[Intel-gfx] [PATCH v2 05/10] iommu/vt-d: Always enable PASID/PRI PCI capabilities before ATS
David Woodhouse
dwmw2 at infradead.org
Tue Oct 13 14:34:27 PDT 2015
The behaviour if you enable PASID support after ATS is undefined. So we
have to enable it first, even if we don't know whether we'll need it.
This is safe enough; unless we set up a context that permits it, the device
can't actually *do* anything with it.
Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
drivers/iommu/Kconfig | 1 +
drivers/iommu/intel-iommu.c | 96 ++++++++++++++++++++++++++++++++-------------
2 files changed, 70 insertions(+), 27 deletions(-)
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index e3b2c2e..8d23f5e 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -138,6 +138,7 @@ config INTEL_IOMMU
config INTEL_IOMMU_SVM
bool "Support for Shared Virtual Memory with Intel IOMMU"
depends on INTEL_IOMMU && X86
+ select PCI_PASID
help
Shared Virtual Memory (SVM) provides a facility for devices
to access DMA resources through process address space by
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 4a81523b..3b901ca 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -418,10 +418,13 @@ struct device_domain_info {
struct list_head global; /* link to global list */
u8 bus; /* PCI bus number */
u8 devfn; /* PCI devfn number */
- struct {
- u8 enabled:1;
- u8 qdep;
- } ats; /* ATS state */
+ u8 pasid_supported:3;
+ u8 pasid_enabled:1;
+ u8 pri_supported:1;
+ u8 pri_enabled:1;
+ u8 ats_supported:1;
+ u8 ats_enabled:1;
+ u8 ats_qdep;
struct device *dev; /* it's NULL for PCIe-to-PCI bridge */
struct intel_iommu *iommu; /* IOMMU used by this device */
struct dmar_domain *domain; /* pointer to domain */
@@ -1426,9 +1429,6 @@ iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
assert_spin_locked(&device_domain_lock);
- if (!ecap_dev_iotlb_support(iommu->ecap))
- return NULL;
-
if (!iommu->qi)
return NULL;
@@ -1444,16 +1444,27 @@ iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
pdev = to_pci_dev(info->dev);
- if (!pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS))
- return NULL;
+ if (ecs_enabled(iommu)) {
+ if (pasid_enabled(iommu)) {
+ int features = pci_pasid_features(pdev);
+ if (features >= 0)
+ info->pasid_supported = features | 1;
+ }
+
+ if (ecap_prs(iommu->ecap) && pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI))
+ info->pri_supported = 1;
+ }
- if (!dmar_find_matched_atsr_unit(pdev)) {
- if (intel_iommu_pasid28 && IS_GFX_DEVICE(pdev) &&
- pdev->vendor == 0x8086) {
+ if (ecap_dev_iotlb_support(iommu->ecap) &&
+ pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS)) {
+ if (dmar_find_matched_atsr_unit(pdev))
+ info->ats_supported = 1;
+ else if (intel_iommu_pasid28 && IS_GFX_DEVICE(pdev) &&
+ pdev->vendor == 0x8086) {
pr_warn("BIOS denies ATSR capability for %s; assuming it lies\n",
dev_name(info->dev));
- } else
- return NULL;
+ info->ats_supported = 1;
+ }
}
return info;
}
@@ -1466,20 +1477,48 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
return;
pdev = to_pci_dev(info->dev);
- if (pci_enable_ats(pdev, VTD_PAGE_SHIFT))
- return;
- info->ats.enabled = 1;
- info->ats.qdep = pci_ats_queue_depth(pdev);
+#ifdef CONFIG_INTEL_IOMMU_SVM
+ /* The PCIe spec, in its wisdom, declares that the behaviour of
+ the device if you enable PASID support after ATS support is
+ undefined. So always enable PASID support on devices which
+ have it, even if we can't yet know if we're ever going to
+ use it. */
+ if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1))
+ info->pasid_enabled = 1;
+
+ if (info->pri_supported && !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32))
+ info->pri_enabled = 1;
+#endif
+ if (info->ats_supported && !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
+ info->ats_enabled = 1;
+ info->ats_qdep = pci_ats_queue_depth(pdev);
+ }
}
static void iommu_disable_dev_iotlb(struct device_domain_info *info)
{
- if (!info->ats.enabled)
+ struct pci_dev *pdev;
+
+ if (dev_is_pci(info->dev))
return;
- pci_disable_ats(to_pci_dev(info->dev));
- info->ats.enabled = 0;
+ pdev = to_pci_dev(info->dev);
+
+ if (info->ats_enabled) {
+ pci_disable_ats(pdev);
+ info->ats_enabled = 0;
+ }
+#ifdef CONFIG_INTEL_IOMMU_SVM
+ if (info->pri_enabled) {
+ pci_disable_pri(pdev);
+ info->pri_enabled = 0;
+ }
+ if (info->pasid_enabled) {
+ pci_disable_pasid(pdev);
+ info->pasid_enabled = 0;
+ }
+#endif
}
static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
@@ -1491,11 +1530,11 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry(info, &domain->devices, link) {
- if (!info->ats.enabled)
+ if (!info->ats_enabled)
continue;
sid = info->bus << 8 | info->devfn;
- qdep = info->ats.qdep;
+ qdep = info->ats_qdep;
qi_flush_dev_iotlb(info->iommu, sid, qdep, addr, mask);
}
spin_unlock_irqrestore(&device_domain_lock, flags);
@@ -1957,8 +1996,10 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
}
info = iommu_support_dev_iotlb(domain, iommu, bus, devfn);
- translation = info ? CONTEXT_TT_DEV_IOTLB :
- CONTEXT_TT_MULTI_LEVEL;
+ if (info && info->ats_supported)
+ translation = CONTEXT_TT_DEV_IOTLB;
+ else
+ translation = CONTEXT_TT_MULTI_LEVEL;
context_set_address_root(context, virt_to_phys(pgd));
context_set_address_width(context, iommu->agaw);
@@ -2296,8 +2337,9 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
info->bus = bus;
info->devfn = devfn;
- info->ats.enabled = 0;
- info->ats.qdep = 0;
+ info->ats_supported = info->pasid_supported = info->pri_supported = 0;
+ info->ats_enabled = info->pasid_enabled = info->pri_enabled = 0;
+ info->ats_qdep = 0;
info->dev = dev;
info->domain = domain;
info->iommu = iommu;
--
2.4.3
--
David Woodhouse Open Source Technology Centre
David.Woodhouse at intel.com Intel Corporation
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