# \[PATCH v16 10/13\] powerpc: mm: Add pud\_pfn() stub

- From: Andrew Donnellan \<hidden\>
- Date: 2025-08-13 06:28:06 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2025/08/3167654
- Thread: https://ratatoskr.run/linuxppc-dev/2025/08/3167646/t.md

```text
From: Rohan McLure <redacted>

The page table check feature requires that pud_pfn() be defined
on each consuming architecture. Since only 64-bit, Book3S platforms
allow for hugepages at this upper level, and since the calling code is
gated by a call to pud_user_accessible_page(), which will return zero,
include this stub as a BUILD_BUG().

Signed-off-by: Rohan McLure <redacted>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Donnellan <redacted>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
---
 arch/powerpc/include/asm/pgtable.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 93d77ad5a92f..0f73a9ade0ed 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -214,6 +214,15 @@ static inline bool arch_supports_memmap_on_memory(unsigned long vmemmap_size)
 
 #endif /* CONFIG_PPC64 */
 
+#ifndef pud_pfn
+#define pud_pfn pud_pfn
+static inline int pud_pfn(pud_t pud)
+{
+	BUILD_BUG();
+	return 0;
+}
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_PGTABLE_H */
-- 
2.50.1


```