Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
24 lines
968 B
C
24 lines
968 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASMPARISC_SHMPARAM_H
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#define _ASMPARISC_SHMPARAM_H
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/*
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* PA-RISC uses virtually indexed & physically tagged (VIPT) caches
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* which has strict requirements when two pages to the same physical
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* address are accessed through different mappings. Read the section
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* "Address Aliasing" in the arch docs for more detail:
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* PA-RISC 1.1 (page 3-6):
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* https://parisc.wiki.kernel.org/images-parisc/6/68/Pa11_acd.pdf
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* PA-RISC 2.0 (page F-5):
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* https://parisc.wiki.kernel.org/images-parisc/7/73/Parisc2.0.pdf
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*
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* For Linux we allow kernel and userspace to map pages on page size
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* granularity (SHMLBA) but have to ensure that, if two pages are
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* mapped to the same physical address, the virtual and physical
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* addresses modulo SHM_COLOUR are identical.
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*/
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#define SHMLBA PAGE_SIZE /* attach addr a multiple of this */
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#define SHM_COLOUR 0x00400000 /* shared mappings colouring */
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#endif /* _ASMPARISC_SHMPARAM_H */
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