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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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2 | #ifndef _ASM_POWERPC_BOOK3S_32_HASH_H |
3 | #define _ASM_POWERPC_BOOK3S_32_HASH_H | |
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4 | #ifdef __KERNEL__ |
5 | ||
6 | /* | |
7 | * The "classic" 32-bit implementation of the PowerPC MMU uses a hash | |
8 | * table containing PTEs, together with a set of 16 segment registers, | |
9 | * to define the virtual to physical address mapping. | |
10 | * | |
11 | * We use the hash table as an extended TLB, i.e. a cache of currently | |
12 | * active mappings. We maintain a two-level page table tree, much | |
13 | * like that used by the i386, for the sake of the Linux memory | |
14 | * management code. Low-level assembler code in hash_low_32.S | |
15 | * (procedure hash_page) is responsible for extracting ptes from the | |
16 | * tree and putting them into the hash table when necessary, and | |
17 | * updating the accessed and modified bits in the page table tree. | |
18 | */ | |
19 | ||
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20 | #define _PAGE_PRESENT 0x001 /* software: pte contains a translation */ |
21 | #define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */ | |
22 | #define _PAGE_USER 0x004 /* usermode access allowed */ | |
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23 | #define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */ |
24 | #define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */ | |
25 | #define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */ | |
26 | #define _PAGE_WRITETHRU 0x040 /* W: cache write-through */ | |
27 | #define _PAGE_DIRTY 0x080 /* C: page changed */ | |
28 | #define _PAGE_ACCESSED 0x100 /* R: page referenced */ | |
385e89d5 | 29 | #define _PAGE_EXEC 0x200 /* software: exec allowed */ |
40bb0e90 | 30 | #define _PAGE_RW 0x400 /* software: user write access allowed */ |
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31 | #define _PAGE_SPECIAL 0x800 /* software: Special page */ |
32 | ||
33 | #ifdef CONFIG_PTE_64BIT | |
34 | /* We never clear the high word of the pte */ | |
35 | #define _PTE_NONE_MASK (0xffffffff00000000ULL | _PAGE_HASHPTE) | |
36 | #else | |
37 | #define _PTE_NONE_MASK _PAGE_HASHPTE | |
38 | #endif | |
39 | ||
40 | #define _PMD_PRESENT 0 | |
41 | #define _PMD_PRESENT_MASK (PAGE_MASK) | |
42 | #define _PMD_BAD (~PAGE_MASK) | |
43 | ||
c605782b | 44 | #endif /* __KERNEL__ */ |
26b6a3d9 | 45 | #endif /* _ASM_POWERPC_BOOK3S_32_HASH_H */ |