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path: root/drivers/pci/msi/irqdomain.c
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Diffstat (limited to 'drivers/pci/msi/irqdomain.c')
-rw-r--r--drivers/pci/msi/irqdomain.c485
1 files changed, 485 insertions, 0 deletions
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
new file mode 100644
index 0000000000..c8be056c24
--- /dev/null
+++ b/drivers/pci/msi/irqdomain.c
@@ -0,0 +1,485 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Message Signaled Interrupt (MSI) - irqdomain support
+ */
+#include <linux/acpi_iort.h>
+#include <linux/irqdomain.h>
+#include <linux/of_irq.h>
+
+#include "msi.h"
+
+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_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN, nvec);
+
+ return pci_msi_legacy_setup_msi_irqs(dev, nvec, type);
+}
+
+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_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN);
+ } else {
+ pci_msi_legacy_teardown_msi_irqs(dev);
+ msi_free_msi_descs(&dev->dev);
+ }
+}
+
+/**
+ * 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->msi_index |
+ pci_dev_id(dev) << 11 |
+ (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
+}
+
+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,
+};
+
+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;
+ }
+}
+
+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)
+{
+ 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);
+
+ /* Let the core code free MSI descriptors when freeing interrupts */
+ info->flags |= MSI_FLAG_FREE_MSI_DESCS;
+
+ info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS;
+ 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;
+ /* Let the core update the bus token */
+ info->bus_token = DOMAIN_BUS_PCI_MSI;
+
+ return msi_create_irq_domain(fwnode, info, parent);
+}
+EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain);
+
+/*
+ * Per device MSI[-X] domain functionality
+ */
+static void pci_device_domain_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+{
+ arg->desc = desc;
+ arg->hwirq = desc->msi_index;
+}
+
+static void pci_irq_mask_msi(struct irq_data *data)
+{
+ struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+ pci_msi_mask(desc, BIT(data->irq - desc->irq));
+}
+
+static void pci_irq_unmask_msi(struct irq_data *data)
+{
+ struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+ pci_msi_unmask(desc, BIT(data->irq - desc->irq));
+}
+
+#ifdef CONFIG_GENERIC_IRQ_RESERVATION_MODE
+# define MSI_REACTIVATE MSI_FLAG_MUST_REACTIVATE
+#else
+# define MSI_REACTIVATE 0
+#endif
+
+#define MSI_COMMON_FLAGS (MSI_FLAG_FREE_MSI_DESCS | \
+ MSI_FLAG_ACTIVATE_EARLY | \
+ MSI_FLAG_DEV_SYSFS | \
+ MSI_REACTIVATE)
+
+static const struct msi_domain_template pci_msi_template = {
+ .chip = {
+ .name = "PCI-MSI",
+ .irq_mask = pci_irq_mask_msi,
+ .irq_unmask = pci_irq_unmask_msi,
+ .irq_write_msi_msg = pci_msi_domain_write_msg,
+ .flags = IRQCHIP_ONESHOT_SAFE,
+ },
+
+ .ops = {
+ .set_desc = pci_device_domain_set_desc,
+ },
+
+ .info = {
+ .flags = MSI_COMMON_FLAGS | MSI_FLAG_MULTI_PCI_MSI,
+ .bus_token = DOMAIN_BUS_PCI_DEVICE_MSI,
+ },
+};
+
+static void pci_irq_mask_msix(struct irq_data *data)
+{
+ pci_msix_mask(irq_data_get_msi_desc(data));
+}
+
+static void pci_irq_unmask_msix(struct irq_data *data)
+{
+ pci_msix_unmask(irq_data_get_msi_desc(data));
+}
+
+static void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
+ struct msi_desc *desc)
+{
+ /* Don't fiddle with preallocated MSI descriptors */
+ if (!desc->pci.mask_base)
+ msix_prepare_msi_desc(to_pci_dev(desc->dev), desc);
+}
+
+static const struct msi_domain_template pci_msix_template = {
+ .chip = {
+ .name = "PCI-MSIX",
+ .irq_mask = pci_irq_mask_msix,
+ .irq_unmask = pci_irq_unmask_msix,
+ .irq_write_msi_msg = pci_msi_domain_write_msg,
+ .flags = IRQCHIP_ONESHOT_SAFE,
+ },
+
+ .ops = {
+ .prepare_desc = pci_msix_prepare_desc,
+ .set_desc = pci_device_domain_set_desc,
+ },
+
+ .info = {
+ .flags = MSI_COMMON_FLAGS | MSI_FLAG_PCI_MSIX |
+ MSI_FLAG_PCI_MSIX_ALLOC_DYN,
+ .bus_token = DOMAIN_BUS_PCI_DEVICE_MSIX,
+ },
+};
+
+static bool pci_match_device_domain(struct pci_dev *pdev, enum irq_domain_bus_token bus_token)
+{
+ return msi_match_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, bus_token);
+}
+
+static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_domain_template *tmpl,
+ unsigned int hwsize)
+{
+ struct irq_domain *domain = dev_get_msi_domain(&pdev->dev);
+
+ if (!domain || !irq_domain_is_msi_parent(domain))
+ return true;
+
+ return msi_create_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, tmpl,
+ hwsize, NULL, NULL);
+}
+
+/**
+ * pci_setup_msi_device_domain - Setup a device MSI interrupt domain
+ * @pdev: The PCI device to create the domain on
+ *
+ * Return:
+ * True when:
+ * - The device does not have a MSI parent irq domain associated,
+ * which keeps the legacy architecture specific and the global
+ * PCI/MSI domain models working
+ * - The MSI domain exists already
+ * - The MSI domain was successfully allocated
+ * False when:
+ * - MSI-X is enabled
+ * - The domain creation fails.
+ *
+ * The created MSI domain is preserved until:
+ * - The device is removed
+ * - MSI is disabled and a MSI-X domain is created
+ */
+bool pci_setup_msi_device_domain(struct pci_dev *pdev)
+{
+ if (WARN_ON_ONCE(pdev->msix_enabled))
+ return false;
+
+ if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI))
+ return true;
+ if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
+ msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
+
+ return pci_create_device_domain(pdev, &pci_msi_template, 1);
+}
+
+/**
+ * pci_setup_msix_device_domain - Setup a device MSI-X interrupt domain
+ * @pdev: The PCI device to create the domain on
+ * @hwsize: The size of the MSI-X vector table
+ *
+ * Return:
+ * True when:
+ * - The device does not have a MSI parent irq domain associated,
+ * which keeps the legacy architecture specific and the global
+ * PCI/MSI domain models working
+ * - The MSI-X domain exists already
+ * - The MSI-X domain was successfully allocated
+ * False when:
+ * - MSI is enabled
+ * - The domain creation fails.
+ *
+ * The created MSI-X domain is preserved until:
+ * - The device is removed
+ * - MSI-X is disabled and a MSI domain is created
+ */
+bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize)
+{
+ if (WARN_ON_ONCE(pdev->msi_enabled))
+ return false;
+
+ if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
+ return true;
+ if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI))
+ msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
+
+ return pci_create_device_domain(pdev, &pci_msix_template, hwsize);
+}
+
+/**
+ * pci_msi_domain_supports - Check for support of a particular feature flag
+ * @pdev: The PCI device to operate on
+ * @feature_mask: The feature mask to check for (full match)
+ * @mode: If ALLOW_LEGACY this grants the feature when there is no irq domain
+ * associated to the device. If DENY_LEGACY the lack of an irq domain
+ * makes the feature unsupported
+ */
+bool pci_msi_domain_supports(struct pci_dev *pdev, unsigned int feature_mask,
+ enum support_mode mode)
+{
+ struct msi_domain_info *info;
+ struct irq_domain *domain;
+ unsigned int supported;
+
+ domain = dev_get_msi_domain(&pdev->dev);
+
+ if (!domain || !irq_domain_is_hierarchy(domain))
+ return mode == ALLOW_LEGACY;
+
+ if (!irq_domain_is_msi_parent(domain)) {
+ /*
+ * For "global" PCI/MSI interrupt domains the associated
+ * msi_domain_info::flags is the authoritative source of
+ * information.
+ */
+ info = domain->host_data;
+ supported = info->flags;
+ } else {
+ /*
+ * For MSI parent domains the supported feature set
+ * is available in the parent ops. This makes checks
+ * possible before actually instantiating the
+ * per device domain because the parent is never
+ * expanding the PCI/MSI functionality.
+ */
+ supported = domain->msi_parent_ops->supported_flags;
+ }
+
+ return (supported & feature_mask) == feature_mask;
+}
+
+/**
+ * pci_create_ims_domain - Create a secondary IMS domain for a PCI device
+ * @pdev: The PCI device to operate on
+ * @template: The MSI info template which describes the domain
+ * @hwsize: The size of the hardware entry table or 0 if the domain
+ * is purely software managed
+ * @data: Optional pointer to domain specific data to be stored
+ * in msi_domain_info::data
+ *
+ * Return: True on success, false otherwise
+ *
+ * An IMS domain is expected to have the following constraints:
+ * - The index space is managed by the core code
+ *
+ * - There is no requirement for consecutive index ranges
+ *
+ * - The interrupt chip must provide the following callbacks:
+ * - irq_mask()
+ * - irq_unmask()
+ * - irq_write_msi_msg()
+ *
+ * - The interrupt chip must provide the following optional callbacks
+ * when the irq_mask(), irq_unmask() and irq_write_msi_msg() callbacks
+ * cannot operate directly on hardware, e.g. in the case that the
+ * interrupt message store is in queue memory:
+ * - irq_bus_lock()
+ * - irq_bus_unlock()
+ *
+ * These callbacks are invoked from preemptible task context and are
+ * allowed to sleep. In this case the mandatory callbacks above just
+ * store the information. The irq_bus_unlock() callback is supposed
+ * to make the change effective before returning.
+ *
+ * - Interrupt affinity setting is handled by the underlying parent
+ * interrupt domain and communicated to the IMS domain via
+ * irq_write_msi_msg().
+ *
+ * The domain is automatically destroyed when the PCI device is removed.
+ */
+bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template,
+ unsigned int hwsize, void *data)
+{
+ struct irq_domain *domain = dev_get_msi_domain(&pdev->dev);
+
+ if (!domain || !irq_domain_is_msi_parent(domain))
+ return false;
+
+ if (template->info.bus_token != DOMAIN_BUS_PCI_DEVICE_IMS ||
+ !(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;
+}