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| author | Khalid Aziz | 2012-04-27 21:00:33 +0200 |
|---|---|---|
| committer | Bjorn Helgaas | 2012-05-04 19:07:18 +0200 |
| commit | b566a22c23327f18ce941ffad0ca907e50a53d41 (patch) | |
| tree | ce675ff2f56a88778ea051f779868ffb9d746160 | |
| parent | PCI: work around IvyBridge internal graphics FLR erratum (diff) | |
| download | kernel-qcow2-linux-b566a22c23327f18ce941ffad0ca907e50a53d41.tar.gz kernel-qcow2-linux-b566a22c23327f18ce941ffad0ca907e50a53d41.tar.xz kernel-qcow2-linux-b566a22c23327f18ce941ffad0ca907e50a53d41.zip | |
PCI: disable Bus Master on PCI device shutdown
Disable Bus Master bit on the device in pci_device_shutdown() to ensure PCI
devices do not continue to DMA data after shutdown. This can cause memory
corruption in case of a kexec where the current kernel shuts down and
transfers control to a new kernel while a PCI device continues to DMA to
memory that does not belong to it any more in the new kernel.
I have tested this code on two laptops, two workstations and a 16-socket
server. kexec worked correctly on all of them.
Signed-off-by: Khalid Aziz <khalid.aziz@hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
| -rw-r--r-- | drivers/pci/pci-driver.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 6b54b23b990b..bf0cee629b60 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -421,6 +421,12 @@ static void pci_device_shutdown(struct device *dev) pci_msix_shutdown(pci_dev); /* + * Turn off Bus Master bit on the device to tell it to not + * continue to do DMA + */ + pci_disable_device(pci_dev); + + /* * Devices may be enabled to wake up by runtime PM, but they need not * be supposed to wake up the system from its "power off" state (e.g. * ACPI S5). Therefore disable wakeup for all devices that aren't |