PCI/MSI: Fix MSIs for generic hosts that use device-tree's "msi-map"

Since commit 9ec37efb87 ("PCI/MSI: Make pci_host_common_probe() declare
its reliance on MSI domains"), platforms that rely on the "msi-map"
device-tree property don't get MSIs anymore.

On the Arm Fast Model for example [1], the host bridge doesn't have a
"msi-parent" property since it doesn't itself generate MSIs, and so doesn't
get a MSI domain. It has an "msi-map" property instead to describe MSI
controllers of child devices. As a result, due to the new msi_domain check
in pci_register_host_bridge(), the whole bus gets PCI_BUS_FLAGS_NO_MSI.

Check whether the root complex has an "msi-map" property before giving
up on MSIs.

[1] arch/arm64/boot/dts/arm/fvp-base-revc.dts

Fixes: 9ec37efb87 ("PCI/MSI: Make pci_host_common_probe() declare its reliance on MSI domains")
Link: https://lore.kernel.org/r/20210510173129.750496-1-jean-philippe@linaro.org
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Jean-Philippe Brucker 2021-05-10 19:31:30 +02:00 committed by Bjorn Helgaas
parent 2ee4c8a268
commit 85aabbd7b3
3 changed files with 11 additions and 1 deletions

View File

@ -103,6 +103,13 @@ struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
#endif
}
bool pci_host_of_has_msi_map(struct device *dev)
{
if (dev && dev->of_node)
return of_get_property(dev->of_node, "msi-map", NULL);
return false;
}
static inline int __of_pci_pci_compare(struct device_node *node,
unsigned int data)
{

View File

@ -925,7 +925,8 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
device_enable_async_suspend(bus->bridge);
pci_set_bus_of_node(bus);
pci_set_bus_msi_domain(bus);
if (bridge->msi_domain && !dev_get_msi_domain(&bus->dev))
if (bridge->msi_domain && !dev_get_msi_domain(&bus->dev) &&
!pci_host_of_has_msi_map(parent))
bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
if (!parent)

View File

@ -2344,6 +2344,7 @@ int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
struct device_node;
struct irq_domain;
struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus);
bool pci_host_of_has_msi_map(struct device *dev);
/* Arch may override this (weak) */
struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus);
@ -2351,6 +2352,7 @@ struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus);
#else /* CONFIG_OF */
static inline struct irq_domain *
pci_host_bridge_of_msi_domain(struct pci_bus *bus) { return NULL; }
static inline bool pci_host_of_has_msi_map(struct device *dev) { return false; }
#endif /* CONFIG_OF */
static inline struct device_node *