diff options
Diffstat (limited to 'include/asm-generic/pgalloc.h')
| -rw-r--r-- | include/asm-generic/pgalloc.h | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h new file mode 100644 index 000000000..02932efad --- /dev/null +++ b/include/asm-generic/pgalloc.h @@ -0,0 +1,187 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_PGALLOC_H +#define __ASM_GENERIC_PGALLOC_H + +#ifdef CONFIG_MMU + +#define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO) +#define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT) + +/** + * __pte_alloc_one_kernel - allocate a page for PTE-level kernel page table + * @mm: the mm_struct of the current context + * + * This function is intended for architectures that need + * anything beyond simple page allocation. + * + * Return: pointer to the allocated memory or %NULL on error + */ +static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm) +{ + return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL); +} + +#ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL +/** + * pte_alloc_one_kernel - allocate a page for PTE-level kernel page table + * @mm: the mm_struct of the current context + * + * Return: pointer to the allocated memory or %NULL on error + */ +static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) +{ + return __pte_alloc_one_kernel(mm); +} +#endif + +/** + * pte_free_kernel - free PTE-level kernel page table page + * @mm: the mm_struct of the current context + * @pte: pointer to the memory containing the page table + */ +static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) +{ + free_page((unsigned long)pte); +} + +/** + * __pte_alloc_one - allocate a page for PTE-level user page table + * @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(). + * + * This function is intended for architectures that need + * anything beyond simple page allocation or must have custom GFP flags. + * + * Return: `struct page` initialized as page table or %NULL on error + */ +static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp) +{ + struct page *pte; + + pte = alloc_page(gfp); + if (!pte) + return NULL; + if (!pgtable_pte_page_ctor(pte)) { + __free_page(pte); + return NULL; + } + + return pte; +} + +#ifndef __HAVE_ARCH_PTE_ALLOC_ONE +/** + * 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(). + * + * Return: `struct page` initialized as page table or %NULL on error + */ +static inline pgtable_t pte_alloc_one(struct mm_struct *mm) +{ + return __pte_alloc_one(mm, GFP_PGTABLE_USER); +} +#endif + +/* + * Should really implement gc for free page table pages. This could be + * done with a reference count in struct page. + */ + +/** + * pte_free - free PTE-level user page table page + * @mm: the mm_struct of the current context + * @pte_page: the `struct page` representing the page table + */ +static inline void pte_free(struct mm_struct *mm, struct page *pte_page) +{ + pgtable_pte_page_dtor(pte_page); + __free_page(pte_page); +} + + +#if CONFIG_PGTABLE_LEVELS > 2 + +#ifndef __HAVE_ARCH_PMD_ALLOC_ONE +/** + * 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(). + * Allocations use %GFP_PGTABLE_USER in user context and + * %GFP_PGTABLE_KERNEL in kernel context. + * + * Return: pointer to the allocated memory or %NULL on error + */ +static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr) +{ + struct page *page; + gfp_t gfp = GFP_PGTABLE_USER; + + if (mm == &init_mm) + gfp = GFP_PGTABLE_KERNEL; + page = alloc_pages(gfp, 0); + if (!page) + return NULL; + if (!pgtable_pmd_page_ctor(page)) { + __free_pages(page, 0); + return NULL; + } + return (pmd_t *)page_address(page); +} +#endif + +#ifndef __HAVE_ARCH_PMD_FREE +static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) +{ + BUG_ON((unsigned long)pmd & (PAGE_SIZE-1)); + pgtable_pmd_page_dtor(virt_to_page(pmd)); + free_page((unsigned long)pmd); +} +#endif + +#endif /* CONFIG_PGTABLE_LEVELS > 2 */ + +#if CONFIG_PGTABLE_LEVELS > 3 + +#ifndef __HAVE_ARCH_PUD_ALLOC_ONE +/** + * pud_alloc_one - allocate a page for PUD-level page table + * @mm: the mm_struct of the current context + * + * Allocates a page using %GFP_PGTABLE_USER for user context and + * %GFP_PGTABLE_KERNEL for kernel context. + * + * Return: pointer to the allocated memory or %NULL on error + */ +static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr) +{ + gfp_t gfp = GFP_PGTABLE_USER; + + if (mm == &init_mm) + gfp = GFP_PGTABLE_KERNEL; + return (pud_t *)get_zeroed_page(gfp); +} +#endif + +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); +} + +#endif /* CONFIG_PGTABLE_LEVELS > 3 */ + +#ifndef __HAVE_ARCH_PGD_FREE +static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + free_page((unsigned long)pgd); +} +#endif + +#endif /* CONFIG_MMU */ + +#endif /* __ASM_GENERIC_PGALLOC_H */ |