Re: [patch V2 15/23] PCI/MSI: Move code into a separate directory

[Bjorn Helgaas]

On Mon, Dec 06, 2021 at 11:27:47PM +0100, Thomas Gleixner wrote:
> msi.c is getting larger and really could do with a splitup. Move it into
> it's own directory to prepare for that.

s/it's/its/

> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Tested-by: Juergen Gross <jgross@xxxxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

> ---
>  Documentation/driver-api/pci/pci.rst |    2 
>  drivers/pci/Makefile                 |    3 
>  drivers/pci/msi.c                    | 1532 -----------------------------------
>  drivers/pci/msi/Makefile             |    4 
>  drivers/pci/msi/msi.c                | 1532 +++++++++++++++++++++++++++++++++++
>  5 files changed, 1539 insertions(+), 1534 deletions(-)
> 
> --- a/Documentation/driver-api/pci/pci.rst
> +++ b/Documentation/driver-api/pci/pci.rst
> @@ -13,7 +13,7 @@ PCI Support Library
>  .. kernel-doc:: drivers/pci/search.c
>     :export:
>  
> -.. kernel-doc:: drivers/pci/msi.c
> +.. kernel-doc:: drivers/pci/msi/msi.c
>     :export:
>  
>  .. kernel-doc:: drivers/pci/bus.c
> --- a/drivers/pci/Makefile
> +++ b/drivers/pci/Makefile
> @@ -5,8 +5,9 @@
>  obj-$(CONFIG_PCI)		+= access.o bus.o probe.o host-bridge.o \
>  				   remove.o pci.o pci-driver.o search.o \
>  				   pci-sysfs.o rom.o setup-res.o irq.o vpd.o \
> -				   setup-bus.o vc.o mmap.o setup-irq.o msi.o
> +				   setup-bus.o vc.o mmap.o setup-irq.o
>  
> +obj-$(CONFIG_PCI)		+= msi/
>  obj-$(CONFIG_PCI)		+= pcie/
>  
>  ifdef CONFIG_PCI
> --- a/drivers/pci/msi.c
> +++ /dev/null
> @@ -1,1532 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/*
> - * PCI Message Signaled Interrupt (MSI)
> - *
> - * Copyright (C) 2003-2004 Intel
> - * Copyright (C) Tom Long Nguyen (tom.l.nguyen@xxxxxxxxx)
> - * Copyright (C) 2016 Christoph Hellwig.
> - */
> -
> -#include <linux/acpi_iort.h>
> -#include <linux/err.h>
> -#include <linux/export.h>
> -#include <linux/irq.h>
> -#include <linux/irqdomain.h>
> -#include <linux/msi.h>
> -#include <linux/of_irq.h>
> -#include <linux/pci.h>
> -
> -#include "pci.h"
> -
> -#ifdef CONFIG_PCI_MSI
> -
> -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)
> -{
> -	return -EINVAL;
> -}
> -
> -void __weak arch_teardown_msi_irq(unsigned int irq)
> -{
> -}
> -
> -int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
> -{
> -	struct msi_desc *entry;
> -	int ret;
> -
> -	/*
> -	 * 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;
> -}
> -
> -void __weak arch_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);
> -}
> -#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */
> -
> -/*
> - * 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.
> - */
> -static inline __attribute_const__ u32 msi_multi_mask(struct msi_desc *desc)
> -{
> -	/* Don't shift by >= width of type */
> -	if (desc->pci.msi_attrib.multi_cap >= 5)
> -		return 0xffffffff;
> -	return (1 << (1 << desc->pci.msi_attrib.multi_cap)) - 1;
> -}
> -
> -static noinline void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 set)
> -{
> -	raw_spinlock_t *lock = &desc->dev->msi_lock;
> -	unsigned long flags;
> -
> -	if (!desc->pci.msi_attrib.can_mask)
> -		return;
> -
> -	raw_spin_lock_irqsave(lock, flags);
> -	desc->pci.msi_mask &= ~clear;
> -	desc->pci.msi_mask |= set;
> -	pci_write_config_dword(msi_desc_to_pci_dev(desc), desc->pci.mask_pos,
> -			       desc->pci.msi_mask);
> -	raw_spin_unlock_irqrestore(lock, flags);
> -}
> -
> -static inline void pci_msi_mask(struct msi_desc *desc, u32 mask)
> -{
> -	pci_msi_update_mask(desc, 0, mask);
> -}
> -
> -static inline void pci_msi_unmask(struct msi_desc *desc, u32 mask)
> -{
> -	pci_msi_update_mask(desc, mask, 0);
> -}
> -
> -static inline void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
> -{
> -	return desc->pci.mask_base + desc->pci.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.
> - * It does not affect the msi_desc::msix_ctrl cache either. Use with care!
> - */
> -static void pci_msix_write_vector_ctrl(struct msi_desc *desc, u32 ctrl)
> -{
> -	void __iomem *desc_addr = pci_msix_desc_addr(desc);
> -
> -	if (desc->pci.msi_attrib.can_mask)
> -		writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
> -}
> -
> -static inline void pci_msix_mask(struct msi_desc *desc)
> -{
> -	desc->pci.msix_ctrl |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
> -	pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
> -	/* Flush write to device */
> -	readl(desc->pci.mask_base);
> -}
> -
> -static inline void pci_msix_unmask(struct msi_desc *desc)
> -{
> -	desc->pci.msix_ctrl &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
> -	pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
> -}
> -
> -static void __pci_msi_mask_desc(struct msi_desc *desc, u32 mask)
> -{
> -	if (desc->pci.msi_attrib.is_msix)
> -		pci_msix_mask(desc);
> -	else
> -		pci_msi_mask(desc, mask);
> -}
> -
> -static void __pci_msi_unmask_desc(struct msi_desc *desc, u32 mask)
> -{
> -	if (desc->pci.msi_attrib.is_msix)
> -		pci_msix_unmask(desc);
> -	else
> -		pci_msi_unmask(desc, mask);
> -}
> -
> -/**
> - * 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)
> -{
> -	struct msi_desc *desc = irq_data_get_msi_desc(data);
> -
> -	__pci_msi_mask_desc(desc, BIT(data->irq - desc->irq));
> -}
> -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)
> -{
> -	struct msi_desc *desc = irq_data_get_msi_desc(data);
> -
> -	__pci_msi_unmask_desc(desc, BIT(data->irq - desc->irq));
> -}
> -EXPORT_SYMBOL_GPL(pci_msi_unmask_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->pci.msi_attrib.is_msix) {
> -		void __iomem *base = pci_msix_desc_addr(entry);
> -
> -		if (WARN_ON_ONCE(entry->pci.msi_attrib.is_virtual))
> -			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->pci.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->pci.msi_attrib.is_msix) {
> -		void __iomem *base = pci_msix_desc_addr(entry);
> -		u32 ctrl = entry->pci.msix_ctrl;
> -		bool unmasked = !(ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
> -
> -		if (entry->pci.msi_attrib.is_virtual)
> -			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_write_vector_ctrl(entry, ctrl | 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_write_vector_ctrl(entry, ctrl);
> -
> -		/* 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->pci.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->pci.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;
> -	int i;
> -
> -	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) {
> -		msi_destroy_sysfs(&dev->dev, 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->pci.msi_attrib.is_msix) {
> -			if (list_is_last(&entry->list, msi_list))
> -				iounmap(entry->pci.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_msi_set_enable(struct pci_dev *dev, int enable)
> -{
> -	u16 control;
> -
> -	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
> -	control &= ~PCI_MSI_FLAGS_ENABLE;
> -	if (enable)
> -		control |= PCI_MSI_FLAGS_ENABLE;
> -	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
> -}
> -
> -/*
> - * Architecture override returns true when the PCI MSI message should be
> - * written by the generic restore function.
> - */
> -bool __weak arch_restore_msi_irqs(struct pci_dev *dev)
> -{
> -	return true;
> -}
> -
> -static void __pci_restore_msi_state(struct pci_dev *dev)
> -{
> -	struct msi_desc *entry;
> -	u16 control;
> -
> -	if (!dev->msi_enabled)
> -		return;
> -
> -	entry = irq_get_msi_desc(dev->irq);
> -
> -	pci_intx_for_msi(dev, 0);
> -	pci_msi_set_enable(dev, 0);
> -	if (arch_restore_msi_irqs(dev))
> -		__pci_write_msi_msg(entry, &entry->msg);
> -
> -	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
> -	pci_msi_update_mask(entry, 0, 0);
> -	control &= ~PCI_MSI_FLAGS_QSIZE;
> -	control |= (entry->pci.msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
> -	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
> -}
> -
> -static void pci_msix_clear_and_set_ctrl(struct pci_dev *dev, u16 clear, u16 set)
> -{
> -	u16 ctrl;
> -
> -	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
> -	ctrl &= ~clear;
> -	ctrl |= set;
> -	pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, ctrl);
> -}
> -
> -static void __pci_restore_msix_state(struct pci_dev *dev)
> -{
> -	struct msi_desc *entry;
> -	bool write_msg;
> -
> -	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);
> -
> -	write_msg = arch_restore_msi_irqs(dev);
> -
> -	for_each_pci_msi_entry(entry, dev) {
> -		if (write_msg)
> -			__pci_write_msi_msg(entry, &entry->msg);
> -		pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
> -	}
> -
> -	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 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->pci.msi_attrib.is_msix	= 0;
> -	entry->pci.msi_attrib.is_64		= !!(control & PCI_MSI_FLAGS_64BIT);
> -	entry->pci.msi_attrib.is_virtual    = 0;
> -	entry->pci.msi_attrib.entry_nr	= 0;
> -	entry->pci.msi_attrib.can_mask	= !pci_msi_ignore_mask &&
> -					  !!(control & PCI_MSI_FLAGS_MASKBIT);
> -	entry->pci.msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
> -	entry->pci.msi_attrib.multi_cap	= (control & PCI_MSI_FLAGS_QMASK) >> 1;
> -	entry->pci.msi_attrib.multiple	= ilog2(__roundup_pow_of_two(nvec));
> -
> -	if (control & PCI_MSI_FLAGS_64BIT)
> -		entry->pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
> -	else
> -		entry->pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
> -
> -	/* Save the initial mask status */
> -	if (entry->pci.msi_attrib.can_mask)
> -		pci_read_config_dword(dev, entry->pci.mask_pos, &entry->pci.msi_mask);
> -
> -out:
> -	kfree(masks);
> -	return entry;
> -}
> -
> -static int msi_verify_entries(struct pci_dev *dev)
> -{
> -	struct msi_desc *entry;
> -
> -	if (!dev->no_64bit_msi)
> -		return 0;
> -
> -	for_each_pci_msi_entry(entry, dev) {
> -		if (entry->msg.address_hi) {
> -			pci_err(dev, "arch assigned 64-bit MSI address %#x%08x but device only supports 32 bits\n",
> -				entry->msg.address_hi, entry->msg.address_lo);
> -			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)
> -{
> -	const struct attribute_group **groups;
> -	struct msi_desc *entry;
> -	int ret;
> -
> -	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 */
> -	pci_msi_mask(entry, msi_multi_mask(entry));
> -
> -	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)
> -		goto err;
> -
> -	ret = msi_verify_entries(dev);
> -	if (ret)
> -		goto err;
> -
> -	groups = msi_populate_sysfs(&dev->dev);
> -	if (IS_ERR(groups)) {
> -		ret = PTR_ERR(groups);
> -		goto err;
> -	}
> -
> -	dev->msi_irq_groups = groups;
> -
> -	/* 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;
> -
> -err:
> -	pci_msi_unmask(entry, msi_multi_mask(entry));
> -	free_msi_irqs(dev);
> -	return ret;
> -}
> -
> -static void __iomem *msix_map_region(struct pci_dev *dev,
> -				     unsigned int 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->pci.msi_attrib.is_msix	= 1;
> -		entry->pci.msi_attrib.is_64	= 1;
> -
> -		if (entries)
> -			entry->pci.msi_attrib.entry_nr = entries[i].entry;
> -		else
> -			entry->pci.msi_attrib.entry_nr = i;
> -
> -		entry->pci.msi_attrib.is_virtual =
> -			entry->pci.msi_attrib.entry_nr >= vec_count;
> -
> -		entry->pci.msi_attrib.can_mask	= !pci_msi_ignore_mask &&
> -						  !entry->pci.msi_attrib.is_virtual;
> -
> -		entry->pci.msi_attrib.default_irq	= dev->irq;
> -		entry->pci.mask_base			= base;
> -
> -		if (entry->pci.msi_attrib.can_mask) {
> -			addr = pci_msix_desc_addr(entry);
> -			entry->pci.msix_ctrl = 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;
> -
> -	if (entries) {
> -		for_each_pci_msi_entry(entry, dev) {
> -			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)
> -{
> -	const struct attribute_group **groups;
> -	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;
> -	}
> -
> -	/* Ensure that all table entries are masked. */
> -	msix_mask_all(base, tsize);
> -
> -	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);
> -
> -	groups = msi_populate_sysfs(&dev->dev);
> -	if (IS_ERR(groups)) {
> -		ret = PTR_ERR(groups);
> -		goto out_free;
> -	}
> -
> -	dev->msi_irq_groups = groups;
> -
> -	/* Set MSI-X enabled bits and unmask the function */
> -	pci_intx_for_msi(dev, 0);
> -	dev->msix_enabled = 1;
> -	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_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.
> -	 *
> -	 * The NO_MSI flag can either be set directly by:
> -	 * - arch-specific PCI host bus controller drivers (deprecated)
> -	 * - quirks for specific PCI bridges
> -	 *
> -	 * or indirectly by platform-specific PCI host bridge drivers by
> -	 * advertising the 'msi_domain' property, which results in
> -	 * the NO_MSI flag when no MSI domain is found for this bridge
> -	 * at probe time.
> -	 */
> -	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;
> -
> -	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 */
> -	pci_msi_unmask(desc, msi_multi_mask(desc));
> -
> -	/* Restore dev->irq to its default pin-assertion IRQ */
> -	dev->irq = desc->pci.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_mask(entry);
> -
> -	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->pci.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->pci.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);
> -
> -#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
> - */
> -static 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->pci.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->pci.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->pci.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 */
> -#endif /* CONFIG_PCI_MSI */
> -
> -void pci_msi_init(struct pci_dev *dev)
> -{
> -	u16 ctrl;
> -
> -	/*
> -	 * Disable the MSI hardware to avoid screaming interrupts
> -	 * during boot.  This is the power on reset default so
> -	 * usually this should be a noop.
> -	 */
> -	dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
> -	if (!dev->msi_cap)
> -		return;
> -
> -	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &ctrl);
> -	if (ctrl & PCI_MSI_FLAGS_ENABLE)
> -		pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS,
> -				      ctrl & ~PCI_MSI_FLAGS_ENABLE);
> -
> -	if (!(ctrl & PCI_MSI_FLAGS_64BIT))
> -		dev->no_64bit_msi = 1;
> -}
> -
> -void pci_msix_init(struct pci_dev *dev)
> -{
> -	u16 ctrl;
> -
> -	dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
> -	if (!dev->msix_cap)
> -		return;
> -
> -	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
> -	if (ctrl & PCI_MSIX_FLAGS_ENABLE)
> -		pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS,
> -				      ctrl & ~PCI_MSIX_FLAGS_ENABLE);
> -}
> --- /dev/null
> +++ b/drivers/pci/msi/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Makefile for the PCI/MSI
> +obj-$(CONFIG_PCI)		+= msi.o
> --- /dev/null
> +++ b/drivers/pci/msi/msi.c
> @@ -0,0 +1,1532 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PCI Message Signaled Interrupt (MSI)
> + *
> + * Copyright (C) 2003-2004 Intel
> + * Copyright (C) Tom Long Nguyen (tom.l.nguyen@xxxxxxxxx)
> + * Copyright (C) 2016 Christoph Hellwig.
> + */
> +
> +#include <linux/acpi_iort.h>
> +#include <linux/err.h>
> +#include <linux/export.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/msi.h>
> +#include <linux/of_irq.h>
> +#include <linux/pci.h>
> +
> +#include "../pci.h"
> +
> +#ifdef CONFIG_PCI_MSI
> +
> +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)
> +{
> +	return -EINVAL;
> +}
> +
> +void __weak arch_teardown_msi_irq(unsigned int irq)
> +{
> +}
> +
> +int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
> +{
> +	struct msi_desc *entry;
> +	int ret;
> +
> +	/*
> +	 * 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;
> +}
> +
> +void __weak arch_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);
> +}
> +#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */
> +
> +/*
> + * 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.
> + */
> +static inline __attribute_const__ u32 msi_multi_mask(struct msi_desc *desc)
> +{
> +	/* Don't shift by >= width of type */
> +	if (desc->pci.msi_attrib.multi_cap >= 5)
> +		return 0xffffffff;
> +	return (1 << (1 << desc->pci.msi_attrib.multi_cap)) - 1;
> +}
> +
> +static noinline void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 set)
> +{
> +	raw_spinlock_t *lock = &desc->dev->msi_lock;
> +	unsigned long flags;
> +
> +	if (!desc->pci.msi_attrib.can_mask)
> +		return;
> +
> +	raw_spin_lock_irqsave(lock, flags);
> +	desc->pci.msi_mask &= ~clear;
> +	desc->pci.msi_mask |= set;
> +	pci_write_config_dword(msi_desc_to_pci_dev(desc), desc->pci.mask_pos,
> +			       desc->pci.msi_mask);
> +	raw_spin_unlock_irqrestore(lock, flags);
> +}
> +
> +static inline void pci_msi_mask(struct msi_desc *desc, u32 mask)
> +{
> +	pci_msi_update_mask(desc, 0, mask);
> +}
> +
> +static inline void pci_msi_unmask(struct msi_desc *desc, u32 mask)
> +{
> +	pci_msi_update_mask(desc, mask, 0);
> +}
> +
> +static inline void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
> +{
> +	return desc->pci.mask_base + desc->pci.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.
> + * It does not affect the msi_desc::msix_ctrl cache either. Use with care!
> + */
> +static void pci_msix_write_vector_ctrl(struct msi_desc *desc, u32 ctrl)
> +{
> +	void __iomem *desc_addr = pci_msix_desc_addr(desc);
> +
> +	if (desc->pci.msi_attrib.can_mask)
> +		writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
> +}
> +
> +static inline void pci_msix_mask(struct msi_desc *desc)
> +{
> +	desc->pci.msix_ctrl |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
> +	pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
> +	/* Flush write to device */
> +	readl(desc->pci.mask_base);
> +}
> +
> +static inline void pci_msix_unmask(struct msi_desc *desc)
> +{
> +	desc->pci.msix_ctrl &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
> +	pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
> +}
> +
> +static void __pci_msi_mask_desc(struct msi_desc *desc, u32 mask)
> +{
> +	if (desc->pci.msi_attrib.is_msix)
> +		pci_msix_mask(desc);
> +	else
> +		pci_msi_mask(desc, mask);
> +}
> +
> +static void __pci_msi_unmask_desc(struct msi_desc *desc, u32 mask)
> +{
> +	if (desc->pci.msi_attrib.is_msix)
> +		pci_msix_unmask(desc);
> +	else
> +		pci_msi_unmask(desc, mask);
> +}
> +
> +/**
> + * 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)
> +{
> +	struct msi_desc *desc = irq_data_get_msi_desc(data);
> +
> +	__pci_msi_mask_desc(desc, BIT(data->irq - desc->irq));
> +}
> +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)
> +{
> +	struct msi_desc *desc = irq_data_get_msi_desc(data);
> +
> +	__pci_msi_unmask_desc(desc, BIT(data->irq - desc->irq));
> +}
> +EXPORT_SYMBOL_GPL(pci_msi_unmask_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->pci.msi_attrib.is_msix) {
> +		void __iomem *base = pci_msix_desc_addr(entry);
> +
> +		if (WARN_ON_ONCE(entry->pci.msi_attrib.is_virtual))
> +			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->pci.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->pci.msi_attrib.is_msix) {
> +		void __iomem *base = pci_msix_desc_addr(entry);
> +		u32 ctrl = entry->pci.msix_ctrl;
> +		bool unmasked = !(ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
> +
> +		if (entry->pci.msi_attrib.is_virtual)
> +			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_write_vector_ctrl(entry, ctrl | 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_write_vector_ctrl(entry, ctrl);
> +
> +		/* 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->pci.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->pci.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;
> +	int i;
> +
> +	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) {
> +		msi_destroy_sysfs(&dev->dev, 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->pci.msi_attrib.is_msix) {
> +			if (list_is_last(&entry->list, msi_list))
> +				iounmap(entry->pci.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_msi_set_enable(struct pci_dev *dev, int enable)
> +{
> +	u16 control;
> +
> +	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
> +	control &= ~PCI_MSI_FLAGS_ENABLE;
> +	if (enable)
> +		control |= PCI_MSI_FLAGS_ENABLE;
> +	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
> +}
> +
> +/*
> + * Architecture override returns true when the PCI MSI message should be
> + * written by the generic restore function.
> + */
> +bool __weak arch_restore_msi_irqs(struct pci_dev *dev)
> +{
> +	return true;
> +}
> +
> +static void __pci_restore_msi_state(struct pci_dev *dev)
> +{
> +	struct msi_desc *entry;
> +	u16 control;
> +
> +	if (!dev->msi_enabled)
> +		return;
> +
> +	entry = irq_get_msi_desc(dev->irq);
> +
> +	pci_intx_for_msi(dev, 0);
> +	pci_msi_set_enable(dev, 0);
> +	if (arch_restore_msi_irqs(dev))
> +		__pci_write_msi_msg(entry, &entry->msg);
> +
> +	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
> +	pci_msi_update_mask(entry, 0, 0);
> +	control &= ~PCI_MSI_FLAGS_QSIZE;
> +	control |= (entry->pci.msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
> +	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
> +}
> +
> +static void pci_msix_clear_and_set_ctrl(struct pci_dev *dev, u16 clear, u16 set)
> +{
> +	u16 ctrl;
> +
> +	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
> +	ctrl &= ~clear;
> +	ctrl |= set;
> +	pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, ctrl);
> +}
> +
> +static void __pci_restore_msix_state(struct pci_dev *dev)
> +{
> +	struct msi_desc *entry;
> +	bool write_msg;
> +
> +	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);
> +
> +	write_msg = arch_restore_msi_irqs(dev);
> +
> +	for_each_pci_msi_entry(entry, dev) {
> +		if (write_msg)
> +			__pci_write_msi_msg(entry, &entry->msg);
> +		pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
> +	}
> +
> +	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 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->pci.msi_attrib.is_msix	= 0;
> +	entry->pci.msi_attrib.is_64		= !!(control & PCI_MSI_FLAGS_64BIT);
> +	entry->pci.msi_attrib.is_virtual    = 0;
> +	entry->pci.msi_attrib.entry_nr	= 0;
> +	entry->pci.msi_attrib.can_mask	= !pci_msi_ignore_mask &&
> +					  !!(control & PCI_MSI_FLAGS_MASKBIT);
> +	entry->pci.msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
> +	entry->pci.msi_attrib.multi_cap	= (control & PCI_MSI_FLAGS_QMASK) >> 1;
> +	entry->pci.msi_attrib.multiple	= ilog2(__roundup_pow_of_two(nvec));
> +
> +	if (control & PCI_MSI_FLAGS_64BIT)
> +		entry->pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
> +	else
> +		entry->pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
> +
> +	/* Save the initial mask status */
> +	if (entry->pci.msi_attrib.can_mask)
> +		pci_read_config_dword(dev, entry->pci.mask_pos, &entry->pci.msi_mask);
> +
> +out:
> +	kfree(masks);
> +	return entry;
> +}
> +
> +static int msi_verify_entries(struct pci_dev *dev)
> +{
> +	struct msi_desc *entry;
> +
> +	if (!dev->no_64bit_msi)
> +		return 0;
> +
> +	for_each_pci_msi_entry(entry, dev) {
> +		if (entry->msg.address_hi) {
> +			pci_err(dev, "arch assigned 64-bit MSI address %#x%08x but device only supports 32 bits\n",
> +				entry->msg.address_hi, entry->msg.address_lo);
> +			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)
> +{
> +	const struct attribute_group **groups;
> +	struct msi_desc *entry;
> +	int ret;
> +
> +	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 */
> +	pci_msi_mask(entry, msi_multi_mask(entry));
> +
> +	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)
> +		goto err;
> +
> +	ret = msi_verify_entries(dev);
> +	if (ret)
> +		goto err;
> +
> +	groups = msi_populate_sysfs(&dev->dev);
> +	if (IS_ERR(groups)) {
> +		ret = PTR_ERR(groups);
> +		goto err;
> +	}
> +
> +	dev->msi_irq_groups = groups;
> +
> +	/* 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;
> +
> +err:
> +	pci_msi_unmask(entry, msi_multi_mask(entry));
> +	free_msi_irqs(dev);
> +	return ret;
> +}
> +
> +static void __iomem *msix_map_region(struct pci_dev *dev,
> +				     unsigned int 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->pci.msi_attrib.is_msix	= 1;
> +		entry->pci.msi_attrib.is_64	= 1;
> +
> +		if (entries)
> +			entry->pci.msi_attrib.entry_nr = entries[i].entry;
> +		else
> +			entry->pci.msi_attrib.entry_nr = i;
> +
> +		entry->pci.msi_attrib.is_virtual =
> +			entry->pci.msi_attrib.entry_nr >= vec_count;
> +
> +		entry->pci.msi_attrib.can_mask	= !pci_msi_ignore_mask &&
> +						  !entry->pci.msi_attrib.is_virtual;
> +
> +		entry->pci.msi_attrib.default_irq	= dev->irq;
> +		entry->pci.mask_base			= base;
> +
> +		if (entry->pci.msi_attrib.can_mask) {
> +			addr = pci_msix_desc_addr(entry);
> +			entry->pci.msix_ctrl = 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;
> +
> +	if (entries) {
> +		for_each_pci_msi_entry(entry, dev) {
> +			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)
> +{
> +	const struct attribute_group **groups;
> +	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;
> +	}
> +
> +	/* Ensure that all table entries are masked. */
> +	msix_mask_all(base, tsize);
> +
> +	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);
> +
> +	groups = msi_populate_sysfs(&dev->dev);
> +	if (IS_ERR(groups)) {
> +		ret = PTR_ERR(groups);
> +		goto out_free;
> +	}
> +
> +	dev->msi_irq_groups = groups;
> +
> +	/* Set MSI-X enabled bits and unmask the function */
> +	pci_intx_for_msi(dev, 0);
> +	dev->msix_enabled = 1;
> +	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_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.
> +	 *
> +	 * The NO_MSI flag can either be set directly by:
> +	 * - arch-specific PCI host bus controller drivers (deprecated)
> +	 * - quirks for specific PCI bridges
> +	 *
> +	 * or indirectly by platform-specific PCI host bridge drivers by
> +	 * advertising the 'msi_domain' property, which results in
> +	 * the NO_MSI flag when no MSI domain is found for this bridge
> +	 * at probe time.
> +	 */
> +	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;
> +
> +	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 */
> +	pci_msi_unmask(desc, msi_multi_mask(desc));
> +
> +	/* Restore dev->irq to its default pin-assertion IRQ */
> +	dev->irq = desc->pci.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_mask(entry);
> +
> +	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->pci.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->pci.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);
> +
> +#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
> + */
> +static 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->pci.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->pci.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->pci.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 */
> +#endif /* CONFIG_PCI_MSI */
> +
> +void pci_msi_init(struct pci_dev *dev)
> +{
> +	u16 ctrl;
> +
> +	/*
> +	 * Disable the MSI hardware to avoid screaming interrupts
> +	 * during boot.  This is the power on reset default so
> +	 * usually this should be a noop.
> +	 */
> +	dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
> +	if (!dev->msi_cap)
> +		return;
> +
> +	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &ctrl);
> +	if (ctrl & PCI_MSI_FLAGS_ENABLE)
> +		pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS,
> +				      ctrl & ~PCI_MSI_FLAGS_ENABLE);
> +
> +	if (!(ctrl & PCI_MSI_FLAGS_64BIT))
> +		dev->no_64bit_msi = 1;
> +}
> +
> +void pci_msix_init(struct pci_dev *dev)
> +{
> +	u16 ctrl;
> +
> +	dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
> +	if (!dev->msix_cap)
> +		return;
> +
> +	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
> +	if (ctrl & PCI_MSIX_FLAGS_ENABLE)
> +		pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS,
> +				      ctrl & ~PCI_MSIX_FLAGS_ENABLE);
> +}
>