In the intel iommu driver devices which only support 32bit DMA can't be
direct mapped. The implementation of this is weird. Currently we assign
it a direct mapped domain and then remove the domain later and replace
it with a domain of type IOMMU_DOMAIN_IDENTITY. We should just assign it
a domain of type IOMMU_DOMAIN_IDENTITY from the begging rather than
needlessly swapping domains.
Signed-off-by: Tom Murphy
---
drivers/iommu/intel-iommu.c | 88 +
1 file changed, 31 insertions(+), 57 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0c8d81f56a30..c1ea66467918 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3462,46 +3462,9 @@ static struct dmar_domain
*get_private_domain_for_dev(struct device *dev)
}
/* Check if the dev needs to go through non-identity map and unmap process.*/
-static bool iommu_need_mapping(struct device *dev)
+static bool iommu_no_mapping(struct device *dev)
{
- int ret;
-
- if (iommu_dummy(dev))
- return false;
-
- ret = identity_mapping(dev);
- if (ret) {
- u64 dma_mask = *dev->dma_mask;
-
- if (dev->coherent_dma_mask && dev->coherent_dma_mask < dma_mask)
- dma_mask = dev->coherent_dma_mask;
-
- if (dma_mask >= dma_direct_get_required_mask(dev))
- return false;
-
- /*
-* 32 bit DMA is removed from si_domain and fall back to
-* non-identity mapping.
-*/
- dmar_remove_one_dev_info(dev);
- ret = iommu_request_dma_domain_for_dev(dev);
- if (ret) {
- struct iommu_domain *domain;
- struct dmar_domain *dmar_domain;
-
- domain = iommu_get_domain_for_dev(dev);
- if (domain) {
- dmar_domain = to_dmar_domain(domain);
- dmar_domain->flags |= DOMAIN_FLAG_LOSE_CHILDREN;
- }
- dmar_remove_one_dev_info(dev);
- get_private_domain_for_dev(dev);
- }
-
- dev_info(dev, "32bit DMA uses non-identity mapping\n");
- }
-
- return true;
+ return iommu_dummy(dev) || identity_mapping(dev);
}
static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
@@ -3568,20 +3531,22 @@ static dma_addr_t intel_map_page(struct device *dev,
struct page *page,
enum dma_data_direction dir,
unsigned long attrs)
{
- if (iommu_need_mapping(dev))
- return __intel_map_single(dev, page_to_phys(page) + offset,
- size, dir, *dev->dma_mask);
- return dma_direct_map_page(dev, page, offset, size, dir, attrs);
+ if (iommu_no_mapping(dev))
+ return dma_direct_map_page(dev, page, offset, size, dir, attrs);
+
+ return __intel_map_single(dev, page_to_phys(page) + offset, size, dir,
+ *dev->dma_mask);
}
static dma_addr_t intel_map_resource(struct device *dev, phys_addr_t phys_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
- if (iommu_need_mapping(dev))
- return __intel_map_single(dev, phys_addr, size, dir,
- *dev->dma_mask);
- return dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
+ if (iommu_no_mapping(dev))
+ return dma_direct_map_resource(dev, phys_addr, size, dir,
+ attrs);
+
+ return __intel_map_single(dev, phys_addr, size, dir, *dev->dma_mask);
}
static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
@@ -3632,16 +3597,16 @@ static void intel_unmap_page(struct device *dev,
dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
- if (iommu_need_mapping(dev))
- intel_unmap(dev, dev_addr, size);
- else
+ if (iommu_no_mapping(dev))
dma_direct_unmap_page(dev, dev_addr, size, dir, attrs);
+ else
+ intel_unmap(dev, dev_addr, size);
}
static void intel_unmap_resource(struct device *dev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
- if (iommu_need_mapping(dev))
+ if (!iommu_no_mapping(dev))
intel_unmap(dev, dev_addr, size);
}
@@ -3652,7 +3617,7 @@ static void *intel_alloc_coherent(struct device *dev,
size_t size,
struct page *page = NULL;
int order;
- if (!iommu_need_mapping(dev))
+ if (iommu_no_mapping(dev))
return
