[PATCH v3 05/17] arm64: pgtable: use mmu gather to free p4d level page table

Qi Zheng
2024-12-23T09:44:07Z

Like other levels of page tables, also use mmu gather mechanism to free
p4d level page table.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
---
arch/arm64/include/asm/pgalloc.h | 1 -
arch/arm64/include/asm/tlb.h | 14 ++++++++++++++
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 2965f5a7e39e3..1b4509d3382c6 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -85,7 +85,6 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgdp, p4d_t *p4dp)
__pgd_populate(pgdp, __pa(p4dp), pgdval);
}

-#define __p4d_free_tlb(tlb, p4d, addr) p4d_free((tlb)->mm, p4d)
#else
static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t p4dp, pgdval_t prot)
{
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index a947c6e784ed2..445282cde9afb 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -111,4 +111,18 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp,
}
#endif

+#if CONFIG_PGTABLE_LEVELS > 4
+static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4dp,
+ unsigned long addr)
+{
+ struct ptdesc *ptdesc = virt_to_ptdesc(p4dp);
+
+ if (!pgtable_l5_enabled())
+ return;
+
+ pagetable_p4d_dtor(ptdesc);
+ tlb_remove_ptdesc(tlb, ptdesc);
+}
+#endif
+
#endif
--
2.20.1