device: Add a disabling PCIe device bus master function
A function pci_dev_disable_bus_master() is created. This function
can be used to disable Thunderbolt PCIe root ports, bridges and
devices for Vt-d based security platform at end of boot service.
BUG=None
TEST=Verified PCIe device bus master enable bit is cleared.
Signed-off-by: John Zhao <john.zhao@intel.com>
Change-Id: Ie92a15bf2c66fdc311098acb81019d4fb7f68313
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41042
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
diff --git a/src/device/pci_device.c b/src/device/pci_device.c
index f83520e..032e15c 100644
--- a/src/device/pci_device.c
+++ b/src/device/pci_device.c
@@ -1643,4 +1643,9 @@
#endif
}
}
+
+void pci_dev_disable_bus_master(const struct device *dev)
+{
+ pci_update_config16(dev, PCI_COMMAND, ~PCI_COMMAND_MASTER, 0x0);
+}
#endif