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
36static inline void
37pmd_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
49static 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
54static 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
75static 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
86static 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