xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

PCI: Treat "external-facing" devices themselves as internal

Browse Source 
"External-facing" devices are internal devices that expose PCIe hierarchies
such as Thunderbolt outside the platform [1].  Previously these internal
devices were marked as "untrusted" the same as devices downstream from
them.

Use the ACPI or DT information to identify external-facing devices, but
only mark the devices *downstream* from them as "untrusted" [2].  The
external-facing device itself is no longer marked as untrusted.

[1] https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#identifying-externally-exposed-pcie-root-ports
[2] https://lore.kernel.org/linux-pci/20200610230906.GA1528594@bjorn-Precision-5520/
Link: https://lore.kernel.org/r/20200707224604.3737893-3-rajatja@google.com
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Rajat Jain
2020-07-07 15:46:03 -07:00
committed by Bjorn Helgaas
parent 52fbf5bdee
commit 99b50be9d8
5 changed files with 15 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/pci/pci-acpi.c
View File

@@ -1213,7 +1213,7 @@ static void pci_acpi_optimize_delay(struct pci_dev *pdev,
ACPI_FREE(obj);
}
static void pci_acpi_set_untrusted(struct pci_dev *dev)
static void pci_acpi_set_external_facing(struct pci_dev *dev)
{
u8 val;
@@ -1224,11 +1224,10 @@ static void pci_acpi_set_untrusted(struct pci_dev *dev)
/*
* These root ports expose PCIe (including DMA) outside of the
* system so make sure we treat them and everything behind as
* untrusted.
* system. Everything downstream from them is external.
*/
if (val)
dev->untrusted = 1;
dev->external_facing = 1;
}
static void pci_acpi_setup(struct device *dev)
@@ -1240,7 +1239,7 @@ static void pci_acpi_setup(struct device *dev)
return;
pci_acpi_optimize_delay(pci_dev, adev->handle);
pci_acpi_set_untrusted(pci_dev);
pci_acpi_set_external_facing(pci_dev);
pci_acpi_add_edr_notifier(pci_dev);
pci_acpi_add_pm_notifier(adev, pci_dev);