[PATCH 08/13] PCI: MSI: Let PCI host bridges declare their lack of MSI handling
From: Marc Zyngier <maz@kernel.org>
Date: 2021-02-25 15:14:45
Also in:
linux-arm-kernel, linux-hyperv, linux-mediatek, linux-renesas-soc, linux-tegra, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
From: Thomas Gleixner <redacted> Some PCI host bridges cannot deal with MSIs at all. This has the unfortunate effect of triggering ugly warnings when an end-point driver requests MSIs. Instead, let the bridge advertise such lack of MSIs, so that it can be flagged correctly by the core code. Signed-off-by: Thomas Gleixner <redacted> [maz: commit message] Signed-off-by: Marc Zyngier <maz@kernel.org> --- drivers/pci/probe.c | 2 ++ include/linux/pci.h | 1 + 2 files changed, 3 insertions(+)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index fb04fc81a8bd..146bd85c037e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c@@ -925,6 +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->no_msi) + bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI; if (!parent) set_dev_node(bus->bridge, pcibus_to_node(bus));
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 105ef1a5191e..9db3abf9fd90 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h@@ -550,6 +550,7 @@ 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 no_msi:1; /* Bridge has no MSI support */ /* Resource alignment requirements */ resource_size_t (*align_resource)(struct pci_dev *dev,
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2.29.2