40bb0e9042
This reverts commit697ece78f8. The implementation of SWAP on powerpc requires page protection bits to not be one of the least significant PTE bits. Until the SWAP implementation is changed and this requirement voids, we have to keep at least _PAGE_RW outside of the 3 last bits. For now, revert to previous PTE bits order. A further rework may come later. Fixes:697ece78f8("powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits.") Reported-by: Rui Salvaterra <rsalvaterra@gmail.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b34706f8de87f84d135abb5f3ede6b6f16fb1f41.1589969799.git.christophe.leroy@csgroup.eu
46 lines
1.8 KiB
C
46 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_BOOK3S_32_HASH_H
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#define _ASM_POWERPC_BOOK3S_32_HASH_H
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#ifdef __KERNEL__
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/*
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* The "classic" 32-bit implementation of the PowerPC MMU uses a hash
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* table containing PTEs, together with a set of 16 segment registers,
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* to define the virtual to physical address mapping.
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*
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* We use the hash table as an extended TLB, i.e. a cache of currently
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* active mappings. We maintain a two-level page table tree, much
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* like that used by the i386, for the sake of the Linux memory
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* management code. Low-level assembler code in hash_low_32.S
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* (procedure hash_page) is responsible for extracting ptes from the
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* tree and putting them into the hash table when necessary, and
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* updating the accessed and modified bits in the page table tree.
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*/
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#define _PAGE_PRESENT 0x001 /* software: pte contains a translation */
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#define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */
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#define _PAGE_USER 0x004 /* usermode access allowed */
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#define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */
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#define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */
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#define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */
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#define _PAGE_WRITETHRU 0x040 /* W: cache write-through */
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#define _PAGE_DIRTY 0x080 /* C: page changed */
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#define _PAGE_ACCESSED 0x100 /* R: page referenced */
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#define _PAGE_EXEC 0x200 /* software: exec allowed */
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#define _PAGE_RW 0x400 /* software: user write access allowed */
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#define _PAGE_SPECIAL 0x800 /* software: Special page */
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#ifdef CONFIG_PTE_64BIT
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/* We never clear the high word of the pte */
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#define _PTE_NONE_MASK (0xffffffff00000000ULL | _PAGE_HASHPTE)
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#else
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#define _PTE_NONE_MASK _PAGE_HASHPTE
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#endif
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#define _PMD_PRESENT 0
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#define _PMD_PRESENT_MASK (PAGE_MASK)
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#define _PMD_BAD (~PAGE_MASK)
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_BOOK3S_32_HASH_H */
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