1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 4 * 5 * vineetg: June 2011 6 * -"/proc/meminfo | grep PageTables" kept on increasing 7 * Recently added pgtable dtor was not getting called. 8 * 9 * vineetg: May 2011 10 * -Variable pg-sz means that Page Tables could be variable sized themselves 11 * So calculate it based on addr traversal split [pgd-bits:pte-bits:xxx] 12 * -Page Table size capped to max 1 to save memory - hence verified. 13 * -Since these deal with constants, gcc compile-time optimizes them. 14 * 15 * vineetg: Nov 2010 16 * -Added pgtable ctor/dtor used for pgtable mem accounting 17 * 18 * vineetg: April 2010 19 * -Switched pgtable_t from being struct page * to unsigned long 20 * =Needed so that Page Table allocator (pte_alloc_one) is not forced to 21 * deal with struct page. That way in future we can make it allocate 22 * multiple PG Tbls in one Page Frame 23 * =sweet side effect is avoiding calls to ugly page_address( ) from the 24 * pg-tlb allocator sub-sys (pte_alloc_one, ptr_free, pmd_populate) 25 * 26 * Amit Bhor, Sameer Dhavale: Codito Technologies 2004 27 */ 28 29 #ifndef _ASM_ARC_PGALLOC_H 30 #define _ASM_ARC_PGALLOC_H 31 32 #include <linux/mm.h> 33 #include <linux/log2.h> 34 35 static inline void 36 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte) 37 { 38 /* 39 * The cast to long below is OK in 32-bit PAE40 regime with long long pte 40 * Despite "wider" pte, the pte table needs to be in non-PAE low memory 41 * as all higher levels can only hold long pointers. 42 * 43 * The cast itself is needed given simplistic definition of set_pmd() 44 */ 45 set_pmd(pmd, __pmd((unsigned long)pte)); 46 } 47 48 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte_page) 49 { 50 set_pmd(pmd, __pmd((unsigned long)page_address(pte_page))); 51 } 52 53 static inline pgd_t *pgd_alloc(struct mm_struct *mm) 54 { 55 pgd_t *ret = (pgd_t *) __get_free_page(GFP_KERNEL); 56 57 if (ret) { 58 int num, num2; 59 num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE; 60 memzero(ret, num * sizeof(pgd_t)); 61 62 num2 = VMALLOC_SIZE / PGDIR_SIZE; 63 memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t)); 64 65 memzero(ret + num + num2, 66 (PTRS_PER_PGD - num - num2) * sizeof(pgd_t)); 67 68 } 69 return ret; 70 } 71 72 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) 73 { 74 free_page((unsigned long)pgd); 75 } 76 77 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) 78 { 79 pte_t *pte; 80 81 pte = (pte_t *) __get_free_page(GFP_KERNEL | __GFP_ZERO); 82 83 return pte; 84 } 85 86 static inline pgtable_t pte_alloc_one(struct mm_struct *mm) 87 { 88 struct page *page; 89 90 page = (pgtable_t)alloc_page(GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT); 91 if (!page) 92 return NULL; 93 94 if (!pgtable_pte_page_ctor(page)) { 95 __free_page(page); 96 return NULL; 97 } 98 99 return page; 100 } 101 102 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) 103 { 104 free_page((unsigned long)pte); 105 } 106 107 static inline void pte_free(struct mm_struct *mm, pgtable_t pte_page) 108 { 109 pgtable_pte_page_dtor(pte_page); 110 __free_page(pte_page); 111 } 112 113 #define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte) 114 115 #endif /* _ASM_ARC_PGALLOC_H */ 116