Re: [PATCH v4 24/34] loongarch: Convert various functions to use ptdescs

[Mike Rapoport <rppt@kernel.org>]

On Mon, Jun 12, 2023 at 02:04:13PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/loongarch/include/asm/pgalloc.h | 27 +++++++++++++++------------
>  arch/loongarch/mm/pgtable.c          |  7 ++++---
>  2 files changed, 19 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
> index af1d1e4a6965..70bb3bdd201e 100644
> --- a/arch/loongarch/include/asm/pgalloc.h
> +++ b/arch/loongarch/include/asm/pgalloc.h
> @@ -45,9 +45,9 @@ extern void pagetable_init(void);
>  extern pgd_t *pgd_alloc(struct mm_struct *mm);
>  
>  #define __pte_free_tlb(tlb, pte, address)			\
> -do {							\
> -	pgtable_pte_page_dtor(pte);			\
> -	tlb_remove_page((tlb), pte);			\
> +do {								\
> +	pagetable_pte_dtor(page_ptdesc(pte));			\
> +	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
>  } while (0)
>  
>  #ifndef __PAGETABLE_PMD_FOLDED
> @@ -55,18 +55,18 @@ do {							\
>  static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	pmd_t *pmd;
> -	struct page *pg;
> +	struct ptdesc *ptdesc;
>  
> -	pg = alloc_page(GFP_KERNEL_ACCOUNT);
> -	if (!pg)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, 0);
> +	if (!ptdesc)
>  		return NULL;
>  
> -	if (!pgtable_pmd_page_ctor(pg)) {
> -		__free_page(pg);
> +	if (!pagetable_pmd_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
>  
> -	pmd = (pmd_t *)page_address(pg);
> +	pmd = ptdesc_address(ptdesc);
>  	pmd_init(pmd);
>  	return pmd;
>  }
> @@ -80,10 +80,13 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
>  static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	pud_t *pud;
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
>  
> -	pud = (pud_t *) __get_free_page(GFP_KERNEL);
> -	if (pud)
> -		pud_init(pud);
> +	if (!ptdesc)
> +		return NULL;
> +	pud = ptdesc_address(ptdesc);
> +
> +	pud_init(pud);
>  	return pud;
>  }
>  
> diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c
> index 36a6dc0148ae..cdba10ffc0df 100644
> --- a/arch/loongarch/mm/pgtable.c
> +++ b/arch/loongarch/mm/pgtable.c
> @@ -11,10 +11,11 @@
>  
>  pgd_t *pgd_alloc(struct mm_struct *mm)
>  {
> -	pgd_t *ret, *init;
> +	pgd_t *init, *ret = NULL;
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
>  
> -	ret = (pgd_t *) __get_free_page(GFP_KERNEL);
> -	if (ret) {
> +	if (ptdesc) {
> +		ret = (pgd_t *)ptdesc_address(ptdesc);
>  		init = pgd_offset(&init_mm, 0UL);
>  		pgd_init(ret);
>  		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.