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authorYu Zhao <yu.zhao@intel.com>2008-10-14 14:02:53 +0800
committerJesse Barnes <jbarnes@virtuousgeek.org>2008-10-20 10:54:32 -0700
commit58c3a727cb73b75a9104d295f096cca12959a5a5 (patch)
tree70f1fe31f1ec12021777b6c6c49167356a864749 /drivers/pci/pci.c
parent201de56eb22f1ff3f36804bc70cbff220b50f067 (diff)
downloadop-kernel-dev-58c3a727cb73b75a9104d295f096cca12959a5a5.zip
op-kernel-dev-58c3a727cb73b75a9104d295f096cca12959a5a5.tar.gz
PCI: support PCIe ARI capability
This patch adds support for PCI Express Alternative Routing-ID Interpretation (ARI) capability. The ARI capability extends the Function Number field of the PCI Express Endpoint by reusing the Device Number which is otherwise hardwired to 0. With ARI, an Endpoint can have up to 256 functions. Signed-off-by: Yu Zhao <yu.zhao@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 553ca66..4db261e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1299,6 +1299,38 @@ void pci_pm_init(struct pci_dev *dev)
}
}
+/**
+ * pci_enable_ari - enable ARI forwarding if hardware support it
+ * @dev: the PCI device
+ */
+void pci_enable_ari(struct pci_dev *dev)
+{
+ int pos;
+ u32 cap;
+ u16 ctrl;
+
+ if (!dev->is_pcie)
+ return;
+
+ if (dev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
+ dev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
+ return;
+
+ pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
+ if (!pos)
+ return;
+
+ pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap);
+ if (!(cap & PCI_EXP_DEVCAP2_ARI))
+ return;
+
+ pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl);
+ ctrl |= PCI_EXP_DEVCTL2_ARI;
+ pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl);
+
+ dev->ari_enabled = 1;
+}
+
int
pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge)
{
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