486 lines
14 KiB
C
486 lines
14 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* PCI Message Signaled Interrupt (MSI) - irqdomain support
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*/
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#include <linux/acpi_iort.h>
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#include <linux/irqdomain.h>
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#include <linux/of_irq.h>
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#include "msi.h"
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int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
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{
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struct irq_domain *domain;
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domain = dev_get_msi_domain(&dev->dev);
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if (domain && irq_domain_is_hierarchy(domain))
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return msi_domain_alloc_irqs_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN, nvec);
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return pci_msi_legacy_setup_msi_irqs(dev, nvec, type);
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}
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void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
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{
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struct irq_domain *domain;
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domain = dev_get_msi_domain(&dev->dev);
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if (domain && irq_domain_is_hierarchy(domain)) {
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msi_domain_free_irqs_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN);
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} else {
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pci_msi_legacy_teardown_msi_irqs(dev);
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msi_free_msi_descs(&dev->dev);
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}
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}
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/**
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* pci_msi_domain_write_msg - Helper to write MSI message to PCI config space
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* @irq_data: Pointer to interrupt data of the MSI interrupt
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* @msg: Pointer to the message
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*/
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static void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg)
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{
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struct msi_desc *desc = irq_data_get_msi_desc(irq_data);
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/*
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* For MSI-X desc->irq is always equal to irq_data->irq. For
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* MSI only the first interrupt of MULTI MSI passes the test.
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*/
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if (desc->irq == irq_data->irq)
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__pci_write_msi_msg(desc, msg);
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}
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/**
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* pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source
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* @desc: Pointer to the MSI descriptor
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*
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* The ID number is only used within the irqdomain.
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*/
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static irq_hw_number_t pci_msi_domain_calc_hwirq(struct msi_desc *desc)
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{
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struct pci_dev *dev = msi_desc_to_pci_dev(desc);
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return (irq_hw_number_t)desc->msi_index |
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pci_dev_id(dev) << 11 |
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(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
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}
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static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,
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struct msi_desc *desc)
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{
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arg->desc = desc;
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arg->hwirq = pci_msi_domain_calc_hwirq(desc);
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}
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static struct msi_domain_ops pci_msi_domain_ops_default = {
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.set_desc = pci_msi_domain_set_desc,
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};
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static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info)
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{
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struct msi_domain_ops *ops = info->ops;
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if (ops == NULL) {
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info->ops = &pci_msi_domain_ops_default;
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} else {
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if (ops->set_desc == NULL)
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ops->set_desc = pci_msi_domain_set_desc;
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}
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}
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static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info)
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{
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struct irq_chip *chip = info->chip;
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BUG_ON(!chip);
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if (!chip->irq_write_msi_msg)
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chip->irq_write_msi_msg = pci_msi_domain_write_msg;
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if (!chip->irq_mask)
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chip->irq_mask = pci_msi_mask_irq;
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if (!chip->irq_unmask)
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chip->irq_unmask = pci_msi_unmask_irq;
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}
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/**
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* pci_msi_create_irq_domain - Create a MSI interrupt domain
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* @fwnode: Optional fwnode of the interrupt controller
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* @info: MSI domain info
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* @parent: Parent irq domain
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*
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* Updates the domain and chip ops and creates a MSI interrupt domain.
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*
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* Returns:
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* A domain pointer or NULL in case of failure.
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*/
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struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
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struct msi_domain_info *info,
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struct irq_domain *parent)
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{
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if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE))
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info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
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if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
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pci_msi_domain_update_dom_ops(info);
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if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
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pci_msi_domain_update_chip_ops(info);
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/* Let the core code free MSI descriptors when freeing interrupts */
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info->flags |= MSI_FLAG_FREE_MSI_DESCS;
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info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS;
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if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
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info->flags |= MSI_FLAG_MUST_REACTIVATE;
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/* PCI-MSI is oneshot-safe */
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info->chip->flags |= IRQCHIP_ONESHOT_SAFE;
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/* Let the core update the bus token */
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info->bus_token = DOMAIN_BUS_PCI_MSI;
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return msi_create_irq_domain(fwnode, info, parent);
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}
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EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain);
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/*
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* Per device MSI[-X] domain functionality
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*/
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static void pci_device_domain_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
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{
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arg->desc = desc;
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arg->hwirq = desc->msi_index;
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}
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static void pci_irq_mask_msi(struct irq_data *data)
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{
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struct msi_desc *desc = irq_data_get_msi_desc(data);
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pci_msi_mask(desc, BIT(data->irq - desc->irq));
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}
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static void pci_irq_unmask_msi(struct irq_data *data)
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{
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struct msi_desc *desc = irq_data_get_msi_desc(data);
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pci_msi_unmask(desc, BIT(data->irq - desc->irq));
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}
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#ifdef CONFIG_GENERIC_IRQ_RESERVATION_MODE
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# define MSI_REACTIVATE MSI_FLAG_MUST_REACTIVATE
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#else
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# define MSI_REACTIVATE 0
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#endif
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#define MSI_COMMON_FLAGS (MSI_FLAG_FREE_MSI_DESCS | \
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MSI_FLAG_ACTIVATE_EARLY | \
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MSI_FLAG_DEV_SYSFS | \
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MSI_REACTIVATE)
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static const struct msi_domain_template pci_msi_template = {
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.chip = {
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.name = "PCI-MSI",
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.irq_mask = pci_irq_mask_msi,
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.irq_unmask = pci_irq_unmask_msi,
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.irq_write_msi_msg = pci_msi_domain_write_msg,
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.flags = IRQCHIP_ONESHOT_SAFE,
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},
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.ops = {
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.set_desc = pci_device_domain_set_desc,
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},
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.info = {
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.flags = MSI_COMMON_FLAGS | MSI_FLAG_MULTI_PCI_MSI,
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.bus_token = DOMAIN_BUS_PCI_DEVICE_MSI,
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},
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};
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static void pci_irq_mask_msix(struct irq_data *data)
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{
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pci_msix_mask(irq_data_get_msi_desc(data));
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}
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static void pci_irq_unmask_msix(struct irq_data *data)
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{
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pci_msix_unmask(irq_data_get_msi_desc(data));
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}
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static void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
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struct msi_desc *desc)
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{
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/* Don't fiddle with preallocated MSI descriptors */
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if (!desc->pci.mask_base)
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msix_prepare_msi_desc(to_pci_dev(desc->dev), desc);
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}
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static const struct msi_domain_template pci_msix_template = {
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.chip = {
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.name = "PCI-MSIX",
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.irq_mask = pci_irq_mask_msix,
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.irq_unmask = pci_irq_unmask_msix,
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.irq_write_msi_msg = pci_msi_domain_write_msg,
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.flags = IRQCHIP_ONESHOT_SAFE,
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},
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.ops = {
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.prepare_desc = pci_msix_prepare_desc,
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.set_desc = pci_device_domain_set_desc,
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},
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.info = {
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.flags = MSI_COMMON_FLAGS | MSI_FLAG_PCI_MSIX |
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MSI_FLAG_PCI_MSIX_ALLOC_DYN,
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.bus_token = DOMAIN_BUS_PCI_DEVICE_MSIX,
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},
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};
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static bool pci_match_device_domain(struct pci_dev *pdev, enum irq_domain_bus_token bus_token)
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{
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return msi_match_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, bus_token);
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}
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static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_domain_template *tmpl,
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unsigned int hwsize)
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{
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struct irq_domain *domain = dev_get_msi_domain(&pdev->dev);
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if (!domain || !irq_domain_is_msi_parent(domain))
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return true;
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return msi_create_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, tmpl,
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hwsize, NULL, NULL);
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}
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/**
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* pci_setup_msi_device_domain - Setup a device MSI interrupt domain
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* @pdev: The PCI device to create the domain on
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*
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* Return:
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* True when:
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* - The device does not have a MSI parent irq domain associated,
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* which keeps the legacy architecture specific and the global
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* PCI/MSI domain models working
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* - The MSI domain exists already
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* - The MSI domain was successfully allocated
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* False when:
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* - MSI-X is enabled
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* - The domain creation fails.
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*
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* The created MSI domain is preserved until:
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* - The device is removed
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* - MSI is disabled and a MSI-X domain is created
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*/
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bool pci_setup_msi_device_domain(struct pci_dev *pdev)
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{
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if (WARN_ON_ONCE(pdev->msix_enabled))
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return false;
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if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI))
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return true;
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if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
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msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
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return pci_create_device_domain(pdev, &pci_msi_template, 1);
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}
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/**
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* pci_setup_msix_device_domain - Setup a device MSI-X interrupt domain
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* @pdev: The PCI device to create the domain on
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* @hwsize: The size of the MSI-X vector table
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*
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* Return:
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* True when:
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* - The device does not have a MSI parent irq domain associated,
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* which keeps the legacy architecture specific and the global
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* PCI/MSI domain models working
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* - The MSI-X domain exists already
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* - The MSI-X domain was successfully allocated
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* False when:
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* - MSI is enabled
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* - The domain creation fails.
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*
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* The created MSI-X domain is preserved until:
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* - The device is removed
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* - MSI-X is disabled and a MSI domain is created
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*/
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bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize)
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{
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if (WARN_ON_ONCE(pdev->msi_enabled))
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return false;
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if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
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return true;
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if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI))
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msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
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return pci_create_device_domain(pdev, &pci_msix_template, hwsize);
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}
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/**
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* pci_msi_domain_supports - Check for support of a particular feature flag
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* @pdev: The PCI device to operate on
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* @feature_mask: The feature mask to check for (full match)
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* @mode: If ALLOW_LEGACY this grants the feature when there is no irq domain
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* associated to the device. If DENY_LEGACY the lack of an irq domain
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* makes the feature unsupported
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*/
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bool pci_msi_domain_supports(struct pci_dev *pdev, unsigned int feature_mask,
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enum support_mode mode)
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{
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struct msi_domain_info *info;
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struct irq_domain *domain;
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unsigned int supported;
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domain = dev_get_msi_domain(&pdev->dev);
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if (!domain || !irq_domain_is_hierarchy(domain))
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return mode == ALLOW_LEGACY;
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if (!irq_domain_is_msi_parent(domain)) {
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/*
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* For "global" PCI/MSI interrupt domains the associated
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* msi_domain_info::flags is the authoritive source of
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* information.
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*/
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info = domain->host_data;
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supported = info->flags;
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} else {
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/*
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* For MSI parent domains the supported feature set
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* is avaliable in the parent ops. This makes checks
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* possible before actually instantiating the
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* per device domain because the parent is never
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* expanding the PCI/MSI functionality.
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*/
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supported = domain->msi_parent_ops->supported_flags;
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}
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return (supported & feature_mask) == feature_mask;
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}
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/**
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* pci_create_ims_domain - Create a secondary IMS domain for a PCI device
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* @pdev: The PCI device to operate on
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* @template: The MSI info template which describes the domain
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* @hwsize: The size of the hardware entry table or 0 if the domain
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* is purely software managed
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* @data: Optional pointer to domain specific data to be stored
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* in msi_domain_info::data
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*
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* Return: True on success, false otherwise
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*
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* An IMS domain is expected to have the following constraints:
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* - The index space is managed by the core code
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*
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* - There is no requirement for consecutive index ranges
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*
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* - The interrupt chip must provide the following callbacks:
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* - irq_mask()
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* - irq_unmask()
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* - irq_write_msi_msg()
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*
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* - The interrupt chip must provide the following optional callbacks
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* when the irq_mask(), irq_unmask() and irq_write_msi_msg() callbacks
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* cannot operate directly on hardware, e.g. in the case that the
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* interrupt message store is in queue memory:
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* - irq_bus_lock()
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* - irq_bus_unlock()
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*
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* These callbacks are invoked from preemptible task context and are
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* allowed to sleep. In this case the mandatory callbacks above just
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* store the information. The irq_bus_unlock() callback is supposed
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* to make the change effective before returning.
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*
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* - Interrupt affinity setting is handled by the underlying parent
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* interrupt domain and communicated to the IMS domain via
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* irq_write_msi_msg().
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*
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* The domain is automatically destroyed when the PCI device is removed.
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*/
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bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template,
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unsigned int hwsize, void *data)
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{
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struct irq_domain *domain = dev_get_msi_domain(&pdev->dev);
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if (!domain || !irq_domain_is_msi_parent(domain))
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return false;
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if (template->info.bus_token != DOMAIN_BUS_PCI_DEVICE_IMS ||
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!(template->info.flags & MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS) ||
|
||
|
!(template->info.flags & MSI_FLAG_FREE_MSI_DESCS) ||
|
||
|
!template->chip.irq_mask || !template->chip.irq_unmask ||
|
||
|
!template->chip.irq_write_msi_msg || template->chip.irq_set_affinity)
|
||
|
return false;
|
||
|
|
||
|
return msi_create_device_irq_domain(&pdev->dev, MSI_SECONDARY_DOMAIN, template,
|
||
|
hwsize, data, NULL);
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(pci_create_ims_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;
|
||
|
}
|