1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
6 * -"/proc/meminfo | grep PageTables" kept on increasing
7 * Recently added pgtable dtor was not getting called.
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.
16 * -Added pgtable ctor/dtor used for pgtable mem accounting
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)
26 * Amit Bhor, Sameer Dhavale: Codito Technologies 2004
29 #ifndef _ASM_ARC_PGALLOC_H
30 #define _ASM_ARC_PGALLOC_H
33 #include <linux/log2.h>
36 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
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.
43 * The cast itself is needed given simplistic definition of set_pmd()
45 set_pmd(pmd, __pmd((unsigned long)pte));
48 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte_page)
50 set_pmd(pmd, __pmd((unsigned long)page_address(pte_page)));
53 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
55 pgd_t *ret = (pgd_t *) __get_free_page(GFP_KERNEL);
59 num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE;
60 memzero(ret, num * sizeof(pgd_t));
62 num2 = VMALLOC_SIZE / PGDIR_SIZE;
63 memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t));
65 memzero(ret + num + num2,
66 (PTRS_PER_PGD - num - num2) * sizeof(pgd_t));
72 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
74 free_page((unsigned long)pgd);
77 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
81 pte = (pte_t *) __get_free_page(GFP_KERNEL | __GFP_ZERO);
86 static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
90 page = (pgtable_t)alloc_page(GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT);
94 if (!pgtable_pte_page_ctor(page)) {
102 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
104 free_page((unsigned long)pte);
107 static inline void pte_free(struct mm_struct *mm, pgtable_t pte_page)
109 pgtable_pte_page_dtor(pte_page);
110 __free_page(pte_page);
113 #define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)
115 #endif /* _ASM_ARC_PGALLOC_H */