From: Joerg Roedel <[email protected]> This allows to build up the page-tables without holding any locks. As a consequence it removes the need to pre-populate dma_ops page-tables.
Signed-off-by: Joerg Roedel <[email protected]> --- drivers/iommu/amd_iommu.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 4c926da..ecdd3f7 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1206,11 +1206,21 @@ static u64 *alloc_pte(struct protection_domain *domain, end_lvl = PAGE_SIZE_LEVEL(page_size); while (level > end_lvl) { - if (!IOMMU_PTE_PRESENT(*pte)) { + u64 __pte, __npte; + + __pte = *pte; + + if (!IOMMU_PTE_PRESENT(__pte)) { page = (u64 *)get_zeroed_page(gfp); if (!page) return NULL; - *pte = PM_LEVEL_PDE(level, virt_to_phys(page)); + + __npte = PM_LEVEL_PDE(level, virt_to_phys(page)); + + if (cmpxchg64(pte, __pte, __npte)) { + free_page((unsigned long)page); + continue; + } } /* No level skipping support yet */ @@ -1607,7 +1617,7 @@ static unsigned long dma_ops_alloc_addresses(struct device *dev, address = dma_ops_area_alloc(dev, dom, pages, align_mask, dma_mask); - if (address == -1 && alloc_new_range(dom, true, GFP_ATOMIC)) + if (address == -1 && alloc_new_range(dom, false, GFP_ATOMIC)) break; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
