[PATCH 0/2] iommu: debug-pagealloc: Remove pfn_valid() usage

Mostafa Saleh
2026-01-19T14:22:52Z

This is a small fix for the new config IOMMU_DEBUG_PAGEALLOC based
on the discussion:
https://lore.kernel.org/linux-iommu/CAFgf54pBAUm3ao-UJksiuGKtvv4wzRyFq_uKwLe0H1ettO4DLQ@mail.gmail.com/

Where it was concluded that pfn_valid() is not enough to validate
physical addresses before access to page_ext.

The first patch introduces a new function in page_ext that takes a
physical address as an argument, and the second patch uses it instead
of calling pfn_valid() and phys_to_page()

Benchmarks with the new implementation can be found in:
https://lore.kernel.org/linux-iommu/20260114164322.787125-1-smostafa@google.com/

This series applies to iommu/core tree.

Mostafa Saleh (2):
mm/page_ext: Add page_ext_get_phys()
iommu: debug-pagealloc: Use page_ext_get_phys()

drivers/iommu/iommu-debug-pagealloc.c | 31 ++++++++++++---------------
include/linux/page_ext.h | 6 ++++++
mm/page_ext.c | 23 ++++++++++++++++++++
3 files changed, 43 insertions(+), 17 deletions(-)

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2.52.0.457.g6b5491de43-goog