[PATCH for-5.10] swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single

[Christoph Hellwig <hch@xxxxxx>]

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@xxxxxx>
Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 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