Mailing List Archive

The tbl_dma_addr argument is used to check the DMA boundary for the
allocations, and thus needs to be a dma_addr_t. swiotlb-xen instead
passed a physical address, which could lead to incorrect results for
strange offsets. Fix this by removing the parameter entirely and hard
code the DMA address for io_tlb_start instead.

Fixes: 91ffe4ad534a ("swiotlb-xen: introduce phys_to_dma/dma_to_phys translations")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
drivers/iommu/intel/iommu.c | 5 ++---
drivers/xen/swiotlb-xen.c | 3 +--
include/linux/swiotlb.h | 10 +++-------
kernel/dma/swiotlb.c | 16 ++++++----------
4 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 8651f6d4dfa032..6b560e6f193096 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3815,9 +3815,8 @@ bounce_map_single(struct device *dev, phys_addr_t paddr, size_t size,
* page aligned, we don't need to use a bounce page.
*/
if (!IS_ALIGNED(paddr | size, VTD_PAGE_SIZE)) {
- tlb_addr = swiotlb_tbl_map_single(dev,
- phys_to_dma_unencrypted(dev, io_tlb_start),
- paddr, size, aligned_size, dir, attrs);
+ tlb_addr = swiotlb_tbl_map_single(dev, paddr, size,
+ aligned_size, dir, attrs);
if (tlb_addr == DMA_MAPPING_ERROR) {
goto swiotlb_error;
} else {
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 71ce1b7a23d1cc..2b385c1b4a99cb 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -395,8 +395,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
*/
trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);

- map = swiotlb_tbl_map_single(dev, virt_to_phys(xen_io_tlb_start),
- phys, size, size, dir, attrs);
+ map = swiotlb_tbl_map_single(dev, phys, size, size, dir, attrs);
if (map == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 513913ff748626..3bb72266a75a1d 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -45,13 +45,9 @@ enum dma_sync_target {
SYNC_FOR_DEVICE = 1,
};

-extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
- dma_addr_t tbl_dma_addr,
- phys_addr_t phys,
- size_t mapping_size,
- size_t alloc_size,
- enum dma_data_direction dir,
- unsigned long attrs);
+phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys,
+ size_t mapping_size, size_t alloc_size,
+ enum dma_data_direction dir, unsigned long attrs);

extern void swiotlb_tbl_unmap_single(struct device *hwdev,
phys_addr_t tlb_addr,
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index b4eea0abc3f002..92e2f54f24c01b 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -441,14 +441,11 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr,
}
}

-phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
- dma_addr_t tbl_dma_addr,
- phys_addr_t orig_addr,
- size_t mapping_size,
- size_t alloc_size,
- enum dma_data_direction dir,
- unsigned long attrs)
+phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr,
+ size_t mapping_size, size_t alloc_size,
+ enum dma_data_direction dir, unsigned long attrs)
{
+ dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, io_tlb_start);
unsigned long flags;
phys_addr_t tlb_addr;
unsigned int nslots, stride, index, wrap;
@@ -667,9 +664,8 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size,
swiotlb_force);

- swiotlb_addr = swiotlb_tbl_map_single(dev,
- phys_to_dma_unencrypted(dev, io_tlb_start),
- paddr, size, size, dir, attrs);
+ swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, dir,
+ attrs);
if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;

--
2.28.0