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authorDavid Woodhouse <David.Woodhouse@intel.com>2014-03-19 16:07:49 +0000
committerDavid Woodhouse <David.Woodhouse@intel.com>2014-03-19 17:21:32 +0000
commit5cf0a76fa2179d246fc0375d733bdccffd59382b (patch)
tree252606f6807877d15a936dd94325742cf8021a8d /drivers/iommu
parent75f05569d0e51f6332a291c82abbeb7c8262e32d (diff)
downloadop-kernel-dev-5cf0a76fa2179d246fc0375d733bdccffd59382b.zip
op-kernel-dev-5cf0a76fa2179d246fc0375d733bdccffd59382b.tar.gz
iommu/vt-d: Clean up size handling for intel_iommu_unmap()
We have this horrid API where iommu_unmap() can unmap more than it's asked to, if the IOVA in question happens to be mapped with a large page. Instead of propagating this nonsense to the point where we end up returning the page order from dma_pte_clear_range(), let's just do it once and adjust the 'size' parameter accordingly. Augment pfn_to_dma_pte() to return the level at which the PTE was found, which will also be useful later if we end up changing the API for iommu_iova_to_phys() to behave the same way as is being discussed upstream. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/intel-iommu.c37
1 files changed, 25 insertions, 12 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 484d669..6472bf1 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -784,7 +784,7 @@ out:
}
static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
- unsigned long pfn, int target_level)
+ unsigned long pfn, int *target_level)
{
int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
struct dma_pte *parent, *pte = NULL;
@@ -799,14 +799,14 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
parent = domain->pgd;
- while (level > 0) {
+ while (1) {
void *tmp_page;
offset = pfn_level_offset(pfn, level);
pte = &parent[offset];
- if (!target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte)))
+ if (!*target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte)))
break;
- if (level == target_level)
+ if (level == *target_level)
break;
if (!dma_pte_present(pte)) {
@@ -827,10 +827,16 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
domain_flush_cache(domain, pte, sizeof(*pte));
}
}
+ if (level == 1)
+ break;
+
parent = phys_to_virt(dma_pte_addr(pte));
level--;
}
+ if (!*target_level)
+ *target_level = level;
+
return pte;
}
@@ -868,7 +874,7 @@ static struct dma_pte *dma_pfn_level_pte(struct dmar_domain *domain,
}
/* clear last level pte, a tlb flush should be followed */
-static int dma_pte_clear_range(struct dmar_domain *domain,
+static void dma_pte_clear_range(struct dmar_domain *domain,
unsigned long start_pfn,
unsigned long last_pfn)
{
@@ -898,8 +904,6 @@ static int dma_pte_clear_range(struct dmar_domain *domain,
(void *)pte - (void *)first_pte);
} while (start_pfn && start_pfn <= last_pfn);
-
- return min_t(int, (large_page - 1) * 9, MAX_AGAW_PFN_WIDTH);
}
static void dma_pte_free_level(struct dmar_domain *domain, int level,
@@ -1832,7 +1836,7 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
if (!pte) {
largepage_lvl = hardware_largepage_caps(domain, iov_pfn, phys_pfn, sg_res);
- first_pte = pte = pfn_to_dma_pte(domain, iov_pfn, largepage_lvl);
+ first_pte = pte = pfn_to_dma_pte(domain, iov_pfn, &largepage_lvl);
if (!pte)
return -ENOMEM;
/* It is large page*/
@@ -4099,15 +4103,23 @@ static size_t intel_iommu_unmap(struct iommu_domain *domain,
unsigned long iova, size_t size)
{
struct dmar_domain *dmar_domain = domain->priv;
- int order;
+ int level = 0;
+
+ /* Cope with horrid API which requires us to unmap more than the
+ size argument if it happens to be a large-page mapping. */
+ if (!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level))
+ BUG();
+
+ if (size < VTD_PAGE_SIZE << level_to_offset_bits(level))
+ size = VTD_PAGE_SIZE << level_to_offset_bits(level);
- order = dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,
+ dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,
(iova + size - 1) >> VTD_PAGE_SHIFT);
if (dmar_domain->max_addr == iova + size)
dmar_domain->max_addr = iova;
- return PAGE_SIZE << order;
+ return size;
}
static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
@@ -4115,9 +4127,10 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
{
struct dmar_domain *dmar_domain = domain->priv;
struct dma_pte *pte;
+ int level = 0;
u64 phys = 0;
- pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, 0);
+ pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
if (pte)
phys = dma_pte_addr(pte);
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