[PATCHv7 06/18] LoongArch/mm: Align vmemmap to maximal folio size

Kiryl Shutsemau (Meta)
2026-02-27T19:30:43Z

From: Kiryl Shutsemau <kas@kernel.org>

The upcoming change to the HugeTLB vmemmap optimization (HVO) requires
struct pages of the head page to be naturally aligned with regard to the
folio size.

Align vmemmap to MAX_FOLIO_VMEMMAP_ALIGN.

Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
---
arch/loongarch/include/asm/pgtable.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index c33b3bcb733e..ea6c09eed2e7 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -113,7 +113,8 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits) / 2) - PMD_SIZE - VMEMMAP_SIZE - KFENCE_AREA_SIZE)
#endif

-#define vmemmap ((struct page *)((VMALLOC_END + PMD_SIZE) & PMD_MASK))
+#define VMEMMAP_ALIGN max(PMD_SIZE, MAX_FOLIO_VMEMMAP_ALIGN)
+#define vmemmap ((struct page *)(ALIGN(VMALLOC_END, VMEMMAP_ALIGN)))
#define VMEMMAP_END ((unsigned long)vmemmap + VMEMMAP_SIZE - 1)

#define KFENCE_AREA_START (VMEMMAP_END + 1)
--
2.51.2