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authorKeshavamurthy, Anil S <anil.s.keshavamurthy@intel.com>2007-10-21 16:41:46 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-22 08:13:18 -0700
commit994a65e25df85abc465cfee495557200e8205f9e (patch)
tree2b6676898cccc03a356a67a3173fdb50bb25abb6 /drivers/pci
parent10e5247f40f3bf7508a0ed2848c9cae37bddf4bc (diff)
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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')
-rw-r--r--drivers/pci/pci.h1
-rw-r--r--drivers/pci/probe.c14
-rw-r--r--drivers/pci/search.c34
3 files changed, 49 insertions, 0 deletions
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6fda33d..fc87e14 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -90,3 +90,4 @@ pci_match_one_device(const struct pci_device_id *id, const struct pci_dev *dev)
return NULL;
}
+struct pci_dev *pci_find_upstream_pcie_bridge(struct pci_dev *pdev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5db6b66..463a5a9 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -837,6 +837,19 @@ static void pci_release_dev(struct device *dev)
kfree(pci_dev);
}
+static void set_pcie_port_type(struct pci_dev *pdev)
+{
+ int pos;
+ u16 reg16;
+
+ pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
+ if (!pos)
+ return;
+ pdev->is_pcie = 1;
+ pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
+ pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;
+}
+
/**
* pci_cfg_space_size - get the configuration space size of the PCI device.
* @dev: PCI device
@@ -951,6 +964,7 @@ pci_scan_device(struct pci_bus *bus, int devfn)
dev->device = (l >> 16) & 0xffff;
dev->cfg_size = pci_cfg_space_size(dev);
dev->error_state = pci_channel_io_normal;
+ set_pcie_port_type(dev);
/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
set this higher, assuming the system even supports it. */
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index c6e79d0..b001b59 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)
{