include/asm/pgtable-levels.h

1 /* SPDX-License-Identifier: GPL-2.0-only */
19  * -------------------------------------------------------
20  * |               | <---------- PGDIR_SHIFT ----------> |
21  * |               |                | <-- PAGE_SHIFT --> |
22  * -------------------------------------------------------
24  *       |                  |                --> off in page frame
25  *       |                  ---> index into Page Table
26  *       ----> index into Page Directory
36 #define PGDIR_SHIFT		21
40  * Default value provides 11:8:13 (8K), 10:10:12 (4K)
42  * (so 4K page can only have 1K entries: or 10 bits)
47 #define PGDIR_SHIFT		21
56  *   MMUv4 (8K page): <4> : <7> : <8> : <13>
58  *   MMUv4 (8K page): <4> : <3> : <4> : <8> : <13>
65 #define PMD_SHIFT		21
71 #define PGDIR_MASK		(~(PGDIR_SIZE - 1))
72 #define PTRS_PER_PGD		BIT(32 - PGDIR_SHIFT)
76 #define PUD_MASK		(~(PUD_SIZE - 1))
77 #define PTRS_PER_PUD		BIT(PGDIR_SHIFT - PUD_SHIFT)
82 #define PMD_MASK		(~(PMD_SIZE - 1))
83 #define PTRS_PER_PMD		BIT(PUD_SHIFT - PMD_SHIFT)
86 #define PTRS_PER_PTE		BIT(PMD_SHIFT - PAGE_SHIFT)
91 #include <asm-generic/pgtable-nop4d.h>
93 #include <asm-generic/pgtable-nopud.h>
95 #include <asm-generic/pgtable-nopmd.h>
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