aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/backport-5.15/821-v5.13-let-pci-host-bridges-declar-their-reliance-on-msi-domains.patch
diff options
context:
space:
mode:
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.patch44
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,