diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4859669f0ab..55721822282 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1546,6 +1546,41 @@ void pci_enable_ari(struct pci_dev *dev) } /** + * pci_enable_acs - enable ACS if hardware support it + * @dev: the PCI device + */ +void pci_enable_acs(struct pci_dev *dev) +{ + int pos; + u16 cap; + u16 ctrl; + + if (!dev->is_pcie) + return; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS); + if (!pos) + return; + + pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap); + pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl); + + /* Source Validation */ + ctrl |= (cap & PCI_ACS_SV); + + /* P2P Request Redirect */ + ctrl |= (cap & PCI_ACS_RR); + + /* P2P Completion Redirect */ + ctrl |= (cap & PCI_ACS_CR); + + /* Upstream Forwarding */ + ctrl |= (cap & PCI_ACS_UF); + + pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl); +} + +/** * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge * @dev: the PCI device * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD) |