From 71b390e9bec5121d25c45326ff0b0b96a143f9a8 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Wed, 1 Apr 2015 14:58:49 +0200 Subject: [PATCH] iommu/amd: Optimize iommu_unmap_page for new fetch_pte interface Now that fetch_pte returns the page-size of the pte, this function can be optimized a lot. Tested-by: Suravee Suthikulpanit Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 28 ++++++---------------------- 1 file changed, 6 insertions(+), 22 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 24ef9e600289..c9ee444d8209 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1428,8 +1428,8 @@ static unsigned long iommu_unmap_page(struct protection_domain *dom, unsigned long bus_addr, unsigned long page_size) { - unsigned long long unmap_size, unmapped; - unsigned long pte_pgsize; + unsigned long long unmapped; + unsigned long unmap_size; u64 *pte; BUG_ON(!is_power_of_2(page_size)); @@ -1438,28 +1438,12 @@ static unsigned long iommu_unmap_page(struct protection_domain *dom, while (unmapped < page_size) { - pte = fetch_pte(dom, bus_addr, &pte_pgsize); + pte = fetch_pte(dom, bus_addr, &unmap_size); - if (!pte) { - /* - * No PTE for this address - * move forward in 4kb steps - */ - unmap_size = PAGE_SIZE; - } else if (PM_PTE_LEVEL(*pte) == 0) { - /* 4kb PTE found for this address */ - unmap_size = PAGE_SIZE; - *pte = 0ULL; - } else { - int count, i; + if (pte) { + int i, count; - /* Large PTE found which maps this address */ - unmap_size = PTE_PAGE_SIZE(*pte); - - /* Only unmap from the first pte in the page */ - if ((unmap_size - 1) & bus_addr) - break; - count = PAGE_SIZE_PTE_COUNT(unmap_size); + count = PAGE_SIZE_PTE_COUNT(unmap_size); for (i = 0; i < count; i++) pte[i] = 0ULL; }