From 147202aa772329a02c6e80bc2b7a6b8dd3deac0b Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 7 Jul 2009 19:43:20 +0100 Subject: [PATCH] intel-iommu: Speed up map routines by using cached domain ASAP We did before, in the end -- but it was at the bottom of a long stack of functions. Add an inline wrapper get_valid_domain_for_dev() which will use the cached one _first_ and only make the out-of-line call if it's not already set. This takes the average time taken for a 1-page intel_map_sg() from 5961 cycles to 4812 cycles on my Lenovo x200s test box -- a modest 20%. Signed-off-by: David Woodhouse --- drivers/pci/intel-iommu.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 360fb67a30d..c5f7c73cbb5 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -2455,8 +2455,7 @@ static struct iova *intel_alloc_iova(struct device *dev, return iova; } -static struct dmar_domain * -get_valid_domain_for_dev(struct pci_dev *pdev) +static struct dmar_domain *__get_valid_domain_for_dev(struct pci_dev *pdev) { struct dmar_domain *domain; int ret; @@ -2484,6 +2483,18 @@ get_valid_domain_for_dev(struct pci_dev *pdev) return domain; } +static inline struct dmar_domain *get_valid_domain_for_dev(struct pci_dev *dev) +{ + struct device_domain_info *info; + + /* No lock here, assumes no domain exit in normal case */ + info = dev->dev.archdata.iommu; + if (likely(info)) + return info->domain; + + return __get_valid_domain_for_dev(dev); +} + static int iommu_dummy(struct pci_dev *pdev) { return pdev->dev.archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO; -- 2.41.0