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authorKeshavamurthy, Anil S <anil.s.keshavamurthy@intel.com>2007-10-22 03:41:46 +0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-22 19:13:18 +0400
commit994a65e25df85abc465cfee495557200e8205f9e (patch)
tree2b6676898cccc03a356a67a3173fdb50bb25abb6 /drivers/pci/search.c
parent10e5247f40f3bf7508a0ed2848c9cae37bddf4bc (diff)
downloadlinux-994a65e25df85abc465cfee495557200e8205f9e.tar.xz
Intel IOMMU: PCI generic helper function
When devices are under a p2p bridge, upstream transactions get replaced by the device id of the bridge as it owns the PCIE transaction. Hence its necessary to setup translations on behalf of the bridge as well. Due to this limitation all devices under a p2p share the same domain in a DMAR. We just cache the type of device, if its a native PCIe device or not for later use. [akpm@linux-foundation.org: BUG_ON -> WARN_ON+recover] Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ashok Raj <ashok.raj@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Christoph Lameter <clameter@sgi.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/pci/search.c')
-rw-r--r--drivers/pci/search.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index c6e79d01ce3d..b001b5922e33 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -14,6 +14,40 @@
#include "pci.h"
DECLARE_RWSEM(pci_bus_sem);
+/*
+ * find the upstream PCIE-to-PCI bridge of a PCI device
+ * if the device is PCIE, return NULL
+ * if the device isn't connected to a PCIE bridge (that is its parent is a
+ * legacy PCI bridge and the bridge is directly connected to bus 0), return its
+ * parent
+ */
+struct pci_dev *
+pci_find_upstream_pcie_bridge(struct pci_dev *pdev)
+{
+ struct pci_dev *tmp = NULL;
+
+ if (pdev->is_pcie)
+ return NULL;
+ while (1) {
+ if (!pdev->bus->self)
+ break;
+ pdev = pdev->bus->self;
+ /* a p2p bridge */
+ if (!pdev->is_pcie) {
+ tmp = pdev;
+ continue;
+ }
+ /* PCI device should connect to a PCIE bridge */
+ if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) {
+ /* Busted hardware? */
+ WARN_ON_ONCE(1);
+ return NULL;
+ }
+ return pdev;
+ }
+
+ return tmp;
+}
static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
{