diff options
author | Mike Rapoport | 2019-07-11 20:57:49 -0700 |
---|---|---|
committer | Linus Torvalds | 2019-07-12 11:05:45 -0700 |
commit | 5fba4af4456b5d3f982d4ac1c879d16b36aaa0fb (patch) | |
tree | 0e4431ff013d419e295eec2a53fbcd419100adbf /include/asm-generic | |
parent | 790c73690c2bbecb3f6f8becbdb11ddc9bcff8cc (diff) |
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 <rppt@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-generic')
-rw-r--r-- | include/asm-generic/pgalloc.h | 107 |
1 files changed, 103 insertions, 4 deletions
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 */ |