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 <David.Woodhouse@intel.com>
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 360fb67..c5f7c73 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2455,8 +2455,7 @@
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 @@
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;