From: Omer Peleg <[email protected]> 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 <[email protected]> [[email protected]: fixed locking issues] Signed-off-by: Godfrey van der Linden <[email protected]> [[email protected]: rebased and reworded the commit message] Signed-off-by: Adam Morrison <[email protected]> --- drivers/iommu/intel-iommu.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index c52a3ef..b371455 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -392,6 +392,7 @@ struct dmar_domain { * to VT-d spec, section 9.3 */ struct list_head devices; /* all devices' list */ + bool has_iotlb_device; struct iova_domain iovad; /* iova's that belong to this domain */ struct dma_pte *pgd; /* virtual address */ @@ -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; -- 1.9.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
