
+ if (info->flags & MSI_FLAG_ACTIVATE_EARLY)
+ vflags |= VIRQ_ACTIVATE;
+
+ /*
+ * Interrupt can use a reserved vector and will not occupy
+ * a real device vector until the interrupt is requested.
+ */
+ if (msi_check_reservation_mode(domain, info, dev))
+ vflags |= VIRQ_CAN_RESERVE;
+
+ msi_for_each_desc(desc, dev, MSI_DESC_NOTASSOCIATED) {
+ ops->set_desc(&arg, desc);
+
+ virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
+ dev_to_node(dev), &arg, false,
+ desc->affinity);
+ if (virq < 0)
+ return msi_handle_pci_fail(domain, desc, allocated);
+
+ for (i = 0; i < desc->nvec_used; i++) {
+ irq_set_msi_desc_off(virq, i, desc);
+ irq_debugfs_copy_devname(virq + i, dev);
+ ret = msi_init_virq(domain, virq + i, vflags);
+ if (ret)
+ return ret;
+ }
+ if (info->flags & MSI_FLAG_DEV_SYSFS) {
+ ret = msi_sysfs_populate_desc(dev, desc);
+ if (ret)
+ return ret;
+ }
+ allocated++;
+ }
+ return 0;
+}
+
+static int msi_domain_add_simple_msi_descs(struct msi_domain_info *info,
+ struct device *dev,
+ unsigned int num_descs)
+{
+ if (!(info->flags & MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS))
+ return 0;
+
+ return msi_add_simple_msi_descs(dev, 0, num_descs);
+}
+
+/**
+ * msi_domain_alloc_irqs_descs_locked - Allocate interrupts from a MSI interrupt domain
+ * @domain: The domain to allocate from
+ * @dev: Pointer to device struct of the device for which the interrupts
+ * are allocated
+ * @nvec: The number of interrupts to allocate
+ *
+ * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
+ * pair. Use this for MSI irqdomains which implement their own vector
+ * allocation/free.
+ *
+ * Return: %0 on success or an error code.
+ */
+int msi_domain_alloc_irqs_descs_locked(struct irq_domain *domain, struct device *dev,
+ int nvec)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+ int ret;
+
+ lockdep_assert_held(&dev->msi.data->mutex);
+
+ ret = msi_domain_add_simple_msi_descs(info, dev, nvec);
+ if (ret)
+ return ret;
+
+ ret = ops->domain_alloc_irqs(domain, dev, nvec);
+ if (ret)
+ msi_domain_free_irqs_descs_locked(domain, dev);
+ return ret;
+}
+
+/**
+ * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
+ * @domain: The domain to allocate from
+ * @dev: Pointer to device struct of the device for which the interrupts
+ * are allocated
+ * @nvec: The number of interrupts to allocate
+ *
+ * Return: %0 on success or an error code.
+ */
+int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, int nvec)
+{
+ int ret;
+
+ msi_lock_descs(dev);
+ ret = msi_domain_alloc_irqs_descs_locked(domain, dev, nvec);
+ msi_unlock_descs(dev);
+ return ret;
+}
+
+void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct irq_data *irqd;
+ struct msi_desc *desc;
+ int i;
+
+ /* Only handle MSI entries which have an interrupt associated */
+ msi_for_each_desc(desc, dev, MSI_DESC_ASSOCIATED) {
+ /* Make sure all interrupts are deactivated */
+ for (i = 0; i < desc->nvec_used; i++) {
+ irqd = irq_domain_get_irq_data(domain, desc->irq + i);
+ if (irqd && irqd_is_activated(irqd))
+ irq_domain_deactivate_irq(irqd);
+ }
+
+ irq_domain_free_irqs(desc->irq, desc->nvec_used);
+ if (info->flags & MSI_FLAG_DEV_SYSFS)
+ msi_sysfs_remove_desc(dev, desc);
+ desc->irq = 0;
+ }
+}
+
+static void msi_domain_free_msi_descs(struct msi_domain_info *info,
+ struct device *dev)
+{
+ if (info->flags & MSI_FLAG_FREE_MSI_DESCS)
+ msi_free_msi_descs(dev);
+}
+
+/**
+ * msi_domain_free_irqs_descs_locked - Free interrupts from a MSI interrupt @domain associated to @dev
+ * @domain: The domain to managing the interrupts
+ * @dev: Pointer to device struct of the device for which the interrupts
+ * are free
+ *
+ * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
+ * pair. Use this for MSI irqdomains which implement their own vector
+ * allocation.
+ */
+void msi_domain_free_irqs_descs_locked(struct irq_domain *domain, struct device *dev)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+
+ lockdep_assert_held(&dev->msi.data->mutex);
+
+ ops->domain_free_irqs(domain, dev);
+ msi_domain_free_msi_descs(info, dev);
+}
+
+/**
+ * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated to @dev
+ * @domain: The domain to managing the interrupts
+ * @dev: Pointer to device struct of the device for which the interrupts
+ * are free
+ */
+void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+{
+ msi_lock_descs(dev);
+ msi_domain_free_irqs_descs_locked(domain, dev);
+ msi_unlock_descs(dev);
+}
+
+/**
+ * msi_get_domain_info - Get the MSI interrupt domain info for @domain
+ * @domain: The interrupt domain to retrieve data from
+ *
+ * Return: the pointer to the msi_domain_info stored in @domain->host_data.
+ */
+struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
+{
+ return (struct msi_domain_info *)domain->host_data;
+}
+
+#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */