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authorOmer Peleg <omer@cs.technion.ac.il>2016-04-20 19:03:35 +0300
committerDavid Woodhouse <David.Woodhouse@intel.com>2016-04-20 15:06:15 -0400
commit0824c5920b16fe11034f3b5d2d48456d282d83f9 (patch)
tree0334d21ae66afbf95e56a0d9e08f673ae3dc0ac5 /drivers/iommu
parent769530e4ba4898748a293592f0920275b40cbb93 (diff)
downloadop-kernel-dev-0824c5920b16fe11034f3b5d2d48456d282d83f9.zip
op-kernel-dev-0824c5920b16fe11034f3b5d2d48456d282d83f9.tar.gz
iommu/vt-d: avoid dev iotlb logic for domains with no dev iotlbs
This patch avoids taking the device_domain_lock in iommu_flush_dev_iotlb() for domains with no dev iotlb devices. Signed-off-by: Omer Peleg <omer@cs.technion.ac.il> [gvdl@google.com: fixed locking issues] Signed-off-by: Godfrey van der Linden <gvdl@google.com> [mad@cs.technion.ac.il: rebased and reworded the commit message] Signed-off-by: Adam Morrison <mad@cs.technion.ac.il> Reviewed-by: Shaohua Li <shli@fb.com> Reviewed-by: Ben Serebrin <serebrin@google.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/intel-iommu.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 63b8c02..d100583 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -391,6 +391,7 @@ struct dmar_domain {
* domain ids are 16 bit wide according
* to VT-d spec, section 9.3 */
+ bool has_iotlb_device;
struct list_head devices; /* all devices' list */
struct iova_domain iovad; /* iova's that belong to this domain */
@@ -1464,10 +1465,35 @@ iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
return NULL;
}
+static void domain_update_iotlb(struct dmar_domain *domain)
+{
+ struct device_domain_info *info;
+ bool has_iotlb_device = false;
+
+ assert_spin_locked(&device_domain_lock);
+
+ list_for_each_entry(info, &domain->devices, link) {
+ struct pci_dev *pdev;
+
+ if (!info->dev || !dev_is_pci(info->dev))
+ continue;
+
+ pdev = to_pci_dev(info->dev);
+ if (pdev->ats_enabled) {
+ has_iotlb_device = true;
+ break;
+ }
+ }
+
+ domain->has_iotlb_device = has_iotlb_device;
+}
+
static void iommu_enable_dev_iotlb(struct device_domain_info *info)
{
struct pci_dev *pdev;
+ assert_spin_locked(&device_domain_lock);
+
if (!info || !dev_is_pci(info->dev))
return;
@@ -1487,6 +1513,7 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
#endif
if (info->ats_supported && !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
info->ats_enabled = 1;
+ domain_update_iotlb(info->domain);
info->ats_qdep = pci_ats_queue_depth(pdev);
}
}
@@ -1495,6 +1522,8 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info)
{
struct pci_dev *pdev;
+ assert_spin_locked(&device_domain_lock);
+
if (!dev_is_pci(info->dev))
return;
@@ -1503,6 +1532,7 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info)
if (info->ats_enabled) {
pci_disable_ats(pdev);
info->ats_enabled = 0;
+ domain_update_iotlb(info->domain);
}
#ifdef CONFIG_INTEL_IOMMU_SVM
if (info->pri_enabled) {
@@ -1523,6 +1553,9 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
unsigned long flags;
struct device_domain_info *info;
+ if (!domain->has_iotlb_device)
+ return;
+
spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry(info, &domain->devices, link) {
if (!info->ats_enabled)
@@ -1740,6 +1773,7 @@ static struct dmar_domain *alloc_domain(int flags)
memset(domain, 0, sizeof(*domain));
domain->nid = -1;
domain->flags = flags;
+ domain->has_iotlb_device = false;
INIT_LIST_HEAD(&domain->devices);
return domain;
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