| From | Jiri Slaby <> | Subject | [PATCH 3.12 098/111] iommu/amd: Optimize iommu_unmap_page for new fetch_pte interface | Date | Wed, 10 Jun 2015 17:27:27 +0200 |
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From: Joerg Roedel <jroedel@suse.de>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 71b390e9bec5121d25c45326ff0b0b96a143f9a8 upstream.
Now that fetch_pte returns the page-size of the pte, this function can be optimized a lot.
Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- drivers/iommu/amd_iommu.c | 32 ++++++++------------------------ 1 file changed, 8 insertions(+), 24 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 976cf15744a9..8f6344df7c49 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1479,8 +1479,8 @@ 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)); @@ -1489,28 +1489,12 @@ static unsigned long iommu_unmap_page(struct protection_domain *dom, while (unmapped < page_size) { - pte = fetch_pte(dom, bus_addr, &pte_pgsize); - - 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; - - /* 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); + pte = fetch_pte(dom, bus_addr, &unmap_size); + + if (pte) { + int i, count; + + count = PAGE_SIZE_PTE_COUNT(unmap_size); for (i = 0; i < count; i++) pte[i] = 0ULL; } -- 2.4.2
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