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| author | David Woodhouse <David.Woodhouse@intel.com> | 2009-06-30 04:40:07 +0200 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-06-30 04:58:15 +0200 |
| commit | f3a0a52fff4dbfdea2dccc908d00c038481d888e (patch) | |
| tree | 956261c5e5a00c115eed6741d1ae10fd71d4a411 | |
| parent | intel-iommu: Don't free too much in dma_pte_free_pagetable() (diff) | |
| download | linux-f3a0a52fff4dbfdea2dccc908d00c038481d888e.tar.xz linux-f3a0a52fff4dbfdea2dccc908d00c038481d888e.zip | |
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>
| -rw-r--r-- | 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 35bdd2a06caa..ec7e032d5ab5 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++; } |