PoC code only. All sorts of missing checks etc.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
arch/x86/kernel/apic/msi.c | 3 ++
drivers/pci/msi/api.c | 14 ++++++
drivers/pci/msi/irqdomain.c | 87 +++++++++++++++++++++++++++++++++++++
include/linux/msi.h | 5 +++
include/linux/pci.h | 3 ++
kernel/irq/msi.c | 5 +++
6 files changed, 117 insertions(+)
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
index 340769242dea..8ab4391d4559 100644
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -218,6 +218,9 @@ static bool x86_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
case DOMAIN_BUS_DMAR:
case DOMAIN_BUS_AMDVI:
break;
+ case DOMAIN_BUS_PCI_DEVICE_MSIX:
+ /* Currently needed just for the PCI MSI-X subdevice handling */
+ break;
default:
WARN_ON_ONCE(1);
return false;
diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
index b956ce591f96..2b4c15102671 100644
--- a/drivers/pci/msi/api.c
+++ b/drivers/pci/msi/api.c
@@ -179,6 +179,20 @@ void pci_msix_free_irq(struct pci_dev *dev, struct msi_map map)
}
EXPORT_SYMBOL_GPL(pci_msix_free_irq);
+struct msi_map pci_subdev_msix_alloc_irq_at(struct device *dev, unsigned int index,
+ const struct irq_affinity_desc *affdesc)
+{
+ //missing sanity checks
+ return msi_domain_alloc_irq_at(dev, MSI_DEFAULT_DOMAIN, index, affdesc, NULL);
+}
+EXPORT_SYMBOL_GPL(pci_subdev_msix_alloc_irq_at);
+
+void pci_subdev_msix_free_irq(struct device *dev, struct msi_map map)
+{
+ msi_domain_free_irqs_range(dev, MSI_DEFAULT_DOMAIN, map.index, map.index);
+}
+EXPORT_SYMBOL_GPL(pci_subdev_msix_free_irq);
+
/**
* pci_disable_msix() - Disable MSI-X interrupt mode on device
* @dev: the PCI device to operate on
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index 569125726b3e..48357a8054ff 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -444,3 +444,90 @@ struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
DOMAIN_BUS_PCI_MSI);
return dom;
}
+
+static const struct msi_parent_ops pci_msix_parent_ops = {
+ .supported_flags = MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN,
+ .prefix = "PCI-MSIX-PROXY-",
+ .init_dev_msi_info = msi_parent_init_dev_msi_info,
+};
+
+int pci_msi_enable_parent_domain(struct pci_dev *pdev)
+{
+ struct irq_domain *msix_dom;
+ /* TGLX: Validate has v2 parent domain */
+ /* TGLX: validate msix enabled */
+ /* TGLX: Validate msix domain supports dynamics msi-x */
+
+ /* Enable PCI device parent domain */
+ msix_dom = dev_msi_get_msix_device_domain(&pdev->dev);
+ msix_dom->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT;
+ msix_dom->msi_parent_ops = &pci_msix_parent_ops;
+ return 0;
+}
+
+void pci_msi_init_subdevice(struct pci_dev *pdev, struct device *dev)
+{
+ dev_set_msi_domain(dev, dev_msi_get_msix_device_domain(&pdev->dev));
+}
+
+static bool pci_subdev_create_device_domain(struct device *dev, const struct msi_domain_template *tmpl,
+ unsigned int hwsize)
+{
+ struct irq_domain *domain = dev_get_msi_domain(dev);
+
+ if (!domain || !irq_domain_is_msi_parent(domain))
+ return true;
+
+ return msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN, tmpl,
+ hwsize, NULL, NULL);
+}
+
+static void pci_subdev_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
+ struct msi_desc *desc)
+{
+ struct device *parent = desc->dev->parent;
+
+ if (!desc->pci.mask_base) {
+ /* Not elegant - but needed for irq affinity to work? */
+ desc->dev = parent;
+ msix_prepare_msi_desc(to_pci_dev(parent), desc);
+ }
+}
+
+static const struct msi_domain_template subdev_template = {
+ .chip = {
+ .name = "SUBDEV",
+ .irq_mask = irq_chip_unmask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_write_msi_msg = pci_msi_domain_write_msg,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+ .flags = IRQCHIP_ONESHOT_SAFE,
+ },
+ .ops = {
+ /*
+ * RFC: Sets the desc->dev to the parent PCI device
+ * Needed for
+ * irq_setup_affinity() ->
+ * msi_set_affinity() ->
+ * parent = irq_d->parent_data;
+ * parent->chip->irq_set_affinity() to work.
+ * That could be made more flexible perhaps as
+ * currently it makes assumption that parent of
+ * the MSI device is the one to set the affinity on.
+ */
+ .prepare_desc = pci_subdev_msix_prepare_desc,
+ /* Works because the desc->dev is the parent PCI device */
+ .set_desc = pci_msi_domain_set_desc,
+ },
+ .info = {
+ .flags = MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN |
+ MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_USE_DEF_DOM_OPS,
+ .bus_token = DOMAIN_BUS_PCI_DEVICE_MSIX,
+ },
+};
+
+bool pci_subdev_setup_device_domain(struct device *dev, unsigned int hwsize)
+{
+ return pci_subdev_create_device_domain(dev, &subdev_template, hwsize);
+}
+EXPORT_SYMBOL_GPL(pci_subdev_setup_device_domain);
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 944979763825..ff81b4dcc1d9 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -656,8 +656,13 @@ void pci_msi_unmask_irq(struct irq_data *data);
struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
struct msi_domain_info *info,
struct irq_domain *parent);
+int pci_msi_enable_parent_domain(struct pci_dev *pdev);
+struct irq_domain *pci_msi_get_msix_device_domain(struct device *dev);
u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
+struct irq_domain *dev_msi_get_msix_device_domain(struct device *dev);
+void pci_msi_init_subdevice(struct pci_dev *pdev, struct device *dev);
+bool pci_subdev_setup_device_domain(struct device *dev, unsigned int hwsize);
#else /* CONFIG_PCI_MSI */
static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
{
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 225de9be3006..460551f1bd6e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1679,6 +1679,9 @@ struct msi_map pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
const struct irq_affinity_desc *affdesc);
void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map);
+struct msi_map pci_subdev_msix_alloc_irq_at(struct device *dev, unsigned int index,
+ const struct irq_affinity_desc *affdesc);
+void pci_subdev_msix_free_irq(struct device *dev, struct msi_map map);
void pci_free_irq_vectors(struct pci_dev *dev);
int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev, int vec);
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 5fa0547ece0c..d55a91c7a496 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1720,3 +1720,8 @@ bool msi_device_has_isolated_msi(struct device *dev)
return arch_is_isolated_msi();
}
EXPORT_SYMBOL_GPL(msi_device_has_isolated_msi);
+struct irq_domain *dev_msi_get_msix_device_domain(struct device *dev)
+{
+ return dev->msi.data->__domains[0].domain;
+}
+
--
2.43.0
