1 /* 2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * vineetg: June 2011 9 * -"/proc/meminfo | grep PageTables" kept on increasing 10 * Recently added pgtable dtor was not getting called. 11 * 12 * vineetg: May 2011 13 * -Variable pg-sz means that Page Tables could be variable sized themselves 14 * So calculate it based on addr traversal split [pgd-bits:pte-bits:xxx] 15 * -Page Table size capped to max 1 to save memory - hence verified. 16 * -Since these deal with constants, gcc compile-time optimizes them. 17 * 18 * vineetg: Nov 2010 19 * -Added pgtable ctor/dtor used for pgtable mem accounting 20 * 21 * vineetg: April 2010 22 * -Switched pgtable_t from being struct page * to unsigned long 23 * =Needed so that Page Table allocator (pte_alloc_one) is not forced to 24 * to deal with struct page. Thay way in future we can make it allocate 25 * multiple PG Tbls in one Page Frame 26 * =sweet side effect is avoiding calls to ugly page_address( ) from the 27 * pg-tlb allocator sub-sys (pte_alloc_one, ptr_free, pmd_populate 28 * 29 * Amit Bhor, Sameer Dhavale: Codito Technologies 2004 30 */ 31 32 #ifndef _ASM_ARC_PGALLOC_H 33 #define _ASM_ARC_PGALLOC_H 34 35 #include <linux/mm.h> 36 #include <linux/log2.h> 37 38 static inline void 39 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte) 40 { 41 pmd_set(pmd, pte); 42 } 43 44 static inline void 45 pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t ptep) 46 { 47 pmd_set(pmd, (pte_t *) ptep); 48 } 49 50 static inline int __get_order_pgd(void) 51 { 52 return get_order(PTRS_PER_PGD * sizeof(pgd_t)); 53 } 54 55 static inline pgd_t *pgd_alloc(struct mm_struct *mm) 56 { 57 int num, num2; 58 pgd_t *ret = (pgd_t *) __get_free_pages(GFP_KERNEL, __get_order_pgd()); 59 60 if (ret) { 61 num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE; 62 memzero(ret, num * sizeof(pgd_t)); 63 64 num2 = VMALLOC_SIZE / PGDIR_SIZE; 65 memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t)); 66 67 memzero(ret + num + num2, 68 (PTRS_PER_PGD - num - num2) * sizeof(pgd_t)); 69 70 } 71 return ret; 72 } 73 74 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) 75 { 76 free_pages((unsigned long)pgd, __get_order_pgd()); 77 } 78 79 80 /* 81 * With software-only page-tables, addr-split for traversal is tweakable and 82 * that directly governs how big tables would be at each level. 83 * Further, the MMU page size is configurable. 84 * Thus we need to programatically assert the size constraint 85 * All of this is const math, allowing gcc to do constant folding/propagation. 86 */ 87 88 static inline int __get_order_pte(void) 89 { 90 return get_order(PTRS_PER_PTE * sizeof(pte_t)); 91 } 92 93 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, 94 unsigned long address) 95 { 96 pte_t *pte; 97 98 pte = (pte_t *) __get_free_pages(GFP_KERNEL | __GFP_ZERO, 99 __get_order_pte()); 100 101 return pte; 102 } 103 104 static inline pgtable_t 105 pte_alloc_one(struct mm_struct *mm, unsigned long address) 106 { 107 pgtable_t pte_pg; 108 struct page *page; 109 110 pte_pg = (pgtable_t)__get_free_pages(GFP_KERNEL, __get_order_pte()); 111 if (!pte_pg) 112 return 0; 113 memzero((void *)pte_pg, PTRS_PER_PTE * sizeof(pte_t)); 114 page = virt_to_page(pte_pg); 115 if (!pgtable_page_ctor(page)) { 116 __free_page(page); 117 return 0; 118 } 119 120 return pte_pg; 121 } 122 123 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) 124 { 125 free_pages((unsigned long)pte, __get_order_pte()); /* takes phy addr */ 126 } 127 128 static inline void pte_free(struct mm_struct *mm, pgtable_t ptep) 129 { 130 pgtable_page_dtor(virt_to_page(ptep)); 131 free_pages((unsigned long)ptep, __get_order_pte()); 132 } 133 134 #define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte) 135 136 #define check_pgt_cache() do { } while (0) 137 #define pmd_pgtable(pmd) ((pgtable_t) pmd_page_vaddr(pmd)) 138 139 #endif /* _ASM_ARC_PGALLOC_H */ 140