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| author | Chris Wright <chrisw@sous-sol.org> | 2009-12-04 20:15:21 (GMT) |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2009-12-05 00:19:24 (GMT) |
| commit | 5d990b627537e59a3a2f039ff588a4750e9c1a6a (patch) | |
| tree | 8c0e723c3f9146da52b30c087a80fc417df2b41b /drivers/pci/pci.c | |
| parent | b26a34aa4792b3db2500b8a98cb7702765c1a92e (diff) | |
| download | linux-5d990b627537e59a3a2f039ff588a4750e9c1a6a.tar.xz | |
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 <allen.m.kay@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6af212c..cd9b375 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; |