From 5d990b627537e59a3a2f039ff588a4750e9c1a6a Mon Sep 17 00:00:00 2001 From: Chris Wright Date: Fri, 4 Dec 2009 12:15:21 -0800 Subject: PCI: add pci_request_acs Commit ae21ee65e8bc228416bbcc8a1da01c56a847a60c "PCI: acs p2p upsteram forwarding enabling" doesn't actually enable ACS. Add a function to pci core to allow an IOMMU to request that ACS be enabled. The existing mechanism of using iommu_found() in the pci core to know when ACS should be enabled doesn't actually work due to initialization order; iommu has only been detected not initialized. Have Intel and AMD IOMMUs request ACS, and Xen does as well during early init of dom0. Cc: Allen Kay Cc: David Woodhouse Cc: Jeremy Fitzhardinge Cc: Joerg Roedel Signed-off-by: Chris Wright Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6af212c509c..cd9b375f49d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1550,6 +1550,16 @@ void pci_enable_ari(struct pci_dev *dev) bridge->ari_enabled = 1; } +static int pci_acs_enable; + +/** + * pci_request_acs - ask for ACS to be enabled if supported + */ +void pci_request_acs(void) +{ + pci_acs_enable = 1; +} + /** * pci_enable_acs - enable ACS if hardware support it * @dev: the PCI device @@ -1560,6 +1570,9 @@ void pci_enable_acs(struct pci_dev *dev) u16 cap; u16 ctrl; + if (!pci_acs_enable) + return; + if (!pci_is_pcie(dev)) return; -- cgit v1.2.3