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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>
This commit is contained in:
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
Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/iommu/intel/iommu.c
View File

@@ -737,7 +737,8 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
return NULL;
domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
pteval = virt_to_phys(tmp_page) | DMA_PTE_READ |
DMA_PTE_WRITE;
if (domain->use_first_level)
pteval |= DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;

19
drivers/iommu/intel/iommu.h
View File

@@ -953,25 +953,6 @@ static inline unsigned long lvl_to_nr_pages(unsigned int lvl)
return 1UL << min_t(int, (lvl - 1) * LEVEL_STRIDE, MAX_AGAW_PFN_WIDTH);
}
/* VT-d pages must always be _smaller_ than MM pages. Otherwise things
are never going to work. */
static inline unsigned long mm_to_dma_pfn_start(unsigned long mm_pfn)
{
return mm_pfn << (PAGE_SHIFT - VTD_PAGE_SHIFT);
}
static inline unsigned long mm_to_dma_pfn_end(unsigned long mm_pfn)
{
return ((mm_pfn + 1) << (PAGE_SHIFT - VTD_PAGE_SHIFT)) - 1;
}
static inline unsigned long page_to_dma_pfn(struct page *pg)
{
return mm_to_dma_pfn_start(page_to_pfn(pg));
}
static inline unsigned long virt_to_dma_pfn(void *p)
{
return page_to_dma_pfn(virt_to_page(p));
}
static inline void context_set_present(struct context_entry *context)
{
context->lo |= 1;