On Mon, Jun 12, 2023 at 02:04:08PM -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>
> ---
> include/asm-generic/pgalloc.h | 62 +++++++++++++++++++++--------------
> 1 file changed, 37 insertions(+), 25 deletions(-)
>
> diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
> index a7cf825befae..3fd6ce79e654 100644
> --- a/include/asm-generic/pgalloc.h
> +++ b/include/asm-generic/pgalloc.h
> @@ -18,7 +18,11 @@
> */
> static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
> {
> - return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
> + struct ptdesc *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL, 0);
> +
> + if (!ptdesc)
> + return NULL;
> + return ptdesc_address(ptdesc);
> }
>
> #ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
> @@ -41,7 +45,7 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> */
> static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> {
> - free_page((unsigned long)pte);
> + pagetable_free(virt_to_ptdesc(pte));
> }
>
> /**
> @@ -49,7 +53,7 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> * @mm: the mm_struct of the current context
> * @gfp: GFP flags to use for the allocation
> *
> - * Allocates a page and runs the pgtable_pte_page_ctor().
> + * Allocates a ptdesc and runs the pagetable_pte_ctor().
Allocates memory for page table and ptdesc
> *
> * This function is intended for architectures that need
> * anything beyond simple page allocation or must have custom GFP flags.
The Return: description here should be fixed up
> @@ -58,17 +62,17 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> */
> static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
> {
> - struct page *pte;
> + struct ptdesc *ptdesc;
>
> - pte = alloc_page(gfp);
> - if (!pte)
> + ptdesc = pagetable_alloc(gfp, 0);
> + if (!ptdesc)
> return NULL;
> - if (!pgtable_pte_page_ctor(pte)) {
> - __free_page(pte);
> + if (!pagetable_pte_ctor(ptdesc)) {
> + pagetable_free(ptdesc);
> return NULL;
> }
>
> - return pte;
> + return ptdesc_page(ptdesc);
> }
>
> #ifndef __HAVE_ARCH_PTE_ALLOC_ONE
> @@ -76,7 +80,7 @@ static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
> * pte_alloc_one - allocate a page for PTE-level user page table
> * @mm: the mm_struct of the current context
> *
> - * Allocates a page and runs the pgtable_pte_page_ctor().
> + * Allocates a ptdesc and runs the pagetable_pte_ctor().
Allocates memory for page table and ptdesc
> *
> * Return: `struct page` initialized as page table or %NULL on error
Return: ptdesc ...
> */
> @@ -98,8 +102,10 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
> */
> static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
> {
> - pgtable_pte_page_dtor(pte_page);
> - __free_page(pte_page);
> + struct ptdesc *ptdesc = page_ptdesc(pte_page);
> +
> + pagetable_pte_dtor(ptdesc);
> + pagetable_free(ptdesc);
> }
>
>
> @@ -110,7 +116,7 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
> * pmd_alloc_one - allocate a page for PMD-level page table
> * @mm: the mm_struct of the current context
> *
> - * Allocates a page and runs the pgtable_pmd_page_ctor().
> + * Allocates a ptdesc and runs the pagetable_pmd_ctor().
Allocate memory for page table and ptdesc
> * Allocations use %GFP_PGTABLE_USER in user context and
> * %GFP_PGTABLE_KERNEL in kernel context.
> *
> @@ -118,28 +124,30 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
> */
> static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
> {
> - struct page *page;
> + struct ptdesc *ptdesc;
> gfp_t gfp = GFP_PGTABLE_USER;
>
> if (mm == &init_mm)
> gfp = GFP_PGTABLE_KERNEL;
> - page = alloc_page(gfp);
> - if (!page)
> + ptdesc = pagetable_alloc(gfp, 0);
> + if (!ptdesc)
> return NULL;
> - if (!pgtable_pmd_page_ctor(page)) {
> - __free_page(page);
> + if (!pagetable_pmd_ctor(ptdesc)) {
> + pagetable_free(ptdesc);
> return NULL;
> }
> - return (pmd_t *)page_address(page);
> + return ptdesc_address(ptdesc);
> }
> #endif
>
> #ifndef __HAVE_ARCH_PMD_FREE
> static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
> {
> + struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
> +
> BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
> - pgtable_pmd_page_dtor(virt_to_page(pmd));
> - free_page((unsigned long)pmd);
> + pagetable_pmd_dtor(ptdesc);
> + pagetable_free(ptdesc);
> }
> #endif
>
> @@ -149,11 +157,15 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
>
> static inline pud_t *__pud_alloc_one(struct mm_struct *mm, unsigned long addr)
> {
> - gfp_t gfp = GFP_PGTABLE_USER;
> + gfp_t gfp = GFP_PGTABLE_USER | __GFP_ZERO;
GFP_PGTABLE_USER already contains __GFP_ZERO
> + struct ptdesc *ptdesc;
>
> if (mm == &init_mm)
> gfp = GFP_PGTABLE_KERNEL;
> - return (pud_t *)get_zeroed_page(gfp);
> + ptdesc = pagetable_alloc(gfp, 0);
> + if (!ptdesc)
> + return NULL;
> + return ptdesc_address(ptdesc);
> }
>
> #ifndef __HAVE_ARCH_PUD_ALLOC_ONE
> @@ -175,7 +187,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
> static inline void __pud_free(struct mm_struct *mm, pud_t *pud)
> {
> BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
> - free_page((unsigned long)pud);
> + pagetable_free(virt_to_ptdesc(pud));
> }
>
> #ifndef __HAVE_ARCH_PUD_FREE
> @@ -190,7 +202,7 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
> #ifndef __HAVE_ARCH_PGD_FREE
> static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
> {
> - free_page((unsigned long)pgd);
> + pagetable_free(virt_to_ptdesc(pgd));
> }
> #endif
>
> --
> 2.40.1
>
>
--
Sincerely yours,
Mike.
