[Patch Part3 V4 10/21] iommu/vt-d: Simplify intel_unmap_sg() and kill duplicated code

Jiang Liu
2014-07-11T06:17:31Z

Introduce intel_unmap() to reduce duplicated code in intel_unmap_sg()
and intel_unmap_page().

Also let dma_pte_free_pagetable() to call dma_pte_clear_range() directly,
so caller only needs to call dma_pte_free_pagetable().

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 70 ++++++++++++-------------------------------
1 file changed, 19 insertions(+), 51 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0ba078bc0f32..0852b7021e4a 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -984,6 +984,8 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
BUG_ON(start_pfn > last_pfn);

+ dma_pte_clear_range(domain, start_pfn, last_pfn);
+
/* We don't need lock here; nobody else touches the iova range */
dma_pte_free_level(domain, agaw_to_level(domain->agaw),
domain->pgd, 0, start_pfn, last_pfn);
@@ -2011,12 +2013,14 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
/* It is large page*/
if (largepage_lvl > 1) {
pteval |= DMA_PTE_LARGE_PAGE;
- /* Ensure that old small page tables are removed to make room
- for superpage, if they exist. */
- dma_pte_clear_range(domain, iov_pfn,
- iov_pfn + lvl_to_nr_pages(largepage_lvl) - 1);
+ lvl_pages = lvl_to_nr_pages(largepage_lvl);
+ /*
+ * Ensure that old small page tables are
+ * removed to make room for superpage,
+ * if they exist.
+ */
dma_pte_free_pagetable(domain, iov_pfn,
- iov_pfn + lvl_to_nr_pages(largepage_lvl) - 1);
+ iov_pfn + lvl_pages - 1);
} else {
pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE;
}
@@ -3148,9 +3152,7 @@ static void add_unmap(struct dmar_domain *dom, struct iova *iova, struct page *f
spin_unlock_irqrestore(&async_umap_flush_lock, flags);
}

-static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
- size_t size, enum dma_data_direction dir,
- struct dma_attrs *attrs)
+static void intel_unmap(struct device *dev, dma_addr_t dev_addr)
{
struct dmar_domain *domain;
unsigned long start_pfn, last_pfn;
@@ -3194,6 +3196,13 @@ static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
}
}

+static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ intel_unmap(dev, dev_addr);
+}
+
static void *intel_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
@@ -3250,7 +3259,7 @@ static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
size = PAGE_ALIGN(size);
order = get_order(size);

- intel_unmap_page(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);
+ intel_unmap(dev, dma_handle);
if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
__free_pages(page, order);
}
@@ -3259,43 +3268,7 @@ static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- struct dmar_domain *domain;
- unsigned long start_pfn, last_pfn;
- struct iova *iova;
- struct intel_iommu *iommu;
- struct page *freelist;
-
- if (iommu_no_mapping(dev))
- return;
-
- domain = find_domain(dev);
- BUG_ON(!domain);
-
- iommu = domain_get_iommu(domain);
-
- iova = find_iova(&domain->iovad, IOVA_PFN(sglist[0].dma_address));
- if (WARN_ONCE(!iova, "Driver unmaps unmatched sglist at PFN %llx\n",
- (unsigned long long)sglist[0].dma_address))
- return;
-
- start_pfn = mm_to_dma_pfn(iova->pfn_lo);
- last_pfn = mm_to_dma_pfn(iova->pfn_hi + 1) - 1;
-
- freelist = domain_unmap(domain, start_pfn, last_pfn);
-
- if (intel_iommu_strict) {
- iommu_flush_iotlb_psi(iommu, domain->id, start_pfn,
- last_pfn - start_pfn + 1, !freelist, 0);
- /* free iova */
- __free_iova(&domain->iovad, iova);
- dma_free_pagelist(freelist);
- } else {
- add_unmap(domain, iova, freelist);
- /*
- * queue up the release of the unmap to save the 1/6th of the
- * cpu used up by the iotlb flush operation...
- */
- }
+ intel_unmap(dev, sglist[0].dma_address);
}

static int intel_nontranslate_map_sg(struct device *hddev,
@@ -3359,13 +3332,8 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele

ret = domain_sg_mapping(domain, start_vpfn, sglist, size, prot);
if (unlikely(ret)) {
- /* clear the page */
- dma_pte_clear_range(domain, start_vpfn,
- start_vpfn + size - 1);
- /* free page tables */
dma_pte_free_pagetable(domain, start_vpfn,
start_vpfn + size - 1);
- /* free iova */
__free_iova(&domain->iovad, iova);
return 0;
}
--
1.7.10.4