[PATCHv6 06/17] LoongArch/mm: Align vmemmap to maximal folio size

Kiryl Shutsemau
2026-02-02T15:57:34Z

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_NR_PAGES.

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..f9416acb9156 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_NR_PAGES * sizeof(struct page))
+#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