1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Copyright (C) 2020 Synopsys, Inc. (www.synopsys.com)
7 * Helpers for implemenintg paging levels
10 #ifndef _ASM_ARC_PGTABLE_LEVELS_H
11 #define _ASM_ARC_PGTABLE_LEVELS_H
14 * 2 level paging setup for software walked MMUv3 (ARC700) and MMUv4 (HS)
16 * [31] 32 bit virtual address [0]
17 * -------------------------------------------------------
18 * | | <---------- PGDIR_SHIFT ----------> |
19 * | | | <-- PAGE_SHIFT --> |
20 * -------------------------------------------------------
22 * | | --> off in page frame
23 * | ---> index into Page Table
24 * ----> index into Page Directory
26 * Given software walk, the vaddr split is arbitrary set to 11:8:13
27 * However enabling of super page in a 2 level regime pegs PGDIR_SHIFT to
31 #if defined(CONFIG_ARC_HUGEPAGE_16M)
32 #define PGDIR_SHIFT 24
33 #elif defined(CONFIG_ARC_HUGEPAGE_2M)
34 #define PGDIR_SHIFT 21
38 * Default value provides 11:8:13 (8K), 10:10:12 (4K)
39 * Limits imposed by pgtable_t only PAGE_SIZE long
40 * (so 4K page can only have 1K entries: or 10 bits)
42 #ifdef CONFIG_ARC_PAGE_SIZE_4K
43 #define PGDIR_SHIFT 22
45 #define PGDIR_SHIFT 21
50 #define PGDIR_SIZE BIT(PGDIR_SHIFT) /* vaddr span, not PDG sz */
51 #define PGDIR_MASK (~(PGDIR_SIZE - 1))
53 #define PTRS_PER_PGD BIT(32 - PGDIR_SHIFT)
55 #define PTRS_PER_PTE BIT(PGDIR_SHIFT - PAGE_SHIFT)
59 #include <asm-generic/pgtable-nopmd.h>
62 * 1st level paging: pgd
64 #define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
65 #define pgd_offset(mm, addr) (((mm)->pgd) + pgd_index(addr))
66 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
67 #define pgd_ERROR(e) \
68 pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
71 * Due to the strange way generic pgtable level folding works, in a 2 level
72 * setup, pmd_val() returns pgd, so these pmd_* macros actually work on pgd
74 #define pmd_none(x) (!pmd_val(x))
75 #define pmd_bad(x) ((pmd_val(x) & ~PAGE_MASK))
76 #define pmd_present(x) (pmd_val(x))
77 #define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0)
78 #define pmd_page_vaddr(pmd) (pmd_val(pmd) & PAGE_MASK)
79 #define pmd_page(pmd) virt_to_page(pmd_page_vaddr(pmd))
80 #define set_pmd(pmdp, pmd) (*(pmdp) = pmd)
81 #define pmd_pgtable(pmd) ((pgtable_t) pmd_page_vaddr(pmd))
83 #define pte_ERROR(e) \
84 pr_crit("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
86 #define pte_none(x) (!pte_val(x))
87 #define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
88 #define pte_clear(mm,addr,ptep) set_pte_at(mm, addr, ptep, __pte(0))
89 #define pte_page(pte) pfn_to_page(pte_pfn(pte))
90 #define set_pte(ptep, pte) ((*(ptep)) = (pte))
91 #define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
92 #define pfn_pte(pfn, prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
93 #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
95 #ifdef CONFIG_ISA_ARCV2
96 #define pmd_leaf(x) (pmd_val(x) & _PAGE_HW_SZ)
99 #endif /* !__ASSEMBLY__ */