From 5dda4dc570ac41e3bd73ef871c500aeb7005c6b0 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Fri, 18 Jan 2013 15:12:19 +0530 Subject: ARC: Page Table Management Signed-off-by: Vineet Gupta --- arch/arc/include/asm/pgalloc.h | 134 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 arch/arc/include/asm/pgalloc.h (limited to 'arch/arc/include/asm/pgalloc.h') diff --git a/arch/arc/include/asm/pgalloc.h b/arch/arc/include/asm/pgalloc.h new file mode 100644 index 00000000000..36a9f20c21a --- /dev/null +++ b/arch/arc/include/asm/pgalloc.h @@ -0,0 +1,134 @@ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * vineetg: June 2011 + * -"/proc/meminfo | grep PageTables" kept on increasing + * Recently added pgtable dtor was not getting called. + * + * vineetg: May 2011 + * -Variable pg-sz means that Page Tables could be variable sized themselves + * So calculate it based on addr traversal split [pgd-bits:pte-bits:xxx] + * -Page Table size capped to max 1 to save memory - hence verified. + * -Since these deal with constants, gcc compile-time optimizes them. + * + * vineetg: Nov 2010 + * -Added pgtable ctor/dtor used for pgtable mem accounting + * + * vineetg: April 2010 + * -Switched pgtable_t from being struct page * to unsigned long + * =Needed so that Page Table allocator (pte_alloc_one) is not forced to + * to deal with struct page. Thay way in future we can make it allocate + * multiple PG Tbls in one Page Frame + * =sweet side effect is avoiding calls to ugly page_address( ) from the + * pg-tlb allocator sub-sys (pte_alloc_one, ptr_free, pmd_populate + * + * Amit Bhor, Sameer Dhavale: Codito Technologies 2004 + */ + +#ifndef _ASM_ARC_PGALLOC_H +#define _ASM_ARC_PGALLOC_H + +#include +#include + +static inline void +pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte) +{ + pmd_set(pmd, pte); +} + +static inline void +pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t ptep) +{ + pmd_set(pmd, (pte_t *) ptep); +} + +static inline int __get_order_pgd(void) +{ + return get_order(PTRS_PER_PGD * 4); +} + +static inline pgd_t *pgd_alloc(struct mm_struct *mm) +{ + int num, num2; + pgd_t *ret = (pgd_t *) __get_free_pages(GFP_KERNEL, __get_order_pgd()); + + if (ret) { + num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE; + memzero(ret, num * sizeof(pgd_t)); + + num2 = VMALLOC_SIZE / PGDIR_SIZE; + memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t)); + + memzero(ret + num + num2, + (PTRS_PER_PGD - num - num2) * sizeof(pgd_t)); + + } + return ret; +} + +static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + free_pages((unsigned long)pgd, __get_order_pgd()); +} + + +/* + * With software-only page-tables, addr-split for traversal is tweakable and + * that directly governs how big tables would be at each level. + * Further, the MMU page size is configurable. + * Thus we need to programatically assert the size constraint + * All of this is const math, allowing gcc to do constant folding/propagation. + */ + +static inline int __get_order_pte(void) +{ + return get_order(PTRS_PER_PTE * 4); +} + +static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, + unsigned long address) +{ + pte_t *pte; + + pte = (pte_t *) __get_free_pages(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO, + __get_order_pte()); + + return pte; +} + +static inline pgtable_t +pte_alloc_one(struct mm_struct *mm, unsigned long address) +{ + pgtable_t pte_pg; + + pte_pg = __get_free_pages(GFP_KERNEL | __GFP_REPEAT, __get_order_pte()); + if (pte_pg) { + memzero((void *)pte_pg, PTRS_PER_PTE * 4); + pgtable_page_ctor(virt_to_page(pte_pg)); + } + + return pte_pg; +} + +static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) +{ + free_pages((unsigned long)pte, __get_order_pte()); /* takes phy addr */ +} + +static inline void pte_free(struct mm_struct *mm, pgtable_t ptep) +{ + pgtable_page_dtor(virt_to_page(ptep)); + free_pages(ptep, __get_order_pte()); +} + +#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte) + +#define check_pgt_cache() do { } while (0) +#define pmd_pgtable(pmd) pmd_page_vaddr(pmd) + +#endif /* _ASM_ARC_PGALLOC_H */ -- cgit v1.2.3