iommu/vt-d: Use virt_to_phys()

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If all the inlines are unwound virt_to_dma_pfn() is simply:
   return page_to_pfn(virt_to_page(p)) << (PAGE_SHIFT - VTD_PAGE_SHIFT);

Which can be re-arranged to:
   (page_to_pfn(virt_to_page(p)) << PAGE_SHIFT) >> VTD_PAGE_SHIFT

The only caller is:
   ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT)

re-arranged to:
   ((page_to_pfn(virt_to_page(tmp_page)) << PAGE_SHIFT) >> VTD_PAGE_SHIFT)
           << VTD_PAGE_SHIFT

Which simplifies to:
   page_to_pfn(virt_to_page(tmp_page)) << PAGE_SHIFT

That is the same as virt_to_phys(tmp_page), so just remove all of this.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/8-v3-e797f4dc6918+93057-iommu_pages_jgg@nvidia.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

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Jason Gunthorpe 2025-03-10 10:47:45 +08:00 • committed by Joerg Roedel

parent 9ce7603ad3

commit a8653e5cc2

2 changed files with 2 additions and 20 deletions

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3

drivers/iommu/intel/iommu.c

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19

drivers/iommu/intel/iommu.h

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