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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2020 Synopsys, Inc. (www.synopsys.com)
4 */
5
6/*
7 * Helpers for implemenintg paging levels
8 */
9
10#ifndef _ASM_ARC_PGTABLE_LEVELS_H
11#define _ASM_ARC_PGTABLE_LEVELS_H
12
13#if CONFIG_PGTABLE_LEVELS == 2
14
15/*
16 * 2 level paging setup for software walked MMUv3 (ARC700) and MMUv4 (HS)
17 *
18 * [31] 32 bit virtual address [0]
19 * -------------------------------------------------------
20 * | | <---------- PGDIR_SHIFT ----------> |
21 * | | | <-- PAGE_SHIFT --> |
22 * -------------------------------------------------------
23 * | | |
24 * | | --> off in page frame
25 * | ---> index into Page Table
26 * ----> index into Page Directory
27 *
28 * Given software walk, the vaddr split is arbitrary set to 11:8:13
29 * However enabling of super page in a 2 level regime pegs PGDIR_SHIFT to
30 * super page size.
31 */
32
33#if defined(CONFIG_ARC_HUGEPAGE_16M)
34#define PGDIR_SHIFT 24
35#elif defined(CONFIG_ARC_HUGEPAGE_2M)
36#define PGDIR_SHIFT 21
37#else
38/*
39 * No Super page case
40 * Default value provides 11:8:13 (8K), 10:10:12 (4K)
41 * Limits imposed by pgtable_t only PAGE_SIZE long
42 * (so 4K page can only have 1K entries: or 10 bits)
43 */
44#ifdef CONFIG_ARC_PAGE_SIZE_4K
45#define PGDIR_SHIFT 22
46#else
47#define PGDIR_SHIFT 21
48#endif
49
50#endif
51
52#else /* CONFIG_PGTABLE_LEVELS != 2 */
53
54/*
55 * A default 3 level paging testing setup in software walked MMU
56 * MMUv4 (8K page): <4> : <7> : <8> : <13>
57 * A default 4 level paging testing setup in software walked MMU
58 * MMUv4 (8K page): <4> : <3> : <4> : <8> : <13>
59 */
60#define PGDIR_SHIFT 28
61#if CONFIG_PGTABLE_LEVELS > 3
62#define PUD_SHIFT 25
63#endif
64#if CONFIG_PGTABLE_LEVELS > 2
65#define PMD_SHIFT 21
66#endif
67
68#endif /* CONFIG_PGTABLE_LEVELS */
69
70#define PGDIR_SIZE BIT(PGDIR_SHIFT)
71#define PGDIR_MASK (~(PGDIR_SIZE - 1))
72#define PTRS_PER_PGD BIT(32 - PGDIR_SHIFT)
73
74#if CONFIG_PGTABLE_LEVELS > 3
75#define PUD_SIZE BIT(PUD_SHIFT)
76#define PUD_MASK (~(PUD_SIZE - 1))
77#define PTRS_PER_PUD BIT(PGDIR_SHIFT - PUD_SHIFT)
78#endif
79
80#if CONFIG_PGTABLE_LEVELS > 2
81#define PMD_SIZE BIT(PMD_SHIFT)
82#define PMD_MASK (~(PMD_SIZE - 1))
83#define PTRS_PER_PMD BIT(PUD_SHIFT - PMD_SHIFT)
84#endif
85
86#define PTRS_PER_PTE BIT(PMD_SHIFT - PAGE_SHIFT)
87
88#ifndef __ASSEMBLY__
89
90#if CONFIG_PGTABLE_LEVELS > 3
91#include <asm-generic/pgtable-nop4d.h>
92#elif CONFIG_PGTABLE_LEVELS > 2
93#include <asm-generic/pgtable-nopud.h>
94#else
95#include <asm-generic/pgtable-nopmd.h>
96#endif
97
98/*
99 * 1st level paging: pgd
100 */
101#define pgd_ERROR(e) \
102 pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
103
104#if CONFIG_PGTABLE_LEVELS > 3
105
106/* In 4 level paging, p4d_* macros work on pgd */
107#define p4d_none(x) (!p4d_val(x))
108#define p4d_bad(x) ((p4d_val(x) & ~PAGE_MASK))
109#define p4d_present(x) (p4d_val(x))
110#define p4d_clear(xp) do { p4d_val(*(xp)) = 0; } while (0)
111#define p4d_pgtable(p4d) ((pud_t *)(p4d_val(p4d) & PAGE_MASK))
112#define p4d_page(p4d) virt_to_page(p4d_pgtable(p4d))
113#define set_p4d(p4dp, p4d) (*(p4dp) = p4d)
114
115/*
116 * 2nd level paging: pud
117 */
118#define pud_ERROR(e) \
119 pr_crit("%s:%d: bad pud %08lx.\n", __FILE__, __LINE__, pud_val(e))
120
121#endif
122
123#if CONFIG_PGTABLE_LEVELS > 2
124
125/*
126 * In 3 level paging, pud_* macros work on pgd
127 * In 4 level paging, pud_* macros work on pud
128 */
129#define pud_none(x) (!pud_val(x))
130#define pud_bad(x) ((pud_val(x) & ~PAGE_MASK))
131#define pud_present(x) (pud_val(x))
132#define pud_clear(xp) do { pud_val(*(xp)) = 0; } while (0)
133#define pud_pgtable(pud) ((pmd_t *)(pud_val(pud) & PAGE_MASK))
134#define pud_page(pud) virt_to_page(pud_pgtable(pud))
135#define set_pud(pudp, pud) (*(pudp) = pud)
136
137/*
138 * 3rd level paging: pmd
139 */
140#define pmd_ERROR(e) \
141 pr_crit("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, pmd_val(e))
142
143#define pmd_pfn(pmd) ((pmd_val(pmd) & PMD_MASK) >> PAGE_SHIFT)
144#define pfn_pmd(pfn,prot) __pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
145#define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot)
146
147#endif
148
149/*
150 * Due to the strange way generic pgtable level folding works, the pmd_* macros
151 * - are valid even for 2 levels (which supposedly only has pgd - pte)
152 * - behave differently for 2 vs. 3
153 * In 2 level paging (pgd -> pte), pmd_* macros work on pgd
154 * In 3+ level paging (pgd -> pmd -> pte), pmd_* macros work on pmd
155 */
156#define pmd_none(x) (!pmd_val(x))
157#define pmd_bad(x) ((pmd_val(x) & ~PAGE_MASK))
158#define pmd_present(x) (pmd_val(x))
159#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0)
160#define pmd_page_vaddr(pmd) (pmd_val(pmd) & PAGE_MASK)
161#define pmd_pfn(pmd) ((pmd_val(pmd) & PAGE_MASK) >> PAGE_SHIFT)
162#define pmd_page(pmd) virt_to_page((void *)pmd_page_vaddr(pmd))
163#define set_pmd(pmdp, pmd) (*(pmdp) = pmd)
164#define pmd_pgtable(pmd) ((pgtable_t) pmd_page(pmd))
165
166/*
167 * 4th level paging: pte
168 */
169#define pte_ERROR(e) \
170 pr_crit("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
171
172#define PFN_PTE_SHIFT PAGE_SHIFT
173#define pte_none(x) (!pte_val(x))
174#define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
175#define pte_clear(mm,addr,ptep) set_pte_at(mm, addr, ptep, __pte(0))
176#define pte_page(pte) pfn_to_page(pte_pfn(pte))
177#define set_pte(ptep, pte) ((*(ptep)) = (pte))
178#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
179#define pfn_pte(pfn, prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
180#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
181
182#ifdef CONFIG_ISA_ARCV2
183#define pmd_leaf(x) (pmd_val(x) & _PAGE_HW_SZ)
184#endif
185
186#endif /* !__ASSEMBLY__ */
187
188#endif