diff options
Diffstat (limited to 'target/linux/generic/backport-5.15/821-v5.13-let-pci-host-bridges-declar-their-reliance-on-msi-domains.patch')
| -rw-r--r-- | target/linux/generic/backport-5.15/821-v5.13-let-pci-host-bridges-declar-their-reliance-on-msi-domains.patch | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.15/821-v5.13-let-pci-host-bridges-declar-their-reliance-on-msi-domains.patch b/target/linux/generic/backport-5.15/821-v5.13-let-pci-host-bridges-declar-their-reliance-on-msi-domains.patch new file mode 100644 index 0000000000..854dc34c42 --- /dev/null +++ b/target/linux/generic/backport-5.15/821-v5.13-let-pci-host-bridges-declar-their-reliance-on-msi-domains.patch @@ -0,0 +1,44 @@ +From 94e89b145371b68fa0ea294855adebcd03e0522e Mon Sep 17 00:00:00 2001 +From: Marc Zyngier <maz@kernel.org> +Date: Tue, 30 Mar 2021 16:11:41 +0100 +Subject: PCI/MSI: Let PCI host bridges declare their reliance on MSI domains + +There is a whole class of host bridges that cannot know whether +MSIs will be provided or not, as they rely on other blocks +to provide the MSI functionnality, using MSI domains. This is +the case for example on systems that use the ARM GIC architecture. + +Introduce a new attribute ('msi_domain') indicating that implicit +dependency, and use this property to set the NO_MSI flag when +no MSI domain is found at probe time. + +Link: https://lore.kernel.org/r/20210330151145.997953-11-maz@kernel.org +Signed-off-by: Marc Zyngier <maz@kernel.org> +Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> +Acked-by: Bjorn Helgaas <bhelgaas@google.com> +--- + drivers/pci/probe.c | 2 ++ + include/linux/pci.h | 1 + + 2 files changed, 3 insertions(+) + +--- a/drivers/pci/probe.c ++++ b/drivers/pci/probe.c +@@ -925,6 +925,8 @@ static int pci_register_host_bridge(stru + 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)) ++ bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI; + + if (!parent) + set_dev_node(bus->bridge, pcibus_to_node(bus)); +--- a/include/linux/pci.h ++++ b/include/linux/pci.h +@@ -547,6 +547,7 @@ struct pci_host_bridge { + unsigned int native_dpc:1; /* OS may use PCIe DPC */ + unsigned int preserve_config:1; /* Preserve FW resource setup */ + unsigned int size_windows:1; /* Enable root bus sizing */ ++ unsigned int msi_domain:1; /* Bridge wants MSI domain */ + + /* Resource alignment requirements */ + resource_size_t (*align_resource)(struct pci_dev *dev, |