Gitweb: http://git.kernel.org/linus/f3a0a52fff4dbfdea2dccc908d00c038481d888e
Commit: f3a0a52fff4dbfdea2dccc908d00c038481d888e
Parent: 3d7b0e4154b4963d6bd39991ec8eaa09caeb3994
Author: David Woodhouse <David.Woodhouse@intel.com>
AuthorDate: Tue Jun 30 03:40:07 2009 +0100
Committer: David Woodhouse <David.Woodhouse@intel.com>
CommitDate: Tue Jun 30 03:58:15 2009 +0100
intel-iommu: Performance improvement for dma_pte_free_pagetable()
As with other functions, batch the CPU data cache flushes and don't keep
recalculating PTE addresses.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---
drivers/pci/intel-iommu.c | 27 +++++++++++++++++----------
1 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 35bdd2a..ec7e032 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -797,7 +797,7 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
unsigned long last_pfn)
{
int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
- struct dma_pte *pte;
+ struct dma_pte *first_pte, *pte;
int total = agaw_to_level(domain->agaw);
int level;
unsigned long tmp;
@@ -805,25 +805,32 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
- /* we don't need lock here, nobody else touches the iova range */
+ /* We don't need lock here; nobody else touches the iova range */
level = 2;
while (level <= total) {
tmp = align_to_level(start_pfn, level);
- /* Only clear this pte/pmd if we're asked to clear its
- _whole_ range */
+ /* If we can't even clear one PTE at this level, we're done */
if (tmp + level_size(level) - 1 > last_pfn)
return;
while (tmp + level_size(level) - 1 <= last_pfn) {
- pte = dma_pfn_level_pte(domain, tmp, level);
- if (pte) {
- free_pgtable_page(
- phys_to_virt(dma_pte_addr(pte)));
+ first_pte = pte = dma_pfn_level_pte(domain, tmp, level);
+ if (!pte) {
+ tmp = align_to_level(tmp + 1, level + 1);
+ continue;
+ }
+ while (tmp + level_size(level) - 1 <= last_pfn &&
+ (unsigned long)pte >> VTD_PAGE_SHIFT ==
+ (unsigned long)first_pte >> VTD_PAGE_SHIFT) {
+ free_pgtable_page(phys_to_virt(dma_pte_addr(pte)));
dma_clear_pte(pte);
- domain_flush_cache(domain, pte, sizeof(*pte));
+ pte++;
+ tmp += level_size(level);
}
- tmp += level_size(level);
+ domain_flush_cache(domain, first_pte,
+ (void *)pte - (void *)first_pte);
+
}
level++;
}
--
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