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 #include <asm-generic/pgalloc.h>
35
36 static inline void
37 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
38 {
39 /*
40 * The cast to long below is OK in 32-bit PAE40 regime with long long pte
41 * Despite "wider" pte, the pte table needs to be in non-PAE low memory
42 * as all higher levels can only hold long pointers.
43 *
44 * The cast itself is needed given simplistic definition of set_pmd()
45 */
46 set_pmd(pmd, __pmd((unsigned long)pte));
47 }
48
49 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte_page)
50 {
51 set_pmd(pmd, __pmd((unsigned long)page_address(pte_page)));
52 }
53
54 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
55 {
56 pgd_t *ret = (pgd_t *) __get_free_page(GFP_KERNEL);
57
58 if (ret) {
59 int num, num2;
60 num = USER_PTRS_PER_PGD + USER_KERNEL_GUTTER / PGDIR_SIZE;
61 memzero(ret, num * sizeof(pgd_t));
62
63 num2 = VMALLOC_SIZE / PGDIR_SIZE;
64 memcpy(ret + num, swapper_pg_dir + num, num2 * sizeof(pgd_t));
65
66 memzero(ret + num + num2,
67 (PTRS_PER_PGD - num - num2) * sizeof(pgd_t));
68
69 }
70 return ret;
71 }
72
73 #if CONFIG_PGTABLE_LEVELS > 3
74
75 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
76 {
77 set_p4d(p4dp, __p4d((unsigned long)pudp));
78 }
79
80 #define __pud_free_tlb(tlb, pmd, addr) pud_free((tlb)->mm, pmd)
81
82 #endif
83
84 #if CONFIG_PGTABLE_LEVELS > 2
85
86 static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
87 {
88 set_pud(pudp, __pud((unsigned long)pmdp));
89 }
90
91 #define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
92
93 #endif
94
95 #define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)
96
97 #endif /* _ASM_ARC_PGALLOC_H */
98
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