On 2020-11-04 23:14, Thomas Gleixner wrote:
[...]
TBH, that's butt ugly. So after staring long enough into the PCI code I
came up with a way to transport that information to the probe code.
That allows a particular device to say 'I can't do MSI' and at the same
time keeps the warning machinery intact which tells us that a
particular
host controller driver is broken.
Uncompiled and untested as usual :)
Thanks,
tglx
---
drivers/pci/controller/pcie-mediatek.c | 4 ++++
drivers/pci/probe.c | 3 +++
include/linux/pci.h | 1 +
3 files changed, 8 insertions(+)
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -143,6 +143,7 @@ struct mtk_pcie_port;
* struct mtk_pcie_soc - differentiate between host generations
* @need_fix_class_id: whether this host's class ID needed to be fixed
or not
* @need_fix_device_id: whether this host's device ID needed to be
fixed or not
+ * @no_msi: Bridge has no MSI support
* @device_id: device ID which this host need to be fixed
* @ops: pointer to configuration access functions
* @startup: pointer to controller setting functions
@@ -151,6 +152,7 @@ struct mtk_pcie_port;
struct mtk_pcie_soc {
bool need_fix_class_id;
bool need_fix_device_id;
+ bool no_msi;
unsigned int device_id;
struct pci_ops *ops;
int (*startup)(struct mtk_pcie_port *port);
@@ -1084,6 +1086,7 @@ static int mtk_pcie_probe(struct platfor
host->ops = pcie->soc->ops;
host->sysdata = pcie;
+ host->no_msi = pcie->soc->no_msi;
err = pci_host_probe(host);
if (err)
@@ -1173,6 +1176,7 @@ static const struct dev_pm_ops mtk_pcie_
};
static const struct mtk_pcie_soc mtk_pcie_soc_v1 = {
+ .no_msi = true,
.ops = &mtk_pcie_ops,
.startup = mtk_pcie_startup_port,
};
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -889,6 +889,9 @@ static int pci_register_host_bridge(stru
if (!bus)
return -ENOMEM;
+ if (bridge->no_msi)
+ bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+
bridge->bus = bus;
/* Temporarily move resources off the list */
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -545,6 +545,7 @@ 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,
If that's the direction of travel, we also need something like this
for configuration where the host bridge relies on an external MSI block
that uses MSI domains (boot-tested in a GICv3 guest).
M.
diff --git a/drivers/pci/controller/pci-host-common.c
b/drivers/pci/controller/pci-host-common.c
index 6ce34a1deecb..603f6fbbe68a 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/drivers/pci/controller/pci-host-common.c
@@ -77,6 +77,7 @@ int pci_host_common_probe(struct platform_device
*pdev)
bridge->sysdata = cfg;
bridge->ops = (struct pci_ops *)&ops->pci_ops;
+ bridge->msi_domain = true;
platform_set_drvdata(pdev, bridge);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 16fb150fbb8d..f421b2869bca 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -889,9 +889,6 @@ static int pci_register_host_bridge(struct
pci_host_bridge *bridge)
if (!bus)
return -ENOMEM;
- if (bridge->no_msi)
- bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
-
bridge->bus = bus;
/* Temporarily move resources off the list */
@@ -928,6 +925,9 @@ 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 ||
+ (bridge->msi_domain && !bus->dev.msi_domain))
+ 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 c2a0c1d471d6..81f72fd46e06 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -546,6 +546,7 @@ struct pci_host_bridge {
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 */
+ unsigned int msi_domain:1; /* Bridge wants MSI domain */
/* Resource alignment requirements */
resource_size_t (*align_resource)(struct pci_dev *dev,
--
Jazz is not dead. It just smells funny...
