On Wed, Jan 08, 2025 at 02:57:21PM +0800, Qi Zheng wrote:
> Like other levels of page tables, also use mmu gather mechanism to free
> p4d level page table.
>
> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Originally-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Reviewed-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> ---
> 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);
> +}
Should we update p4d_free() to call the destructor, too? It looks like
it just does free_page() atm.
Will
