Re: [PATCH v2 08/23] iommu/vtd: Use virt_to_phys()
From: Baolu Lu <baolu.lu@linux.intel.com>
Date: 2025-02-15 08:54:24
Also in:
asahi, linux-iommu, linux-patches, linux-riscv, linux-rockchip, linux-samsung-soc, linux-sunxi, linux-tegra
On 2/15/25 01:07, Jason Gunthorpe wrote:
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.
Signed-off-by: Jason Gunthorpe<jgg@nvidia.com>Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>