From ec487d1a110abfffebdf116560db5c1d71b94cab Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 26 Jun 2008 21:27:58 +0200 Subject: [PATCH] x86, AMD IOMMU: add domain allocation and deallocation functions This patch adds the functions to allocate and free protection domains for the IOMMU. Signed-off-by: Joerg Roedel Cc: iommu@lists.linux-foundation.org Cc: bhavna.sarathy@amd.com Cc: Sebastian.Biemueller@amd.com Cc: robert.richter@amd.com Cc: joro@8bytes.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/amd_iommu.c | 147 ++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 69d8d024387e..c43d15dbc8fa 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -314,3 +314,150 @@ static void dma_ops_free_addresses(struct dma_ops_domain *dom, iommu_area_free(dom->bitmap, address, pages); } +static u16 domain_id_alloc(void) +{ + unsigned long flags; + int id; + + write_lock_irqsave(&amd_iommu_devtable_lock, flags); + id = find_first_zero_bit(amd_iommu_pd_alloc_bitmap, MAX_DOMAIN_ID); + BUG_ON(id == 0); + if (id > 0 && id < MAX_DOMAIN_ID) + __set_bit(id, amd_iommu_pd_alloc_bitmap); + else + id = 0; + write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + + return id; +} + +static void dma_ops_reserve_addresses(struct dma_ops_domain *dom, + unsigned long start_page, + unsigned int pages) +{ + unsigned int last_page = dom->aperture_size >> PAGE_SHIFT; + + if (start_page + pages > last_page) + pages = last_page - start_page; + + set_bit_string(dom->bitmap, start_page, pages); +} + +static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom) +{ + int i, j; + u64 *p1, *p2, *p3; + + p1 = dma_dom->domain.pt_root; + + if (!p1) + return; + + for (i = 0; i < 512; ++i) { + if (!IOMMU_PTE_PRESENT(p1[i])) + continue; + + p2 = IOMMU_PTE_PAGE(p1[i]); + for (j = 0; j < 512; ++i) { + if (!IOMMU_PTE_PRESENT(p2[j])) + continue; + p3 = IOMMU_PTE_PAGE(p2[j]); + free_page((unsigned long)p3); + } + + free_page((unsigned long)p2); + } + + free_page((unsigned long)p1); +} + +static void dma_ops_domain_free(struct dma_ops_domain *dom) +{ + if (!dom) + return; + + dma_ops_free_pagetable(dom); + + kfree(dom->pte_pages); + + kfree(dom->bitmap); + + kfree(dom); +} + +static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu, + unsigned order) +{ + struct dma_ops_domain *dma_dom; + unsigned i, num_pte_pages; + u64 *l2_pde; + u64 address; + + /* + * Currently the DMA aperture must be between 32 MB and 1GB in size + */ + if ((order < 25) || (order > 30)) + return NULL; + + dma_dom = kzalloc(sizeof(struct dma_ops_domain), GFP_KERNEL); + if (!dma_dom) + return NULL; + + spin_lock_init(&dma_dom->domain.lock); + + dma_dom->domain.id = domain_id_alloc(); + if (dma_dom->domain.id == 0) + goto free_dma_dom; + dma_dom->domain.mode = PAGE_MODE_3_LEVEL; + dma_dom->domain.pt_root = (void *)get_zeroed_page(GFP_KERNEL); + dma_dom->domain.priv = dma_dom; + if (!dma_dom->domain.pt_root) + goto free_dma_dom; + dma_dom->aperture_size = (1ULL << order); + dma_dom->bitmap = kzalloc(dma_dom->aperture_size / (PAGE_SIZE * 8), + GFP_KERNEL); + if (!dma_dom->bitmap) + goto free_dma_dom; + /* + * mark the first page as allocated so we never return 0 as + * a valid dma-address. So we can use 0 as error value + */ + dma_dom->bitmap[0] = 1; + dma_dom->next_bit = 0; + + if (iommu->exclusion_start && + iommu->exclusion_start < dma_dom->aperture_size) { + unsigned long startpage = iommu->exclusion_start >> PAGE_SHIFT; + int pages = to_pages(iommu->exclusion_start, + iommu->exclusion_length); + dma_ops_reserve_addresses(dma_dom, startpage, pages); + } + + num_pte_pages = dma_dom->aperture_size / (PAGE_SIZE * 512); + dma_dom->pte_pages = kzalloc(num_pte_pages * sizeof(void *), + GFP_KERNEL); + if (!dma_dom->pte_pages) + goto free_dma_dom; + + l2_pde = (u64 *)get_zeroed_page(GFP_KERNEL); + if (l2_pde == NULL) + goto free_dma_dom; + + dma_dom->domain.pt_root[0] = IOMMU_L2_PDE(virt_to_phys(l2_pde)); + + for (i = 0; i < num_pte_pages; ++i) { + dma_dom->pte_pages[i] = (u64 *)get_zeroed_page(GFP_KERNEL); + if (!dma_dom->pte_pages[i]) + goto free_dma_dom; + address = virt_to_phys(dma_dom->pte_pages[i]); + l2_pde[i] = IOMMU_L1_PDE(address); + } + + return dma_dom; + +free_dma_dom: + dma_ops_domain_free(dma_dom); + + return NULL; +} +