From 5fba4af4456b5d3f982d4ac1c879d16b36aaa0fb Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Thu, 11 Jul 2019 20:57:49 -0700 Subject: asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel] Most architectures have identical or very similar implementation of pte_alloc_one_kernel(), pte_alloc_one(), pte_free_kernel() and pte_free(). Add a generic implementation that can be reused across architectures and enable its use on x86. The generic implementation uses GFP_KERNEL | __GFP_ZERO for the kernel page tables and GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT for the user page tables. The "base" functions for PTE allocation, namely __pte_alloc_one_kernel() and __pte_alloc_one() are intended for the architectures that require additional actions after actual memory allocation or must use non-default GFP flags. x86 is switched to use generic pte_alloc_one_kernel(), pte_free_kernel() and pte_free(). x86 still implements pte_alloc_one() to allow run-time control of GFP flags required for "userpte" command line option. Link: http://lkml.kernel.org/r/1557296232-15361-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport Cc: Albert Ou Cc: Anshuman Khandual Cc: Anton Ivanov Cc: Arnd Bergmann Cc: Catalin Marinas Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Guan Xuetao Cc: Guo Ren Cc: Guo Ren Cc: Helge Deller Cc: Ley Foon Tan Cc: Matthew Wilcox Cc: Matt Turner Cc: Michael Ellerman Cc: Michal Hocko Cc: Palmer Dabbelt Cc: Paul Burton Cc: Ralf Baechle Cc: Richard Kuo Cc: Richard Weinberger Cc: Russell King Cc: Sam Creasey Cc: Vincent Chen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/pgalloc.h | 107 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 103 insertions(+), 4 deletions(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h index 948714c1535a..8476175c07e7 100644 --- a/include/asm-generic/pgalloc.h +++ b/include/asm-generic/pgalloc.h @@ -1,13 +1,112 @@ /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __ASM_GENERIC_PGALLOC_H #define __ASM_GENERIC_PGALLOC_H -/* - * an empty file is enough for a nommu architecture - */ + #ifdef CONFIG_MMU -#error need to implement an architecture specific asm/pgalloc.h + +#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_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_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_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_page_dtor(pte_page); + __free_page(pte_page); +} + +#else /* CONFIG_MMU */ + +/* This is enough for a nommu architecture */ #define check_pgt_cache() do { } while (0) +#endif /* CONFIG_MMU */ + #endif /* __ASM_GENERIC_PGALLOC_H */ -- cgit v1.2.3-55-g7522