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

[Mike Rapoport <rppt@xxxxxxxxxx>]

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@xxxxxxxxx>

Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

> ---
>  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.