diff options
| author | Chris Wright | 2009-12-04 12:15:21 -0800 |
|---|---|---|
| committer | Jesse Barnes | 2009-12-04 16:19:24 -0800 |
| commit | 5d990b627537e59a3a2f039ff588a4750e9c1a6a (patch) | |
| tree | 8c0e723c3f9146da52b30c087a80fc417df2b41b /drivers/pci | |
| parent | b26a34aa4792b3db2500b8a98cb7702765c1a92e (diff) | |
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')
| -rw-r--r-- | drivers/pci/dmar.c | 5 | ||||
| -rw-r--r-- | drivers/pci/pci.c | 13 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 5 |
3 files changed, 18 insertions, 5 deletions
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index e01ca4d6b3e6..0e98f6b6f515 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -614,8 +614,11 @@ void __init detect_intel_iommu(void) #endif #ifdef CONFIG_DMAR if (ret && !no_iommu && !iommu_detected && !swiotlb && - !dmar_disabled) + !dmar_disabled) { iommu_detected = 1; + /* Make sure ACS will be enabled */ + pci_request_acs(); + } #endif } early_acpi_os_unmap_memory(dmar_tbl, dmar_tbl_size); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6af212c509c5..cd9b375f49d5 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; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 2fdffc02a308..98ffb2de22e9 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -10,9 +10,7 @@ #include <linux/module.h> #include <linux/cpumask.h> #include <linux/pci-aspm.h> -#include <linux/iommu.h> #include <acpi/acpi_hest.h> -#include <xen/xen.h> #include "pci.h" #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ @@ -1029,8 +1027,7 @@ static void pci_init_capabilities(struct pci_dev *dev) pci_iov_init(dev); /* Enable ACS P2P upstream forwarding */ - if (iommu_found() || xen_initial_domain()) - pci_enable_acs(dev); + pci_enable_acs(dev); } void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) |