Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1631 insertions, 0 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
new file mode 100644
index 000000000..3da69b26e
--- /dev/null
+++ b/drivers/pci/msi.c
@@ -0,0 +1,1631 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Message Signaled Interrupt (MSI)
+ *
+ * Copyright (C) 2003-2004 Intel
+ * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
+ * Copyright (C) 2016 Christoph Hellwig.
+ */
+
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/export.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/proc_fs.h>
+#include <linux/msi.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/acpi_iort.h>
+#include <linux/slab.h>
+#include <linux/irqdomain.h>
+#include <linux/of_irq.h>
+
+#include "pci.h"
+
+static int pci_msi_enable = 1;
+int pci_msi_ignore_mask;
+
+#define msix_table_size(flags)	((flags & PCI_MSIX_FLAGS_QSIZE) + 1)
+
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+static int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	struct irq_domain *domain;
+
+	domain = dev_get_msi_domain(&dev->dev);
+	if (domain && irq_domain_is_hierarchy(domain))
+		return msi_domain_alloc_irqs(domain, &dev->dev, nvec);
+
+	return arch_setup_msi_irqs(dev, nvec, type);
+}
+
+static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
+{
+	struct irq_domain *domain;
+
+	domain = dev_get_msi_domain(&dev->dev);
+	if (domain && irq_domain_is_hierarchy(domain))
+		msi_domain_free_irqs(domain, &dev->dev);
+	else
+		arch_teardown_msi_irqs(dev);
+}
+#else
+#define pci_msi_setup_msi_irqs		arch_setup_msi_irqs
+#define pci_msi_teardown_msi_irqs	arch_teardown_msi_irqs
+#endif
+
+#ifdef CONFIG_PCI_MSI_ARCH_FALLBACKS
+/* Arch hooks */
+int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
+{
+	struct msi_controller *chip = dev->bus->msi;
+	int err;
+
+	if (!chip || !chip->setup_irq)
+		return -EINVAL;
+
+	err = chip->setup_irq(chip, dev, desc);
+	if (err < 0)
+		return err;
+
+	irq_set_chip_data(desc->irq, chip);
+
+	return 0;
+}
+
+void __weak arch_teardown_msi_irq(unsigned int irq)
+{
+	struct msi_controller *chip = irq_get_chip_data(irq);
+
+	if (!chip || !chip->teardown_irq)
+		return;
+
+	chip->teardown_irq(chip, irq);
+}
+
+int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	struct msi_controller *chip = dev->bus->msi;
+	struct msi_desc *entry;
+	int ret;
+
+	if (chip && chip->setup_irqs)
+		return chip->setup_irqs(chip, dev, nvec, type);
+	/*
+	 * If an architecture wants to support multiple MSI, it needs to
+	 * override arch_setup_msi_irqs()
+	 */
+	if (type == PCI_CAP_ID_MSI && nvec > 1)
+		return 1;
+
+	for_each_pci_msi_entry(entry, dev) {
+		ret = arch_setup_msi_irq(dev, entry);
+		if (ret < 0)
+			return ret;
+		if (ret > 0)
+			return -ENOSPC;
+	}
+
+	return 0;
+}
+
+/*
+ * We have a default implementation available as a separate non-weak
+ * function, as it is used by the Xen x86 PCI code
+ */
+void default_teardown_msi_irqs(struct pci_dev *dev)
+{
+	int i;
+	struct msi_desc *entry;
+
+	for_each_pci_msi_entry(entry, dev)
+		if (entry->irq)
+			for (i = 0; i < entry->nvec_used; i++)
+				arch_teardown_msi_irq(entry->irq + i);
+}
+
+void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
+{
+	return default_teardown_msi_irqs(dev);
+}
+#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */
+
+static void default_restore_msi_irq(struct pci_dev *dev, int irq)
+{
+	struct msi_desc *entry;
+
+	entry = NULL;
+	if (dev->msix_enabled) {
+		for_each_pci_msi_entry(entry, dev) {
+			if (irq == entry->irq)
+				break;
+		}
+	} else if (dev->msi_enabled)  {
+		entry = irq_get_msi_desc(irq);
+	}
+
+	if (entry)
+		__pci_write_msi_msg(entry, &entry->msg);
+}
+
+void __weak arch_restore_msi_irqs(struct pci_dev *dev)
+{
+	return default_restore_msi_irqs(dev);
+}
+
+static inline __attribute_const__ u32 msi_mask(unsigned x)
+{
+	/* Don't shift by >= width of type */
+	if (x >= 5)
+		return 0xffffffff;
+	return (1 << (1 << x)) - 1;
+}
+
+/*
+ * PCI 2.3 does not specify mask bits for each MSI interrupt.  Attempting to
+ * mask all MSI interrupts by clearing the MSI enable bit does not work
+ * reliably as devices without an INTx disable bit will then generate a
+ * level IRQ which will never be cleared.
+ */
+void __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
+{
+	raw_spinlock_t *lock = &desc->dev->msi_lock;
+	unsigned long flags;
+
+	if (pci_msi_ignore_mask || !desc->msi_attrib.maskbit)
+		return;
+
+	raw_spin_lock_irqsave(lock, flags);
+	desc->masked &= ~mask;
+	desc->masked |= flag;
+	pci_write_config_dword(msi_desc_to_pci_dev(desc), desc->mask_pos,
+			       desc->masked);
+	raw_spin_unlock_irqrestore(lock, flags);
+}
+
+static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
+{
+	__pci_msi_desc_mask_irq(desc, mask, flag);
+}
+
+static void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
+{
+	if (desc->msi_attrib.is_virtual)
+		return NULL;
+
+	return desc->mask_base +
+		desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
+}
+
+/*
+ * This internal function does not flush PCI writes to the device.
+ * All users must ensure that they read from the device before either
+ * assuming that the device state is up to date, or returning out of this
+ * file.  This saves a few milliseconds when initialising devices with lots
+ * of MSI-X interrupts.
+ */
+u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
+{
+	u32 mask_bits = desc->masked;
+	void __iomem *desc_addr;
+
+	if (pci_msi_ignore_mask)
+		return 0;
+
+	desc_addr = pci_msix_desc_addr(desc);
+	if (!desc_addr)
+		return 0;
+
+	mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
+	if (flag & PCI_MSIX_ENTRY_CTRL_MASKBIT)
+		mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
+
+	writel(mask_bits, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
+
+	return mask_bits;
+}
+
+static void msix_mask_irq(struct msi_desc *desc, u32 flag)
+{
+	desc->masked = __pci_msix_desc_mask_irq(desc, flag);
+}
+
+static void msi_set_mask_bit(struct irq_data *data, u32 flag)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+	if (desc->msi_attrib.is_msix) {
+		msix_mask_irq(desc, flag);
+		readl(desc->mask_base);		/* Flush write to device */
+	} else {
+		unsigned offset = data->irq - desc->irq;
+		msi_mask_irq(desc, 1 << offset, flag << offset);
+	}
+}
+
+/**
+ * pci_msi_mask_irq - Generic IRQ chip callback to mask PCI/MSI interrupts
+ * @data:	pointer to irqdata associated to that interrupt
+ */
+void pci_msi_mask_irq(struct irq_data *data)
+{
+	msi_set_mask_bit(data, 1);
+}
+EXPORT_SYMBOL_GPL(pci_msi_mask_irq);
+
+/**
+ * pci_msi_unmask_irq - Generic IRQ chip callback to unmask PCI/MSI interrupts
+ * @data:	pointer to irqdata associated to that interrupt
+ */
+void pci_msi_unmask_irq(struct irq_data *data)
+{
+	msi_set_mask_bit(data, 0);
+}
+EXPORT_SYMBOL_GPL(pci_msi_unmask_irq);
+
+void default_restore_msi_irqs(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+
+	for_each_pci_msi_entry(entry, dev)
+		default_restore_msi_irq(dev, entry->irq);
+}
+
+void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
+{
+	struct pci_dev *dev = msi_desc_to_pci_dev(entry);
+
+	BUG_ON(dev->current_state != PCI_D0);
+
+	if (entry->msi_attrib.is_msix) {
+		void __iomem *base = pci_msix_desc_addr(entry);
+
+		if (!base) {
+			WARN_ON(1);
+			return;
+		}
+
+		msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
+		msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
+		msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
+	} else {
+		int pos = dev->msi_cap;
+		u16 data;
+
+		pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
+				      &msg->address_lo);
+		if (entry->msi_attrib.is_64) {
+			pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
+					      &msg->address_hi);
+			pci_read_config_word(dev, pos + PCI_MSI_DATA_64, &data);
+		} else {
+			msg->address_hi = 0;
+			pci_read_config_word(dev, pos + PCI_MSI_DATA_32, &data);
+		}
+		msg->data = data;
+	}
+}
+
+void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
+{
+	struct pci_dev *dev = msi_desc_to_pci_dev(entry);
+
+	if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) {
+		/* Don't touch the hardware now */
+	} else if (entry->msi_attrib.is_msix) {
+		void __iomem *base = pci_msix_desc_addr(entry);
+		bool unmasked = !(entry->masked & PCI_MSIX_ENTRY_CTRL_MASKBIT);
+
+		if (!base)
+			goto skip;
+
+		/*
+		 * The specification mandates that the entry is masked
+		 * when the message is modified:
+		 *
+		 * "If software changes the Address or Data value of an
+		 * entry while the entry is unmasked, the result is
+		 * undefined."
+		 */
+		if (unmasked)
+			__pci_msix_desc_mask_irq(entry, PCI_MSIX_ENTRY_CTRL_MASKBIT);
+
+		writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
+		writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
+		writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
+
+		if (unmasked)
+			__pci_msix_desc_mask_irq(entry, 0);
+
+		/* Ensure that the writes are visible in the device */
+		readl(base + PCI_MSIX_ENTRY_DATA);
+	} else {
+		int pos = dev->msi_cap;
+		u16 msgctl;
+
+		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+		msgctl &= ~PCI_MSI_FLAGS_QSIZE;
+		msgctl |= entry->msi_attrib.multiple << 4;
+		pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
+
+		pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
+				       msg->address_lo);
+		if (entry->msi_attrib.is_64) {
+			pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
+					       msg->address_hi);
+			pci_write_config_word(dev, pos + PCI_MSI_DATA_64,
+					      msg->data);
+		} else {
+			pci_write_config_word(dev, pos + PCI_MSI_DATA_32,
+					      msg->data);
+		}
+		/* Ensure that the writes are visible in the device */
+		pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+	}
+
+skip:
+	entry->msg = *msg;
+
+	if (entry->write_msi_msg)
+		entry->write_msi_msg(entry, entry->write_msi_msg_data);
+
+}
+
+void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)
+{
+	struct msi_desc *entry = irq_get_msi_desc(irq);
+
+	__pci_write_msi_msg(entry, msg);
+}
+EXPORT_SYMBOL_GPL(pci_write_msi_msg);
+
+static void free_msi_irqs(struct pci_dev *dev)
+{
+	struct list_head *msi_list = dev_to_msi_list(&dev->dev);
+	struct msi_desc *entry, *tmp;
+	struct attribute **msi_attrs;
+	struct device_attribute *dev_attr;
+	int i, count = 0;
+
+	for_each_pci_msi_entry(entry, dev)
+		if (entry->irq)
+			for (i = 0; i < entry->nvec_used; i++)
+				BUG_ON(irq_has_action(entry->irq + i));
+
+	if (dev->msi_irq_groups) {
+		sysfs_remove_groups(&dev->dev.kobj, dev->msi_irq_groups);
+		msi_attrs = dev->msi_irq_groups[0]->attrs;
+		while (msi_attrs[count]) {
+			dev_attr = container_of(msi_attrs[count],
+						struct device_attribute, attr);
+			kfree(dev_attr->attr.name);
+			kfree(dev_attr);
+			++count;
+		}
+		kfree(msi_attrs);
+		kfree(dev->msi_irq_groups[0]);
+		kfree(dev->msi_irq_groups);
+		dev->msi_irq_groups = NULL;
+	}
+
+	pci_msi_teardown_msi_irqs(dev);
+
+	list_for_each_entry_safe(entry, tmp, msi_list, list) {
+		if (entry->msi_attrib.is_msix) {
+			if (list_is_last(&entry->list, msi_list))
+				iounmap(entry->mask_base);
+		}
+
+		list_del(&entry->list);
+		free_msi_entry(entry);
+	}
+}
+
+static void pci_intx_for_msi(struct pci_dev *dev, int enable)
+{
+	if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG))
+		pci_intx(dev, enable);
+}
+
+static void __pci_restore_msi_state(struct pci_dev *dev)
+{
+	u16 control;
+	struct msi_desc *entry;
+
+	if (!dev->msi_enabled)
+		return;
+
+	entry = irq_get_msi_desc(dev->irq);
+
+	pci_intx_for_msi(dev, 0);
+	pci_msi_set_enable(dev, 0);
+	arch_restore_msi_irqs(dev);
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
+	msi_mask_irq(entry, msi_mask(entry->msi_attrib.multi_cap),
+		     entry->masked);
+	control &= ~PCI_MSI_FLAGS_QSIZE;
+	control |= (entry->msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
+	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
+}
+
+static void __pci_restore_msix_state(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+
+	if (!dev->msix_enabled)
+		return;
+	BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
+
+	/* route the table */
+	pci_intx_for_msi(dev, 0);
+	pci_msix_clear_and_set_ctrl(dev, 0,
+				PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL);
+
+	arch_restore_msi_irqs(dev);
+	for_each_pci_msi_entry(entry, dev)
+		msix_mask_irq(entry, entry->masked);
+
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
+}
+
+void pci_restore_msi_state(struct pci_dev *dev)
+{
+	__pci_restore_msi_state(dev);
+	__pci_restore_msix_state(dev);
+}
+EXPORT_SYMBOL_GPL(pci_restore_msi_state);
+
+static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct msi_desc *entry;
+	unsigned long irq;
+	int retval;
+
+	retval = kstrtoul(attr->attr.name, 10, &irq);
+	if (retval)
+		return retval;
+
+	entry = irq_get_msi_desc(irq);
+	if (entry)
+		return sprintf(buf, "%s\n",
+				entry->msi_attrib.is_msix ? "msix" : "msi");
+
+	return -ENODEV;
+}
+
+static int populate_msi_sysfs(struct pci_dev *pdev)
+{
+	struct attribute **msi_attrs;
+	struct attribute *msi_attr;
+	struct device_attribute *msi_dev_attr;
+	struct attribute_group *msi_irq_group;
+	const struct attribute_group **msi_irq_groups;
+	struct msi_desc *entry;
+	int ret = -ENOMEM;
+	int num_msi = 0;
+	int count = 0;
+	int i;
+
+	/* Determine how many msi entries we have */
+	for_each_pci_msi_entry(entry, pdev)
+		num_msi += entry->nvec_used;
+	if (!num_msi)
+		return 0;
+
+	/* Dynamically create the MSI attributes for the PCI device */
+	msi_attrs = kcalloc(num_msi + 1, sizeof(void *), GFP_KERNEL);
+	if (!msi_attrs)
+		return -ENOMEM;
+	for_each_pci_msi_entry(entry, pdev) {
+		for (i = 0; i < entry->nvec_used; i++) {
+			msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL);
+			if (!msi_dev_attr)
+				goto error_attrs;
+			msi_attrs[count] = &msi_dev_attr->attr;
+
+			sysfs_attr_init(&msi_dev_attr->attr);
+			msi_dev_attr->attr.name = kasprintf(GFP_KERNEL, "%d",
+							    entry->irq + i);
+			if (!msi_dev_attr->attr.name)
+				goto error_attrs;
+			msi_dev_attr->attr.mode = S_IRUGO;
+			msi_dev_attr->show = msi_mode_show;
+			++count;
+		}
+	}
+
+	msi_irq_group = kzalloc(sizeof(*msi_irq_group), GFP_KERNEL);
+	if (!msi_irq_group)
+		goto error_attrs;
+	msi_irq_group->name = "msi_irqs";
+	msi_irq_group->attrs = msi_attrs;
+
+	msi_irq_groups = kcalloc(2, sizeof(void *), GFP_KERNEL);
+	if (!msi_irq_groups)
+		goto error_irq_group;
+	msi_irq_groups[0] = msi_irq_group;
+
+	ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups);
+	if (ret)
+		goto error_irq_groups;
+	pdev->msi_irq_groups = msi_irq_groups;
+
+	return 0;
+
+error_irq_groups:
+	kfree(msi_irq_groups);
+error_irq_group:
+	kfree(msi_irq_group);
+error_attrs:
+	count = 0;
+	msi_attr = msi_attrs[count];
+	while (msi_attr) {
+		msi_dev_attr = container_of(msi_attr, struct device_attribute, attr);
+		kfree(msi_attr->name);
+		kfree(msi_dev_attr);
+		++count;
+		msi_attr = msi_attrs[count];
+	}
+	kfree(msi_attrs);
+	return ret;
+}
+
+static struct msi_desc *
+msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
+{
+	struct irq_affinity_desc *masks = NULL;
+	struct msi_desc *entry;
+	u16 control;
+
+	if (affd)
+		masks = irq_create_affinity_masks(nvec, affd);
+
+	/* MSI Entry Initialization */
+	entry = alloc_msi_entry(&dev->dev, nvec, masks);
+	if (!entry)
+		goto out;
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
+	/* Lies, damned lies, and MSIs */
+	if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING)
+		control |= PCI_MSI_FLAGS_MASKBIT;
+
+	entry->msi_attrib.is_msix	= 0;
+	entry->msi_attrib.is_64		= !!(control & PCI_MSI_FLAGS_64BIT);
+	entry->msi_attrib.is_virtual    = 0;
+	entry->msi_attrib.entry_nr	= 0;
+	entry->msi_attrib.maskbit	= !!(control & PCI_MSI_FLAGS_MASKBIT);
+	entry->msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
+	entry->msi_attrib.multi_cap	= (control & PCI_MSI_FLAGS_QMASK) >> 1;
+	entry->msi_attrib.multiple	= ilog2(__roundup_pow_of_two(nvec));
+
+	if (control & PCI_MSI_FLAGS_64BIT)
+		entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
+	else
+		entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
+
+	/* Save the initial mask status */
+	if (entry->msi_attrib.maskbit)
+		pci_read_config_dword(dev, entry->mask_pos, &entry->masked);
+
+out:
+	kfree(masks);
+	return entry;
+}
+
+static int msi_verify_entries(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+
+	for_each_pci_msi_entry(entry, dev) {
+		if (!dev->no_64bit_msi || !entry->msg.address_hi)
+			continue;
+		pci_err(dev, "Device has broken 64-bit MSI but arch"
+			" tried to assign one above 4G\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+/**
+ * msi_capability_init - configure device's MSI capability structure
+ * @dev: pointer to the pci_dev data structure of MSI device function
+ * @nvec: number of interrupts to allocate
+ * @affd: description of automatic IRQ affinity assignments (may be %NULL)
+ *
+ * Setup the MSI capability structure of the device with the requested
+ * number of interrupts.  A return value of zero indicates the successful
+ * setup of an entry with the new MSI IRQ.  A negative return value indicates
+ * an error, and a positive return value indicates the number of interrupts
+ * which could have been allocated.
+ */
+static int msi_capability_init(struct pci_dev *dev, int nvec,
+			       struct irq_affinity *affd)
+{
+	struct msi_desc *entry;
+	int ret;
+	unsigned mask;
+
+	pci_msi_set_enable(dev, 0);	/* Disable MSI during set up */
+
+	entry = msi_setup_entry(dev, nvec, affd);
+	if (!entry)
+		return -ENOMEM;
+
+	/* All MSIs are unmasked by default; mask them all */
+	mask = msi_mask(entry->msi_attrib.multi_cap);
+	msi_mask_irq(entry, mask, mask);
+
+	list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
+
+	/* Configure MSI capability structure */
+	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
+	if (ret) {
+		msi_mask_irq(entry, mask, 0);
+		free_msi_irqs(dev);
+		return ret;
+	}
+
+	ret = msi_verify_entries(dev);
+	if (ret) {
+		msi_mask_irq(entry, mask, 0);
+		free_msi_irqs(dev);
+		return ret;
+	}
+
+	ret = populate_msi_sysfs(dev);
+	if (ret) {
+		msi_mask_irq(entry, mask, 0);
+		free_msi_irqs(dev);
+		return ret;
+	}
+
+	/* Set MSI enabled bits	*/
+	pci_intx_for_msi(dev, 0);
+	pci_msi_set_enable(dev, 1);
+	dev->msi_enabled = 1;
+
+	pcibios_free_irq(dev);
+	dev->irq = entry->irq;
+	return 0;
+}
+
+static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
+{
+	resource_size_t phys_addr;
+	u32 table_offset;
+	unsigned long flags;
+	u8 bir;
+
+	pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
+			      &table_offset);
+	bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
+	flags = pci_resource_flags(dev, bir);
+	if (!flags || (flags & IORESOURCE_UNSET))
+		return NULL;
+
+	table_offset &= PCI_MSIX_TABLE_OFFSET;
+	phys_addr = pci_resource_start(dev, bir) + table_offset;
+
+	return ioremap(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
+}
+
+static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
+			      struct msix_entry *entries, int nvec,
+			      struct irq_affinity *affd)
+{
+	struct irq_affinity_desc *curmsk, *masks = NULL;
+	struct msi_desc *entry;
+	void __iomem *addr;
+	int ret, i;
+	int vec_count = pci_msix_vec_count(dev);
+
+	if (affd)
+		masks = irq_create_affinity_masks(nvec, affd);
+
+	for (i = 0, curmsk = masks; i < nvec; i++) {
+		entry = alloc_msi_entry(&dev->dev, 1, curmsk);
+		if (!entry) {
+			if (!i)
+				iounmap(base);
+			else
+				free_msi_irqs(dev);
+			/* No enough memory. Don't try again */
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		entry->msi_attrib.is_msix	= 1;
+		entry->msi_attrib.is_64		= 1;
+
+		if (entries)
+			entry->msi_attrib.entry_nr = entries[i].entry;
+		else
+			entry->msi_attrib.entry_nr = i;
+
+		entry->msi_attrib.is_virtual =
+			entry->msi_attrib.entry_nr >= vec_count;
+
+		entry->msi_attrib.default_irq	= dev->irq;
+		entry->mask_base		= base;
+
+		addr = pci_msix_desc_addr(entry);
+		if (addr)
+			entry->masked = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
+
+		list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
+		if (masks)
+			curmsk++;
+	}
+	ret = 0;
+out:
+	kfree(masks);
+	return ret;
+}
+
+static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries)
+{
+	struct msi_desc *entry;
+
+	for_each_pci_msi_entry(entry, dev) {
+		if (entries) {
+			entries->vector = entry->irq;
+			entries++;
+		}
+	}
+}
+
+static void msix_mask_all(void __iomem *base, int tsize)
+{
+	u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT;
+	int i;
+
+	if (pci_msi_ignore_mask)
+		return;
+
+	for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE)
+		writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
+}
+
+/**
+ * msix_capability_init - configure device's MSI-X capability
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * @entries: pointer to an array of struct msix_entry entries
+ * @nvec: number of @entries
+ * @affd: Optional pointer to enable automatic affinity assignment
+ *
+ * Setup the MSI-X capability structure of device function with a
+ * single MSI-X IRQ. A return of zero indicates the successful setup of
+ * requested MSI-X entries with allocated IRQs or non-zero for otherwise.
+ **/
+static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
+				int nvec, struct irq_affinity *affd)
+{
+	void __iomem *base;
+	int ret, tsize;
+	u16 control;
+
+	/*
+	 * Some devices require MSI-X to be enabled before the MSI-X
+	 * registers can be accessed.  Mask all the vectors to prevent
+	 * interrupts coming in before they're fully set up.
+	 */
+	pci_msix_clear_and_set_ctrl(dev, 0, PCI_MSIX_FLAGS_MASKALL |
+				    PCI_MSIX_FLAGS_ENABLE);
+
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
+	/* Request & Map MSI-X table region */
+	tsize = msix_table_size(control);
+	base = msix_map_region(dev, tsize);
+	if (!base) {
+		ret = -ENOMEM;
+		goto out_disable;
+	}
+
+	ret = msix_setup_entries(dev, base, entries, nvec, affd);
+	if (ret)
+		goto out_disable;
+
+	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
+	if (ret)
+		goto out_avail;
+
+	/* Check if all MSI entries honor device restrictions */
+	ret = msi_verify_entries(dev);
+	if (ret)
+		goto out_free;
+
+	msix_update_entries(dev, entries);
+
+	ret = populate_msi_sysfs(dev);
+	if (ret)
+		goto out_free;
+
+	/* Set MSI-X enabled bits and unmask the function */
+	pci_intx_for_msi(dev, 0);
+	dev->msix_enabled = 1;
+
+	/*
+	 * Ensure that all table entries are masked to prevent
+	 * stale entries from firing in a crash kernel.
+	 *
+	 * Done late to deal with a broken Marvell NVME device
+	 * which takes the MSI-X mask bits into account even
+	 * when MSI-X is disabled, which prevents MSI delivery.
+	 */
+	msix_mask_all(base, tsize);
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
+
+	pcibios_free_irq(dev);
+	return 0;
+
+out_avail:
+	if (ret < 0) {
+		/*
+		 * If we had some success, report the number of IRQs
+		 * we succeeded in setting up.
+		 */
+		struct msi_desc *entry;
+		int avail = 0;
+
+		for_each_pci_msi_entry(entry, dev) {
+			if (entry->irq != 0)
+				avail++;
+		}
+		if (avail != 0)
+			ret = avail;
+	}
+
+out_free:
+	free_msi_irqs(dev);
+
+out_disable:
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0);
+
+	return ret;
+}
+
+/**
+ * pci_msi_supported - check whether MSI may be enabled on a device
+ * @dev: pointer to the pci_dev data structure of MSI device function
+ * @nvec: how many MSIs have been requested?
+ *
+ * Look at global flags, the device itself, and its parent buses
+ * to determine if MSI/-X are supported for the device. If MSI/-X is
+ * supported return 1, else return 0.
+ **/
+static int pci_msi_supported(struct pci_dev *dev, int nvec)
+{
+	struct pci_bus *bus;
+
+	/* MSI must be globally enabled and supported by the device */
+	if (!pci_msi_enable)
+		return 0;
+
+	if (!dev || dev->no_msi)
+		return 0;
+
+	/*
+	 * You can't ask to have 0 or less MSIs configured.
+	 *  a) it's stupid ..
+	 *  b) the list manipulation code assumes nvec >= 1.
+	 */
+	if (nvec < 1)
+		return 0;
+
+	/*
+	 * Any bridge which does NOT route MSI transactions from its
+	 * secondary bus to its primary bus must set NO_MSI flag on
+	 * the secondary pci_bus.
+	 * We expect only arch-specific PCI host bus controller driver
+	 * or quirks for specific PCI bridges to be setting NO_MSI.
+	 */
+	for (bus = dev->bus; bus; bus = bus->parent)
+		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
+			return 0;
+
+	return 1;
+}
+
+/**
+ * pci_msi_vec_count - Return the number of MSI vectors a device can send
+ * @dev: device to report about
+ *
+ * This function returns the number of MSI vectors a device requested via
+ * Multiple Message Capable register. It returns a negative errno if the
+ * device is not capable sending MSI interrupts. Otherwise, the call succeeds
+ * and returns a power of two, up to a maximum of 2^5 (32), according to the
+ * MSI specification.
+ **/
+int pci_msi_vec_count(struct pci_dev *dev)
+{
+	int ret;
+	u16 msgctl;
+
+	if (!dev->msi_cap)
+		return -EINVAL;
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
+	ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
+
+	return ret;
+}
+EXPORT_SYMBOL(pci_msi_vec_count);
+
+static void pci_msi_shutdown(struct pci_dev *dev)
+{
+	struct msi_desc *desc;
+	u32 mask;
+
+	if (!pci_msi_enable || !dev || !dev->msi_enabled)
+		return;
+
+	BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
+	desc = first_pci_msi_entry(dev);
+
+	pci_msi_set_enable(dev, 0);
+	pci_intx_for_msi(dev, 1);
+	dev->msi_enabled = 0;
+
+	/* Return the device with MSI unmasked as initial states */
+	mask = msi_mask(desc->msi_attrib.multi_cap);
+	msi_mask_irq(desc, mask, 0);
+
+	/* Restore dev->irq to its default pin-assertion IRQ */
+	dev->irq = desc->msi_attrib.default_irq;
+	pcibios_alloc_irq(dev);
+}
+
+void pci_disable_msi(struct pci_dev *dev)
+{
+	if (!pci_msi_enable || !dev || !dev->msi_enabled)
+		return;
+
+	pci_msi_shutdown(dev);
+	free_msi_irqs(dev);
+}
+EXPORT_SYMBOL(pci_disable_msi);
+
+/**
+ * pci_msix_vec_count - return the number of device's MSI-X table entries
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * This function returns the number of device's MSI-X table entries and
+ * therefore the number of MSI-X vectors device is capable of sending.
+ * It returns a negative errno if the device is not capable of sending MSI-X
+ * interrupts.
+ **/
+int pci_msix_vec_count(struct pci_dev *dev)
+{
+	u16 control;
+
+	if (!dev->msix_cap)
+		return -EINVAL;
+
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
+	return msix_table_size(control);
+}
+EXPORT_SYMBOL(pci_msix_vec_count);
+
+static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
+			     int nvec, struct irq_affinity *affd, int flags)
+{
+	int nr_entries;
+	int i, j;
+
+	if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
+		return -EINVAL;
+
+	nr_entries = pci_msix_vec_count(dev);
+	if (nr_entries < 0)
+		return nr_entries;
+	if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL))
+		return nr_entries;
+
+	if (entries) {
+		/* Check for any invalid entries */
+		for (i = 0; i < nvec; i++) {
+			if (entries[i].entry >= nr_entries)
+				return -EINVAL;		/* invalid entry */
+			for (j = i + 1; j < nvec; j++) {
+				if (entries[i].entry == entries[j].entry)
+					return -EINVAL;	/* duplicate entry */
+			}
+		}
+	}
+
+	/* Check whether driver already requested for MSI IRQ */
+	if (dev->msi_enabled) {
+		pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
+		return -EINVAL;
+	}
+	return msix_capability_init(dev, entries, nvec, affd);
+}
+
+static void pci_msix_shutdown(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+
+	if (!pci_msi_enable || !dev || !dev->msix_enabled)
+		return;
+
+	if (pci_dev_is_disconnected(dev)) {
+		dev->msix_enabled = 0;
+		return;
+	}
+
+	/* Return the device with MSI-X masked as initial states */
+	for_each_pci_msi_entry(entry, dev)
+		__pci_msix_desc_mask_irq(entry, 1);
+
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
+	pci_intx_for_msi(dev, 1);
+	dev->msix_enabled = 0;
+	pcibios_alloc_irq(dev);
+}
+
+void pci_disable_msix(struct pci_dev *dev)
+{
+	if (!pci_msi_enable || !dev || !dev->msix_enabled)
+		return;
+
+	pci_msix_shutdown(dev);
+	free_msi_irqs(dev);
+}
+EXPORT_SYMBOL(pci_disable_msix);
+
+void pci_no_msi(void)
+{
+	pci_msi_enable = 0;
+}
+
+/**
+ * pci_msi_enabled - is MSI enabled?
+ *
+ * Returns true if MSI has not been disabled by the command-line option
+ * pci=nomsi.
+ **/
+int pci_msi_enabled(void)
+{
+	return pci_msi_enable;
+}
+EXPORT_SYMBOL(pci_msi_enabled);
+
+static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
+				  struct irq_affinity *affd)
+{
+	int nvec;
+	int rc;
+
+	if (!pci_msi_supported(dev, minvec) || dev->current_state != PCI_D0)
+		return -EINVAL;
+
+	/* Check whether driver already requested MSI-X IRQs */
+	if (dev->msix_enabled) {
+		pci_info(dev, "can't enable MSI (MSI-X already enabled)\n");
+		return -EINVAL;
+	}
+
+	if (maxvec < minvec)
+		return -ERANGE;
+
+	if (WARN_ON_ONCE(dev->msi_enabled))
+		return -EINVAL;
+
+	nvec = pci_msi_vec_count(dev);
+	if (nvec < 0)
+		return nvec;
+	if (nvec < minvec)
+		return -ENOSPC;
+
+	if (nvec > maxvec)
+		nvec = maxvec;
+
+	for (;;) {
+		if (affd) {
+			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
+			if (nvec < minvec)
+				return -ENOSPC;
+		}
+
+		rc = msi_capability_init(dev, nvec, affd);
+		if (rc == 0)
+			return nvec;
+
+		if (rc < 0)
+			return rc;
+		if (rc < minvec)
+			return -ENOSPC;
+
+		nvec = rc;
+	}
+}
+
+/* deprecated, don't use */
+int pci_enable_msi(struct pci_dev *dev)
+{
+	int rc = __pci_enable_msi_range(dev, 1, 1, NULL);
+	if (rc < 0)
+		return rc;
+	return 0;
+}
+EXPORT_SYMBOL(pci_enable_msi);
+
+static int __pci_enable_msix_range(struct pci_dev *dev,
+				   struct msix_entry *entries, int minvec,
+				   int maxvec, struct irq_affinity *affd,
+				   int flags)
+{
+	int rc, nvec = maxvec;
+
+	if (maxvec < minvec)
+		return -ERANGE;
+
+	if (WARN_ON_ONCE(dev->msix_enabled))
+		return -EINVAL;
+
+	for (;;) {
+		if (affd) {
+			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
+			if (nvec < minvec)
+				return -ENOSPC;
+		}
+
+		rc = __pci_enable_msix(dev, entries, nvec, affd, flags);
+		if (rc == 0)
+			return nvec;
+
+		if (rc < 0)
+			return rc;
+		if (rc < minvec)
+			return -ENOSPC;
+
+		nvec = rc;
+	}
+}
+
+/**
+ * pci_enable_msix_range - configure device's MSI-X capability structure
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * @entries: pointer to an array of MSI-X entries
+ * @minvec: minimum number of MSI-X IRQs requested
+ * @maxvec: maximum number of MSI-X IRQs requested
+ *
+ * Setup the MSI-X capability structure of device function with a maximum
+ * possible number of interrupts in the range between @minvec and @maxvec
+ * upon its software driver call to request for MSI-X mode enabled on its
+ * hardware device function. It returns a negative errno if an error occurs.
+ * If it succeeds, it returns the actual number of interrupts allocated and
+ * indicates the successful configuration of MSI-X capability structure
+ * with new allocated MSI-X interrupts.
+ **/
+int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
+		int minvec, int maxvec)
+{
+	return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0);
+}
+EXPORT_SYMBOL(pci_enable_msix_range);
+
+/**
+ * pci_alloc_irq_vectors_affinity - allocate multiple IRQs for a device
+ * @dev:		PCI device to operate on
+ * @min_vecs:		minimum number of vectors required (must be >= 1)
+ * @max_vecs:		maximum (desired) number of vectors
+ * @flags:		flags or quirks for the allocation
+ * @affd:		optional description of the affinity requirements
+ *
+ * Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X or MSI
+ * vectors if available, and fall back to a single legacy vector
+ * if neither is available.  Return the number of vectors allocated,
+ * (which might be smaller than @max_vecs) if successful, or a negative
+ * error code on error. If less than @min_vecs interrupt vectors are
+ * available for @dev the function will fail with -ENOSPC.
+ *
+ * To get the Linux IRQ number used for a vector that can be passed to
+ * request_irq() use the pci_irq_vector() helper.
+ */
+int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
+				   unsigned int max_vecs, unsigned int flags,
+				   struct irq_affinity *affd)
+{
+	struct irq_affinity msi_default_affd = {0};
+	int nvecs = -ENOSPC;
+
+	if (flags & PCI_IRQ_AFFINITY) {
+		if (!affd)
+			affd = &msi_default_affd;
+	} else {
+		if (WARN_ON(affd))
+			affd = NULL;
+	}
+
+	if (flags & PCI_IRQ_MSIX) {
+		nvecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs,
+						affd, flags);
+		if (nvecs > 0)
+			return nvecs;
+	}
+
+	if (flags & PCI_IRQ_MSI) {
+		nvecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd);
+		if (nvecs > 0)
+			return nvecs;
+	}
+
+	/* use legacy IRQ if allowed */
+	if (flags & PCI_IRQ_LEGACY) {
+		if (min_vecs == 1 && dev->irq) {
+			/*
+			 * Invoke the affinity spreading logic to ensure that
+			 * the device driver can adjust queue configuration
+			 * for the single interrupt case.
+			 */
+			if (affd)
+				irq_create_affinity_masks(1, affd);
+			pci_intx(dev, 1);
+			return 1;
+		}
+	}
+
+	return nvecs;
+}
+EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);
+
+/**
+ * pci_free_irq_vectors - free previously allocated IRQs for a device
+ * @dev:		PCI device to operate on
+ *
+ * Undoes the allocations and enabling in pci_alloc_irq_vectors().
+ */
+void pci_free_irq_vectors(struct pci_dev *dev)
+{
+	pci_disable_msix(dev);
+	pci_disable_msi(dev);
+}
+EXPORT_SYMBOL(pci_free_irq_vectors);
+
+/**
+ * pci_irq_vector - return Linux IRQ number of a device vector
+ * @dev:	PCI device to operate on
+ * @nr:		Interrupt vector index (0-based)
+ *
+ * @nr has the following meanings depending on the interrupt mode:
+ *   MSI-X:	The index in the MSI-X vector table
+ *   MSI:	The index of the enabled MSI vectors
+ *   INTx:	Must be 0
+ *
+ * Return: The Linux interrupt number or -EINVAl if @nr is out of range.
+ */
+int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
+{
+	if (dev->msix_enabled) {
+		struct msi_desc *entry;
+
+		for_each_pci_msi_entry(entry, dev) {
+			if (entry->msi_attrib.entry_nr == nr)
+				return entry->irq;
+		}
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
+	if (dev->msi_enabled) {
+		struct msi_desc *entry = first_pci_msi_entry(dev);
+
+		if (WARN_ON_ONCE(nr >= entry->nvec_used))
+			return -EINVAL;
+	} else {
+		if (WARN_ON_ONCE(nr > 0))
+			return -EINVAL;
+	}
+
+	return dev->irq + nr;
+}
+EXPORT_SYMBOL(pci_irq_vector);
+
+/**
+ * pci_irq_get_affinity - return the affinity of a particular MSI vector
+ * @dev:	PCI device to operate on
+ * @nr:		device-relative interrupt vector index (0-based).
+ *
+ * @nr has the following meanings depending on the interrupt mode:
+ *   MSI-X:	The index in the MSI-X vector table
+ *   MSI:	The index of the enabled MSI vectors
+ *   INTx:	Must be 0
+ *
+ * Return: A cpumask pointer or NULL if @nr is out of range
+ */
+const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
+{
+	if (dev->msix_enabled) {
+		struct msi_desc *entry;
+
+		for_each_pci_msi_entry(entry, dev) {
+			if (entry->msi_attrib.entry_nr == nr)
+				return &entry->affinity->mask;
+		}
+		WARN_ON_ONCE(1);
+		return NULL;
+	} else if (dev->msi_enabled) {
+		struct msi_desc *entry = first_pci_msi_entry(dev);
+
+		if (WARN_ON_ONCE(!entry || !entry->affinity ||
+				 nr >= entry->nvec_used))
+			return NULL;
+
+		return &entry->affinity[nr].mask;
+	} else {
+		return cpu_possible_mask;
+	}
+}
+EXPORT_SYMBOL(pci_irq_get_affinity);
+
+struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
+{
+	return to_pci_dev(desc->dev);
+}
+EXPORT_SYMBOL(msi_desc_to_pci_dev);
+
+void *msi_desc_to_pci_sysdata(struct msi_desc *desc)
+{
+	struct pci_dev *dev = msi_desc_to_pci_dev(desc);
+
+	return dev->bus->sysdata;
+}
+EXPORT_SYMBOL_GPL(msi_desc_to_pci_sysdata);
+
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+/**
+ * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space
+ * @irq_data:	Pointer to interrupt data of the MSI interrupt
+ * @msg:	Pointer to the message
+ */
+void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(irq_data);
+
+	/*
+	 * For MSI-X desc->irq is always equal to irq_data->irq. For
+	 * MSI only the first interrupt of MULTI MSI passes the test.
+	 */
+	if (desc->irq == irq_data->irq)
+		__pci_write_msi_msg(desc, msg);
+}
+
+/**
+ * pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source
+ * @desc:	Pointer to the MSI descriptor
+ *
+ * The ID number is only used within the irqdomain.
+ */
+static irq_hw_number_t pci_msi_domain_calc_hwirq(struct msi_desc *desc)
+{
+	struct pci_dev *dev = msi_desc_to_pci_dev(desc);
+
+	return (irq_hw_number_t)desc->msi_attrib.entry_nr |
+		pci_dev_id(dev) << 11 |
+		(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
+}
+
+static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc)
+{
+	return !desc->msi_attrib.is_msix && desc->nvec_used > 1;
+}
+
+/**
+ * pci_msi_domain_check_cap - Verify that @domain supports the capabilities
+ * 			      for @dev
+ * @domain:	The interrupt domain to check
+ * @info:	The domain info for verification
+ * @dev:	The device to check
+ *
+ * Returns:
+ *  0 if the functionality is supported
+ *  1 if Multi MSI is requested, but the domain does not support it
+ *  -ENOTSUPP otherwise
+ */
+int pci_msi_domain_check_cap(struct irq_domain *domain,
+			     struct msi_domain_info *info, struct device *dev)
+{
+	struct msi_desc *desc = first_pci_msi_entry(to_pci_dev(dev));
+
+	/* Special handling to support __pci_enable_msi_range() */
+	if (pci_msi_desc_is_multi_msi(desc) &&
+	    !(info->flags & MSI_FLAG_MULTI_PCI_MSI))
+		return 1;
+	else if (desc->msi_attrib.is_msix && !(info->flags & MSI_FLAG_PCI_MSIX))
+		return -ENOTSUPP;
+
+	return 0;
+}
+
+static int pci_msi_domain_handle_error(struct irq_domain *domain,
+				       struct msi_desc *desc, int error)
+{
+	/* Special handling to support __pci_enable_msi_range() */
+	if (pci_msi_desc_is_multi_msi(desc) && error == -ENOSPC)
+		return 1;
+
+	return error;
+}
+
+static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,
+				    struct msi_desc *desc)
+{
+	arg->desc = desc;
+	arg->hwirq = pci_msi_domain_calc_hwirq(desc);
+}
+
+static struct msi_domain_ops pci_msi_domain_ops_default = {
+	.set_desc	= pci_msi_domain_set_desc,
+	.msi_check	= pci_msi_domain_check_cap,
+	.handle_error	= pci_msi_domain_handle_error,
+};
+
+static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info)
+{
+	struct msi_domain_ops *ops = info->ops;
+
+	if (ops == NULL) {
+		info->ops = &pci_msi_domain_ops_default;
+	} else {
+		if (ops->set_desc == NULL)
+			ops->set_desc = pci_msi_domain_set_desc;
+		if (ops->msi_check == NULL)
+			ops->msi_check = pci_msi_domain_check_cap;
+		if (ops->handle_error == NULL)
+			ops->handle_error = pci_msi_domain_handle_error;
+	}
+}
+
+static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info)
+{
+	struct irq_chip *chip = info->chip;
+
+	BUG_ON(!chip);
+	if (!chip->irq_write_msi_msg)
+		chip->irq_write_msi_msg = pci_msi_domain_write_msg;
+	if (!chip->irq_mask)
+		chip->irq_mask = pci_msi_mask_irq;
+	if (!chip->irq_unmask)
+		chip->irq_unmask = pci_msi_unmask_irq;
+}
+
+/**
+ * pci_msi_create_irq_domain - Create a MSI interrupt domain
+ * @fwnode:	Optional fwnode of the interrupt controller
+ * @info:	MSI domain info
+ * @parent:	Parent irq domain
+ *
+ * Updates the domain and chip ops and creates a MSI interrupt domain.
+ *
+ * Returns:
+ * A domain pointer or NULL in case of failure.
+ */
+struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
+					     struct msi_domain_info *info,
+					     struct irq_domain *parent)
+{
+	struct irq_domain *domain;
+
+	if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE))
+		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
+
+	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
+		pci_msi_domain_update_dom_ops(info);
+	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
+		pci_msi_domain_update_chip_ops(info);
+
+	info->flags |= MSI_FLAG_ACTIVATE_EARLY;
+	if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
+		info->flags |= MSI_FLAG_MUST_REACTIVATE;
+
+	/* PCI-MSI is oneshot-safe */
+	info->chip->flags |= IRQCHIP_ONESHOT_SAFE;
+
+	domain = msi_create_irq_domain(fwnode, info, parent);
+	if (!domain)
+		return NULL;
+
+	irq_domain_update_bus_token(domain, DOMAIN_BUS_PCI_MSI);
+	return domain;
+}
+EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain);
+
+/*
+ * Users of the generic MSI infrastructure expect a device to have a single ID,
+ * so with DMA aliases we have to pick the least-worst compromise. Devices with
+ * DMA phantom functions tend to still emit MSIs from the real function number,
+ * so we ignore those and only consider topological aliases where either the
+ * alias device or RID appears on a different bus number. We also make the
+ * reasonable assumption that bridges are walked in an upstream direction (so
+ * the last one seen wins), and the much braver assumption that the most likely
+ * case is that of PCI->PCIe so we should always use the alias RID. This echoes
+ * the logic from intel_irq_remapping's set_msi_sid(), which presumably works
+ * well enough in practice; in the face of the horrible PCIe<->PCI-X conditions
+ * for taking ownership all we can really do is close our eyes and hope...
+ */
+static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data)
+{
+	u32 *pa = data;
+	u8 bus = PCI_BUS_NUM(*pa);
+
+	if (pdev->bus->number != bus || PCI_BUS_NUM(alias) != bus)
+		*pa = alias;
+
+	return 0;
+}
+
+/**
+ * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID)
+ * @domain:	The interrupt domain
+ * @pdev:	The PCI device.
+ *
+ * The RID for a device is formed from the alias, with a firmware
+ * supplied mapping applied
+ *
+ * Returns: The RID.
+ */
+u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
+{
+	struct device_node *of_node;
+	u32 rid = pci_dev_id(pdev);
+
+	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+
+	of_node = irq_domain_get_of_node(domain);
+	rid = of_node ? of_msi_map_id(&pdev->dev, of_node, rid) :
+			iort_msi_map_id(&pdev->dev, rid);
+
+	return rid;
+}
+
+/**
+ * pci_msi_get_device_domain - Get the MSI domain for a given PCI device
+ * @pdev:	The PCI device
+ *
+ * Use the firmware data to find a device-specific MSI domain
+ * (i.e. not one that is set as a default).
+ *
+ * Returns: The corresponding MSI domain or NULL if none has been found.
+ */
+struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
+{
+	struct irq_domain *dom;
+	u32 rid = pci_dev_id(pdev);
+
+	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+	dom = of_msi_map_get_device_domain(&pdev->dev, rid, DOMAIN_BUS_PCI_MSI);
+	if (!dom)
+		dom = iort_get_device_domain(&pdev->dev, rid,
+					     DOMAIN_BUS_PCI_MSI);
+	return dom;
+}
+
+/**
+ * pci_dev_has_special_msi_domain - Check whether the device is handled by
+ *				    a non-standard PCI-MSI domain
+ * @pdev:	The PCI device to check.
+ *
+ * Returns: True if the device irqdomain or the bus irqdomain is
+ * non-standard PCI/MSI.
+ */
+bool pci_dev_has_special_msi_domain(struct pci_dev *pdev)
+{
+	struct irq_domain *dom = dev_get_msi_domain(&pdev->dev);
+
+	if (!dom)
+		dom = dev_get_msi_domain(&pdev->bus->dev);
+
+	if (!dom)
+		return true;
+
+	return dom->bus_token != DOMAIN_BUS_PCI_MSI;
+}
+
+#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */